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Last Updated :2024/10/09

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Master

Affiliation (Master)

  • Faculty of Veterinary Medicine　Veterinary Medicine　Disease Control

Affiliation (Master)

  • Faculty of Veterinary Medicine　Veterinary Medicine　Disease Control

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Degree

  • PhD（Hokkaido University）

Profile and Settings

  • Name (Japanese)

    Sakoda

  • Name (Kana)

    Yoshihiro

  • Name

    200901004853911511

Alternate Names

Achievement

Research Areas

  • Life sciences / Veterinary medicine
  • Life sciences / Virology

Research Experience

  • 2014/04 - Today Hokkaido University
  • 2005 - 2014/03 Hokkaido University Graduate School of Veterinary Medicine
  • 2001 - 2005 Hokkaido University Graduate School of Veterinary Medicine

Education

  •        - 1994  Hokkaido University  School of Veterinary Medicine
  •        - 1994  Hokkaido University  Faculty of Veterinary Medicine

Awards

  • 2016 北海道大学 北海道大学研究総長賞
     
    受賞者: 迫田 義博
  • 2014 北海道大学 北海道大学研究総長賞
     
    受賞者: 迫田 義博
  • 2013/03 日本獣医学会 日本獣医学会賞
     「ペスチウイルスの分子疫学と病原性に関する研究」 
    受賞者: 迫田 義博
  • 2008 若手農林水産研究者表彰
     「高病原性鳥インフルエンザの診断と予防法の開発に関する研究」 
    受賞者: 迫田 義博
  • 2006 アジア獣医系大学協会 アジア獣医系大学協会賞
     「高病原性鳥インフルエンザの疫学と病原性に関する研究」 
    受賞者: 迫田 義博

Published Papers

  • Takaya Ichikawa, Takahiro Hiono, Masatoshi Okamatsu, Junki Maruyama, Daiki Kobayashi, Keita Matsuno, Hiroshi Kida, Yoshihiro Sakoda
    Archives of Virology 0304-8608 2024/10
  • Ariunbold Munkhtsetseg, Enkhbaatar Batmagnai, Myagmarsuren Odonchimeg, Gombodash Ganbat, Yondonjamts Enkhmandakh, Gantulga Ariunbold, Tsedenbal Dolgorsuren, Raadan Odbileg, Purevtseren Dulam, Bumduuren Tuvshintulga, Chihiro Sugimoto, Yoshihiro Sakoda, Junya Yamagishi, Dashzevge Erdenechimeg
    Veterinary journal (London, England : 1997) 308 106231 - 106231 2024/08/28 
    Canine distemper virus (CDV) triggers a severe, often fatal disease in dogs and wildlife known as canine distemper (CD). Prior research has noted significant genetic diversity and recombination among CDV isolates from different geographical regions, potentially contributing to vaccine failures. Despite this, no genetic characterization of Mongolian CDVs has been conducted. This study, isolated CDVs from three unvaccinated dogs: two 10-month-old mixed-breeds and an 18-month-old Samoyed. All exhibited CD symptoms and subsequently died. Virus isolation was conducted using Vero/dog SLAM cells, with genome sequencing performed via nanopore technology. The mixed-breed dogs were infected with non-recombinant CDV isolates, forming a sister clade to the Asia-1 lineage prevalent in Asia. The Samoyed was infected with a non-recombinant CDV isolate, classifying as Asia-4 lineage sporadically reported in some Asian countries. This sequencing data offers foundational information on genetic diversity, aiding CD control measure development and benefiting future Eurasia and Asian studies.
  • Yik Lim Hew, Takahiro Hiono, Isabella Monne, Kei Nabeshima, Saki Sakuma, Asuka Kumagai, Shunya Okamura, Kosuke Soda, Hiroshi Ito, Mana Esaki, Kosuke Okuya, Makoto Ozawa, Toshiyo Yabuta, Hiroki Takakuwa, Linh Bao Nguyen, Norikazu Isoda, Kohtaro Miyazawa, Manabu Onuma, Yoshihiro Sakoda
    Emerging infectious diseases 30 (9) 1912 - 1917 2024/08/06 
    We isolated highly pathogenic avian influenza (HPAI) H5N5 and H5N1 viruses from crows in Hokkaido, Japan, during winter 2023-24. They shared genetic similarity with HPAI H5N5 viruses from northern Europe but differed from those in Asia. Continuous monitoring and rapid information sharing between countries are needed to prevent HPAI virus transmission.
  • Keisuke Kuwata, Naotoshi Kuninaga, Yoko Kimura, Kohei Makita, Norikazu Isoda, Yukio Shimizu, Yoshihiro Sakoda
    Pathogens (Basel, Switzerland) 13 (8) 2024/07/25 
    In 2018, classical swine fever (CSF) reemerged in Gifu Prefecture, Japan, after 26 years of absence, and vaccination of domestic pigs using a live attenuated vaccine was initiated in 2019. Because the vaccine efficacy in piglets is influenced by the maternal antibody levels, vaccination should be administered at the optimal age by assuming the antibody level in sows. In this study, the shift in the antibody titer distribution in sows due to the initiation of vaccination to naïve herds and its influence on the vaccine-induced immunity rate in fattening pigs were investigated for 3 years. The results indicated that higher antibody titers were induced in first-generation sows after vaccine initiation because they were immunologically naïve, but the distribution of antibody titers shifted to lower levels along with their replacement with second-generation sows. The average vaccination age of fattening pigs became earlier year by year, and the vaccine-induced antibody rate was almost ≥80%. Based on the estimation of the optimal age for vaccination, it was found that vaccination at a younger age may reduce the risk of CSF infection. Taken together, the risk of CSF outbreaks can be reduced by administering vaccines at the optimal age based on the sequential monitoring of the sow's immune status.
  • Loc Tan Huynh, Mikihiro Otsuka, Maya Kobayashi, Hung Dinh Ngo, Lim Yik Hew, Takahiro Hiono, Norikazu Isoda, Yoshihiro Sakoda
    Viruses 16 (7) 2024/07/12 
    Chimeric marker vaccine candidates, vGPE-/PAPeV Erns and vGPE-/PhoPeV Erns, have been generated and their efficacy and capability to differentiate infected from vaccinated animals were confirmed in previous studies. The safety profile of the two chimeric marker vaccine candidates, particularly in the potential reversion to virulence, was evaluated. Each virus was administered to pigs with a dose equivalent to the vaccination dose, and pooled tonsil homogenates were subsequently inoculated into further pigs. Chimeric virus vGPE-/PAPeV Erns displayed the most substantial attenuation, achieving this within only two passages, whereas vGPE-/PhoPeV Erns was detectable until the third passage and disappeared entirely by the fourth passage. The vGPE- strain, assessed alongside, consistently exhibited stable virus recovery across each passage without any signs of increased virulence in pigs. In vitro assays revealed that the type I interferon-inducing capacity of vGPE-/PAPeV Erns was significantly higher than that of vGPE-/PhoPeV Erns and vGPE-. In conclusion, the safety profile of the two chimeric marker vaccine candidates was affirmed. Further research is essential to ensure the stability of their attenuation and safety in diverse pig populations.
  • Nergui Davaasuren, Vahid Molaee, Tseren-Ochir Erdene-Ochir, Guugandaa Nyamdavaa, Sumiya Ganzorig, Maurizio Mazzei, Yoshihiro Sakoda, Gesine Lühken, Sharav Tumenjargal
    Veterinary research communications 48 (3) 1955 - 1962 2024/06 
    The ovine maedi-visna virus (MVV) and caprine arthritis-encephalitis virus (CAEV) are small ruminant lentiviruses (SRLVs) with striking genetic and structural similarities. The presence of SRLV in Mongolian sheep and goats was serologically demonstrated more than a decade ago; however, the viral genotype remains unknown. In total, 329 blood samples were collected from two sheep breeds (i.e., Khalkha and Sumber) in Tov, Govisumber, Arkhangay, Dornogovi, Zavkhan, and Sukhbaatar provinces, Mongolia. Serological and phylogenetic analyses were performed regardless of any apparent clinical signs, although most of the animals appeared healthy. All sheep in three of the six provinces were seronegative, whereas the seroprevalence in the Tov, Govisumber, and Zavkhan provinces averaged 7.9%. Genomic DNA from seropositive animals was tested using hemi-nested polymerase chain reaction, and sub-genomic SRLV sequences were determined from nine samples. Mongolian SRLV sequences clustered within the divergent subtype A22, which was previously found only in Fertile Crescent regions, including Lebanon, Jordan, and Iran, where the first sheep-domestication (Ovis aries) occurred. According to the phylogenetic analysis, genotype A has two ancestors from the ancient Fertile Crescent: (1) Turkish strains and (2) Iranian, Jordanian, and Lebanese strains. The first ancestor spread westward, whereas the second spread eastward, ultimately reaching Mongolia.
  • Mariko Miki, Ryo Daniel Obara, Kyohei Nishimura, Takao Shishido, Yoshinori Ikenaka, Ryoko Oka, Kenji Sato, Shouta M M Nakayama, Takashi Kimura, Atsushi Kobayashi, Keisuke Aoshima, Keisuke Saito, Takahiro Hiono, Norikazu Isoda, Yoshihiro Sakoda
    Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians 55 (2) 313 - 321 2024/06 
    High pathogenicity avian influenza is an acute zoonotic disease with high mortality in birds caused by a high pathogenicity avian influenza virus (HPAIV). Recently, HPAIV has rapidly spread worldwide and has killed many wild birds, including endangered species. Baloxavir marboxil (BXM), an anti-influenza agent used for humans, was reported to reduce mortality and virus secretion from HPAIV-infected chickens (Gallus domesticus, order Galliformes) at a dosage of ≥2.5 mg/kg when administered simultaneously with viral challenge. Application of this treatment to endangered birds requires further information on potential avian-specific toxicity caused by repeated exposure to BXM over the long term. To obtain information of potential avian-specific toxicity, a 4-wk oral repeated-dose study of BXM was conducted in chickens (n = 6 or 7 per group), which are commonly used as laboratory avian species. The study was conducted in reference to the human pharmaceutical guidelines for nonclinical repeated-dose drug toxicity studies to evaluate systemic toxicity and exposure. No adverse changes were observed in any organs examined, and dose proportional increases in systemic exposure to active pharmaceutical ingredients were noted from 12.5 to 62.5 mg/kg per day. BXM showed no toxicity to chickens at doses of up to 62.5 mg/kg per day, at which systemic exposure was approximately 71 times higher than systemic exposure at 2.5 mg/kg, the reported efficacious dosage amount, in HPAIV-infected chickens. These results also suggest that BXM could be considered safe for treating HPAIV-infected endangered birds due to its high safety margin compared with the efficacy dose. The data in this study could contribute to the preservation of endangered birds by using BXM as a means of protecting biodiversity.
  • Yuji Fujii, Tatsunori Masatani, Shoko Nishiyama, Tatsuki Takahashi, Misuzu Okajima, Fumiki Izumi, Yoshihiro Sakoda, Ayato Takada, Makoto Ozawa, Makoto Sugiyama, Naoto Ito
    Virology 596 110114 - 110114 2024/05/18 
    Avian rotaviruses A (RVAs) are occasionally transmitted to animals other than the original hosts across species barriers. Information on RVAs carried by various bird species is important for identifying the origin of such interspecies transmission. In this study, to facilitate an understanding of the ecology of RVAs from wild birds, we characterized all of the genes of an RVA strain, JC-105, that was detected in a fecal sample of a large-billed crow (Corvus macrorhynchos) in Japan. All of the genes of this strain except for the VP4 and VP7 genes, which were classified as novel genotypes (P[56] and G40, respectively), were closely related to those of the avian-like RVA strain detected from a raccoon, indicating the possibility that crows had been involved in the transmission of avian RVAs to raccoons. Our findings highlight the need for further viral investigations in wild birds and mammals to understand the mechanisms of avian-to-mammal RVA transmission.
  • Loc Tan Huynh, Eun-Ju Sohn, Youngmin Park, Juhun Kim, Tomohiko Shimoda, Takahiro Hiono, Norikazu Isoda, Sung-Hee Hong, Ha-Na Lee, Yoshihiro Sakoda
    Frontiers in Microbiology 15 1383976 - 1383976 2024/04/11 
    Background It is essential to consider a practical antibody test to successfully implement marker vaccines and validate vaccination efficacy against classical swine fever virus (CSFV). The test should include a serological antibody assay, combined with a tool for differentiating infected from vaccinated animals (DIVA). The immunochromatographic test strip (ICS) has been exclusively designed for detecting CSFV E2 antibodies while lacking in detecting Erns antibodies, which can be employed and satisfy DIVA strategy. This study developed a novel ICS for detecting CSFV E2/Erns dual-antibody. The effectiveness of ICS in evaluating the DIVA capability of two novel chimeric pestivirus vaccine candidates was assessed. Methods Recombinant E2 or Erns protein was transiently expressed in the plant benthamiana using Agrobacterium tumefaciens. ICS was subsequently assembled, and goat anti-rabbit IgG and recombinant CSFV E2 or Erns protein were plated onto the nitrocellulose membrane as control and test lines, respectively. The sensitivity and specificity of ICS were evaluated using sera with different neutralizing antibody titers or positive for antibodies against CSFV and other pestiviruses. The coincidence rates for detecting E2 and Erns antibodies between ICS and commercial enzyme-linked immunosorbent assay (ELISA) kits were also computed. ICS performance for DIVA capability was evaluated using sera from pigs vaccinated with conventional vaccine or chimeric vaccine candidates. Results E2 and Erns proteins were successfully expressed in N. benthamiana-produced recombinant proteins. ICS demonstrated high sensitivity in identifying CSFV E2 and Erns antibodies, even at the low neutralizing antibody titers. No cross-reactivity with antibodies from other pestiviruses was confirmed using ICS. There were high agreement rates of 93.0 and 96.5% between ICS and two commercial ELISA kits for E2 antibody testing. ICS also achieved strong coincidence rates of 92.9 and 89.3% with two ELISA kits for Erns antibody detection. ICS confirmed the absence of CSFV Erns-specific antibodies in sera from pigs vaccinated with chimeric vaccine candidates. Conclusion E2 and Erns proteins derived from the plant showed great potential and can be used to engineer a CSFV E2/Erns dual-antibody ICS. The ICS was also highly sensitive and specific for detecting CSFV E2 and Erns antibodies. Significantly, ICS can fulfill the DIVA concept by incorporating chimeric vaccine candidates.
  • Lim Yik Hew, Norikazu Isoda, Fumihito Takaya, Kohei Ogasawara, Daiki Kobayashi, Loc Tan Huynh, Tatsuru Morita, Rio Harada, Nikolay Gennadievich Zinyakov, Dmitriy Borisovich Andreychuk, Ilya Alexandrovich Chvala, Viktor Nikolaevich Irza, Yukiko Watanabe, Hiroko Fujita, Keisuke Saito, Takahiro Hiono, Yoshihiro Sakoda
    Transboundary and Emerging Diseases 2024 1 - 18 1865-1674 2024/03/14 
    High pathogenicity avian influenza (HPAI) has impacted poultry and wild birds globally. The number of H5 HPAI virus (HPAIV) infection cases in wild birds in Hokkaido (Northern Japan) was high in the last two seasons, contributing to virus spillover to resident birds and poultry. Therefore, H5 HPAIVs in birds and mammals in Hokkaido in winter 2022–2023 and 2023–2024 were monitored and viruses were phylogenetically, antigenically, and pathogenetically characterized. Thirty HPAIV isolates were subtyped and pathotyped by sequencing the hemagglutinin (HA) gene of viruses. Phylogenetic analysis of the HA gene revealed that all isolated HPAIVs were categorized into clade 2.3.4.4b and divided into three groups (G2b, G2c, and G2d). Most isolates belonging to subgroup G2d clustered with isolates in winter 2021–2022 in Hokkaido. The other isolates were categorized into two subgroups, G2b and G2c, mainly composed of isolates in Honshu Island in winter 2021–2022 and 2022–2023, respectively. Two H5 HPAIVs isolated in Eastern Russia in spring and autumn 2022 were genetically close to most Hokkaido isolates (G2d), and a virus isolated in Hokkaido in November 2023 was also grouped in subgroup G2d. Further analysis of all eight gene segments identified six types of gene constellations. Cross-hemagglutination inhibition test indicated that the antigenicity of H5 HPAIVs isolated in the last several seasons was similar within them but slightly different from that in the 2010s. Three chicken breeds were intranasally challenged with four representative isolates to assess their pathogenicity. All chickens except one broiler chicken were dead until 5-day postchallenge with different pathogenicity of these viruses. The pathogenicity of one HPAIV strain was significantly lower in broiler chickens than in layer chickens. The mixture of multiple characteristics of HPAIVs in Hokkaido was confirmed by bird migration routes. Thus, many HPAIVs can be brought and scattered anywhere on Earth.
  • Tomokazu Tamura, Hirotaka Yamamoto, Saho Ogino, Yuhei Morioka, Shuhei Tsujino, Rigel Suzuki, Takahiro Hiono, Saori Suzuki, Norikazu Isoda, Yoshihiro Sakoda, Takasuke Fukuhara
    Journal of virology 98 (3) e0163823  2024/02/14 
    Reverse genetics systems have played a central role in developing recombinant viruses for a wide spectrum of virus research. The circular polymerase extension reaction (CPER) method has been applied to studying positive-strand RNA viruses, allowing researchers to bypass molecular cloning of viral cDNA clones and thus leading to the rapid generation of recombinant viruses. However, thus far, the CPER protocol has only been established using cap-dependent RNA viruses. Here, we demonstrate that a modified version of the CPER method can be successfully applied to positive-strand RNA viruses that use cap-independent, internal ribosomal entry site (IRES)-mediated translation. As a proof-of-concept, we employed mammalian viruses with different types (classes I, II, and III) of IRES to optimize the CPER method. Using the hepatitis C virus (HCV, class III), we found that inclusion in the CPER assembly of an RNA polymerase I promoter and terminator, instead of those from polymerase II, allowed greater viral production. This approach was also successful in generating recombinant bovine viral diarrhea virus (class III) following transfection of MDBK/293T co-cultures to overcome low transfection efficiency. In addition, we successfully generated the recombinant viruses from clinical specimens. Our modified CPER could be used for producing hepatitis A virus (HAV, type I) as well as de novo generation of encephalomyocarditis virus (type II). Finally, we generated recombinant HCV and HAV reporter viruses that exhibited replication comparable to that of the wild-type parental viruses. The recombinant HAV reporter virus helped evaluate antivirals. Taking the findings together, this study offers methodological advances in virology.IMPORTANCEThe lack of versatility of reverse genetics systems remains a bottleneck in viral research. Especially when (re-)emerging viruses reach pandemic levels, rapid characterization and establishment of effective countermeasures using recombinant viruses are beneficial in disease control. Indeed, numerous studies have attempted to establish and improve the methods. The circular polymerase extension reaction (CPER) method has overcome major obstacles in generating recombinant viruses. However, this method has not yet been examined for positive-strand RNA viruses that use cap-independent, internal ribosome entry site-mediated translation. Here, we engineered a suitable gene cassette to expand the CPER method for all positive-strand RNA viruses. Furthermore, we overcame the difficulty of generating recombinant viruses because of low transfection efficiency. Using this modified method, we also successfully generated reporter viruses and recombinant viruses from a field sample without virus isolation. Taking these findings together, our adapted methodology is an innovative technology that could help advance virologic research.
  • Annie Kalonda, Ngonda Saasa, Masahiro Kajihara, Naganori Nao, Ladslav Moonga, Joseph Ndebe, Akina Mori-Kajihara, Andrew Nalishuwa Mukubesa, Yoshihiro Sakoda, Hirofumi Sawa, Ayato Takada, Edgar Simulundu
    Microorganisms 12 (2) 2024/02/08 
    Poultry production is essential to the economy and livelihood of many rural Zambian households. However, the industry is threatened by infectious diseases, particularly Newcastle disease virus (NDV) infection. Therefore, this study employed next-generation sequencing to characterise six NDV isolates from poultry in Zambia's live bird markets (LBMs) and wild waterfowl. Four NDV isolates were detected from 410 faecal samples collected from chickens in LBMs in Lusaka and two from 2851 wild birds from Lochinvar National Park. Phylogenetic analysis revealed that the four NDVs from LBM clustered in genotype VII and sub-genotype VII.2 were closely related to viruses previously isolated in Zambia and other Southern African countries, suggesting possible local and regional transboundary circulation of the virus. In contrast, the two isolates from wild birds belonged to class I viruses, genotype 1, and were closely related to isolates from Europe and Asia, suggesting the possible introduction of these viruses from Eurasia, likely through wild bird migration. The fusion gene cleavage site motif for all LBM-associated isolates was 112RRQKR|F117, indicating that the viruses are virulent, while the isolates from wild waterfowl had the typical 112ERQER|L117 avirulent motif. This study demonstrates the circulation of virulent NDV strains in LBMs and has, for the first time, characterised NDV from wild birds in Zambia. The study further provides the first whole genomes of NDV sub-genotype VII.2 and genotype 1 from Zambia and stresses the importance of surveillance and molecular analysis for monitoring the circulation of NDV genotypes and viral evolution.
  • Keiichi Taniguchi, Takeshi Noshi, Shinya Omoto, Akihiko Sato, Takao Shishido, Keita Matsuno, Masatoshi Okamatsu, Scott Krauss, Richard J Webby, Yoshihiro Sakoda, Hiroshi Kida
    Archives of virology 169 (2) 29 - 29 2024/01/12 
    Genetic reassortment of avian, swine, and human influenza A viruses (IAVs) poses potential pandemic risks. Surveillance is important for influenza pandemic preparedness, but the susceptibility of zoonotic IAVs to the cap-dependent endonuclease inhibitor baloxavir acid (BXA) has not been thoroughly researched. Although an amino acid substitution at position 38 in the polymerase acidic protein (PA/I38) in seasonal IAVs reduces BXA susceptibility, PA polymorphisms at position 38 are rarely seen in zoonotic IAVs. Here, we examined the impact of PA/I38 substitutions on the BXA susceptibility of recombinant A(H5N1) viruses. PA mutants that harbored I38T, F, and M were 48.2-, 24.0-, and 15.5-fold less susceptible, respectively, to BXA than wild-type A(H5N1) but were susceptible to the neuraminidase inhibitor oseltamivir acid and the RNA polymerase inhibitor favipiravir. PA mutants exhibited significantly impaired replicative fitness in Madin-Darby canine kidney cells at 24 h postinfection. In addition, in order to investigate new genetic markers for BXA susceptibility, we screened geographically and temporally distinct IAVs isolated worldwide from birds and pigs. The results showed that BXA exhibited antiviral activity against avian and swine viruses with similar levels to seasonal isolates. All viruses tested in the study lacked the PA/I38 substitution and were susceptible to BXA. Isolates harboring amino acid polymorphisms at positions 20, 24, and 37, which have been implicated in the binding of BXA to the PA endonuclease domain, were also susceptible to BXA. These results suggest that monitoring of the PA/I38 substitution in animal-derived influenza viruses is important for preparedness against zoonotic influenza virus outbreaks.
  • Yume MIMURA, Takahiro HIONO, Loc Tan HUYNH, Saho OGINO, Maya KOBAYASHI, Norikazu ISODA, Yoshihiro SAKODA
    Journal of Veterinary Medical Science 86 (4) 389 - 395 0916-7250 2024 
    Pestiviruses are classified into two biotypes based on their cytopathogenicity. As the majority of pestivirus field isolates are noncytopathogenic, their titration requires alternative methods rather than direct observation of cytopathogenic effects, such as immunostaining using specific antibodies or interference with cytopathogenic strains. However, these methods require microscopic observation to assess virus growth, which is time- and labor-intensive, especially when handling several samples. In this study, we developed a novel luciferase-based pestivirus titration method using the superinfection exclusion phenomenon with recombinant reporter pestiviruses that possessed an 11-amino-acid subunit derived from NanoLuc luciferase (HiBiT). In this method, swine kidney cells were inoculated with classical swine fever virus (CSFV) and superinfected with the reporter CSFV vGPE-/HiBiT 5 days postinoculation. Virus titer was determined based on virus growth measured in luminescence using the culture fluid 3 days after superinfection; the resultant virus titer was comparable to that obtained by immunoperoxidase staining. Furthermore, this method has proven to be applicable for the titration of border disease virus (BDV) by superinfection with both the homologous reporter BDV and heterologous reporter CSFV, suggesting that this novel virus titration method is a simple technique for automated virus detection based on the luciferase system.
  • Makoto Ukita, Keisuke Kuwata, Eiji Tanaka, Ryota Matsuyama, Norikazu Isoda, Yoshihiro Sakoda, Takehisa Yamamoto, Kohei Makita
    Transboundary and Emerging Diseases 2023 1 - 15 1865-1674 2023/11/30 
    After 26 years of absence in Japan, a classical swine fever (CSF) outbreak occurred at a domestic pig farm in 2018. Vaccination against the CSF virus with a live attenuated vaccine at pig farms was restarted in October 2019, which was 13 years after the 2006 ban on vaccination. An individual-based simulation model for CSF antibody dynamics was developed to determine an effective CSF vaccination strategy for pig populations. In creating a simulated pig herd, the optimal vaccination age of piglets and the effect of vaccinating piglets twice were evaluated. Additionally, the herd immunity was monitored every 6 months for 4 years after the start of vaccination, and the effects of intensive sow replacement policies were assessed. The simulation results indicated that the vaccination age should be delayed relative to the age used before the 2006 ban on vaccination and shifted earlier, from 8 weeks to 6 weeks, as time elapses. The simulations indicated a tradeoff in protection between the weaning period (i.e., maternally derived antibodies) and the fattening period (i.e., by vaccine-induced antibodies). Mixing sows with high and low antibody titers, particularly sows that received the first vaccination and those born after the start of vaccination, resulted in a high variation in antibody titer among pigs on the farm. This study also clarified the positive effect of intensive sow replacement strategies on shortening the period in which sows show diverse titers. Differences in sow replacement rates among farms and/or the time lag in starting vaccination in different prefectures result in heterogeneity in herd immunity in Japan; thus, herd immunity status should be examined at every farm using this simulation model.
  • Riai Okamoto, Nobumasa Ito, Yutaro Ide, Bouchra Kitab, Yoshihiro Sakoda, Kyoko Tsukiyama-Kohara
    BMC biotechnology 23 (1) 37 - 37 2023/09/08 
    BACKGROUND: Classical swine fever (CSF) is a fatal contagious disease affecting pigs caused by classical swine fever virus (CSFV). The disease can be transmitted by pigs and wild boars, and it is difficult to prevent and control. To obtain necessary information to establish the CSFV resistant animals in a future study, we designed lentiviral vector-delivered short hairpin RNAs (shRNAs) targeting the conserved domain III of the internal ribosomal entry site (IRES) of the CSFV genomic RNA. RESULTS: First, we confirmed the effects of siRNAs on CSFV-IRES activity. We observed significant inhibition of CSFV-IRES activity by si42 (domain IIIa), si107 (domain IIIc), and si198 (domain IIIf) in SK-L cells and si56 (domain IIIb), si142 (domain IIId1) and si198 in HEK293 cells without affecting the amount of luciferase RNA. Next, we constructed lentiviral vectors expressing shRNA based on siRNA sequences. Treatment with shRNA-expressing lentivirus was examined at 7 and 14 days post infection in SK-L cells and HEK293 cells, and CSFV-IRES was significantly suppressed at 14 days (sh42) post infection in HEK293 cells without significant cytotoxicity. Next, we examined the silencing effect of siRNA on CSFV replicon RNA and observed a significant effect by si198 after 2 days of treatment and by shRNA-expressing lentivirus (sh56, sh142, and sh198) infection after 14 days of treatment. Treatment of sh198-expressing lentivirus significantly suppressed CSFV infection at 3 days after infection. CONCLUSION: The IRES targeting sh198 expressing lentivirus vector can be a candidate tool for CSFV infection control.
  • Kei Nabeshima, Yoshihiro Takadate, Kosuke Soda, Takahiro Hiono, Norikazu Isoda, Yoshihiro Sakoda, Junki Mine, Kohtaro Miyazawa, Manabu Onuma, Yuko Uchida
    Viruses 15 (9) 2023/09/01 
    In the fall of 2022, high pathogenicity avian influenza viruses (HPAIVs) were detected from raptors and geese in Japan, a month earlier than in past years, indicating a shift in detection patterns. In this study, we conducted a phylogenetic analysis on H5N1 HPAIVs detected from six wild birds during the 2022/2023 season to determine their genetic origins. Our findings revealed that these HPAIVs belong to the G2 group within clade 2.3.4.4b, with all isolates classified into three subgroups: G2b, G2d, and G2c. The genetic background of the G2b virus (a peregrine falcon-derived strain) and G2d viruses (two raptors and two geese-derived strains) were the same as those detected in Japan in the 2021/2022 season. Since no HPAI cases were reported in Japan during the summer of 2022, it is probable that migratory birds reintroduced the G2b and G2d viruses. Conversely, the G2c virus (a raptor-derived strain) was first recognized in Japan in the fall of 2022. This strain might share a common ancestor with HPAIVs from Asia and West Siberia observed in the 2021/2022 season. The early migration of waterfowl to Japan in the fall of 2022 could have facilitated the early invasion of HPAIVs.
  • Loc Tan Huynh, Norikazu Isoda, Lim Yik Hew, Saho Ogino, Yume Mimura, Maya Kobayashi, Taksoo Kim, Tatsuya Nishi, Katsuhiko Fukai, Takahiro Hiono, Yoshihiro Sakoda
    Viruses 15 (7) 1587 - 1587 2023/07/20 
    A previous study proved that vGPE− mainly maintains the properties of classical swine fever (CSF) virus, which is comparable to the GPE− vaccine seed and is a potentially valuable backbone for developing a CSF marker vaccine. Chimeric viruses were constructed based on an infectious cDNA clone derived from the live attenuated GPE− vaccine strain as novel CSF vaccine candidates that potentially meet the concept of differentiating infected from vaccinated animals (DIVA) by substituting the glycoprotein Erns of the GPE− vaccine strain with the corresponding region of non-CSF pestiviruses, either pronghorn antelope pestivirus (PAPeV) or Phocoena pestivirus (PhoPeV). High viral growth and genetic stability after serial passages of the chimeric viruses, namely vGPE−/PAPeV Erns and vGPE−/PhoPeV Erns, were confirmed in vitro. In vivo investigation revealed that two chimeric viruses had comparable immunogenicity and safety profiles to the vGPE− vaccine strain. Vaccination at a dose of 104.0 TCID50 with either vGPE−/PAPeV Erns or vGPE−/PhoPeV Erns conferred complete protection for pigs against the CSF virus challenge in the early stage of immunization. In conclusion, the characteristics of vGPE−/PAPeV Erns and vGPE−/PhoPeV Erns affirmed their properties, as the vGPE− vaccine strain, positioning them as ideal candidates for future development of a CSF marker vaccine.
  • Annie Kalonda, Ngonda Saasa, Masahiro Kajihara, Naganori Nao, Ladislav Moonga, Joseph Ndebe, Akina Mori-Kajihara, Andrew Nalishuwa Mukubesa, Mulemba Samutela, Samuel Munjita, Yoshihiro Sakoda, Hirofumi Sawa, Ayato Takada, Edgar Simulundu
    Transboundary and Emerging Diseases 2023 1 - 16 1865-1674 2023/03/01 
    In recent years, the southern African region has experienced repeated incursions of highly pathogenic avian influenza viruses (HPAIVs), with wild migratory birds being implicated in the spread. To understand the profile of avian influenza viruses (AIVs) circulating in Zambia, we surveyed wild waterfowl for AIVs and phylogenetically characterised the isolates detected in 2015, 2020, and 2021. A total of 2,851 faecal samples of wild waterfowl were collected from Lochinvar National Park in the Southern Province of Zambia. During the study period, 85 (3.0%) low pathogenicity AIVs belonging to various subtypes were isolated, with H2N9, H8N4, and H10N8 being reported for the first time in avian species in Africa. The majority of the isolates were detected from glossy ibis (order Pelecaniformes) making it the first report of AIV from these birds in Zambia. Phylogenetic analysis of all eight gene segments of the 30 full genomes obtained in this study revealed that all the isolates belonged to the Eurasian lineage with their closest relatives being viruses isolated from wild and/or domestic birds in Bangladesh, Belgium, Egypt, Georgia, Mongolia, the Netherlands, and South Africa. Additionally, the Zambian viruses were grouped into distinct clusters based on the year of isolation. While no notifiable AIVs of the H5 or H7 subtypes were detected in wild birds in Zambia, viral internal protein genes of some viruses were closely related to H7 low pathogenicity AIVs. This study shows that periodically, a considerable diversity of AIV subtypes are introduced into the Zambian ecosystem by wild migratory waterfowl. The findings highlight the importance of continuous surveillance and monitoring of AIVs in wild waterfowl, including birds traditionally not considered to be major AIV reservoirs, for a better understanding of the eco-epidemiology and evolutionary dynamics of AIVs in Africa.
  • Yuta Tsukamoto, Takahiro Hiono, Shintaro Yamada, Keita Matsuno, Aileen Faist, Tobias Claff, Jianyu Hou, Vigneshwaran Namasivayam, Anja Vom Hemdt, Satoko Sugimoto, Jin Ying Ng, Maria H Christensen, Yonas M Tesfamariam, Steven Wolter, Stefan Juranek, Thomas Zillinger, Stefan Bauer, Takatsugu Hirokawa, Florian I Schmidt, Georg Kochs, Masayuki Shimojima, Yi-Shuian Huang, Andreas Pichlmair, Beate M Kümmerer, Yoshihiro Sakoda, Martin Schlee, Linda Brunotte, Christa E Müller, Manabu Igarashi, Hiroki Kato
    Science (New York, N.Y.) 379 (6632) 586 - 591 2023/02/10 
    Orthomyxo- and bunyaviruses steal the 5' cap portion of host RNAs to prime their own transcription in a process called "cap snatching." We report that RNA modification of the cap portion by host 2'-O-ribose methyltransferase 1 (MTr1) is essential for the initiation of influenza A and B virus replication, but not for other cap-snatching viruses. We identified with in silico compound screening and functional analysis a derivative of a natural product from Streptomyces, called trifluoromethyl-tubercidin (TFMT), that inhibits MTr1 through interaction at its S-adenosyl-l-methionine binding pocket to restrict influenza virus replication. Mechanistically, TFMT impairs the association of host cap RNAs with the viral polymerase basic protein 2 subunit in human lung explants and in vivo in mice. TFMT acts synergistically with approved anti-influenza drugs.
  • Kien Trung Le, Lam Thanh Nguyen, Loc Tan Huynh, Duc-Huy Chu, Long Van Nguyen, Tien Ngoc Nguyen, Tien Ngoc Tien, Keita Matsuno, Masatoshi Okamatsu, Takahiro Hiono, Norikazu Isoda, Yoshihiro Sakoda
    Microorganisms 11 (2) 2023/01/18 
    The H9 and H6 subtypes of low pathogenicity avian influenza viruses (LPAIVs) cause substantial economic losses in poultry worldwide, including Vietnam. Herein, we characterized Vietnamese H9 and H6 LPAIVs to facilitate the control of avian influenza. The space-time representative viruses of each subtype were selected based on active surveillance from 2014 to 2018 in Vietnam. Phylogenetic analysis using hemagglutinin genes revealed that 54 H9 and 48 H6 Vietnamese LPAIVs were classified into the sublineages Y280/BJ94 and Group II, respectively. Gene constellation analysis indicated that 6 and 19 genotypes of the H9 and H6 subtypes, respectively, belonged to the representative viruses. The Vietnamese viruses are genetically related to the previous isolates and those in neighboring countries, indicating their circulation in poultry after being introduced into Vietnam. The antigenicity of these subtypes was different from that of viruses isolated from wild birds. Antigenicity was more conserved in the H9 viruses than in the H6 viruses. Furthermore, a representative H9 LPAIV exhibited systemic replication in chickens, which was enhanced by coinfection with avian pathogenic Escherichia coli O2. Although H9 and H6 were classified as LPAIVs, their characterization indicated that their silent spread might significantly affect the poultry industry.
  • Kosuke SODA, Yukiko TOMIOKA, Tatsufumi USUI, Hiroichi OZAKI, Hiroshi ITO, Yasuko NAGAI, Naoki YAMAMOTO, Masatoshi OKAMATSU, Norikazu ISODA, Masahiro KAJIHARA, Yoshihiro SAKODA, Ayato TAKADA, Toshihiro ITO
    Journal of Veterinary Medical Science 85 (9) 942 - 949 0916-7250 2023
  • Keisuke KUWATA, Makoto UKITA, Satoru KATO, Naotoshi KUNINAGA, Eiji TANAKA, Yoshihiro SAKODA, Kohei MAKITA
    Journal of the Japan Veterinary Medical Association (公社)日本獣医師会 76 (11) e274 - e282 0446-6454 2023 
    2018年9月,岐阜県の養豚場で国内26年ぶりの豚熱が発生し,翌年10月から発生予防のためのワクチン接種と抗体検査による免疫状況確認が開始された.免疫状況の評価から,母豚群の免疫抗体価の条件により農場群ごとに接種日齢を調整する必要性が指摘された.そこで母豚とその産子の抗体調査を実施し,移行抗体とワクチンテイクの関係を解析することで,農場ごとのワクチン接種適齢期を推定するシミュレーションモデルを構築した.モデルは母豚のELISA S/P値を用いた産子への移行抗体付与,移行抗体減少,ワクチン免疫付与の予測から構成した.実際の農場のデータを用いて本モデルの予測精度を検証したところ,接種適齢期の推定に利用可能な精度であると考えられた.本手法はワクチン接種適齢期を簡便に推定できるモデルで,豚熱の発生防止に役立つと期待される.(著者抄録)
  • Takahiro Hiono, Daiki Kobayashi, Atsushi Kobayashi, Tamami Suzuki, Yuki Satake, Rio Harada, Keita Matsuno, Mariko Sashika, Hinako Ban, Maya Kobayashi, Keisuke Aoshima, Fumihito Takaya, Hiroko Fujita, Norikazu Isoda, Takashi Kimura, Yoshihiro Sakoda
    Virology 578 35 - 44 2023/01 [Refereed][Not invited]
     
    In winter/spring 2021-2022, high pathogenicity avian influenza viruses (HPAIVs) that are genetically closely related to each other were detected worldwide. In a public garden in Sapporo, Hokkaido, Japan, a crow die-off by HPAIV infection occurred from March 29 to May 18, 2022. During the event, H5N1 HPAIVs were isolated from an Ezo red fox (Vulpes vulpes schrencki) and a tanuki (Nyctereutes procyonoides albus) found in the same garden. The fox showed viral meningoencephalitis and moderate virus replication in the upper respiratory tract, whereas the tanuki showed viral conjunctivitis and secondary bacterial infection in the eyes accompanied with visceral larva migrans. Viruses isolated from the fox and the tanuki were genetically closely related to those isolated from crows in the same garden. Various α2-3 sialosides were found in the respiratory tracts of these canid mammals, consistent with HPAIV infections in these animals. This study highlighted the importance of monitoring HPAIV infections in wild carnivore mammals to detect the potential virus spreading in nature.
  • Yoshikazu Fujimoto, Kohei Ogasawara, Norikazu Isoda, Hitoshi Hatai, Kosuke Okuya, Yukiko Watanabe, Ayato Takada, Yoshihiro Sakoda, Keisuke Saito, Makoto Ozawa
    Frontiers in Microbiology 13 2022/10/03 
    White-tailed sea eagle (Haliaeetus albicilla), a regionally rare species of raptor, is threatened in several countries. To assess the risk of H5 high pathogenicity avian influenza (HPAI) viral infection in rare bird species, we performed experimental infections with a GS/GD96-lineage H5N6 HPAI virus of clade 2.3.4.4e in white-tailed sea eagles. Additionally, during the winter of 2020–2021 in Japan, we accidentally encountered a white-tailed sea eagle that had a fatal outcome due to natural infection with a GS/GD96-lineage H5N8 HPAI virus of clade 2.3.4.4b, allowing us to compare experimental and natural infections in the same rare raptor species. Our experiments demonstrated the susceptibility of white-tailed sea eagles to the GS/GD96-lineage H5 HPAI virus with efficient replication in systemic organs. The potential for the viruses to spread within the white-tailed sea eagle population through indirect transmission was also confirmed. Comprehensive comparisons of both viral distribution and histopathological observations between experimentally and naturally infected white-tailed sea eagles imply that viral replication in the brain is responsible for the disease severity and mortality in this species. These findings provide novel insights into the risk assessment of H5 HPAI viral infection in white-tailed sea eagles, proper diagnostic procedures, potential risks to artificially fed eagle populations and persons handling superficially healthy eagles, potential impact of intragastric infection on eagle outcomes, and possibility of severity of the disease being attributed to viral replication in the brain.
  • Yuji Fujii, Tatsunori Masatani, Shoko Nishiyama, Misuzu Okajima, Fumiki Izumi, Katsunori Okazaki, Yoshihiro Sakoda, Ayato Takada, Makoto Ozawa, Makoto Sugiyama, Naoto Ito
    The Journal of general virology 103 (10) 2022/10 
    A recent study demonstrated the possibility that migratory birds are responsible for the global spread of avian rotavirus A (RVA). However, little is known about what types of RVAs are retained in migratory birds. In this study, to obtain information on RVA strains in migratory birds, we characterised an RVA strain, Ho374, that was detected in a faecal sample from a gull species (Larus sp.). Genetic analysis revealed that all 11 genes of this strain were classified as new genotypes (G28-P[39]-I21-R14-C14-M13-A24-N14-T16-E21-H16). This clearly indicates that the genetic diversity of avian RVAs is greater than previously recognised. Our findings highlight the need for investigations of RVA strains retained in migratory birds, including gulls.
  • Norikazu Isoda, Manabu Onuma, Takahiro Hiono, Ivan Sobolev, Hew Yik Lim, Kei Nabeshima, Hisako Honjyo, Misako Yokoyama, Alexander Shestopalov, Yoshihiro Sakoda
    Viruses 14 (10) 2022/09/30 
    Many high pathogenicity avian influenza (HPAI) cases in wild birds due to H5N1 HPAI virus (HPAIV) infection were reported in northern Japan in the winter of 2021-2022. To investigate the epidemiology of HPAIVs brought to Japan from surrounding areas, a genetic analysis of H5 HPAIVs isolated in northern Japan was performed, and the pathogenicity of the HPAIV in chickens was assessed by experimental infection. Based on the genetic analysis of the hemagglutinin gene, pathogenic viruses detected in northern Japan as well as one in Sakhalin, the eastern part of Russia, were classified into the same subgroup as viruses prevalent in Europe in the same season but distinct from those circulating in Asia in winter 2020-2021. High identities of all eight segment sequences of A/crow/Hokkaido/0103B065/2022 (H5N1) (Crow/Hok), the representative isolates in northern Japan in 2022, to European isolates in the same season could also certify the unlikeliness of causing gene reassortment between H5 HPAIVs and viruses locally circulating in Asia. According to intranasal challenge results in six-week-old chickens, 50% of the chicken-lethal dose of Crow/Hok was calculated as 104.5 times of the 50% egg-infectious dose. These results demonstrated that the currently prevalent H5 HPAIVs could spread widely from certain origins throughout the Eurasian continent, including Europe and the Far East, and implied a possibility that contagious viruses are gathered in lakes in the northern territory via bird migration. Active monitoring of wild birds at the global level is essential to estimate the geographical source and spread dynamics of HPAIVs.
  • Shinsuke Toba, Akihiko Sato, Makoto Kawai, Yoshiyuki Taoda, Yuto Unoh, Shinji Kusakabe, Haruaki Nobori, Shota Uehara, Kentaro Uemura, Keiichi Taniguchi, Masanori Kobayashi, Takeshi Noshi, Ryu Yoshida, Akira Naito, Takao Shishido, Junki Maruyama, Slobodan Paessler, Michael J Carr, William W Hall, Kumiko Yoshimatsu, Jiro Arikawa, Keita Matsuno, Yoshihiro Sakoda, Michihito Sasaki, Yasuko Orba, Hirofumi Sawa, Hiroshi Kida
    Proceedings of the National Academy of Sciences of the United States of America 119 (36) e2206104119  2022/09/06 
    Viral hemorrhagic fevers caused by members of the order Bunyavirales comprise endemic and emerging human infections that are significant public health concerns. Despite the disease severity, there are few therapeutic options available, and therefore effective antiviral drugs are urgently needed to reduce disease burdens. Bunyaviruses, like influenza viruses (IFVs), possess a cap-dependent endonuclease (CEN) that mediates the critical cap-snatching step of viral RNA transcription. We screened compounds from our CEN inhibitor (CENi) library and identified specific structural compounds that are 100 to 1,000 times more active in vitro than ribavirin against bunyaviruses, including Lassa virus, lymphocytic choriomeningitis virus (LCMV), and Junin virus. To investigate their inhibitory mechanism of action, drug-resistant viruses were selected in culture. Whole-genome sequencing revealed that amino acid substitutions in the CEN region of drug-resistant viruses were located in similar positions as those of the CEN α3-helix loop of IFVs derived under drug selection. Thus, our studies suggest that CENi compounds inhibit both bunyavirus and IFV replication in a mechanistically similar manner. Structural analysis revealed that the side chain of the carboxyl group at the seventh position of the main structure of the compound was essential for the high antiviral activity against bunyaviruses. In LCMV-infected mice, the compounds significantly decreased blood viral load, suppressed symptoms such as thrombocytopenia and hepatic dysfunction, and improved survival rates. These data suggest a potential broad-spectrum clinical utility of CENis for the treatment of both severe influenza and hemorrhagic diseases caused by bunyaviruses.
  • Kien Trung LE, Norikazu Isoda, Lam Thanh Nguyen, Duc-Huy Chu, Long Van Nguyen, Minh Quang Phan, Diep Thi Nguyen, Tien Ngoc Nguyen, Tien Ngoc Tien, Tung Thanh LE, Takahiro Hiono, Keita Matsuno, Masatoshi Okamatsu, Yoshihiro Sakoda
    The Journal of veterinary medical science 84 (6) 860 - 868 2022/05/13 
    The impact of low pathogenicity avian influenza (LPAI) has been confirmed mainly in farms. Unlike apparent losses caused by the high pathogenicity avian influenza (HPAI), the LPAI impact has been hardly evaluated due to underestimating its spread and damage. In 2019, a questionnaire study was conducted in southern Vietnam to identify the specific risk factors of LPAI virus (LPAIV) circulation and to find associations between husbandry activities and LPAI prevalence. A multilevel regression analysis indicated that keeping Muscovy ducks during farming contributed to LPAIV positivity [Odds ratio=208.2 (95% confidence interval: 13.4-1.1×104)]. In cluster analysis, farmers willing to report avian influenza (AI) events and who agreed with the local AI control policy had a slightly lower risk for LPAIV infection although there was no significance in the correlation between farmer characteristics and LPAI occurrence. These findings indicated that keeping Muscovy ducks without appropriate countermeasures might increase the risk of LPAIV infection. Furthermore, specific control measures at the local level are effective for LPAIV circulation, and the improvement of knowledge about biosecurity and attitude contributes to reducing LPAI damage.
  • Yutaro Ide, Bouchra Kitab, Nobumasa Ito, Riai Okamoto, Yui Tamura, Takafumi Matsui, Yoshihiro Sakoda, Kyoko Tsukiyama-Kohara
    Scientific reports 12 (1) 6709 - 6709 2022/04/25 
    Foot-and-mouth disease virus (FMDV) and classical swine fever virus (CSFV) possess positive-sense single-stranded RNA genomes and an internal ribosomal entry site (IRES) element within their 5'-untranslated regions. To investigate the common host factors associated with these IRESs, we established cell lines expressing a bicistronic luciferase reporter plasmid containing an FMDV-IRES or CSFV-IRES element between the Renilla and firefly luciferase genes. First, we treated FMDV-IRES cells with the French maritime pine extract, Pycnogenol (PYC), and examined its suppressive effect on FMDV-IRES activity, as PYC has been reported to have antiviral properties. Next, we performed microarray analysis to identify the host factors that modified their expression upon treatment with PYC, and confirmed their function using specific siRNAs. We found that polycystic kidney disease 1-like 3 (PKD1L3) and ubiquitin-specific peptidase 31 (USP31) were associated with FMDV-IRES activity. Moreover, silencing of these factors significantly suppressed CSFV-IRES activity. Thus, PKD1L3 and USP31 are host factors associated with the functions of FMDV- and CSFV-IRES elements.
  • Daiki Kobayashi, Takahiro Hiono, Osamu Ichii, Shoko Nishihara, Sayaka Takase-Yoden, Kazuo Yamamoto, Hiroto Kawashima, Norikazu Isoda, Yoshihiro Sakoda
    Virus research 315 198771 - 198771 2022/04/14 
    Avian influenza viruses (AIVs) circulating in wild ducks are rarely transmitted directly to chickens. Previous studies demonstrated that chickens possess fucosylated and/or sulfated α2,3 sialosides on their tracheal epithelia, whereas intestinal epithelia of ducks express canonical α2,3 sialosides. Turkeys, the third major poultry species in the world, are known to show broad susceptibility to various avian influenza viruses. To elucidate the molecular basis of the broad susceptibility of turkeys to duck and chicken AIVs, we characterized various receptors for AIVs on their tissues. The experimental infection of turkeys demonstrated their dual susceptibility to duck and chicken AIVs. Further, comprehensive histochemical analyses using lectins, anti-glycan antibodies, and recombinant hemagglutinins, combined with glycosidase digestions, identified the presence of fucosylated and/or sulfated in addition to canonical α2,3 sialosides on their respiratory epithelia. The receptor distributions in turkeys were consistent with their dual susceptibility to duck and chicken AIVs. Also, our findings suggested the potential roles of turkeys in interspecies transmission of AIVs from ducks to chickens.
  • Takashi Nakamura, Norikazu Isoda, Yoshihiro Sakoda, Hideyoshi Harashima
    Journal of controlled release : official journal of the Controlled Release Society 343 361 - 378 2022/02/03 [Refereed]
     
    Respiratory viruses have sometimes resulted in worldwide pandemics, with the influenza virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) being major participants. Long-term efforts have made it possible to control the influenza virus, but seasonal influenza continues to take many lives each year, and a pandemic influenza virus sometimes emerges. Although vaccines for coronavirus disease 2019 (COVID-19) have been developed, we are not yet able to coexist with the SARS-CoV-2. To overcome such viruses, it is necessary to obtain knowledge about international surveillance systems, virology, ecology and to determine that immune responses are effective. The information must then be transferred to drugs. Delivery systems would be expected to contribute to the rational development of drugs. In this review, virologist and drug delivery system (DDS) researchers discuss drug delivery strategies, especially the use of lipid-based nanocarriers, for fighting to respiratory virus infections.
  • Shizuka Hirose, Norikazu Isoda, Loc Tan Huynh, Taksoo Kim, Keiichiro Yoshimoto, Tohru Tanaka, Kenjiro Inui, Takahiro Hiono, Yoshihiro Sakoda
    Pathogens (Basel, Switzerland) 11 (2) 2022/01/27 
    The inhibitory effects of 5-aminolevulinic acid phosphate (5-ALA), an important amino acid for energy production in the host, against viral infections were previously reported. Here, the antiviral effects of 5-ALA against classical swine fever virus (CSFV) belonging to the genus Pestivirus in the Flaviviridae family and its possible mechanisms were investigated. CSFV replication was suppressed in swine cells supplemented with 5-ALA or its metabolite, protoporphyrin IX (PPIX). The infectivity titer of CSFV was decreased after mixing with PPIX extracellularly. In addition, the activities of the replication cycle were decreased in the presence of PPIX based on the CSFV replicon assay. These results showed that PPIX exerted antiviral effects by inactivating virus particles and inhibiting the replication cycle. To evaluate the in vivo efficacy of 5-ALA, pigs were supplemented daily with 5-ALA for 1 week before virus inoculation and then inoculated with a virulent CSFV strain at the 107.0 50% tissue culture infectious dose. The clinical scores of the supplemented group were significantly lower than those of the nonsupplemented group, whereas the virus growth was not. Taken together, 5-ALA showed antiviral effects against CSFV in vitro, and PPIX played a key role by inactivating virus particles extracellularly and inhibiting the replication cycle intracellularly.
  • Kosuke Soda, Yukiko Tomioka, Tatsufumi Usui, Yukiko Uno, Yasuko Nagai, Hiroshi Ito, Takahiro Hiono, Tomokazu Tamura, Masatoshi Okamatsu, Masahiro Kajihara, Naganori Nao, Yoshihiro Sakoda, Ayato Takada, Toshihiro Ito
    Avian pathology : journal of the W.V.P.A 51 (2) 1 - 8 2022/01/25 
    The pathogenicity of the H5 subtype high pathogenicity avian influenza viruses (HPAIVs) in Ardeidae bird species has not been investigated yet, despite the increasing infections reported. Therefore, the present study aimed to examine the susceptibility of the Ardeidae species, which had already been reported to be susceptible to HPAIVs, to a clade 2.3.2.1 H5N1 HPAIV. Juvenile herons (four grey herons, one intermediate egret, two little egrets, and three black-crowned night herons) were intranasally inoculated with 106 50% egg infectious dose of the virus and observed for 10 days. Two of the four grey herons showed lethargy and conjunctivitis; among them, one died at 6 days post-inoculation (dpi). The viruses were transmitted to the other two cohoused naïve grey herons. Some little egrets and black-crowned night herons showing neurological disorders died at 4-5 dpi; these birds mainly shed the virus via the oral route. The viruses predominantly replicated in the brains of birds that died of infection. Seroconversion was observed in most surviving birds, except some black-crowned night herons. These results demonstrate that most Ardeidae species are susceptible to H5 HPAIVs, sometimes with lethal effects. Herons are mostly colonial and often share habitats with Anseriformes, natural hosts of influenza A viruses; therefore, the risks of cluster infection and contribution to viral dissemination should be continuously evaluated. RESEARCH HIGHLIGHTSClade 2.3.2.1 H5N1 HPAIV causes lethal infections in Ardeidae sp.Viruses are transmitted among grey herons.Some herons with HPAIV showed conjunctivitis or neurological symptoms.HPAIV systemically replicated in herons tissues.
  • Cindy M Spruit, Xueyong Zhu, Ilhan Tomris, María Ríos Carrasco, Alvin X Han, Frederik Broszeit, Roosmarijn van der Woude, Kim M Bouwman, Michel M T Luu, Keita Matsuno, Yoshihiro Sakoda, Colin A Russell, Ian A Wilson, Geert-Jan Boons, Robert P de Vries
    Journal of virology 96 (5) jvi0212021  2022/01/19 
    Influenza A viruses (IAV) initiate infection by binding to glycans with terminal sialic acids on the cell surface. Hosts of IAV variably express two major forms of sialic acid, N-acetylneuraminic acid (NeuAc) and N-glycolylneuraminic acid (NeuGc). NeuGc is produced in most mammals including horses and pigs, but is absent in humans, ferrets, and birds. The only known naturally occurring IAVs that exclusively bind NeuGc are extinct highly pathogenic equine H7N7 viruses. We determined the crystal structure of a representative equine H7 hemagglutinin (HA) in complex with NeuGc and observed high similarity in the receptor-binding domain with an avian H7 HA. To determine the molecular basis for NeuAc and NeuGc specificity, we performed systematic mutational analyses, based on the structural insights, on two distant avian H7 HAs and an H15 HA. We found that mutation A135E is key for binding α2,3-linked NeuGc but does not abolish NeuAc binding. Additional mutations S128T, I130V, T189A, and K193R converted the specificity from NeuAc to NeuGc. We investigated the residues at positions 128, 130, 135, 189, and 193 in a phylogenetic analysis of avian and equine H7 HAs. This revealed a clear distinction between equine and avian residues. The highest variability was observed at key position 135, of which only the equine glutamic acid led to NeuGc binding. These results demonstrate that genetically distinct H7 and H15 HAs can be switched from NeuAc to NeuGc binding and vice versa after introduction of several mutations, providing insights into the adaptation of H7 viruses to NeuGc receptors. (250 words) Importance Influenza A viruses cause millions of cases of severe illness and deaths annually. To initiate infection and replicate, the virus first needs to bind to a structure on the cell surface, like a key fitting in a lock. For influenza A viruses, these 'keys' (receptors) on the cell surface are chains of sugar molecules (glycans). The terminal sugar on these glycans is often either N-acetylneuraminic acid (NeuAc) or N-glycolylneuraminic acid (NeuGc). Most influenza A viruses bind NeuAc, but a small minority binds NeuGc. NeuGc is present in species like horses, pigs, and mice, but not in humans, ferrets, and birds. Here, we investigated the molecular determinants of NeuGc specificity and the origin of viruses that bind NeuGc.
  • Keiichi Taniguchi, Yoshinori Ando, Masanori Kobayashi, Shinsuke Toba, Haruaki Nobori, Takao Sanaki, Takeshi Noshi, Makoto Kawai, Ryu Yoshida, Akihiko Sato, Takao Shishido, Akira Naito, Keita Matsuno, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida
    Viruses 14 (1) 2022/01/08 
    Human infections caused by the H5 highly pathogenic avian influenza virus (HPAIV) sporadically threaten public health. The susceptibility of HPAIVs to baloxavir acid (BXA), a new class of inhibitors for the influenza virus cap-dependent endonuclease, has been confirmed in vitro, but it has not yet been fully characterized. Here, the efficacy of BXA against HPAIVs, including recent H5N8 variants, was assessed in vitro. The antiviral efficacy of baloxavir marboxil (BXM) in H5N1 virus-infected mice was also investigated. BXA exhibited similar in vitro activities against H5N1, H5N6, and H5N8 variants tested in comparison with seasonal and other zoonotic strains. Compared with oseltamivir phosphate (OSP), BXM monotherapy in mice infected with the H5N1 HPAIV clinical isolate, the A/Hong Kong/483/1997 strain, also caused a significant reduction in viral titers in the lungs, brains, and kidneys, thereby preventing acute lung inflammation and reducing mortality. Furthermore, compared with BXM or OSP monotherapy, combination treatments with BXM and OSP using a 48-h delayed treatment model showed a more potent effect on viral replication in the organs, accompanied by improved survival. In conclusion, BXM has a potent antiviral efficacy against H5 HPAIV infections.
  • Asami Nishimori, Shizuka Hirose, Saho Ogino, Kiyohiko Andoh, Norikazu Isoda, Yoshihiro Sakoda
    The Journal of veterinary medical science 84 (2) 228 - 232 2021/12/14 
    Bovine viral diarrhea virus (BVDV) is a causative agent of bovine viral diarrhea. In Japan, a previous study reported that subgenotype 1b viruses were predominant until 2014. Because there is little information regarding the recent epidemiological status of BVDV circulating in Japan, we performed genetic characterization of 909 BVDV isolates obtained between 2014 and 2020. We found that 657 and 252 isolates were classified as BVDV-1 and BVDV-2, respectively, and that they were further subdivided into 1a (35 isolates, 3.9%), 1b (588, 64.7%), 1c (34, 3.7%), and 2a (252, 27.7%). Phylogenetic analysis using entire E2 coding sequence revealed that a major domestic cluster in Japan among BVDV-1b and 2a viruses were unchanged from a previous study conducted from 2006 to 2014. These results provide updated information concerning the epidemic strain of BVDV in Japan, which would be helpful for appropriate vaccine selection.
  • Kosuke Soda, Hiroichi Ozaki, Hiroshi Ito, Tatsufumi Usui, Masatoshi Okamatsu, Keita Matsuno, Yoshihiro Sakoda, Tsuyoshi Yamaguchi, Toshihiro Ito
    The Journal of veterinary medical science 83 (12) 1891 - 1898 2021/12/02 
    Large highly pathogenic avian influenza (HPAI) outbreaks caused by clade 2.3.4.4e H5N6 viruses occurred in Japan during the 2016-2017 winter. To date, several reports regarding these outbreaks have been published, however a comprehensive study including geographical and time course validations has not been performed. Herein, 58 Japanese HPAI virus (HPAIV) isolates from the 2016-2017 season were added for phylogenetic analyses and the antigenic relationships among the causal viruses were elucidated. The locations where HPAIVs were found in the early phase of the outbreaks were clustered into three regions. Genotypes C1, C5, and C6-8 HPAIVs were found in specific areas. Two strains had phylogenetically distinct hemagglutinin (HA) and non-structural (NS) genes from other previously identified strains, respectively. The estimated latest divergence date between the viral genotypes suggests that genetic reassortment occurred in bird populations before their winter migration to Japan. Antigenic differences in 2016-2017 HPAIVs were not observed, suggesting that antibody pressure in the birds did not contribute to the selection of HPAIV genotypes. In the late phase, the majority of HPAI cases in wild birds occurred south of the lake freezing line. At the end of the outbreak, HPAI re-occurred in East coast region, which may be due to the spring migration route of Anas bird species. These trends were similar to those observed in the 2010-2011 outbreaks, suggesting there is a typical pattern of seeding and dissemination of HPAIV in Japan.
  • Kien Trung Le, Mark A Stevenson, Norikazu Isoda, Lam Thanh Nguyen, Duc-Huy Chu, Tien Ngoc Nguyen, Long Van Nguyen, Tien Ngoc Tien, Tung Thanh Le, Keita Matsuno, Masatoshi Okamatsu, Yoshihiro Sakoda
    Transboundary and emerging diseases 2021/11/04 
    In South Vietnam, live bird markets (LBMs) are key in the value chain of poultry products and spread of avian influenza virus (AIV) although they may not be the sole determinant of AIV prevalence. For this reason, a risk analysis of AIV prevalence was conducted accounting for all value chain factors. A cross-sectional study of poultry flock managers and poultry on backyard farms, commercial (high biosecurity) farms, LBMs and poultry delivery stations (PDSs) in four districts of Vinh Long province was conducted between December 2016 and August 2017. A total of 3597 swab samples were collected from birds from 101 backyard farms, 50 commercial farms, 58 sellers in LBMs and 19 traders in PDSs. Swab samples were submitted for AIV isolation. At the same time a questionnaire was administered to flock managers asking them to provide details of their knowledge, attitude and practices related to avian influenza. Multiple correspondence analysis and a mixed-effects multivariable logistic regression model were developed to identify enterprise and flock manager characteristics that increased the risk of AIV positivity. A total of 274 birds were positive for AIV isolation, returning an estimated true prevalence of 7.6% [95% confidence interval (CI): 6.8%-8.5%]. The odds of a bird being AIV positive if it was from an LBM or PDS were 45 (95% CI: 3.4-590) and 25 (95% CI: 1.4-460), respectively, times higher to the odds of a bird from a commercial poultry farm being AIV positive. The odds of birds being AIV positive for respondents with a mixed (uncertain or inconsistent) level and a low level of knowledge about AI were 5.0 (95% CI: 0.20-130) and 3.5 (95% CI: 0.2-62), respectively, times higher to the odd of birds being positive for respondents with a good knowledge of AI. LBMs and PDSs should receive specific emphasis in AI control programs in Vietnam. Our findings provide evidence to support the hypothesis that incomplete respondent knowledge of AI and AIV spread mechanism were associated with an increased risk of AIV positivity. Delivery of education programs specifically designed for those in each enterprise will assist in this regard. The timing and frequency of delivery of education programs are likely to be important if the turnover of those working in LBMs and PDSs is high.
  • Hayato Harima, Kosuke Okuya, Masahiro Kajihara, Hirohito Ogawa, Edgar Simulundu, Eugene Bwalya, Yongjin Qiu, Akina Mori-Kajihara, Musso Munyeme, Yoshihiro Sakoda, Takehiko Saito, Bernard M Hang'ombe, Hirofumi Sawa, Aaron S Mweene, Ayato Takada
    Transboundary and emerging diseases 69 (4) e931-e943  2021/11/01 
    Influenza A viruses (IAVs) cause highly contagious respiratory diseases in humans and animals. In 2009, a swine-origin pandemic H1N1 IAV, designated A(H1N1)pdm09 virus, spread worldwide, and has since frequently been introduced into pig populations. Since novel reassortant IAVs with pandemic potential may emerge in pigs, surveillance for IAV in pigs is therefore necessary not only for the pig industry but also for public health. However, epidemiological information on IAV infection of pigs in Africa remains sparse. In this study, we collected 246 serum and 605 nasal swab samples from pigs in Zambia during the years 2011-2018. Serological analyses revealed that 49% and 32% of the sera collected in 2011 were positive for hemagglutination-inhibition (HI) and neutralizing antibodies against A(H1N1)pdm09 virus, respectively, whereas less than 5.3% of sera collected during the following period (2012-2018) were positive in both serological tests. The positive rate and the neutralization titres to A(H1N1)pdm09 virus were higher than those to classical swine H1N1 and H1N2 IAVs. On the other hand, the positive rate for swine H3N2 IAV was very low in the pig population in Zambia in 2011-2018 (5.3% and 0% in HI and neutralization tests, respectively). From nasal swab samples, we isolated one H3N2 and eight H1N1 IAV strains with an isolation rate of 1.5%. Phylogenetic analyses of all eight gene segments revealed that the isolated IAVs were closely related to human IAV strains belonging to A(H1N1)pdm09 and seasonal H3N2 lineages. Our findings indicate that reverse zoonotic transmission from humans to pigs occurred during the study period in Zambia and highlight the need for continued surveillance to monitor the status of IAVs circulating in swine populations in Africa.
  • Enkhbold Bazarragchaa, Takahiro Hiono, Norikazu Isoda, Hirotaka Hayashi, Masatoshi Okamatsu, Yoshihiro Sakoda
    The Journal of veterinary medical science 83 (11) 1694 - 1701 2021/10/31 
    Sporadic spreads of swine-origin influenza H3N2 variant (H3N2v) viruses were reported in humans, resulting in 437 human infections between 2011 and 2021 in the USA. Thus, an effective vaccine is needed to better control a potential pandemic for these antigenically distinct viruses from seasonal influenza. In this study, a candidate vaccine strain with efficient growth capacity in chicken embryos was established through serial blind passaging of A/Indiana/08/2011 (H3N2)v in mice and chicken embryos. Seven amino acid substitutions (M21I in PA; A138T, N165K, and V226A in HA; S312L in NP; T167I in M1; G62A in NS1 proteins) were found in the passaged viruses without a major change in the antigenicity. This mouse- and egg-adapted virus was used as a vaccine and challenge strain in mice to evaluate the efficacy of the H3N2v vaccine in different doses. Antibodies with high neutralizing titers were induced in mice immunized with 100 µg of inactivated whole-virus particles, and those mice were significantly protected from the challenge of homologous strain. The findings indicated that the established strain in the study was useful for vaccine study in mouse models.
  • Tomomi Ichimiya, Masatoshi Okamatsu, Takaaki Kinoshita, Daiki Kobayashi, Osamu Ichii, Naoki Yamamoto, Yoshihiro Sakoda, Hiroshi Kida, Hiroto Kawashima, Kazuo Yamamoto, Sayaka Takase-Yoden, Shoko Nishihara
    Virology 562 29 - 39 2021/10 [Refereed]
     
    When human influenza viruses are isolated and passaged in chicken embryos, variants with amino acid substitutions around the receptor binding site of hemagglutinin (HA) are selected; however, the mechanisms that underlie this phenomenon have yet to be elucidated. Here, we analyzed the receptor structures that contributed to propagation of egg-passaged human H1N1 viruses. The analysis included seasonal and 2009 pandemic strains, both of which have amino acid substitutions of HA found in strains isolated or passaged in eggs. These viruses exhibited high binding to sulfated glycans containing NeuAcα2-3Gal. In MDCK cells overexpressing the sulfotransferase that synthesize Galβ1-4(SO3--6)GlcNAc, production of human H1N1 viruses was increased up to 90-fold. Furthermore, these sulfated glycans were expressed on the allantoic and amniotic membranes of chicken embryos. These results suggest that 6-sulfo sialyl Lewis X and/or NeuAcα2-3Galβ1-4(SO3--6)GlcNAc are involved in efficient propagation of human H1N1 viruses in chicken embryos.
  • Fumihiro Kodama, Hiroki Yamaguchi, Eunsil Park, Kango Tatemoto, Mariko Sashika, Ryo Nakao, Yurino Terauchi, Keita Mizuma, Yasuko Orba, Hiroaki Kariwa, Katsuro Hagiwara, Katsunori Okazaki, Akiko Goto, Rika Komagome, Masahiro Miyoshi, Takuya Ito, Kimiaki Yamano, Kentaro Yoshii, Chiaki Funaki, Mariko Ishizuka, Asako Shigeno, Yukari Itakura, Lesley Bell-Sakyi, Shunji Edagawa, Atsushi Nagasaka, Yoshihiro Sakoda, Hirofumi Sawa, Ken Maeda, Masayuki Saijo, Keita Matsuno
    Nature communications 12 (1) 5539 - 5539 2021/09/20 
    The increasing burden of tick-borne orthonairovirus infections, such as Crimean-Congo hemorrhagic fever, is becoming a global concern for public health. In the present study, we identify a novel orthonairovirus, designated Yezo virus (YEZV), from two patients showing acute febrile illness with thrombocytopenia and leukopenia after tick bite in Hokkaido, Japan, in 2019 and 2020, respectively. YEZV is phylogenetically grouped with Sulina virus detected in Ixodes ricinus ticks in Romania. YEZV infection has been confirmed in seven patients from 2014-2020, four of whom were co-infected with Borrelia spp. Antibodies to YEZV are found in wild deer and raccoons, and YEZV RNAs have been detected in ticks from Hokkaido. In this work, we demonstrate that YEZV is highly likely to be the causative pathogen of febrile illness, representing the first report of an endemic infection associated with an orthonairovirus potentially transmitted by ticks in Japan.
  • 北海道の野鳥から検出されたロタウイルスA JC-105株の遺伝学的解析
    藤井 祐至, 正谷 達謄, 西山 祥子, 藤原 拓朗, 迫田 義博, 高田 礼人, 小澤 真, 杉山 誠, 伊藤 直人
    日本獣医学会学術集会講演要旨集 (公社)日本獣医学会 164回 [FO - 1] 1347-8621 2021/09
  • Taksoo Kim, Loc Tan Huynh, Shizuka Hirose, Manabu Igarashi, Takahiro Hiono, Norikazu Isoda, Yoshihiro Sakoda
    Viruses 13 (8) 2021/08/23 [Refereed]
     
    The GPE- strain is a live attenuated vaccine for classical swine fever (CSF) developed in Japan. In the context of increasing attention for the differentiating infected from vaccinated animals (DIVA) concept, the achievement of CSF eradication with the GPE- proposes it as a preferable backbone for a recombinant CSF marker vaccine. While its infectious cDNA clone, vGPE-, is well characterized, 10 amino acid substitutions were recognized in the genome, compared to the original GPE- vaccine seed. To clarify the GPE- seed availability, this study aimed to generate and characterize a clone possessing the identical amino acid sequence to the GPE- seed. The attempt resulted in the loss of the infectious GPE- seed clone production due to the impaired replication by an amino acid substitution in the viral polymerase NS5B. Accordingly, replication-competent GPE- seed variant clones were produced. Although they were mostly restricted to propagate in the tonsils of pigs, similarly to vGPE-, their type I interferon-inducing capacity was significantly lower than that of vGPE-. Taken together, vGPE- mainly retains ideal properties for the CSF vaccine, compared with the seed variants, and is probably useful in the development of a CSF marker vaccine.
  • Shizuka Hirose, Kosuke Notsu, Satoshi Ito, Yoshihiro Sakoda, Norikazu Isoda
    Pathogens (Basel, Switzerland) 10 (8) 2021/07/21 [Refereed]
     
    Bovine viral diarrhea (BVD) caused by BVD virus (BVDV) leads to economic loss worldwide. Cattle that are persistently infected (PI) with BVDV are known to play an important role in viral transmission in association with the animal movement, as they shed the virus during their lifetime. In this research, the "hot spot" for BVD transmission was estimated by combining phylogenetic and epidemiological analyses for PI cattle and cattle that lived together on BVDV affected farms in Tokachi district, Hokkaido prefecture, Japan. Viral isolates were genetically categorized into BVDV-1a, 1b, and 2a, based on the nucleotide sequence of the entire E2 region. In BVDV genotype 1, subgenotype b (BVDV-1b), cluster I was identified as the majority in Tokachi district. Network analysis indicated that 12 of the 15 affected farms had cattle movements from other facilities (PI-network) and farms affected with BVDV-1b cluster I consisted of a large network. It was implied that the number of cattle movements themselves would be a risk of BVD transmission, using the PageRank algorithm. Therefore, these results demonstrate that cattle movements would contribute to disease spread and the combination of virological and epidemiological analysis methods would be beneficial in determining possible virus transmission routes.
  • Mutsuo Yamaya, Yoshitaka Shimotai, Ayako Ohkawara, Enkhbold Bazarragchaa, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida, Hidekazu Nishimura
    Journal of medical virology 93 (6) 3484 - 3495 2021/06 [Refereed]
     
    The effects of the clinically used protease inhibitor nafamostat on influenza virus replication have not been well studied. Primary human tracheal (HTE) and nasal (HNE) epithelial cells were pretreated with nafamostat and infected with the 2009 pandemic [A/Sendai-H/108/2009/(H1N1) pdm09] or seasonal [A/New York/55/2004(H3N2)] influenza virus. Pretreatment with nafamostat reduced the titers of the pandemic and seasonal influenza viruses and the secretion of inflammatory cytokines, including interleukin-6 and tumor necrosis factor-α, in the supernatants of the cells infected with the pandemic influenza virus. HTE and HNE cells exhibited mRNA and/or protein expression of transmembrane protease serine 2 (TMPRSS2), TMPRSS4, and TMPRSS11D. Pretreatment with nafamostat reduced cleavage of the precursor protein HA0 of the pandemic influenza virus into subunit HA1 in HTE cells and reduced the number of acidic endosomes in HTE and HNE cells where influenza virus RNA enters the cytoplasm. Additionally, nafamostat (30 mg/kg/day, intraperitoneal administration) reduced the levels of the pandemic influenza virus [A/Hyogo/YS/2011 (H1N1) pdm09] in mouse lung washes. These findings suggest that nafamostat may inhibit influenza virus replication in human airway epithelial cells and mouse lungs and reduce infection-induced airway inflammation by modulating cytokine production.
  • Makoto Saito, Yasushi Itoh, Fumihiko Yasui, Tsubasa Munakata, Daisuke Yamane, Makoto Ozawa, Risa Ito, Takayuki Katoh, Hirohito Ishigaki, Misako Nakayama, Shintaro Shichinohe, Kenzaburo Yamaji, Naoki Yamamoto, Ai Ikejiri, Tomoko Honda, Takahiro Sanada, Yoshihiro Sakoda, Hiroshi Kida, Thi Quynh Mai Le, Yoshihiro Kawaoka, Kazumasa Ogasawara, Kyoko Tsukiyama-Kohara, Hiroaki Suga, Michinori Kohara
    Nature communications 12 (1) 2654 - 2654 2021/05/11 [Refereed]
     
    Most anti-influenza drugs currently used, such as oseltamivir and zanamivir, inhibit the enzymatic activity of neuraminidase. However, neuraminidase inhibitor-resistant viruses have already been identified from various influenza virus isolates. Here, we report the development of a class of macrocyclic peptides that bind the influenza viral envelope protein hemagglutinin, named iHA. Of 28 iHAs examined, iHA-24 and iHA-100 have inhibitory effects on the in vitro replication of a wide range of Group 1 influenza viruses. In particular, iHA-100 bifunctionally inhibits hemagglutinin-mediated adsorption and membrane fusion through binding to the stalk domain of hemagglutinin. Moreover, iHA-100 shows powerful efficacy in inhibiting the growth of highly pathogenic influenza viruses and preventing severe pneumonia at later stages of infection in mouse and non-human primate cynomolgus macaque models. This study shows the potential for developing cyclic peptides that can be produced more efficiently than antibodies and have multiple functions as next-generation, mid-sized biomolecules.
  • Naoki Nomura, Keita Matsuno, Masashi Shingai, Marumi Ohno, Toshiki Sekiya, Ryosuke Omori, Yoshihiro Sakoda, Robert G Webster, Hiroshi Kida
    Virology 557 55 - 61 2021/05 [Refereed]
     
    Genetic reassortment of influenza A viruses through cross-species transmission contributes to the generation of pandemic influenza viruses. To provide information on the ecology of influenza viruses, we have been conducting a global surveillance of zoonotic influenza and establishing an influenza virus library. Of 4580 influenza virus strains in the library, 3891 have been isolated from over 70 different bird species. The remaining 689 strains were isolated from humans, pigs, horses, seal, whale, and the environment. Phylogenetic analyses of the HA genes of the library isolates demonstrate that the library strains are distributed to all major known clusters of the H1, H2 and H3 subtypes of HA genes that are prevalent in humans. Since past pandemic influenza viruses are most likely genetic reassortants of zoonotic and seasonal influenza viruses, a vast collection of influenza A virus strains from various hosts should be useful for vaccine preparation and diagnosis for future pandemics.
  • Enkhbold Bazarragchaa, Norikazu Isoda, Taksoo Kim, Madoka Tetsuo, Satoshi Ito, Keita Matsuno, Yoshihiro Sakoda
    Viruses 13 (2) 2021/02/20 [Refereed]
     
    Classical swine fever virus (CSFV) in the wild boar population has been spreading in Japan, alongside outbreaks on pigs, since classical swine fever (CSF) reemerged in September 2018. The vaccination using oral bait vaccine was initially implemented in Gifu prefecture in March 2019. In the present study, antibodies against CSFV in wild boar were assessed in 1443 captured and dead wild boars in Gifu prefecture. After the implementation of oral vaccination, the increase of the proportion of seropositive animals and their titer in wild boars were confirmed. Quantitative analysis of antigen and antibodies against CSFV in wild boar implies potential disease diversity in the wild boar population. Animals with status in high virus replication (Ct < 30) and non- or low-immune response were confirmed and were sustained at a certain level after initial oral vaccination. Through continuous vaccination periods, the increase of seroprevalence among wild boar and the decrease of CSFV-positive animals were observed. The epidemiological analysis based on the quantitative virological outcomes could provide more information on the efficacy of oral vaccination and dynamics of CSF in the wild boar population, which will help to improve the implementation of control measures for CSF in countries such as Japan and neighboring countries.
  • Saori Suzuki, Cong Thanh Nguyen, Ayako Ogata-Nakahara, Akihiro Shibata, Hiroyuki Osaka, Hirohito Ishigaki, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida, Kazumasa Ogasawara, Yasushi Itoh
    Antimicrobial agents and chemotherapy 65 (3) 2021/02/17 [Refereed]
     
    H7N9 highly pathogenic avian influenza virus (HPAIV) infection in a human was first reported in 2017. A/duck/Japan/AQ-HE29-22/2017 (H7N9) (Dk/HE29-22), found in imported duck meat at an airport in Japan, possesses a hemagglutinin with a multibasic cleavage site, indicating high pathogenicity in chickens, as in the case of other H7 HPAIVs. In the present study, we examined the pathogenicity of Dk/HE29-22 and the effectiveness of a cap-dependent endonuclease inhibitor (baloxavir) and neuraminidase inhibitors (oseltamivir and zanamivir) against infection with this strain in a macaque model (n = 3 for each group). All of the macaques infected with Dk/HE29-22 showed severe signs of disease and pneumonia even after the virus had disappeared from lung samples. Virus titers in macaques treated with baloxavir were significantly lower than those in the other treated groups. After infection, levels of interferon alpha and beta (IFN-α and IFN-β) in the blood of macaques in the baloxavir group were the highest among the groups, whereas levels of tumor necrosis factor alpha (TNF-α) and interleukin 13 (IL-13) were slightly increased in the untreated group. In addition, immune checkpoint proteins, including programmed death 1 (PD-1) and T cell immunoreceptor with Ig and ITIM domains (TIGIT), were expressed at high levels in the untreated group, especially in one macaque that showed severe signs of disease, indicating that negative feedback responses against vigorous inflammation may contribute to disease progression. In the group treated with baloxavir, the percentages of PD-1-, CTLA-4-, and TIGIT-positive T lymphocytes were lower than those in the untreated group, indicating that reduction in virus titers may prevent expression of immune checkpoint molecules from downregulation of T cell responses.
  • Marina Gulyaeva, Falk Huettmann, Alexander Shestopalov, Masatoshi Okamatsu, Keita Matsuno, Duc-Huy Chu, Yoshihiro Sakoda, Alexandra Glushchenko, Elaina Milton, Eric Bortz
    Scientific reports 11 (1) 3758 - 3758 2021/02/08 [Refereed]
  • Augustin T Twabela, Lam Thanh Nguyen, Justin Masumu, Patrick Mpoyo, Serge Mpiana, Julienne Sumbu, Masatoshi Okamatsu, Keita Matsuno, Norikazu Isoda, Bianca Zecchin, Isabella Monne, Yoshihiro Sakoda
    Viruses 13 (2) 2021/01/20 [Refereed]
     
    Newcastle disease (ND) is a highly transmissible and devastating disease that affects poultry and wild birds worldwide. Comprehensive knowledge regarding the characteristics and epidemiological factors of the ND virus (NDV) is critical for the control and prevention of ND. Effective vaccinations can prevent and control the spread of the NDV in poultry populations. For decades, the Democratic Republic of the Congo (DRC) has reported the impacts of ND on commercial and traditional poultry farming systems. The reports were preliminary clinical observations, and few cases were confirmed in the laboratory. However, data on the phylogenetic, genetic, and virological characteristics of NDVs circulating in the DRC are not available. In this study, the whole-genome sequences of three NDV isolates obtained using the next-generation sequencing method revealed two isolates that were a new variant of NDV, and one isolate that was clustered in the subgenotype VII.2. All DRC isolates were velogenic and were antigenically closely related to the vaccine strains. Our findings reveal that despite the circulation of the new variant, ND can be controlled in the DRC using the current vaccine. However, epidemiological studies should be conducted to elucidate the endemicity of the disease so that better control strategies can be implemented.
  • Hirotaka Hayashi, Norikazu Isoda, Enkhbold Bazarragchaa, Naoki Nomura, Keita Matsuno, Masatoshi Okamatsu, Hiroshi Kida, Yoshihiro Sakoda
    Vaccines 8 (4) 2020/12/16 [Refereed]
     
    H4 influenza viruses have been isolated from birds across the world. In recent years, an H4 influenza virus infection has been confirmed in pigs. Pigs play an important role in the transmission of influenza viruses to human hosts. Therefore, it is important to develop a new vaccine in the case of an H4 influenza virus infection in humans, considering that this virus has a different antigenicity from seasonal human influenza viruses. In this study, after selecting vaccine candidate strains based on their antigenic relation to one of the pig isolates, A/swine/Missouri/A01727926/2015 (H4N6) (MO/15), an inactivated whole-particle vaccine was prepared from A/swan/Hokkaido/481102/2017 (H4N6). This vaccine showed high immunogenicity in mice, and the antibody induced by the vaccine showed high cross-reactivity to the MO/15 virus. This vaccine induced sufficient neutralizing antibodies and mitigated the effects of an MO/15 infection in a mouse model. This study is the first to suggest that an inactivated whole-particle vaccine prepared from an influenza virus isolated from wild birds is an effective countermeasure in case of a future influenza pandemic caused by the H4 influenza virus.
  • Norikazu Isoda, Augustin T Twabela, Enkhbold Bazarragchaa, Kohei Ogasawara, Hirotaka Hayashi, Zu-Jyun Wang, Daiki Kobayashi, Yukiko Watanabe, Keisuke Saito, Hiroshi Kida, Yoshihiro Sakoda
    Viruses 12 (12) 2020/12/14 [Refereed]
     
    Global dispersion of high pathogenicity avian influenza (HPAI), especially that caused by H5 clade 2.3.4.4, has threatened poultry industries and, potentially, human health. An HPAI virus, A/northern pintail/Hokkaido/M13/2020 (H5N8) (NP/Hok/20) belonging to clade 2.3.4.4b, was isolated from a fecal sample collected at a lake in Hokkaido, Japan where migratory birds rested, October 2020. In the phylogenetic trees of all eight gene segments, NP/Hok/20 fell into in the cluster of European isolates in 2020, but was distinct from the isolates in eastern Asia and Europe during the winter season of 2017-2018. The antigenic cartography indicates that the antigenicity of NP/Hok/20 was almost the same as that of previous isolates of H5 clade 2.3.4.4b, whereas the antigenic distances from NP/Hok/20 to the representative strains in clade 2.3.4.4e and to a strain in 2.3.4 were apparently distant. These data imply that HPAI virus clade 2.3.4.4b should have been delivered by bird migration despite the intercontinental distance, although it was not defined whether NP/Hok/20 was transported from Europe via Siberia where migratory birds nest in the summer season. Given the probability of perpetuation of transmission in the northern territory, periodic updates of intensive surveys on avian influenza at the global level are essential to prepare for future outbreaks of the HPAI virus.
  • Augustin Twabela, Masatoshi Okamatsu, Keita Matsuno, Norikazu Isoda, Yoshihiro Sakoda
    Viruses 12 (12) 2020/12/08 [Refereed]
     
    Control measures in the case of high pathogenicity avian influenza (HPAI) outbreaks in poultry include culling, surveillance, and biosecurity; wild birds in captivity may also be culled, although some rare bird species should be rescued for conservation. In this study, two anti-influenza drugs, baloxavir marboxil (BXM) and peramivir (PR), used in humans, were examined in treating HPAI in birds, using chickens as a model. Chickens were infected with H5N6 HPAI virus and were treated immediately or 24 h from challenge with 20 mg/kg BXM or PR twice a day for five days. As per our findings, BXM significantly reduced virus replication in organs and provided full protection to chickens compared with that induced by PR. In the 24-h-delayed treatment, neither drug completely inhibited virus replication nor ensured the survival of infected chickens. A single administration of 2.5 mg/kg of BXM was determined as the minimum dose required to fully protect chickens from HPAI virus; the concentration of baloxavir acid, the active form of BXM, in chicken blood at this dose was sufficient for a 48 h antiviral effect post-administration. Thus, these data can be a starting point for the use of BXM and PR in treating captive wild birds infected with HPAI virus.
  • Llilianne Ganges, Helen R Crooke, Jose Alejandro Bohórquez, Alexander Postel, Yoshihiro Sakoda, Paul Becher, Nicolas Ruggli
    Virus research 289 198151 - 198151 2020/11 [Refereed][Not invited]
     
    Classical swine fever (CSF) is among the most relevant viral epizootic diseases of swine. Due to its severe economic impact, CSF is notifiable to the world organisation for animal health. Strict control policies, including systematic stamping out of infected herds with and without vaccination, have permitted regional virus eradication. Nevertheless, CSF virus (CSFV) persists in certain areas of the world and has re-emerged regularly. This review summarizes the basic established knowledge in the field and provides a comprehensive and updated overview of the recent advances in fundamental CSFV research, diagnostics and vaccine development. It covers the latest discoveries on the genetic diversity of pestiviruses, with implications for taxonomy, the progress in understanding disease pathogenesis, immunity against acute and persistent infections, and the recent findings in virus-host interactions and virulence determinants. We also review the progress and pitfalls in the improvement of diagnostic tools and the challenges in the development of modern and efficacious marker vaccines compatible with serological tests for disease surveillance. Finally, we highlight the gaps that require research efforts in the future.
  • Naoki Kajiwara, Namiko Nomura, Masako Ukaji, Naoki Yamamoto, Michinori Kohara, Fumihiko Yasui, Yoshihiro Sakoda, Hiroshi Kida, Futoshi Shibasaki
    Scientific reports 10 (1) 18008 - 18008 2020/10/22 [Refereed]
     
    H5N1 highly pathogenic avian influenza virus (HPAIV) poses a huge threat to public health and the global economy. These viruses cause systemic infection in poultry and accidental human infection leads to severe pneumonia, associated with high mortality rates. The hemagglutinin (HA) of H5N1 HPAIV possesses multiple basic amino acids, as in the sequence RERRRKKR at the cleavage site; however, the role of this motif is not fully understood. Here, we showed that a 33-amino acid long peptide derived from HA of H5N1 HPAIV (HA314-46) has the potential to penetrate various cells and lung tissue through a sialic acid-independent endocytotic pathway. Mutant peptide analyses revealed that the cysteine residue at position 318 and multiple basic amino acids were essential for the cell-penetrating activity. Moreover, reassortant viruses possessing H5 HA could enter sialic acid-deficient cells, and virus internalisation was facilitated by cleavage with recombinant furin. Thus, our findings demonstrate that the HA314-46 motif exhibits cell-penetrating activity through a sialic acid-independent cell entry mechanism.
  • Marina Gulyaeva, Falk Huettmann, Alexander Shestopalov, Masatoshi Okamatsu, Keita Matsuno, Duc-Huy Chu, Yoshihiro Sakoda, Alexandra Glushchenko, Elaina Milton, Eric Bortz
    Scientific reports 10 (1) 16817 - 16817 2020/10/08 [Refereed][Not invited]
     
    Avian Influenza (AI) is a complex but still poorly understood disease; specifically when it comes to reservoirs, co-infections, connectedness and wider landscape perspectives. Low pathogenic (Low-path LP) AI in chickens caused by less virulent strains of AI viruses (AIVs)-when compared with highly pathogenic AIVs (HPAIVs)-are not even well-described yet or known how they contribute to wider AI and immune system issues. Co-circulation of LPAIVs with HPAIVs suggests their interactions in their ecological aspects. Here we show for the Pacific Rim an international approach how to data mine and model-predict LP AI and its ecological niche with machine learning and open access data sets and geographic information systems (GIS) on a 5 km pixel size for best-possible inference. This is based on the best-available data on the issue (~ 40,827 records of lab-analyzed field data from Japan, Russia, Vietnam, Mongolia, Alaska and Influenza Research Database (IRD) and U.S. Department of Agriculture (USDA) database sets, as well as 19 GIS data layers). We sampled 157 hosts and 110 low-path AIVs with 32 species as drivers. The prevalence across low-path AIV subtypes is dominated by Muscovy ducks, Mallards, Whistling Swans and gulls also emphasizing industrial impacts for the human-dominated wildlife contact zone. This investigation sets a good precedent for the study of reservoirs, big data mining, predictions and subsequent outbreaks of HPAI and other pandemics.
  • Ankhanbaatar Ulaankhuu, Enkhbold Bazarragchaa, Masatoshi Okamatsu, Takahiro Hiono, Khishgee Bodisaikhan, Tsolmon Amartuvshin, Jargalsaikhan Tserenjav, Tsogtbaatar Urangoo, Khanui Buyantogtokh, Keita Matsuno, Takanari Hattori, Tatsunari Kondoh, Masahiro Sato, Yoshihiro Takadate, Shiho Torii, Mao Isono, Kosuke Okuya, Takeshi Saito, Nodoka Kasajima, Yurie Kida, Junki Maruyama, Manabu Igarashi, Ayato Takada, Hiroshi Kida, Damdinjav Batchuluun, Yoshihiro Sakoda
    Virus genes 56 (4) 472 - 479 2020/08 [Refereed][Not invited]
     
    The circulation of highly pathogenic avian influenza viruses (HPAIVs) of various subtypes (e.g., H5N1, H5N6, H5N8, and H7N9) in poultry remains a global concern for animal and public health. Migratory waterfowls play important roles in the transmission of these viruses across countries. To monitor virus spread by wild birds, active surveillance for avian influenza in migratory waterfowl was conducted in Mongolia from 2015 to 2019. In total, 5000 fecal samples were collected from lakesides in central Mongolia, and 167 influenza A viruses were isolated. Two H5N3, four H7N3, and two H7N7 viruses were characterized in this study. The amino acid sequence at hemagglutinin (HA) cleavage site of those isolates suggested low pathogenicity in chickens. Phylogenetic analysis revealed that all H5 and H7 viruses were closely related to recent H5 and H7 low pathogenic avian influenza viruses (LPAIVs) isolated from wild birds in Asia and Europe. Antigenicity of H7Nx was similar to those of typical non-pathogenic avian influenza viruses (AIVs). While HPAIVs or A/Anhui/1/2013 (H7N9)-related LPAIVs were not detected in migratory waterfowl in Mongolia, sporadic introductions of AIVs including H5 and H7 viruses into Mongolia through the wild bird migration were identified. Thus, continued monitoring of H5 and H7 AIVs in both domestic and wild birds is needed for the early detection of HPAIVs spread into the country.
  • Hirotaka Hayashi, Masatoshi Okamatsu, Honami Ogasawara, Naoko Tsugawa, Norikazu Isoda, Keita Matsuno, Yoshihiro Sakoda
    Nutrients 12 (7) 2020/07/05 [Refereed][Not invited]
     
    Vitamin D is a fat-soluble vitamin that is metabolized by the liver into 25-hydroxyvitamin D [25(OH)D] and then by the kidney into 1,25-dihydroxyvitamin D [1,25(OH)2D], which activates the vitamin D receptor expressed in various cells, including immune cells, for an overall immunostimulatory effect. Here, to investigate whether oral supplementation of 25-hydroxyvitamin D3 [25(OH)D3], a major form of vitamin D metabolite 25(OH)D, has a prophylactic effect on influenza A virus infection, mice were fed a diet containing a high dose of 25(OH)D3 and were challenged with the influenza virus. In the lungs of 25(OH)D3-fed mice, the viral titers were significantly lower than in the lungs of standardly fed mice. Additionally, the proinflammatory cytokines IL-5 and IFN-γ were significantly downregulated after viral infection in 25(OH)D3-fed mice, while anti-inflammatory cytokines were not significantly upregulated. These results indicate that 25(OH)D3 suppresses the production of inflammatory cytokines and reduces virus replication and clinical manifestations of influenza virus infection in a mouse model.
  • Cong Thanh Nguyen, Saori Suzuki, Yasushi Itoh, Hirohito Ishigaki, Misako Nakayama, Kaori Hayashi, Keita Matsuno, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida, Kazumasa Ogasawara
    Antimicrobial agents and chemotherapy 64 (7) 2020/06/23 [Refereed][Not invited]
     
    Attention has been paid to H5N6 highly pathogenic avian influenza virus (HPAIV) because of its heavy burden on the poultry industry and human mortality. Since an influenza A virus carrying N6 neuraminidase (NA) has never spread in humans, the potential for H5N6 HPAIV to cause disease in humans and the efficacy of antiviral drugs against the virus need to be urgently assessed. We used nonhuman primates to elucidate the pathogenesis of H5N6 HPAIV as well as to determine the efficacy of antiviral drugs against the virus. H5N6 HPAIV infection led to high fever in cynomolgus macaques. The lung injury caused by the virus was severe, with diffuse alveolar damage and neutrophil infiltration. In addition, an increase in interferon alpha (IFN-α) showed an inverse correlation with virus titers during the infection process. Oseltamivir was effective for reducing H5N6 HPAIV propagation, and continuous treatment with peramivir reduced virus propagation and the severity of symptoms in the early stage. This study also showed pathologically severe lung injury states in cynomolgus macaques infected with H5N6 HPAIV, even in those that received early antiviral drug treatments, indicating the need for close monitoring and further studies on virus pathogenicity and new antiviral therapies.
  • Saori Suzuki, Shintaro Shichinohe, Yasushi Itoh, Misako Nakayama, Hirohito Ishigaki, Yuya Mori, Ayako Ogata-Nakahara, Cong Thanh Nguyen, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida, Kazumasa Ogasawara
    Antiviral research 178 104790 - 104790 2020/06 [Refereed][Not invited]
     
    Human cases of H7N9 influenza A virus infection have been increasing since 2013. The first choice of treatment for influenza is neuraminidase (NA) inhibitors (NAIs), but there is a concern that NAI-resistant viruses are selected in the presence of NAIs. In our previous study, an H7N9 virus carrying AA substitution of threonine (T) for isoleucine (I) at residue 222 in NA (NA222T, N2 numbering) and an H7N9 virus carrying AA substitution of lysine (K) for arginine (R) at residue 292 in NA (NA292K, N2 numbering) were found in different macaques that had been infected with A/Anhui/1/2013 (H7N9) and treated with NAIs. In the present study, the variant with NA292K showed not only resistance to NAIs but also lower replication activity in MDCK cells than did the virus with wild-type NA, whereas the variant with NA222T, which was less resistant to NAIs, showed replication activity similar to that of the wild-type virus. Next, we examined the pathogenicity of these H7N9 NAI-resistant viruses in macaques. The variants caused clinical signs similar to those caused by the wild-type virus with similar replication potency. However, the virus with NA292K was replaced within 7 days by that with NA292R (same as the wild-type) in nasal samples from macaques infected with the virus with NA292K, i.e. the so-called revertant (wild-type virus) became dominant in the population in the absence of an NAI. These results suggest that the clinical signs observed in macaques infected with the NA292K virus are caused by the NA292K virus and the NA292R virus and that the virus with NA292K may not replicate continuously in the upper respiratory tract of patients without treatment as effectively as the wild-type virus.
  • Andrea Laconi, Andrea Fortin, Giulia Bedendo, Akihiro Shibata, Yoshihiro Sakoda, Joseph Adongo Awuni, Emilie Go-Maro, Abdelsatar Arafa, Ali Safar Maken Ali, Calogero Terregino, Isabella Monne
    Scientific reports 10 (1) 8441 - 8441 2020/05/21 [Refereed]
     
    Avian influenza viruses (AIV) are negative sense RNA viruses posing a major threat to the poultry industry worldwide, with the potential to spread to mammals, including humans; hence, an accurate and rapid AIV diagnosis is essential. To date AIV detection relies on molecular methods, mainly RT-qPCR directed against AIV M gene segment. The evolution of AIV represents a relevant issue in diagnostic RT-qPCR due to possible mispriming and/or probe-binding failures resulting in false negative results. Consequently, RT-qPCR for AIV detection should be periodically re-assessed both in silico and in vitro. To this end, a specific workflow was developed to evaluate in silico the complementarity of primers and probes of four published RT-qPCR protocols to their target regions. The four assays and one commercially available kit for AIV detection were evaluated both for their analytical sensitivity using eight different viral dilution panels and for their diagnostic performances against clinical specimens of known infectious status. Differences were observed among the tests under evaluation, both in terms of analytical sensitivity and of diagnostic performances. This finding confirms the importance of continuously monitoring the primers and probes complementarity to their binding regions.
  • Lam Thanh Nguyen, Mark A Stevenson, Simon M Firestone, Leslie D Sims, Duc Huy Chu, Long Van Nguyen, Tien Ngoc Nguyen, Kien Trung Le, Norikazu Isoda, Keita Matsuno, Masatoshi Okamatsu, Hiroshi Kida, Yoshihiro Sakoda
    Preventive veterinary medicine 178 104678 - 104678 0167-5877 2020/05 [Refereed][Not invited]
     
    The aim of this study was to describe the spatiotemporal distribution of H5 HPAI outbreak reports for the period 2014-2017 and to identify factors associated with H5 HPAI outbreak reports. Throughout the study period, a total of 139 outbreaks of H5 HPAI in poultry were reported, due to either H5N1 (96 outbreaks) or H5N6 (43 outbreaks) subtype viruses. H5N1 HPAI outbreaks occurred in all areas of Vietnam while H5N6 HPAI outbreaks were only reported in the northern and central provinces. We counted the number of H5N1 and H5N6 outbreak report-positive districts per province over the four-year study period and calculated the provincial-level standardized morbidity ratio for H5N1 and H5N6 outbreak reports as the observed number of positive districts divided by the expected number. A mixed-effects, zero-inflated Poisson regression model was developed to identify risk factors for outbreak reports of each H5N1 and H5N6 subtype virus. Spatially correlated and uncorrelated random effects terms were included in this model to identify areas of the country where outbreak reports occurred after known risk factors had been accounted-for. The presence of an outbreak report in a province in the previous 6-12 months increased the provincial level H5N1 outbreak report risk by a factor of 2.42 (95% Bayesian credible interval [CrI] 1.27-4.60) while 1000 bird increases in the density of chickens decreased provincial level H5N6 outbreak report risk by a factor of 0.65 (95% CrI 0.38 to 0.97). We document distinctly different patterns in the spatial and temporal distribution of H5N1 and H5N6 outbreak reports. Most of the variation in H5N1 report risk was accounted-for by the fixed effects included in the zero-inflated Poisson model. In contrast, the amount of unaccounted-for risk in the H5N6 model was substantially greater than the H5N1 model. For H5N6 we recommend that targeted investigations should be carried out in provinces with relatively large spatially correlated random effect terms to identify likely determinants of disease. Similarly, investigations should be carried out in provinces with relatively low spatially correlated random effect terms to identify protective factors for disease and/or reasons for failure to report.
  • Yuto Kikutani, Masatoshi Okamatsu, Shoko Nishihara, Sayaka Takase-Yoden, Takahiro Hiono, Robert P de Vries, Ryan McBride, Keita Matsuno, Hiroshi Kida, Yoshihiro Sakoda
    Microbiology and immunology 64 (4) 304 - 312 2020/04 [Refereed][Not invited]
     
    Avian influenza viruses (AIVs) recognize sialic acid linked α2,3 to galactose (SAα2,3Gal) glycans as receptors. In this study, the interactions between hemagglutinins (HAs) of AIVs and sulfated SAα2,3Gal glycans were analyzed to clarify the molecular basis of interspecies transmission of AIVs from ducks to chickens. It was revealed that E190V and N192D substitutions of the HA increased the recovery of viruses derived from an H6 duck virus isolate, A/duck/Hong Kong/960/1980 (H6N2), in chickens. Recombinant HAs from an H6 chicken virus, A/chicken/Tainan/V156/1999 (H6N1), bound to sulfated SAα2,3Gal glycans, whereas the HAs from an H6 duck virus did not. Binding preference of mutant HAs revealed that an E190V substitution is critical for the recognition of sulfated SAα2,3Gal glycans. These results suggest that the binding of the HA from H6 AIVs to sulfated SAα2,3Gal glycans explains a part of mechanisms of interspecies transmission of AIVs from ducks to chickens.
  • Madoka Tetsuo, Keita Matsuno, Tomokazu Tamura, Takasuke Fukuhara, Taksoo Kim, Masatoshi Okamatsu, Norbert Tautz, Yoshiharu Matsuura, Yoshihiro Sakoda
    Pathogens (Basel, Switzerland) 9 (3) 2020/03/04 [Refereed][Not invited]
     
    A serum neutralization test (SNT) is an essential method for the serological diagnosis of pestivirus infections, including classical swine fever, because of the cross reactivity of antibodies against pestiviruses and the non-quantitative properties of antibodies in an enzyme-linked immunosorbent assay. In conventional SNTs, an immunoperoxidase assay or observation of cytopathic effect after incubation for 3 to 7 days is needed to determine the SNT titer, which requires labor-intensive or time-consuming procedures. Therefore, a new SNT, based on the luciferase system and using classical swine fever virus, bovine viral diarrhea virus, and border disease virus possessing the 11-amino-acid subunit derived from NanoLuc luciferase was developed and evaluated; this approach enabled the rapid and easy determination of the SNT titer using a luminometer. In the new method, SNT titers can be determined tentatively at 2 days post-infection (dpi) and are comparable to those obtained by conventional SNTs at 3 or 4 dpi. In conclusion, the luciferase-based SNT can replace conventional SNTs as a high-throughput antibody test for pestivirus infections.
  • Kien Trung Le, Masatoshi Okamatsu, Lam Thanh Nguyen, Keita Matsuno, Duc-Huy Chu, Tien Ngoc Tien, Tung Thanh Le, Hiroshi Kida, Yoshihiro Sakoda
    Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases 78 104117 - 104117 2020/03 [Refereed][Not invited]
     
    During the annual surveillance of avian influenza viruses (AIVs) in Vietnam in 2018, three H7N7 AIV isolates were identified in domestic ducks in a single flock in Vinh Long province. The present study is the first documented report of H7N7 virus isolates in Vietnam and aimed to characterize these viruses, both genetically and antigenically. Deduced amino acid sequences for the hemagglutinins (HAs) indicated a low pathogenicity of these viruses in chickens. Phylogenetic analysis revealed that the H7 HA genes of these isolates were closely related to each other and belonged to the European-Asian sublineage, together with those of H7N3 viruses isolated from ducks in Cambodia during 2017. They were not genetically related to those of Chinese H7N9 or H7N1 viruses that were previously detected in Vietnam during 2012. Interestingly, the M genes of the two H7N7 virus isolates were phylogenetically classified into distinct groups, suggesting an ongoing reassortment event in domestic ducks because they were isolated from the same flock. These H7N7 viruses exhibited somewhat different antigenic characteristics compared with other representative H7 low pathogenic AIVs. Surprisingly, the antigenicity of Vietnamese H7N7 viruses is similar to Chinese H7N9 highly pathogenic AIV. The findings of this study suggest that H7N7 viruses may be undergoing reassortment and antigenic diversification in poultry flocks in Vietnam. The silent spread of Vietnamese H7N7 viruses in chickens may lead to acquire high pathogenicity in chickens although the zoonotic potential of the viruses seems to be low since these viruses retain typical avian-specific motifs in the receptor-binding site in the HA and there is no mutation related to mammalian adaptation in PB2 gene. Thus, these results highlight the need for continuous and intensive surveillance of avian influenza in Vietnam, targeting not only highly pathogenic AIVs but also low pathogenic viruses.
  • Norikazu Isoda, Kairi Baba, Satoshi Ito, Mitsugi Ito, Yoshihiro Sakoda, Kohei Makita
    Pathogens (Basel, Switzerland) 9 (2) 2020/02/13 [Refereed][Not invited]
     
    The prolongation of the classic swine fever (CSF) outbreak in Japan in 2018 was highly associated with the persistence and widespread of the CSF virus (CSFV) in the wild boar population. To investigate the dynamics of the CSF outbreak in wild boar, spatiotemporal analyses were performed. The positive rate of CSFV in wild boar fluctuated dramatically from March to June 2019, but finally stabilized at approximately 10%. The Euclidean distance from the initial CSF notified farm to the farthest infected wild boar of the day constantly increased over time since the initial outbreak except in the cases reported from Gunma and Saitama prefectures. The two-month-period prevalence, estimated using integrated nested Laplace approximation, reached >80% in half of the infected areas in March-April 2019. The area affected continued to expand despite the period prevalence decreasing up to October 2019. A large difference in the shapes of standard deviational ellipses and in the location of their centroids when including or excluding cases in Gunma and Saitama prefectures indicates that infections there were unlikely to have been caused simply by wild boar activities, and anthropogenic factors were likely involved. The emergence of concurrent space-time clusters in these areas after July 2019 indicated that CSF outbreaks were scattered by this point in time. The results of this epidemiological analysis help explain the dynamics of the spread of CSF and will aid in the implementation of control measures, including bait vaccination.
  • Yukari Itakura, Keita Matsuno, Asako Ito, Markus Gerber, Matthias Liniger, Yuri Fujimoto, Tomokazu Tamura, Ken-Ichiro Kameyama, Masatoshi Okamatsu, Nicolas Ruggli, Hiroshi Kida, Yoshihiro Sakoda
    Virus research 276 197809 - 197809 2020/01/15 [Refereed][Not invited]
     
    Classical swine fever viruses (CSFVs) do typically not show cytopathic effect (CPE) in cell culture, while some strains such as vaccine strain the GPE- induce CPE in the swine kidney-derived CPK-NS cell line cultured in serum-free medium. These latter strains commonly lack Npro-mediated inhibition of type-I interferon (IFN) induction. In order to explore the molecular mechanisms of GPE--induced CPE, we analyzed the cellular pathways involved. In CPK-NS cells infected with the attenuated-vaccine-derived vGPE- strain, both, apoptosis and necroptosis were induced. Necroptosis was type-I IFN-dependent and critical for visible CPE. In contrast, the parental virulent vALD-A76 strain did not induce any of these pathways nor CPE. We used reverse genetics to investigate which viral factors regulate these cell-death pathways. Interestingly, a mutant vGPE- in which the Npro function was restored to inhibit type-I IFN induction did not induce necroptosis nor CPE but still induced apoptosis, while an Npro-mutant vALD-A76 incapable of inhibiting type-I IFN production induced necroptosis and CPE. Although Erns of CSFV is reportedly involved in controlling apoptosis, apoptosis induction by vGPE- or apoptosis inhibition by vALD-A76 were independent of the unique amino acid difference found in Erns of these two strains. Altogether, these results demonstrate that type-I IFN-dependent necroptosis related to non-functional Npro is the main mechanism for CPE induction by vGPE-, and that viral factor(s) other than Erns may induce or inhibit apoptosis in vGPE- or vALD-A76 infected CPK-NS cells, respectively.
  • Taishi Kidaka, Sithumini M.W. Lokupathirage, Bungiriye Devinda Shameera Muthusinghe, Boniface Lombe Pongombo, Christida Estu Wastika, Zhouxing Wei, Shizuka Yoshioka, Mayumi Ishizuka, Yoshihiro Sakoda, Hiroaki Kariwa, Norikazu Isoda
    Japanese Journal of Veterinary Research 68 (3) 133 - 150 0047-1917 2020 
    An outbreak of novel coronavirus infection occurred in China at the end of 2019, which was designated as coronavirus disease 2019 (COVID-19), and spread to regions across Asia and ultimately all over the world. As of 21 May 2020, a total of more than 5 million cases with more than 350 thousand deaths were reported worldwide. Evaluation of the pathogenicity of the disease and determining the efficacy of control measures are essential for rapid containment of the disease. However, the world is facing difficulties in controlling COVID-19 at both of the national and global levels due to variations in pathogenicity of infection by severe acute respiratory syndrome coronavirus 2, the causal agent of COVID-19, and to diverse measures applied in each country based on their control capacities and policies. In the present review, we summarize the basic information and findings related to the COVID-19 pandemic, including pathogen agent, epidemiology, disease transmission, and clinical manifestations. Diagnosis, treatment, and preventive measures applied or under development all over the world are also reviewed to provide the opportunity to establish a more effective scenario for disease containment. Humanity has progressed by developing countless great technologies and immense scientific theories, however it may be a fact that we cannot conquer all risks to humanity. New findings and challenges for the unprecedented pandemic at the global level, such as COVID-19, should also contribute to preparedness for unknown diseases in future, similar to the lessons learnt from severe acute respiratory syndrome and the pandemic A(H1N1)pdm09 influenza.
  • Augustin T Twabela, Masatoshi Okamatsu, Georges Mbuyi Tshilenge, Serge Mpiana, Justin Masumu, Lam Thanh Nguyen, Keita Matsuno, Isabella Monne, Bianca Zecchin, Yoshihiro Sakoda
    Archives of virology 165 (1) 87 - 96 2020/01 [Refereed][Not invited]
     
    In May 2017, high mortality of chickens and Muscovy ducks due to the H5N8 highly pathogenic avian influenza virus (HPAIV) was reported in the Democratic Republic of Congo (DR Congo). In this study, we assessed the molecular, antigenic, and pathogenic features in poultry of the H5N8 HPAIV from the 2017 Congolese outbreaks. Phylogenetic analysis of the eight viral gene segments revealed that all 12 DR Congo isolates clustered in clade 2.3.4.4B together with other H5N8 HPAIVs isolated in Africa and Eurasia, suggesting a possible common origin of these viruses. Antigenically, a slight difference was observed between the Congolese isolates and a representative virus from group C in the same clade. After intranasal inoculation with a representative DR Congo virus, high pathogenicity was observed in chickens and Muscovy ducks but not in Pekin ducks. Viral replication was higher in chickens than in Muscovy duck and Pekin duck organs; however, neurotropism was pronounced in Muscovy ducks. Our data confirmed the high pathogenicity of the DR Congo virus in chickens and Muscovy ducks, as observed in the field. National awareness and strengthening surveillance in the region are needed to better control HPAIVs.
  • Mai Shiokawa, Tsutomu Omatsu, Yukie Katayama, Kaoru Nishine, Yuri Fujimoto, Shiori Uchiyama, Ken-Ichiro Kameyama, Makoto Nagai, Tetsuya Mizutani, Yoshihiro Sakoda, Akio Fukusho, Hiroshi Aoki
    Virology 538 97 - 110 2019/12 [Refereed][Not invited]
     
    Our previous study reported that persistently infected (PI) cattle of bovine viral diarrhea virus (BVDV) have co-infected with BVDV/END- and /END+ that promote and inhibit host's type-I interferon (IFN) production, respectively. However, the relationship between co-infection of immunologically distinct BVDVs and persistent infection as well as the biological significance of END- viruses remains unknown. Experiments using cultured cells revealed that END+ virus, which is unable to propagate in situations where the host's immune response is induced by IFN-α addition, is able to propagate under those conditions when co-infecting with END- virus. These results indicate that BVDV/END- can coexist with BVDV/END+ and that co-infection with END- viruses supports the propagation of END+ viruses. Our in vitro experiments strongly suggest that co-infection with END- virus is involved in the maintenance of persistent infection of BVDV.
  • Tomokazu Tamura, Manabu Igarashi, Bazarragchaa Enkhbold, Tatsuya Suzuki, Masatoshi Okamatsu, Chikako Ono, Hiroyuki Mori, Takuma Izumi, Asuka Sato, Yuzy Fauzyah, Toru Okamoto, Yoshihiro Sakoda, Takasuke Fukuhara, Yoshiharu Matsuura
    Journal of virology 93 (22) 0022-538X 2019/11/15 [Refereed][Not invited]
     
    Recombinant viruses possessing reporter proteins have been generated for virus research. In the case of the family Flaviviridae, we recently generated recombinant viruses, including the hepatitis C virus of the genus Hepacivirus, Japanese encephalitis virus (JEV) of the genus Flavivirus, and bovine viral diarrhea virus of the genus Pestivirus; all three viruses possess an 11-amino-acid subunit derived from NanoLuc luciferase (HiBiT). Here, we further developed the recombinant viruses and investigated their utility in vivo Recombinant viruses harboring HiBiT in the E, NS1, or NS3 protein constructed based on the predicted secondary structure, solvent-accessible surface area, and root mean square fluctuation of the proteins exhibited comparable replication to that of the wild-type virus in vitro The recombinant JEV carrying HiBiT in the NS1 protein exhibited propagation in mice comparable to that of the parental virus, and propagation of the recombinant was monitored by the luciferase activity. In addition, the recombinants of classical swine fever virus (CSFV) possessing HiBiT in the Erns or E2 protein also showed propagation comparable to that of the wild-type virus. The recombinant CSFV carrying HiBiT in Erns exhibited similar replication to the parental CSFV in pigs, and detection of viral propagation of this recombinant by luciferase activity was higher than that by quantitative PCR (qPCR). Taken together, these results demonstrated that the reporter Flaviviridae viruses generated herein are powerful tools for elucidating the viral life cycle and pathogeneses and provide a robust platform for the development of novel antivirals.IMPORTANCEIn vivo applications of reporter viruses are necessary to understand viral pathogenesis and provide a robust platform for antiviral development. In developing such applications, determination of an ideal locus to accommodate foreign genes is important, because insertion of foreign genes into irrelevant loci can disrupt the protein functions required for viral replication. Here, we investigated the criteria to determine ideal insertion sites of foreign genes from the protein structure of viral proteins. The recombinant viruses generated by our criteria exhibited propagation comparable to that of parental viruses in vivo Our proteomic approach based on the flexibility profile of viral proteins may provide a useful tool for constructing reporter viruses, including Flaviviridae viruses.
  • Takara Hajake, Keita Matsuno, Dacquin M Kasumba, Haruka Oda, Moe Kobayashi, Nao Miyata, Madoka Shinji, Amane Kogure, Nodoka Kasajima, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroki Kato, Takashi Fujita
    International immunology 31 (12) 811 - 821 0953-8178 2019/11/08 [Refereed][Not invited]
     
    Double-stranded RNA (dsRNA) is well characterized as an inducer of anti-viral interferon responses. We previously reported that dsRNA extracted from a specific edible plant possesses an immune-modulating capacity to confer, in mice, resistance against respiratory viruses, including the H1N1 strain of the influenza A virus (IAV). We report here that the systemic immune-activating capacity of the plant-derived dsRNA protected mice from infection by a highly virulent H5N1 strain of the IAV. In addition, subcutaneous inoculation of the dsRNA together with the inactivated virion of the H5N1 strain of the IAV suppressed the lethality of the viral infection as compared with individual inoculation of either dsRNA or HA protein, suggesting its potential usage as a vaccination adjuvant. Moreover, intra-peritoneal inoculation of the dsRNA limited the growth of B16-F10 melanoma cells through the activation of NK cells in murine models. Taken together, this study demonstrated the systemic immune-modulating capacity of a plant-derived dsRNA and its potential for nucleic acid-based clinical applications.
  • Satoshi Ito, Cristina Jurado, Jaime Bosch, Mitsugi Ito, José Manuel Sánchez-Vizcaíno, Norikazu Isoda, Yoshihiro Sakoda
    Pathogens (Basel, Switzerland) 8 (4) 2019/10/24 [Refereed][Not invited]
     
    Since September 2018, nearly 900 notifications of classical swine fever (CSF) have been reported in Gifu Prefecture (Japan) affecting domestic pig and wild boar by the end of August 2019. To determine the epidemiological characteristics of its spread, a spatio-temporal analysis was performed using actual field data on the current epidemic. The spatial study, based on standard deviational ellipses of official CSF notifications, showed that the disease likely spread to the northeast part of the prefecture. A maximum significant spatial association estimated between CSF notifications was 23 km by the multi-distance spatial cluster analysis. A space-time permutation analysis identified two significant clusters with an approximate radius of 12 and 20 km and 124 and 98 days of duration, respectively. When the area of the identified clusters was overlaid on a map of habitat quality, approximately 82% and 75% of CSF notifications, respectively, were found in areas with potential contact between pigs and wild boar. The obtained results provide information on the current CSF epidemic, which is mainly driven by wild boar cases with sporadic outbreaks on domestic pig farms. These findings will help implement control measures in Gifu Prefecture.
  • Mohammad Aref Agah, Kosuke Notsu, Heba M El-Khaiat, Genki Arikawa, Meiko Kubo, Shuya Mitoma, Tamaki Okabayashi, Hirohisa Mekata, Eslam Elhanafy, Hala El Daous, Thi Ngan Mai, Thi Huyen Nguyen, Norikazu Isoda, Yoshihiro Sakoda, Junzo Norimine, Satoshi Sekiguchi
    The Journal of veterinary medical science 81 (10) 1450 - 1454 0916-7250 2019/10/18 [Refereed][Not invited]
     
    Bovine viral diarrhea virus (BVDV) footprint has spread across the globe and is responsible for one of the most economically important diseases in cattle. In Japan, some regional surveillance and preventive measures to control bovine viral diarrhea (BVD) have been implemented. However, BVDV infection is poorly understood in cattle industries, and there is no systematic BVD surveillance system and control program. Kyushu is the center for raising beef cattle in Japan. Therefore, this study aimed to determine the BVDV infection using a slaughterhouse survey among beef cattle in Kyushu, Japan. A total of 1,075 blood samples were collected at two regional slaughterhouses in Miyazaki prefecture from December 2015 to June 2016. Antigen ELISA was used for detection of BVDV antigen in blood samples. Two samples showed positive results (2/1,075; 0.18%). BVDV RNA was extracted from positive blood samples; the sequence was determined and analyzed by the neighbor-joining method for construction of the phylogenetic tree. Phylogenetic analysis based on the 5'-UTR revealed that the two positive samples were grouped into the same subtype BVDV-1b in the BVDV-1 genotype, but the infected cattle belonged to two different farms. In conclusion, this is the first study to identify the presence of BVDV in a slaughterhouse survey in Kyushu. These findings suggest that a slaughterhouse survey is a useful tool for developing a surveillance system for monitoring infectious diseases in cattle.
  • Uyangaa Temuujin, Ariunaa Tserendorj, Jumpei Fujiki, Yoshihiro Sakoda, Erdene-Ochir Tseren-Ochir, Masatoshi Okamatsu, Keita Matsuno, Tumenjargal Sharav, Motohiro Horiuchi, Takashi Umemura, Tungalag Chultemdorj
    Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases 73 269 - 275 1567-1348 2019/09 [Refereed][Not invited]
     
    Canine parvovirus type 2 (CPV-2) causes a highly contagious and fatal disease, developing into acute hemorrhagic enteritis and myocarditis, in dogs. CPV-2 has evolved, generating antigenic variants CPV-2a/2b/2c that are globally distributed. However, investigating molecular characterization of CPV-2 among dog populations in Mongolia has been limited. Herein, 42 stool samples were collected from dogs with clinical signs of infection, and conventional PCR assays were employed to detect CPV-2 in 23. Our results indicated that during 2016-2018, the new CPV-2a and 2c subtypes were detected in 34.7% of the samples, and the new CPV-2b subtype was detected in 30.4% of samples. VP2 protein sequence analysis and next-generation sequencing of the complete viral genome confirmed these antigenic types. However, sequence analysis indicated new and unreported mutations, Pro580Thr, and Tyr584His in the CPV-2c subtype. From a PCR-positive sample, CPV-2c was successfully isolated, and we performed an immunofluorescence assay for antigen detection. Additionally, we performed genetic characterization and phylogenetic analysis to investigate genetic diversity among isolates from the region, resulting in high CPV-2 genetic diversity in the Mongolian dog population. Striking similarities were also observed between sequences of the strains isolated from Mongolia and China over a similar time span.
  • Sho Hideshima, Hiroki Hayashi, Hiroshi Hinou, Shunsuke Nambuya, Shigeki Kuroiwa, Takuya Nakanishi, Toshiyuki Momma, Shin-Ichiro Nishimura, Yoshihiro Sakoda, Tetsuya Osaka
    Scientific reports 9 (1) 11616 - 11616 2019/08/12 [Refereed][Not invited]
     
    Pandemic influenza, triggered by the mutation of a highly pathogenic avian influenza virus (IFV), has caused considerable damage to public health. In order to identify such pandemic IFVs, antibodies that specifically recognize viral surface proteins have been widely used. However, since the analysis of a newly discovered virus is time consuming, this delays the availability of suitable detection antibodies, making this approach unsuitable for the early identification of pandemic IFVs. Here we propose a label-free semiconductor-based biosensor functionalized with sialic-acid-containing glycans for the rapid identification of the pandemic IFVs present in biological fluids. Specific glycans are able to recognize wild-type human and avian IFVs, suggesting that they are useful in discovering pandemic IFVs at the early stages of an outbreak. We successfully demonstrated that a dual-channel integrated FET biosensing system, which were modified with 6'-sialyllactose and 3'-sialyllactose for each gate area, can directly and specifically detect human H1N1 and avian H5N1 IFV particles, respectively, present in nasal mucus. Furthermore, to examine the possibility of identifying pandemic IFVs, the signal attributed to the detection of Newcastle disease virus (NDV) particles, which was selected as a prime model of a pandemic IFV, was clearly observed from both sensing gates. Our findings suggest that the proposed glycan-immobilized sensing system could be useful in identifying new pandemic IFVs at the source of an outbreak.
  • Lam Thanh Nguyen, Simon M Firestone, Mark A Stevenson, Neil D Young, Leslie D Sims, Duc Huy Chu, Tien Ngoc Nguyen, Long Van Nguyen, Tung Thanh Le, Hung Van Nguyen, Hung Nam Nguyen, Tien Ngoc Tien, Tho Dang Nguyen, Bich Ngoc Tran, Keita Matsuno, Masatoshi Okamatsu, Hiroshi Kida, Yoshihiro Sakoda
    Scientific reports 9 (1) 7723 - 7723 2019/05/22 [Refereed][Not invited]
     
    This study aimed to elucidate virus, host and environmental dynamics of Vietnamese H5 highly pathogenic avian influenza viruses (HPAIVs) during 2014-2017. Epidemiologically, H5 HPAIVs were frequently detected in apparently healthy domestic and Muscovy ducks and therefore these are preferred species for H5 HPAIV detection in active surveillance. Virologically, clade 2.3.2.1c and 2.3.4.4 H5 HPAIVs were predominant and exhibited distinct phylogeographic evolution. Clade 2.3.2.1c viruses clustered phylogenetically in North, Central and South regions, whilst clade 2.3.4.4 viruses only detected in North and Central regions formed small groups. These viruses underwent diverse reassortment with existence of at least 12 genotypes and retained typical avian-specific motifs. These H5 HPAIVs exhibited large antigenic distance from progenitor viruses and commercial vaccines currently used in poultry. Bayesian phylodynamic analysis inferred that clade 2.3.2.1c viruses detected during 2014-2017 were likely descended from homologous clade viruses imported to Vietnam previously and/or preexisting Chinese viruses during 2012-2013. Vietnamese clade 2.3.4.4 viruses closely shared genetic traits with contemporary foreign spillovers, suggesting that there existed multiple transboundary virus dispersals to Vietnam. This study provides insights into the evolution of Vietnamese H5 HPAIVs and highlights the necessity of strengthening control measures such as, preventive surveillance and poultry vaccination.
  • Norikazu Isoda, Akihiro Asano, Michiru Ichijo, Hiroshi Ohno, Kazuhiko Sato, Hirokazu Okamoto, Shigeru Nakao, Hajime Kato, Kazuma Saito, Naoki Ito, Akira Usui, Hiroaki Takayama, Yoshihiro Sakoda
    The Journal of veterinary medical science 81 (4) 577 - 585 0916-7250 2019/04/16 [Refereed][Not invited]
     
    Bovine viral diarrhea (BVD) is a chronic disease of cattle caused by infection with BVD virus (BVDV) and can result in economic losses within the livestock industry. In Japan, the test and culling policy is a basic control measure, and implementation of an adequate vaccination program is recommended as a national policy. In addition, optional control measures, including compulsory testing of introduced animals and bulk tank milk (BTM) testing as a mass screening method, are used in several provinces, but their efficacy has not been completely assessed. We evaluated these control measures using the scenario tree model of BVD in Japan, developed in the previous study. The model outputs indicated that compulsory testing of all introduced cattle, rather than only heifers and/or non-vaccinated cattle, was cost effective and reduced the risk of BVDV introduction due to animal movement and that BTM testing could effectively monitor most part of the cattle population. Vaccination coverage and BVDV prevalence among introduced cattle could also affect the cost effectiveness of compulsory testing of targeted cattle, particularly under low vaccination coverage or high BVDV prevalence. However, even with the implementation of a highly effective monitoring scheme for many years, BVD risk could not be eliminated; it instead converged at a very low level (0.02%). Disease models with a cost-effective output could be a powerful tool in developing a control scheme for chronic animal diseases, including BVD, with the consent of relevant stakeholders.
  • Akihiro Shibata, Rieko Harada, Masatoshi Okamatsu, Keita Matsuno, Tomoko Arita, Yasushi Suzuki, Masayuki Shirakura, Takato Odagiri, Nobuhiro Takemae, Yuko Uchida, Takehiko Saito, Yoshihiro Sakoda, Hiroyuki Osaka
    The Journal of veterinary medical science 81 (3) 444 - 448 0916-7250 2019/03/20 [Refereed][Not invited]
     
    A new reassortant H7N3 avian influenza virus (AIV) was isolated from a duck meat product that was illegally taken on board a passenger flight from China to Japan in March 2018. Sequencing analysis revealed that the H7N3 isolate, A/duck/Japan/AQ-HE30-1/2018 (Dk/HE30-1) (H7N3), was a reassortant highly pathogenic avian influenza virus (HPAIV) that contained the haemagglutinin (HA) gene of Chinese H7N9 HPAIV. Dk/HE30-1 (H7N3) possessed a novel polybasic sequence motif PEVPKRRRTAR/GLF at the HA cleavage site that has never previously been reported in H7 HPAIVs. The HA antigenicity of Dk/HE30-1 (H7N3) slightly differed from that of H7N9 HPAIVs previously reported. These findings will help further our knowledge of the circulation and genetic evolution of emerging AIVs in endemic areas.
  • Keiichi Taniguchi, Yoshinori Ando, Haruaki Nobori, Shinsuke Toba, Takeshi Noshi, Masanori Kobayashi, Makoto Kawai, Ryu Yoshida, Akihiko Sato, Takao Shishido, Akira Naito, Keita Matsuno, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida
    Scientific reports 9 (1) 3466 - 3466 2019/03/05 [Refereed][Not invited]
     
    Human infections with avian-origin influenza A(H7N9) virus represent a serious threat to global health; however, treatment options are limited. Here, we show the inhibitory effects of baloxavir acid (BXA) and its prodrug baloxavir marboxil (BXM), a first-in-class cap-dependent endonuclease inhibitor, against A(H7N9), in vitro and in vivo. In cell culture, BXA at four nanomolar concentration achieved a 1.5-2.8 log reduction in virus titers of A(H7N9), including the NA-R292K mutant virus and highly pathogenic avian influenza viruses, whereas NA inhibitors or favipiravir required approximately 20-fold or higher concentrations to achieve the same levels of reduction. A(H7N9)-specific amino acid polymorphism at position 37, implicated in BXA binding to the PA endonuclease domain, did not impact on BXA susceptibility. In mice, oral administration of BXM at 5 and 50 mg/kg twice a day for 5 days completely protected from a lethal A/Anhui/1/2013 (H7N9) challenge, and reduced virus titers more than 2-3 log in the lungs. Furthermore, the potent therapeutic effects of BXM in mice were still observed when a higher virus dose was administered or treatment was delayed up to 48 hours post infection. These findings support further investigation of BXM for A(H7N9) treatment in humans.
  • Enkhbold Bazarragchaa, Masatoshi Okamatsu, Ankhanbaatar Ulaankhuu, Augustin Tshibwabwa Twabela, Keita Matsuno, Hiroshi Kida, Yoshihiro Sakoda
    Journal of virological methods 265 121 - 125 0166-0934 2019/03 [Refereed][Not invited]
     
    Rapid and accurate diagnosis of influenza virus infection is essential for quick responses for both human and animal health. The Alere™ i Influenza A&B is a novel isothermal nucleic acid amplification kit that can detect and differentiate between influenza A and B viruses in human specimens in approximately 15 min. In the present study, the performance of the Alere™ i Influenza A&B kit was evaluated for its ability to detect avian influenza virus in chickens. The kit was able to detect representative avian influenza virus strains (hemagglutinin subtypes H1-H16, including the recently isolated H5 and H7 highly pathogenic avian influenza viruses), and the detection limit of the kit for these viruses varied between 10-1.4-102.1 50% egg-infective dose per test, which is higher than the analytical sensitivity of the antigen detection immunochromatography kit ESPLINE® A INFLUENZA. In experimentally infected chickens inoculated with a highly pathogenic avian influenza virus strain A/chicken/Hokkaido/002/2016 (H5N6), viral RNA was detected in the tracheal and cloacal swabs. These results indicate that this kit has the potential to be used as a rapid screening test of influenza A virus infection in chickens.
  • Shiho Torii, Keita Matsuno, Yongjin Qiu, Akina Mori-Kajihara, Masahiro Kajihara, Ryo Nakao, Naganori Nao, Katsunori Okazaki, Mariko Sashika, Takahiro Hiono, Masatoshi Okamatsu, Yoshihiro Sakoda, Hideki Ebihara, Ayato Takada, Hirofumi Sawa
    Ticks and tick-borne diseases 10 (2) 328 - 335 1877-959X 2019/02 [Refereed][Not invited]
     
    Recent discoveries of tick-borne pathogens have raised public health concerns on tick-borne infectious diseases and emphasize the need to assess potential risks of unrecognized tick-borne pathogens. First, to determine the existence of tick-borne phleboviruses (TBPVs), genetic surveillance of phleboviruses in ticks was conducted mainly in Hokkaido, the northernmost island in Japan from 2013 to 2015. Genes of two TBPVs, previously reported as Mukawa virus (MKWV) and a newly identified relative of MKWV, Kuriyama virus (KURV), were detected and the viruses were isolated from Ixodes persulcatus collected in Hokkaido, but not in I. persulcatus collected from other areas of Japan. These viruses were phylogenetically and antigenically similar to each other. Next, to investigate the infection of MKWV in mammals, serum samples from wildlife captured in Hokkaido from 2007 to 2011 were used for serological screening. Neutralizing antibodies against MKWV were detected in both Yezo-deer (Cervus nippon yesoensis) (2/50) and raccoons (Procyon lotor) (16/64). However, no infectious MKWV was recovered from laboratory mice in experimental infections, though viral RNAs were detected in their tissues. Thus, MKWV and KURV may maintain tick-mammalian life cycles in Hokkaido, suggesting their potential as causative agents of tick-borne diseases in mammals.
  • Takahiro Hiono, Atsushi Matsuda, Takanori Wagatsuma, Masatoshi Okamatsu, Yoshihiro Sakoda, Atsushi Kuno
    Virology 527 132 - 140 0042-6822 2019/01/15 [Refereed][Not invited]
     
    Glycan structures on hemagglutinin (HA) of influenza A viruses have been analyzed previously to understand their significance. However, the formerly established methods using mass spectrometry present disadvantages such as procedure complexity, sensitivity, and throughput. Our study has established a novel method for analyzing glycan profiles of HA using lectin microarray techniques. We successfully obtained glycan profiles of HA starting from 1 ml of the 106 TCID50 samples through simple antigen enrichment using optimized immunoprecipitation. The profiles were reasonably consistent with known glycan structures of HA. Next, we compared glycan profiles of the HAs prepared from chicken embryos, MDCK, Vero, and A549 cells, and demonstrated the host cell-specific HA glycan profiles. Notably, the HA from MDCK cells was α1-3 galactosylated. Our method provides a highly sensitive and simple procedure for glycan profiling of the viral glycoproteins, thereby paving way for direct glycan analyses of human- and animal-derived virions.
  • Takashi Suzuki, Masatoshi Okamatsu, Yoshihiro Sakoda, Taroh Kinoshita, Takane Katayama, Hiroshi Kiyono, Yoshiyuki Goto, Kaoru Takegawa, Naoaki Yokoyama, Yukari Fujimoto, Takashi Angata, Katsuki Ohtani, Nobutaka Wakamiya, Hisashi Arase, Shoko Nishihara, Yasuo Suda
    Glycoscience: Basic Science to Applications: Insights from the Japan Consortium for Glycobiology and Glycotechnology (JCGG) 227 - 257 2019/01/01
  • Takeshi Noshi, Mitsutaka Kitano, Keiichi Taniguchi, Atsuko Yamamoto, Shinya Omoto, Keiko Baba, Takashi Hashimoto, Kayo Ishida, Yukihiro Kushima, Kazunari Hattori, Makoto Kawai, Ryu Yoshida, Masanori Kobayashi, Tomokazu Yoshinaga, Akihiko Sato, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida, Takao Shishido, Akira Naito
    Antiviral research 160 109 - 117 0166-3542 2018/12 [Refereed][Not invited]
     
    Cap-dependent endonuclease (CEN) resides in the PA subunit of the influenza virus and mediates the critical "cap-snatching" step of viral RNA transcription, which is considered to be a promising anti-influenza target. Here, we describe in vitro characterization of a novel CEN inhibitor, baloxavir acid (BXA), the active form of baloxavir marboxil (BXM). BXA inhibits viral RNA transcription via selective inhibition of CEN activity in enzymatic assays, and inhibits viral replication in infected cells without cytotoxicity in cytopathic effect assays. The antiviral activity of BXA is also confirmed in yield reduction assays with seasonal type A and B viruses, including neuraminidase inhibitor-resistant strains. Furthermore, BXA shows broad potency against various subtypes of influenza A viruses (H1N2, H5N1, H5N2, H5N6, H7N9 and H9N2). Additionally, serial passages of the viruses in the presence of BXA result in isolation of PA/I38T variants with reduced BXA susceptibility. Phenotypic and genotypic analyses with reverse genetics demonstrate the mechanism of BXA action via CEN inhibition in infected cells. These results reveal the in vitro characteristics of BXA and support clinical use of BXM to treat influenza.
  • Akihiro Shibata, Masatoshi Okamatsu, Riho Sumiyoshi, Keita Matsuno, Zu-Jyun Wang, Hiroshi Kida, Hiroyuki Osaka, Yoshihiro Sakoda
    Virology 524 10 - 17 0042-6822 2018/11 [Refereed][Not invited]
     
    H7N9 highly and low pathogenic avian influenza viruses (HPAIV and LPAIV, respectively) have been isolated from duck meat products that were brought illegally into Japan by flight passengers in their hand luggage. These H7N9 virus isolates were phylogenetically closely related to those prevailing in China. Antigenic analysis revealed that the hemagglutinin of the H7N9 HPAIV isolate was slightly different from those of the H7N9 LPAIV and older H7 strains. These meat products contaminated with AIVs repeatedly brought into Japan lead to increased risks of poultry and public health. Continuous border disease control based on the detection and culling of infected poultry and meat products is, thus, essential for the prevention of introduction and spread of AIVs.
  • Keita Matsuno, Noriyuki Nonoue, Ayako Noda, Nodoka Kasajima, Keita Noguchi, Ai Takano, Hiroshi Shimoda, Yasuko Orba, Mieko Muramatsu, Yoshihiro Sakoda, Ayato Takada, Shinji Minami, Yumi Une, Shigeru Morikawa, Ken Maeda
    Emerging infectious diseases 24 (9) 1726 - 1729 1080-6040 2018/09 [Refereed][Not invited]
     
    Two captive cheetahs from a zoo in Japan died of a severe fever with thrombocytopenia syndrome-like illness. Severe fever with thrombocytopenia syndrome virus, an endemic tickborne phlebovirus, was detected systemically with secretion of infectious viruses into the saliva. These cases highlight the risk for exposure of captive animals to endemic arthropodborne pathogens.
  • Zu-Jyun Wang, Yuto Kikutani, Lam Thanh Nguyen, Takahiro Hiono, Keita Matsuno, Masatoshi Okamatsu, Scott Krauss, Richard Webby, Youn-Jeong Lee, Hiroshi Kida, Yoshihiro Sakoda
    Virus genes 54 (4) 543 - 549 0920-8569 2018/08 [Refereed][Not invited]
     
    Among 16 haemagglutinin (HA) subtypes of avian influenza viruses (AIVs), H13 AIVs have rarely been isolated in wild waterfowl. H13 AIVs cause asymptomatic infection and are maintained mainly in gull and tern populations; however, the recorded antigenic information relating to the viruses has been limited. In this study, 2 H13 AIVs, A/duck/Hokkaido/W345/2012 (H13N2) and A/duck/Hokkaido/WZ68/2012 (H13N2), isolated from the same area in the same year in our surveillance, were genetically and antigenically analyzed with 10 representative H13 strains including a prototype strain, A/gull/Maryland/704/1977 (H13N6). The HA genes of H13 AIVs were phylogenetically divided into 3 groups (I, II, and III). A/duck/Hokkaido/W345/2012 (H13N2) was genetically classified into Group III. This virus was distinct from a prototype strain, A/gull/Maryland/704/1977 (H13N6), and the virus, A/duck/Hokkaido/WZ68/2012 (H13N2), both belonging to Group I. Antigenic analysis indicated that the viruses of Group I were antigenically closely related to those of Group II, but distinct from those of Group III, including A/duck/Hokkaido/W345/2012 (H13N2). In summary, our study indicates that H13 AIVs have undergone antigenic diversification in nature.
  • Twabela AT, Tshilenge GM, Sakoda Y, Okamatsu M, Bushu E, Kone P, Wiersma L, Zamperin G, Drago A, Zecchin B, Monne I
    Emerging infectious diseases 24 (7) 1371 - 1374 1080-6040 2018/07 [Refereed][Not invited]
  • A. Shibata, T. Hiono, H. Fukuhara, R. Sumiyoshi, A. Ohkawara, K. Matsuno, M. Okamatsu, H. Osaka, Y. Sakoda
    Transboundary and Emerging Diseases 65 (2) 465 - 475 1865-1682 2018/04/01 [Refereed][Not invited]
     
    The transportation of poultry and related products for international trade contributes to transboundary pathogen spread and disease outbreaks worldwide. To prevent pathogen incursion through poultry products, many countries have regulations about animal health and poultry product quarantine. However, in Japan, animal products have been illegally introduced into the country in baggage and confiscated at the airport. Lately, the number of illegally imported poultry and the incursion risk of transboundary pathogens through poultry products have been increasing. In this study, we isolated avian influenza viruses (AIVs) from raw poultry products illegally imported to Japan by international passengers. Highly (H5N1 and H5N6) and low (H9N2 and H1N2) pathogenic AIVs were isolated from raw chicken and duck products carried by flight passengers. H5 and H9 isolates were phylogenetically closely related to viruses isolated from poultry in China, and haemagglutinin genes of H5N1 and H5N6 isolates belonged to clades 2.3.2.1c and 2.3.4.4, respectively. Experimental infections of H5 and H9 isolates in chickens and ducks demonstrated pathogenicity and tissue tropism to skeletal muscles. To prevent virus incursion by poultry products, it is important to encourage the phased cleaning based on the disease control and eradication and promote the reduction in contamination risk in animal products.
  • S. Sekiguchi, P. Presi, R. Omori, K. Staerk, M. Schuppers, N. Isoda, Y. Yoshikawa, T. Umemura, H. Nakayama, Y. Fujii, Y. Sakoda
    Transboundary and Emerging Diseases 65 (1) e135 - e144 1865-1682 2018/02/01 [Refereed][Not invited]
     
    Bovine viral diarrhoea virus (BVDV) infection in cattle can result in growth retardation, reduced milk production, reproductive disorders and death. Persistently infected animals are the primary source of infection. In Hokkaido, Japan, all cattle entering shared pastures in summer are vaccinated before movement for disease control. Additionally, these cattle may be tested for BVDV and culled if positive. However, the effectiveness of this control strategy aiming to reduce the number of BVDV-infected animals has not been assessed. The aim of this study was to evaluate the effectiveness of various test-and-cull and/or vaccination strategies on BVDV control in dairy farms in two districts of Hokkaido, Nemuro and Hiyama. A stochastic model was developed to compare the different control strategies over a 10-year period. The model was individual-based and simulated disease dynamics both within and between herds. Parameters included in the model were obtained from the literature, the Hokkaido government and the Japanese Ministry of Agriculture, Forestry and Fisheries. Nine different scenarios were compared as follows: no control, test-and-cull strategies based on antigen testing of either calves or only cattle entering common pastures, vaccination of all adult cattle or only cattle entering shared pastures and combinations thereof. The results indicate that current strategies for BVDV control in Hokkaido slightly reduced the number of BVDV-infected animals however, alternative strategies such as testing all calves and culling any positives or vaccinating all susceptible adult animals dramatically reduced those. To our knowledge, this is the first report regarding the comparison of the effectiveness between the current strategies in Hokkaido and the alternative strategies for BVDV control measures.
  • Takashi Kozasa, Shiho Torii, Ken Ichiro Kameyama, Makoto Nagai, Norikazu Isoda, Mai Shiokawa, Hiroshi Aoki, Masatoshi Okamatsu, Hideto Sekiguchi, Akito Saito, Yoshihiro Sakoda
    Japanese Journal of Veterinary Research 66 (4) 317 - 324 0047-1917 2018 
    The purpose of this study was to investigate the prevalence of HoBi-like viruses in Japan and evaluate the immune response induced by bovine viral diarrhea virus (BVDV) vaccines available in Japan. No HoBi-like viruses were detected by RT-PCR and virus isolation in cattle sera collected in Japan between 2012 and 2017. Nevertheless, neutralizing antibody titers against HoBi-like viruses ranged from < 2 to 4,096, demonstrating cross-reactivity to HoBi-like viruses in cattle infected (naturally or vaccinated) with BVDV-1 and BVDV-2. These results suggest that continuous vaccination with both BVDV-1 and BVDV-2 contributes to the control of HoBi-like viruses in Japan.
  • H. Takaki, S. Kure, H. Oshiumi, Y. Sakoda, T. Suzuki, A. Ainai, H. Hasegawa, M. Matsumoto, T. Seya
    Mucosal Immunology 11 (1) 82 - 96 1935-3456 2018/01/01 [Refereed][Not invited]
     
    Intranasal inoculation with influenza hemagglutinin subunit with polyinosine-polycytidylic (polyI:C), a synthetic analog for double-stranded RNA, enhances production of vaccine-specific immunoglobulin (Ig) A, which is superior to IgG in prophylactic immunity. The mechanism whereby polyI:C skews to IgA production in the nasal-associated lymph tissue (NALT) was investigated in mouse models. Nasally instilled polyI:C was endocytosed into CD103 + dendritic cells (DCs) and induced T-cell activation, including interferon (IFN)-β 3 production. According to knockout mouse studies, polyI:C activated the Toll-like receptor 3 signal via the adapter TICAM-1 (also called TRIF), that mainly caused T-cell-dependent IgA production. Nasal CD103 + DCs activated transforming growth factor-β signaling and activation-induced cytidine deaminase upon polyI:C stimulation. IgA rather than IgG production was impaired in Batf3 mice, where CD103 + DCs are defective. Genomic recombination occurred in IgA-producing cells in association with polyI:C-stimulated DCs and nasal microenvironment. PolyI:C induced B-cell-activating factor expression and weakly triggered T-cell-independent IgA production. PolyI:C simultaneously activated mitochondrial antiviral signaling and then type I IFN receptor pathways, which only minimally participated in IgA production. Taken together, CD103 + DCs in NALT are indispensable for the adjuvant activity of polyI:C in enhancing vaccine-specific IgA induction and protective immunity against influenza viruses.
  • Mizuho Suzuki, Masatoshi Okamatsu, Yuri Fujimoto, Takahiro Hiono, Keita Matsuno, Hiroshi Kida, Yoshihiro Sakoda
    Japanese Journal of Veterinary Research 66 (1) 29 - 41 0047-1917 2018 [Refereed][Not invited]
     
    The H10N8 influenza virus became a threat to public health when cases of fatal infections were identified in China in 2013 and 2014. Thus, genetic and antigenic characterization of H10 influenza viruses and development of an appropriate vaccine are essential to prepare for a future pandemic by H10 influenza viruses. However, current information regarding these properties of H10 influenza viruses circulating in birds is limited. In this study, genetic analysis of H10 influenza viruses revealed that the viruses recently circulating in wild birds in East Asia are genetically close to human H10N8 influenza viruses. Furthermore, the antigenicity of H10 influenza viruses was stable among the viruses circulating in birds. An inactivated vaccine was prepared from A/duck/Mongolia/245/2015 (H10N3), which is genetically and antigenically close to the human H10 influenza viruses. The vaccine induced sufficient neutralizing antibodies against homologous and heterologous viruses in mice. The inactivated vaccine induced protective immunity sufficient to reduce the impact of challenges with A/duck/Hokkaido/W87/2007 (H10N2), which is pathogenic strain in mice. This study demonstrates that the inactivated whole virus particle vaccine prepared from viruses isolated from wild birds would be useful against a future pandemic influenza by H10 influenza viruses.
  • Tomokazu Tamura, Takasuke Fukuhara, Takuro Uchida, Chikako Ono, Hiroyuki Mori, Asuka Sato, Yuzy Fauzyah, Toru Okamoto, Takeshi Kurosu, Yin Xiang Setoh, Michio Imamura, Norbert Tautz, Yoshihiro Sakoda, Alexander A. Khromykh, Kazuaki Chayama, Yoshiharu Matsuura
    Journal of Virology 92 (2) 1098-5514 2018/01/01 [Refereed][Not invited]
     
    The family Flaviviridae consists of four genera, Flavivirus, Pestivirus, Pegivirus, and Hepacivirus, and comprises important pathogens of human and animals. Although the construction of recombinant viruses carrying reporter genes encoding fluorescent and bioluminescent proteins has been reported, the stable insertion of foreign genes into viral genomes retaining infectivity remains difficult. Here, we applied the 11-amino-acid subunit derived from NanoLuc luciferase to the engineering of the Flaviviridae viruses and then examined the biological characteristics of the viruses. We successfully generated recombinant viruses carrying the split-luciferase gene, including dengue virus, Japanese encephalitis virus, hepatitis C virus (HCV), and bovine viral diarrhea virus. The stability of the viruses was confirmed by five rounds of serial passages in the respective susceptible cell lines. The propagation of the recombinant luciferase viruses in each cell line was comparable to that of the parental viruses. By using a purified counterpart luciferase protein, this split-luciferase assay can be applicable in various cell lines, even when it is difficult to transduce the counterpart gene. The efficacy of antiviral reagents against the recombinant viruses could be monitored by the reduction of luciferase expression, which was correlated with that of viral RNA, and the recombinant HCV was also useful to examine viral dynamics in vivo. Taken together, our findings indicate that the recombinant Flaviviridae viruses possessing the split NanoLuc luciferase gene generated here provide powerful tools to understand viral life cycle and pathogenesis and a robust platform to develop novel antivirals against Flaviviridae viruses.
  • D. -H. Chu, M. A. Stevenson, L. V. Nguyen, N. Isoda, S. M. Firestone, T. N. Nguyen, L. T. Nguyen, K. Matsuno, M. Okamatsu, H. Kida, Y. Sakoda
    TRANSBOUNDARY AND EMERGING DISEASES 64 (6) 1991 - 1999 1865-1674 2017/12 [Refereed][Not invited]
     
    In Vietnam, live bird markets are found in most populated centres, providing the means by which fresh poultry can be purchased by consumers for immediate consumption. Live bird markets are aggregation points for large numbers of poultry, and therefore, it is common for a range of avian influenza viruses to be mixed within live bird markets as a result of different poultry types and species being brought together from different geographical locations. We conducted a cross-sectional study in seven live bird markets in four districts of Thua Thien Hue Province in August and December, 2014. The aims of this study were to (i) document the prevalence of avian influenza in live bird markets (as measured by virus isolation); and (ii) quantify individual bird-, seller- and market-level characteristics that rendered poultry more likely to be positive for avian influenza virus at the time of sale. A questionnaire soliciting details of knowledge, attitude and avian influenza practices was administered to poultry sellers in study markets. At the same time, swabs and faecal samples were collected from individual poultry and submitted for isolation of avian influenza virus. The final data set comprised samples from 1,629 birds from 83 sellers in the seven live bird markets. A total of 113 birds were positive for virus isolation; a prevalence of 6.9 (95% CI 5.8-8.3) avian influenza virus-positive birds per 100 birds submitted for sale. After adjusting for clustering at the market and individual seller levels, none of the explanatory variables solicited in the questionnaire were significantly associated with avian influenza virus isolation positivity. The proportions of variance at the individual market, seller and individual bird levels were 6%, 48% and 46%, respectively. We conclude that the emphasis of avian influenza control efforts in Vietnam should be at the individual seller level as opposed to the market level.
  • Mizuho Suzuki, Masatoshi Okamatsu, Takahiro Hiono, Keita Matsuno, Yoshihiro Sakoda
    JOURNAL OF VETERINARY MEDICAL SCIENCE 79 (11) 1815 - 1821 0916-7250 2017/11 [Refereed][Not invited]
     
    H2N2 influenza virus caused a pandemic starting in 1957 but has not been detected in humans since 1968. Thus, most people are immunologically naive to viruses of the H2 subtype. In contrast, H2 influenza viruses are continually isolated from wild birds, and H2N3 viruses were isolated from pigs in 2006. H2 influenza viruses could cause a pandemic if re-introduced into humans. In the present study, a vaccine against H2 influenza was prepared as an effective control measure against a future human pandemic. A/duck/Hokkaido/162/2013 (H2N1), which showed broad antigenic cross-reactivity, was selected from the candidate H2 influenza viruses recently isolated from wild birds in Asian countries. Sufficient neutralizing antibodies against homologous and heterologous viruses were induced in mice after two subcutaneous injections of the inactivated whole virus particle vaccine. The inactivated vaccine induced protective immunity sufficient to reduce the impact of challenges with A/swine/Missouri/2124514/2006 (H2N3). This study demonstrates that the inactivated whole virus particle vaccine prepared from an influenza virus library would be useful against a future H2 influenza pandemic.
  • Tumenjargal Sharav, Satoru Konnai, Nyamsuren Ochirkhuu, Erdene T. S. Ochir, Hirohisa Mekata, Yoshihiro Sakoda, Takashi Umemura, Shiro Murata, Tungalag Chultemdorj, Kazuhiko Ohashi
    JOURNAL OF VETERINARY MEDICAL SCIENCE 79 (11) 1884 - 1888 0916-7250 2017/11 [Refereed][Not invited]
     
    The genetic characterization and actual prevalence of EIAV in Mongolian horse in the disease endemic region is currently unknown. Here, 11 of 776 horse serum samples from four Mongolian provinces tested positive on agar gel immunodiffusion test. Genomic DNA extracted from all seropositive samples was subjected to nested PCR assay. Among these, three samples tested positive with nested PCR assay and were identified by sequencing analysis based on long termination repeat and tat gene of the virus. Two of the three sequences were identical, with 94.0% identity with the third. These two independent Mongolian EIAV sequences were retained functional motifs, with no dramatic changes but some variability in the U5 region; they were clustered with genotypes from European countries but not with those from China, U.S.A., or Japan.
  • Lam Thanh Nguyen, Tatsuya Nishi, Shintaro Shichinohe, Duc-Huy Chu, Takahiro Hiono, Keita Matsuno, Masatoshi Okamatsu, Hiroshi Kida, Yoshihiro Sakoda
    VIROLOGY 510 252 - 261 0042-6822 2017/10 [Refereed][Not invited]
     
    Vaccination-primed immunity in poultry has been suggested for selection of antigenically drifted highly pathogenic avian influenza viruses (HPAIVs). In this study, we performed two consecutive passage studies of an H5N1 HPAIV in vaccinated chickens, namely, study-I and study-II, to select antigenic variants under immune pressure from the vaccination. In study-I, nine consecutive passages of a wild-type H5N1 HPAIV were carried out in chickens vaccinated with the homologous challenge strain. Antigenically drifted variants with mutations at position 179 in the hemagglutinin (HA) were selected after three passages. Similarly, in study-II, a vaccination-mediated antigenic variant isolated in study-I was used as the vaccine and challenge strain to confirm further antigenic drift after updating the vaccine; after the third passage, additional antigenic variants with a mutation at position 256 in the HA were selected. Thus, our study demonstrated the contribution of vaccination in the selection of antigenic variants of H5 HPAIVs in chickens.
  • Engineering of Small Reporter-Tagged Flaviviridae Viruses Applicable to Antiviral Screening and in vivo Dynamics
    Tomokazu Tamura, Takasuke Fukuhara, Akatuski Saito, Takuro Uchida, Chikako Ono, Hiroyuki Mori, Toru Okamoto, Takeshi Kurosu, Norbert Tautz, Yoshihiro Sakoda, Tatuso Shioda, Kazuaki Chayama, Yoshiharu Matsuura
    2017/09 [Not refereed][Not invited]
  • Takahiro Hiono, Masatoshi Okamatsu, Keita Matsuno, Atsushi Haga, Ritsuko Iwata, Lam Thanh Nguyen, Mizuho Suzuki, Yuto Kikutani, Hiroshi Kida, Manabu Onuma, Yoshihiro Sakoda
    MICROBIOLOGY AND IMMUNOLOGY 61 (9) 387 - 397 0385-5600 2017/09 [Refereed][Not invited]
     
    On 15 November 2016, a black swan that had died in a zoo in Akita prefecture, northern Japan, was strongly suspected to have highly pathogenic avian influenza (HPAI); an HPAI virus (HPAIV) belonging to the H5N6 subtype was isolated from specimens taken from the bird. After the initial report, 230 cases of HPAI caused by H5N6 viruses from wild birds, captive birds, and domestic poultry farms were reported throughout the country during the winter season. In the present study, 66 H5N6 HPAIVs isolated from northern Japan were further characterized. Phylogenetic analysis of the hemagglutinin gene showed that the H5N6 viruses isolated in northern Japan clustered into Group C of Clade 2.3.4.4 together with other isolates collected in Japan, Korea and Taiwan during the winter season of 2016-2017. The antigenicity of the Japanese H5N6 isolate differed slightly from that of HPAIVs isolated previously in Japan and China. The virus exhibited high pathogenicity and a high replication capacity in chickens, whereas virus growth was slightly lower in ducks compared with that of an H5N8 HPAIV isolate collected in Japan in 2014. Comprehensive analyses of Japanese isolates, including those from central, western, and southern Japan, as well as rapid publication of this information are essential for facilitating greater control of HPAIVs.
  • Marina Gulyaeva, Kirill Sharshov, Mizuho Suzuki, Ivan Sobolev, Yoshihiro Sakoda, Alexander Alekseev, Mariya Sivay, Lidia Shestopalova, Michael Shchelkanov, Alexander Shestopalov
    JOURNAL OF VETERINARY MEDICAL SCIENCE 79 (8) 1461 - 1465 0916-7250 2017/08 [Refereed][Not invited]
     
    Thirty-two muskrats (Ondatra zibethicus) were captured for surveillance of avian influenza virus in wild waterfowl and mammals near Lake Chany, Western Siberia, Russia. A/muskrat/Russia/63/2014 (H2N2) was isolated from an apparently healthy muskrat using chicken embryos. Based on phylogenetic analysis, the hemagglutinin and neuraminidase genes of this isolate were classified into the Eurasian avian-like influenza virus clade and closely related to low pathogenic avian influenza viruses (LPAIVs) isolated from wild water birds in Italy and Sweden, respectively. Other internal genes were also closely related to LPAIVs isolated from Eurasian wild water birds. Results suggest that interspecies transmission of LPAIVs from wild water birds to semiaquatic mammals occurs, facilitating the spread and evolution of LPAIVs in wetland areas of Western Siberia.
  • Lam Thanh Nguyen, Kazunari Nakaishi, Keiko Motojima, Ayako Ohkawara, Erina Minato, Junki Maruyama, Takahiro Hiono, Keita Matsuno, Masatoshi Okamatsu, Takashi Kimura, Ayato Takada, Hiroshi Kida, Yoshihiro Sakoda
    PLOS ONE 12 (8) e0182228  1932-6203 2017/08 [Refereed][Not invited]
     
    Highly pathogenic avian influenza viruses (HPAIVs) of H5 subtype have persistently caused outbreaks in domestic poultry and wild birds worldwide and sporadically infected humans. Rapid and accurate diagnosis is one of the key strategies for the control of H5 HPAIVs. However, the sensitivity of the diagnosis of H5 HPAIVs has gradually reduced due to extensive antigenic variation during their evolution. Particularly, the previously developed immunochromatographic diagnosis kit for H5 viruses, Linjudge Flu A/H5, exhibits reduced detection of H5 HPAIVs isolated in recent years. In the present study, we established a new advanced H5 rapid immunochromatographic detection kit (New Linjudge Flu A/H5) by a combination of two anti-H5 hemagglutinin monoclonal antibodies, A64/1 previously applied in the Linjudge Flu A/H5 and A32/2, a novel monoclonal antibody generated from a clade 2.3.4.4 H5 HPAIV. The new kit broadly detected all classical and recent H5 influenza viruses and showed a higher specificity and sensitivity than the original Linjudge Flu A/H5 with recently circulating H5 HPAIVs. Furthermore, the applicability of the New Linjudge Flu A/H5 was demonstrated by detecting antigens from the swabs and tissue homogenates of naturally infected birds and experimentally infected chickens with H5N6 HPAIVs belonging to the genetic clade 2.3.4.4. Our study, therefore, can provide an effective point-of-care rapid antigen detection kit for the surveillance of H5 avian influenza viruses and as a prompt countermeasure against the current widespread of the clade 2.3.4.4 H5 HPAIVs in domestic and wild birds.
  • Norikazu Isoda, Akihiro Asano, Michiru Ichijo, Shiho Wakamori, Hiroshi Ohno, Kazuhiko Sato, Hirokazu Okamoto, Shigeru Nakao, Hajime Kato, Kazuma Saito, Naoki Ito, Akira Usui, Hiroaki Takayama, Yoshihiro Sakoda
    JOURNAL OF VETERINARY MEDICAL SCIENCE 79 (7) 1172 - 1181 0916-7250 2017/07 [Refereed][Not invited]
     
    A scenario tree model was developed to propose efficient bovine viral diarrhea (BVD) control measures. The model used field data in eastern Hokkaido where the risk of BVDV infection in cattle has been reduced by an eradication program including mass vaccination, individual tests prior to communal pasture grazing, herd screening tests using bulk milk, and outbreak investigations of newly infected herds. These four activities were then used as hypothesized control measures in the simulation. In each simulation, the numbers of cattle infected persistently and transiently with BVDV detected by clinical manifestations and diagnosis tests and of missed by all of the diagnosis tests were calculated, and the numbers were used as indicators to be compared for the efficacy of the control measures. The model outputs indicated that the adoption of mass vaccination decreased the number of missed BVD cattle, although it did not increase the number of detected BVD cattle. Under implementation of mass vaccination, the efficacy of individual tests on selected 20% of the young and adult cattle was equal to that of the herd screening test performed in all the herds. When the virus prevalence or the number of sensitive animals becomes low, the efficacy of herd screening test was superior to one of individual tests. Considering the model outputs together, the scenario tree model developed in the present study was useful to compare the efficacy of the control measures for BVD.
  • Takasuke Fukuhara, Tomokazu Tamura, Chikako Ono, Mai Shiokawa, Hiroyuki Mori, Kentaro Uemura, Satomi Yamamoto, Takeshi Kurihara, Toru Okamoto, Ryosuke Suzuki, Kentaro Yoshii, Takeshi Kurosu, Manabu Igarashi, Hiroshi Aoki, Yoshihiro Sakoda, Yoshiharu Matsuura
    PLOS PATHOGENS 13 (6) e1006475  1553-7366 2017/06 [Refereed][Not invited]
     
    Amphipathic alpha-helices of exchangeable apolipoproteins have shown to play crucial roles in the formation of infectious hepatitis C virus (HCV) particles through the interaction with viral particles. Among the Flaviviridae members, pestivirus and flavivirus possess a viral structural protein E-rns or a non-structural protein 1 (NS1) as secretory glycoproteins, respectively, while Hepacivirus including HCV has no secretory glycoprotein. In case of pestivirus replication, the C-terminal long amphipathic alpha-helices of E-rns are important for anchoring to viral membrane. Here we show that host-derived apolipoproteins play functional roles similar to those of virally encoded E-rns and NS1 in the formation of infectious particles. We examined whether E-rns and NS1 could compensate for the role of apolipoproteins in particle formation of HCV in apolipoprotein B (ApoB) and ApoE double-knockout Huh7 (BE-KO), and nonhepatic 293T cells. We found that exogenous expression of either E-rns or NS1 rescued infectious particle formation of HCV in the BE-KO and 293T cells. In addition, expression of apolipoproteins or NS1 partially rescued the production of infectious pestivirus particles in cells upon electroporation with an E-rns-deleted non-infectious RNA. As with exchangeable apolipoproteins, the C-terminal amphipathic alpha-helices of E-rns play the functional roles in the formation of infectious HCV or pestivirus particles. These results strongly suggest that the host-and virus-derived secretory glycoproteins have overlapping roles in the viral life cycle of Flaviviridae, especially in the maturation of infectious particles, while E-rns and NS1 also participate in replication complex formation and viral entry, respectively. Considering the abundant hepatic expression and liver-specific propagation of these apolipoproteins, HCV might have evolved to utilize them in the formation of infectious particles through deletion of a secretory viral glycoprotein gene.
  • Bazarragchaa Enkhbold, Munkhduuren Shatar, Shiho Wakamori, Tomokazu Tamura, Takahiro Hiono, Keita Matsuno, Masatoshi Okamatsu, Takashi Umemura, Batchuluun Damdinjav, Yoshihiro Sakoda
    VIRUS GENES 53 (3) 418 - 425 0920-8569 2017/06 [Refereed][Not invited]
     
    Classical swine fever (CSF), a highly contagious viral disease affecting domestic and wild pigs in many developing countries, is now considered endemic in Mongolia, with 14 recent outbreaks in 2007, 2008, 2011, 2012, 2014, and 2015. For the first time, CSF viruses isolated from these 14 outbreaks were analyzed to assess their molecular epidemiology and pathogenicity in pigs. Based on the nucleotide sequences of their 5'-untranslated region, isolates were phylogenetically classified as either sub-genotypes 2.1b or 2.2, and the 2014 and 2015 isolates, which were classified as 2.1b, were closely related to isolates from China and Korea. In addition, at least three different viruses classified as 2.1b circulated in Mongolia. Experimental infection of the representative isolate in 2014 demonstrated moderate pathogenicity in 4-week-old pigs, with relatively mild clinical signs. Understanding the diversity of circulating CSF viruses gleans insight into disease dynamics and evolution, and may inform the design of effective CSF control strategies in Mongolia.
  • Ayako Ohkawara, Masatoshi Okamatsu, Makoto Ozawa, Duc-Huy Chu, Lam Thanh Nguyen, Takahiro Hiono, Keita Matsuno, Hiroshi Kida, Yoshihiro Sakoda
    MICROBIOLOGY AND IMMUNOLOGY 61 (5) 149 - 158 0385-5600 2017/05 [Refereed][Not invited]
     
    H5 highly pathogenic avian influenza viruses (HPAIV) have spread in both poultry and wild birds since late 2003. Continued circulation of HPAIV in poultry in several regions of the world has led to antigenic drift. In the present study, we analyzed the antigenic properties of H5 HPAIV isolated in Asia using four neutralizing mAbs recognizing hemagglutinin, which were established using A/chicken/Kumamoto/1-7/2014 (H5N8), belonging to clade 2.3.4.4 and also using polyclonal antibodies. Viruses of clades 1.1, 2.3.2.1, 2.3.4, and 2.3.4.4 had different reactivity patterns to the panel of mAbs, thereby indicating that the antigenicity of the viruses of clade 2.3.4.4 were similar but differed from the other clades. In particular, the antigenicity of the viruses of clade 2.3.4.4 differed from those of the viruses of clades 2.3.4 and 2.3.2.1, which suggests that the recent H5 HPAIV have further evolved antigenically divergent. In addition, reactivity of antiserum suggests that the antigenicity of viruses of clade 2.3.4.4 differed slightly among groups A, B, and C. Vaccines are still used in poultry in endemic countries, so the antigenicity of H5 HPAIV should be monitored continually to facilitate control of avian influenza. The panel of mAbs established in the present study will be useful for detecting antigenic drift in the H5 viruses that emerge from the current strains.
  • Akihiro Nakatsukasa, Koji Kuruma, Masatoshi Okamatsu, Takahiro Hiono, Mizuho Suzuki, Keita Matsuno, Hiroshi Kida, Takayoshi Oyamada, Yoshihiro Sakoda
    VACCINE 35 (21) 2855 - 2861 0264-410X 2017/05 [Refereed][Not invited]
     
    Transdermal vaccination using a microneedle (MN) confers enhanced immunity compared with subcutaneous (SC) vaccination. Here we developed a novel dissolving MN patch for the influenza vaccine. The potencies of split virion and whole virus particle (WVP) vaccines prepared from A/Puerto Rico/8/1934 (H1N1) and A/duck/Hokkaido/Vac-3/2007 (H5N1), respectively, were evaluated. MN vaccination induced higher neutralizing antibody responses than SC vaccination in mice. Moreover, MN vaccination with a lower dose of antigens conferred protective immunity against lethal challenges of influenza viruses than SC vaccination in mice. These results suggest that the WVP vaccines administered using MN are an effective combination for influenza vaccine to be further validated in humans. (C) 2017 Elsevier Ltd. All rights reserved.
  • Masatoshi Okamatsu, Makoto Ozawa, Kosuke Soda, Hiroki Takakuwa, Atsushi Haga, Takahiro Hiono, Aya Matsuu, Yuko Uchida, Ritsuko Iwata, Keita Matsuno, Masakazu Kuwahara, Toshiyo Yabuta, Tatsufumi Usui, Hiroshi Ito, Manabu Onuma, Yoshihiro Sakoda, Takehiko Saito, Koichi Otsuki, Toshihiro Ito, Hiroshi Kida
    EMERGING INFECTIOUS DISEASES 23 (4) 691 - 695 1080-6040 2017/04 [Refereed][Not invited]
     
    Highly pathogenic avian influenza viruses (HPAIVs) A(H5N6) were concurrently introduced into several distant regions of Japan in November 2016. These viruses were classified into the genetic clade 2.3.4.4c and were genetically closely related to H5N6 HPAIVs recently isolated in South Korea and China. In addition, these HPAIVs showed further antigenic drift.
  • Masanori Kobayashi, Makoto Kodama, Takeshi Noshi, Ryu Yoshida, Takushi Kanazu, Naoki Nomura, Kosuke Soda, Norikazu Isoda, Masatoshi Okamatsu, Yoshihiro Sakoda, Yoshinori Yamano, Akihiko Sato, Hiroshi Kida
    ANTIVIRAL RESEARCH 139 41 - 48 0166-3542 2017/03 [Refereed][Not invited]
     
    High morbidity and mortality associated with human cases of highly pathogenic avian influenza (HPAI) viruses, including H5N1 influenza virus, have been reported. The purpose of the present study was to evaluate the antiviral effects of peramivir against HPAI viruses. In neuraminidase (NA) inhibition and virus replication inhibition assays, peramivir showed strong inhibitory activity against H5N1, H7N1 and H7N7 HPAI viruses with sub-nanomolar activity in enzyme assays. In H5N1 viruses containing the NA H275Y mutation, the antiviral activity of peramivir against the variant was lower than that against the wild-type. Evaluation of the in vivo antiviral activity showed that a single intravenous treatment of peramivir (10 mg/kg) prevented lethality in mice infected with wild-type H5N1 virus and also following infection with H5N1 virus with the H275Y mutation after a 5 day administration of peramivir (30 mg/kg). Furthermore, mice injected with peramivir showed low viral titers and low levels of proinflammatory cytokines in the lungs. These results suggest that peramivir has therapeutic activity against HPAI viruses even if the virus harbors the NA H275Y mutation. (C) 2016 Elsevier B.V. All rights reserved.
  • Misako Nakayama, Yasushi Itoh, Shintaro Shichinohe, Rumi Nakabayashi, Hirohito Ishigaki, Yoshihiro Sakoda, Quynh Mai Le, Yoshihiro Kawaoka, Hiroshi Kida, Kazumasa Ogasawara
    VACCINE 35 (7) 1008 - 1017 0264-410X 2017/02 [Refereed][Not invited]
     
    The efficacy and detrimental effect of mucosal vaccination with an inactivated influenza vaccine were examined in a macaque model by intranasal administration with small amounts of inactivated whole virus particles and challenge by a human-derived H5N1 highly pathogenic avian influenza virus infection. Repeated nasal inoculation with the whole particle vaccine of an inactivated virus, A/duck/Hokkaido/Vac-3/2007 (H5N1) (Vac-3), induced antigen-specific IgA and IgG antibody production in nasal swabs and plasma. Vac-3-specific IgE production was also found in the nasal swabs. Nasal vaccination with Vac-3 induced broader cross-clade neutralization activity than did subcutaneous vaccination. After challenge infection, repeated nasal vaccination almost completely prevented the propagation of virus in the upper and lower airways and protected cynomolgus macaques from viral pneumonia by induction of IgA-producing B cells in the lungs. On the other hand, eosinophil clusters were observed in the lungs of vaccinated macaques. Although Vac-3-specific IgE antibody and IL-13 levels were decreased after infection compared to those before infection and no anaphylaxis in vaccinated macaques was detected after challenge infection, our results suggest that we have to pay attention to potential allergic responses at repeated nasal vaccination, especially in people who have an airway allergy. (C) 2017 Elsevier Ltd. All rights reserved.
  • Takasuke Fukuhara, Tomokazu Tamura, Chikako Ono, Mai Shiokawa, Hiroyuki Mori, Kentaro Uemura, Satomi Yamamoto, Takeshi Kurihara, Toru Okamoto, Ryosuke Suzuki, Kentaro Yoshii, Takeshi Kurosu, Manabu Igarashi, Hiroshi Aoki, Yoshihiro Sakoda, Yoshiharu Matsuura
    PLoS Pathogens 13 (6) 1553-7374 2017 [Refereed][Not invited]
     
    Amphipathic α-helices of exchangeable apolipoproteins have shown to play crucial roles in the formation of infectious hepatitis C virus (HCV) particles through the interaction with viral particles. Among the Flaviviridae members, pestivirus and flavivirus possess a viral structural protein Ernsor a non-structural protein 1 (NS1) as secretory glycoproteins, respectively, while Hepacivirus including HCV has no secretory glycoprotein. In case of pestivirus replication, the C-terminal long amphipathic α-helices of Ernsare important for anchoring to viral membrane. Here we show that host-derived apolipoproteins play functional roles similar to those of virally encoded Ernsand NS1 in the formation of infectious particles. We examined whether Ernsand NS1 could compensate for the role of apolipoproteins in particle formation of HCV in apolipoprotein B (ApoB) and ApoE double-knockout Huh7 (BE-KO), and non-hepatic 293T cells. We found that exogenous expression of either Ernsor NS1 rescued infectious particle formation of HCV in the BE-KO and 293T cells. In addition, expression of apolipoproteins or NS1 partially rescued the production of infectious pestivirus particles in cells upon electroporation with an Erns-deleted non-infectious RNA. As with exchangeable apolipoproteins, the C-terminal amphipathic α-helices of Ernsplay the functional roles in the formation of infectious HCV or pestivirus particles. These results strongly suggest that the host- and virus-derived secretory glycoproteins have overlapping roles in the viral life cycle of Flaviviridae, especially in the maturation of infectious particles, while Ernsand NS1 also participate in replication complex formation and viral entry, respectively. Considering the abundant hepatic expression and liver-specific propagation of these apolipoproteins, HCV might have evolved to utilize them in the formation of infectious particles through deletion of a secretory viral glycoprotein gene.
  • Misako Nakayama, Hiroichi Ozaki, Yasushi Itoh, Kosuke Soda, Hirohito Ishigaki, Masatoshi Okamatsu, Yoshihiro Sakoda, Chun-Ho Park, Hideaki Tsuchiya, Hiroshi Kida, Kazumasa Ogasawara
    PATHOLOGY INTERNATIONAL 66 (12) 678 - 686 1320-5463 2016/12 [Refereed][Not invited]
     
    H9N2 avian influenza virus causes sporadic human infection. Since humans do not possess acquired immunity specific to this virus, we examined the pathogenicity of an H9N2 virus isolated from a human and then analyzed protective effects of a vaccine in cynomolgus macaques. After intranasal challenge with A/Hong Kong/1073/1999 (H9N2) (HK1073) isolated from a human patient, viruses were isolated from nasal and tracheal swabs in unvaccinated macaques with mild fever and body weight loss. A formalin-inactivated H9N2 whole particle vaccine derived from our virus library was subcutaneously inoculated to macaques. Vaccination induced viral antigen-specific IgG and neutralization activity in sera. After intranasal challenge with H9N2, the virus was detected only the day after inoculation in the vaccinated macaques. Without vaccination, many bronchus-associated lymphoid tissues (BALTs) were formed in the lungs after infection, whereas the numbers of BALTs were smaller and the cytokine responses were weaker in the vaccinated macaques than those in the unvaccinated macaques. These findings indicate that the H9N2 avian influenza virus HK1073 is pathogenic in primates but seems to cause milder symptoms than does H7N9 influenza virus as found in our previous studies and that a formalin-inactivated H9N2 whole particle vaccine induces protective immunity against H9N2 virus.
  • Fumihiko Yasui, Yasushi Itoh, Ai Ikejiri, Masahiro Kitabatake, Nobuo Sakaguchi, Keisuke Munekata, Shintaro Shichinohe, Yukiko Hayashi, Hirohito Ishigaki, Misako Nakayama, Yoshihiro Sakoda, Hiroshi Kida, Kazumasa Ogasawara, Michinori Kohara
    SCIENTIFIC REPORTS 6 37915  2045-2322 2016/11 [Refereed][Not invited]
     
    H5N1 highly pathogenic avian influenza (H5N1 HPAI) virus causes elevated mortality compared with seasonal influenza viruses like H1N1 pandemic influenza (H1N1 pdm) virus. We identified a mechanism associated with the severe symptoms seen with H5N1 HPAI virus infection. H5N1 HPAI virus infection induced a decrease of dendritic cell number in the splenic extrafollicular T-cell zone and impaired formation of the outer layers of B-cell follicles, resulting in insufficient levels of antibody production after infection. However, in animals vaccinated with a live recombinant vaccinia virus expressing the H5 hemagglutinin, infection with H5N1 HPAI virus induced parafollicular dendritic cell accumulation and efficient antibody production. These results indicate that a recombinant vaccinia encoding H5 hemagglutinin gene does not impair dendritic cell recruitment and can be a useful vaccine candidate.
  • Samantha J. Lycett, Rogier Bodewes, Anne Pohlmann, Jill Banks, Krisztian Banyai, Maciej F. Boni, Ruth Bouwstra, Andrew C. Breed, Ian H. Brown, Hualan Chen, Adam Dan, Thomas J. DeLiberto, Nguyen Diep, Marius Gilbert, Sarah Hill, Hon S. Ip, Chang Wen Ke, Hiroshi Kida, Mary Lea Killian, Marion P. Koopmans, Jung-Hoon Kwon, Dong-Hun Lee, Youn Jeong Lee, Lu Lu, Isabella Monne, John Pasick, Oliver G. Pybus, Andrew Rambaut, Timothy P. Robinson, Yoshihiro Sakoda, Siamak Zohari, Chang-Seon Song, David E. Swayne, Mia Kim Torchetti, Hsiang-Jung Tsai, Ron A. M. Fouchier, Martin Beer, Mark Woolhouse, Thijs Kuiken
    SCIENCE 354 (6309) 213 - 217 0036-8075 2016/10 [Refereed][Not invited]
     
    Avian influenza viruses affect both poultry production and public health. A subtype H5N8 (clade 2.3.4.4) virus, following an outbreak in poultry in South Korea in January 2014, rapidly spread worldwide in 2014-2015. Our analysis of H5N8 viral sequences, epidemiological investigations, waterfowl migration, and poultry trade showed that long-distance migratory birds can play a major role in the global spread of avian influenza viruses. Further, we found that the hemagglutinin of clade 2.3.4.4 virus was remarkably promiscuous, creating reassortants with multiple neuraminidase subtypes. Improving our understanding of the circumpolar circulation of avian influenza viruses in migratory waterfowl will help to provide early warning of threats from avian influenza to poultry, and potentially human, health.
  • フラビウイルス科ウイルスの粒子産生における分泌性糖タンパク質の役割
    Tomokazu Tamura, Takasuke Fukuhara, Mai Shiokawa, Chikako Ono, Satomi Yamamoto, Hiroyuki Mori, Takeshi Kurihara, Toru Okamoto, Hiroshi Aoki, Yoshihiro Sakoda, Yoshiharu Matsuura
    2016/10 [Not refereed][Not invited]
  • The roles of secretory glycoproteins in viral particle formation in family Flaviviridae
    Tomokazu Tamura, Takasuke Fukuhara, Mai Shiokawa, Chikako Ono, Satomi Yamamoto, Hiroyuki Mori, Takeshi Kurihara, Toru Okamoto, Hiroshi Aoki, Yoshihiro Sakoda, Yoshiharu Matsuura
    2016/10 [Refereed][Not invited]
  • Viral secretory glycoproteins of Flaviviridae virus have similar roles with apolipoproteins on the formation of infectious HCV particles
    Takasuke Fukuhara, Tomokazu Tamura, Mai Shiokawa, Chikako Ono, Satomi Yamamoto, Hiroyuki Mori, Takeshi Kurihara, Kentaro Uemura, Toru Okamoto, Hiroshi Aoki, Yoshihiro Sakoda, Yoshiharu Matsuura
    2016/10 [Refereed][Not invited]
  • Taisuke Horimoto, Takahiro Hiono, Hirohisa Mekata, Tomoha Odagiri, Zhihao Lei, Tomoya Kobayashi, Junzo Norimine, Yasuo Inoshima, Hirokazu Hikono, Kenji Murakami, Reiichiro Sato, Hironobu Murakami, Masahiro Sakaguchi, Kazunori Ishii, Takaaki Ando, Kounosuke Otomaru, Makoto Ozawa, Yoshihiro Sakoda, Shin Murakami
    PLOS ONE 11 (9) e0163828  1932-6203 2016/09 [Refereed][Not invited]
     
    Cattle are major reservoirs of the provisionally named influenza D virus, which is potentially involved in the bovine respiratory disease complex. Here, we conducted a serological survey for the influenza D virus in Japan, using archived bovine serum samples collected during 2010-2016 from several herds of apparently healthy cattle in various regions of the country. We found sero-positive cattle across all years and in all the prefectural regions tested, with a total positivity rate of 30.5%, although the positivity rates varied among regions (13.5-50.0%). There was no significant difference in positivity rates for Holstein and Japanese Black cattle. Positivity rates tended to increase with cattle age. The herds were clearly divided into two groups: those with a high positive rate and those with a low (or no) positive rate, indicating that horizontal transmission of the virus occurs readily within a herd. These data demonstrate that bovine influenza D viruses have been in circulation for at least 5 years countrywide, emphasizing its ubiquitous distribution in the cattle population of Japan.
  • Masatoshi Okamatsu, Takahiro Hiono, Hiroshi Kida, Yoshihiro Sakoda
    VETERINARY JOURNAL 215 82 - 86 1090-0233 2016/09 [Refereed][Not invited]
     
    The diagnosis of influenza A virus infections in poultry or wild birds is difficult due to variations in the pathogenicity of the viruses in different avian hosts and also the antigenic and genetic diversity of the virus, particularly the recent H5 highly pathogenic avian influenza viruses. A classical standard laboratory technique is virus isolation prior to subtyping and pathotyping. This diagnostic technique is crucial for further virological analyses, particularly during an initial outbreak; however, delays in diagnosis have thwarted effective disease control in recent years. Recent developments in molecular biological techniques provide an accelerated diagnosis. Such technologies, which include real-time reverse transcriptase PCR, isothermal nucleic acid amplification, next-generation sequencing and immunochromatography, contribute to simpler and more rapid diagnosis. The advantages of each of these diagnostic techniques should be considered for effective control of avian influenza. (C) 2016 Elsevier Ltd. All rights reserved.
  • Duc-Huy Chu, Masatoshi Okamatsu, Keita Matsuno, Takahiro Hiono, Kohei Ogasawara, Lam Thanh Nguyen, Long Van Nguyen, Tien Ngoc Nguyen, Thuy Thu Nguyen, Dong Van Pham, Dang Hoang Nguyen, Tho Dang Nguyen, Thanh Long To, Hung Van Nguyen, Hiroshi Kida, Yoshihiro Sakoda
    VETERINARY MICROBIOLOGY 192 194 - 203 0378-1135 2016/08 [Refereed][Not invited]
     
    A total of 3,045 environmental samples and oropharyngeal and cloacal swabs from apparently healthy poultry have been collected at three live bird markets (LBMs) at which practices were applied to reduce avian influenza (AI) virus transmission (intervention LBMs) and six conventional LBMs (non-intervention LBMs) in Thua Thien Hue province in 2014 to evaluate the efficacy of the intervention LBMs. The 178 AI viruses, including H3 (19 viruses), H4 (2), H5 (8), H6 (30), H9 (114), and H11 (5), were isolated from domestic ducks, muscovy ducks, chickens, and the environment. The prevalence of AI viruses in intervention LBMs (6.1%; 95% CI: 5.0-7.5) was similar to that in non-intervention LBMs (5.6%; 95% CI: 4.5-6.8; x(2) = 0.532; df = 1; P = 0.53) in the study area. Eight H5N6 highly pathogenic avian influenza (HPAI) viruses were isolated from apparently healthy ducks, muscovy ducks, and an environmental sample in an intervention LBM. The hemagglutinin genes of the H5N6 HPAI viruses belonged to the genetic Glade 23.4.4, and the antigenicity of the H5N6 HPAI viruses differed from the H5N1 HPAI viruses previously circulating in Vietnam. Phylogenetic and antigenic analyses of the H6 and H9 viruses isolated in both types of LBMs revealed that they were closely related to the viruses isolated from domestic birds in China, Group II of H6 viruses and Y280 lineage of H9 viruses. These results indicate that the interventions currently applied in LBMs are insufficient to control AI. A risk analysis should be conducted to identify the key factors contributing to Al virus prevalence in intervention LBMs. (C) 2016 Elsevier B.V. All rights reserved.
  • Hiromichi Mitake, Yuji Fujii, Makoto Nagai, Naoto Ito, Kota Okadera, Kazuma Okada, Kento Nakagawa, Mai Kishimoto, Tetsuya Mizutani, Katsunori Okazaki, Yoshihiro Sakoda, Ayato Takada, Makoto Sugiyama
    JOURNAL OF GENERAL VIROLOGY 97 (8) 1818 - 1822 0022-1317 2016/08 [Refereed][Not invited]
     
    Ljungan virus (LV) has been isolated/detected from rodents in a limited area including European countries and the USA. In this study, we isolated an LV strain from faecal samples of wild birds that had been collected in Japan, and determined the nearly complete sequence of the genome. Sequence analyses showed that the isolate possesses an LV-like genomic organization: 5UTR-VP0-VP3-VP1-2A1-2A2-2B-2C-3A-3B-3C-3D-3UTR. Phylogenetic and similarity analyses based on the VP1 region indicated that the strain constitutes a novel genotype within LV. In addition, we identified species origin of the faeces as gull species by using the DNA barcoding technique. These data suggested that the novel LV strain infected a gull species, in which the virus had not been identified. Taken together, this study has provided the first evidence of the presence of a novel LV in Japan, highlighting the possibility of LV infection in birds.
  • Masatoshi Okamatsu, Yurie Motohashi, Takahiro Hiono, Tomokazu Tamura, Kazuki Nagaya, Keita Matsuno, Yoshihiro Sakoda, Hiroshi Kida
    ARCHIVES OF VIROLOGY 161 (8) 2235 - 2242 0304-8608 2016/08 [Refereed][Not invited]
     
    Influenza viruses isolated from wild ducks do not replicate in chickens. This fact is not explained solely by the receptor specificity of the hemagglutinin (HA) from such viruses for target host cells. To investigate this restriction in host range, the fusion activities of HA molecules from duck and chicken influenza viruses were examined. Influenza viruses A/duck/Mongolia/54/2001 (H5N2) (Dk/MNG) and A/chicken/Ibaraki/1/2005 (H5N2) (Ck/IBR), which replicate only in their primary hosts, were used. The optimal pH for membrane fusion of Ck/IBR was 5.9, higher than that of Dk/MNG at 4.9. To assess the relationship between the optimal pH for fusion and the host range of avian influenza viruses, the optimal pH for fusion of 55 influenza virus strains isolated from ducks and chickens was examined. No correlation was found between the host range and optimal pH for membrane fusion by the viruses, and this finding applied also to the H5N1 highly pathogenic avian influenza viruses. The optimal pH for membrane fusion for avian influenza viruses was shown to not necessarily be correlated with their host range or pathogenicity in ducks and chickens.
  • Shintaro Shichinohe, Yasushi Itoh, Misako Nakayama, Hiroichi Ozaki, Kosuke Soda, Hirohito Ishigaki, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida, Kazumasa Ogasawara
    VIROLOGY 493 31 - 38 0042-6822 2016/06 [Refereed][Not invited]
     
    The outbreak of H7N9 low pathogenic avian influenza viruses in China has attracted attention to H7 influenza virus infection in humans. Since we have shown that the pathogenicity of H1N1 and H5N1 influenza viruses in macaques was almost the same as that in humans, we compared the pathogenicities of H7 avian influenza viruses in cynomolgus macaques via intranasal and conjunctival inoculation, which mimics natural infection in humans. H7N9 virus, as well as H7N7 highly pathogenic avian influenza virus, showed more efficient replication and higher pathogenicity in macaques than did H7N1 and H7N3 highly pathogenic avian influenza viruses. These results are different from pathogenicity in chickens as reported previously. Therefore, our results obtained in macaques help to estimate the pathogenicity of H7 avian influenza viruses in humans. (C) 2016 Elsevier Inc. All rights reserved.
  • Hiroshi Yamada, Satoshi Nagase, Kazuo Takahashi, Yoshihiro Sakoda, Hiroshi Kida, Shigefumi Okamoto
    ANTIVIRAL RESEARCH 129 81 - 92 0166-3542 2016/05 [Refereed][Not invited]
     
    The most effective drugs available to treat influenza are neuraminidase (NA) inhibitors, which provide important additional measures for the control of influenza virus infections. However, since the emergence of NA inhibitor-resistant viruses may compromise the clinical utility of this class of anti-influenza agents, it is very important to develop new anti-influenza agents which target a different region in NA responsible for its sensitivity from that for NA inhibitors and could be used to treat NA inhibitors resistant isolates. The oligodeoxynucleotide D35, multimerized and aggregated, suppressed replication of influenza A viruses except A/WSN/33 (WSN). The suppressive viral replication by D35 depended on G-terad and multimer formation. The range of the suppressive viral replication at the late stage, including virus assembly and release from infected cells, was much larger than that at the initial stage, viral attachment and entry. D35 suppressed NA activity of influenza A viruses. Furthermore, replacing the NA gene of A/Puerto Rico/8/34 (PR8), in which viral replication was inhibited by D35 at the late stage, with the NA gene from WSN, in which viral replication was not inhibited, eliminated the D35-dependent suppression. D35 showed an additive anti-influenza effect with oseltamivir. It was also effective in vivo. These results suggest that the influenza virus NA mainly contributse to the D35-suppressible virus release from infected cells at the late stage. In addition, because administration of D35 into the virus-infected mice suppressed viral replication and weight loss, clinical application of D35 could be considered. (C) 2016 Elsevier B.V. All rights reserved.
  • Kanae Shiokawa, Chandika D. Gamage, Nobuo Koizumi, Yoshihiro Sakoda, Kenta Shimizu, Yoshimi Tsuda, Kumiko Yoshimatsu, Jiro Arikawa
    JOURNAL OF VETERINARY MEDICAL SCIENCE 78 (2) 221 - 230 0916-7250 2016/02 [Refereed][Not invited]
     
    The applicability of the recombinant LipL32 for serodiagnosis of leptospiral infection in field rodents was assessed in this study. An immunodominant region of LipL32 was determined by monoclonal antibodies, and then, truncated LipL32 (tLipL32) was designed to contain the region (87-188th amino acid). The tLipL32 was compared between two recombinant expression hosts Escherichia coli and Pichia pastoris in ELISA. With field rat sera, tLipL32 expressed by P. pastoris (tLipL32p) had high antigenicity without background reactions, while tLipL32 expressed by E. coli (tLipL32e) showed high background reactions, which were reduced by pre-adsorption of sera with E. coli. To evaluate tLipL32-ELISA, field rat sera were tentatively divided into a Leptospira infection positive (12 sera) and a negative group (12 sera) based on the results from flaB gene PCR of kidney samples and WB with whole Leptospira cell. Consequently, the sensitivity of tLipL32p-ELISA for field rat sera was 83%. A similar result was obtained from tLipL32e-ELISA with adsorbed sera, (92%). However, sensitivity of tLipL32e-ELISA using sera without an adsorption treatment was 50%. Regardless of the expression host, tLipL32-ELISA had 100% specificity and sensitivity in experimentally infected laboratory rats. These results suggest that recombinant LipL32 expressed by P pastoris is more applicable for serodiagnosis in field rats due to a lack of background reaction.
  • Takahiro Hiono, Masatoshi Okamatsu, Manabu Igarashi, Ryan McBride, Robert P. de Vries, Wenjie Peng, James C. Paulson, Yoshihiro Sakoda, Hiroshi Kida
    ARCHIVES OF VIROLOGY 161 (2) 307 - 316 0304-8608 2016/02 [Refereed][Not invited]
     
    Influenza viruses isolated from ducks are rarely able to infect chickens; it is therefore postulated that these viruses need to adapt in some way to be able to be transmitted to chickens in nature. Previous studies revealed that sialyl Lewis X (3'SLeX), which is fucosylated alpha 2,3 sialoside, was predominantly detected on the epithelial cells of the chicken trachea, whereas this glycan structure is not found in the duck intestinal tract. To clarify the mechanisms of the interspecies transmission of influenza viruses between ducks and chickens, we compared the receptor specificity of low-pathogenic avian influenza viruses isolated from these two species. Glycan-binding analysis of the recombinant hemagglutinin (HA) of a chicken influenza virus, A/chicken/Ibaraki/1/2005 (H5N2), revealed a binding preference to alpha 1,3 fucosylated sialosides. On the other hand, the HA of a duck influenza virus, A/duck/Mongolia/54/2001 (H5N2) (Dk/MNG), particularly bound to non-fucosylated alpha 2,3 sialosides such as 3'-sialyllactosamine (3'SLacNAc). Computational analysis along with binding analysis of the mutant HAs revealed that this glycan-binding specificity of the HA was determined by amino acid residues at positions 222 and 227. Inconsistent with the glycan-binding specificity of the recombinant HA protein, virions of Dk/MNG bound to both 3'SLacNAc and 3'SLeX. Glycan-binding analysis in the presence of a neuraminidase (NA) inhibitor revealed that the NA conferred binding to 3'SLeX to virions of Dk/MNG. The present results reveal the molecular basis of the interaction between fucosylated alpha 2,3 sialosides and influenza viruses.
  • Takahiro Hiono, Keita Matsuno, Kotaro Tuchiya, Zhifeng Lin, Masatoshi Okamatsu, Yoshihiro Sakoda
    Genome Announcements 4 (5) 2169-8287 2016 [Refereed][Not invited]
     
    Here, we report the complete genome sequence of the avian paramyxovirus serotype 5 strain APMV-5/budgerigar/Japan/TI/75, which was determined using the Illumina MiSeq platform. The determined sequence shares 97% homology and similar genetic features with the previously known genome sequence of avian paramyxovirus serotype 5 strain APMV-5/budgerigar/Japan/Kunitachi/74.
  • Takahiro Hiono, Masatoshi Okamatsu, Naoki Yamamoto, Kohei Ogasawara, Mayumi Endo, Saya Kuribayashi, Shintaro Shichinohe, Yurie Motohashi, Duc-Huy Chu, Mizuho Suzuki, Takaya Ichikawa, Tatsuya Nishi, Yuri Abe, Keita Matsuno, Kazuyuki Tanaka, Tsutomu Tanigawa, Hiroshi Kida, Yoshihiro Sakoda
    VETERINARY MICROBIOLOGY 182 108 - 115 0378-1135 2016/01 [Refereed][Not invited]
     
    Highly pathogenic avian influenza viruses (HPAIVs) have spread in both poultry and wild birds. Determining transmission routes of these viruses during an outbreak is essential for the control of avian influenza. It has been widely postulated that migratory ducks play crucial roles in the widespread dissemination of HPAIVs in poultry by carrying viruses along with their migrations; however close contacts between wild migratory ducks and poultry are less likely in modern industrial poultry farming settings. Therefore, we conducted experimental infections of HPAIVs and low pathogenic avian influenza viruses (LPAIVs) to chickens, domestic ducks, tree sparrows, jungle crows, and black rats to evaluate their roles in virus transmission. The results showed that chickens, ducks, sparrows, and crows were highly susceptible to HPAIV infection. Significant titers of virus were recovered from the sparrows and crows infected with HPAIVs, which suggests that they potentially play roles of transmission of HPAIVs to poultry. In contrast, the growth of LPAIVs was limited in each of the animals tested compared with that of HPAIVs. The present results indicate that these common synanthropes play some roles in influenza virus transmission from wild birds to poultry. (C) 2015 Elsevier B.V. All rights reserved.
  • Yuri Abe, Tomokazu Tamura, Shiho Torii, Shiho Wakamori, Makoto Nagai, Kazuya Mitsuhashi, Junki Mine, Yuri Fujimoto, Naofumi Nagashima, Fumi Yoshino, Yukihiko Sugita, Takushi Nomura, Masatoshi Okamatsu, Hiroshi Kida, Yoshihiro Sakoda
    JOURNAL OF VETERINARY MEDICAL SCIENCE 78 (1) 61 - 70 0916-7250 2016/01 [Refereed][Not invited]
     
    In our previous study, we genetically analyzed bovine viral diarrhea viruses (BVDVs) isolated from 2000 to 2006 in Japan and reported that subgenotype 1b viruses were predominant. In the present study, 766 BVDVs isolated from 2006 to 2014 in Hokkaido, Japan, were genetically analyzed to understand recent epidemics. Phylogenetic analysis based on nucleotide sequences of the 5'-untranslated region of viral genome revealed that 766 isolates were classified as genotype 1 (BVDV-1; 544 isolates) and genotype 2 (BVDV-2; 222). BVDV-1 isolates were further divided into BVDV-la (93), 1b (371) and 1c (80) subgenotypes, and all BVDV-2 isolates were grouped into BVDV-2a subgenotype (222). Further comparative analysis was performed with BVDV-1a, 1b and 2a viruses isolated from 2001 to 2014. Phylogenetic analysis based on nucleotide sequences of the viral glycoprotein E2 gene, a major target of neutralizing antibodies, revealed that BVDV-1a, 1b and 2a isolates were further classified into several clusters. Cross-neutralization tests showed that BVDV-1b isolates were antigenically different from BVDV-1a isolates, and almost BVDV-1a, 1b and 2a isolates were antigenically similar among each subgenotype and each E2 cluster. Taken together, BVDV-1b viruses are still predominant, and BVDV-2a viruses have increased recently in Hokkaido, Japan. Field isolates of BVDV-1a, 1b and 2a show genetic diversity on the E2 gene with antigenic conservation among each subgenotype during the last 14 years.
  • Koichiro Gamoh, Mari Nakamizo, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida, Shoko Suzuki
    JOURNAL OF VETERINARY MEDICAL SCIENCE 78 (1) 139 - 142 0916-7250 2016/01 [Refereed][Not invited]
     
    H5 highly pathogenic avian influenza (HPAI) viruses have spread worldwide, and antigenic variants of different clades have been selected. In this study, the national stockpiled vaccine prepared from A/duck/HoldcaidoNac-1/2004 (H5N1) strain was evaluated for the protective efficacy against H5N8 HPAI virus isolated in Kumamoto prefecture, Japan, in April 2014. In the challenge test, all of the vaccinated chickens survived without showing any clinical signs and reduced virus shedding. It was concluded that the present stockpiled vaccine was effective against the H5N8 HPAI virus.
  • Intracellular membrane association of classical swine fever virus NS4B is critical for viral RNA replication
    Tomokazu Tamura, Nicolas Ruggli, Masatoshi Okamatsu, Keita Matsuno, Yoshihiro Sakoda
    2015/11 [Refereed][Not invited]
  • 豚コレラウイルスの病原性発現の分子基盤
    田村友和, Nicolas Ruggli, 岡松正敏, 松野啓太, 迫田義博
    2015/11 [Refereed][Not invited]
  • Apolipoproteins and viral secretory glycoproteins participate in the infectious particle formation of Flaviviridae
    Takasuke Fukuhara, Tomokazu Tamura, Mai Shiokawa, Chikako Ono, Satomi Yamamoto, Hiroyuki Mori, Takeshi Kurihara, Toru Okamoto, Hiroshi Aoki, Yoshihiro Sakoda, Yoshiharu Matsuura
    2015/11 [Refereed][Not invited]
  • フラビウイルス科に共通した小胞体膜結合因子を介した粒子産生機構の解析
    福原 崇介, 田村 友和, 塩川 舞, 小野 慎子, 山本 聡美, 森 寛行, 栗原 健, 岡本 徹, 青木 博史, 迫田 義博, 松浦 善治
    2015/11 [Refereed][Not invited]
  • Host or virus derived secretory membrane binding proteins are involved in formation of infectious Flavivirus particles
    Takasuke Fukuhara, Tomokazu Tamura, Mai Shiokawa, Chikako Ono, Satomi Yamamoto, Hiroyuki Mori, Takeshi Kurihara, Puig-Basagoiti Francesc, Toru Okamoto, Hiroshi Aoki, Yoshihiro Sakoda, Yoshiharu Matsuura
    2015/11 [Refereed][Not invited]
  • Naganori Nao, Masahiro Kajihara, Rashid Manzoor, Junki Maruyama, Reiko Yoshida, Mieko Muramatsu, Hiroko Miyamoto, Manabu Igarashi, Nao Eguchi, Masahiro Sato, Tatsunari Kondoh, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida, Ayato Takada
    PLOS ONE 10 (9) e0137989  1932-6203 2015/09 [Refereed][Not invited]
     
    Two highly pathogenic avian influenza virus strains, A/duck/Hokkaido/WZ83/2010 ( H5N1) (WZ83) and A/duck/Hokkaido/WZ101/2010 (H5N1) (WZ101), which were isolated from wild ducks in Japan, were found to be genetically similar, with only two amino acid differences in their M1 and PB1 proteins at positions 43 and 317, respectively. We found that both WZ83 and WZ101 caused lethal infection in chickens but WZ101 killed them more rapidly than WZ83. Interestingly, ducks experimentally infected with WZ83 showed no or only mild clinical symptoms, whereas WZ101 was highly lethal. We then generated reassortants between these viruses and found that exchange of the M gene segment completely switched the pathogenic phenotype in both chickens and ducks, indicating that the difference in the pathogenicity for these avian species between WZ83 and WZ101 was determined by only a single amino acid in the M1 protein. It was also found that WZ101 showed higher pathogenicity than WZ83 in mice and that WZ83, whose M gene was replaced with that of WZ101, showed higher pathogenicity than wild-type WZ83, although this reassortant virus was not fully pathogenic compared to wild-type WZ101. These results suggest that the amino acid at position 43 of the M1 protein is one of the factors contributing to the pathogenicity of H5N1 highly pathogenic avian influenza viruses in both avian and mammalian hosts.
  • Tomokazu Tamura, Nicolas Ruggli, Naofumi Nagashima, Masatoshi Okamatsu, Manabu Igarashi, Junki Mine, Martin A. Hofmann, Matthias Liniger, Artur Summerfield, Hiroshi Kida, Yoshihiro Sakoda
    JOURNAL OF GENERAL VIROLOGY 96 (9) 2623 - 2635 0022-1317 2015/09 [Refereed][Not invited]
     
    Classical swine fever virus (CSFV) causes a highly contagious disease in pigs that can range from a severe haemorrhagic fever to a nearly unapparent disease, depending on the virulence of the virus strain. Little is known about the viral molecular determinants of CSFV virulence. The nonstructural protein NS4B is essential for viral replication. However, the roles of CSFV NS4B in viral genome replication and pathogenesis have not yet been elucidated. NS4B of the GPE(-) vaccine strain and of the highly virulent Eystrup strain differ by a total of seven amino acid residues, two of which are located in the predicted trans-membrane domains of NS4B and were described previously to relate to virulence, and five residues clustering in the N-terminal part. In the present study, we examined the potential role of these five amino acids in modulating genome replication and determining pathogenicity in pigs. A chimeric low virulent GPE(-)-derived virus carrying the complete Eystrup NS4B showed enhanced pathogenicity in pigs. The in vitro replication efficiency of the NS4B chimeric GPE- replicon was significantly higher than that of the replicon carrying only the two Eystrup-specific amino acids in NS4B. In silico and in vitro data suggest that the N-terminal part of NS4B forms an amphipathic a-helix structure. The N-terminal NS4B with these five amino acid residues is associated with the intracellular membranes. Taken together, this is the first gain-of-function study showing that the N-terminal domain of NS4B can determine CSFV genome replication in cell culture and viral pathogenicity in pigs.
  • Takahiro Hiono, Ayako Ohkawara, Kohei Ogasawara, Masatoshi Okamatsu, Tomokazu Tamura, Duc-Huy Chu, Mizuho Suzuki, Saya Kuribayashi, Shintaro Shichinohe, Ayato Takada, Hirohito Ogawa, Reiko Yoshida, Hiroko Miyamoto, Naganori Nao, Wakako Furuyama, Junki Maruyama, Nao Eguchi, Gerelmaa Ulziibat, Bazarragchaa Enkhbold, Munkhduuren Shatar, Tserenjav Jargalsaikhan, Selenge Byambadorj, Batchuluun Damdinjav, Yoshihiro Sakoda, Hiroshi Kida
    VIRUS GENES 51 (1) 57 - 68 0920-8569 2015/08 [Refereed][Not invited]
     
    Migratory water birds are the natural reservoir of influenza A viruses. H5 and H7 influenza viruses are isolated over the world and also circulate among poultry in Asia. In 2010, two H5N1 highly pathogenic avian influenza viruses (HPAIVs) were isolated from fecal samples of water birds on the flyway of migration from Siberia, Russia to the south in Hokkaido, Japan. H7N9 viruses are sporadically isolated from humans and circulate in poultry in China. To monitor whether these viruses have spread in the wild bird population, we conducted virological surveillance of avian influenza in migratory water birds in autumn from 2010 to 2014. A total of 8103 fecal samples from migratory water birds were collected in Japan and Mongolia, and 350 influenza viruses including 13 H5 and 19 H7 influenza viruses were isolated. A phylogenetic analysis revealed that all isolates are genetically closely related to viruses circulating among wild water birds. The results of the antigenic analysis indicated that the antigenicity of viruses in wild water birds is highly stable despite their nucleotide sequence diversity but is distinct from that of HPAIVs recently isolated in Asia. The present results suggest that HPAIVs and Chinese H7N9 viruses were not predominantly circulating in migratory water birds; however, continued monitoring of H5 and H7 influenza viruses both in domestic and wild birds is recommended for the control of avian influenza.
  • Yasushi Itoh, Shintaro Shichinohe, Misako Nakayama, Manabu Igarashi, Akihiro Ishii, Hirohito Ishigaki, Hideaki Ishida, Naoko Kitagawa, Takako Sasamura, Masanori Shiohara, Michiko Doi, Hideaki Tsuchiya, Shinichiro Nakamura, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida, Kazumasa Ogasawara
    ANTIMICROBIAL AGENTS AND CHEMOTHERAPY 59 (8) 4962 - 4973 0066-4804 2015/08 [Refereed][Not invited]
     
    The number of patients infected with H7N9 influenza virus has been increasing since 2013. We examined the efficacy of neuraminidase (NA) inhibitors and the efficacy of a vaccine against an H7N9 influenza virus, A/Anhui/1/2013 (H7N9), isolated from a patient in a cynomolgus macaque model. NA inhibitors (oseltamivir and peramivir) barely reduced the total virus amount because of the emergence of resistant variants with R289K or 1219T in NA [residues 289 and 219 in N9 of A/Anhui/1/2013 (H7N9) correspond to 292 and 222 in N2, respectively] in three of the six treated macaques, whereas subcutaneous immunization of an inactivated vaccine derived from A/duck/Mongolia/119/2008 (H7N9) prevented propagation of A/Anhui/1/2013 (H7N9) in all vaccinated macaques. The percentage of macaques in which variant H7N9 viruses with low sensitivity to the NA inhibitors were detected was much higher than that of macaques in which variant H5N1 highly pathogenic influenza virus was detected after treatment with one of the NA inhibitors in our previous study. The virus with R289K in NA was reported in samples from human patients, whereas that with 1219T in NA was identified for the first time in this study using macaques, though no variant H7N9 virus was reported in previous studies using mice. Therefore, the macaque model enables prediction of the frequency of emerging H7N9 virus resistant to NA inhibitors in vivo. Since H7N9 strains resistant to NA inhibitors might easily emerge compared to other influenza viruses, monitoring of the emergence of variants is required during treatment of H7N9 influenza virus infection with NA inhibitors.
  • 豚コレラウイルス非構造蛋白NS4Bの機能と病原性に及ぼす影響
    田村友和, Nicolas Ruggli, 長島尚史, 岡松正敏, Artur Summerfield, 松野啓太, 喜田宏, 迫田義博
    2015/07 [Refereed][Not invited]
  • Junki Mine, Tomokazu Tamura, Kazuya Mitsuhashi, Masatoshi Okamatsu, Sujira Parchariyanon, Wasana Pinyochon, Nicolas Ruggli, Jon-Duri Tratschin, Hiroshi Kida, Yoshihiro Sakoda
    JOURNAL OF GENERAL VIROLOGY 96 (7) 1746 - 1756 0022-1317 2015/07 [Refereed][Not invited]
     
    The viral protein N-pro is unique to the genus Pestivirus within the family Flaviviridae. After autocatalytic cleavage from the nascent polyprotein, N-pro suppresses type I IFN (IFN-alpha/beta) induction by mediating proteasomal degradation of IFN regulatory factor 3 (IRF-3). Previous studies found that the N-pro-mediated IRF-3 degradation was dependent of a TRASH domain in the C-terminal half of N-pro coordinating zinc by means of the amino acid residues 0112, 0134, D136 and C138. Interestingly, four classical swine fever virus (CSFV) isolates obtained from diseased pigs in Thailand in 1993 and 1998 did not suppress IFN-alpha/beta induction despite the presence of an intact TRASH domain. Through systematic analyses, it was found that an amino acid mutation at position 40 or mutations at positions 17 and 61 in the N-terminal half of N-pro of these four isolates were related to the lack of IRF-3-degrading activity. restoring a histidine at position 40 or both a proline at position 17 and a lysine at position 61 based on the sequence of a functional N-pro contributed to higher stability of the reconstructed N-pro compared with the N-pro from the Thai isolate. This led to enhanced interaction of N-pro with IRF-3 along with its degradation by the proteasome. The results of the present study revealed that amino acid residues in the N-terminal domain of N-pro are involved in the stability of N-pro, in interaction of N-pro with IRF-3 and subsequent degradation of IRF-3, leading to downregulation of IFN-alpha/beta production.
  • VIRAL GENETIC DETERMINANTS OF CLASSICAL SWINE FEVER VIRUS VIRULENCE
    Tomokazu Tamura, Nicolas Ruggli, Naofumi Nagashima, Masatoshi Okamatsu, Martin A. Hofmann, Hiroshi Kida, Autur Summerfield, Yoshihiro Sakoda
    2015/06 [Refereed][Not invited]
  • Takashi Kozasa, Yuri Abe, Kazuya Mitsuhashi, Tomokazu Tamura, Hiroshi Aoki, Masatoshi Ishimaru, Shigeyuki Nakamura, Masatoshi Okamatsu, Hiroshi Kida, Yoshihiro Sakoda
    JOURNAL OF VETERINARY MEDICAL SCIENCE 77 (5) 511 - 518 0916-7250 2015/05 [Refereed][Not invited]
     
    The Exaltation of Newcastle disease virus (END) phenomenon is induced by the inhibition of type I interferon in pestivirus-infected cells in vitro, via proteasomal degradation of cellular interferon regulatory factor (IRF)-3 with the property of the viral autoprotease protein N-pro. Reportedly, the amino acid residues in the zinc-binding TRASH motif of N-pro determine the difference in characteristics between END-phenomenon-positive (END) and END-phenomenon-negative (END-) classical swine fever viruses (CSFVs). However, the basic mechanism underlying this function in bovine viral diarrhea virus (BVDV) has not been elucidated from the genomic differences between END+ and END- viruses using reverse genetics till date. In the present study, comparison of complete genome sequences of a pair of END+ and END- viruses isolated from the same virus stock revealed that there were only four amino acid substitutions (D136G, I2623V, D3148G and D3502Y) between two viruses. Based on these differences, viruses with and without mutations at these positions were generated using reverse genetics. The END assay, measurements of induced type I interferon and IRF-3 detection in cells infected with these viruses revealed that the aspartic acid at position 136 in the zinc-binding TRASH motif of N-pro was required to inhibit the production of type I interferon via the degradation of cellular IRF-3, consistently with CSFV.
  • Tomokazu Tamura, Junki Mine, Shiho Torii, Yuri Fujimoto, Masatoshi Okamatsu, Yoshihiro Sakoda
    JOURNAL OF VETERINARY MEDICAL SCIENCE 77 (3) 341 - 343 0916-7250 2015/03 [Refereed][Not invited]
     
    A first isolation of border disease virus (BDV) in Japan was from a pig on a farm without keeping any ruminants. Our previous study showed that this BDV, termed the FNK2012-1 strain, replicated inefficiently in swine-derived cells compared with those of ruminant origin. Pigs inoculated with this virus showed neither clinical symptoms nor viremia. In this study, we evaluated the pathogenicity of the FNK2012-1 strain in sheep, its natural host. The inoculated sheep showed clinical symptoms and transient viremia. Seroconversion was observed in the inoculated sheep. These results suggest that the FNK2012-1 strain was introduced from sheep and has not yet adapted to swine. Therefore, surveillance of border disease in Japan is necessary among both the swine and ruminant populations.
  • Akira Sakurai, Katsuyoshi Takayama, Namiko Nomura, Naoki Kajiwara, Masatoshi Okamatsu, Naoki Yamamoto, Tsuruki Tamura, Jitsuho Yamada, Masako Hashimoto, Yoshihiro Sakoda, Yoshihiko Suda, Yukuharu Kobayashi, Hiroshi Kida, Futoshi Shibasaki
    PLOS ONE 10 (2) e0116715  1932-6203 2015/02 [Refereed][Not invited]
     
    Lateral flow tests also known as Immunochromatography (IC) is an antigen-detection method conducted on a nitrocellulose membrane that can be completed in less than 20 min. IC has been used as an important rapid test for clinical diagnosis and surveillance of influenza viruses, but the IC sensitivity is relatively low (approximately 60%) and the limit of detection (LOD) is as low as 10(3) pfu per reaction. Recently, we reported an improved IC assay using antibodies conjugated with fluorescent beads (fluorescent immunochromatography; FLIC) for subtyping H5 influenza viruses (FLIC-H5). Although the FLIC strip must be scanned using a fluorescent reader, the sensitivity (LOD) is significantly improved over that of conventional IC methods. In addition, the antibodies which are specific against the subtypes of influenza viruses cannot be available for the detection of other subtypes when the major antigenicity will be changed. In this study, we established the use of FLIC to type seasonal influenza A and B viruses (FLIC-AB). This method has improved sensitivity to 100-fold higher than that of conventional IC methods when we used several strains of influenza viruses. In addition, FLIC-AB demonstrated the ability to detect influenza type A and influenza type B viruses from clinical samples with high sensitivity and specificity (Type A: sensitivity 98.7% (74/75), specificity 100% (54/54), Type B: sensitivity 100% (90/90), specificity 98.2% (54/55) in nasal swab samples) in comparison to the results of qRT-PCR. And furthermore, FLIC-AB performs better in the detection of early stage infection (under 13h) than other conventional IC methods. Our results provide new strategies to prevent the early-stage transmission of influenza viruses in humans during both seasonal outbreaks and pandemics.
  • Kaoru Nishine, Hiroshi Aoki, Yoshihiro Sakoda, Akio Fukusho
    JOURNAL OF VETERINARY MEDICAL SCIENCE 76 (12) 1635 - 1639 0916-7250 2014/12 [Refereed][Not invited]
     
    Field isolates of BVDV which do not show the exaltation of Newcastle disease virus (END) phenomenon (END-) are rarely reported. In this study, 45 BVDV field isolates from cattle in Hokkaido prefecture in Japan were analyzed by the reverse plaque formation method, the END method and observation of cytopathic effects. END- virus was detected in 34 of 45 isolates (75.6%), although 35 of 45 field isolates contained END phenomenon positive virus as the predominant virus population. We propose that END- viruses are widely distributed in the field and that it is possible that the mixture of biologically distinct BVDV correlates with the appearance of disease in infected animals.
  • Kaoru Nishine, Hiroshi Aoki, Yoshihiro Sakoda, Akio Fukusho
    JOURNAL OF VETERINARY MEDICAL SCIENCE 76 (12) 1635 - 1639 0916-7250 2014/12 [Refereed][Not invited]
     
    Field isolates of BVDV which do not show the exaltation of Newcastle disease virus (END) phenomenon (END-) are rarely reported. In this study, 45 BVDV field isolates from cattle in Hokkaido prefecture in Japan were analyzed by the reverse plaque formation method, the END method and observation of cytopathic effects. END- virus was detected in 34 of 45 isolates (75.6%), although 35 of 45 field isolates contained END phenomenon positive virus as the predominant virus population. We propose that END- viruses are widely distributed in the field and that it is possible that the mixture of biologically distinct BVDV correlates with the appearance of disease in infected animals.
  • Akira Sakurai, Katsuyoshi Takayama, Namiko Nomura, Naoki Yamamoto, Yoshihiro Sakoda, Yukuharu Kobayashi, Hiroshi Kida, Futoshi Shibasaki
    JOURNAL OF VIROLOGICAL METHODS 209 62 - 68 0166-0934 2014/12 [Refereed][Not invited]
     
    Immunochromatography (IC) is an antigen-detection assay that plays an important role in the rapid diagnosis of influenza viruses because of its rapid turnaround and ease of use. Despite the usefulness of IC, the limit of detection of common IC kits is as high as 10(3)-10(4) plaque forming units (pfu) per reaction, resulting in their limited sensitivities. Early diagnosis within 24 h would provide more appropriate timing of treatment. In this study, a multi-colored NanoAct(TM) bead IC was established to detect seasonal influenza viruses. This method has approximately 10-fold higher sensitivity than that of colloidal gold or colored latex bead IC assays, and does not require specific instruments. More notably, NanoAct(Tm) bead IC can distinguish influenza A and B viruses from clinical samples with a straightforward readout composed of colored lines. Our results will provide new strategies for the diagnosis, treatment, and a chance to survey of influenza viruses in developing countries and in the field research. (C) 2014 Elsevier B.V. All rights reserved.
  • Ahmad M. Haredy, Hiroshi Yamada, Yoshihiro Sakoda, Masatoshi Okamatsu, Naoki Yamamoto, Takeshi Omasa, Yasuko Mori, Hiroshi Kida, Shigefumi Okamoto, Yoshinobu Okuno, Koichi Yamanishi
    JOURNAL OF GENERAL VIROLOGY 95 (Pt 11) 2365 - 2371 0022-1317 2014/11 [Refereed][Not invited]
     
    Whole-virus (WV) vaccines from influenza A/duck/Hokkaido/77 (H3N2), and its reassortant strains H3N4, H3N5 and H3N7, which have the same haemagglutinin (HA) gene but different neuraminidase (NA) genes, were prepared from our influenza virus library. Mice were intranasally immunized with equivalent doses of each vaccine (1-0.01 mu g per mouse). All of the mice that received the highest dose of each vaccine (1 mu g per mouse) showed equivalent high HA-inhibiting (HI) antibody titres and survived the H3N2 challenge viruses. However, mice that received lower doses of vaccine (0.1 or 0.01 mu g per mouse) containing a heterologous NA had lower survival rates than those given the H3N2-based vaccine. The lungs of mice challenged with H3N2 virus showed a significantly higher virus clearance rate when the vaccine contained the homologous NA (N2) versus a heterologous NA, suggesting that NA contributed to the protection, especially when the HI antibody level was low. These results suggested that, even if vaccines prepared for a possible upcoming pandemic do not induce sufficient HI antibodies, WV vaccines can still be effective through other matched proteins such as NA.
  • Tatsuya Nishi, Yoshihiro Sakoda, Masatoshi Okamatsu, Hiroshi Kida
    ARCHIVES OF VIROLOGY 159 (10) 2567 - 2574 0304-8608 2014/10 [Refereed][Not invited]
     
    H6 influenza viruses are prevalent in domestic and wild birds in Eurasian countries and have been isolated from pigs and a human. To prepare for an influenza pandemic, we have established an influenza virus library consisting of more than 1,300 influenza virus strains, including 144 combinations of 16 hemagglutinin and 9 neuraminidase subtypes. H6 viruses in the library were classified into Early, Group II, Group III, and W312 sublineages and the North America lineage on the basis of their phylogenetic features. Chicken antisera to A/duck/Hong Kong/960/1980 (H6N2) of the Early sublineage broadly reacted with viruses of different sublineages in a hemagglutinin inhibition test. A whole inactivated virus particle vaccine was prepared from A/duck/Hong Kong/960/1980 (H6N2) which was stocked in the influenza virus library. The potency of this vaccine against A/duck/Vietnam/OIE-0033/2012 (H6N2), which belongs to a different sublineage, was evaluated in mice. The test vaccine was sufficiently potent to induce an immune response that reduced the impact of disease caused by a challenge with A/duck/Vietnam/OIE-0033/2012 (H6N2) in mice. The present results indicate that the whole inactivated virus particle vaccine prepared from a virus strain in the influenza virus library is useful as a vaccine against pandemic influenza.
  • Takuji Kumagai, Tetsuo Nakayama, Yoshinobu Okuno, Tetsuo Kase, Naoko Nishimura, Takao Ozaki, Akiko Miyata, Eitaro Suzuki, Teruo Okafuji, Takao Okafuji, Hitoshi Ochiai, Nobuo Nagata, Hiroyuki Tsutsumi, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida, Toshiaki Ihara
    VIRAL IMMUNOLOGY 27 (8) 368 - 374 0882-8245 2014/10 [Refereed][Not invited]
     
    The 2009 pandemic H1N1 mainly affected adolescents and children, and most of the elderly in Japan escaped clinical illness. To clarify the role of humoral immunity in the infection, the time kinetics of hemagglutination inhibition (HI), neutralization (NT), and IgG subclass antibody response directed against influenza A(H1N1)pdm2009 were analyzed in three consecutive specimens obtained from 51 young adults and children (group 1) who contracted pandemic influenza and from 74 pediatric clinic employees (group 2) inoculated with pandemic monovalent vaccine. In group 1 patients, 6 and 30 patients had lower HI and NT antibody in the acute phase respectively. Thereafter, HI and NT antibody titers increased fourfold or more in 50 patients with peak response in the third specimens obtained four weeks after the onset. IgG1 in 45 patients, IgG3 in 18 patients, and IgG4 in 29 patients showed elevated responses. Forty (54%) and 70 (95%) subjects in group 2 had positive HI and NT antibodies in the prevaccination samples, with increased antibody responses in the follow-up peaking in the second specimens. Forty of those vaccinated had increased IgG1 responses peaking in the third specimens, whereas elevated IgG3 was observed in 22 recipients with the highest level in the second samples. IgG4 did not show any increase in subjects in group 2. A few participants showed an IgG2 response in both groups. An immunologically naive population contracted influenza with apparent clinical symptoms. However, already primed subjects through subclinical infection elicited the unique pattern of IgG subclass responses by vaccination, which differed from those of naive populations.
  • Makoto Kodama, Ryu Yoshida, Takahiro Hasegawa, Masaaki Izawa, Mitsutaka Kitano, Kaoru Baba, Takeshi Noshi, Takahiro Seki, Kenichi Okazaki, Masakatsu Tsuji, Takushi Kanazu, Hiroshi Kamimori, Tomoyuki Homma, Masanori Kobayashi, Yoshihiro Sakoda, Hiroshi Kida, Akihiko Sato, Yoshinori Yamano
    ANTIVIRAL RESEARCH 109 110 - 115 0166-3542 2014/09 [Refereed][Not invited]
     
    The purpose of this study was to investigate the relationship between pharmacokinetic (PK) parameters of intravenous (IV) peramivir and in vivo antiviral activity pharmacodynamic (PD) outcomes in a mouse model of influenza virus infection. Peramivir was administrated to mice in three dosing schedules; once, twice and four times after infection of A/WS/33 (H1N1). The survival rate at day 14 after virus infection was employed as the antiviral activity outcome for analysis. The relationship between day 14 survival and PK parameters, including area under the concentration-time curve (AUC), maximum concentration (C-max) and time that drug concentration exceeds IC95 (T>(IC95)), was estimated using a logistic regression model, and model fitness was evaluated by calculation of the Akaike information criterion (AIC) index. The AIC indices of AUC, C-max and T->IC95 were about 114, 151 and 124, respectively. The AIC of AUC and T->IC95 were smaller than that of C-max. Therefore, both AUC and T->IC95 were the PK parameters that correlated best with the antiviral activity of peramivir IV against influenza virus infection in mice. (C) 2014 Elsevier B.V. All rights reserved.
  • Walied Abdo, Mohie Haridy, Yuki Katou, Minami Goto, Toshio Mizoguchi, Yoshihiro Sakoda, Hiroki Sakai, Tokuma Yanai
    JOURNAL OF VETERINARY MEDICAL SCIENCE 76 (9) 1285 - 1290 0916-7250 2014/09 [Refereed][Not invited]
     
    In the winter of 2010-2011, an outbreak of highly pathogenic avian influenza virus (HPAIV) infection occurred in wild and domestic birds in Japan. Tufted ducks were found dead in an urban area of Toyota City, Koriyama, Fukushima Prefecture. Two tufted ducks were examined histopathologically, immunohistochemically and molecularly. Gross findings included marked dark-red clotted blood in the pectoral muscles and multifocal hemorrhages on the serous membranes. Microscopically, non-suppurative meningoencephalitis, multifocal to coalescing pancreatic necrosis and severe pulmonary congestion were observed. HPAIV antigen was detected in the malacic areas, neuronal, glial and ependymal cells, pulmonary capillary endothelial cells and epithelium of pulmonary bronchioles, necrotic pancreatic acini and degenerated cardiac myocytes. The HPAIV isolate was genetically classified into clade 2.3.2.1 group A. The broad distribution of virus antigen in brain and pulmonary tissues associated with HPAIV spontaneous infection in tufted ducks might be useful in understanding its pathogenesis in nature.
  • Makoto Nagai, Hiroshi Aoki, Yoshihiro Sakoda, Takashi Kozasa, Kaho Tominaga-Teshima, Junki Mine, Yuri Abe, Tomokazu Tamura, Tsubasa Kobayashi, Kaoru Nishine, Kentaro Tateishi, Yudai Suzuki, Mai Fukuhara, Keitaro Ohmori, Reiko Todaka, Kazuhiko Katayama, Tetsuya Mizutani, Shigeyuki Nakamura, Hiroshi Kida, Junsuke Shirai
    JOURNAL OF VETERINARY DIAGNOSTIC INVESTIGATION 26 (4) 547 - 552 1040-6387 2014/07 [Refereed][Not invited]
     
    In the current study, molecular, biological, and antigenic analyses were performed to characterize Border disease virus (BDV) strain FNK2012-1 isolated from a pig in 2012 in Japan. The complete genome comprises 12,327 nucleotides (nt), including a large open reading frame of 11,685 nt. Phylogenetic analysis revealed that FNK2012-1 was clustered into BDV genotype 1 with ovine strains. FNK2012-1 grew in porcine, bovine, and ovine primary cells and cell lines, but grew better in bovine and ovine cells than in porcine cells. Specific pathogen-free pigs inoculated with FNK2012-1 did not show any clinical signs. Noninoculated contact control pigs also did not show clinical signs and did not seroconvert. The results suggest that FNK2012-1 may be of ruminant origin and is poorly adapted to pigs. Such observations can provide important insights into evidence for infection and transmission of BDV, which may be of ruminant origin, among pigs.
  • Duc-Huy Chu, Yoshihiro Sakoda, Tatsuya Nishi, Takahiro Hiono, Shintaro Shichinohe, Masatoshi Okamatsu, Hiroshi Kida
    VACCINE 32 (28) 3473 - 3479 0264-410X 2014/06 [Refereed][Not invited]
     
    H7N9 influenza virus infection in humans was reported in China on March 31, 2013. Humans are immunologically naive to the H7N9 subtype, for which the seasonal influenza vaccine is not effective. Thus, the development of an H7N9 influenza virus vaccine is an urgent issue. To prepare for the emergence of an influenza pandemic, we have established a library comprising more than 1300 influenza virus strains with 144 different combinations of 16 HA and 9 NA subtypes. An H7N9 virus strain isolated from a 35-year-old woman, A/Anhui/1/2013 (H7N9), was found to be antigenically similar to H7N9 influenza viruses isolated from migratory ducks. In the present study, the potency of an inactivated whole virus particle vaccine prepared from an H7N9 low pathogenic avian influenza virus, A/duck/Mongolia/119/2008 (H7N9), selected from the library, was assessed by a challenge with A/Anhui/1/2013 (H7N9). The results indicate that the test vaccine was potent enough to induce sufficient immunity to reduce the impact of disease caused by the challenge with A/Anhui/1/2013 (H7N9) in mice. The present results indicate that an inactivated whole virus particle vaccine prepared from an influenza virus strain stored in the library could be useful as a vaccine strain in case of an influenza pandemic. (C) 2014 Published by Elsevier Ltd.
  • Yasushi Itoh, Reiko Yoshida, Shintaro Shichinohe, Megumi Higuchi, Hirohito Ishigaki, Misako Nakayama, Van Loi Pham, Hideaki Ishida, Mitsutaka Kitano, Masahiko Arikata, Naoko Kitagawa, Yachiyo Mitsuishi, Kazumasa Ogasawara, Hideaki Tsuchiya, Takahiro Hiono, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida, Mutsumi Ito, Le Quynh Mai, Yoshihiro Kawaoka, Hiroko Miyamoto, Mari Ishijima, Manabu Igarashi, Yasuhiko Suzuki, Ayato Takada
    PLOS PATHOGENS 10 (6) e1004192  1553-7366 2014/06 [Refereed][Not invited]
     
    Highly pathogenic avian influenza (HPAI) viruses of the H5N1 subtype often cause severe pneumonia and multiple organ failure in humans, with reported case fatality rates of more than 60%. To develop a clinical antibody therapy, we generated a human-mouse chimeric monoclonal antibody (MAb) ch61 that showed strong neutralizing activity against H5N1 HPAI viruses isolated from humans and evaluated its protective potential in mouse and nonhuman primate models of H5N1 HPAI virus infections. Passive immunization with MAb ch61 one day before or after challenge with a lethal dose of the virus completely protected mice, and partial protection was achieved when mice were treated 3 days after the challenge. In a cynomolgus macaque model, reduced viral loads and partial protection against lethal infection were observed in macaques treated with MAb ch61 intravenously one and three days after challenge. Protective effects were also noted in macaques under immunosuppression. Though mutant viruses escaping from neutralization by MAb ch61 were recovered from macaques treated with this MAb alone, combined treatment with MAb ch61 and peramivir reduced the emergence of escape mutants. Our results indicate that antibody therapy might be beneficial in reducing viral loads and delaying disease progression during H5N1 HPAI virus infection in clinical cases and combined treatment with other antiviral compounds should improve the protective effects of antibody therapy against H5N1 HPAI virus infection.
  • Takahiro Hiono, Masatoshi Okamatsu, Shoko Nishihara, Sayaka Takase-Yoden, Yoshihiro Sakoda, Hiroshi Kida
    VIROLOGY 456 131 - 138 0042-6822 2014/05 [Refereed][Not invited]
     
    Influenza viruses recognize sialoglycans as receptors. Although viruses isolated form chickens preferentially bind to sialic acid alpha 2,3 galactose (SA alpha 2,3Gal) glycans as do those of ducks, chickens were not experimentally infected with viruses isolated from ducks. A chicken influenza virus, A/chicken/Ibaraki/1/ 2005 (H5N2) (Ck/IBR) bound to fucose-branched SAa2,3Gal glycans, whereas the binding towards linear SAa2,3Gal glycans was weak. On the epithelial cells of the upper respiratory tracts of chickens, fucose-branched SA alpha 2,3Gal glycans were detected, but not linear SA alpha 2,3Gal glycans. The growth of Ck/IBR in MDCK-FUT cells, which were genetically prepared to express fucose-branched SA alpha 2,3Gal glycans, was significantly higher than that in the parental MDCK cells. The present results indicate that fucosebranched SA alpha 2,3Gal glycans existing on the epithelial cells lining the upper respiratory tracts of chickens are critical for recognition by Ck/IBR. (c) 2014 Elsevier Inc. All rights reserved.
  • Tomokazu Tamura, Naofumi Nagashima, Nicolas Ruggli, Artur Summerfield, Hiroshi Kida, Yoshihiro Sakoda
    VETERINARY RESEARCH 45 47  0928-4249 2014/04 [Refereed][Not invited]
     
    Classical swine fever (CSF) caused by CSF virus (CSFV) is a highly contagious disease of pigs. The viral protein N-pro of CSFV interferes with alpha-and beta-interferon (IFN-alpha/beta) induction by promoting the degradation of interferon regulatory factor 3 (IRF3). During the establishment of the live attenuated CSF vaccine strain GPE(-), N-pro acquired a mutation that abolished its capacity to bind and degrade IRF3, rendering it unable to prevent IFN-alpha/beta induction. In a previous study, we showed that the GPE(-) vaccine virus became pathogenic after forced serial passages in pigs, which was attributed to the amino acid substitutions T830A in the viral proteins E2 and V2475A and A2563V in NS4B. Interestingly, during the re-adaptation of the GPE(-) vaccine virus in pigs, the IRF3-degrading function of N-pro was not recovered. Therefore, we examined whether restoring the ability of N-pro to block IFN-alpha/beta induction of both the avirulent and moderately virulent GPE(-)-derived virus would enhance pathogenicity in pigs. Viruses carrying the N136D substitution in N-pro regained the ability to degrade IRF3 and suppress IFN-alpha/beta induction in vitro. In pigs, functional N-pro significantly reduced the local IFN-alpha mRNA expression in lymphoid organs while it increased quantities of IFN-alpha/beta in the circulation, and enhanced pathogenicity of the moderately virulent virus. In conclusion, the present study demonstrates that functional N-pro influences the innate immune response at local sites of virus replication in pigs and contributes to pathogenicity of CSFV in synergy with viral replication.
  • Junki Maruyama, Hiroko Miyamoto, Masahiro Kajihara, Hirohito Ogawa, Ken Maeda, Yoshihiro Sakoda, Reiko Yoshida, Ayato Takada
    JOURNAL OF VIROLOGY 88 (1) 99 - 109 0022-538X 2014/01 [Refereed][Not invited]
     
    Lloviu virus (LLOV), a novel filovirus detected in bats, is phylogenetically distinct from viruses in the genera Ebolavirus and Marburgvirus in the family Filoviridae. While filoviruses are known to cause severe hemorrhagic fever in humans and/or nonhuman primates, LLOV is biologically uncharacterized, since infectious LLOV has never been isolated. To examine the properties of LLOV, we characterized its envelope glycoprotein (GP), which likely plays a key role in viral tropism and pathogenicity. We first found that LLOV GP principally has the same primary structure as the other filovirus GPs. Similar to the other filoviruses, virus-like particles (VLPs) produced by transient expression of LLOV GP, matrix protein, and nucleoprotein in 293T cells had densely arrayed GP spikes on a filamentous particle. Mouse antiserum to LLOV VLP was barely cross-reactive to viruses of the other genera, indicating that LLOV is serologically distinct from the other known filoviruses. For functional study of LLOV GP, we utilized a vesicular stomatitis virus (VSV) pseudotype system and found that LLOV GP requires low endosomal pH and cathepsin L, and that human C-type lectins act as attachment factors for LLOV entry into cells. Interestingly, LLOV GP-pseudotyped VSV infected particular bat cell lines more efficiently than viruses bearing other filovirus GPs. These results suggest that LLOV GP mediates cellular entry in a manner similar to that of the other filoviruses while showing preferential tropism for some bat cells.
  • Haru Ogiwara, Fumihiko Yasui, Keisuke Munekata, Asako Takagi-Kamiya, Tsubasa Munakata, Namiko Nomura, Futoshi Shibasaki, Kazuhiko Kuwahara, Nobuo Sakaguchi, Yoshihiro Sakoda, Hiroshi Kida, Michinori Kohara
    AMERICAN JOURNAL OF PATHOLOGY 184 (1) 171 - 183 0002-9440 2014/01 [Refereed][Not invited]
     
    Patients infected with highly pathogenic avian influenza A H5N1 viruses (H5N1 HPAIV) show diffuse alveolar damage. However, the temporal progression of tissue damage and repair after viral infection remains poorly defined. Therefore, we assessed the sequential histopathological characteristics of mouse lung after intranasal infection with H5N1 HPAIV or H1N1 2009 pandemic influenza virus (H1N1 pdm). We determined the amount and localization of virus in the Lung through IHC staining and in situ hybridization. IHC used antibodies raised against the virus protein and antibodies specific for macrophages, type II pneumocytes, or proliferating cell nuclear antigen. In situ hybridization used RNA probes against both viral RNA and mRNA encoding the nucleoprotein and the hemagglutinin protein. H5N1 HPAIV infection and replication were observed in multiple lung cell types and might result in rapid progression of lung injury. Both type II pneumocytes and macrophages proliferated after H5N1 HPAIV infection. However, the abundant macrophages failed to block the viral attack, and proliferation of type II pneumocytes failed to restore the damaged alveoli. In contrast, mice infected with H1N1 pdm exhibited modest proliferation of type II pneumocytes and macrophages and slight alveolar damage. These results suggest that the virulence of H5N1 HPAIV results from the wide range of cell tropism of the virus, excessive virus replication, and rapid development of diffuse alveolar damage.
  • Tatsuya Nishi, Masatoshi Okamatsu, Kenji Sakurai, Huy Due Chu, Long Pham Thanh, Long van Nguyen, Nam van Hoang, Diep Nguyen Thi, Yoshihiro Sakoda, Hiroshi Kida
    JOURNAL OF VETERINARY MEDICAL SCIENCE 76 (1) 85 - 87 0916-7250 2014/01 [Refereed][Not invited]
     
    In August 2012, A/chicken/Vietnam/OIE-2215/2012 (H5N2) was isolated from a chicken in a live bird market (LBM) in Northern Vietnam. Intravenous pathogenicity test revealed that this virus is highly pathogenic in chickens. The PA, HA, NP and M, PB2 and NA, and PB1 and NS genes of the isolate were phylogenetically closely related to those of A/duck/Vietnam/OIE-2202/2012 (H5N1) of Glade 2.3.2.1, A/chicken/Vietnam/OIE-1611/2012 (H9N2) and A/chicken/Vietnam/OIE-2468/2012 (H9N2), respectively. All of these viruses were isolated from birds in LBMs in the same province. These results indicate that A/chicken/Vietnam/OIE-2215/2012 (H5N2) is a genetic reassortant and that surveillance of avian influenza in LBMs and stamping out policy are essential for the eradication of highly pathogenic avian influenza viruses from Asia.
  • Misako Nakayama, Shintaro Shichinohe, Yasushi Itoh, Hirohito Ishigaki, Mitsutaka Kitano, Masahiko Arikata, Van Loi Pham, Hideaki Ishida, Naoko Kitagawa, Masatoshi Okamatsu, Yoshihiro Sakoda, Takaya Ichikawa, Hideaki Tsuchiya, Shinichiro Nakamura, Quynh Mai Le, Mutsumi Ito, Yoshihiro Kawaoka, Hiroshi Kida, Kazumasa Ogasawara
    PLOS ONE 8 (12) e82740  1932-6203 2013/12 [Refereed][Not invited]
     
    H5N1 highly pathogenic avian influenza virus (HPAIV) infection has been reported in poultry and humans with expanding clade designations. Therefore, a vaccine that induces immunity against a broad spectrum of H5N1 viruses is preferable for pandemic preparedness. We established a second H5N1 vaccine candidate, A/duck/Hokkaido/Vac-3/2007 (Vac-3), in our virus library and examined the efficacy of inactivated whole particles of this strain against two clades of H5N1 HPAIV strains that caused severe morbidity in cynomolgus macaques. Virus propagation in vaccinated macaques infected with either of the H5N1 HPAIV strains was prevented compared with that in unvaccinated macaques. This vaccine also prevented propagation of a pandemic (H1N1) 2009 virus in macaques. In the vaccinated macaques, neutralization activity, which was mainly shown by anti-hemagglutinin antibody, against H5N1 HPAIVs in plasma was detected, but that against H1N1 virus was not detected. However, neuraminidase inhibition activity in plasma and T-lymphocyte responses in lymph nodes against H1N1 virus were detected. Therefore, cross-clade and heterosubtypic protective immunity in macaques consisted of humoral and cellular immunity induced by vaccination with Vac-3.
  • Naoki Yamamoto, Yoshihiro Sakoda, Masatoshi Okamatsu, Hiroshi Kida
    VIRUS RESEARCH 178 (2) 404 - 410 0168-1702 2013/12 [Refereed][Not invited]
     
    Influenza virus A/Hong Kong/483/97 (H5N1) (HK483-K) has the PB2 with lysine at position 627 (PB2-627K) and is highly pathogenic in chickens and mice. On the other hand, the pathogenicity of mutant virus (HK483-E), which was generated by substituting lysine with glutamic acid at the position of the PB2, is lower than that of HK483-K in mice, but is highly pathogenic in chickens. The PB2 is one of the components of heterotrimeric polymerase complex, which plays roles in the transcription and replication of virus genes. Cell-free polymerase assay revealed that intrinsic transcription activity of the polymerase complex with PB2-627K is higher than that of glutamic acid (PB2-627E). In chicken cells, transcription efficiency of the polymerase complex with PB2-627E was not lower than those with PB2-627K, indicating that transcription of virus genes is modulated by some host factors in chicken cells, resulting in high growth. Polymerase complex with PB2-627K efficiently transcribes and replicates virus polymerase genes in mouse cells, leading to high growth of HK483-K compared with that of HK483-E. The results of our experiments clearly suggest that efficient transcription and replication of virus genes by polymerase complex result in the higher pathogenicity in mice. (C) 2013 Elsevier B.V. All rights reserved.
  • Junki Maruyama, Masatoshi Okamatsu, Kosuke Soda, Yoshihiro Sakoda, Hiroshi Kida
    ARCHIVES OF VIROLOGY 158 (12) 2473 - 2478 0304-8608 2013/12 [Refereed][Not invited]
     
    Highly pathogenic avian influenza viruses have poly-basic amino acid sequences at the cleavage site in their hemagglutinin (HA). Although this poly-basic region is a prerequisite factor for pathogenicity in chickens, not much is known about additional factors responsible for the acquisition of pathogenicity of the duck influenza virus in chickens. Here, we introduced multiple basic amino acid residues into the HA cleavage site of the A/duck/Hokkaido/Vac-2/2004 (H7N7) strain of avian influenza virus, which has low pathogenicity in chickens; the resultant Vac2sub-P0 strain was not intravenously pathogenic in chickens. In contrast, the Vac2sub-P3 strain, which was recovered from three consecutive passages of Vac2sub-P0 in chicks, was intravenously pathogenic in chickens. Six amino acid substitutions were identified by comparison of the Vac2sub-P3 and Vac2sub-P0 genomic sequences: Lys123Glu in PB2, Asn16Asp in PB1, Glu227Gly and Ile388Thr in HA, Gly228Arg in M1, and Leu46Pro in M2. The results of intravenous inoculations of chickens with recombinant virus indicated that all six amino acid substitutions were required to varying degrees for Vac2sub-P3 pathogenicity, with Glu227Gly and Ile388Thr in HA being particularly essential. These results reveal the roles of additional viral factors in the acquisition of pathogenicity in addition to the previously characterized role of the poly-basic amino acid sequences at the HA cleavage site.
  • Akira Sakurai, Katsuyoshi Takayama, Namiko Nomura, Tsubasa Munakata, Naoki Yamamoto, Tsuruki Tamura, Jitsuho Yamada, Masako Hashimoto, Kazuhiko Kuwahara, Yoshihiro Sakoda, Yoshihiko Suda, Yukuharu Kobayashi, Nobuo Sakaguchi, Hiroshi Kida, Michinori Kohara, Futoshi Shibasaki
    PLoS ONE 8 (11) e76753  1932-6203 2013/11/06 [Refereed][Not invited]
     
    Immunochromatography (IC) is an antigen-detection assay that plays an important role in the rapid diagnosis of influenza virus because the protocol is short time and easy to use. Despite the usability of IC, the sensitivity is approximately 103 pfu per reaction. In addition, antigen-antibody interaction-based method cannot be used for the detection of influenza viruses with major antigenic change. In this study, we established the use of fluorescent immunochromatography (FLIC) to detect a broad spectrum of H5 subtype influenza A viruses. This method has improved sensitivity 10-100 fold higher than traditional IC because of the use of fluorescent conjugated beads. Our Type-E FLIC kit detected all of the H5 subtype influenza viruses that were examined, as well as recombinant hemagglutinin (HA) proteins (rHAs) belonging to the Eurasian H5 subtype viruses and the Type-N diagnosed North American H5 subtype influenza A viruses. Thus, this kit has the improved potential to detect H5 subtype influenza viruses of different clades with both Type-E and Type-N FLIC kits. Compared with PCR-based diagnosis, FLIC has a strong advantage in usability, because the sample preparation required for FLIC is only mix-and-drop without any additional steps such as RNA extraction. Our results can provide new strategies against the spread and transmission of HPAI H5N1 viruses in birds and mammals including humans. Copyright: © 2013 Sakurai et al.
  • Masatoshi Okamatsu, Tatsuya Nishi, Naoki Nomura, Naoki Yamamoto, Yoshihiro Sakoda, Kenji Sakurai, Huy Duc Chu, Long Pham Thanh, Long Van Nguyen, Nam Van Hoang, Tien Ngoc Tien, Reiko Yoshida, Ayato Takada, Hiroshi Kida
    VIRUS GENES 47 (2) 317 - 329 0920-8569 2013/10 [Refereed][Not invited]
     
    To estimate the prevalence of avian influenza virus infection in Vietnam, surveillance was conducted in domestic and wild birds from households, live-bird markets, slaughtering sites, and bird sanctuaries in Vietnam between October 2010 and October 2012. Of the 4,550 samples collected, 226 influenza A virus isolates were obtained from domestic ducks, muscovy ducks, and chickens. Of these, 25 and 22 H5N1 highly pathogenic avian influenza viruses (HPAIVs) were isolated from apparently healthy domestic ducks in live-bird markets and slaughtering sites in northern and southern Vietnam, respectively. The HA genes of H5 viruses isolated from birds in northern Vietnam phylogenetically belonged to the genetic clade 2.3.2.1 and those in southern Vietnam belonged to the genetic clade 1.1. In addition, 39 H3, 12 H4, 1 H5, 93 H6, 2 H7, 18 H9, 3 H10, and 11 H11 viruses were isolated. Phylogenetic and antigenic analyses of the H6 and H9 viruses revealed that they were closely related to the isolates obtained from domestic poultry in China. Phylogenetic analyses of internal gene segments of these isolates revealed that these viruses were circulating in both domestic and wild birds in Asia and reassortment events had occurred frequently. Therefore, it will be important to continue the surveillance and strict controls over the movement and trade of poultry and poultry products in order to eradicate H5N1 HPAIV from Asia.
  • Van Loi Pham, Misako Nakayama, Yasushi Itoh, Hirohito Ishigaki, Mitsutaka Kitano, Masahiko Arikata, Hideaki Ishida, Naoko Kitagawa, Shintaro Shichinohe, Masatoshi Okamatsu, Yoshihiro Sakoda, Hideaki Tsuchiya, Shinichiro Nakamura, Hiroshi Kida, Kazumasa Ogasawara
    PLOS ONE 8 (9) e75910  1932-6203 2013/09 [Refereed][Not invited]
     
    Pandemic (H1N1) 2009 influenza virus spread throughout the world since most people did not have immunity against the virus. In the post pandemic phase when many humans might possess immunity against the pandemic virus, one of the concerns is infection in immunocompromised people. Therefore, we used an immunosuppressed macaque model to examine pathogenicity of the pandemic (H1N1) 2009 virus under an immunocompromised condition. The virus in nasal samples of immunosuppressed macaques infected with the pandemic (H1N1) 2009 virus was detected longer after infection than was the virus in nasal samples of immunocompetent macaques. As expected, not only virus amounts but also virus propagation sites in the immunosuppressed macaques were larger than those in lungs of the immunocompetent macaques when they were infected with the pandemic virus. Immunosuppressed macaques possessed low levels of immune cells producing cytokines and chemokines, but levels of inflammatory cytokines/chemokine interleukin (IL)-6, IL-18, and monocyte chemotactic protein (MCP)-1 in lungs of the immunosuppressed macaques were higher than those in lungs of the immunocompetent macaques, though the differences were not statistically significant. Therefore, under an immunosuppressive condition, the pandemic influenza (H1N1) 2009 virus might cause more severe morbidity with high cytokine/chemokine production by the host innate immune system than that seen in macaques under the immunocompetent condition.
  • Shintaro Shichinohe, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida
    VIROLOGY 444 (1-2) 404 - 408 0042-6822 2013/09 [Refereed][Not invited]
     
    Avian influenza viruses possess hemagglutinin (HA) which preferentially bind to the sialic acid alpha 2,3-galactose sialyloligosaccharides (SA alpha 2,3Gal) receptor. In contrast, human influenza viruses bind to sialic acid alpha 2,6-galactose sialyloligosaccharides (SA alpha 2,6Gal). The A/Hong Kong/68 (H3N2) virus preferentially binds to SA alpha 2,6Gal, although its HA gene was derived from an avian influenza virus strain. To elucidate the mechanisms behind acquisition of binding specificity for the human-type receptor, the avian influenza virus, A/duck/Hokkaido/5/77 (H3N2), which carries the HA with SA alpha 2,3Gal receptor specificity, was consecutively passaged in pigs. Viruses that preferentially bind to the SA alpha 2,6Gal receptor were predominantly recovered from the nasal swabs of pigs after three passages. The present results indicate that avian influenza Viruses can acquire the potential to infect humans after multiple infections in a pig population. Intensive surveillance of swine influenza is, thus, important for the preparedness for the future pandemics. (C) 2013 Elsevier Inc. All rights reserved.
  • Tokiko Watanabe, Maki Kiso, Satoshi Fukuyama, Noriko Nakajima, Masaki Imai, Shinya Yamada, Shin Murakami, Seiya Yamayoshi, Kiyoko Iwatsuki-Horimoto, Yoshihiro Sakoda, Emi Takashita, Ryan McBride, Takeshi Noda, Masato Hatta, Hirotaka Imai, Dongming Zhao, Noriko Kishida, Masayuki Shirakura, Robert P. de Vries, Shintaro Shichinohe, Masatoshi Okamatsu, Tomokazu Tamura, Yuriko Tomita, Naomi Fujimoto, Kazue Goto, Hiroaki Katsura, Eiryo Kawakami, Izumi Ishikawa, Shinji Watanabe, Mutsumi Ito, Yuko Sakai-Tagawa, Yukihiko Sugita, Ryuta Uraki, Reina Yamaji, Amie J. Eisfeld, Gongxun Zhong, Shufang Fan, Jihui Ping, Eileen A. Maher, Anthony Hanson, Yuko Uchida, Takehiko Saito, Makoto Ozawa, Gabriele Neumann, Hiroshi Kida, Takato Odagiri, James C. Paulson, Hideki Hasegawa, Masato Tashiro, Yoshihiro Kawaoka
    NATURE 501 (7468) 551 - + 0028-0836 2013/09 [Refereed][Not invited]
     
    Avian influenza A viruses rarely infect humans; however, when human infection and subsequent human-to-human transmission occurs, worldwide outbreaks (pandemics) can result. The recent sporadic infections of humans in China with a previously unrecognized avian influenza A virus of the H7N9 subtype (A(H7N9)) have caused concern owing to the appreciable case fatality rate associated with these infections (more than 25%), potential instances of human-to-human transmission(1), and the lack of pre-existing immunity among humans to viruses of this subtype. Here we characterize two early human A(H7N9) isolates, A/Anhui/1/2013 (H7N9) and A/Shanghai/1/2013 (H7N9); hereafter referred to as Anhui/1 and Shanghai/1, respectively. In mice, Anhui/1 and Shanghai/1 were more pathogenic than a control avian H7N9 virus (A/duck/Gunma/466/2011 (H7N9); Dk/GM466) and a representative pandemic 2009 H1N1 virus (A/California/4/2009 (H1N1pdm09); CA04). Anhui/1, Shanghai/1 and Dk/GM466 replicated well in the nasal turbinates of ferrets. In nonhuman primates, Anhui/1 and Dk/GM466 replicated efficiently in the upper and lower respiratory tracts, whereas the replicative ability of conventional human influenza viruses is typically restricted to the upper respiratory tract of infected primates. By contrast, Anhui/1 did not replicate well in miniature pigs after intranasal inoculation. Critically, Anhui/1 transmitted through respiratory droplets in one of three pairs of ferrets. Glycan arrays showed that Anhui/1, Shanghai/1 and A/Hangzhou/1/2013 (H7N9) (a third human A(H7N9) virus tested in this assay) bind to human virus-type receptors, a property that may be critical for virus transmissibility in ferrets. Anhui/1 was found to be less sensitive in mice to neuraminidase inhibitors than a pandemic H1N1 2009 virus, although both viruses were equally susceptible to an experimental antiviral polymerase inhibitor. The robust replicative ability in mice, ferrets and nonhuman primates and the limited transmissibility in ferrets of Anhui/1 suggest that A(H7N9) viruses have pandemic potential.
  • Saya Kuribayashi, Yoshihiro Sakoda, Takeshi Kawasaki, Tomohisa Tanaka, Naoki Yamamoto, Masatoshi Okamatsu, Norikazu Isoda, Yoshimi Tsuda, Yuji Sunden, Takashi Umemura, Noriko Nakajima, Hideki Hasegawa, Hiroshi Kida
    PLOS ONE 8 (7) e68375  1932-6203 2013/07 [Refereed][Not invited]
     
    Highly pathogenic avian influenza viruses (HPAIVs) cause lethal infection in chickens. Severe cases of HPAIV infections have been also reported in mammals, including humans. In both mammals and birds, the relationship between host cytokine response to the infection with HPAIVs and lethal outcome has not been well understood. In the present study, the highly pathogenic avian influenza viruses A/turkey/Italy/4580/1999 (H7N1) (Ty/Italy) and A/chicken/Netherlands/2586/2003 (H7N7) (Ck/NL) and the low pathogenic avian influenza virus (LPAIV) A/chicken/Ibaraki/1/2005 (H5N2) (Ck/Ibaraki) were intranasally inoculated into chickens. Ty/Italy replicated more extensively than Ck/NL in systemic tissues of the chickens, especially in the brain, and induced excessive mRNA expression of inflammatory and antiviral cytokines (IFN-gamma, IL-1 beta, IL-6, and IFN-alpha) in proportion to its proliferation. Using in situ hybridization, IL-6 mRNA was detected mainly in microglial nodules in the brain of the chickens infected with Ty/Italy. Capillary leakage assessed by Evans blue staining was observed in multiple organs, especially in the brains of the chickens infected with Ty/Italy, and was not observed in those infected with Ck/NL. In contrast, LPAIV caused only local infection in the chickens, with neither apparent cytokine expression nor capillary leakage in any tissue of the chickens. The present results indicate that an excessive cytokine response is induced by rapid and extensive proliferation of HPAIV and causes fatal multiple organ failure in chickens.
  • Ahmad M. Haredy, Nobuyuki Takenaka, Hiroshi Yamada, Yoshihiro Sakoda, Masatoshi Okamatsu, Naoki Yamamoto, Takeshi Omasa, Hisao Ohtake, Yasuko Mori, Hiroshi Kida, Koichi Yamanishi, Shigefumi Okamoto
    Clinical and Vaccine Immunology 20 (7) 998 - 1007 1556-6811 2013/07 [Refereed][Not invited]
     
    It is currently impossible to predict the next pandemic influenza virus strain. We have thus established a library of influenza viruses of all hemagglutinin and neuraminidase subtypes and their genes. In this article, we examine the applicability of a rapid production model for the preparation of vaccines against emerging pandemic influenza viruses. This procedure utilizes the influenza virus library, cell culture-based vaccine production, and intranasal administration to induce a cross-protective immune response. First, an influenza virus reassortant from the library, A/duck/Hokkaido/Vac-3/2007 (H5N1), was passaged 22 times (P22) in Madin-Darby canine kidney (MDCK) cells. The P22 virus had a titer of > 2 × 108PFU/ml, which was 40 times that of the original strain, with 4 point mutations, which altered amino acids in the deduced protein sequences encoded by the PB2 and PA genes. We then produced a formalin-inactivated whole-virion vaccine from the MDCK cell-cultured A/duck/Hokkaido/Vac-3/2007 (H5N1) P22 virus. Intranasal immunization of mice with this vaccine protected them against challenges with lethal influenza viruses of homologous and heterologous subtypes. We further demonstrated that intranasal immunization with the vaccine induced cross-reactive neutralizing antibody responses against the homotypic H5N1 influenza virus and its antigenic variants and cross-reactive cell-mediated immune responses to the homologous virus, its variants within a subtype, and even an influenza virus of a different subtype. These results indicate that a rapid model for emergency vaccine production may be effective for producing the next generation of pandemic influenza virus vaccines. Copyright © 2013, American Society for Microbiology. All Rights Reserved.
  • Naoki Yamamoto, Kosuke Soda, Yoshihiro Sakoda, Masatoshi Okamatsu, Hiroshi Kida
    VIRUS RESEARCH 173 (2) 294 - 298 0168-1702 2013/05 [Refereed][Not invited]
     
    Influenza virus rgVac1 sub-P0 (H5N1) (rgVac1-P0), in which a pair of dibasic,amino acid residues was introduced at the cleavage site of the HA of a reassortant of H5N2 and H7N1 viruses of duck origin, was low pathogenic in chickens. Vac1 sub-P3 (H5N1) (Vac1-P3) was selected as a highly pathogenic avian influenza virus by 3 consecutive passages in chickens from low pathogenic strain rgVac1-P0. Comparison of amino acid sequences of the virus proteins and experimental infection of chickens with a series of recombinant viruses demonstrated that in addition to the HA, each of the PA, NP, M1, and M2 of Vac1-P3 are responsible for the acquisition of pathogenicity in chickens. These 4 proteins of Vac1-P3 synergistically contributed to efficient virus replication in chickens. (C) 2013 Elsevier B.V. All rights reserved.
  • Shintaro Shichinohe, Masatoshi Okamatsu, Naoki Yamamoto, Yu Noda, Yuka Nomoto, Takashi Honda, Noriyasu Takikawa, Yoshihiro Sakoda, Hiroshi Kida
    VETERINARY MICROBIOLOGY 164 (1-2) 39 - 45 0378-1135 2013/05 [Refereed][Not invited]
     
    Antigenic variants of H5N1 highly pathogenic avian influenza virus (HPAIV) have selected and are prevailing in poultry populations in Asia. In the present study, the potency of inactivated influenza vaccine prepared from a non-pathogenic H5N1 avian influenza virus, A/duck/Hokkaido/Vac-3/2007 (H5N1), was assessed by challenging with H5N1 HPAIV variants, A/muscovy duck/Vietnam/OIE-559/2011 (H5N1), A/whooper swan/Hokkaido/4/2011 (H5N1), and A/peregrine falcon/Hong Kong/810/2009 (H5N1) belonging to clades 1, 23.2.1, and 2.3.4, respectively. All chickens immunized with the Vac-3 vaccine survived without showing any clinical signs after intranasal challenge either with A/whooper swan/Hokkaido/4/2011 (H5N1) or A/muscovy duck/Vietnam/OIE-559/2011 (H5N1). After challenge with A/peregrine falcon/Hong Kong/810/2009 (H5N1), 10 out of 12 vaccinated chickens survived and the other 2 died on 4 or 7 post-challenge days. The Vac-3 vaccine of 2.4-fold antigen concentration conferred complete protective immunity in chickens against challenge with A/peregrine falcon/Hong Kong/810/2009 (H5N1). (C) 2013 Elsevier B.V. All rights reserved.
  • Yurie Motohashi, Manabu Igarashi, Masatoshi Okamatsu, Takeshi Noshi, Yoshihiro Sakoda, Naoki Yamamoto, Kimihito Ito, Ryu Yoshida, Hiroshi Kida
    VIROLOGY JOURNAL 10 118  1743-422X 2013/04 [Refereed][Not invited]
     
    Background: The hemagglutinin (HA) of influenza viruses is a possible target for antiviral drugs because of its key roles in the initiation of infection. Although it was found that a natural compound, Stachyflin, inhibited the growth of H1 and H2 but not H3 influenza viruses in MDCK cells, inhibitory activity of the compound has not been assessed against H4-H16 influenza viruses and the precise mechanism of inhibition has not been clarified. Methods: Inhibitory activity of Stachyflin against H4-H16 influenza viruses, as well as H1-H3 viruses was examined in MDCK cells. To identify factors responsible for the susceptibility of the viruses to this compound, Stachyflin-resistant viruses were selected in MDCK cells and used for computer docking simulation. Results: It was found that in addition to antiviral activity of Stachyflin against influenza viruses of H1 and H2 subtypes, it inhibited replication of viruses of H5 and H6 subtypes, as well as A(H1N1)pdm09 virus in MDCK cells. Stachyflin also inhibited the virus growth in the lungs of mice infected with A/WSN/1933 (H1N1) and A/chicken/Ibaraki/1/2005 (H5N2). Substitution of amino acid residues was found on the HA2 subunit of Stachyflin-resistant viruses. Docking simulation indicated that D37, K51, T107, and K121 are responsible for construction of the cavity for the binding of the compound. In addition, 3-dimensional structure of the cavity of the HA of Stachyflin-susceptible virus strains was different from that of insusceptible virus strains. Conclusion: Antiviral activity of Stachyflin was found against A(H1N1) pdm09, H5, and H6 viruses, and identified a potential binding pocket for Stachyflin on the HA. The present results should provide us with useful information for the development of HA inhibitors with more effective and broader spectrum.
  • Feng F, Sakoda Y, Ohyanagi T, Nagahori N, Shibuya H, Okamastu M, Miura N, Kida H, Nishimura SI
    Antiviral therapy 1359-6535 2013/02 [Refereed][Not invited]
  • Masahiro Kajihara, Yoshihiro Sakoda, Kosuke Soda, Kenji Minari, Masatoshi Okamatsu, Ayato Takada, Hiroshi Kida
    VIROLOGY JOURNAL 10 45  1743-422X 2013/02 [Refereed][Not invited]
     
    Background: Wild ducks are the natural hosts of influenza A viruses. Duck influenza, therefore, has been believed inapparent infection with influenza A viruses, including highly pathogenic avian influenza viruses (HPAIVs) in chickens. In fact, ducks experimentally infected with an HPAIV strain, A/Hong Kong/483/1997 (H5N1) (HK483), did not show any clinical signs. Another HPAIV strain, A/whooper swan/Mongolia/3/2005 (H5N1) (MON3) isolated from a dead swan, however, caused neurological dysfunction and death in ducks. Method: To understand the mechanism whereby MON3 shows high pathogenicity in ducks, HK483, MON3, and twenty-four reassortants generated between these two H5N1 viruses were compared for their pathogenicity in domestic ducks. Results: None of the ducks infected with MON3-based single-gene reassortants bearing the PB2, NP, or NS gene segment of HK483 died, and HK483-based single-gene reassortants bearing PB2, NP, or NS genes of MON3 were not pathogenic in ducks, suggesting that multiple gene segments contribute to the pathogenicity of MON3 in ducks. All the ducks infected with the reassortant bearing PB2, PA, HA, NP, and NS gene segments of MON3 died within five days post-inoculation, as did those infected with MON3. Each of the viruses was assessed for replication in ducks three days post-inoculation. MON3 and multi-gene reassortants pathogenic in ducks were recovered from all of the tissues examined and replicated with high titers in the brains and lungs. Conclusion: The present results indicate that multigenic factors are responsible for efficient replication of MON3 in ducks. In particular, virus growth in the brain might correlate with neurological dysfunction and the disease severity.
  • Masatoshi Okamatsu, Yoshihiro Sakoda, Takahiro Hiono, Naoki Yamamoto, Hiroshi Kida
    VIROLOGY JOURNAL 10 47  1743-422X 2013/02 [Refereed][Not invited]
     
    Background: The pandemic 2009 (H1N1) influenza virus has spread throughout the world and is now causing seasonal influenza. To prepare for the emergence of pandemic influenza, we have established a library of virus strains isolated from birds, pigs, and humans in global surveillance studies. Methods: Inactivated whole virus particle (WV) and ether-split (ES) vaccines were prepared from an influenza virus strain, A/swine/Hokkaido/2/1981 (H1N1), from the library and from A/Narita/1/2009 (H1N1) pandemic strain. Each of the vaccines was injected subcutaneously into mice and their potencies were evaluated by challenge with A/Narita/1/2009 (H1N1) virus strain in mice. Results: A/swine/Hokkaido/2/81 (H1N1), which was isolated from the lung of a diseased piglet, was selected on the basis of their antigenicity and growth capacity in embryonated chicken eggs. Two injections of the WV vaccine induced an immune response in mice, decreasing the impact of disease caused by the challenge with A/Narita/1/2009 (H1N1), as did the vaccine prepared from the homologous strain. Conclusion: The WV vaccine prepared from an influenza virus in the library is useful as an emergency vaccine in the early phase of pandemic influenza.
  • Masatoshi Okamatsu, Fei Feng, Tatsuya Ohyanagi, Noriko Nagahori, Kazuhiko Someya, Yoshihiro Sakoda, Nobuaki Miura, Shin-Ichiro Nishimura, Hiroshi Kida
    JOURNAL OF VIROLOGICAL METHODS 187 (2) 390 - 394 0166-0934 2013/02 [Refereed][Not invited]
     
    Attachment of influenza virus to susceptible cells is mediated by viral protein hemagglutinin (HA), which recognizes cell surface glycoconjugates that terminate in alpha-sialosides. To develop anti-influenza drugs based on inhibition of HA-mediated infection, novel fluorescent nanoparticles displaying multiple biantennary N-glycan chains with alpha-sialosides (A2-PC-QDs) that have high affinity for the HA were designed and constructed. The A2-PC-QDs enabled an easy and efficient fluorescence polarization (FP) assay for detection of interaction with the HA and competitive inhibition even by small molecule compounds against A2-PC-QDs-HA binding. The quantum dot (QD)-based FP assay established in the present study is a useful tool for high-throughput screening and to accelerate the development of novel and more effective blockers of the viral attachment of influenza virus. (C) 2012 Elsevier B.V. All rights reserved.
  • Fei Feng, Yoshihiro Sakoda, Tatsuya Ohyanagi, Noriko Nagahori, Hitomi Shibuya, Masatoshi Okamastu, Nobuaki Miura, Hiroshi Kida, Shin-Ichiro Nishimura
    Antiviral Chemistry and Chemotherapy 23 (2) 59 - 65 0956-3202 2013 [Refereed][Not invited]
     
    Background: The purpose of this study was to develop a new class of influenza A virus haemagglutinin (HA) blockers by tethering thiosialoside molecules to metal nanoparticles and producing glycoclusters that enhance the affinity of HA binding by N-acetylneuraminic acid. Methods: Oxygen of the glycoside bond of sialoside was replaced with sulfur to prevent hydrolytic digestion of the N-acetylneuraminic acid residue by viral neuraminidase. Two novel thiosialosides, α-2-S-[p-(N-levulinyl) aminophenyl]-5-N-acetylneuraminic acid (Neu5Ac-S-Lev) and α-2-S-[m-(N-levulinyl)aminobenzyl]-5-Nacetylneuraminic acid (Neu5Ac-S-CH 2-Lev), were tethered onto the surface of metal nanoparticles via an aminooxy functionalized thiol linker in a glycoblotting reaction. Gold (Au) and silver (Ag) nanoparticles were coated simultaneously with 11-mercaptoundecyl phosphorylcholine to reduce non-specific adsorption of proteins. Phosphorylcholine self-assembled monolayercoated metals displaying clustered Neu5Ac (Neu5Ac-PCSAM-Au and Neu5Ac-PCSAM-Ag) were subjected to haemagglutination inhibition (HI) assays using the influenza A virus strain A/PR/8/1934 (H1N1). Results: Glyconanoparticles with thiosialosides had potent HI activities. In particular, Neu5Ac-PCSAM-Au with a diameter of 20 nm corresponding to 9.8 μM monosaccharide Neu5Ac was the most potent HA inhibitor. The versatility of this strategy was demonstrated by similar submicromolar HI activities of Neu5Ac-PCSAM--Ag with diameters of 50 nm and 150 nm. Conclusions: Glycosylated metal nanoparticles were designed and synthesized as potent influenza A virus HA blockers. This study may contribute to the acceleration of the discovery of a new class of nanoparticle antiinfluenza drugs. © 2013 International Medical Press.
  • Norikazu Isoda, Yoshimi Tsuda, Shingo Asakura, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida
    ARCHIVES OF VIROLOGY 157 (12) 2257 - 2264 0304-8608 2012/12 [Refereed][Not invited]
     
    Avian influenza viruses A/duck/Mongolia/47/2001 (H7N1) (47/01) and A/duck/Mongolia/867/2002 (H7N1) (867/02) were defined as low-pathogenic avian influenza viruses (LPAIVs) using an intravenous pathogenicity test in chickens. On the other hand, the intracerebral pathogenicity indices of 47/01 and 867/02 were 1.30 and 0.00, respectively. A series of reassortant viruses were generated between 47/01 and 867/02, and their intracerebral pathogenicity was compared in one-day-old chicks to identify the protein(s) responsible for the intracerebral pathogenicity of 47/01. The results indicate that the amino acids at positions 50 and 98 of the nucleoprotein are related to the pathogenicity of 47/01 in chicks by intracerebral inoculation. A significant association was found between mortality of the chicks inoculated intracerebrally with 47/01 and virus replication in the lungs and/or brain. These results indicate that the NP of avian influenza viruses may be responsible for intracerebral pathogenicity in the host.
  • Tomokazu Tamura, Yoshihiro Sakoda, Fumi Yoshino, Takushi Nomura, Naoki Yamamoto, Yuka Sato, Masatoshi Okamatsu, Nicolas Ruggli, Hiroshi Kida
    JOURNAL OF VIROLOGY 86 (16) 8602 - 8613 0022-538X 2012/08 [Refereed][Not invited]
     
    Classical swine fever virus (CSFV) is the causative agent of classical swine fever (CSF), a highly contagious disease of pigs. There are numerous CSFV strains that differ in virulence, resulting in clinical disease with different degrees of severity. Low-virulent and moderately virulent isolates cause a mild and often chronic disease, while highly virulent isolates cause an acute and mostly lethal hemorrhagic fever. The live attenuated vaccine strain GPE(-) was produced by multiple passages of the virulent ALD strain in cells of swine, bovine, and guinea pig origin. With the aim of identifying the determinants responsible for the attenuation, the GPE- vaccine virus was readapted to pigs by serial passages of infected tonsil homogenates until prolonged viremia and typical signs of CSF were observed. The GPE(-)/P-11 virus isolated from the tonsils after the 11th passage in vivo had acquired 3 amino acid substitutions in E2 (T830A) and NS4B (V2475A and A2563V) compared with the virus before passages. Experimental infection of pigs with the mutants reconstructed by reverse genetics confirmed that these amino acid substitutions were responsible for the acquisition of pathogenicity. Studies in vitro indicated that the substitution in E2 influenced virus spreading and that the changes in NS4B enhanced the viral RNA replication. In conclusion, the present study identified residues in E2 and NS4B of CSFV that can act synergistically to influence virus replication efficiency in vitro and pathogenicity in pigs.
  • Yoshihiro Sakoda, Hiroaki Wakamoto, Tehpin Tamura, Takushi Nomura, Michiko Naito, Hiroshi Aoki, Hiroshi Morita, Hiroshi Kida, Akio Fukusho
    JAPANESE JOURNAL OF VETERINARY RESEARCH 60 (2-3) 85 - 94 0047-1917 2012/08 [Refereed][Not invited]
     
    An indirect enzyme-linked immunosorbent assay (ELISA) was developed for a screening test to detect antibodies against classical swine fever virus (CSFV). Viral glycoproteins, which were purified from swine kidney cells infected with CSFV ALD/A76 strain by the immunoaffinity purification using monoclonal antibody against E2 protein, were adsorbed on a microtiter plate as the antigen for the antibody detection. Each antibody titer of serum sample was expressed as a sample per positive value calculated with optical absorbance of each sample and that of a positive control. The advantage of this ELISA is its higher sensitivity: most sera containing more than 4 neutralization titers were determined to be positive. This ELISA is unable to discriminate between antibodies against CSFV and those against other ruminant pestiviruses, therefore positive sera in this ELISA should be evaluated by a cross-neutralization test using CSFV, bovine viral diarrhea virus, and border disease virus. Taken together, the indirect ELISA developed in this study is useful screening tool to detect antibodies against CSFV for the large-scale monitoring of classical swine fever.
  • Yoshihiro Sakoda, Michiko Naito, Mutsumi Ito, Yuki Ito, Norikazu Isoda, Tomohisa Tanaka, Takashi Umemura, Hiroshi Kida
    JOURNAL OF VETERINARY MEDICAL SCIENCE 74 (7) 955 - 958 0916-7250 2012/07 [Refereed][Not invited]
     
    Leptospira interrogans serovar Manilae strain UP-MMC was inoculated into miniature pigs to assess its pathogenicity. Leptospires were recovered from the whole blood, kidneys, and livers in the acute phase without showing any clinical signs. Under immunosuppressive conditions by dexamethasone, leptospires were recovered from the kidneys and their genes were detected from the urine in the chronic phase. These results indicate that leptospires persisted in the kidneys until the chronic phase, and excretion of leptospires in the urine was enhanced under immunosuppressive conditions, resulting in horizontal transmission among pigs on farms.
  • Yoshihiro Sakoda, Masatoshi Okamatsu, Norikazu Isoda, Naoki Yamamoto, Koichi Ozaki, Yasuto Umeda, Shigeyuki Aoyama, Hiroshi Kida
    MICROBIOLOGY AND IMMUNOLOGY 56 (7) 490 - 495 0385-5600 2012/07 [Refereed][Not invited]
     
    Affinity chromatography using sulfated, spherical cellulose beads (Cellufine Sulfate) was assessed for purification of influenza A and influenza B viruses. Recovery rates of viruses eluted from the beads were high for all tested virus strains. This method was also useful for removing chicken egg-derived impurities from allantoic fluids containing influenza viruses; the hemagglutination activity per amount of protein in the eluted sample was significantly higher than that in the applied sample. These results suggest that use of Cellufine Sulfate is a practical method for primary purification of influenza viruses in the process of influenza vaccine production.
  • Masahiko Arikata, Yasushi Itoh, Masatoshi Okamatsu, Toshinaga Maeda, Takashi Shiina, Keiko Tanaka, Shingo Suzuki, Misako Nakayama, Yoshihiro Sakoda, Hirohito Ishigaki, Ayato Takada, Hideaki Ishida, Kosuke Soda, Van Loi Pham, Hideaki Tsuchiya, Shinichiro Nakamura, Ryuzo Torii, Takeshi Shimizu, Hidetoshi Inoko, Iwao Ohkubo, Hiroshi Kida, Kazumasa Ogasawara
    PLOS ONE 7 (5) e37220  1932-6203 2012/05 [Refereed][Not invited]
     
    We made an H1N1 vaccine candidate from a virus library consisting of 144 (= 16 HAx9 NA) non-pathogenic influenza A viruses and examined its protective effects against a pandemic (2009) H1N1 strain using immunologically naive cynomolgus macaques to exclude preexisting immunity and to employ a preclinical study since preexisting immunity in humans previously vaccinated or infected with influenza virus might make comparison of vaccine efficacy difficult. Furthermore, macaques carrying a major histocompatibility complex class I molecule, Mafa-A1*052:02, were used to analyze peptide-specific CD8(+) T cell responses. Sera of macaques immunized with an inactivated whole particle formulation without addition of an adjuvant showed higher neutralization titers against the vaccine strain A/Hokkaido/2/1981 (H1N1) than did sera of macaques immunized with a split formulation. Neutralization activities against the pandemic strain A/Narita/1/2009 (H1N1) in sera of macaques immunized twice with the split vaccine reached levels similar to those in sera of macaques immunized once with the whole particle vaccine. After inoculation with the pandemic virus, the virus was detected in nasal samples of unvaccinated macaques for 6 days after infection and for 2.67 days and 5.33 days on average in macaques vaccinated with the whole particle vaccine and the split vaccine, respectively. After the challenge infection, recall neutralizing antibody responses against the pandemic virus and CD8(+) T cell responses specific for nucleoprotein peptide NP262-270 bound to Mafa-A1*052:02 in macaques vaccinated with the whole particle vaccine were observed more promptly or more vigorously than those in macaques vaccinated with the split vaccine. These findings demonstrated that the vaccine derived from our virus library was effective for pandemic virus infection in macaques and that the whole particle vaccine conferred more effective memory and broader cross-reactive immune responses to macaques against pandemic influenza virus infection than did the split vaccine.
  • Naoki Nomura, Yoshihiro Sakoda, Kosuke Soda, Masatoshi Okamatsu, Hiroshi Kida
    JOURNAL OF VETERINARY MEDICAL SCIENCE 74 (4) 441 - 447 0916-7250 2012/04 [Refereed][Not invited]
     
    H9N2 influenza viruses circulate in wild birds and poultry in Eurasian countries, and have been isolated from pigs and humans in China. H9N2 viruses isolated from birds, pigs and humans have been classified into three sublineages based on antigenic and genetic features. Chicken antisera to H9N2 viruses of the Korean sublineage reacted with viruses of different sublineages by the hemagglutination-inhibition test. A test vaccine prepared from a non-pathogenic A/duck/Hokkaido/49/1998 (H9N2) strain of the Korean sublineage, obtained from our influenza virus library, induced immunity in mice to reduce the impact of disease caused by the challenge with A/Hong Kong/1073/1999 (H9N2), which is of a different sublineage. The present results indicate that an inactivated whole virus vaccine prepared from a non-pathogenic influenza virus from the library could be used as an emergency vaccine during the early stage of a pandemic caused by H9N2 infection.
  • カモから分離されたH7インフルエンザウイルスのニワトリに対する病原性獲得メカニズム
    丸山 隼輝, 曽田 公輔, 岡松 正敏, 迫田 義博, 喜田 宏
    日本獣医学会学術集会講演要旨集 (公社)日本獣医学会 153回 229 - 229 1347-8621 2012/03
  • Yoshihiro Sakoda, Hiroshi Ito, Yuko Uchida, Masatoshi Okamatsu, Naoki Yamamoto, Kosuke Soda, Naoki Nomura, Saya Kuribayashi, Shintaro Shichinohe, Yuji Sunden, Takashi Umemura, Tatsufumi Usui, Hiroichi Ozaki, Tsuyoshi Yamaguchi, Toshiyuki Murase, Toshihiro Ito, Takehiko Saito, Ayato Takada, Hiroshi Kida
    JOURNAL OF GENERAL VIROLOGY 93 (3) 541 - 550 0022-1317 2012/03 [Refereed][Not invited]
     
    H5N1 highly pathogenic avian influenza virus (HPAIV) was reintroduced and caused outbreaks in chickens in the 2010-2011 winter season in Japan, which had been free from highly pathogenic avian influenza (HPAI) since 2007 when HPAI outbreaks occurred and were controlled. On 14 October 2010 at Lake Ohnuma, Wakkanai, the northernmost part of Hokkaido, Japan, H5N1 HPAIVs were isolated from faecal samples of ducks flying from their nesting lakes in Siberia. Since then, in Japan, H5N1 HPAIVs have been isolated from 63 wild birds in 17 prefectures and caused HPAI outbreaks in 24 chicken farms in nine prefectures by the end of March in 2011. Each of these isolates was genetically closely related to the HPAIV isolates at Lake Ohnuma, and those in China, Mongolia, Russia and Korea, belonging to genetic clade 2.3.2.1. In addition, these isolates were genetically classified into three groups, suggesting that the viruses were transmitted by migratory water birds through at least three different routes from their northern territory to Japan. These isolates were antigenic variants, which is consistent with selection in poultry under the immunological pressure induced by vaccination. To prevent the perpetuation of viruses in the lakes where water birds nest in summer in Siberia, prompt eradication of HPAIVs in poultry is urgently needed in Asian countries where HPAI has not been controlled.
  • Naoki Nomura, Yoshihiro Sakoda, Mayumi Endo, Hiromi Yoshida, Naoki Yamamoto, Masatoshi Okamatsu, Kenji Sakurai, Nam Van Hoang, Long Van Nguyen, Huy Duc Chu, Tien Ngoc Tien, Hiroshi Kida
    ARCHIVES OF VIROLOGY 157 (2) 247 - 257 0304-8608 2012/02 [Refereed][Not invited]
     
    In the surveillance of avian influenza in Vietnam, 26 H9N2, 1 H3N2, 1 H3N8, 7 H4N6, 3 H11N3, and 1 H11N9 viruses were isolated from tracheal and cloacal swab samples of 300 domestic ducks in April 2009, and 1 H9N6 virus from 300 bird samples in March 2010. Out of the 27 H9 virus isolates, the hemagglutinins of 18 strains were genetically classified as belonging to the sublineage G1, and the other nine belonged to the Korean sublineage. Phylogenetic analysis revealed that one of the 27 H9 viruses was a reassortant in which the PB2 gene belonged to the Korean sublineage and the other seven genes belonged to the G1 sublineage. Three representative H9N2 viruses were intranasally inoculated into ducks, chickens, pigs, and mice. On the basis of experimental infection studies, it was found that each of the three viruses readily infected pigs and replicated in their upper respiratory tracts, and they infected chickens with slight replication. Viruses were recovered from the lungs of mice inoculated with two of the three isolates. The present results reveal that H9 avian influenza viruses are prevailing and genetic reassortment occurs among domestic ducks in Vietnam. It is recommended that careful surveillance of swine influenza with H9 viruses should be performed to prepare for pandemic influenza.
  • Matthias Liniger, Herve R. Moulin, Yoshihiro Sakoda, Nicolas Ruggli, Artur Summerfield
    VIROLOGY JOURNAL 9 7  1743-422X 2012/01 [Refereed][Not invited]
     
    Background: Influenza A viruses are well characterized to antagonize type I IFN induction in infected mammalian cells. However, limited information is available for avian cells. It was hypothesised that avian influenza viruses (AIV) with distinct virulence may interact differently with the avian innate immune system. Therefore, the type I IFN responses induced by highly virulent and low virulent H5N1 AIV and reassortants thereof were analysed in chicken cells. Results: The highly pathogenic (HP) AIV A/chicken/Yamaguchi/7/04 (H5N1) (Yama) did not induce type I IFN in infected chicken HD-11 macrophage-like cells. This contrasted with an NS1 mutant Yama virus (Yama-NS1(A144V)) and with the attenuated H5N1 AIV A/duck/Hokkaido/Vac-1/04 (Vac) carrying the haemagglutinin (HA) of the Yama virus (Vac-Yama/HA), that both induced type I IFN in these cells. The substitution of the NS segment from Yama with that from Vac in the Yama backbone resulted in induction of type I IFN secretion in HD-11 cells. However, vice versa, the Yama NS segment did not prevent type I IFN induction by the Vac-Yama/HA virus. This was different with the PB1/PB2/PA segment reassortant Yama and Vac-Yama/HA viruses. Whereas the Yama virus with the Vac PB1/PB2/PA segments induced type I IFN in HD-11 cells, the Vac-Yama/HA virus with the Yama PB1/PB2/PA segments did not. As reported for mammalian cells, the expression of H5N1 PB2 inhibited the activation of the IFN-beta promoter in chicken DF-1 fibroblast cells. Importantly, the Yama PB2 was more potent at inhibiting the IFN-beta promoter than the Vac PB2. Conclusions: The present study demonstrates that the NS1 protein and the polymerase complex of the HPAIV Yama act in concert to antagonize chicken type I IFN secretion in HD-11 cells. PB2 alone can also exert a partial inhibitory effect on type I IFN induction. In conclusion, the control of type I IFN induction by H5N1 HPAIV represents a complex phenotype that involves a particular viral gene constellation rather than a single viral protein. Collectively, these findings contribute to understand the high virulence of HPAIV H5N1 viruses observed in the chicken host.
  • Sakoda Y
    Uirusu 2 61 239 - 248 0042-6857 2011/12 [Refereed][Not invited]
  • Akira Sakurai, Namiko Nomura, Reiko Nanba, Takayuki Sinkai, Tsunehito Iwaki, Taminori Obayashi, Kazuhiro Hashimoto, Michiya Hasegawa, Yoshihiro Sakoda, Akihiro Naito, Yoshihito Morizane, Mitsugu Hosaka, Kunio Tsuboi, Hiroshi Kida, Akemi Kai, Futoshi Shibasaki
    JOURNAL OF VIROLOGICAL METHODS 178 (1-2) 75 - 81 0166-0934 2011/12 [Refereed][Not invited]
     
    The development of a rapid and sensitive system for detecting influenza viruses is a high priority for controlling future epidemics and pandemics. Quantitative real-time PCR is often used for detecting various kinds of viruses; however, it requires more than 2 h per run. Detection assays were performed with super high-speed RT-PCR (SHRT-PCR) developed according to a newly designed heating system. The new method uses a high-speed reaction (18 s/cycle; 40 cycles in less than 20 min) for typing influenza viruses. The detection limit of SHRT-PCR was 1 copy/reaction and 10(-1) plaque-forming unit/reaction for viruses in culture supernatants during 20 min. Using SHRT-PCR, 86 strains of influenza viruses isolated by the Tokyo Metropolitan Institute of Public Health were tested; the results showed 100% sensitivity and specificity for each influenza A and B virus, and swine-origin influenza virus. Twenty-seven swabs collected from the pharyngeal mucosa of outpatients were also tested, showing positive signs for influenza virus on an immunochromatographic assay; the results between SHRT-PCR and immunochromatography exhibited 100% agreement for both positive and negative results. The rapid reaction time and high sensitivity of SHRT-PCR makes this technique well suited for monitoring epidemics and pre-pandemic influenza outbreaks. (C) 2011 Published by Elsevier B.V.
  • Atsuhiko Wada, Yoshihiro Sakoda, Takayoshi Oyamada, Hiroshi Kida
    JOURNAL OF VIROLOGICAL METHODS 178 (1-2) 82 - 86 0166-0934 2011/12 [Refereed][Not invited]
     
    H5N1, a highly pathogenic avian influenza virus (HPAIV), has become a serious epizootic threat to the poultry population in Asia. In addition, significant numbers of human cases of HPAIV infection have been reported to date. To prevent the spread of HPAIV among humans and to allow for timely medical intervention, a rapid and high sensitive method is needed to detect and subtype the causative HPAIVs. In the present study, a silver amplification technique used in photographic development was combined with immunochromatography technologies and a highly sensitive and rapid diagnostic test to detect the hemagglutinin of H5 influenza viruses was developed. The sensitivity of the test kit was increased 500 times by silver amplification. The sensitivity of the method was more than 10 times higher than those of conventional rapid influenza diagnostic tests, which detect viral nucleoproteins. The diagnostic system developed in the present study can therefore provide rapid and highly sensitive results and will be useful for diagnosis of H5 HPAIV infection in humans and animals. (C) 2011 Elsevier B.V. All rights reserved.
  • Masayuki Motoshima, Masatoshi Okamatsu, Shingo Asakura, Saya Kuribayashi, Sugar Sengee, Damdinjav Batchuluun, Mika Ito, Yukiko Maeda, Mariko Eto, Yoshihiro Sakoda, Ruuragchaa Sodnomdarjaa, Hiroshi Kida
    ARCHIVES OF VIROLOGY 156 (8) 1379 - 1385 0304-8608 2011/08 [Refereed][Not invited]
     
    A/equine/Kanazawa/1/2007 (H3N8), A/equine/Hokkaido/I828/2008 (H3N8) and A/equine/Mongolia/1/2008 (H3N8) were isolated from infected horses. A/equine/Yokohama/aq19/2009 (H3N8) and A/equine/Yokohama/aq13/2010 (H3N8) were isolated from horses imported from Canada and Belgium examined at the Animal Quarantine Service in Yokohama, Japan. In the present study, these five isolates were genetically and antigenically analyzed. Phylogenetic analysis of hemagglutinin (HA) and neuraminidase (NA) genes showed that three isolates from horses in Japan and imported from Canada belonged to the same branch, clade 1 of the Florida sublineage, while the isolates from horses in Mongolia and imported from Belgium belonged to another branch, clade 2 of the Florida sublineage. Reactivity patterns of a panel of monoclonal antibodies to the HA of A/equine/Kanazawa/1/2007 (H3N8) with the five isolates indicate that the HAs of these viruses were antigenically similar to each other and to the reference strains A/equine/La Plata/1/1993 (H3N8) and A/equine/Avesta/1/1993 (H3N8). The present findings indicate that extensive antigenic variation has not accumulated among H3N8 influenza viruses in horses.
  • Masahiro Kajihara, Keita Matsuno, Edgar Simulundu, Mieko Muramatsu, Osamu Noyori, Rashid Manzoor, Eri Nakayama, Manabu Igarashi, Daisuke Tomabechi, Reiko Yoshida, Masatoshi Okamatsu, Yoshihiro Sakoda, Kimihito Ito, Hiroshi Kida, Ayato Takada
    JAPANESE JOURNAL OF VETERINARY RESEARCH 59 (2-3) 89 - 100 0047-1917 2011/08 [Refereed][Not invited]
     
    In 2010, an H5N1 highly pathogenic avian influenza virus (HPAIV) was isolated from feces of apparently healthy ducks migrating southward in Hokkaido, the northernmost prefecture of Japan. The H5N1 HPAIVs were subsequently detected in domestic and wild birds at multiple sites corresponding to the flyway of the waterfowl having stopovers in the Japanese archipelago. The Hokkaido isolate was genetically nearly identical to H5N1 HPAIVs isolated from swans in the spring of 2009 and 2010 in Mongolia, but less pathogenic in experimentally infected ducks than the 2009 Mongolian isolate. These findings suggest that H5N1 HPAIVs with relatively mild pathogenicity might be selected and harbored in the waterfowl population during the 2009-2010 migration seasons. Our data provide "early warning" signals for preparedness against the unprecedented situation in which the waterfowl reservoirs serve as perpetual sources and disseminators of HPAIVs.
  • Hiromi Yoshida, Yoshihiro Sakoda, Mayumi Endo, Masayuki Motoshima, Fumi Yoshino, Naoki Yamamoto, Masatoshi Okamatsu, Takahiro Soejima, Syouhei Senba, Hidetoshi Kanda, Hiroshi Kida
    JOURNAL OF VETERINARY MEDICAL SCIENCE 73 (6) 753 - 758 0916-7250 2011/06 [Refereed][Not invited]
     
    Migratory water birds are a natural reservoir for influenza A viruses. Viruses replicate in the intestines of ducks and are shed with the fecal materials. Virus isolation from collected fecal materials, therefore, is an integral part of the surveillance of avian influenza in water birds. In the present study, reverse transcription loop-mediated isothermal amplification (RT-LAMP) was assessed for its usefulness in detecting the RNA of influenza A viruses in fecal materials. It was found that, RT-LAMP specifically and sensitively detects the matrix gene of influenza A viruses. Influenza A viruses were isolated from the fecal materials in which viral RNA were detected by RT-LAMP in 35 min. The present findings indicate that RI-LAMP is useful as a high throughput screening method for field samples prior to virus isolation, allowing the processing of hundreds of samples per day.
  • Kosuke Soda, Ming-Chu Cheng, Hiromi Yoshida, Mayumi Endo, Shu-Hwae Lee, Masatoshi Okamatsu, Yoshihiro Sakoda, Ching-Ho Wang, Hiroshi Kida
    JOURNAL OF VETERINARY MEDICAL SCIENCE 73 (6) 767 - 772 0916-7250 2011/06 [Refereed][Not invited]
     
    H5N2 viruses were isolated from cloacal swab samples of apparently healthy chickens in Taiwan in 2003 and 2008 during surveillance of avian influenza. Each of the viruses was eradicated by stamping out. The official diagnosis report indicated that the Intravenous Pathogenicity Indexes (IVPIs) of the isolates were 0.00 and 0.89, respectively, indicating that these were low pathogenic strains, although the hemagglutinin of the strain isolated in 2008 (Taiwan08) had multibasic amino acid residues at the cleavage site (PQRKKR/G). In the present study, these H5N2 viruses were assessed for their intravenous and intranasal pathogenicity for chickens. It was examined whether Taiwan08 acquires pathogenicity through consecutive passages in chickens. Intravenous pathogenicity of Taiwan08 depended upon the age of the chickens used for the IVPI test; all of the eight-week-old chickens intravenously inoculated with Taiwan08 showed clinical signs but survived for ten days post inoculation (IVPI=0.68), whereas all the six-week-old chickens died (IVPI=1.86). Taiwan08-P8, which were passaged in chickens for eight times, killed all the eight-week-old chickens (IVPI=2.36). The four-week-old chickens died after intranasal inoculation of Taiwan08-P8, indicating that Taiwan08 must have become highly pathogenic during circulation in chicken flocks. These results emphasize the importance of a stamping out policy for avian influenza even if the IVPI of the causal virus is low.
  • Naoki Nomura, Yoshihiro Sakoda, Kosuke Soda, Masatoshi Okamatsu, Hiroshi Kida
    INFLUENZA AND OTHER RESPIRATORY VIRUSES 5 363 - 366 1750-2640 2011/05 [Refereed][Not invited]
  • Kosuke Soda, Shingo Asakura, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida
    INFLUENZA AND OTHER RESPIRATORY VIRUSES 5 272 - 276 1750-2640 2011/05 [Refereed][Not invited]
  • Eiji Miyagawa, Hiroyuki Kogaki, Yoshiaki Uchida, Nobuyuki Fujii, Takashi Shirakawa, Yoshihrio Sakoda, Hiroshi Kida
    JOURNAL OF VIROLOGICAL METHODS 173 (2) 213 - 219 0166-0934 2011/05 [Refereed][Not invited]
     
    Three anti-H5 influenza virus monoclonal antibody (mAb) clones, IFH5-26, IFH5-115 and IFH5-136, were obtained by immunising a BALB/C mouse with inactivated A/duck/Hokkaido/Vac-1/04 (H5N1). These mAbs were found to recognise specifically the haemagglutinin (HA) epitope of the influenza H5 subtypes by western blotting with recombinant HAs; however, these mAbs have no neutralising activity for A/duck/Hokkaido/84/02 (H5N3) or A/Puerto Ric/8/34 (H1N1). Each epitope of these mAbs was a conformational epitope that was formed from the regions located between 46 to 60 amino acids (aa) and 312 to 322 aa for IFH5-115, from 101 to 113 aa and 268 to 273 aa for IFH5-136 and from 61 to 80 aa and 290 to 300 aa for IFH5-26. The epitopes were located in the loop regions between the receptor region and alpha-helix structure in haemagglutinin 1 (HA1). Influenza A virus H5-specific rapid immunochromatographic test kits were tested as solid phase antibody/alkaline phosphate-conjugated mAb in the following three combinations: IFH5-26/IFH5-115, IFH5-136/IFH5-26 and IFH5-136/IFH5-115. In every combination, only influenza A H5 subtypes were detected. For effective clinical application, rapid dual discrimination immunochromatographic test kits in combination with H5 HA-specific mAb, IFA5-26 and IFA5-115 and the influenza A NP NP-specific mAb, FVA2-11, were developed. The dual discrimination immunochromatographic tests kits detected influenza A virus H5 subtypes as H5 line-positive and all influenza A subtypes as A line-positive simultaneously. The dual discrimination immunochromatographic test kits may be useful for discriminating highly pathogenic avian influenza A H5N1 viruses from seasonal influenza A virus, as well as for confirming influenza infection status in human, avian and mammalian hosts. (C) 2011 Elsevier B.V. All rights reserved.
  • Norikazu Isoda, Yoshihiro Sakoda, Masatoshi Okamatsu, Yoshimi Tsuda, Hiroshi Kida
    ARCHIVES OF VIROLOGY 156 (4) 557 - 563 0304-8608 2011/04 [Refereed][Not invited]
     
    The avian influenza vaccine strain A/duck/Hokkaido/Vac-1/2004 (H5N1) (Vac-1) was found to be pathogenic in chicken embryos (CEs). In order to decrease the pathogenicity of Vac-1 in CEs, a series of reassortant viruses was generated between Vac-1 and A/Puerto Rico/8/1934 (H1N1) (PR8), and their pathogenicity and growth potential were compared in CEs. The results indicated that either the PB1 or PA protein was responsible for the pathogenicity of Vac-1 in CEs. The HA titers of the allantoic fluids of CEs inoculated with the recombinant H5N1 viruses, of which pathogenicity was lower than that of the recombinant Vac-1 prepared by reverse genetics in CEs, were equivalent to those of CEs inoculated with the recombinant Vac-1. One of the reassortant viruses, rg-PR8-PA/Vac-1 (H5N1), in which the PA gene was replaced with the corresponding gene of PR8, yielded allantoic fluids with the same HA titer as that of Vac-1, indicating that this reassortant should be a good candidate as an improved vaccine strain.
  • Kosuke Soda, Shingo Asakura, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida
    VIROLOGY JOURNAL 8 64  1743-422X 2011/02 [Refereed][Not invited]
     
    Background: Outbreaks of avian influenza (AI) caused by infection with low pathogenic H9N2 viruses have occurred in poultry, resulting in serious economic losses in Asia and the Middle East. It has been difficult to eradicate the H9N2 virus because of its low pathogenicity, frequently causing in apparent infection. It is important for the control of AI to assess whether the H9N2 virus acquires pathogenicity as H5 and H7 viruses. In the present study, we investigated whether a non-pathogenic H9N2 virus, A/chicken/Yokohama/aq-55/2001 (Y55) (H9N2), acquires pathogenicity in chickens when a pair of di-basic amino acid residues is introduced at the cleavage site of its HA molecule. Results: rgY55sub (H9N2), which had four basic amino acid residues at the HA cleavage site, replicated in MDCK cells in the absence of trypsin after six consecutive passages in the air sacs of chicks, and acquired intravenous pathogenicity to chicken after four additional passages. More than 75% of chickens inoculated intravenously with the passaged virus, rgY55sub-P10 (H9N2), died, indicating that it is pathogenic comparable to that of highly pathogenic avian influenza viruses (HPAIVs) defined by World Organization for Animal Health (OIE). The chickens inoculated with the virus via the intranasal route, however, survived without showing any clinical signs. On the other hand, an avirulent H5N1 strain, A/duck/Hokkaido/Vac-1/2004 (Vac1) (H5N1), acquired intranasal pathogenicity after a pair of di-basic amino acid residues was introduced into the cleavage site of the HA, followed by two passages by air sac inoculation in chicks. Conclusion: The present results demonstrate that an H9N2 virus has the potential to acquire intravenous pathogenicity in chickens although the morbidity via the nasal route of infection is lower than that of H5N1 HPAIV.
  • Naoki Yamamoto, Yoshihiro Sakoda, Masayuki Motoshima, Fumi Yoshino, Kosuke Soda, Masatoshi Okamatsu, Hiroshi Kida
    VIROLOGY JOURNAL 8 65  1743-422X 2011/02 [Refereed][Not invited]
     
    Background: Infection with H5N1 highly pathogenic avian influenza viruses (HPAIVs) of domestic poultry and wild birds has spread to more than 60 countries in Eurasia and Africa. It is concerned that HPAIVs may be perpetuated in the lakes in Siberia where migratory water birds nest in summer. To monitor whether HPAIVs circulate in migratory water birds, intensive surveillance of avian influenza has been performed in Mongolia and Japan in autumn each year. Until 2008, there had not been any H5N1 viruses isolated from migratory water birds that flew from their nesting lakes in Siberia. In autumn 2009, A/mallard/Hokkaido/24/09 (H5N1) (Mal/Hok/24/09) was isolated from a fecal sample of a mallard (Anas platyrhynchos) that flew from Siberia to Hokkaido, Japan. The isolate was assessed for pathogenicity in chickens, domestic ducks, and quails and analyzed antigenically and phylogenetically. Results: No clinical signs were observed in chickens inoculated intravenously with Mal/Hok/24/09 (H5N1). There was no viral replication in chickens inoculated intranasally with the isolate. None of the domestic ducks and quails inoculated intranasally with the isolate showed any clinical signs. There were no multiple basic amino acid residues at the cleavage site of the hemagglutinin (HA) of the isolate. Each gene of Mal/Hok/24/09 (H5N1) is phylogenetically closely related to that of influenza viruses isolated from migratory water birds that flew from their nesting lakes in autumn. Additionally, the antigenicity of the HA of the isolate was similar to that of the viruses isolated from migratory water birds in Hokkaido that flew from their northern territory in autumn and different from those of HPAIVs isolated from birds found dead in China, Mongolia, and Japan on the way back to their northern territory in spring. Conclusion: Mal/Hok/24/09 (H5N1) is a non-pathogenic avian influenza virus for chickens, domestic ducks, and quails, and is antigenically and genetically distinct from the H5N1 HPAIVs prevailing in birds in Eurasia and Africa. H5 viruses with the HA gene of HPAIV had not been isolated from migratory water birds in the surveillance until 2009, indicating that H5N1 HPAIVs had not become dominant in their nesting lakes in Siberia until 2009.
  • Rozanah Asmah Abdul Samad, Yoshihiro Sakoda, Yoshimi Tsuda, Edgar Simulundu, Rashid Manzoor, Masatoshi Okamatsu, Kimihito Ito, Hiroshi Kida
    JAPANESE JOURNAL OF VETERINARY RESEARCH 59 (1) 15 - 22 0047-1917 2011/02 [Refereed][Not invited]
     
    Recent introduction of H5N1 highly pathogenic avian influenza virus (HPAIV) in wild birds from poultry in Eurasia signaled the possibility that this virus may perpetuate in nature. Surveillance of avian influenza especially in migratory birds, therefore, has been conducted to provide information on the viruses brought by them to Hokkaido, Japan, from their nesting lakes in Siberia in autumn. During 2008-2009, 62 influenza viruses of 21 different combinations of hemagglutinin (HA) and neuraminidase (NA) subtypes were isolated. Up to September 2010, no HPAIV has been found, indicating that H5N1 HPAIV has not perpetuated at least dominantly in the lakes where ducks nest in summer in Siberia. The PB2 genes of 54 influenza viruses out of 283 influenza viruses isolated in Hokkaido in 2000-2009 were phylogenetically analysed. None of the genes showed close relation to those of H5N1 HPAIVs that were detected in wild birds found dead in Eurasia on the way back to their northern territory in spring.
  • Rozanah Asmah Abdul Samad, Naoki Nomura, Yoshimi Tsuda, Rashid Manzoor, Masahiro Kajihara, Daisuke Tomabechi, Takashi Sasaki, Norihide Kokumai, Toshiaki Ohgitani, Masatoshi Okamatsu, Ayato Takada, Yoshihiro Sakoda, Hiroshi Kida
    JAPANESE JOURNAL OF VETERINARY RESEARCH 59 (1) 23 - 29 0047-1917 2011/02 [Refereed][Not invited]
     
    Inactivated influenza virus vaccine prepared from a non-pathogenic influenza virus strain A/duck/Hokkaido/Vac-1/2004 (H5N1) from the virus library conferred protective immunity to chickens against the challenge of antigenically drifted highly pathogenic avian influenza virus (HPAIV), A/whooper swan/Hokkaido/1/2008 (H5N1). The efficacy of the vaccine was comparable to that prepared from genetically modified HPAIV strain Delta RRRRK rg-A/whooper swan/Mongolia/3/2005 (H5N1), which is more antigenically related to the challenge virus strain, in chickens.
  • Fujiko Minami, Makoto Nagai, Mika Ito, Tatsuhiko Matsuda, Hikaru Takai, Yoshiko Jinkawa, Takeshi Shimano, Michiko Hayashi, Yoshihisa Seki, Yoshihiro Sakoda, Katsuaki Sugiura, Hiroomi Akashi
    COMPARATIVE IMMUNOLOGY MICROBIOLOGY AND INFECTIOUS DISEASES 34 (1) 35 - 39 0147-9571 2011/01 [Refereed][Not invited]
     
    Bovine viral diarrhea virus (BVDV) field isolates show genetic and antigenic diversity. At least 14 subgenotypes of BVDV-1 and 4 of BVDV-2 have been identified in Artiodactyla worldwide. Of these, 6 subgenotypes of BVDV-1 and 1 of BVDV-2 have been isolated in Japan. Previously, we reported that each subgenotype virus expresses different antigenic characteristics. Here we investigated the reactivity of neutralizing antibodies against representative strains of Japanese BVDV subgenotypes using sera from 266 beef cattle to estimate the prevalence of this epidemic virus among cattle in Japan. Antibody titers at concentrations at least 4-fold higher than antibodies against other subgenotype viruses were considered subgenotype specific. Subgenotype-specific antibodies were detected from 117(80.7%) of 145 sera samples (69.7% against BVDV-1a, 1.4% against BVDV-1b, 8.3% against BVDV-1c, and 1.4% against BVDV-2a). The results suggest that neutralization tests are useful in estimating currently epidemic subgenotypes of BVDV in the field. (C) 2009 Elsevier Ltd. All rights reserved.
  • Natsumi Takeyama, Kenji Minari, Masahiro Kajihara, Norikazu Isoda, Ryuichi Sakamoto, Takashi Sasaki, Norihide Kokumai, Noriyasu Takikawa, Rikiya Shiraishi, Masaji Mase, Junko Hagiwara, Toshiaki Kodama, Takashi Imamura, Masashi Sakaguchi, Toshiaki Ohgitani, Akira Sawata, Masatoshi Okamatsu, Masatake Muramatsu, Kenji Tsukamoto, Zhifeng Lin, Kotaro Tuchiya, Yoshihiro Sakoda, Hiroshi Kida
    VETERINARY MICROBIOLOGY 147 (3-4) 283 - 291 0378-1135 2011/01 [Refereed][Not invited]
     
    H5 and H7 highly pathogenic avian influenza virus (HPAIV) represent a major global concern in poultries and human health. Avian influenza (AI) vaccines are available but not preferred for field applications, primarily because vaccination interferes with sero-surveillances of AIV infection. To overcome the problem, ELISA systems using nonstructural protein 1 (NS1) of AIV as antigens (NS1-ELISA) have been developed to measure anti-NS1 antibodies that are raised in AIV-infected but not in vaccinated chickens. However, some AI-vaccinated chickens having a weak anti-virus immune response may subsequently be infected with AIV and spread the virus. This raises a concern for the validity of NS1-ELISA to detect AIV infection in previously vaccinated chickens. In this study, we developed NS1-ELISA and assessed its feasibility to detect HPAIV infection in chickens previously immunized with H5 or H7 AI vaccines. The results indicated that the NS1-ELISA could identify HPAIV infection in both unvaccinated and vaccinated chickens at 1 week after infection in correlation with results from time-consuming virus isolation tests. Taken together, the NS1-ELISA system would be valuable tool to define HPAIV infection when AI vaccine program is in place. (C) 2010 Elsevier B.V. All rights reserved.
  • Yuko Uchida, Katsushi Kanehira, Masaji Mase, Nobuhiro Takemae, Chiaki Watanabe, Tatsufumi Usui, Yoshikazu Fujimoto, Toshihiro Ito, Manabu Igarashi, Kimihito Ito, Ayato Takada, Yoshihiro Sakoda, Masatoshi Okamatsu, Yu Yamamoto, Kikuyasu Nakamura, Hiroshi Kida, Yasuaki Hiromoto, Tomoyuki Tsuda, Takehiko Saito
    VETERINARY MICROBIOLOGY 147 (1-2) 1 - 10 0378-1135 2011/01 [Refereed][Not invited]
     
    From February to March 2009, six strains of H7N6 subtype avian influenza virus were isolated from quails in three farms in Aichi prefecture in Japan. The isolates were shown to be low pathogenic for chicken by the examination performed using the "Manual of Standards for Diagnostic Tests and Vaccines" by World organisation for Animal Health (OIE). The deduced amino acid sequence at the cleavage site was PE (I/Q/L) PKRR (nucleotide sequences were cct gaa (a/c) (t/a) a cc (a/g) aaa aga aga), suggesting persistence in domestic poultry for some time. The direct putative ancestor strain could not be elucidated by phylogenetic analysis of all genome segments of the quail isolates. Diverged date from a putative common ancestor in a non-rooted phylogenetic tree among quail viruses was estimated between March 2002 and July 2004. Three putative N-linked glycosylation sites resided in the vicinity of the receptor binding pocket of HA1 region. They are considered to decrease the reactivity of neutralizing antibody against the virus. Experiments for the infectivity and pathogenicity of a quail strain to poultry indicated that the quail isolate had higher infectivity to quails than chickens and ducks. Direct and dust-borne and/or droplet-borne transmissions among quail were proven in quails with and without direct contact with experimentally infected quails. The virus is seldom transmitted among chickens either directly or indirectly, and indirect transmission from infected quails to chickens was not observed. The pathogenicity of the quail strain for mammalian, pig and mouse was low, although it could replicate in those animals. (C) 2010 Elsevier B.V. All rights reserved.
  • Masatoshi Okamatsu, Tomohisa Tanaka, Naoki Yamamoto, Yoshihiro Sakoda, Takashi Sasaki, Yoshimi Tsuda, Norikazu Isoda, Norihide Kokumai, Ayato Takada, Takashi Umemura, Hiroshi Kida
    VIRUS GENES 41 (3) 351 - 357 0920-8569 2010/12 [Refereed][Not invited]
     
    In April and May 2008, whooper swans (Cygnus cygnus) were found dead in Hokkaido in Japan. In this study, an adult whooper swan found dead beside Lake Saroma was pathologically examined and the identified H5N1 influenza virus isolates were genetically and antigenically analyzed. Pathological findings indicate that the swan died of severe congestive edema in the lungs. Phylogenetic analysis of the HA genes of the isolates revealed that they are the progeny viruses of isolates from poultry and wild birds in China, Russia, Korea, and Hong Kong. Antigenic analyses indicated that the viruses are distinguished from the H5N1 viruses isolated from wild birds and poultry before 2007. The chickens vaccinated with A/duck/Hokkaido/Vac-1/2004 (H5N1) survived for 14 days after challenge with A/whooper swan/Hokkaido/1/2008 (H5N1), although a small amount of the challenge virus was recovered from the tissues of the birds. These findings indicate that H5N1 highly pathogenic avian influenza viruses are circulating in wild birds in addition to domestic poultry in Asia and exhibit antigenic variation that may be due to vaccination.
  • Yoshihiro Sakoda, Sengee Sugar, Damdinjav Batchluun, Tseren-Ochir Erdene-Ochir, Masatoshi Okamatsu, Norikazu Isoda, Kosuke Soda, Hiroki Takakuwa, Yoshimi Tsuda, Naoki Yamamoto, Noriko Kishida, Keita Matsuno, Eri Nakayama, Masahiro Kajihara, Ayaka Yokoyama, Ayato Takada, Ruuragchaa Sodnomdarjaa, Hiroshi Kida
    VIROLOGY 406 (1) 88 - 94 0042-6822 2010/10 [Refereed][Not invited]
     
    H5N1 highly pathogenic avian influenza (HPAI) viruses were isolated from dead wild waterfowl at Khunt, Erkhel, Doityn Tsagaan, Doroo, and Ganga Lakes in Mongolia in July 2005, May 2006, May 2009, July 2009, and May 2010, respectively. The isolates in 2005 and 2006 were classified into genetic clade 2.2, and those in 2009 and 2010 into clade 2.3.2. A/whooper swan/Mongolia/6/2009 (H5N1) experimentally infected ducks and replicated systemically with higher mortality than that of the isolates in 2005 and 2006. Intensive surveillance of avian influenza in migratory waterfowl flying from their nesting lakes in Siberia to Mongolia in every autumn indicate that HPAI viruses have not perpetuated at their nesting lakes until 2009. The present results demonstrate that wild waterfowl were sporadically infected with H5N1 HPAI viruses prevailing in domestic poultry in the southern Asia and died in Mongolia on the way back to their northern territory in spring. (C) 2010 Elsevier Inc. All rights reserved.
  • Kazuya Matsuda, Shintaro Kobayashi, Ken-ichiro Kameyama, Michiko Sato, Masateru Koiwa, Yoshihiro Sakoda, Hiroyuki Taniyama
    JOURNAL OF VETERINARY MEDICAL SCIENCE 72 (7) 903 - 907 0916-7250 2010/07 [Refereed][Not invited]
     
    Bovine viral diarrhea virus (BVDV) causes fetal brain malformations in ruminants when the fetuses are infected transplacentally in mid-pregnancy. In both cytopathic and non-cytopatic virus infections, viral lytic infection in actively replicating cells and interruption of vascular integrity have been suggested as the pathogenesis, but functional disturbance of infected neural developing cells has been unclear. In this study, we examined the effect of infection with non-cytopathic BVDV2 on the differentiation of neural stem/precursor cells isolated from the bovine fetus. In the process of differentiation to three types of neural cells, neurons, astrocytes and oligodendrocytes, virus infection significantly and selectively inhibited the differentiation of neural stem/precursor cells into the astrocytic lineage. This inhibition is possibly important for the pathogenesis of congenital brain malformations associated with non-cytopathic BVDV infection.
  • Takashi Sasaki, Norihide Kokumai, Toshiaki Ohgitani, Takashi Imamura, Akira Sawata, Zhifeng Lin, Yoshihiro Sakoda, Hiroshi Kida
    JOURNAL OF VETERINARY MEDICAL SCIENCE 72 (6) 819 - 821 0916-7250 2010/06 [Refereed][Not invited]
     
    It is known that antibody responses in chickens against invading organisms or antigens are considerably different among different lines. Thus, an avian influenza vaccine was prepared from inactivated whole particles of the virus of non-pathogenic strain A/duck/Hokkaido/Vac-1/04 (H5N1) using an oil adjuvant containing anhydromannitol-octadecenoate-ether and injected intramuscularly into each ten 10-week-old specific pathogen-free (SPF) white leghorn chickens and commercial layers of Julia and Boris-Brown to obtain comparative data for antibody responses until 6 weeks after vaccination. Despite significant partial differences of antibody titer between the chicken lines, this study clearly showed that the vaccine induced good and sufficient antibody response in both SPF chickens and commercial layers.
  • Fei Feng, Nobuaki Miura, Norikazu Isoda, Yoshihiro Sakoda, Masatoshi Okamatsu, Hiroshi Kida, Shin-Ichiro Nishimura
    BIOORGANIC & MEDICINAL CHEMISTRY LETTERS 20 (12) 3772 - 3776 0960-894X 2010/06 [Refereed][Not invited]
     
    We designed and synthesized novel trivalent anti-influenza reagents. Sialyllactose was located at the terminal of each valence which aimed to block each receptor-binding site of the hemagglutinin (HA) trimer on the surface of the virus. Structural analyses were carried out with a model which was constructed with a computer simulation. A previously reported cyclic glycopeptide blocker [Ohta, T.; Miura, N.; Fujitani, N.; Nakajima, F.; Niikura, K.; Sadamoto, R.; Guo, C.-T.; Suzuki, T.; Suzuki, Y.; Monde, K.; Nishimura, S.-I. Angew. Chem. Int. Ed., 2003, 42, 5186] bound to the HA in the model. The analyses suggest that the glutamine residue in the cyclic peptide bearing Neu5A alpha 2,3Gal beta 1,4Glc trisaccharide via a linker interacts with the Gln189 in HA through hydrogen bonding. The present anti-influenza reagents likely interact with a glutamine residue included in the vicinity of Gln189. A plague reduction assay of the influenza virus, A/PR/8/1934 (H1N1),was performed in MDCK cells to evaluate for the synthesized compounds to inhibit viral replication. One of the compounds showed approximately 85% inhibition at the concentration of 400 mu M at 4 degrees C. (C) 2010 Elsevier Ltd. All rights reserved.
  • Ming-Chu Cheng, Kosuke Soda, Ming-Shiuh Lee, Shu-Hwae Lee, Yoshihiro Sakoda, Hiroshi Kida, Ching-Ho Wang
    AVIAN DISEASES 54 (2) 885 - 893 0005-2086 2010/06 [Refereed][Not invited]
     
    During the surveillance of avian influenza, an H5N2 influenza A virus was isolated from a cloacal swab sample of an apparently healthy chicken in Taiwan in October 2008. It was found that the HA of the virus had a pair of dibasic amino acid residues at the cleavage site, which might be a marker of highly pathogenic avian influenza virus. However, the intravenous pathogenicity index of the isolate was 0.89, indicating that the virus was approaching high pathogenicity in chickens. Virus isolation was negative in 2916 birds from 146 farms in a 3-km radius around the farm where the virus was isolated. Genetic analysis of the eight segments of the isolate indicated that the isolated virus was a reassortant whose HA and NA gene segments belonged to the American lineage and internal genes to the Eurasian lineage.
  • Tomohisa Tanaka, Yuji Sunden, Yoshihiro Sakoda, Hiroshi Kida, Kenji Ochiai, Takashi Umemura
    JOURNAL OF NEUROVIROLOGY 16 (2) 125 - 132 1355-0284 2010/04 [Refereed][Not invited]
     
    Influenza virus-associated encephalopathy (IAE) is a highly mortal neural complication of influenza A virus (IAV) infection, mostly affecting children younger than 5 years old, and the brain pathology of IAE is characterized by peracute brain edema with evidence of an impaired blood-brain barrier. The pathogenesis of IAE is unknown, but hypercytokinemia of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, and IL-6 is suspected of playing a central role in the development of IAE. Because the brain pathology of IAE is similar to that of septic encephalopathy due to endotoxemia, the effect of combined treatment of IAV and lipopolysaccharide (LPS) was tested using suckling mice. The results show that pulmonary infection with non-neurotropic IAV enhanced the neuropathogenicity of LPS and induced encephalopathy that was similar to IAE with respect to the occurrence of central nervous system (CNS) histopathology and the absence of direct infection of IAV in the brain. Influenza A virus also increased blood-brain barrier (BBB) permeability and induced inflammatory cytokines in the blood. These results suggested that the mice treated with IAV+LPS are possible animal models of IAE, and that hypercytokinemia and/or the involvement of endotoxemia in IAV infection are possible causes of IAE.
  • Taichiro Miyake, Kosuke Soda, Yasushi Itoh, Yoshihiro Sakoda, Hirohito Ishigaki, Tomoya Nagata, Hideaki Ishida, Misako Nakayama, Hiroichi Ozaki, Hideaki Tsuchiya, Ryuzo Torii, Hiroshi Kida, Kazumasa Ogasawara
    JOURNAL OF MEDICAL PRIMATOLOGY 39 (1) 58 - 70 0047-2565 2010/02 [Refereed][Not invited]
     
    Background Highly pathogenic avian influenza virus (HPAIV) infection has a high mortality rate in humans. Secondary bacterial pneumonia with HPAIV infection has not been reported in human patients, whereas seasonal influenza viruses sometimes enhance bacterial pneumonia, resulting in substantial morbidity and mortality. Therefore, if HPAIV infection were accompanied by bacterial infection, an increase in mortality would be expected. We examined whether a vaccine against HPAIV prevents severe morbidity caused by mixed infection with HPAIV and bacteria. Methods H7N7 subtype of HPAIV and Streptococcus pneumoniae were inoculated into cynomolgus macaques with or without vaccination of inactivated whole virus particles. Results Vaccination against H7N7 HPAIV decreased morbidity caused by HPAIV and pneumonia caused by S. pneumoniae. Bacterial replication in lungs was decreased by vaccination against HPAIV, although the reduction in bacterial colonies was not significant. Conclusions Vaccination against HPAIV reduces pneumonia caused by bacterial superinfection and may improve prognosis of HPAIV-infected patients.
  • Yasushi Itoh, Hiroichi Ozaki, Hirohito Ishigaki, Yoshihiro Sakoda, Tomoya Nagata, Kosuke Soda, Norikazu Isoda, Taichiro Miyake, Hideaki Ishida, Kiyoko Okamoto, Misako Nakayama, Hideaki Tsuchiya, Ryuzo Torii, Hiroshi Kida, Kazumasa Ogasawara
    VACCINE 28 (3) 780 - 789 0264-410X 2010/01 [Refereed][Not invited]
     
    Development of H7N7 highly pathogenic avian influenza virus (HPAIV) vaccines is an urgent issue since human cases of infection with this subtype virus have been reported and most humans have no immunity against H7N7 viruses. We made an H7N7 vaccine combining components from an influenza virus library of non-pathogenic type A influenza viruses Antibody and T cell recall responses specific against the vaccine strain were elicited by subcutaneous inoculation with the whole virus particle vaccine with or without alum as an adjuvant in cynomolgus macaques. No significant difference was observed in magnitude of antibody responses between vaccination with alum and vaccination without alum, though vaccination with alum induced longer recall responses of CD8(+) T cells than did vaccination without alum. After challenge with a subtype of H7N7 HPAIV, the virus was detected in nasal swabs of unvaccinated macaques for 8 days but only for I day in the animals vaccinated either with or without alum, although the macaques vaccinated with alum showed elevated body temperature more briefly after infection. These findings demonstrated that this H7N7 HPAIV strain is pathogenic to macaques and that the vaccine conferred protective immunity to macaques against H7N7 HPAIV infection. (C) 2009 Elsevier Ltd. All rights reserved.
  • Yoshitaka Kashima, Mizuho Ikeda, Yasushi Itoh, Yoshihiro Sakoda, Tomoya Nagata, Taichiro Miyake, Kosuke Soda, Hiroichi Ozaki, Misako Nakayama, Hitomi Shibuya, Masatoshi Okamatsu, Hirohito Ishigaki, Hideaki Ishida, Toshihiro Sawai, Yoshihiro Kawaoka, Hiroshi Kida, Kazumasa Ogasawar
    VACCINE 27 (52) 7402 - 7408 0264-410X 2009/12 [Refereed][Not invited]
     
    Outbreaks of highly pathogenic avian influenza viruses (HPAIVs) would cause disasters worldwide. Various strategies against HPAIVs are required to control damage. it is thought that the use of non-pathogenic avian influenza viruses as live vaccines will be effective in an emergency, even though there might be some adverse effects, because small amounts of live vaccines will confer immunity to protect against HPAIV infection. Therefore, live vaccines have the advantage of being able to be distributed worldwide soon after an outbreak. In the present study, we found that intranasal administration of a live H5N1 subtype non-pathogenic virus induced antibody and cytotoxic T lymphocyte responses and protected mice against H5N1 HPAIV infection. In addition, it was found that a small amount (100 PFU) of the live vaccine was as effective as 100 mu g (approximately 10(10-11) PFU of virus particles)of the inactivated whole particle vaccine in mice. Consequently, the use of live virus vaccines might be one strategy for preventing pandemics of HPAIVs in an emergency. (C) 2009 Elsevier Ltd. All rights reserved.
  • Manuela Ocana-Macchi, Michael Bel, Laurence Guzylack-Piriou, Nicolas Ruggli, Matthias Liniger, Kenneth C. McCullough, Yoshihiro Sakoda, Norikazu Isoda, Mikhail Matrosovich, Artur Summerfield
    JOURNAL OF VIROLOGY 83 (24) 12947 - 12955 0022-538X 2009/12 [Refereed][Not invited]
     
    Although current H5N1 highly pathogenic avian influenza viruses (HPAIV) are inefficiently transmitted to humans, infected individuals can suffer from severe disease, often progressing rapidly to acute respiratory distress syndrome and multiorgan failure. This is in contrast with the situation with human influenza viruses, which in immunocompetent individuals usually cause only a respiratory disease which is less aggressive than that observed with avian H5N1 viruses. While the biological basis of inefficient transmission is well documented, the mechanisms by which the H5N1 viruses cause fatal disease remain unclear. In the present study, we demonstrate that human pulmonary microvascular endothelial cells (hPMEC) had a clearly higher susceptibility to infection by H5N1 HPAIV than to infection by human influenza viruses. This was measurable by de novo intracellular nucleoprotein production and virus replication. It was also related to a relatively higher binding capacity to cellular receptors. After infection of hPMEC, cell activation markers E-selectin and P-selectin were upregulated, and the proinflammatory cytokines interleukin-6 and beta interferon were secreted. H5N1 virus infection was also associated with an elevated rate of cell death. Reverse genetics analyses demonstrated a major role for the viral hemagglutinin in this cell tropism. Overall, avian H5N1 viruses have a particular receptor specificity targeting endothelial cells that is different from human influenza viruses, and this H5N1 receptor specificity could contribute to disease pathogenesis.
  • Jae-Ho Shin, Yoshihiro Sakoda, Shiori Yano, Kenji Ochiai, Hiroshi Kida, Takashi Umemura
    JOURNAL OF VETERINARY MEDICAL SCIENCE 71 (10) 1331 - 1336 0916-7250 2009/10 [Refereed][Not invited]
     
    To evaluate the efficacy of intracerebral (IC) immunization, mice were immunized with a rabies vaccine by the subcutaneous (SC), intramuscular (IM) or IC route, and 10-fold the 50% lethal dose of rabies virus was inoculated into the hindleg of the immunized or non-immunized mice. The antibody titer in serum was elevated and boosted by additional immunization via all routes, but highest after the IC immunization followed by the IM and SC routes, in this order. Intracerebrally immunized mice were completely protected from death and the neurological signs of infection, whereas the IM or SC immunization only partly protected the mice. In mouse models, IC immunization is more effective at inducing a protective immune response against the transneural spread of rabies virus than IM or SC immunization.
  • Takashi Sasaki, Norihide Kokumai, Toshiaki Ohgitani, Ryuichi Sakamoto, Noriyasu Takikawa, Zhifeng Lin, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida
    VACCINE 27 (38) 5174 - 5177 0264-410X 2009/08 [Refereed][Not invited]
     
    An influenza vaccine was prepared from inactivated whole particles of the non-pathogenic strain A/duck/Hokkaido/Vac-1/04 (H5N1) virus using an oil adjuvant containing anhydromannitol-octaclecenoate-ether (AMOE). The vaccine was injected intramuscularly into five 4-week-old chickens, and 138 weeks after vaccination, they were challenged intranasally with 100 times 50% chicken lethal dose of the highly pathogenic avian influenza (HPAI) virus A/chicken/Yamaguchi/7/04 (H5N1). All 5 chickens survived without exhibiting clinical signs of influenza, although 2 days post-challenge, 3 vaccinated chickens shed limited titres of viruses in laryngopharyngeal swabs. (C) 2009 Elsevier Ltd. All rights reserved.
  • Yasushi Itoh, Kyoko Shinya, Maki Kiso, Tokiko Watanabe, Yoshihiro Sakoda, Masato Hatta, Yukiko Muramoto, Daisuke Tamura, Yuko Sakai-Tagawa, Takeshi Noda, Saori Sakabe, Masaki Imai, Yasuko Hatta, Shinji Watanabe, Chengjun Li, Shinya Yamada, Ken Fujii, Shin Murakami, Hirotaka Imai, Satoshi Kakugawa, Mutsumi Ito, Ryo Takano, Kiyoko Iwatsuki-Horimoto, Masayuki Shimojima, Taisuke Horimoto, Hideo Goto, Kei Takahashi, Akiko Makino, Hirohito Ishigaki, Misako Nakayama, Masatoshi Okamatsu, Kazuo Takahashi, David Warshauer, Peter A. Shult, Reiko Saito, Hiroshi Suzuki, Yousuke Furuta, Makoto Yamashita, Keiko Mitamura, Kunio Nakano, Morio Nakamura, Rebecca Brockman-Schneider, Hiroshi Mitamura, Masahiko Yamazaki, Norio Sugaya, M. Suresh, Makoto Ozawa, Gabriele Neumann, James Gern, Hiroshi Kida, Kazumasa Ogasawara, Yoshihiro Kawaoka
    NATURE 460 (7258) 1021 - U110 0028-0836 2009/08 [Refereed][Not invited]
     
    Influenza A viruses cause recurrent outbreaks at local or global scale with potentially severe consequences for human health and the global economy. Recently, a new strain of influenza A virus was detected that causes disease in and transmits among humans, probably owing to little or no pre-existing immunity to the new strain. On 11 June 2009 the World Health Organization declared that the infections caused by the new strain had reached pandemic proportion. Characterized as an influenza A virus of the H1N1 subtype, the genomic segments of the new strain were most closely related to swine viruses(1). Most human infections with swine-origin H1N1 influenza viruses (S-OIVs) seem to be mild; however, a substantial number of hospitalized individuals do not have underlying health issues, attesting to the pathogenic potential of S-OIVs. To achieve a better assessment of the risk posed by the new virus, we characterized one of the first US S-OIV isolates, A/California/04/09 ( H1N1; hereafter referred to as CA04), as well as several other S-OIV isolates, in vitro and in vivo. In mice and ferrets, CA04 and other S- OIV isolates tested replicate more efficiently than a currently circulating human H1N1 virus. In addition, CA04 replicates efficiently in non-human primates, causes more severe pathological lesions in the lungs of infected mice, ferrets and non-human primates than a currently circulating human H1N1 virus, and transmits among ferrets. In specific-pathogen-free miniature pigs, CA04 replicates without clinical symptoms. The assessment of human sera from different age groups suggests that infection with human H1N1 viruses antigenically closely related to viruses circulating in 1918 confers neutralizing antibody activity to CA04. Finally, we show that CA04 is sensitive to approved and experimental antiviral drugs, suggesting that these compounds could function as a first line of defence against the recently declared S- OIV pandemic.
  • Kanako Moritoh, Hideto Yamauchi, Atsushi Asano, Kentaro Yoshii, Hiroaki Kariwa, Ikuo Takashima, Norikazu Isoda, Yoshihiro Sakoda, Hiroshi Kida, Nobuya Sasaki, Takashi Agui
    JAPANESE JOURNAL OF VETERINARY RESEARCH 57 (2) 89 - 99 0047-1917 2009/08 [Refereed][Not invited]
     
    Mx1 (Myxovirus resistance protein) and Oas1b (Oligoadenylate synthetase-1), induced by type 1 interferon (IFN), play a role in early antiviral innate immunity by inhibiting the replication of viruses. In mice, Mx1 and Oas1b confer resistance to the infection of orthomyxoviruses including influenza viruses and flaviviruses including West Nile viruses, respectively. Laboratory mice have been used to study the mechanisms of the pathogenesis of these virus infections; however, it is possible that they are not a suitable model system to study these viruses, since most of the inbred laboratory mouse strains lack both genes. It has been reported that feral mouse-derived inbred strains show resistance to the infection of these viruses due to the presence of intact both genes. In this study, we generated congenic strains in which the Mx or Oas locus of the MSM/Ms (MSAI) mouce was introduced to the most widely used mouse strain, C57BL/6J (136). B6.MSM-Mx mice showed resistance to the infection of influenza virus but not of West Nile virus. On the other hand, B6.MSM-Oas mice showed resistance to the infection of West Nile virus but not of influenza virus. Our results indicate that Mx1 and Oas1b show highly antiviral specificity in mice possessing the same genetic background. Therefore, these congenic mice are useful for not only infection study but also investigation of host defense mechanism to these viruses.
  • Yoko Hara, Rie Hasebe, Yuji Sunden, Kenji Ochia, Eiichi Honda, Yoshihiro Sakoda, Takashi Umemura
    JOURNAL OF VETERINARY MEDICAL SCIENCE 71 (5) 595 - 601 0916-7250 2009/05 [Refereed][Not invited]
     
    Swine hemagglutinating encephalomyelitis virus (HEV) causes encephalomyelitis or vomiting and wasting disease in Suckling piglets. Neurotoropism of the virus has been demonstrated in previous in vivo studies. In the present study, we investigated the infectivity and propagation of HEV in comparison with those of pseudorabies virus (PRV), another neurotropic virus, using dorsal root ganglia cells of newborn mice containing nerve cells and non-neuronal cells. HEV infected nerve cells but did not infect non-neuronal cells, whereas PRV infected both cell types. By using cytoskeletal inhibitors, it was Suggested that propagation of HEV and PRV within and among nerve cells depended on microtubules and intermediate filaments of nerve cells, indicating that the viruses may be transported between the cell body and axonal terminals of neurons by fast axonal flow.
  • Yoshimi Tsuda, Norikazu Isoda, Yoshihiro Sakoda, Hiroshi Kida
    VIRUS RESEARCH 140 (1-2) 194 - 198 0168-1702 2009/03 [Refereed][Not invited]
     
    Many influenza A viruses form plaques on Madin-Darby canine kidney (MDCK) cells in the presence of trypsin. A/duck/Siberia/272/1998 (H13N6) (Sib272), however, does not form plaque on MDCK cells. After three blind passages of the strain on MDCK cells, plaque-forming variant was obtained and designated as A/duck/Siberia/272PF/1998 (H13N6) (Sib272PF). Genetic and functional analyses of Sib272 and Sib272PF revealed that amino acid substitutions, F3L of the HA2 subunit and T379K of the PB1, were responsible for plaque formation of Sib272PF by enhancing fusion and polymerase activities, respectively. (c) 2009 Elsevier B.V. All rights reserved.
  • Rashid Manzoor, Yoshihiro Sakoda, Naoki Nomura, Yoshimi Tsuda, Hiroichi Ozaki, Masatoshi Okamatsu, Hiroshi Kida
    JOURNAL OF VIROLOGY 83 (4) 1572 - 1578 0022-538X 2009/02 [Refereed][Not invited]
     
    It has been shown that not all but most of the avian influenza viruses replicate in the upper respiratory tract of pigs (H. Kida et al., J. Gen. Virol. 75: 2183-2188, 1994). It was shown that A/chicken/Yamaguchi/7/2004 (H5N1) [Ck/Yamaguchi/04 (H5N1)] did not replicate in pigs (N. Isoda et al., Arch. Virol. 151: 1267-1279, 2006). In the present study, the genetic basis for this host range restriction was determined using reassortant viruses generated between Ck/Yamaguchi/04 (H5N1) and A/swine/Hokkaido/2/1981 (H1N1) [Sw/Hokkaido/81 (H1N1)]. Two in vivo-generated single-gene reassortant virus clones of the H5N1 subtype (virus clones 1 and 2), whose PB2 gene was of Sw/Hokkaido/81 (H1N1) origin and whose remaining seven genes were of Ck/Yamaguchi/04 (H5N1) origin, were recovered from the experimentally infected pigs. The replicative potential of virus clones 1 and 2 was further confirmed by using reassortant virus (rg-Ck-Sw/PB2) generated by reverse genetics. Interestingly, the PB2 gene of Ck/Yamaguchi/04 (H5N1) did not restrict the replication of Sw/Hokkaido/81 (H1N1), as determined by using reassortant virus rg-Sw-Ck/PB2. The rg-Sw-Ck/PB2 virus replicated to moderate levels and for a shorter duration than parental Sw/Hokkaido/81 (H1N1). Sequencing of two isolates recovered from the pigs inoculated with rg-Sw-Ck/PB2 revealed either the D256G or the E627K amino acid substitution in the PB2 proteins of the isolates. The D256G and E627K mutations enhanced viral polymerase activity in the mammalian cells, correlating with replication of virus in pigs. These results indicate that the PB2 protein restricts the growth of Ck/Yamaguchi/04 (H5N1) in pigs.
  • Takashi Sasaki, Norikazu Isoda, Kosuke Soda, Ryuichi Sakamoto, Kazue Saijo, Junko Hagiwara, Norihide Kokumai, Toshiaki Ohgitani, Takashi Imamura, Akira Sawata, Zhifeng Lin, Yoshihiro Sakoda, Hiroshi Kida
    JAPANESE JOURNAL OF VETERINARY RESEARCH 56 (4) 189 - 198 0047-1917 2009/02 [Refereed][Not invited]
     
    Test vaccines comprised of inactivated water-in-oil emulsions containing various antigen levels were prepared using a non-pathogenic H5N1 avian influenza (AI) virus, A/duck/Hokkaido/Vac-1/04 (H5N1). The potencies of these test vaccines were evaluated by two experiments. In the first experiment, the triangular relationship among the antigen levels of test vaccines, the hemagglutination inhibition (HI) antibody response, and the protective effect against challenge with a highly pathogenic avian influenza (HPAI) virus, A/chicken/Yamaguchi/7/04 (H5N1), was confirmed. Then lasting immunity of chickens after a single-shot vaccination was confirmed in the second experiment. As a result, complete protection after the challenge was observed in chickens immunized by test vaccines with an antigen level of 160 HA units/dose or higher. Thus, it was ascertained that the minimum antigen level in the AI vaccine was 160 RA units/dose, and the minimum HI antibody titer that could protect chickens from HPAI virus infection-related death was considered to be 1:16. Dose-dependent III antibody responses were observed in chickens after the vaccination. Thus, 640 RA units/dose was thought to be similar to the optimal antigen level. Alternatively, the HI antibody titers of chickens, injected with the vaccine containing 640 HA units/dose, were maintained at 1:181 or higher for 100 weeks after the single-shot vaccination.
  • Nicolas Ruggli, Artur Summerfield, Ana R. Fiebach, Laurence Guzylack-Piriou, Oliver Bauhofer, Catherine G. Lamm, Sandro Waltersperger, Keita Matsuno, Luzia Liu, Markus Gerber, Kyung H. Choi, Martin A. Hofmann, Yoshihiro Sakoda, Jon-Duri Tratschin
    JOURNAL OF VIROLOGY 83 (2) 817 - 829 0022-538X 2009/01 [Refereed][Not invited]
     
    Pestiviruses prevent alpha/beta interferon (IFN-alpha/beta) production by promoting proteasomal degradation of interferon regulatory factor 3 (IRF3) by means of the viral N-pro nonstructural protein. N-pro is also an autoprotease, and its amino-terminal coding sequence is involved in translation initiation. We previously showed with classical swine fever virus (CSFV) that deletion of the entire N-pro gene resulted in attenuation in pigs. In order to elaborate on the role of the N-pro-mediated IRF3 degradation in classical swine fever pathogenesis, we searched for minimal amino acid substitutions in N-pro that would specifically abrogate this function. Our mutational analyses showed that degradation of IRF3 and autoprotease activity are two independent but structurally overlapping functions of N-pro. We describe two mutations in N-pro that eliminate N-pro-mediated IRF3 degradation without affecting the autoprotease activity. We also show that the conserved standard sequence at these particular positions is essential for N-pro to interact with IRF3. Surprisingly, when these two mutations are introduced independently in the backbones of highly and moderately virulent CSFV, the resulting viruses are not attenuated, or are only partially attenuated, in 8- to 10-week-old pigs. This contrasts with the fact that these mutant viruses have lost the capacity to degrade IRF3 and to prevent IFN-alpha/beta induction in porcine cell lines and monocyte-derived dendritic cells. Taken together, these results demonstrate that contrary to previous assumptions and to the case for other viral systems, impairment of IRF3-dependent IFN-alpha/beta induction is not a prerequisite for CSFV virulence.
  • Masatoshi Okamatsu, Yoshihiro Sakoda, Noriko Kishida, Norikazu Isoda, Hiroshi Kida
    ARCHIVES OF VIROLOGY 153 (12) 2189 - 2195 0304-8608 2008/12 [Refereed][Not invited]
     
    The hemagglutinins (HAs) of H9 influenza viruses isolated from birds and mammals of different species were antigenically and genetically analyzed. Antigenic variants were selected from A/swine/Hong Kong/10/98 (H9N2) and A/duck/Hokkaido/13/00 (H9N2) in the presence of monoclonal antibodies (MAbs). Based on the reactivity patterns of these mutants with a panel of MAbs, at least five non-overlapping antigenic sites were defined using eight MAbs which recognized seven distinct epitopes on the H9 HA molecule. Based on the reactivity patterns with the panel of monoclonal antibodies, 21 H9N2 virus strains isolated from birds and mammals were divided into 7 antigenically distinct groups. The present findings indicate that it is important to monitor the antigenic variation in H9 influenza viruses. The panel of MAbs in the present study, thus, should be useful for detailed antigenic analysis of the H9 HAs for epidemiological studies, the selection of vaccine strains, and diagnosis.
  • Kosuke Soda, Hiroichi Ozaki, Yoshihiro Sakoda, Norikazu Isoda, Yoshinari Haraguchi, Saori Sakabe, Noritaka Kuboki, Noriko Kishida, Ayato Takada, Hiroshi Kida
    ARCHIVES OF VIROLOGY 153 (11) 2041 - 2048 0304-8608 2008/11 [Refereed][Not invited]
     
    In order to prepare H5N1 influenza virus vaccine, the hemagglutinins (HAs) of 14 H5 virus isolates from water birds in Asia were antigenically and genetically analyzed. Phylogenetic analysis of the H5 HA genes revealed that 13 isolates belong to Eurasian and the other one to North American lineages. Each of the deduced amino acid sequences of the HAs indicated a non-pathogenic profile. Antigenic analysis using a panel of monoclonal antibodies recognizing six different epitopes on the HA of A/duck/Pennsylvania/10218/1984 (H5N2) and chicken antiserum to an H5N1 reassortant strain generated between A/duck/Mongolia/54/2001 (H5N2) and A/duck/Mongolia/47/2001 (H7N1), [R(Dk/Mong-Dk/Mong) (H5N1)] showed that the HAs of highly pathogenic avian influenza (HPAI) viruses currently circulating in Asia were antigenically closely related to those of the present isolates from water birds. Mice subcutaneously injected with formalin-inactivated R(Dk/Mong-Dk/Mong) were protected from challenge with 100 mouse lethal dose of A/Viet Nam/1194/2004 (H5N1). The present results support the notion that the H5 isolates and the reassortant H5N1 strain should be useful for vaccine preparation.
  • Rashid Manzoor, Yoshihiro Sakoda, Aaron Mweene, Yoshimi Tsuda, Noriko Kishida, Gui-Rong Bai, Ken-Ichiro Kameyama, Norikazu Isoda, Kosuke Soda, Michiko Naito, Hiroshi Kida
    VIRUS GENES 37 (2) 144 - 152 0920-8569 2008/10 [Refereed][Not invited]
     
    During 2000-2007, 218 influenza viruses of 28 different combinations of HA (H1-H13) and NA (N1-N9) subtypes were isolated from fecal samples of free-flying water birds at two distant lakes in Hokkaido, Japan. Phylogenic analysis of the matrix (M) genes of 67 strains, selected on the basis of their subtype combinations, revealed that A/duck/Hokkaido/W95/2006 (H10N8) was a reassortant whose M gene belonged to North American non-gull-avian and the other seven genes to Eurasian non-gull-avian lineages. The M genes of other 65 strains belonged to Eurasian non-gull-avian and the one to Eurasian-gull lineages. The M genes of 65 strains were grouped into three different sublineages, indicating that influenza viruses circulating in different populations of free-flying water birds have evolved independently in nature.
  • Rashid Manzoor, Yoshihiro Sakoda, Aaron Mweene, Yoshimi Tsuda, Noriko Kishida, Gui-Rong Bai, Ken-Ichiro Kameyama, Norikazu Isoda, Kosuke Soda, Michiko Naito, Hiroshi Kida
    Virus Genes 37 (2) 153  0920-8569 2008/10 [Refereed][Not invited]
  • Norikazu Isoda, Yoshihiro Sakoda, Noriko Kishida, Kosuke Soda, Saori Sakabe, Ryuichi Sakamoto, Takashi Imamura, Masashi Sakaguchi, Takashi Sasaki, Norihide Kokumai, Toshiaki Ohgitani, Kazue Saijo, Akira Sawata, Junko Hagiwara, Zhifeng Lin, Hiroshi Kida
    ARCHIVES OF VIROLOGY 153 (9) 1685 - 1692 0304-8608 2008/09 [Refereed][Not invited]
     
    A reassortant influenza virus, A/duck/Hokkaido/Vac-1/2004 (H5N1) (Dk/Vac-1/04), was generated between non-pathogenic avian influenza viruses isolated from migratory ducks in Asia. Dk/Vac-1/04 (H5N1) virus particles propagated in embryonated chicken eggs were inactivated with formalin and adjuvanted with mineral oil to form a water-in-oil emulsion. The resulting vaccine was injected intramuscularly into chickens. The chickens were challenged with either of the highly pathogenic avian influenza virus strains A/chicken/Yamaguchi/7/2004 (H5N1) or A/swan/Mongolia/3/2005 (H5N1) at 21 days post-vaccination (p. v.), when the geometric mean serum HI titers of the birds was 64 with the challenge virus strains. The vaccinated chickens were protected from manifestation of disease signs upon challenge with either of the highly pathogenic avian influenza viruses. However, challenge virus was recovered at low titers from the birds at 2 and 4 days post-challenge (p.c.). All 3 chickens challenged at 6 days p.v. died, whereas 3 chickens challenged at 8 days p.v. survived. These results indicate that the present vaccine confers clinical protection and reduction of virus shedding against highly pathogenic avian influenza virus challenge and should be useful as an optional tool in emergency cases.
  • Mika Ito, Makoto Nagai, Yuji Hayakawa, Hirofumi Komae, Naruto Murakami, Syouichi Yotsuya, Shingo Asakura, Yoshihiro Sakoda, Hiroshi Kida
    JOURNAL OF VETERINARY MEDICAL SCIENCE 70 (9) 899 - 906 0916-7250 2008/09 [Refereed][Not invited]
     
    In August 2007, an outbreak of equine influenza occurred among vaccinated racehorses with Japanese commercial equine influenza vaccine at Kanazawa Racecourse in Ishikawa prefecture in Japan. Apparent symptoms were pyrexia (38.2-41.0 degrees C) and nasal discharge with or without coughing, although approximately half of the infected horses were subclinical. All horses had been shot with a vaccine that contained two inactivated H3N8 influenza virus strains [A/equine/La Plata/93 (La Plata/93) of American lineage and A/ equine/Avesta/93 (Avesta/93) of European lineage] and an H7N7 strain (A/equine/Newmarket/1/77). Influenza virus, A/equine/ Kanazawa/1/2007 (H3N8) (Kanazawa/07), was isolated from one of the nasal swab samples of diseased horses. Phylogenetic analysis indicated that Kanazawa/07 was classified into the American sublineage Florida. In addition, four amino acid substitutions were found in the antigenic sites B and E in the HA1 subunit protein of Kanazawa/07 in comparison with that of La Plata/93. Hemagglutination-inhibition (HI) test using 16 serum samples from recovering horses revealed that 1.4- to 8-fold difference in titers between Kanazawa/ 07 and either of the vaccine strains. The present findings suggest that Japanese commercial inactivated vaccine contributed to reducing the morbidity rate and manifestation of the clinical signs of horses infected with Kanazawa/07 that may be antigenically different from the vaccine strains.
  • NS1-DIVAシステムを用いた国内製造鳥インフルエンザワクチン注射鶏のモニタリング
    竹山 夏実, 三成 健二, 坂元 隆一, 佐々木 崇, 瀧川 義康, 真瀬 昌司, 土屋 耕太郎, 岡松 正敏, 塚本 健司, 林 志鋒, 迫田 義博, 喜田 宏
    日本獣医学会学術集会講演要旨集 (公社)日本獣医学会 146回 193 - 193 1347-8621 2008/09
  • Noriko Kishida, Yoshihiro Sakoda, Mai Shiromoto, Gui-Rong Bai, Norikazu Isoda, Ayato Takada, Graeme Laver, Hiroshi Kida
    VIRUS GENES 37 (1) 16 - 21 0920-8569 2008/08 [Refereed][Not invited]
     
    To investigate the prevalence of influenza viruses in feral water birds in the Southern Hemisphere, fecal samples of terns were collected on Heron Island, Australia, in December 2004. Six H2N5 influenza viruses were isolated. This is the first report of the isolation of the H2 subtype from shore birds in Australia. Phylogenetic analysis revealed that the M gene belonged to the American lineage of avian influenza viruses and the other genes belonged to the Eurasian lineages, indicating that genetic reassortment occurs between viruses of Eurasian and American lineages in free flying birds in nature.
  • Rashid Manzoor, Yoshihiro Sakoda, Saori Sakabe, Tsuyoshi Mochizuki, Yasuharu Namba, Yoshimi Tsuda, Hiroshi Kida
    JOURNAL OF VETERINARY MEDICAL SCIENCE 70 (6) 557 - 562 0916-7250 2008/06 [Refereed][Not invited]
     
    As well as H5 highly pathogenic avian influenza viruses (HPAIV), H7 HPAIV strains have caused serious damages in poultry industries worldwide. Cases of bird-to-human transmission of H7 HPAIV have also been reported [I I]. On the outbreak of avian influenza, rapid diagnosis is critical not only for the control of HPAI but also for human health. In the present study, a rapid diagnosis kit based on immunochromatography for the detection of H7 hemagglutinin (HA) antigen of influenza A virus was developed using 2 monoclonal antibodies that recognize different epitopes on the H7 HAS. The kit detected each of the tested 15 H7 influenza virus strains and did not react with influenza A viruses of the other subtypes than H7 or other avian viral and bacterial pathogens. The kit detected H7 HA antigen in the swabs and tissue homogenates of the chickens experimentally infected with HPAIV strain A/chicken/Netherlands/2586/03 (H7N7). The results indicate that the present kit is specific and sensitive enough for the diagnosis of HPAI caused by H7 viruses, thus, recommended for the field application as a pen-site test kit.
  • Tomohisa Tanaka, Ginpei Tanoue, Masahiro Yamasaki, Ikuo Takashima, Yoshihiro Sakoda, Kenji Ochiai, Takashi Umemura
    JOURNAL OF VETERINARY MEDICAL SCIENCE 70 (6) 607 - 610 0916-7250 2008/06 [Refereed][Not invited]
     
    Many small wild birds died in the 2005-2006 wintertime in Hokkaido. Thirteen birds were pathologically examined and it was attempted to detect West Nile and influenza viruses from their organs. Consecutive pathological changes were fresh hemorrhage and acute circulatory failure. Viral detections were negative. Selective occurrence in wintertime, literature review and the results Of pathological and virological examinations Suggested chemical deicer poisoning as the cause of wild bird death. Chicks treated orally with deicer showed acute death and their pathological changes were similar to those of the wild birds. Because the chicks showed significant elevation of plasma Na concentration, plasma electrolyte analysis of the affected wild birds might be crucial to confirm Our tentative diagnosis.
  • Ken-ichiro Kameyama, Yoshihiro Sakoda, Keita Matsuno, Asako Ito, Motoshi Tajima, Shigeyuki Nakamura, Hiroshi Kida
    MICROBIOLOGY AND IMMUNOLOGY 52 (5) 277 - 282 0385-5600 2008/05 [Refereed][Not invited]
     
    The NS2-3 of BVDV is cleaved in cultured cells infected with cp BVDV but not in those infected with ncp BVDV when tested more than 10 hours post infection. However, it is not known whether cleavage of NS2-3 occurs in vivo. In the present study, cleavage of NS2-3 in cattle persistently infected with BVDV was investigated. All BVDV isolated from PI animals were of the ncp biotype, and NS2-3 proteins were detected in bovine fetal muscular cells infected with these viruses. On the other hand, in the leukocytes of those PI animals, NS3 proteins, products of the cleavage of NS2-3 proteins, were detected. In addition, the NS3 proteins were also detected in leukocytes artificially infected with ncp BVDV. These results reveal that the NS2-3 protein of BVDV is cleaved in leukocytes. Furthermore, NS3 proteins were detected in many tissues of PI cattle, such as lymphoid tissue, brain, thyroid, lung, and kidney. These results suggest that the NS2-3 protein of ncp BVDV cleaves in vivo.
  • Saori Sakabe, Yoshihiro Sakoda, Yoshinari Haraguchi, Norikazu Isoda, Kosuke Soda, Hiroki Takakuwa, Kazue Saijo, Akira Sawata, Katsumi Kume, Junko Hagiwara, Kotaro Tuchiya, Zhifeng Lin, Ryuichi Sakamoto, Takashi Imamura, Takashi Sasaki, Norihide Kokumai, Yoshihiro Kawaoka, Hiroshi Kida
    VACCINE 26 (17) 2127 - 2134 0264-410X 2008/04 [Refereed][Not invited]
     
    During 2001-2004, 41 H7 influenza viruses (2 H7N1 and 39 H7N7 strains) were isolated from fecal samples of migratory ducks that flew from Siberia in the autumn of each year to Japan and Mongolia. A phylogenetic analysis of the hemagglutinin (HA) genes of the nine representative isolates revealed that they belonged to the Eurasian Lineage and the deduced amino acid sequence at the cleavage site of the HAs represented apathogenic profiles. One of the H7 isolates A/duck/Mongolia/736/02 (H7N7) was chosen from these H7 isolates for the preparation of the test vaccine. To improve the growth potential of A/duck/Mongolia/ 736/02 (H7N7) in chicken embryos, A/duck/Hokkaido/Vac-2/04 (H7N7) was generated by genetic reassortment between A/duck/Mongolia/736/02 (H7N7) as the donor of the PB2, PB1, PA, HA, NA, and NS genes and A/duck/Hokkaido/49/98 (H9N2) as that of NP and M genes. The test vaccine was prepared as follows; A/duck/Hokkaido/Vac-2/04 (H7N7) was propagated in chicken embryos and the virus in the allantoic fluid was inactivated and adjuvanted to form an oil-in-water emulsion. The test vaccine conferred immunity to chickens, completely protecting the manifestation of clinical signs against the challenge with lethal dose of H7 highly pathogenic avian influenza virus. These results indicate that influenza viruses isolated from natural reservoirs are useful for vaccine strains. (C) 2008 Elsevier Ltd. All rights reserved.
  • Makoto Nagai, Michiko Hayashi, Mika Itou, Toyoko Fukutomi, Hiroomi Akashi, Hiroshi Kida, Yoshihiro Sakoda
    VIRUS GENES 36 (1) 135 - 139 0920-8569 2008/02 [Refereed][Not invited]
     
    A part of the nucleotide sequence of the 5' untranslated region (5'UTR) and E-rns region, and the genomic regions encoding for N-pro, Core, and E2 of So-like isolates and IS25CP/01 strain which belong to bovine viral diarrhea virus genotype 1 (BVDV-1) were determined and genetic comparisons were made with sequences of other BVDV subgenotypes. Phylogenetic analysis using the 5'UTR and N-pro revealed that So-like isolates and IS25CP/01 branched into independent phylogenetic branch. So-like isolates were clustered with Korean BVDV strains taken from DDBL/EMBL/GenBank in the 5'UTR. An additional two amino acid residues were found at the C terminal of the Core region of IS25CP/01. The similarity of amino acid sequence of E2 of So-like isolates and IS25CP/01 to the BVDV-1 reference strain NADL were 78.0-78.5 and 79.0, respectively. Cross-neutralization tests showed significant antigenic differences between So-like isolates and the others (Antigenic similarity (R) value: 2.2-8.8), and IS25CP/01 and the others (R value: 1.6-8.8). So-like viruses and IS25CP/01 differed from the thirteenth subgenotypes (1a-1m) reported by Jackova et al. (2007) and were classified as new genetic subtypes, BVDV-1n (So-like) and 1o (IS25CP/01).
  • Yasushi Itoh, Hiroichi Ozaki, Hideaki Tsuchiya, Kiyoko Okamoto, Ryuzo Torii, Yoshihiro Sakoda, Yoshihiro Kawaoka, Kazumasa Ogasawara, Hiroshi Kida
    VACCINE 26 (4) 562 - 572 0264-410X 2008/01 [Refereed][Not invited]
     
    In order to prepare for the emergence of pandemic influenza viruses, we have established an influenza virus library that contains non-pathogenic influenza A virus strains with 135 combinations of 15 hemagglutinin and 9 neuraminidase subtypes. In this study, we developed a vaccine against H5N1 highly pathogenic avian influenza (HPAI) virus infection in humans using a virus strain selected from the library. We examined its immunogenic potency using cynomolgus macaques as a primate model. Virus antigen-specific antibodies were elicited by intranasal or subcutaneous administration of inactivated whole virus particle vaccines. After challenge with an H5N1 HPAI virus isolate obtained from a Vietnamese patient, the virus was detected only on next day following inoculation in the nasal and/or tracheal. swabs of vaccinated macaques that were asymptomatic. On the other hand, the viruses were isolated from nasal and tracheal swabs from non-vaccinated macaques until day 5 and day 7 after inoculation of the H5N1 HPAI virus, respectively. Although six non-vaccinated macaques developed a high body temperature, and two of them lost their appetite after HPAI virus infection, they recovered by the end of the 12-day observation period and did not show the severe symptoms that have been reported in human H5N1 virus infection cases. This demonstrates that the vaccine prepared with the non-pathogenic H5N1 virus from our influenza virus library conferred protective immunity against H5N1 HPAI virus infection to macaques. (C) 2007 Elsevier Ltd. All rights reserved.
  • Kosuke Soda, Yoshihiro Sakoda, Norikazu Isoda, Masahiro Kajihara, Yoshinari Haraguchi, Hitomi Shibuya, Hiromi Yoshida, Takashi Sasaki, Ryuichi Sakamoto, Kazue Saijo, Junko Hagiwara, Hiroshi Kida
    JAPANESE JOURNAL OF VETERINARY RESEARCH 55 (2-3) 93 - 98 0047-1917 2008/01 [Refereed][Not invited]
     
    To establish vaccine strains of H5 and H7 influenza viruses, A/duck/Hokkaido/Vac-1/04 (H5N1) [Vac-1/04 (H5N1)], A/duck/Hokkaido/Vac-3/07 (H5N1) [Vac-3/07 (H5N1)], and A/duck/Hokkaido/ Vac-2/04 (H7N7) [Vac-2/04 (H7N7)] were generated from non-pathogenic avian influenza viruses isolated from migratory ducks. Vac-1/04 (H5N1) and Vac-3/07 (H5N1) were generated by genetic reassortment between H5N2 or H5N3 virus as an HA gene provider and H7N1 or H6N1 viruses as an NA gene provider. Vac-2/04 (H7N7) was a genetic reassortant obtained using H7N7 and H9 N2 viruses to give high growth character of the H9N2 virus in chicken embryonated eggs. The results of sequence analyses and experimental infections revealed that these H5N1 and H7N7 reassortant viruses were non-pathogenic in chickens and embryos, and had good growth potential in embryonated eggs. These viruses should be useful to develop vaccines against H5 and H7 highly pathogenic avian influenza viruses.
  • M. Malamo, K. Okazaki, Y. Sakoda, H. Kida
    VETERINARY RECORD 161 (25) 853 - 857 0042-4900 2007/12 [Refereed][Not invited]
     
    Monoclonal antibodies (mAbs) against a recombinant carboxyl terminus of the 34 kDa protein of Mycobacterium paratuberculosis were produced in mice. Two of the mAbs cross-reacted with Mycobacterium avium and Mycobacterium intracellulare in both an ELISA and immunoblot. The recombinant protein also reacted with polyclonal sera produced in rabbits against all three mycobacteria, indicating the presence of cross-reactive epitopes in the protein. To determine the reactivity of cattle sera against epitopes recognised by the mAbs, competition assays between bovine sera and the mAbs were carried out. Two mAbs were significantly inhibited by sera from cattle that were naturally infected with M paratuberculosis. The results indicate that epitopes on the carboxyl terminus of the 34 kDa protein common to M paratuberculosis, M avium and M intracellulare readily induce antibody production in naturally infected cattle. These epitopes reduce the diagnostic specificity of the carboxyl terminus of the 34 kDa protein, which was originally thought to contain only M paratuberculosis-specific epitopes.
  • Jae-Ho Shin, Yoshihiro Sakoda, Jae Hoon Kim, Kenji Ochiai, Takashi Umemura
    JOURNAL OF VETERINARY MEDICAL SCIENCE 69 (11) 1167 - 1169 0916-7250 2007/11 [Refereed][Not invited]
     
    Rabbits were immunized with inactivated influenza virus via the subarachnoidal (SA) or subcutaneous (SC) route, and the antibody titers in cerebrospinal fluid (CSF) and serum were assayed. There were no nervous signs or morphological lesions related to SA immunization. In the SC group, the antibody titer was elevated in serum, but not elevated in CSF. In the SA group, the antibody titer was significantly elevated in serum and even in CSF, and their antibody titers were much greater than in the SC group. The present results suggest that intrathecal immunization is more effective than SC immunization at inducing a protective immune response against the transneural spread of viruses.
  • Keita Matsuno, Yoshihiro Sakoda, Ken-ichiro Kameyama, Kyuzo Tamai, Asako Ito, Hiroshi Kida
    JOURNAL OF VETERINARY MEDICAL SCIENCE 69 (5) 515 - 520 0916-7250 2007/05 [Refereed][Not invited]
     
    The 475 strains of bovine viral diarrhea virus (BVDV) isolated from cattle in 12 prefectures of Japan in the last 7 years were phylo.genetically classified as BVDV-1 or BVDV-2 on the basis of the nucleotide sequence of the 5'-untransiated region. BVDV-1 strains were further subtyped as 1a (101 strains), 1b (163), 1c (128), 1j (3), and So CP/75-like (1), and all of the 79 BVDV-2 strains belonged to subtype 2a. These 2a BVDVs contain two isolates that had high nucleotide identities with those of highly pathogenic BVDV-2 strains reported in North America (Pellerin et al., 1994). However, acute infection with severe mortality like North American outbreak was not observed and most of the present BVDV-2 strains were isolated from persistently infected (PI) cattle showing mild or no clinical sign. Moreover, it was revealed that 61.5% of the 39 PI cattle with cytopathogenic BVDVs did not show typical mucosal disease and 54.6% of the 405 PI animals only with non-cytopathogenic BVDVs were apparently healthy. The present results indicate that the prevention of the infection with an appropriate vaccine and active surveillance covering healthy cattle are required for the control of BVD.
  • Oliver Bauhofer, Artur Summerfield, Yoshihiro Sakoda, Jon-Duri Tratschin, Martin A. Hofmann, Nicolas Ruggli
    JOURNAL OF VIROLOGY 81 (7) 3087 - 3096 0022-538X 2007/04 [Refereed][Not invited]
     
    Viruses have evolved a multitude of strategies to subvert the innate immune system by interfering with components of the alpha/beta interferon (IFN-alpha/beta) induction and signaling pathway. It is well established that the pestiviruses prevent IFN-alpha/beta induction in their primary target cells, such as epitheloidal and endothelial cells, macrophages, and conventional dendritic cells, a phenotype mediated by the viral protein N-pro. Central players in the IFN-alpha/beta induction cascade are interferon regulatory factor 3 (IRF3) and IRF7. Recently, it was proposed that classical swine fever virus (CSFV), the porcine pestivirus, induced the loss of IRF3 by inhibiting the transcription of IRF3 mRNA. In the present study, we show that endogenous IRF3 and IRF3 expressed from a cytomegallovirus (CMV) promoter are depleted in the presence of CSFV by means of N-pro, while CSFV does not inhibit CMV promoter-driven protein expression. We also demonstrate that CSFV does not reduce the transcriptional activity of the IRF3 promoter and does not affect the stability of IRF3 mRNA. In fact, CSFV N-pro induces proteasomal degradation of IRF3, as demonstrated by proteasome inhibition studies. Furthermore, N-pro coprecipitates with IRF3, suggesting that the proteasomal degradation of IRF3 is induced by a direct or indirect interaction with N-pro. Finally, we show that N-pro does not downregulate IRF7 expression.
  • Kei Fujii, Chiharu Kakumoto, Mari Kobayashi, Sachiko Saito, Tatsuya Kariya, Yukiko Watanabe, Yoshihiro Sakoda, Hiroshi Kida, Masatsugu Suzuki
    JOURNAL OF VETERINARY MEDICAL SCIENCE 69 (3) 259 - 263 0916-7250 2007/03 [Refereed][Not invited]
     
    For proper management and conservation of the Kuril harbor seal (Phoca vitulina stejnegeri) through disease control, serological analysis was performed for influenza A virus infection in free-ranging seals in Hokkaido, Japan. Serum samples were collected from seals at Nosappu (231 seals), Akkeshi (16) and Erimo (75), between 1998 and 2005, and were analyzed by ELISA. Antibodies to the influenza A virus were detected only in seals from Nosappu. The incidences were 11% (1/9), 3% (2/66), 12% (7/59) and 6% (5/77) in 1998, 2003, 2004 and 2005, respectively. These suggest sporadic infection. Because anti body-positive seals included juvenile seals in each year, the infections were considered to have been circulated since no later than the late 1990s until recent years. ELISA-positive sera were analyzed by hemagglutination inhibition (HI) tests to determine the subtypes. Antibodies to the H3 and H6 subtypes were detected in 10 and 2 sera, respectively. Two of the sera that had antibodies to the H6 subtype also had antibodies to the H3 subtype. These two seals were considered to have been infected with both the H3 and H6 subtypes. This is the first investigation to find antibodies to the H6 subtype in seals. Although the H6 subtype had been isolated only from avians, genetic analysis had suggested that the H6 subtype could become a novel mammalian pathogen. For definitive diagnosis, detection of the virus from the tissue or mucus of seals is required.
  • H5N2鳥インフルエンザウイルスを接種したSFP鶏における抗体応答の長期観察と野外感染例の解析
    岡松 正敏, 加茂前 仁弥, 棚橋 美和, 迫田 義博, 真瀬 昌司, 塚本 健司, 喜田 宏, 山口 成夫
    日本獣医学会学術集会講演要旨集 (公社)日本獣医学会 143回 195 - 195 1347-8621 2007/03
  • Stuart D. Blacksell, Naomi J. Bryant, Daniel H. Paris, Jenny A. Doust, Yoshihiro Sakoda, Nicholas P. J. Day
    CLINICAL INFECTIOUS DISEASES 44 (3) 391 - 401 1058-4838 2007/02 [Refereed][Not invited]
     
    A review was performed to determine the evidence base for scrub typhus indirect immunofluorescence assay ( IFA) methodologies and the criteria for positive results. This review included a total of 109 publications, which comprised 123 eligible studies for analysis ( 14 publications included 2 substudies). There was considerable underreporting of the IFA methodology and seropositivity criteria used, with most studies using a defined cutoff titer rather than an increase in the titer in paired samples. The choice of positivity cutoff titer varied by country and purpose of the IFA test. This variation limits the comparability of seroprevalence rates between studies and, more seriously, raises questions about the appropriateness of the cutoffs for positive IFA results chosen for diagnosis of acute scrub typhus infection. We suggest that the diagnosis of scrub typhus using IFA should be based on a >= 4- fold increase in the titer in paired serum samples and should only be based on a single sample titer when there is an adequate local evidence base.
  • Michiko Naito, Yoshihiro Sakoda, Takayuki Kamikawa, Yoshiki Nitta, Kazuhiko Hirose, Mitsuaki Sakashita, Satoru Kurokawa, Hiroshi Kida
    MICROBIOLOGY AND IMMUNOLOGY 51 (6) 593 - 599 0385-5600 2007 [Refereed][Not invited]
     
    Serum samples were collected from 938 pigs of 24 farms in Hokkaido, Kagoshima, and Okinawa prefectures in Japan in 2001-2005. Enzyme-linked immunosorbent assay (ELISA) was used for the detection of antibodies to LipL32 antigen which is common to Leptospira interrogans. Samples positive in ELISA were then investigated by microscopic agglutination test for the identification of causal leptospires. Antibodies specific to leptospires of serovars Copenhageni, Bratislava, Australis and Javanica were detected in serum samples of pigs from each of the three districts. In addition, antibodies to leptospires of serovars Autummalis and Thrassovi were predominantly detected in those from Kagoshima. The present study, thus, revealed that leptospires belonging to different serovars prevail in the pig population in Japan. In addition, it is the first detection of antibodies to leptospires belonging to serovars Javanica and Thrassovi in pigs in Japan.
  • Yoshimi Tsuda, Yoshihiro Sakoda, Saori Sakabe, Tsuyoshi Mochizuki, Yasuharu Namba, Hiroshi Kida
    MICROBIOLOGY AND IMMUNOLOGY 51 (9) 903 - 907 0385-5600 2007 [Refereed][Not invited]
     
    Highly pathogenic avian influenza (HPAI) caused by the H5N1 subtype has given rise to serious damage in poultry industries in Asia. The virus has expanded its geographical range to Europe and Africa, posing a great risk to human health as well. For the control of avian influenza, a rapid diagnosis by detecting the causative virus and identifying its subtype is essential. In the present study, a rapid diagnosis kit combining immunochromatography with enzyme immunoassay which detects the H5 HA antigen of influenza A virus was developed using newly established anti-H5 HA monoclonal antibodies. The present kit specifically detected all of the H5 influenza viruses tested, and did not react with the other HA subtypes. H5 HA antigens were detected from swabs and tissue homogenates of chickens infected with HPAI virus strain A/chicken/Yamaguchi/7/04 (H5N1) from 2 days post inoculation. The kit showed enough sensitivity and specificity for the rapid diagnosis of HPAI.
  • K. Kameyama, Y. Sakoda, K. Tamai, H. Igarashi, M. Tajima, T. Mochizuki, Y. Namba, H. Kida
    JOURNAL OF VIROLOGICAL METHODS 138 (1-2) 140 - 146 0166-0934 2006/12 [Refereed][Not invited]
     
    An immunochromatographic test was developed for rapid diagnosis of bovine viral diarrhea virus (BVDV) infections using monoclonal antibodies against the nonstructural protein, NS3, of the virus. The kit detected specifically the NS3 of various BVDV strains. Using the kit, leukocyte extracts of cattle infected persistently with BVDV were found positive while those of healthy cattle were negative. The sensitivity and specificity of this kit in compared with virus isolation were 100% and 97.2%, respectively. Furthermore, the test also gave positive results for calves infected acutely with BVDV in experimental infection. The BVDV antigen was detected in I ml of blood using a relatively simple procedure. This test kit should be useful for rapid diagnosis of BVD. (c) 2006 Elsevier B.V. All rights reserved.
  • Mumeka Malamo, Yoshihiro Sakoda, Hiroichi Ozaki, Hiroshi Kida
    JAPANESE JOURNAL OF VETERINARY RESEARCH 54 (2-3) 99 - 107 0047-1917 2006/11 [Refereed][Not invited]
     
    To develop ELISA to detect antibodies specific to Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis), the carboxyl termini of the 34 kDa proteins of M. paratuberculosis and Mycobacterium avium subsp. avium (M. avium) were expressed in Escherichia cola expression system. Antibodies specific to M. paratuberculosis were detected with the truncated 34 kDa protein of M. paratuberculosis in ELISA after pre-absorption of serum samples with the truncated 34 kDa protein of M. avium. All the serum samples from cattle confirmed to be infected with M. paratuberculosis were positive and those from healthy cattle were negative in the present ELISA system. These results indicate that the established ELISA detects antibodies specific to M. paratuberculosis with high specificity and sensitivity and is an useful tool for the screening of Johne's disease.
  • Kei Fujii, Hiroki Sato, Chiharu Kakumoto, Mari Kobayashi, Sachiko Saito, Tatsuya Kariya, Yukiko Watanabe, Yoshihiro Sakoda, Chieko Kai, Hiroshi Kida, Masatsugu Suzuki
    JAPANESE JOURNAL OF VETERINARY RESEARCH 54 (2-3) 109 - 117 0047-1917 2006/11 [Refereed][Not invited]
     
    Serological analysis was performed to detect morbillivirus infection in Kuril harbor seals in Hokkaido, Japan. Serum samples were collected from the seals at Nosappu (231 sera), Akkeshi (16), and Erimo (75) between 1998 and 2005. Antibodies to phocine distemper virus (PDV) were detected by ELISA in seals from Nosappu and Erimo. Antibodies to PDV were found in 56% (5/9) of the sampled seals from Nosappu in 1998, versus only 5% (3/66) for 2003, 1% (1/79) for 2004, and 1% (1/77) for 2005. These suggest epidemic caused by the virus in or before 1998. As antibody-positive seals included juvenile seals in 2003 and 2005, sporadic infections of the virus are thought to have occurred in recent years. In Erimo, antibodies to PDV were found in 50% (14/28) of sampled seals in 2004, versus only 13% (1/8) for 1999, 7 (1/15) for 2003, and 0 % (0/24) for 2005. These suggest sporadic infection by the virus before 2003 and the epizootic between after autumn in 2003, when samples of 2003 were collected, and 2004. Since antibodies to canine distemper virus (CDV) were detected in one adult seal from Nosappu in each year from 2003 to 2005, sporadic infections of the virus were suggested. There were no difference in incidence of seals with. antibodies to the viruses between males and females and between juveniles and adults.
  • N Isoda, Y Sakoda, N Kishida, GR Bai, K Matsuda, T Umemura, H Kida
    ARCHIVES OF VIROLOGY 151 (7) 1267 - 1279 0304-8608 2006/07 [Refereed][Not invited]
     
    Outbreaks of highly pathogenic avian influenza (HPAI) have been occurring in domestic poultry in Asia since 1996. In the beginning of 2004, HPAI outbreaks were caused by H5N1 virus in two farms and a group of pet chickens in different areas of Japan. In the present study, the pathogenicity of A/chicken/Yamaguchi/7/04 (H5N1), which had been isolated from a dead chicken during the first outbreak in Japan, was assessed in chickens, quails, budgerigars, ducklings, mice, and miniature pigs by experimental infection. The virus was highly pathogenic to all the birds tested. Mice were susceptible to infection with a low mortality rate and miniature pigs were resistant to infection with the virus.
  • K Kameyama, Y Sakoda, K Tamai, M Nagai, H Akashi, H Kida
    VIRUS RESEARCH 116 (1-2) 78 - 84 0168-1702 2006/03 [Refereed][Not invited]
     
    Cytopathogenic (cp) bovine viral diarrhea virus (BVDV) strain KS86-1cp was isolated from a cow persistently infected with non-cytopathogenic (ncp) BVDV strain KS86-1ncp after development of mucosal disease by superinfection with cp BVDV strain Nose. cp BVDV strains 799cp and 839cp were also isolated from independent cattle that developed mucosal disease by superinfection with cpBVDV KS86-1cp. In the present Study, genetic analysis revealed that the genes of cp BVDV strains 799cp and 839cp were chimeras between the genes of the persisting ncp BVDVs and that of super infecting KS86-1cp. The genetic recombination that generates 799cp occurred between the identical points in the N-PRO gene region. whereas genetic recombination that generates 839cp Occurred between different points in the N-PRO gene region. Both 799cp and 839cp were inherited Jiv gene of KS86-1cp strain and envelope protein genes of the persisting Viruses. In addition, neutralization test disclosed that antigenicities of 799cp, 839cp, and KS86-1cp were also similar to each persisting virus. These findings indicate that exogenous cp BVDV containing insertion of Jiv gene in the 5 terminal region can induce genetic recombination with the original ncp BVDV at different points in the N-PRO gene region, and those viruses have high potential to change those antigenicities and pathogenicities by RNA recombination. (c) 2005 Elsevier B.V. All rights reserved.
  • GR Bai, Y Sakoda, AS Mweene, N Fujii, H Minakawa, H Kida
    JOURNAL OF VETERINARY MEDICAL SCIENCE 68 (1) 35 - 40 0916-7250 2006/01 [Refereed][Not invited]
     
    To improve the sensitivity of a kit, ESPLINE (R) INFLUENZA A&B for rapid diagnosis of influenza by detecting influenza A or B virus specific nucleoproteins (NP), the ESPLINE (R) INFLUENZA A&B-N was developed by using newly established monoclonal antibodies (MAbs) to the respective NP molecule. MAbs FVA2-11 and FrB1-03 recognize the epitope on the amino acid region 59-130aa of the NP molecule of influenza A virus, and that on the region 72-191aa of the NP of influenza B virus, respectively. The new kit detected influenza A and B virus antigens with a detection limit of 10(2.0)-10(2.7) pfu/test, which is 4-1000 times higher than that of the original kit. Importantly, this kit detected each of influenza A viruses of the known hemagglutinin (HA) subtypes (H1-H15) including the H5N1 viruses recently isolated from human and avian sources in Asia. The kit also detected all of the 15 representative influenza B virus strains tested. The ESPLINE (R) INFLUENZA A&B-N is thus a rapid and highly sensitive and specific kit for the diagnosis of either influenza A or B virus infections.
  • Jae-Ho Shin, Yoshihiro Sakoda, Jae Hoon Kim, Tomohisa Tanaka, Hiroshi Kida, Takashi Kimura, Kenji Ochiai, Takashi Umemura
    MICROBIOLOGY AND IMMUNOLOGY 50 (10) 823 - 830 0385-5600 2006 [Refereed][Not invited]
     
    To evaluate the efficacy of intracerebral (IQ immunization, mice were immunized with formalin-inactivated pseudorabies virus (PRV) by either subcutaneous (SQ or IC injection, and then 10(6) plaque-forming units of PRV were introduced into the hindleg of the immunized or non-immunized mice by intramuscular injection. The antibody titer in serum was elevated and boosted by additional immunization via both the SC and IC routes, but was higher after IC immunization. Intracerebrally immunized mice were completely protected from mortality and neurological signs, whereas all the non-immunized and 80% of the subcutaneously immunized mice died after developing neurological signs. In mouse models, IC immunization is more effective at inducing a protective immune response against the transneural spread of PRV than SC immunization.
  • H Kida, Y Sakoda
    OIE/FAO International Scientific Conference on Avian Influenza 124 69 - 72 1424-6074 2006 [Refereed][Not invited]
     
    To prepare for the emergence of pandemic influenza in birds and mammals including humans, we have carried out global surveillance of avian influenza. Influenza A viruses of 48 combinations of 15 HA and 9 NA subtypes out of 135 theoretical combinations have been isolated from faecal samples of ducks in Alaska, Siberia, Mongolia, Taiwan, China and Japan. So far, viruses of 73 other combinations have been generated by genetic reassortment in chicken embryos. Thus, avian influenza viruses of 121 combinations of HA and NA subtypes have been stocked for use in vaccine and diagnosis. Their pathogenicity, antigenicity, genetic information, and yield in chicken embryo have been analysed and registered in the database.
  • Jae-Ho Shin, Yoshihiro Sakoda, Hoon Kim Jae, Tomohisa Tanaka, Hiroshi Kida, Takashi Kimura, Kenji Ochiai, Takashi Umemura
    Microbiology and Immunology 50 (10) 823 - 830 1348-0421 2006 [Refereed][Not invited]
     
    To evaluate the efficacy of intracerebral (IC) immunization, mice were immunized with formalin-inactivated pseudorabies virus (PRV) by either subcutaneous (SC) or IC injection, and then 106 plaque-forming units of PRV were introduced into the hindleg of the immunized or non-immunized mice by intramuscular injection. The antibody titer in serum was elevated and boosted by additional immunization via both the SC and IC routes, but was higher after IC immunization. Intracerebrally immunized mice were completely protected from mortality and neurological signs, whereas all the non-immunized and 80% of the subcutaneously immunized mice died after developing neurological signs. In mouse models, IC immunization is more effective at inducing a protective immune response against the transneural spread of PRV than SC immunization.
  • S Takeda, A Sbagyo, Y Sakoda, A Ishii, M Sawamura, K Sueoka, H Kida, K Mukasa, K Matsumoto
    BIOSENSORS & BIOELECTRONICS 21 (1) 201 - 205 0956-5663 2005/07 [Refereed][Not invited]
     
    Carbon nanotube sensors detected anti-hemagglutinin binding to immobilized hemagglutinins. An ultra-sensitive detection method for antibodies or antigens in serum is required. Hemagglutinins were immobilized on the reverse side of a carbon nanotube, thereby producing a source and a drain. Electrode pads covered each edge of the nanotube. The 1-V curves between the source and the drain were measured after incubation of anti-hemagglutinins with immobilized hemagglutinins in a buffered solution on the reverse side of the nanotube. The sensitivity of the CNT sensor was higher than that of an ELISA system. This method constitutes a new tool to analyze interaction among biomolecules on a substrate. (c) 2004 Elsevier B.V. All rights reserved.
  • N Kishida, Y Sakoda, N Isoda, K Matsuda, M Eto, Y Sunaga, T Umemura, H Kida
    ARCHIVES OF VIROLOGY 150 (7) 1383 - 1392 0304-8608 2005/07 [Refereed][Not invited]
     
    Four H5N1 highly pathogenic avian influenza (HPAI) viruses and an avirulent reassortant H5N1 virus were tested for their pathogenicity in domestic ducks. A/chicken/Yamaguchi/7/04 (H5N1) (Ck/Yamaguchi/04) isolated from a dead bird during the HPAI outbreak in Japan and A/duck/Yokohama/aq-10/03 (H5N1) (Dk/Yokohama/03) isolated from duck meat at a quarantine inspection for importation from China replicated in multiple organs including the brain of ducks. The ducks infected with Ck/Yamaguchi/04 did not show any clinical signs, while those infected with Dk/Yokohama/03 showed neurological signs. The ducks infected either with A/Hong Kong/483/97 (H5N1) orA/tern/SouthAfrica/61 (H5N3), or with an avirulent H5N1 reassortant, did not show any clinical signs. Virus-specific antibodies were detected in the sera of the ducks infected with each of the five strains tested, indicating that all of the viral strains infected and replicated in the birds. Dk/Yokohama/03 grew in multiple organs more rapidly than did Ck/Yamaguchi/04. Considerable titers of virus were detected in the brain of the ducks infected with Dk/Yokohama/03 and these birds showed neurological signs. The present results demonstrate that the pathogenicity of influenza viruses for ducks does not correlate with that for chickens and that replication of the virus in the brain is critical for ducks to show neurological signs.
  • N Odontsetseg, Y Sakoda, H Kida
    VETERINARY RECORD 157 (4) 120 - 121 0042-4900 2005/07 [Refereed][Not invited]
  • K Matsuda, T Shibata, Y Sakoda, H Kida, T Kimura, K Ochiai, T Umemura
    JOURNAL OF GENERAL VIROLOGY 86 (4) 1131 - 1139 0022-1317 2005/04 [Refereed][Not invited]
     
    Neural involvement following infections of influenza viruses can be serious. The neural transport of influenza viruses from the periphery to the central nervous system has been indicated by using mouse models. However, no direct evidence for neuronal infection has been obtained in vitro and the mechanisms of neural transmission of influenza viruses have not been reported. In this study, the transneural transmission of a neurotropic influenza A virus was examined using compartmentalized cultures of neurons from mouse dorsal root ganglia, and the results were compared with those obtained using the pseudorabies virus, a virus with well-established neurotransmission. Both viruses reached the cell bodies of the neurons via the axons. This is the first report on axonal transport of influenza A virus in vitro. In addition, the role of the cytoskeleton (microtubules, microfilaments and intermediate filaments) in the neural transmission of influenza virus was investigated by conducting cytoskeletal perturbation experiments. The results indicated that the transport of avian influenza A virus in the neurons was independent of microtubule integrity but was dependent on the integrity of intermediate filaments, whereas pseudorabies virus needed both for neural spread.
  • The vagus nerve is one route of transneural invasion for intranasally inoculated influenza A virus in mice
    Matsuda K, Shibata T, Sakoda Y, Kida H, Kimura T, Ochiai K, Umemura T
    Journal of General Virology 86 1131 - 1139 2005/04 [Refereed][Not invited]
  • Erratum: Serological evidence of the persistence of infection with Leptospira interrogans serovar hardjo in cattle in Mongolia (Microbiology and Immunology (2005) 49:9 (865-869))
    Namsraijav Odontsetseg, Yoshihiro Sakoda, Hiroshi Kida
    Microbiology and Immunology 49 (11) 1017 - 1018 0385-5600 2005
  • T Inoue, S Alexandersen, AT Clark, C Murphy, M Quan, SM Reid, Y Sakoda, HL Johns, GJ Belsham
    JOURNAL OF VIROLOGY 79 (1) 428 - 440 0022-538X 2005/01 [Refereed][Not invited]
     
    A major virulence determinant of swine vesicular disease virus (SVDV), an Enterovirus that causes an acute vesicular disease, has been mapped to residue 20 of the 2A protease. The SVDV 2A protease cleaves the ID-2A junction in the viral polyprotein, induces cleavage of translation initiation factor eIF4GI, and stimulates the activity of enterovirus internal ribosome entry sites (IRESs). The 2A protease from an attenuated strain of SVDV (Ile at residue 20) is significantly defective at inducing cleavage of eIF4GI and the activation of IRES-dependent translation compared to the 2A protease from a pathogenic strain (J1/73, Arg at residue 20), but the two proteases have similar ID-2A cleavage activities (Y. Sakoda, N. Ross-Smith, T. Inoue, and G. J. Belsham, J. Virol. 75:10643-10650, 2001). Residue 20 has now been modified to every possible amino acid, and the activities of each mutant 2A protease has been analyzed. Selected mutants were reconstructed into full-length SVDV cDNA, and viruses were rescued. The rate of virus growth in cultured swine kidney cells reflected the efficiency of 2A protease activity. In experimentally infected pigs, all four of the mutant viruses tested displayed much-reduced virulence compared to the J1/73 virus but a significant, albeit reduced, level of viral replication and excretion was detected. Direct sequencing of cDNA derived from samples taken early and late in infection indicated that a gradual selection-reversion to a more efficient protease occurred. The data indicated that extensive sequence change and selection may introduce a severe bottleneck in virus replication, leading to a decreased viral load and reduced or no clinical disease.
  • N Odontsetseg, Y Sakoda, H Kida
    MICROBIOLOGY AND IMMUNOLOGY 49 (9) 865 - 869 0385-5600 2005 [Refereed][Not invited]
     
    Serum samples were collected randomly from Mongol breed cattle in three geographically distinct provinces of Mongolia. Antibodies specific to Leptospira interrogans serovar Hardjo were detected by microscopic agglutination test (MAT) at titres of 100 or more in 80.4% (86/107) of the samples from Dornod Province, but in only 28.9% (13/45) in Arkhangai and 23.5% (12/51) in Khuvsgul Provinces, respectively. Treatment of 9 serum samples from Dornod, positive to serovar Hardjo in MAT and negative in the homologous immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA), with 2-mercaptoethanol (2-ME) indicated that those animals were recently infected.
  • GR Bai, Y Sakoda, AS Mweene, N Kishida, T Yamada, H Minakawa, H Kida
    MICROBIOLOGY AND IMMUNOLOGY 49 (12) 1063 - 1067 0385-5600 2005 [Refereed][Not invited]
     
    The ESPLINE(R) INFLUENZA A&B-N kit was evaluated for its applicability to the rapid diagnosis of influenza in chickens and pigs. The kit specifically detected viral antigens in tracheal swabs and tissue homogenates of the trachea, liver, spleen, and colon of chickens inoculated with a highly pathogenic avian influenza virus strain, A/chicken/Yamaguchi/7/04 (H5N1), at 48 hr post-inoculation (p.i.) as well as in the tracheal and cloacal swabs and tissue homogenates of dead chickens. For those infected with a low pathogenic strain, A/chicken/aq-Y-55/01 (H9N2), antigens were detected only in the samples from tracheal swabs and organs 1-4 days p.i. The kit also detected viral antigens in the nasal swabs of miniature pigs infected with swine and avian influenza viruses. The kit was found to be sensitive and specific enough for the rapid diagnosis of infections of influenza A virus in chickens and pigs.
  • N Kishida, Y Sakoda, M Eto, Y Sunaga, H Kida
    ARCHIVES OF VIROLOGY 149 (11) 2095 - 2104 0304-8608 2004/11 [Refereed][Not invited]
     
    H9N2 influenza viruses are frequently isolated from chicken meat and bone marrow imported from China to Japan since 2001. These isolates were experimentally inoculated into specific pathogen-free chickens intranasally. Viruses were recovered from the meat and bone marrow of birds showing no overt signs. On the other hand, chickens co-infected with H9N2 virus and either Staphylococcus aureus or Haemophilus paragallinarum showed clinical signs severer than those shown by birds infected only with the virus alone or each of the bacteria alone. In addition, H9N2 viruses were more efficiently recovered from the chickens co-infected with S. aureus or H. paragallinarum than those from the birds infected with only the virus. The present results indicate that co-infection of H9N2 influenza virus with S. aureus or H. paragallinarum enhances the replication of the virus in chickens, resulting in exacerbation of the H9N2 virus infection.
  • M Nagai, M Hayashi, S Sugita, Y Sakoda, M Mori, T Murakami, T Ozawa, N Yamada, H Akashi
    VIRUS RESEARCH 99 (2) 103 - 113 0168-1702 2004/02 [Refereed][Not invited]
     
    Phylogenetic analysis of the five different regions (5' non-coding region (5'NCR), N-pro, E2, NS3 and NS5B-3'NCR) of 48 Japanese and reported bovine viral diarrhea virus (BVDV) genomes was performed. Japanese BVDVs were segregated into BVDV1 subdivided into six subgroups and BVDV2. One isolate, So CP/75, isolated in 1975 and previously proposed as subgroup 1e according to its 5'NCR sequence, was quite unique and formed an independent lineage in the tree of any region. Another isolate, 190CP, obtained from an experimental mucosal disease case was classified as subgroup 1e, defined by Becher et al. in the 5'NCR, N-pro and E2 regions, whereas it was classified as subgroup la in the NS5B-3'NCR region. The genomic sequences of the American isolates ILLC and ILLNC obtained from the GenBank database were assigned into subgroup 1b in the 5'NCR, N-pro, E2 and NS5B-3'NCR regions, whereas they were assigned into subgroup la in the NS3 region, suggesting that recombination between the virus strains classified into different subgroups had occurred in an animal. These findings suggest that phylogenetic analysis of several genetic regions is useful for the further characterization of field BVDV isolates. (C) 2003 Elsevier B.V. All rights reserved.
  • H Aoki, Y Sakoda, S Nakamura, S Suzuki, A Fukusho
    JOURNAL OF VETERINARY MEDICAL SCIENCE 66 (2) 161 - 167 0916-7250 2004/02 [Refereed][Not invited]
     
    Pestiviruses can be distinguished as two biotypes, cytopathogenic (cp) and noncytopathogenic (noncp), by the morphological changes that they induce during growth in cultured cells. In this study, the cp phenotype of several classical swine fever viruses (CSFV) was evaluated by the detections of the nonstructural proteins NS2-3 and NS3 using immunoprecipitation and Western blotting in different porcine cell lines. Most CSFVs that showed the exaltation of Newcastle disease virus (END) phenomenon (END+ viruses) did not induce cytopathic effect (CPE)in any cell line, and detections of NS2-3 and NS3 showed a strong signal for NS2-3 in the END+ virus-infected cells. However, clear CPE was observed in serum-free cultured cells (FS-L3 and CPK-NS) infected with viruses that induce intrinsic interference but did not show the END phenomenon (END- viruses), and signal of NS3 was strongly detected than that of NS2-3 in these cells at 72 hr after infection. As the results of the analysis of FS-L3 cells infected with ALD (END+ virus) and ALD-END- virus (END- virus) at several incubations, the signal of NS3 detected was strengthened with CPE that become evident progressively. These results suggest that CPE is associated with the accumulation of NS3, which is promoted in serum-free cell lines infected with END- viruses. Thus, indicating there is a close relationship between CPE and the quantity of NS3 produced in END- CSFV infection.
  • Y Sakoda, T Ito, K Okazaki, A Takada, Y Ito, K Tamai, M Okamatsu, KF Shortridge, RG Webster, H Kida
    OPTIONS FOR THE CONTROL OF INFLUENZA V 1263 674 - 677 0531-5131 2004 [Refereed][Not invited]
     
    For the prediction of future influenza pandemics, global surveillance of avian influenza has been continuing since 1991 and carried out in Russia, Mongolia, China and Japan from 2000 to 2003. Influenza virus isolates of 50 combinations of HA and NA subtypes have been identified and 3 strains selected from each of those are stocked. In addition, 47 other combinations have been generated by standard genetic reassortment procedure in the laboratory. Since we have already shown that influenza viruses have been fully adapted to ducks and cause no disease signs and are in evolutionary stasis in their natural reservoirs, virus isolates from ducks are ideal as vaccine strains. Thus, influenza viruses of 97 combinations of HA and NA subtypes are now available as vaccine strain candidates against emerging pandemic influenza in humans, domestic animals and poultry. (C) 2003 Elsevier B.V. All rights reserved.
  • JH Liu, K Okazaki, H Ozaki, Y Sakoda, QM Wu, FY Chen, H Kida
    AVIAN PATHOLOGY 32 (5) 551 - 560 0307-9457 2003/10 [Refereed][Not invited]
     
    Ten H9N2 influenza virus strains isolated from diseased chickens in different farms in China during 1995 to 1999 were antigenically and genetically characterized. The haemagglutinins of the isolates were not related to those of A/quail/ Hong Kong/G1/97 ( H9N2) (Qa/HK/G1/97), but were closely related to that of A/chicken/ Hong Kong/G9/97 ( H9N2) (Ck/HK/G9/97). The neuraminidase of these isolates had a deletion of three amino acid residues at positions 63 to 65 as compared with those of Ck/HK/G9/97, while that of Qa/HK/G1/97 lacked two amino acids at positions 38 and 39. The PB2 genes of the isolates were not related to those of Qa/HK/G1/ 97 or Ck/HK/G9/97, but showed some relationship to that of A/duck/Hong Kong/Y439/97 ( H9N2) (Dk/HK/Y439/ 97). The PB1 genes of the isolates were not related to those of the three representative strains. The PA, NP, M, and NS genes of the isolates belonged to the same lineage as those of Ck/HK/G9/97, and were distinct from those of Qa/HK/G1/ 97 and Dk/HK/Y439/97. The present results indicate that H9N2 influenza viruses prevalent in chicken populations in China belong genetically to one lineage and are distinct from Qa/HK/G1/ 97, presumed to be the donor of the internal protein genes of the highly pathogenic H5N1 influenza virus in Hong Kong in 1997.
  • M Nagai, Y Sakoda, M Mori, M Hayashi, H Kida, H Akashi
    JOURNAL OF GENERAL VIROLOGY 84 (2) 447 - 452 0022-1317 2003/02 [Refereed][Not invited]
     
    The cytopathogenic bovine viral diarrhoea virus (cp BVDV) strain KS86-1 cp was isolated from a calf persistently infected with the noncytopathogenic (ncp) strain KS86-1 ncp after it was exposed to cp BVDV strain Nose and developed mucosal disease (MD). Molecular analysis revealed that an insertion of a cellular gene and a duplication of the viral RNA encoding the nucleocapsid protein C and part of N-pro had occurred in the C coding region of the Nose and KS86-1 cp genomes. The inserted cellular gene was closely related to the cINS sequence. Remarkably, the 5' upstream region from the insertion of KS86-1 cp had high sequence identity to that of Nose, but differed from that of KS86-1 ncp. In contrast, the region downstream from the insertion of KS86-1 cp showed high identity to KS86-1 ncp, but not to Nose. These data reveal that KS86-1 cp is a chimeric virus generated by homologous RNA recombination in a calf with MD.
  • Y Sakoda, N Ross-Smith, T Inoue, GJ Belsham
    JOURNAL OF VIROLOGY 75 (22) 10643 - 10650 0022-538X 2001/11 [Refereed][Not invited]
     
    Virulent and avirulent strains of swine vesicular disease virus (SVDV), a picornavirus, have been characterized previously. The major determinants for attenuation have been mapped to specific residues in the 1D-2A-coding region. The properties of the 2A proteases from the virulent and avirulent strains of SVDV have now been examined. Both proteases efficiently cleaved the 1D/2A junction in vitro and in vivo. However, the 2A protease of the avirulent strain of SVDV was much less effective than the virulent-virus 2A protease at inducing cleavage of translation initiation factor eIF4GI within transfected cells. Hence the virulent-virus 2A protease is much more effective at inhibiting cap-dependent protein synthesis. Furthermore, the virulent-virus 2A protease strongly stimulated the internal ribosome entry sites (IRESs) from coxsackievirus B4 and from SVDV, while the avirulent-virus 2A protease was significantly less active in these assays. Thus, the different properties of the 2A proteases from the virulent and avirulent strains of SVDV in regulating protein synthesis initiation reflect the distinct pathogenic properties of the viruses from which they are derived. A single amino acid substitution, adjacent to His21 of the catalytic triad, is sufficient to confer the characteristics of the virulent-strain 2A protease on the avirulent-strain protease. It is concluded that the efficiency of picornavirus protein synthesis, controlled directly by the IRES or indirectly by the 2A protease, can determine virus virulence.
  • M Nagai, T Ito, S Sugita, A Genno, K Takeuchi, T Ozawa, Y Sakoda, T Nishimori, K Takamura, H Akashi
    ARCHIVES OF VIROLOGY 146 (4) 685 - 696 0304-8608 2001 [Refereed][Not invited]
     
    Genomic properties of 62 field isolates of bovine viral diarrhea virus (BVDV) collected fi-om 1974 to 1999 in Japan were investigated. The 5' untranslated region (UTR) was amplified by reverse transcriptase polymerase chain reaction (RT-PCR) and the 244 to 247 base nucleotide sequences were determined. Serological properties were also characterized by the cross-neutralization test using antisera against the representative strain of the classified genotype. Using phylogenetic tree analysis, BVDV 1 was subdivided into two major clusters, BVDV-1a (29 isolates) and BVDV-1b (27 isolates). In group 1a, 3 differed from the other viruses, and were classified in a branch assigned as 1a'. However, 4 isolates (So CP/75, 190 CP, 190 NCP and KS86-1-NCP) could not be assigned to group 1a or 1b. In comparison with the published sequence data, KS86-1-NCP, 190 CP and 190 NCP were similar to the Southern Africa isolates that have recently been proposed as BVDV 1c. The 5' UTR sequence of So CP/75 was unique among those of BVDV 1, suggesting that the isolate should be classified into a new genotype. Only 2 out of 62 isolates collected in 1989 and 1990 were identified as BVDV 2. The results of the cross-neutralization test strongly supported these data, suggesting a close correlation between the 5' UTR sequence and the antigenicity of BVDV.
  • H Aoki, Y Sakoda, K Jukuroki, A Takada, H Kida, A Fukusho
    VETERINARY MICROBIOLOGY 68 (3-4) 197 - 207 0378-1135 1999/08 [Refereed][Not invited]
     
    The glycoprotein gB of pseudorabies virus (PrV) was expressed in various mammalian cells by a recombinant baculovirus carrying the PrV gB gene under the control of the CAG promoter. When the recombinant baculovirus was inoculated into the stable porcine kidney cell line CPK, expression of PrV gB was detected by immunofluorescent antibody analysis and a 155 kDa of protein, which has the same molecular mass as the native PrV gB, was detected by Western blotting. High levels of expression of PrV gB were observed in BHK-21, HmLu-1 and SK-K cell Lines. Furthermore, anti-PrV gB-specific antibodies against PrV gB protein were detected by the enzyme-linked immunosorbent assay in mice inoculated the recombinant baculovirus. The recombinant baculovirus containing the PrV glycoprotein gB gene under the CAG promoter could be a candidate for a pseudorabies vaccine. (C) 1999 Elsevier Science B.V. All rights reserved.
  • Yoshihiro Sakoda, Shin-Ichi Ozawa, Sudarat Damrongwatanapokin, Mitsuo Sato, Kiyoyasu Ishikawa, Akio Fukusho
    Veterinary Microbiology 65 (1) 75 - 86 0378-1135 1999/02/23 [Refereed][Not invited]
     
    The genetic variability of porcine and ruminant pestiviruses was studied by comparative nucleotide sequence analysis of 73 isolates (42 porcine and 31 ruminant), including 65 Japanese isolates (35 porcine and 30 ruminant). The 5'-untranslated region (UTR) amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) was determined by direct sequencing and phylogenetic analysis was performed from the nucleotide sequence data. Most porcine isolates were divided into two major subgroups, classical swine fever virus (CSFV) subgroup 1 (CSFV-1, represented by Brecia strain) and subgroup 2 (CSFV-2, represented by Alfort strain). However, the Japanese Kanagawa/74, Okinawa/86, Okinawa/86-2 and Thai CBR/93 strains were the most distinct variants and these were assigned to another new disparate subgroup, CSFV-3 (represented by p97 strain). Most ruminant isolates were classified as the bovine viral diarrhoea virus (BVDV) genotype-I (BVDV-I) and subdivided into two subgroups, BVDV-Ia (represented by the NADL strain) and Ib (represented by the Osloss strain). Two bovine isolates (MS-1 and SY-89) and a contaminating strain (V/FLL) from an ovine cell line were classified as BVDV genotype-II (BVDV-II) on genetic characteristics. These data suggested that the detection and phylogenetic analysis of 5'-UTRs are useful for the rapid characterization of field isolates.
  • Y Sakoda, M Hikawa, T Tamura, A Fukusho
    JOURNAL OF VIROLOGICAL METHODS 75 (1) 59 - 68 0166-0934 1998/11 [Refereed][Not invited]
     
    A stable porcine kidney cell line, CPK-NS, was established and maintained in serum-free culture. A cytopathic effect (CPE) was observed clearly in CPK-NS cells infected with some classical swine fever virus (CSFV) strains which did not show the exaltation of Newcastle disease virus (END) phenomenon. Chromosome condensation and DNA fragmentation, a marker for apoptosis, were detected in cells infected with END phenomenon-negative CSFV strains. By using the CPE induced by infection with an END phenomenon-negative CSFV strain in CPK-NS cells, assays of CSFV were established. The virus titer determined in CPK-NS cells shows a high correlation with the usual peroxidase-linked assay, dome disappearance method and END method. Furthermore, the antibody titer by neutralizing test with CPK-NS cells also correlated with that measured by the usual neutralizing peroxidase-linked assay and dome disappearance method. These stable CPK-NS cells have the great advantage that a clear CPE was caused by infection with END phenomenon-negative CSFV strains and bovine serum is not necessary for cell culture and virus assays. (C) 1998 Elsevier Science B.V. All rights reserved.
  • Y Sakoda, A Fukusho
    IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY-ANIMAL 34 (1) 53 - 57 1071-2690 1998/01 [Refereed][Not invited]
     
    A stable porcine kidney epithelial cell line, FS-L3, was established and maintained in Eagle's minimum essential medium containing 0.295% tryptose phosphate broth, 0.5% Bacto Peptone, and 10 mM N, N-Bis (2-hydroxyethyl)-2-aminoethanesulfonic acid without any serum. The mode of chromosomes is 37 to 38. The FS-L3 cells formed fluid-filled, multicellular, three-dimensional domes on a single monolayer. The number of domes increased markedly after further cultivation. The origin of this cell line was confirmed as porcine by hybridization using PRE-I, which can be detected as a specific sequence in the porcine genome. It was also found that FS-L3 cells were free from possible adventitious viruses and mycoplasmas.
  • E ONO, Y SAKODA, S TAHARAGUCHI, S WATANABE, N TONOMURA, H KIDA, Y SHIMIZU
    VIROLOGY 210 (1) 128 - 140 0042-6822 1995/06 [Refereed][Not invited]
     
    A chimeric gene encoding a fusion protein consisting of the DNA-binding domain of the immediate-early (IE) protein of pseudorabies virus (PRV) and a tail-truncated Vmw65 of herpes simplex virus I, lacking the transcription activation domain, was constructed. The chimeric gene product inhibited transcription from the PRV IE promoter in a transient expression assay. A HeLa cell line stably transformed with the chimeric gene showed remarkable resistance to PRV infection. In the transformed cells infected with PRV, transcription of the PRV IE gene was repressed, indicating that the resistance of the cells to PRV infection was due to interference with IE gene transcription by the fusion protein. (C) 1995 Academic Press, Inc.

MISC

  • 迫田 義博  医学のあゆみ  289-  (10)  766  -770  2024/06  
    ＜文献概要＞インフルエンザウイルスはヒトや動物に主に呼吸器感染症を引き起こすRNAウイルスである.ウイルスはA型からD型に分類され,ヒトに感染するのはA型,B型,およびC型ウイルスである.近年D型インフルエンザウイルスが発見され,ウシとブタからウイルスが分離されている.A型インフルエンザウイルスはヒト以外の哺乳動物や鳥に感染し,人獣共通感染症の病原体としても重要である.ウイルスタンパク質上のアミノ酸の点変異に加え,ウイルスの遺伝子の一部が動物由来のインフルエンザウイルスのそれに置き換わる,いわゆる遺伝子再集合により抗原性の異なる新しいウイルスが出現し,パンデミックを引き起こす.動物においては,鳥,ブタ,ウマ,イヌなどを宿主として感染を繰り返し,そのウイルスはヒトへの感染も報告されている.特に鳥インフルエンザウイルスのヒトへの感染は次のパンデミックの候補のひとつとして監視が強化されている.感染の中心であるA型およびB型インフルエンザウイルスの検出には抗原検出キットや遺伝子診断が用いられる.また,感染に対する治療には抗インフルエンザ薬,予防にはワクチンが有効である.
  • 迫田 義博  インフルエンザ  25-  (1)  35  -40  2024/03  
    H5N1亜型の高病原性鳥インフルエンザウイルスが1996年に中国で出現後,家禽における対策が不徹底な国々の影響を受けてウイルスはいまだに流行を繰り返している.ウイルスはさらにこれらの国から環境中に漏れ出し,渡り鳥に感染することで大陸を越えて世界各地に運ばれている.国際獣疫事務局は,発生に関する情報共有の促進や衛生対策の徹底を促すとともに,度重なる発生による貿易の支障を軽減させるために,国丸ごとではなく各国の地域単位で家禽製品の輸出入を認め,さらにワクチン接種への相互理解が必要であると提言している.日本はこれまでのワクチンに頼らない防疫対策の徹底を基本とすべきであるが,各国の鳥インフルエンザ対策の変化にも注視していく必要がある.(著者抄録)
  • 高病原性鳥インフルエンザウイルス感染の治療を目指したヒト用抗インフルエンザ薬のユーラシアワシミミズクへの投与試験
    島津 陽, 尾原 涼, 西村 享平, 三木 万梨子, 佐渡 晃浩, 境 秀文, 磯田 典和, 日尾野 隆大, 宍戸 貴雄, 齊藤 慶輔, 池中 良徳, 迫田 義博  日本野生動物医学会誌  28-  (Suppl.)  164  -165  2023/12
  • 迫田 義博  日本臨床内科医会会誌  38-  (3)  s92  -s92  2023/09
  • 組換えレポーターウイルスを用いたペスチウイルスの新しい感染価測定法の確立
    三村 優芽, Huynh Tan Loc, 小林 茉弥, 日尾野 隆大, 磯田 典和, 迫田 義博  日本獣医学会学術集会講演要旨集  166回-  128  -128  2023/09
  • 古典的ブタコレラマーカーワクチン用vGPE-由来キメラウイルスのレスキューと有効性(Rescue and efficacy of chimeric virus derived from vGPE- for classical swine fever marker vaccine)
    Huynh Tan Loc, Lim Hew Yik, 荻野 紗帆, 三村 優芽, 小林 茉弥, 金 琢洙, 日尾野 隆大, 磯田 典和, 迫田 義博  日本獣医学会学術集会講演要旨集  166回-  128  -128  2023/09
  • PRRS生ワクチンの豚熱生ワクチンの有効性に及ぼす影響の検討
    木田 萌子, 落合 絢子, 曵地 七星, 榊 基, 細田 裕子, 森崎 一葉, 一戸 夏美, 山崎 雅人, 長坂 孝雄, 大出水 幹男, 山下 麻依子, 迫田 義博, 山本 欣也  日本獣医学会学術集会講演要旨集  166回-  128  -128  2023/09
  • H13亜型鳥インフルエンザウイルスはオオセグロカモメの呼吸器上皮に分布するフコシル化α2,3シアル酸糖鎖を認識する
    原田 里桜, 日尾野 隆大, 小林 大樹, 伴 日向子, 五十嵐 学, 磯田 典和, 迫田 義博  日本獣医学会学術集会講演要旨集  166回-  130  -130  2023/09
  • 希少鳥類における高病原性鳥インフルエンザウイルス感受性評価のためのバイオマーカー探索
    鍋島 圭, 迫田 義博, 大沼 学  日本獣医学会学術集会講演要旨集  166回-  130  -130  2023/09
  • 牛ウイルス性下痢ウイルスの迅速な組換えウイルスの作出
    田村 友和, 荻野 紗帆, 日尾野 隆大, 鈴木 理滋, 鈴木 紗織, 磯田 典和, 迫田 義博, 福原 崇介  日本獣医学会学術集会講演要旨集  166回-  134  -134  2023/09
  • ザンビアにおけるブタインフルエンザの疫学調査
    播磨 勇人, 奥谷 公亮, 梶原 将大, 小川 寛人, Simulundu Edgar, Bwalya Eugene, 邱 永晋, 迫田 義博, 西藤 岳彦, Hang' ombe Bernard, 澤 洋文, Mweene Aaron, 高田 礼人  日本獣医学会学術集会講演要旨集  166回-  154  -154  2023/09
  • ネットワーク解析を用いた豚感染症リスクモデルの樹立とリスク管理法への応用
    吉田 恵実, 國永 尚稔, 子安 美紀, 森本 陽美記, 迫田 義博, 磯田 典和  日本獣医学会学術集会講演要旨集  166回-  219  -219  2023/09
  • 話題の感染症 鳥インフルエンザの現状と対策
    迫田 義博  Modern Media  69-  (8)  195  -200  2023/08
  • ネットワーク解析を用いた豚感染症リスク管理法の樹立
    吉田 恵実, 國永 尚稔, 子安 美紀, 森本 陽美記, 磯田 典和, 迫田 義博  獣医疫学雑誌  27-  (1)  23  -24  2023/07
  • ネットワーク解析を用いた岐阜県内養豚場における豚熱発生リスクの解析
    國永 尚稔, 吉田 恵実, 林 登, 磯田 典和, 迫田 義博  獣医疫学雑誌  27-  (1)  25  -26  2023/07
  • 2021-2022年冬季に国内で検出されたH5亜型高病原性鳥インフルエンザウイルスの性状と来シーズンの展望
    迫田 義博, 日尾野 隆大, 小林 大樹, Gulyaeva Marina, Shestopalov Alexander, 鍋島 圭, 本庄 比佐子, 横山 美沙子, 大沼 学, 磯田 典和  日本野生動物医学会誌  27-  (Suppl.)  161  -161  2023/03
  • 鳥類におけるバロキサビルマルボキシルの安全性の検討
    三木 万梨子, 尾原 涼, 西村 享平, 岡 良子, 宍戸 貴雄, 福島 民雄, 吉本 淳, 中山 翔太, 木村 亨史, 池中 良徳, 小笠原 浩平, 齊藤 慶輔, 日尾野 隆大, 磯田 典和, 迫田 義博  日本野生動物医学会誌  27-  (Suppl.)  176  -177  2023/03
  • 高病原性鳥インフルエンザウイルスに感染したオジロワシにおける,バロキサビルマルボキシルによる治療の試み
    齊藤 慶輔, 渡邊 有希子, 小笠原 浩平, 磯田 典和, 日尾野 隆大, 宍戸 貴雄, 西村 享平, 安達 光, 河野 晴子, 石井 千尋, 大沼 学, 迫田 義博  日本野生動物医学会誌  27-  (Suppl.)  182  -182  2023/03
  • 岐阜県における豚熱ワクチン免疫状況の解析と現状
    桑田 桂輔, 迫田 義博  日本豚病研究会報  (81)  8  -15  2023/02
  • 迫田 義博  臨床とウイルス  50-  (5)  250  -255  2022/12  
    H5N1亜型の高病原性鳥インフルエンザウイルスが1996年に中国で出現してから26年経過した.ニワトリやアヒル農家での対策が徹底されない国々の影響を受け,ウイルスは環境中に漏れ出し,渡り鳥に感染することで大陸をこえて運ばれる事態となった.特に2020～2021年の冬季からは3シーズン連続して日本でもウイルスが野鳥から検出され,家禽農家での発生も後を絶たない.さらにこのウイルスはヨーロッパ,アフリカ,北米にまで渡り鳥を介して拡散し,感染を拡大させている.また野鳥での感染が拡大し,接触したと考えられるキツネなどの哺乳動物からも感染が報告されている.ここ数年の感染状況を考えると,鳥インフルエンザウイルスの自然宿主である野生の水鳥に低病原性鳥インフルエンザウイルスだけでなく高病原性鳥インフルエンザウイルスも永続的に受け継がれていくことが懸念されている.One Healthの概念のもとに,野鳥におけるウイルス感染の監視を継続するとともに,家禽農場とヒトを含む哺乳動物へ感染の機会を遮断するために最大限努力が必要である.(著者抄録)
  • 北海道における野鳥および野生哺乳動物からのH5N1亜型高病原性鳥インフルエンザウイルスの検出事例について
    磯田 典和, 日尾野 隆大, 迫田 義博  病原微生物検出情報月報  43-  (11)  259  -260  2022/11
  • 2022年に北海道内の野鳥から分離された高病原性鳥インフルエンザウイルスの遺伝子解析と感染猛禽類に対する治療の試み
    磯田 典和, 日尾野 隆大, 渡邊 有希子, 曽田 公輔, 遠藤 真由美, 小笠原 浩平, 山口 剛士, 大沼 学, 齋藤 慶輔, 迫田 義博  日本獣医学会学術集会講演要旨集  165回-  [DV1A  -07]  2022/09
  • バロキサビルマルボキシルのニワトリへの4週間反復経口投与による安全性評価
    三木 万梨子, 尾原 涼, 西村 享平, 岡 良子, 宍戸 貴雄, 福島 民雄, 吉本 淳, 中山 翔太, 木村 享史, 池中 良徳, 日尾野 隆大, 磯田 典和, 迫田 義博  日本獣医学会学術集会講演要旨集  165回-  [DV1A  -08]  2022/09
  • キタキツネ及びタヌキからの高病原性鳥インフルエンザウイルスの分離
    日尾野 隆大, 磯田 典和, 小林 篤史, 小林 大樹, 鈴木 玲海, 佐竹 優樹, 松野 啓太, 佐鹿 万里子, 伴 日向子, 小林 茉弥, 高谷 文仁, 冨士田 裕子, 木村 享史, 迫田 義博  日本獣医学会学術集会講演要旨集  165回-  [DV1A  -09]  2022/09
  • 高病原性鳥インフルエンザウイルスに感染したキタキツネの病理学的解析とウイルス受容体の検出
    小林 大樹, 小林 篤史, 日尾野 隆大, 原田 里桜, 鈴木 玲海, 松野 啓太, 磯田 典和, 高谷 文仁, 冨士田 裕子, 木村 享史, 迫田 義博  日本獣医学会学術集会講演要旨集  165回-  [DV1A  -10]  2022/09
  • ヒトと微生物の共生:第2部 感染症の克服にむけて 日本国内における豚熱の現状と撲滅に向けた今後の課題
    迫田 義博  日本獣医学会学術集会講演要旨集  165回-  [O2P  -04]  2022/09
  • 豚コレラマーカーワクチン由来キメラウイルスのレスキュー(Rescue of a chimeric virus derived from classical swine fever vaccine strain for marker vaccine)
    Huynh Tan Loc, 荻野 紗帆, 三村 優芽, 金 琢洙, 日尾野 隆大, 磯田 典和, 迫田 義博  日本獣医学会学術集会講演要旨集  165回-  [DV3A  -10]  2022/09
  • 口蹄疫ウイルスおよび豚熱ウイルスRNAのIRES機能に関連する宿主因子の特性について
    井手 優太郎, Kitab Bouchra, 迫田 義博, 小原 恭子  日本獣医学会学術集会講演要旨集  165回-  [DV3P  -07]  2022/09
  • 2021～2022年シーズンの野鳥における高病原性鳥インフルエンザウイルスの流行の特徴と考察
    小笠原 浩平, 渡辺 有希子, 磯田 典和, 日尾野 隆大, 安達 光, 河野 晴子, 大沼 学, 迫田 義博, 齊藤 慶輔  北海道獣医師会雑誌  66-  (8)  302  -302  2022/08
  • 迫田 義博  臨床とウイルス  50-  (2)  44  -44  2022/05
  • 藤井祐至, 正谷達謄, 正谷達謄, 西山祥子, 岡島美鈴, 泉郁輝, 岡崎克則, 迫田義博, 高田礼人, 高田礼人, 小澤真, 杉山誠, 伊藤直人, 伊藤直人  日本ウイルス学会学術集会プログラム・予稿集(Web)  69th-  2022
  • 伊藤靖, 石垣宏仁, 仲山美沙子, NGUYEN Thanh Cong, 北川善紀, 安井文彦, 小原道法, 石井健, 新開大史, 迫田義博, 喜田宏  日本実験動物学会総会講演要旨集(Web)  69th-  2022
  • 梶原直樹, 山本直樹, 小原道法, 安井文彦, 迫田義博, 喜田宏, 芝崎太  日本薬学会年会要旨集(Web)  141年会-  28P01  -L006  2021/03
  • 迫田 義博  日本臨床  79-  (2)  176  -181  2021/02
  • 西森朝美, 安藤清彦, 迫田義博, 磯田典和, 廣瀬静香, 荻野紗帆  農研機構動物衛生研究部門成果情報(Web)  2021-  2021
  • 高瀬明, 高瀬明, 一宮智美, 岡松正敏, 木下貴明, 木下貴明, 小林大樹, 市居修, 市居修, 山本直樹, 山本直樹, 迫田義博, 迫田義博, 喜田宏, 川島博人, 山本一夫, 西原祥子, 西原祥子  日本ウイルス学会学術集会プログラム・予稿集(Web)  68th-  2021
  • 浮田真琴, 桑田桂輔, 田中英次, 磯田典和, 迫田義博, 蒔田浩平  獣医疫学雑誌  25-  (1)  2021
  • 小笠原浩平, 藤本佳万, 畑井仁, 磯田典和, 渡辺有希子, 大沼学, 小澤真, 迫田義博, 齊藤慶輔  北海道獣医師会雑誌  65-  (8)  2021
  • 桑田桂輔, 田中英次, 迫田義博, 蒔田浩平  日本産業動物獣医学会(中部)・日本小動物獣医学会(中部)・日本獣医公衆衛生学会(中部)  2021-  2021
  • 浮田真琴, 桑田桂輔, 田中英次, 磯田典和, 迫田義博, 蒔田浩平  日本獣医学会学術集会講演要旨集  164th (CD-ROM)-  [MO  -8]  2021
  • 荻野紗帆, 西森朝美, 廣瀬静香, 磯田典和, 磯田典和, 日尾野隆大, 安藤清彦, 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  164th (CD-ROM)-  2021
  • 小林大樹, 市居修, 日尾野隆大, 西原祥子, 高瀬明, 磯田典和, 磯田典和, 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  164th (CD-ROM)-  2021
  • 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  164th (CD-ROM)-  2021
  • 磯田典和, 磯田典和, 日尾野隆大, TWABELA Augustin T., BAZARRAGCHAA Enkhbold, KIEN Le Trung, LOC Huynh Tan, 小笠原浩平, 林裕貴, 渡辺有希子, 齊藤慶輔, 喜田宏, 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  164th (CD-ROM)-  [DVO  -70]  2021
  • 廣瀬静香, LOC Huynh Tan, 金琢珠, 磯田典和, 磯田典和, 日尾野隆大, 吉本圭一郎, 田中徹, 乾健二郎, 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  164th (CD-ROM)-  2021
  • 金琢洙, LOC Huynh Tan, 廣瀬静香, 日尾野隆大, 磯田典和, 磯田典和, 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  164th (CD-ROM)-  2021
  • LOC Huynh Tan, 廣瀬静香, 金琢洙, 田村友和, 福原崇介, 松浦善治, 日尾野隆大, 磯田典和, 磯田典和, 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  164th (CD-ROM)-  2021
  • 野村直樹, 新開大史, 松野啓太, 関屋俊輝, 関屋俊輝, 大野円実, 磯田典和, 迫田義博, 喜田宏, 喜田宏  日本獣医学会学術集会講演要旨集  164th (CD-ROM)-  [DVO  -74]  2021
  • LE Trung Kien, 磯田典和, 磯田典和, NGUYEN Thanh Lam, NGUYEN Thanh Lam, CHU Duc-Huy, TIEN Ngoc Tien, LE Thanh Tung, 日尾野隆大, 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  164th (CD-ROM)-  [MO  -13]  2021
  • 迫田義博, 迫田義博, 遠藤真由美, 伊藤貢, 日尾野隆大, 磯田典和, 磯田典和  日本獣医学会学術集会講演要旨集  164th (CD-ROM)-  2021
  • 迫田義博, 迫田義博, 迫田義博  日本臨床  2021
  • 迫田義博, 迫田義博, 遠藤真由美, 伊藤貢, 日尾野隆大, 磯田典和, 磯田典和  家畜衛生学雑誌  47-  (3)  2021
  • 高瀬明, 高瀬明, 一宮智美, 岡松正敏, 木下貴明, 木下貴明, 小林大樹, 市居修, 山本直樹, 山本直樹, 迫田義博, 迫田義博, 喜田宏, 川島博人, 山本一夫, 西原祥子, 西原祥子  日本糖質学会年会要旨集  40th-  2021
  • 迫田 義博  Pharma Medica  39-  (1)  37  -41  2021/01
  • 時空間解析を用いた日本における野生イノシシ群での豚熱感染拡大評価
    磯田 典和, 馬場 開陸, 伊藤 聡, 伊藤 貢, 迫田 義博, 蒔田 浩平  獣医疫学雑誌  24-  (2)  81  -82  2020/12
  • 野生イノシシにおけるCSF感染拡大様式評価のための地域2ヵ月期間有病率推定
    馬場 開陸, 磯田 典和, 伊藤 聡, 伊藤 貢, 迫田 義博, 蒔田 浩平  獣医疫学雑誌  24-  (2)  83  -84  2020/12
  • 迫田 義博  臨牀と研究  97-  (12)  1523  -1528  2020/12
  • CSFVのIRES発現細胞の作成と応用
    伊藤 伸将, Graham Belsham, 迫田 義博, 小原 恭子  日本獣医学会学術集会講演要旨集  163回-  227  -227  2020/10
  • 鳥インフルエンザウイルスの中間宿主としてのウズラおよびシチメンチョウにおけるシアル酸糖鎖分布の解析
    小林 大樹, 佐々木 乙, 日尾野 隆大, 岡松 正敏, 西原 祥子, 高瀬 明, 市居 修, 松野 啓太, 迫田 義博, 北海道大人獣共通感染症リサーチセンター/国際協働ユニット  日本獣医学会学術集会講演要旨集  163回-  230  -230  2020/10
  • マウスモデルにおけるインフルエンザウイルス感染に対するビタミンD代謝産物25(OH) D3の経口補給による効果
    林 裕貴, 岡松 正敏, 小笠原 帆南, 津川 尚子, 磯田 典和, 松野 啓太, 迫田 義博, 北海道大人獣共通感染症リサーチセンター/国際協働ユニット  日本獣医学会学術集会講演要旨集  163回-  231  -231  2020/10
  • 2016-2017年のベトナム南部での疫学的研究から明らかになった、鳥インフルエンザウイルスの新たなホットスポットの意義(The implication of a new hot spot of avian influenza based on epidemiological study in southern Vietnam in 2016-2017)
    Le Trung Kien, 磯田 典和, Nguyen Thanh Lam, Chu Duc-Huy, Tien Tien Ngoc, 松野 啓太, 岡松 正敏, 喜田 宏, 迫田 義博, 北海道大人獣共通感染症リサーチセンター/国際協働ユニット  日本獣医学会学術集会講演要旨集  163回-  232  -232  2020/10
  • コンゴ民主共和国で分離された新たなニューカッスル病ウイルスの性状(Characterization of novel Newcastle disease viruses isolated in the Democratic Republic of Congo)
    Twabela Augustin, Mpoyo Patrick, Masumu Justin, Zecchin Bianca, Monne Isabela, 岡松 正敏, 松野 啓太, 迫田 義博, 北海道大人獣共通感染症リサーチセンター/国際協働ユニット  日本獣医学会学術集会講演要旨集  163回-  233  -233  2020/10
  • ウイルス学的解析および疫学的解析を用いた北海道十勝地方における牛ウイルス性下痢ウイルスの伝播経路解明
    廣瀬 静香, 野津 昂亮, 松野 啓太, 岡松 正敏, 川本 恵子, 磯田 典和, 迫田 義博  日本獣医学会学術集会講演要旨集  163回-  236  -236  2020/10
  • 日本の岐阜県にてイノシシから採取した血中古典的ブタ熱ウイルス抗原と抗体に関する定量分析(Quantitative analysis of antigen and antibody of classical swine fever virus in wild boar sera collected in Gifu prefecture, Japan)
    Enkhbold Bazarragchaa, 金 琢洙, 哲翁 まどか, 磯田 典和, 松野 啓太, 迫田 義博, 北海道大人獣共通感染症リサーチセンター/国際協働ユニット  日本獣医学会学術集会講演要旨集  163回-  243  -243  2020/10
  • 野鳥糞便による全国鳥インフルエンザウイルスの疫学
    浅倉 真吾, 羽賀 淳, 岩田 律子, 中村 織江, 横山 美沙子, 五箇 公一, 岩中 麻里, 迫田 義博, 伊藤 啓史, 伊藤 壽啓, 小澤 真, 西藤 岳彦, 大沼 学  日本獣医学会学術集会講演要旨集  163回-  327  -327  2020/10
  • 豚熱(Classical Swine Fever:CSF)のすべて
    迫田 義博  北海道獣医師会雑誌  64-  (9)  285  -293  2020/09
  • ペスチウイルスの基礎
    迫田 義博  日本豚病研究会報  (76)  1  -7  2020/08
  • 迫田 義博  インフルエンザ  21-  (2)  98  -98  2020/06  [Not refereed][Not invited]
  • 豚コレラウイルス
    迫田 義博  ウイルス  69-  (2)  177  -186  2019/12  [Not refereed][Not invited]
     
    豚コレラウイルスはフラビウイルス科ペスチウイルス属のウイルスの1つである。このウイルスによるブタとイノシシの感染症である豚コレラは、口蹄疫やアフリカ豚コレラと同様に養豚において最も恐れられているブタの感染症である。2018年9月に国内としては26年ぶりに発生が報告され、56事例の感染が報告されている。感染拡大の要因は野生イノシシにおけるウイルスの蔓延であるが、野生動物における感染症のコントロールには時間がかかる。よって養豚場における衛生対策の徹底を継続することが必要である。本稿では、豚コレラウイルスを含むペスチウイルス属のウイルスに関する最新情報と日本における豚コレラの対策について紹介する。(著者抄録)
  • 迫田 義博  臨床と微生物  46-  (6)  703  -708  2019/11  [Not refereed][Not invited]
     
    豚コレラは最も恐れられているブタのウイルス感染症の1つである。2018年9月に国内としては26年ぶりに発生が報告された。野生イノシシにおけるウイルスの蔓延阻止が本病撲滅の鍵であるが、野生動物における感染症のコントロールには時間がかかるので、養豚場における衛生対策の徹底を継続することが必要である。(著者抄録)
  • インフルエンザ:古くて新しい話題 人獣共通感染症としてのインフルエンザ
    迫田 義博  日本小児感染症学会総会・学術集会プログラム・抄録集  51回-  107  -107  2019/10  [Not refereed][Not invited]
  • インフルエンザ:古くて新しい話題 人獣共通感染症としてのインフルエンザ
    迫田 義博  日本小児感染症学会総会・学術集会プログラム・抄録集  51回-  107  -107  2019/10  [Not refereed][Not invited]
  • 重症熱性血小板減少症候群ウイルスの核タンパク質Nと結合する宿主RNAの機能解明
    水間 奎太, 松野 啓太, 岡松 正敏, 高田 礼人, 迫田 義博  日本獣医学会学術集会講演要旨集  162回-  390  -390  2019/08  [Not refereed][Not invited]
  • ベトナムで初単離されたH7N7低病原性鳥インフルエンザウイルスの遺伝学的性状および抗原性の解析(Genetic and antigenic characterization of H7N7 low pathogenic avian influenza viruses firstly isolated in Vietnam)
    Le Trung Kien, Nguyen Thanh Lam, Chu Duc-Huy, Nguyen Tien Ngoc, Nguyen Long Van, Tien Tien Ngoc, 松野 啓太, 岡松 正敏, 喜田 宏, 迫田 義博  日本獣医学会学術集会講演要旨集  162回-  392  -392  2019/08  [Not refereed][Not invited]
  • 鶏の高病原性鳥インフルエンザウイルス感染に対する抗ウイルス薬の作用(Effect of antiviral drugs against highly pathogenic avian influenza virus infection in chickens)
    Augustin T. Twabela, 岡松 正敏, 松野 啓太, 迫田 義博  日本獣医学会学術集会講演要旨集  162回-  392  -392  2019/08  [Not refereed][Not invited]
  • 発光タグHiBiTをレポーターとして用いた遺伝子組換えウイルスによる簡便なペスチウイルス抗体測定法の確立
    哲翁 まどか, 松野 啓太, 田村 友和, 福原 崇介, 松浦 善治, 岡松 正敏, 迫田 義博  日本獣医学会学術集会講演要旨集  162回-  393  -393  2019/08  [Not refereed][Not invited]
  • 海外から持ち込まれた携帯品非加熱家きん畜産物から分離されたH7N3亜型高病原性鳥インフルエンザウイルスの性状解析
    柴田 明弘, 原田 理恵子, 岡松 正敏, 松野 啓太, 有田 知子, 鈴木 康司, 白倉 雅之, 小田切 孝人, 竹前 喜洋, 内田 裕子, 西藤 岳彦, 迫田 義博, 尾坂 優之  日本獣医学会学術集会講演要旨集  162回-  395  -395  2019/08  [Not refereed][Not invited]
  • マダニ中のフレボウイルスの遺伝子系統解析に基づく性状推定
    松野 啓太, 中尾 亮, 梶原 将大, 下田 宙, 海老原 秀喜, 高田 礼人, 前田 健, 岡松 正敏, 迫田 義博  日本獣医学会学術集会講演要旨集  162回-  400  -400  2019/08  [Not refereed][Not invited]
  • 迫田義博, 迫田義博, 迫田義博  臨床獣医  37-  (9)  33  -37  2019/08  [Not refereed][Not invited]
  • 【畜産現場のバイオセキュリティ〜最近の家畜衛生をめぐる情勢と農場における防疫体制〜】(第3章)我が国の農場での防疫対策 家畜伝染病と届出伝染病 豚コレラとバイオセキュリティ
    迫田 義博  臨床獣医  37-  (8)  105  -109  2019/07  [Not refereed][Not invited]
  • 迫田義博, 迫田義博, 迫田義博  臨床獣医  37-  (8)  105  -109  2019/07  [Not refereed][Not invited]
  • 日尾野隆大, 岡松正敏, 迫田義博  臨床とウイルス  47-  (1)  61  -68  2019/03  [Not refereed][Not invited]
  • 板倉友香里, 板倉友香里, 松野啓太, 松野啓太, 伊藤麻子, 藤本悠理, 田村友和, 亀山健一郎, 岡松正敏, NICOLAS Ruggli, NICOLAS Ruggli, 喜田宏, 喜田宏, 澤洋文, 澤洋文, 迫田義博, 迫田義博  日本ウイルス学会学術集会プログラム・予稿集(Web)  67th-  2019
  • 福原崇介, 田村友和, 鳥居志保, 小野慎子, 梶原健太郎, 森岡佑平, 山本拓弥, ファウジャー ユージー, 泉琢磨, 迫田義博, 松浦善治  日本ウイルス学会学術集会プログラム・予稿集(Web)  67th-  2019
  • 小山田孝嘉, 迫田義博, 迫田義博  日本小児臨床薬理学会雑誌  31-  (1)  101  -101  2019  [Not refereed][Not invited]
  • 迫田義博, 迫田義博, 迫田義博  臨床獣医  37-  (1)  40,18  -45,18  2019/01  [Not refereed][Not invited]
  • 迫田義博, 迫田義博  家畜衛生学雑誌  44-  (2)  61‐64  2018/12/14  [Not refereed][Not invited]
  • 迫田義博, SHATAR Munkhduuren, ENKHBOLD Bazarragchaa, 廣瀬和彦, 今泉好能, 松野啓太, 岡松正敏, TEMUUJIN Uyangaa, GANZORIG Basan, 梅村孝司  家畜衛生学雑誌  44-  (2)  92‐93  2018/12/14  [Not refereed][Not invited]
  • 迫田義博, 迫田義博, 迫田義博  鶏の研究  93-  (11)  12‐16  2018/11/01  [Not refereed][Not invited]
  • 迫田義博, 迫田義博, 迫田義博  鶏の研究  93-  (10)  12‐15  2018/10/01  [Not refereed][Not invited]
  • 磯田典和, 浅野明弘, 一條満, 大野浩, 佐藤一彦, 岡本浩一, 中尾茂, 加藤肇, 斉藤一真, 伊藤直樹, 臼井章, 高山裕章, 迫田義博  北海道獣医師会雑誌  62-  (8)  353  -353  2018/08/24  [Not refereed][Not invited]
  • 柴田明弘, 岡松正敏, 住吉理穂, 松野啓太, 松野啓太, WANG Zu‐Jyun, WANG Zu‐Jyun, 喜田宏, 喜田宏, 尾坂優之, 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  161st-  355  -355  2018/08/21  [Not refereed][Not invited]
  • 板倉友香里, 松野啓太, 岡松正敏, 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  161st-  345  -345  2018/08/21  [Not refereed][Not invited]
  • 菊谷祐斗, 岡松正敏, 西原祥子, 高瀬明, 松野啓太, 松野啓太, 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  161st-  355  -355  2018/08/21  [Not refereed][Not invited]
  • コンゴ民主共和国で2017年に単離されたH5N8高病原性鳥インフルエンザウイルスの性状解析(Characterization of H5N8 Highly Pathogenic Avian Influenza Viruses Isolated in DR Congo in 2017)
    Twabela Augustin, Tshilenge George, Nguyen Thanh-Lam, 松野 啓太, Monne Isabella, Zecchin Bianca, 岡松 正敏, 迫田 義博  日本獣医学会学術集会講演要旨集  161回-  356  -356  2018/08  [Not refereed][Not invited]
  • 2014-2017のベトナムにおけるH5高病原性鳥インフルエンザ発生の時空間・リスク解析(Spatiotemporal and risk analysis of H5 highly pathogenic avian influenza occurrence in Vietnam during 2014-2017)
    Nguyen Thanh-Lam, Stevenson Mark, Firestone Simon, Sims Les, Chu Huy, Nguyen Long, Nguyen Tien, 磯田 典和, 松野 啓太, 岡松 正敏, 喜田 宏, 迫田 義博  日本獣医学会学術集会講演要旨集  161回-  357  -357  2018/08  [Not refereed][Not invited]
  • 鳥インフルエンザウイルス検出におけるAlere i influenza A&Bの評価(Evaluation of Alere i influenza A&B for the detection of avian influenza virus)
    Enkhbold Bazarragchaa, 岡松 正敏, Ulaankhuu Ankhanbaatar, 松野 啓太, 喜田 宏, 新井 宏育, 迫田 義博  日本獣医学会学術集会講演要旨集  161回-  357  -357  2018/08  [Not refereed][Not invited]
  • 塩川舞, 大松勉, 片山幸枝, 水谷哲也, 迫田義博, 福所秋雄, 青木博史  日本獣医学会学術集会講演要旨集  161回-  362  -362  2018/08  [Not refereed][Not invited]
  • 迫田義博, 川本恵子  日本獣医学会学術集会講演要旨集  161回-  277  -277  2018/08  [Not refereed][Not invited]
  • 佐野豊, 伊藤直人, 伊藤直人, 西山祥子, 西山祥子, 岡田和真, 高橋龍樹, 岡崎克則, 高田礼人, 迫田義博, 小澤真, 正谷達謄, 杉山誠, 杉山誠  日本獣医学会学術集会講演要旨集  161回-  396  -396  2018/08  [Not refereed][Not invited]
  • 迫田義博, 迫田義博, 迫田義博  月刊呼吸器内科  33-  (2)  185‐190  -190  2018/02/28  [Not refereed][Not invited]
  • 岡松正敏, 迫田義博  小児科臨床  70-  2318‐2322  2017/12/20  [Not refereed][Not invited]
  • H5N1高病原性鳥インフルエンザウイルスのシアル酸非依存的な細胞侵入経路の解析
    梶原 直樹, 野村 奈美子, 宇梶 麻紗子, 貞任 大地, 山本 直樹, 小原 道法, 安井 文彦, 迫田 義博, 喜田 宏, 芝崎 太  生命科学系学会合同年次大会  2017年度-  [2P  -0957]  2017/12  [Not refereed][Not invited]
  • Takara Hajake, Dacquin Muhandwa Kasumba, Haruka Oda, Keita Matsuno, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroki Kato, Takashi Fujita  CYTOKINE  100-  27  -27  2017/12  [Not refereed][Not invited]
  • H5N1高病原性鳥インフルエンザウイルスのシアル酸非依存的な細胞侵入経路の解析
    梶原 直樹, 野村 奈美子, 宇梶 麻紗子, 貞任 大地, 山本 直樹, 小原 道法, 安井 文彦, 迫田 義博, 喜田 宏, 芝崎 太  生命科学系学会合同年次大会  2017年度-  [2P  -0957]  2017/12  [Not refereed][Not invited]
  • 【グローバル化・温暖化と感染症対策】 新興・再興感染症 H7N9鳥インフルエンザ
    岡松 正敏, 迫田 義博  小児科臨床  70-  (増刊)  2318  -2322  2017/12  [Not refereed][Not invited]
  • 迫田義博, 迫田義博, 喜田宏, 喜田宏  感染症  47-  (6)  189‐199  -199  2017/11/20  [Not refereed][Not invited]
     
    H5N1亜型の高病原性鳥インフルエンザウイルスが1996年に中国で出現し、1997年には鳥からヒトへの感染が初めて報告され、世界的な関心が高まった。それから20年経過したが、ニワトリからアヒル農場での対策が不徹底な諸外国の影響を受け、ウイルスはいまだにこれらの国々の農場で流行を繰り返している。ウイルスは環境中に漏れ出し、渡り鳥に感染することで大陸を越えて運ばれる事態となり、日本もその被害国の1つである。H5ウイルスはヒトからヒトへの感染は報告されていないが、鳥からヒトに直接感染し、現在も死亡者が報告されている。初発生以降、中国や東南アジアでニワトリやアヒルに対しワクチンが使用されているため、ワクチン接種群での見えない感染(不顕性感染)が続き、同時に抗原変異株が次々と出現した。H5亜型高病原性鳥インフルエンザウイルスの進化は、20年間途切れることなく、ワクチン接種下でウイルスがニワトリやアヒルの間で受け継がれたことが最大の要因である。このウイルスの抗原性と遺伝子の進化(変異)は、すべての鳥インフルエンザ対策をさらに難しくさせている。このH5亜型に加え、H7亜型高病原性鳥インフルエンザウイルスが中国で新たに出現し、ヒトへの感染も報告されている。ニワトリやアヒル、すなわち家禽における鳥インフルエンザ対策を徹底し、環境中に漏れ出るウイルスをなくすこと以外、動物と人の健康を守る手段はない。(著者抄録)
  • 市川正孝, 三田村敬子, 安倍隆, 岡田隆滋, 岡田隆文, 後藤泰浩, 迫田義博, 佐藤勇, 時田章史, 豊田茂, 中尾歩, 藤枝俊之, 松井忠孝, 松永貞一, 山崎雅彦, QIAN Yuan, MAI Le, 齋藤玲子  医学と薬学  74-  (10)  1299‐1310  -1310  2017/09/27  [Not refereed][Not invited]
     
    新しいインフルエンザ抗原迅速診断キット「クイックナビ-Flu2」(デンカ生研株式会社)の性能評価を行った。本品は着色ラテックス粒子を用いたイムノクロマト法を原理とした試薬であり、最終陰性判定時間が5分と従来品に比べ短縮され、かつラインが見やすくなったことが特徴である。基礎的検討では主な呼吸器感染症の原因ウイルスおよび細菌との交差反応は認められず、ヒトおよび動物由来のA型インフルエンザウイルスとの反応性も確認した。臨床性能試験(鼻腔拭い液n=248、鼻腔吸引液n=518、咽頭拭い液n=685)では、ウイルス分離培養を基準とした本品の感度はA型:94.8〜97.0%、B型:90.8〜97.8%、特異度はA型:98.4〜99.0%、B型:94.7〜98.3%で、全体一致率はいずれの検体種においても90%以上と良好な結果であった。また陽性となった症例の約90%が2分以内に判定が可能であり、5分という最終陰性判定時間を考慮するとインフルエンザ流行期の診療効率の改善に有用な診断キットであると考えられた。(著者抄録)
  • 増田恒幸, 黒田萌黄, 岩尾健, 池本千恵美, 小谷道子, 増田康充, 亀山健一郎, 迫田義博  日本獣医師会雑誌  70-  (9)  575‐579  -579  2017/09/20  [Not refereed][Not invited]
     
    鳥取県では2012年以降、牛ウイルス性下痢ウイルス(BVDV)感染症清浄化対策を実施しており、多数の持続感染(PI)牛を摘発している。2016年1月から10月にかけてBVDV-1のPI牛が3農場で6頭摘発された。疫学調査の結果、6頭の母牛はほぼ同じ期間に県外の同一育成牧場へ預託されていたことが判明した。6頭中5頭から分離されたBVDVのE2遺伝子領域の分子系統樹解析では、5株はすべてBVDV-1cに分類され、株間の相同性は99.6〜99.9%であった。このことから、PI牛の母牛は預託期間中にBVDV-1cに感染し、帰還後にPI牛を産出したと推察された。県外預託牛由来PI牛によるBVDVの侵入パターンが示されたため、BVDV感染症清浄化には地域単位の対策だけでなく、国主導による全国的な対策が必要と考えられた。(著者抄録)
  • 増田 恒幸, 黒田 萌黄, 岩尾 健, 池本 千恵美, 小谷 道子, 増田 康充, 亀山 健一郎, 迫田 義博  日本獣医師会雑誌  70-  (9)  575  -579  2017/09  [Not refereed][Not invited]
     
    鳥取県では2012年以降、牛ウイルス性下痢ウイルス(BVDV)感染症清浄化対策を実施しており、多数の持続感染(PI)牛を摘発している。2016年1月から10月にかけてBVDV-1のPI牛が3農場で6頭摘発された。疫学調査の結果、6頭の母牛はほぼ同じ期間に県外の同一育成牧場へ預託されていたことが判明した。6頭中5頭から分離されたBVDVのE2遺伝子領域の分子系統樹解析では、5株はすべてBVDV-1cに分類され、株間の相同性は99.6〜99.9%であった。このことから、PI牛の母牛は預託期間中にBVDV-1cに感染し、帰還後にPI牛を産出したと推察された。県外預託牛由来PI牛によるBVDVの侵入パターンが示されたため、BVDV感染症清浄化には地域単位の対策だけでなく、国主導による全国的な対策が必要と考えられた。(著者抄録)
  • 判定時間を短縮した新しいインフルエンザ迅速診断キット「クイックナビ-Flu2」の評価
    市川 正孝, 三田村 敬子, 安倍 隆, 岡田 隆滋, 岡田 隆文, 後藤 泰浩, 迫田 義博, 佐藤 勇, 時田 章史, 豊田 茂, 中尾 歩, 藤枝 俊之, 松井 忠孝, 松永 貞一, 山崎 雅彦, Yuan Qian, Le Mai, 齋藤 玲子  医学と薬学  74-  (10)  1299  -1310  2017/09  [Not refereed][Not invited]
     
    新しいインフルエンザ抗原迅速診断キット「クイックナビ-Flu2」(デンカ生研株式会社)の性能評価を行った。本品は着色ラテックス粒子を用いたイムノクロマト法を原理とした試薬であり、最終陰性判定時間が5分と従来品に比べ短縮され、かつラインが見やすくなったことが特徴である。基礎的検討では主な呼吸器感染症の原因ウイルスおよび細菌との交差反応は認められず、ヒトおよび動物由来のA型インフルエンザウイルスとの反応性も確認した。臨床性能試験(鼻腔拭い液n=248、鼻腔吸引液n=518、咽頭拭い液n=685)では、ウイルス分離培養を基準とした本品の感度はA型:94.8〜97.0%、B型:90.8〜97.8%、特異度はA型:98.4〜99.0%、B型:94.7〜98.3%で、全体一致率はいずれの検体種においても90%以上と良好な結果であった。また陽性となった症例の約90%が2分以内に判定が可能であり、5分という最終陰性判定時間を考慮するとインフルエンザ流行期の診療効率の改善に有用な診断キットであると考えられた。(著者抄録)
  • 小佐々隆志, 鳥居志保, 長坂孝雄, 山下麻依子, 落合絢子, 関口秀人, 齋藤明人, 塩川舞, 青木博史, 岡松正敏, 迫田義博  日本獣医学会学術集会講演要旨集  160th-  398  -398  2017/08/30  [Not refereed][Not invited]
  • 岡松正敏, 日尾野隆大, 菊谷祐斗, 鈴木瑞穂, NGUYEN Thanh‐Lam, 松野啓太, 松野啓太, 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  160th-  382  -382  2017/08/30  [Not refereed][Not invited]
  • 藤野高志, 市川陽子, 三田村敬子, 市川正孝, 吉原成哲, 許斐康司, 安倍隆, 清水英明, 山崎雅彦, 八角有紀, 迫田義博  医学と薬学  74-  (9)  1129‐1135  -1135  2017/08/27  [Not refereed][Not invited]
     
    われわれは、着色セルロース微粒子をコンジュゲートに使用し視認性を高め、判定までの時間を5分に短縮した「ファインビジョンInfluenza」の臨床検討を2013/2014シーズンに行い、報告した。今回は異なるシーズンである2016/2017シーズンで同様の検討を実施し、流行シーズン間での発熱時間に対する検出率の比較検討を行った。2016年12月から2017年3月まで、国内6ヶ所の医療機関を受診しインフルエンザウイルス感染が疑われた患者118名を対象とし、対照品として「クイックナビ-Flu」を使用した。ウイルス分離培養により69検体でA型を検出し、A型69株の亜型はすべてAH3であった。11検体でB型を検出し、Victoria系統9検体、Yamagata系統2検体であった。ウイルス分離培養を基準とすると、ファインビジョンの感度はA型98.6%(68/69)、B型100%(11/11)、対照品クイックナビの感度はA型97.1%(67/69)、B型100%(11/11)であり、特異度はともに100%(38/38)であった。発熱から採取までの経過時間を3、6、9、12、24、72時間後までに区切ると、A型においてファインビジョンは12時間までの累積感度は100%(28/28)、〜24時間までの累積で98.3%(57/58)、〜72時間までのトータルで98.6%(68/69)であった。B型ではすべての区で100%であった。既報告の2013/2014シーズン同様に2016/2017シーズン患者においても感染初期に相当する早期発熱時間から良好な検出率を示した また、2016年に発生した鳥インフルエンザウイルスH5N6亜型との反応性を検討し、ファインビジョンにおいて同株ならびにH5N1、H5N8亜型ウイルスとの反応を確認した。ファインビジョンは、流行シーズンやウイルス株によらずインフルエンザウイルスに対する良好な検出率を持つことが示され、臨床的有用性が改めて示された。(著者抄録)
  • 小笠原浩平, 渡辺有希子, NGUYEN Lam Thanh, 岡松正敏, 鈴木瑞穂, 迫田義博, 齊藤慶輔  北海道獣医師会雑誌  61-  (8)  359  -359  2017/08/10  [Not refereed][Not invited]
  • 迫田義博  北海道獣医師会雑誌  61-  (8)  364  2017/08/10  [Not refereed][Not invited]
  • 2016-2017年冬季に北日本で野鳥及び飼育鳥から分離されたH5N6高病原性鳥インフルエンザウイルスの性状解析
    岡松 正敏, 日尾野 隆大, 菊谷 祐斗, 鈴木 瑞穂, Nguyen Thanh-Lam, 松野 啓太, 迫田 義博  日本獣医学会学術集会講演要旨集  160回-  382  -382  2017/08  [Not refereed][Not invited]
  • 2.3.4.4高病原性鳥インフルエンザウイルスに対する新規モノクローナル抗体を用いた免疫クロマトグラフィーキットによるH5ヘマグルチニンの迅速かつ広範囲検出(Rapid and broad detection of H5 hemagglutinin by an immunochromatographic kit using novel monoclonal antibody against a 2.3.4.4 highly pathogenic avian influenza virus)
    Nguyen Thanh-Lam, 中石 和成, 本島 桂子, 大河原 彩子, 日尾野 隆大, 松野 啓太, 岡松 正敏, 高田 礼人, 喜田 宏, 迫田 義博  日本獣医学会学術集会講演要旨集  160回-  384  -384  2017/08  [Not refereed][Not invited]
  • H13鳥インフルエンザウイルスの遺伝子と抗原の性状(Genetic and antigenic characterization of H13 avian influenza viruses)
    Wang Zu Jyun, 菊谷 祐斗, Nguyen Thanh-Lam, 松野 啓太, 岡松 正敏, 迫田 義博  日本獣医学会学術集会講演要旨集  160回-  385  -385  2017/08  [Not refereed][Not invited]
  • 国内の牛ウイルス性下痢・粘膜病(BVD-MD)ワクチン接種牛におけるHoBi-likeウイルス(牛ウイルス性下痢ウイルス(BVDV)3型)に対する交差反応性
    小佐々 隆志, 鳥居 志保, 長坂 孝雄, 山下 麻依子, 落合 絢子, 関口 秀人, 齋藤 明人, 塩川 舞, 青木 博史, 岡松 正敏, 迫田 義博  日本獣医学会学術集会講演要旨集  160回-  398  -398  2017/08  [Not refereed][Not invited]
  • Rapid and broad detection of H5 hemagglutinin by an immunochromatographic kit using novel monoclonal antibody against a 2.3.4.4 highly pathogenic avian influenza virus(和訳中)
    Nguyen Thanh-Lam, 中石 和成, 本島 桂子, 大河原 彩子, 日尾野 隆大, 松野 啓太, 岡松 正敏, 高田 礼人, 喜田 宏, 迫田 義博  日本獣医学会学術集会講演要旨集  160回-  384  -384  2017/08  [Not refereed][Not invited]
  • Genetic and antigenic characterization of H13 avian influenza viruses(和訳中)
    Wang Zu Jyun, 菊谷 祐斗, Nguyen Thanh-Lam, 松野 啓太, 岡松 正敏, 迫田 義博  日本獣医学会学術集会講演要旨集  160回-  385  -385  2017/08  [Not refereed][Not invited]
  • 簡易キット陰性と判定された死亡野鳥からの高病原性鳥インフルエンザウイルス伝播の可能性
    小笠原 浩平, 渡辺 有希子, Nguyen Lam Thanh, 岡松 正敏, 鈴木 瑞穂, 迫田 義博, 齊藤 慶輔  北海道獣医師会雑誌  61-  (8)  359  -359  2017/08  [Not refereed][Not invited]
  • 高病原性鳥インフルエンザの最新情報 家きん防疫と野鳥監視の現場から 高病原性鳥インフルエンザ最新情報について
    迫田 義博  北海道獣医師会雑誌  61-  (8)  364  -364  2017/08  [Not refereed][Not invited]
  • インフルエンザウイルス抗原迅速検出キット「ファインビジョンInfluenza」の流行シーズン間の検出率および新たに報告された鳥インフルエンザウイルスに対する反応性に関する検討
    藤野 高志, 市川 陽子, 三田村 敬子, 市川 正孝, 吉原 成哲, 許斐 康司, 安倍 隆, 清水 英明, 山崎 雅彦, 八角 有紀, 迫田 義博  医学と薬学  74-  (9)  1129  -1135  2017/08  [Not refereed][Not invited]
     
    われわれは、着色セルロース微粒子をコンジュゲートに使用し視認性を高め、判定までの時間を5分に短縮した「ファインビジョンInfluenza」の臨床検討を2013/2014シーズンに行い、報告した。今回は異なるシーズンである2016/2017シーズンで同様の検討を実施し、流行シーズン間での発熱時間に対する検出率の比較検討を行った。2016年12月から2017年3月まで、国内6ヶ所の医療機関を受診しインフルエンザウイルス感染が疑われた患者118名を対象とし、対照品として「クイックナビ-Flu」を使用した。ウイルス分離培養により69検体でA型を検出し、A型69株の亜型はすべてAH3であった。11検体でB型を検出し、Victoria系統9検体、Yamagata系統2検体であった。ウイルス分離培養を基準とすると、ファインビジョンの感度はA型98.6%(68/69)、B型100%(11/11)、対照品クイックナビの感度はA型97.1%(67/69)、B型100%(11/11)であり、特異度はともに100%(38/38)であった。発熱から採取までの経過時間を3、6、9、12、24、72時間後までに区切ると、A型においてファインビジョンは12時間までの累積感度は100%(28/28)、〜24時間までの累積で98.3%(57/58)、〜72時間までのトータルで98.6%(68/69)であった。B型ではすべての区で100%であった。既報告の2013/2014シーズン同様に2016/2017シーズン患者においても感染初期に相当する早期発熱時間から良好な検出率を示した また、2016年に発生した鳥インフルエンザウイルスH5N6亜型との反応性を検討し、ファインビジョンにおいて同株ならびにH5N1、H5N8亜型ウイルスとの反応を確認した。ファインビジョンは、流行シーズンやウイルス株によらずインフルエンザウイルスに対する良好な検出率を持つことが示され、臨床的有用性が改めて示された。(著者抄録)
  • 豚丹毒生ワクチン針刺し後に右膝慢性非特異性滑膜炎をきたした1例
    渡辺 尭仁, 小野寺 智洋, 新井 隆太, 亀田 敏明, 薮内 康史, 近藤 英司, 岩崎 倫政, 迫田 義博  北海道整形災害外科学会雑誌  59-  (1)  166  -167  2017/08  [Not refereed][Not invited]
  • 高病原性鳥インフルエンザの最新情報 家きん防疫と野鳥監視の現場から 高病原性鳥インフルエンザ最新情報について
    迫田 義博  北海道獣医師会雑誌  61-  (8)  364  -364  2017/08  [Not refereed][Not invited]
  • 迫田義博, 迫田義博, 小山田孝嘉, 小山田孝嘉  臨床とウイルス  45-  (2)  S72  -S72  2017/04/21  [Not refereed][Not invited]
  • 迫田義博, 迫田義博, 迫田義博  最新医学  72-  (4)  546‐553  -553  2017/04/10  [Not refereed][Not invited]
     
    H5またはH7亜型のA型インフルエンザウイルスのうち,ニワトリに対して致死的な病原性を示すものを高病原性鳥インフルエンザウイルスと呼ぶ.常在国である中国や東南アジアでは,このウイルスが鳥からヒトに感染し,死亡例も多数報告されている.しかし,このウイルスはヒトからヒトへの感染が成立しないので,飼養されているニワトリやアヒルへの対策を徹底すれば,ヒトへの感染リスクはなくなる.つまり,家禽における感染源対策の徹底がOne Health実現の要である.(著者抄録)
  • 熊谷卓司, 中山哲夫, 奥野良信, 森川佐依子, 加瀬哲男, 纐纈律子, 吉井洋紀, 本條健太, 迫田義博, 喜田宏, 庵原俊昭  日本小児感染症学会総会・学術集会プログラム・抄録集  49th-  136  2017  [Not refereed][Not invited]
  • 豚丹毒生ワクチン針刺し後に右膝慢性滑膜炎をきたした1例
    渡辺 尭仁, 小野寺 智洋, 新井 隆太, 亀田 敏明, 薮内 康史, 近藤 英司, 岩崎 倫政, 迫田 義博  北海道医学雑誌  91-  (2)  88  -89  2016/11  [Not refereed][Not invited]
  • 豚丹毒生ワクチン針刺し後に右膝慢性滑膜炎をきたした1例
    渡辺 尭仁, 小野寺 智洋, 新井 隆太, 亀田 敏明, 薮内 康史, 近藤 英司, 岩崎 倫政, 迫田 義博  北海道医学雑誌  91-  (2)  88  -89  2016/11  [Not refereed][Not invited]
  • 渡辺尭仁, 小野寺智洋, 新井隆太, 亀田敏明, 薮内康史, 近藤英司, 岩崎倫政, 迫田義博  北海道医学雑誌  91-  (2)  88‐89  2016/11/01  [Not refereed][Not invited]
  • 塩川舞, 内山汐里, 長井誠, 長井誠, 片山幸枝, 水谷哲也, 迫田義博, 福所秋雄, 青木博史  日本獣医学会学術集会講演要旨集  159th-  388  -388  2016/08/30  [Not refereed][Not invited]
  • 迫田義博, 迫田義博, BAZARRAGCHAA Enkhbold, MUNKHDUUREN Shatar, 若森史穂, 日尾野隆大, 松野啓太, 松野啓太, 岡松正敏, BATCHULUUN Damdinjav, 梅村孝司  日本獣医学会学術集会講演要旨集  159th-  388  -388  2016/08/30  [Not refereed][Not invited]
  • 堀本泰介, 日尾野隆大, 目堅博久, 小田切友葉, 雷志皓, 遠藤麻衣子, 上間亜希子, 小林知也, CHAMBERS James, 内田和幸, 西原真杉, 乗峰潤三, 猪島康雄, 彦野弘一, 村上賢二, 佐藤礼一郎, 村上裕信, 阪口雅弘, 安藤貴朗, 乙丸孝之介, 小澤真, 石井一功, 迫田義博, 村上晋  日本獣医学会学術集会講演要旨集  159th-  386  -386  2016/08/30  [Not refereed][Not invited]
  • 高橋望, 西根薫, 塩川舞, 迫田義博, 福所秋雄, 青木博史  日本獣医学会学術集会講演要旨集  159th-  374  -374  2016/08/30  [Not refereed][Not invited]
  • 柴田明弘, 日尾野隆大, 福原久江, 住吉理穂, 大河原彩子, 松野啓太, 松野啓太, 岡松正敏, 迫田義博, 迫田義博, 尾坂優之  日本獣医学会学術集会講演要旨集  159th-  382  -382  2016/08/30  [Not refereed][Not invited]
  • ワクチン接種後の鶏におけるH5鳥インフルエンザウイルスの抗原多様性の選択(Selection of antigenic variants of H5 avian influenza viruses in vaccinated chickens)
    Nguyen Thanh-Lam, 西 達也, 七戸 新太郎, Chu Duc-Huy, 日尾野 隆大, 松野 啓太, 岡松 正敏, 喜田 宏, 迫田 義博  日本獣医学会学術集会講演要旨集  159回-  371  -371  2016/08  [Not refereed][Not invited]
  • 田中良子, 信本聖子, 立花智, 迫田義博, 西英機  臨床獣医  34-  (6)  25‐28  -28  2016/06/01  [Not refereed][Not invited]
     
    ウシウイルス性下痢ウイルス(BVDV)の主な感染源はBVDB持続感染牛(PI牛)であり、PI牛の摘発、淘汰は清浄化のため重要である。BVDV抗原検出ELISAは従来の検査法に比べ簡易で迅速に行えることから、ELISAと従来法の遺伝子検査及びウイルス分離検査との結果を比較した。北海道十勝管内で採取された野外血清材料で、RT-PCRとウイルス分離を行った。抗原検査としてMDBK細胞、MDBK-SY細胞、またはBFM細胞のいずれかに被験血清を接種し、細胞を固定後、免疫染色法により抗原を検出した。また、被験血清のBVDV1型及び2型に対する中和抗体を、MDBK-SY細胞を用いて血清希釈法により測定した。ELISAとRT-PCRの一致率は0.77、ELISAとウイルス分離は0.74で、ELSIAとRT-PCRの間では採材月齢が5ヵ月齢以上になると完全に一致した。また、ELISA陰性でRT-PCR陽性の8頭全てと、ELISA陽性でウイルス分離陰性の8検体の内6検体が中和抗体を保有していた。ELISAはRTーPCRより劣るが、ウイルス分離よりは中和抗体の影響を受けにくいと考えられた。
  • 熊谷卓司, 中山哲夫, 奥野良信, 加瀬哲男, 森川佐依子, 迫田義博, 迫田義博, 喜田宏, 管秀, 庵原俊昭  日本ワクチン学会学術集会プログラム・抄録集  20th-  83  2016  [Not refereed][Not invited]
  • 渡辺尭仁, 小野寺智洋, 新井隆太, 迫田義博, 亀田敏明, 薮内康史, 近藤英司, 岩崎倫政  北海道整形災害外科学会  131st-  103  2016  [Not refereed][Not invited]
  • 田村友和, RUGGLI Nicolas, 松野啓太, 松野啓太, 岡松正敏, 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  158th-  346  -346  2015/08/30  [Not refereed][Not invited]
  • 小笠原浩平, 岡松正敏, 日尾野隆大, 七戸新太郎, 栗林沙弥, 市川貴也, 西達也, CHU Duc‐Huy, 鈴木瑞穂, 遠藤真由美, 田中和之, 谷川力, 喜田宏, 喜田宏, 喜田宏, 迫田義博, 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  158th-  333  -333  2015/08/30  [Not refereed][Not invited]
  • 中務陽裕, 来馬浩二, 鈴木瑞穂, 日尾野隆大, 小山田孝嘉, 岡松正敏, 迫田義博, 迫田義博  日本獣医学会学術集会講演要旨集  158th-  329  -329  2015/08/30  [Not refereed][Not invited]
  • 日尾野隆大, 岡松正敏, 五十嵐学, 五十嵐学, MCBRIDE Ryan, DE VIRES Robert, PAULSON James, 松野啓太, 松野啓太, 迫田義博, 迫田義博, 喜田宏, 喜田宏, 喜田宏  日本獣医学会学術集会講演要旨集  158th-  332  2015/08/30  [Not refereed][Not invited]
  • 松野啓太, 松野啓太, 下田宙, 鳥居志保, 邱永晋, 中尾亮, 梶原将大, 岡松正敏, 迫田義博, 迫田義博, 奥村敦, 奥村敦, 高田礼人, 高田礼人, 前田健, 海老原秀喜  日本獣医学会学術集会講演要旨集  158th-  344  -344  2015/08/30  [Not refereed][Not invited]
  • 2014年のベトナムにおける介入有りまたは介入なしの生鳥市場にて単離された鳥インフルエンザウイルスの性状解析(Characterization of avian influenza viruses isolated in live bird markets with and without intervention in Vietnam in 2014)
    Chu Duc-Huy, 岡松 正敏, 松野 啓太, 日尾野 隆大, 小笠原 浩平, 鈴木 瑞穂, Nguyen Thanh Lam, 喜田 宏, 迫田 義博  日本獣医学会学術集会講演要旨集  158回-  329  -329  2015/08  [Not refereed][Not invited]
  • 渡り鳥から検出された新型ロタウイルスAの遺伝学的解析
    藤井 祐至, 岡寺 康太, 三竹 博道, 伊藤 直人, 岡田 和真, 中川 賢人, 岡崎 克則, 迫田 義博, 高田 礼人, 小澤 真, 正谷 達謄, 杉山 誠  日本獣医学会学術集会講演要旨集  158回-  371  -371  2015/08  [Not refereed][Not invited]
  • 迫田 義博  生体の科学  66-  (4)  301  -304  2015/07  [Not refereed][Not invited]
  • 日尾野隆大, 岡松正敏, 五十嵐学, 五十嵐学, MCBRIDE Ryan, DE VIRES Robert P, PAULSON James C, 迫田義博, 迫田義博, 喜田宏, 喜田宏  日本糖質学会年会要旨集  34th-  173  2015/07/01  [Not refereed][Not invited]
  • インフルエンザのグローバルサーベイランス
    迫田 義博  感染・炎症・免疫  45-  (2)  116  -123  2015/07  [Not refereed][Not invited]
  • 全粒子ワクチンは複数のクレードのH5N1高病原性鳥インフルエンザウイルスに対する記憶免疫反応を誘導する
    仲山 美沙子, 七戸 新太郎, 伊藤 靖, 石垣 宏仁, 北野 光崇, 有方 雅彦, Pham Van Loi, 石田 英晃, 北川 直子, 小笠原 一誠, 土屋 英明, 中村 紳一朗, 岡松 正敏, 迫田 義博, 市川 貴也, 喜田 宏, Le Quynh Mai, 伊藤 睦美, 河岡 義裕  滋賀医学  37-  146  -146  2015/03  [Not refereed][Not invited]
  • 田村友和, 峯淳貴, 鳥居志保, 藤本悠理, 岡松正敏, 迫田義博  日本獣医師会獣医学術学会年次大会講演要旨集  2014-  2015
  • 南部谷俊介, 前川達洋, 秀島翔, 比能洋, 西村紳一郎, 迫田義博, 黒岩繁樹, 中西卓也, 逢坂哲彌, 逢坂哲彌  Chemical Sensors  31-  (Supplement A)  2015
  • Masatoshi OKAMATSU, Yoshihiro SAKODA, Hiroshi KIDA  化学療法の領域  30-  (12)  25  -32  2014/12  [Not refereed][Not invited]
  • 岡松正敏, 迫田義博, 喜田宏  化学療法の領域  30-  (12)  2173  -2180  2014/11/25  [Not refereed][Not invited]
  • 田村友和, RUGGLI Nicolas, LINGER Matthias, 長島尚史, 峯淳貴, 岡松正敏, HOFMANN Martin A, SUMMERFIELD Artur, 喜田宏, 迫田義博  日本ウイルス学会学術集会プログラム・抄録集  62nd-  250  2014/10/31  [Not refereed][Not invited]
  • 柳田里澄, 岡松正敏, 日尾野隆大, 迫田義博, 喜田宏  日本ウイルス学会学術集会プログラム・抄録集  62nd-  155  2014/10/31  [Not refereed][Not invited]
  • 岡松正敏, 日尾野隆大, 五十嵐学, DE VRIES Robert, 西原祥子, 高瀬明, PAULSON James C, 迫田義博, 喜田宏  日本ウイルス学会学術集会プログラム・抄録集  62nd-  154  2014/10/31  [Not refereed][Not invited]
  • 安井文彦, 宗片圭祐, 倉石武, 服部正策, 藤幸知子, 米田美佐子, 迫田義博, 喜田宏, 甲斐知恵子, 小原道法  日本ウイルス学会学術集会プログラム・抄録集  62nd-  235  2014/10/31  [Not refereed][Not invited]
  • 吉田玲子, 伊藤靖, 七戸新太郎, 小笠原一誠, 日尾野隆大, 岡松正敏, 迫田義博, 喜田宏, LE Mai Quynh, 河岡義裕, 五十嵐学, 鈴木定彦, 高田礼人  日本ウイルス学会学術集会プログラム・抄録集  62nd-  234  2014/10/31  [Not refereed][Not invited]
  • 七戸新太郎, 迫田義博, 西達也, 日尾野隆大, 岡松正敏, 伊藤靖, 小笠原一誠, 喜田宏  日本ウイルス学会学術集会プログラム・抄録集  62nd-  154  2014/10/31  [Not refereed][Not invited]
  • 迫田義博, 大河原彩子, 日尾野隆大, 小笠原浩平, 岡松正敏, 喜田宏  日本ウイルス学会学術集会プログラム・抄録集  62nd-  163  2014/10/31  [Not refereed][Not invited]
  • SHIOKAWA MAI, KATO AYANO, FUJIMOTO YURI, ABE YURI, TAMURA TOMOKAZU, NISHINE KAORU, MINE JUNKI, AOKI HIROSHI, FUKUSHO AKIO, KIDA HIROSHI, SAKODA YOSHIHIRO  日本獣医学会学術集会講演要旨集  157th-  396  -396  2014/08/11  [Not refereed][Not invited]
  • 大河原彩子, 日尾野隆大, 小笠原浩平, 岡松正敏, 迫田義博, 喜田宏  日本獣医学会学術集会講演要旨集  157th-  411  2014/08/11  [Not refereed][Not invited]
  • 岡松正敏, DE VRIES Robert, 日尾野隆大, 迫田義博, PAULSON C James, 喜田宏  日本獣医学会学術集会講演要旨集  157th-  419  2014/08/11  [Not refereed][Not invited]
  • 田村友和, RUGGLI Nicolas, 長島尚史, 峯淳貴, 岡松正敏, SUMMERFIELD Artur, HOFMANN Martin A, 喜田宏, 迫田義博  日本獣医学会学術集会講演要旨集  157th-  410  2014/08/11  [Not refereed][Not invited]
  • 塩川愛絵, CHANDIKA Gamage, 小泉信夫, 清水健太, 津田祥美, 迫田義博, 吉松組子, 有川二郎  日本獣医学会学術集会講演要旨集  157th-  379  2014/08/11  [Not refereed][Not invited]
  • 日尾野隆大, 岡松正敏, 五十嵐学, 西原祥子, 高瀬明, 迫田義博, 喜田宏  日本糖質学会年会要旨集  33rd-  62  2014/07/23  [Not refereed][Not invited]
  • 小山田孝嘉, 来馬浩二, 島田俊雄, 迫田義博, 喜田宏  日本DDS学会学術集会プログラム予稿集  30th-  184  2014/07/01  [Not refereed][Not invited]
  • 伊藤靖, 仲山美沙子, 石垣宏仁, 石田英晃, 七戸新太郎, 岡松正敏, 迫田義博, 喜田宏, 喜田宏, 小笠原一誠  日本病理学会会誌  103-  (1)  224  2014/03/26  [Not refereed][Not invited]
  • 伊藤靖, LOI Pham Van, 仲山美沙子, 石垣宏仁, 有方雅彦, 石田英晃, 北川直子, 小笠原一誠, 七戸新太郎, 岡松正敏, 迫田義博, 喜田宏, 喜田宏  滋賀医学  36-  142  2014/03/20  [Not refereed][Not invited]
  • 藤本悠理, 田村友和, 遠藤真由美, 吉野史, RUGGLI Nicolas, 喜田宏, 喜田宏, 迫田義博  日本獣医学会学術集会講演要旨集  157th-  2014
  • 迫田義博  家畜衛生学雑誌  39-  (3)  99  -102  2013/11/22  [Not refereed][Not invited]
  • SAINO HITOSHI, KAWAUCHI KYOKO, USUI AKIRA, ONO HIROSHI, SAKODA YOSHIHIRO, TAJIMA MOTOSHI  日本獣医師会雑誌  66-  (11)  791  -796  2013/11/20  [Not refereed][Not invited]
  • 迫田 義博  家畜衛生学雑誌  39-  (3)  99  -102  2013/11  [Not refereed][Not invited]
  • 西根薫, 青木博史, 長井誠, 宮元みち子, 吉間昌行, 須藤貴之, 迫田義博, 福所秋雄  日本ウイルス学会学術集会プログラム・抄録集  61st-  396  2013/10/29  [Not refereed][Not invited]
  • 安井文彦, 桑原一彦, 飛田良美, 棟方翼, 斉藤誠, 七戸新太郎, 迫田義博, 喜田宏, 阪口薫雄, 小原道法  日本ウイルス学会学術集会プログラム・抄録集  61st-  153  2013/10/29  [Not refereed][Not invited]
  • 直亨則, 梶原将大, 丸山隼輝, 木村享史, MANZOOR Rashid, 村松美笑子, 岡松正敏, 宮本洋子, 吉田玲子, 迫田義博, 喜田宏, 高田礼人  日本ウイルス学会学術集会プログラム・抄録集  61st-  150  2013/10/29  [Not refereed][Not invited]
  • 丸山隼輝, 宮本洋子, 吉田玲子, 前田健, 小川寛人, 迫田義博, 高田礼人  日本ウイルス学会学術集会プログラム・抄録集  61st-  164  2013/10/29  [Not refereed][Not invited]
  • AOKI HIROSHI, NISHINE KAORU, YOSHIMA MASAYUKI, SUDO TAKAYUKI, SAKODA YOSHIHIRO, FUKUSHO AKIO  日本獣医学会学術集会講演要旨集  156th-  264  -264  2013/08/30  [Not refereed][Not invited]
  • 安部優里, 迫田義博, 三津橋和也, 田村友和, 小佐々隆志, 中村成幸, 喜田宏  日本獣医学会学術集会講演要旨集  156th-  265  2013/08/30  [Not refereed][Not invited]
  • 市川貴也, 岡松正敏, 佐藤由佳, 日尾野隆大, 迫田義博, 喜田宏  日本獣医学会学術集会講演要旨集  156th-  269  2013/08/30  [Not refereed][Not invited]
  • 小佐々隆志, 青木博史, 亀山健一郎, 田村友和, 安部優里, 西根薫, 戸高玲子, 片山和彦, 水谷哲也, 白井淳資, 石丸雅敏, 中村成幸, 長井誠, 迫田義博  日本獣医学会学術集会講演要旨集  156回-  265  -265  2013/08  [Not refereed][Not invited]
  • 長井誠, 立石健太郎, 篠原祐太, 鈴木遊大, 福原麻衣, 大森啓太郎, 迫田義博, 青木博史, 水谷哲也, 戸高玲子, 片山和彦, 白井淳資  日本獣医学会学術集会講演要旨集  156回-  265  -265  2013/08  [Not refereed][Not invited]
  • 日尾野隆大, 岡松正敏, 西原祥子, 高瀬明, 迫田義博, 喜田宏  日本獣医学会学術集会講演要旨集  155th-  229  2013/03/04  [Not refereed][Not invited]
  • 曽田公輔, 笛吹達史, 宇野有紀子, 永井泰子, 尾崎弘一, 伊藤啓史, 山本直樹, 田村友和, 日尾野隆大, 岡松正敏, 迫田義博, 高田礼人, 村瀬敏之, 山口剛士, 伊藤壽啓  日本獣医学会学術集会講演要旨集  155th-  83  2013/03/04  [Not refereed][Not invited]
  • 七戸新太郎, 岡松正敏, 迫田義博, 喜田宏  日本獣医学会学術集会講演要旨集  155th-  229  2013/03/04  [Not refereed][Not invited]
  • 迫田義博, 三津橋和也, 田村友和, 長島尚史, 岡松正敏, NICOLAS Ruggli, SUGIRA Parchariyanon, WASANA Pinyochon, 喜田宏  日本獣医学会学術集会講演要旨集  155th-  226  2013/03/04  [Not refereed][Not invited]
  • 和田 淳彦, 迫田 義博, 小山田 孝喜  Fuji Film research & development  (58)  72  -76  2013  [Not refereed][Not invited]
  • 安井文彦, 宗片圭祐, 倉石武, 服部正策, 藤幸知子, 米田美佐子, 迫田義博, 喜田宏, 甲斐知恵子, 小原道法  日本ワクチン学会学術集会プログラム・抄録集  17th-  87  2013  [Not refereed][Not invited]
  • 櫻井陽, 高山勝好, 野村奈美子, 迫田義博, 須田美彦, 小林行治, 阪口薫雄, 喜田宏, 小原道法, 芝崎太  日本分子生物学会年会プログラム・要旨集(Web)  36th-  WEB ONLY 3P-1007  2013  [Not refereed][Not invited]
  • Motofumi Shimizu, Satomi Yanase, O. O. Chang Myint, Masatoshi Okamatsu, Yoshihiro Sakoda, Hiroshi Kida, Hiroshi Takaku  Journal of Vaccines and Vaccination  4-  (6)  2013  [Not refereed][Not invited]
     
    Background: Intermittent outbreaks of highly pathogenic avian influenza virus (flu) infections illustrate the potential for pandemic spread of this deadly disease, thus making the development of sufficient supplies of safe vaccines a necessity. Influenza virus-like particles (Vlps) have been suggested as a promising non-egg or non-mammalian cell culture-based candidate for vaccination against flu. Vlps containing hemagglutinin have previously been shown to promote protection against homologous viral strains. In this report, we describe the development of an H5N1 flu Vlp vaccine involving only three flu viral structural proteins, (i.e., HA, NA, and M1), which were derived from an avian flu A/duck/Hokkaido/vac-1/2004 (H5N1) virus. The H5N1 Vlps produced from insect cells exhibited hemagglutination and neuraminidase activities and generated an immune response in BALB/c mice. We additionally performed viral challenge studies using chickens. Methodology and results: Vlps consisting of the hemagglutinin (HA), neuraminidase (NA), and matrix 1 (M1) proteins of A/duck/Hokkaido/vac-1/2004 (H5N1) were transferred using baculovirus within Spodoptera frugiperda (Sf9) cells. Mice were first immunized with Vlps, and the immune response was compared between animals vaccinated with HA and NA-HA-negative M1 Vlps. The IgG levels of HA-M1 Vlp- and NA-M1 Vlp-treated groups were observed, and 5-fold higher levels of H5N1-specific antibodies were induced in the groups of mice immunized with HA-NA-M1 Vlp. The HA-NA and HA-NA-M1 Vlps vaccines induced IgG2a and IgG2b antibodies as well as IgG1 antibodies, indicating that both Th1 and Th2 immune responses were induced. Furthermore, NA-M1 immunization induced IgG and IgG1 isotype antibodies and led to low levels of IgG2a and IgG2b. Additionally, all chickens immunized with HA-NA-M1 Vlp were protected against deadly infections with the highly pathogenic avian flu virus A/chicken/Yamaguchi/4/2004 (H5N1). Conclusions: Intramuscular administration of H5 Vlps conferred immunity against a deadly viral challenge. The H5 Vlp vaccine was more successful at raising Th1-biased protective responses, including IgG2a production. Thus, flu Vlps offer an important approach for immunization, especially if a pandemic occurs. Recognizing the current state of vaccination strategies, it is imperative to investigate the associated immunogenicity and defensive capabilities of H5 Vlps in comparison with inactivated whole virus and attenuated live H5N1 viruses. These results support the continued development of Vlps as a formulation for a vaccine against flu infection. © 2013 Shimizu M, et al.
  • 山本 直樹, 迫田 義博  獣医畜産新報  65-  (11)  901  -906  2012/11  [Not refereed][Not invited]
  • 岡本成史, 竹中延之, 迫田義博, 岡松正敏, 山本直樹, ハリディ アーマド, 山田博司, 森康子, 喜田宏, 山西弘一  日本ウイルス学会学術集会プログラム・抄録集  60th-  263  2012/10/31  [Not refereed][Not invited]
  • 田村友和, 長島尚史, 山本直樹, 岡松正敏, NICOLAS Ruggli, 迫田義博, 喜田宏  日本ウイルス学会学術集会プログラム・抄録集  60th-  250  2012/10/31  [Not refereed][Not invited]
  • 七戸新太郎, 岡松正敏, 迫田義博, 喜田宏  日本ウイルス学会学術集会プログラム・抄録集  60th-  167  2012/10/31  [Not refereed][Not invited]
  • NISHINE KAORU, ENOKIDO MASATO, AOKI HIROSHI, SAKODA YOSHIHIRO, FUKUSHO AKIO  日本獣医学会学術集会講演要旨集  154th-  251  -251  2012/08/31  [Not refereed][Not invited]
  • 山本 直樹, 迫田 義博  畜産技術  0-  (686)  19  -24  2012/07  [Not refereed][Not invited]
  • SAKODA Yoshihiro, ENDO Mayumi, SATO Yuka, OKAMATSU Masatoshi, KIDA Hiroshi  Journal of the Japan Veterinary Medical Association  65-  (4)  303  -305  2012/04/20  [Not refereed][Not invited]
     
    The inactivation of avian influenza virus using disinfectant including glutaraldehyde was investigated. The disinfectant showed sufficient effect to inactivate avian influenza virus with contamination of fecal materials in the mixture. However, the effectiveness of the disinfectant was limited under conditions with low reaction temperature. In addition, the disinfectant requires a longer reaction time to inactivate avian influenza virus than that of cationic detergent. It was concluded that disinfectant containing glutaraldehyde was effective to inactivate avian influenza viruses under appropriate conditions.
  • 長島尚史, 迫田義博, 田村友和, 山本直樹, 岡松正敏, NICOLAS Ruggli, 喜田宏, 喜田宏  日本ウイルス学会学術集会プログラム・抄録集  60th-  2012
  • 長島尚史, 迫田義博, 田村友和, 栗林沙弥, 山本直樹, 岡松正敏, RUGGLI Nicolas, 喜田宏, 喜田宏  日本獣医学会学術集会講演要旨集  153rd-  2012
  • 安部優里, 迫田義博, 三津橋和也, 田村友和, 長島尚史, 岡松正敏, 長井誠, 喜田宏, 喜田宏  日本獣医学会学術集会講演要旨集  154th-  2012
  • SAKODA Yoshihiro  Uirusu  61-  (2)  239  -248  2011/12/01  [Not refereed][Not invited]
     
    Members of the genus Pestivirus, are causative agents of economically important diseases for livestock and wild animals that occur worldwide, such as bovine viral diarrhea, classical swine fever, and border disease of sheep. Pestivirus have novel insertions of host genes in the viral genome and functions of unique viral proteins, Npro and Erns, related to the pathogenicity although genomic structure is closely related to the other viruses of Flaviviridae family, especially hepatitis C virus. In this review, recent studies on the molecular basis of pathogenicity of pestivirus infections were summarized.
  • 迫田 義博  グリーンテクノ情報  7-  (2)  9  -13  2011/10  [Not refereed][Not invited]
  • 内田 裕子, 金平 克史, 真瀬 昌司, 竹前 喜洋, 渡辺 千晶, 笛吹 達史, 藤本 佳万, 伊藤 壽啓, 五十嵐 学, 伊藤 公人, 高田 礼人, 迫田 義博, 岡松 正敏, 山本 祐, 中村 菊保, 喜田 宏, 廣本 靖明, 津田 知幸, 西藤 岳彦  動物衛生研究成果情報  (10)  15  -16  2011/09  [Not refereed][Not invited]
  • NISHINE KAORU, AOKI HIROSHI, SAKODA YOSHIHIRO, FUKUSHO AKIO  日本獣医学会学術集会講演要旨集  152nd-  245  -245  2011/08/31  [Not refereed][Not invited]
  • 岡松正敏, 伊藤啓史, 内田裕子, 迫田義博, 山本直樹, 曽田公輔, 笛吹達史, 尾崎弘一, 山口剛士, 村瀬敏之, 伊藤壽啓, 西藤岳彦, 喜田宏  日本獣医学会学術集会講演要旨集  152nd-  231  2011/08/31  [Not refereed][Not invited]
  • NISHINE Kaoru, AOKI Hiroshi, SAKODA Yoshihiro, FUKUSHO Akio  Journal of Veterinary Epidemiology  16-  (1)  19  -20  2011  [Not refereed][Not invited]
     
    The purpose of this study was to detect and quantify bovine viral diarrhea virus (BVDV) quasispecies in field endemic BVDV strains, and to analyze a co-relation between quantity of these quasispieces and variety of clinical sign on bovine viral diarrhea virus infections.<BR>Forty five of BVDV isolates in Hokkaido prefecture were analyzed by the exaltation of Newcastle disease virus (END) method, the reverse plaque formation (RPF) method using vesicular stomatitis virus, and observation of cytopathic effect (CPE). As a result, these isolates investigated were divided into five groups. The first group is 10 isolates from which END phenomenon positive (E<SUP>+</SUP>) virus was only detected. The second is 25 isolates which consisted of E<SUP>+ </SUP>virus as major and END phenomenon negative (E<SUP>-</SUP>) virus as minor. The third is 7 isolates in which each virus was detected with same titer. The fourth is 2 isolates which showed only E<SUP>-</SUP> virus-positive. The fifth is 1 isolate which contained cp virus. In the quantitative analysis, it was shown that the ratio of E<SUP>-</SUP> virus against E<SUP>+</SUP> virus in the strain that contained each virus varied from 2 times to 435 times. These results suggest that BVDV field isolates not only consist of E<SUP>+</SUP> virus as major virus but also contain several quantity of E<SUP>-</SUP> virus as minor virus, and that E<SUP>-</SUP> virus exists frequently in the field. Moreover, it is interesting that the strains with E<SUP>-</SUP> virus as major are in the field, which will be a first report. On the other hand, any co-relations between quantity of E<SUP>-</SUP> virus in the field strain and epidemiological dynamism such as animal age, clinical symptoms of BVD-MD, or BVDV genotype, were not found unfortunately. However, there is the possibility of exerting an impact on symptom, because every isolates couldn&rsquo;t detect E<SUP>-</SUP>virus have been derived from asymptomatic infected cows.
  • 迫田義博, 田村友和, 長島尚史, 山本直樹, 岡松正敏, RUGGLI Nicolas, 喜田宏, 喜田宏  日本獣医学会学術集会講演要旨集  152nd-  2011
  • 田村友和, 迫田義博, 吉野史, 長島尚史, 山本直樹, 佐藤由佳, 岡松正敏, RUGGLI Nicolas, 喜田宏, 喜田宏  日本獣医学会学術集会講演要旨集  152nd-  2011
  • TAMURA TOMOKAZU, SAKODA YOSHIHIRO, YOSHINO FUMI, SUGITA MASAHIKO, OKAMATSU MASATOSHI, NAGAI MAKOTO, ITO MIKA, AOKI HIROSHI, KIDA HIROSHI  日本ウイルス学会学術集会プログラム・抄録集  58th-  275  2010/10/15  [Not refereed][Not invited]
  • 迫田 義博  農家の友  62-  (10)  82  -84  2010/10  [Not refereed][Not invited]
  • TAKAHASHI NATSUMI, AOKI HIROSHI, MATSUURA YUKIKO, YAMAMOTO TOSHIAKI, SAKODA YOSHIHIRO, FUKUSHO AKIO  日本獣医学会学術集会講演要旨集  150th-  234  -234  2010/09/01  [Not refereed][Not invited]
  • TAMURA TOMOKAZU, SAKODA YOSHIHIRO, YOSHINO FUMI, OKAMATSU MASATOSHI, NAGAI MAKOTO, ITO MIKA, AOKI HIROSHI, KIDA HIROSHI  日本獣医学会学術集会講演要旨集  150th-  234  -234  2010/09/01  [Not refereed][Not invited]
  • E. -O. Tseren-Ochir, B. Damdinjav, T. Sharkhuu, H. M. Kang, Y. Sakoda, B. Purevsuren, S. Ruuragchaa, Y. J. Lee, H. Kida, B. Khishgee, S. Sengee  INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES  14-  E164  -E165  2010/03  [Not refereed][Not invited]
  • 田村友和, 迫田義博, 杉田征彦, 吉野史, 岡松正敏, 喜田宏, 喜田宏  日本獣医学会学術集会講演要旨集  149th-  2010
  • 迫田義博, 田村友和, 杉田征彦, 吉野史, 岡松正敏, 喜田宏, 喜田宏  日本ウイルス学会学術集会プログラム・抄録集  58th-  2010
  • 曽田公輔, 浅倉真吾, 岡松正敏, 迫田義博, 喜田宏, 喜田宏  日本獣医学会学術集会講演要旨集  149th-  2010
  • ISODA Norikazu, SAKODA Yoshihiro  農林水産技術研究ジャーナル  32-  (12)  10  -15  2009/12/01  [Not refereed][Not invited]
  • T. Tanaka, Y. Sunden, G. Tanoue, K. Ochiai, Y. Sakoda, H. Kida, T. Umemura  JOURNAL OF COMPARATIVE PATHOLOGY  141-  (4)  277  -277  2009/11  [Not refereed][Not invited]
  • 磯田 典和, 迫田 義博, 喜田 宏  化学と生物  47-  (5)  302  -304  2009/05/01  [Not refereed][Not invited]
  • SAKODA Yoshihiro  農林水産技術研究ジャーナル  32-  (3)  52  -56  2009/03/01  [Not refereed][Not invited]
  • 佐々木 崇, 坂元 隆一, 今村 孝, 坂口 正士, 瀧川 義康, 西條 加須江, 澤田 章, 萩原 純子, 土屋 耕太郎, 林 志鋒, 國米 則秀, 扇谷 年昭, 曽田 公輔, 磯田 典和, 迫田 義博, 喜田 宏  鶏病研究会報  44-  (4)  170  -174  2009/02/25  [Not refereed][Not invited]
  • 曽田公輔, 浅倉真吾, 岡松正敏, 迫田義博, 喜田宏, 喜田宏  日本ウイルス学会学術集会プログラム・抄録集  57th-  2009
  • 本島昌幸, 岡松正敏, 浅倉真吾, 伊藤美加, 前田友起子, 福田奈穂, SODNOMDARJAA R., 迫田義博, 喜田宏, 喜田宏  日本ウイルス学会北海道支部夏季シンポジウム講演抄録  43rd-  2009
  • 伊藤靖, 尾崎弘一, 曽田公輔, 迫田義博, 石垣宏仁, 仲山美沙子, 石田英晃, 永田智也, 三宅太一郎, 喜田宏, 喜田宏, 小笠原一誠  日本ワクチン学会学術集会プログラム・抄録集  13th-  2009
  • 岡松正敏, 迫田義博, 吉田裕美, 田中智久, 津田祥美, 磯田典和, 中山絵里, 苫米地大輔, 松野啓太, 梅村孝司, 高田礼人, 喜田宏  日本ウイルス学会学術集会プログラム・抄録集  56th-  263  2008/10/01  [Not refereed][Not invited]
  • 岡松正敏, 迫田義博, 吉田裕美, 田中智久, 津田祥美, 磯田典和, 中山絵里, 苫米地大輔, 松野啓太, 梅村孝司, 高田礼人, 喜田宏  日本獣医学会学術集会講演要旨集  146th-  193  2008/09/05  [Not refereed][Not invited]
  • Mika Ito, Makoto Nagai, Yuji Hayakawa, Hirofumi Komae, Naruto Murakami, Syouichi Yotsuya, Shingo Asakura, Yoshihiro Sakoda, Hiroshi Kida  JOURNAL OF VETERINARY MEDICAL SCIENCE  70-  (9)  899  -906  2008/09  [Not refereed][Not invited]
     
    In August 2007, an outbreak of equine influenza occurred among vaccinated racehorses with Japanese commercial equine influenza vaccine at Kanazawa Racecourse in Ishikawa prefecture in Japan. Apparent symptoms were pyrexia (38.2-41.0 degrees C) and nasal discharge with or without coughing, although approximately half of the infected horses were subclinical. All horses had been shot with a vaccine that contained two inactivated H3N8 influenza virus strains [A/equine/La Plata/93 (La Plata/93) of American lineage and A/ equine/Avesta/93 (Avesta/93) of European lineage] and an H7N7 strain (A/equine/Newmarket/1/77). Influenza virus, A/equine/ Kanazawa/1/2007 (H3N8) (Kanazawa/07), was isolated from one of the nasal swab samples of diseased horses. Phylogenetic analysis indicated that Kanazawa/07 was classified into the American sublineage Florida. In addition, four amino acid substitutions were found in the antigenic sites B and E in the HA1 subunit protein of Kanazawa/07 in comparison with that of La Plata/93. Hemagglutination-inhibition (HI) test using 16 serum samples from recovering horses revealed that 1.4- to 8-fold difference in titers between Kanazawa/ 07 and either of the vaccine strains. The present findings suggest that Japanese commercial inactivated vaccine contributed to reducing the morbidity rate and manifestation of the clinical signs of horses infected with Kanazawa/07 that may be antigenically different from the vaccine strains.
  • Rashid Manzoor, Yoshihiro Sakoda, Saori Sakabe, Tsuyoshi Mochizuki, Yasuharu Namba, Yoshimi Tsuda, Hiroshi Kida  JOURNAL OF VETERINARY MEDICAL SCIENCE  70-  (6)  557  -562  2008/06  [Not refereed][Not invited]
     
    As well as H5 highly pathogenic avian influenza viruses (HPAIV), H7 HPAIV strains have caused serious damages in poultry industries worldwide. Cases of bird-to-human transmission of H7 HPAIV have also been reported [I I]. On the outbreak of avian influenza, rapid diagnosis is critical not only for the control of HPAI but also for human health. In the present study, a rapid diagnosis kit based on immunochromatography for the detection of H7 hemagglutinin (HA) antigen of influenza A virus was developed using 2 monoclonal antibodies that recognize different epitopes on the H7 HAS. The kit detected each of the tested 15 H7 influenza virus strains and did not react with influenza A viruses of the other subtypes than H7 or other avian viral and bacterial pathogens. The kit detected H7 HA antigen in the swabs and tissue homogenates of the chickens experimentally infected with HPAIV strain A/chicken/Netherlands/2586/03 (H7N7). The results indicate that the present kit is specific and sensitive enough for the diagnosis of HPAI caused by H7 viruses, thus, recommended for the field application as a pen-site test kit.
  • Tomohisa Tanaka, Ginpei Tanoue, Masahiro Yamasaki, Ikuo Takashima, Yoshihiro Sakoda, Kenji Ochiai, Takashi Umemura  JOURNAL OF VETERINARY MEDICAL SCIENCE  70-  (6)  607  -610  2008/06  [Not refereed][Not invited]
     
    Many small wild birds died in the 2005-2006 wintertime in Hokkaido. Thirteen birds were pathologically examined and it was attempted to detect West Nile and influenza viruses from their organs. Consecutive pathological changes were fresh hemorrhage and acute circulatory failure. Viral detections were negative. Selective occurrence in wintertime, literature review and the results Of pathological and virological examinations Suggested chemical deicer poisoning as the cause of wild bird death. Chicks treated orally with deicer showed acute death and their pathological changes were similar to those of the wild birds. Because the chicks showed significant elevation of plasma Na concentration, plasma electrolyte analysis of the affected wild birds might be crucial to confirm Our tentative diagnosis.
  • ITO Asako, SAKODA Yoshihiro, KAMEYAMA Ken-ichiro, YAMAZAKI Yukio, USUI Akira, KIDA Hiroshi  Journal of the Japan Veterinary Medical Association  61-  (1)  39  -42  2008/01/20  [Not refereed][Not invited]
     
    牛ウイルス性下痢病（BVD）と牛伝染性鼻気管炎の予防に効果的なワクチン接種プログラムを評価するために、BVDに対して不活化抗原を含有する2つの市販混合ワクチンをそれぞれ抗体陰性牛に接種した。いずれのワクチンも初回接種後の牛にBVDウイルスおよび牛ヘルペスウイルス1に対する中和抗体がほとんど検出されなかったが、2回目の接種1ヵ月後に有意な抗体応答を認めた。その後、抗体価は時間の経過とともに漸減したが、初回接種から12ヵ月後に1回追加免疫を行うことにより抗体価が再上昇した。以上の成績より、抗体陰性牛に対する本疾病の効果的な予防には今回評価したワクチンは2回接種する必要があること、さらに年1回の追加接種が望ましいことが明らかになった。
  • 浅倉真吾, 浅倉真吾, 迫田義博, 迫田義博, 長井誠, 若本裕昌, 喜田宏, 喜田宏, 喜田宏  日本ウイルス学会学術集会プログラム・抄録集  56th-  2008
  • 浅倉真吾, 迫田義博, 伊藤美加, 長井誠, 前田友起子, 福田奈穂, 阿部修二, BATCHULUUN D., SODNOMDARJAA R., 若本裕晶, 岡松正敏, 喜田宏, 喜田宏  日本獣医学会学術集会講演要旨集  146th-  2008
  • 曽田公輔, 曽田公輔, 浅倉真吾, 浅倉真吾, 岡松正敏, 岡松正敏, 迫田義博, 迫田義博, 喜田宏, 喜田宏, 喜田宏  日本獣医学会学術集会講演要旨集  146th-  2008
  • 曽田公輔, 曽田公輔, 浅倉真吾, 浅倉真吾, 岡松正敏, 岡松正敏, 迫田義博, 迫田義博, 喜田宏, 喜田宏, 喜田宏  日本ウイルス学会学術集会プログラム・抄録集  56th-  2008
  • Kouichi Ozaki, Yasuto Umeda, Shigeyuki Aoyama, Norikazu Isoda, Masatoshi Okamatsu, Yoshihiro Sakoda  VACCINE  2008  [Not refereed][Not invited]
  • 新矢 恭子, 迫田 義博, 河岡 義裕  インフルエンザ  9-  (1)  11  -19  2008/01  [Not refereed][Not invited]
  • 迫田 義博  日本獣医師会雑誌 = Journal of the Japan Veterinary Medical Association  60-  (12)  817  -819  2007/12/20  [Not refereed][Not invited]
  • 迫田 義博  日本獣医師会雑誌  60-  (12)  817  -819  2007/12  [Not refereed][Not invited]
  • Jae-Ho Shin, Yoshihiro Sakoda, Jae Hoon Kim, Kenji Ochiai, Takashi Umemura  JOURNAL OF VETERINARY MEDICAL SCIENCE  69-  (11)  1167  -1169  2007/11  [Not refereed][Not invited]
     
    Rabbits were immunized with inactivated influenza virus via the subarachnoidal (SA) or subcutaneous (SC) route, and the antibody titers in cerebrospinal fluid (CSF) and serum were assayed. There were no nervous signs or morphological lesions related to SA immunization. In the SC group, the antibody titer was elevated in serum, but not elevated in CSF. In the SA group, the antibody titer was significantly elevated in serum and even in CSF, and their antibody titers were much greater than in the SC group. The present results suggest that intrathecal immunization is more effective than SC immunization at inducing a protective immune response against the transneural spread of viruses.
  • 梶原将大, 梶原将大, 迫田義博, 迫田義博, 伊藤壽啓, 高田礼人, 岸田典子, 五十嵐学, 磯田典和, 磯田典和, 曽田公輔, 曽田公輔, 喜田宏, 喜田宏, 喜田宏  日本ウイルス学会学術集会プログラム・抄録集  55th-  216  2007/10/01  [Not refereed][Not invited]
  • 亀山 健一郎, 迫田 義博  獣医畜産新報  60-  (10)  818  -822  2007/10  [Not refereed][Not invited]
  • 梶原将大, 梶原将大, 迫田義博, 迫田義博, 伊藤壽啓, 高田礼人, 伊藤公人, 岸田典子, 五十嵐学, 磯田典和, 磯田典和, 曽田公輔, 曽田公輔, WEBSTER R.G, 喜田宏, 喜田宏, 喜田宏  日本獣医学会学術集会講演要旨集  144th-  91  2007/08/27  [Not refereed][Not invited]
  • SAKODA Yoshihiro, YOSHIMI Yasushi, KUROKAWA Satoru, KIDA Hiroshi  Journal of the Japan Veterinary Medical Association  60-  (7)  519  -522  2007/07/20  [Not refereed][Not invited]
     
    市販消毒薬5品の鳥インフルエンザウイルス不活化効果を調べた。消毒薬はいずれもウイルスの亜型と病原性に関わらず、高希釈でウイルスの感染性を消失させた。希釈した薬液の凍結融解の繰り返しは消毒効果に影響を与えなかったが、低温下および有機物として鶏糞を添加した場合、消毒効果の減少が認められた。以上の結果から、試験に用いた消毒薬は反応温度や有機物の混入などの環境要因を十分に理解した上で適切に使用すれば鳥インフルエンザウイルスの不活化に有効であることがわかった。
  • 迫田 義博, 吉見 泰, 黒川 知  Journal of the Japan Veterinary Medical Association  60-  (7)  519  -522  2007/07  [Not refereed][Not invited]
     
    市販消毒薬5品の鳥インフルエンザウイルス不活化効果を調べた。消毒薬はいずれもウイルスの亜型と病原性に関わらず、高希釈でウイルスの感染性を消失させた。希釈した薬液の凍結融解の繰り返しは消毒効果に影響を与えなかったが、低温下および有機物として鶏糞を添加した場合、消毒効果の減少が認められた。以上の結果から、試験に用いた消毒薬は反応温度や有機物の混入などの環境要因を十分に理解した上で適切に使用すれば鳥インフルエンザウイルスの不活化に有効であることがわかった。
  • 迫田 義博, 喜田 宏  鶏病研究会報  43-  (1)  32  -33  2007/05/25  [Not refereed][Not invited]
  • Keita Matsuno, Yoshihiro Sakoda, Ken-ichiro Kameyama, Kyuzo Tamai, Asako Ito, Hiroshi Kida  JOURNAL OF VETERINARY MEDICAL SCIENCE  69-  (5)  515  -520  2007/05  [Not refereed][Not invited]
     
    The 475 strains of bovine viral diarrhea virus (BVDV) isolated from cattle in 12 prefectures of Japan in the last 7 years were phylo.genetically classified as BVDV-1 or BVDV-2 on the basis of the nucleotide sequence of the 5'-untransiated region. BVDV-1 strains were further subtyped as 1a (101 strains), 1b (163), 1c (128), 1j (3), and So CP/75-like (1), and all of the 79 BVDV-2 strains belonged to subtype 2a. These 2a BVDVs contain two isolates that had high nucleotide identities with those of highly pathogenic BVDV-2 strains reported in North America (Pellerin et al., 1994). However, acute infection with severe mortality like North American outbreak was not observed and most of the present BVDV-2 strains were isolated from persistently infected (PI) cattle showing mild or no clinical sign. Moreover, it was revealed that 61.5% of the 39 PI cattle with cytopathogenic BVDVs did not show typical mucosal disease and 54.6% of the 405 PI animals only with non-cytopathogenic BVDVs were apparently healthy. The present results indicate that the prevention of the infection with an appropriate vaccine and active surveillance covering healthy cattle are required for the control of BVD.
  • 迫田 義博, 関 令二, 喜田 宏  The Japanese journal of animal hygiene  32-  (2)  67  -70  2007/03  [Not refereed][Not invited]
  • Kei Fujii, Chiharu Kakumoto, Mari Kobayashi, Sachiko Saito, Tatsuya Kariya, Yukiko Watanabe, Yoshihiro Sakoda, Hiroshi Kida, Masatsugu Suzuki  JOURNAL OF VETERINARY MEDICAL SCIENCE  69-  (3)  259  -263  2007/03  [Not refereed][Not invited]
     
    For proper management and conservation of the Kuril harbor seal (Phoca vitulina stejnegeri) through disease control, serological analysis was performed for influenza A virus infection in free-ranging seals in Hokkaido, Japan. Serum samples were collected from seals at Nosappu (231 seals), Akkeshi (16) and Erimo (75), between 1998 and 2005, and were analyzed by ELISA. Antibodies to the influenza A virus were detected only in seals from Nosappu. The incidences were 11% (1/9), 3% (2/66), 12% (7/59) and 6% (5/77) in 1998, 2003, 2004 and 2005, respectively. These suggest sporadic infection. Because anti body-positive seals included juvenile seals in each year, the infections were considered to have been circulated since no later than the late 1990s until recent years. ELISA-positive sera were analyzed by hemagglutination inhibition (HI) tests to determine the subtypes. Antibodies to the H3 and H6 subtypes were detected in 10 and 2 sera, respectively. Two of the sera that had antibodies to the H6 subtype also had antibodies to the H3 subtype. These two seals were considered to have been infected with both the H3 and H6 subtypes. This is the first investigation to find antibodies to the H6 subtype in seals. Although the H6 subtype had been isolated only from avians, genetic analysis had suggested that the H6 subtype could become a novel mammalian pathogen. For definitive diagnosis, detection of the virus from the tissue or mucus of seals is required.
  • Jae-Ho Shin, Yoshihiro Sakoda, Jae Hoon Kim, Tomohisa Tanaka, Hiroshi Kida, Takashi Kimura, Kenji Ochiai, Takashi Umemura  JOURNAL OF NEUROIMMUNOLOGY  178-  114  -114  2006/09  [Not refereed][Not invited]
  • 迫田 義博  インフルエンザ  7-  (3)  195  -200  2006/07  [Not refereed][Not invited]
  • 迫田 義博  畜産技術  0-  (611)  34  -36,図巻頭1p  2006/04  [Not refereed][Not invited]
  • GR Bai, Y Sakoda, AS Mweene, N Fujii, H Minakawa, H Kida  JOURNAL OF VETERINARY MEDICAL SCIENCE  68-  (1)  35  -40  2006/01  [Not refereed][Not invited]
     
    To improve the sensitivity of a kit, ESPLINE (R) INFLUENZA A&B for rapid diagnosis of influenza by detecting influenza A or B virus specific nucleoproteins (NP), the ESPLINE (R) INFLUENZA A&B-N was developed by using newly established monoclonal antibodies (MAbs) to the respective NP molecule. MAbs FVA2-11 and FrB1-03 recognize the epitope on the amino acid region 59-130aa of the NP molecule of influenza A virus, and that on the region 72-191aa of the NP of influenza B virus, respectively. The new kit detected influenza A and B virus antigens with a detection limit of 10(2.0)-10(2.7) pfu/test, which is 4-1000 times higher than that of the original kit. Importantly, this kit detected each of influenza A viruses of the known hemagglutinin (HA) subtypes (H1-H15) including the H5N1 viruses recently isolated from human and avian sources in Asia. The kit also detected all of the 15 representative influenza B virus strains tested. The ESPLINE (R) INFLUENZA A&B-N is thus a rapid and highly sensitive and specific kit for the diagnosis of either influenza A or B virus infections.
  • H Aoki, Y Sakoda, S Nakamura, S Suzuki, A Fukusho  JOURNAL OF VETERINARY MEDICAL SCIENCE  66-  (2)  161  -167  2004/02  [Not refereed][Not invited]
     
    Pestiviruses can be distinguished as two biotypes, cytopathogenic (cp) and noncytopathogenic (noncp), by the morphological changes that they induce during growth in cultured cells. In this study, the cp phenotype of several classical swine fever viruses (CSFV) was evaluated by the detections of the nonstructural proteins NS2-3 and NS3 using immunoprecipitation and Western blotting in different porcine cell lines. Most CSFVs that showed the exaltation of Newcastle disease virus (END) phenomenon (END+ viruses) did not induce cytopathic effect (CPE)in any cell line, and detections of NS2-3 and NS3 showed a strong signal for NS2-3 in the END+ virus-infected cells. However, clear CPE was observed in serum-free cultured cells (FS-L3 and CPK-NS) infected with viruses that induce intrinsic interference but did not show the END phenomenon (END- viruses), and signal of NS3 was strongly detected than that of NS2-3 in these cells at 72 hr after infection. As the results of the analysis of FS-L3 cells infected with ALD (END+ virus) and ALD-END- virus (END- virus) at several incubations, the signal of NS3 detected was strengthened with CPE that become evident progressively. These results suggest that CPE is associated with the accumulation of NS3, which is promoted in serum-free cell lines infected with END- viruses. Thus, indicating there is a close relationship between CPE and the quantity of NS3 produced in END- CSFV infection.
  • YAEGASHI Gakuji, SEIMIYA Yukio M, SAKODA Yoshihiro, SEKI Yoshihisa  Journal of the Japan Veterinary Medical Association  57-  (1)  31  -35  2004/01/20  [Not refereed][Not invited]
     
    1987年から2002年までの16年間に岩手県内21農場33頭の牛から分離された牛ウイルス性下痢ウイルス（BVDV）33株の5'末端非翻訳領域を分子系統的に解析した。分離株は遺伝子型別に17株が1a型、3株が1a'型、9株が1b型そして4株が2型に分類された。2型に分類された4株の塩基配列は同一であり、2型BVDVの病原性決定塩基と考えられている219および278番目の塩基は強毒型とは異なっていた。また、2型株が分離された牛に全身性の出血病変は観察されなかった。2001年に採取した県内145農場725頭の牛血清中に2型特異抗体は認められなかった。これらの結果は2型を含む多様な遺伝子型のBVDV株が県内に浸潤していること、および2型株の浸潤範囲は限局的であることを示唆する。
  • TAMAI KYUZO, SAKODA YOSHIHIRO, AOKI HIROSHI, NAKAMURA SHIGEYUKI, KIDA HIROSHI  日本獣医学会学術集会講演要旨集  135th-  131  -131  2003/03/25  [Not refereed][Not invited]
  • SUZUKI SHOKO, SAKODA YOSHIHIRO, SEKIGUCHI HIDETO, AOKI HIROSHI, TAKAHASHI CHIKAKO, NISHIGUCHI AKIKO, ETO MARIKO  日本獣医学会学術集会講演要旨集  132nd-  180  -180  2001/09/07  [Not refereed][Not invited]
  • 迫田 義博  養豚の友  (389)  31  -34  2001/08  [Not refereed][Not invited]
  • SAKOTA Y  日本豚病研究会報 = Proceedings of the Japanese Pig Veterinary Society  38-  (0)  14  -17  2001/08/01  [Not refereed][Not invited]
  • H Aoki, K Ishikawa, Y Sakoda, H Sekiguchi, M Kodama, S Suzuki, A Fukusho  JOURNAL OF VETERINARY MEDICAL SCIENCE  63-  (7)  751  -758  2001/07  [Not refereed][Not invited]
     
    Classical swine fever virus (CSFV) strain WB82, isolated from a wild boar in 1982, induced a distinct cytopathic effect (CPE) in primary swine testicle cell culture and in most of the porcine cell lines. This strain of CSFV was found to be composed of two biotypes, cytopathogenic (cp) CSFV, as a minor population, and noncytopathogenic (noncp) CSFV, as a major population. The noncp CSFV (designated strain WB82/E+) was obtained by biological cloning, and it showed the exaltation of Newcastle disease virus phenomenon. In Northern blot analysis and RT-PCR assay, CSFV RNA with a subgenomic (sg) length was detected in addition to full-length viral RNA only in the cells in which a CPE had been revealed, These RNAs represent the genomes of typical defective interfering (DI) particles because of the strict dependence on a complementing helper virus and interference with replication of the helper virus. The sg RNA, which exhibits the genomes of the DI particles, lacked the nucleotides of the viral genomic region from N-pro to NS2 (4764 bases). When extracted sg RNA was transfected to the cells infected with the WB82/E+ strain, a distinct CPE was observed. Interestingly, the CPE was observed in cells infected with other heterologous noncp CSFV ALD and GPE(-) strains by sg RNA transfection. The results suggested that these noncp CSFVs act as helper viruses for the replication of sg RNA (DI particles). It was also shown that the cytopathogenicity of strain WB82 is caused by apoptosis.
  • 井上 亙, 迫田 義博  畜産技術  0-  (552)  34  -35,図巻頭1p  2001/05  [Not refereed][Not invited]
  • 本道 栄一, 迫田 義博  動生協会々報  34-  (1)  64  -66  2001/01  [Not refereed][Not invited]
  • INOUE WATARU, KOKUBO TAKEHIRO, SAKOTA YOSHIHIRO, INUMARU SHIGEKI, AOKI HIROSHI, YAMADA SHUNJI, YOSHII MASAAKI, FUKUSHO AKIO, YOKOMIZO YUICHI  日本獣医学会学術集会講演要旨集  130th-  255  2000/09/07  [Not refereed][Not invited]
  • AOKI HIROSHI, ISHIKAWA KIYOYASU, SEKIGUCHI HIDETO, GAMO KOICHIRO, SAKOTA YOSHIHIRO, TAKAHASHI SHUKO, SUZUKI SHOKO, FUKUSHO AKIO  日本獣医学会学術集会講演要旨集  128th-  151  -151  1999/09/01  [Not refereed][Not invited]
  • AOKI HIROSHI, ISHIKAWA KIYOYASU, SAKOTA YOSHIHIRO, SEKIGUCHI HIDETO, GAMO KOICHIRO, SUZUKI YOSHIKO, FUKUSHO AKIO  日本獣医学会学術集会講演要旨集  127th-  117  -117  1999/03/01  [Not refereed][Not invited]
  • FS-L3細胞を用いた豚コレラウイルスの新しいアッセイ法の確立
    Journal of Virological Methods.  70-  (1)  93  -101  1999  [Not refereed][Not invited]
  • Yoshihiro Sakoda, Osamu Yamaguchi, Akio Fukusho  Journal of Virological Methods  70-  (1)  93  -101  1998/01  [Not refereed][Not invited]
     
    A new assay termed the dome disappearance method for classical swine fever virus (CSFV) using FS-L3 cells with serum-free culture medium was developed. The CSFV live vaccine GPE- strain grows well and shows a slight cytopathic effect (CPE) in FS-L3 cells. This CPE results in the disappearance of the unique fluid-filled multicellular domes on a single monolayer of FS-L3 cells. By using this phenomenon, dome disappearance, as a marker of infection, it was possible to determine the titers of CSFV and its neutralizing antibody. The virus titer determined by this method shows a good correlation with that determined by immunochemical and interference methods. Furthermore, the amount of neutralizing antibody measured by this method also correlated with that measured by the Exaltation of Newcastle Disease Virus (END) neutralizing method. The dome disappearance method developed in this experiment is a simple and safe procedure and has the great advantage that bovine serum, which may contain antibody against bovine viral diarrhea virus, is not necessary for the cultivation of FS-L3 cells.
  • YAMAGUCHI Osamu, SAKODA Yoshihiro, SATO Mitsuo, NAKAMURA Shigeyuki, FUKUSHO Akio  Journal of the Japan Veterinary Medical Association  50-  (11)  639  -644  1997/11/20  [Not refereed][Not invited]
     
    All genes of classical swine fever viruses (CSFV) and bovine viral diarrhea viruses (BVDV) were detected by RT-PCR using primers located in the 5' non-coding region. Discrimination between CSFV and BVDV was performed easily by restriction endonuclease (>Bgl I andPstI) analysis of amplified PCR fragments.
  • ISHIKAWA KIYOYASU, SAKOTA YOSHIHIRO, KODAMA MICHI, HIKAWA MIFUYU, TSUCHIYA YOSHINORI, SEKIGUCHI HIDETO, AOKI HIROSHI, SUZUKI SHOKO, FUKUSHO AKIO  日本獣医学会学術集会講演要旨集  124th-  71  1997/09  [Not refereed][Not invited]
  • S Nakamura, K Sakamoto, Y Sakoda, T Shimazaki, Y Inoue, N Ogawa, A Fukusho  JOURNAL OF VETERINARY MEDICAL SCIENCE  59-  (5)  361  -370  1997/05  [Not refereed][Not invited]
     
    Non-cytopathogenic (NCP) viruses of bovine viral diarrhea (BVD) virus were detected at a low ratio by the reverse plaque formation method from virus samples after several plaque clonings of cytopathogenic (CP) BVD viruses; NADL and Osloss strains. This phenomenon suggests that the NCP BVD viruses are produced at a low ratio during the propagation of CP BVD viruses in vitro. To investigate the differences between the parent CP BVD virus and the NCP BVD virus as a real progeny, the regions flanking the insertion of cellular mRNA in the p125 domain of NADL and Osloss strains were amplified by RT-PCR and cloned into pGEM 3Z plasmid vector, and then sequenced. Consequently, it was confirmed that sequences of cellular mRNA insertion of CP BVD viruses, NADL and Osloss strains, were completely and exactly deleted from the NCP BVD viruses which were real progeny of CP BVD viruses, NADL and Osloss strains. These results suggest that NCP BVD viruses may revert from CP biotype to NCP biotype by the deletion of cellular mRNA insertion in the viral genome of CP BVD viruses (NADL and Osloss strains).
  • AOKI HIROFUMI, SAKODA YOSHIHIRO, TSUCHIYA YOSHINORI, SHOJI IKUO, MATSUURA ZENJI, TAKADA AYAHITO, KIDA HIROSHI, SUGIYAMA KIMIHIRO, FUKUSHO AKIO  日本獣医学会学術集会講演要旨集  123rd-  153  1997/03  [Not refereed][Not invited]
  • SAKODA Yoshihiro  Japanese journal of veterinary research  42-  (1)  33  -33  1994/06/17

Association Memberships

  • THE JAPANESE SOCIETY OF ANIMAL HYGIENE   THE JAPANESE SOCIETY FOR VIROLOGY   JAPANESE SOCIETY OF VETERINARY SCIENCE   

Research Projects

  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2022/04 -2025/03 
    Author : 迫田 義博, 五十嵐 学, 青木 博史
     
    豚熱（CSF）ウイルスおよび非定型豚ペスチ（APP）ウイルスの病原性、特に持続感染を引き起こす分子基盤を解明するために、2つのウイルスが属するフラビウイルス科ペスチウイルス属において病原性因子として細胞の内・外からその機能が発揮できるウイルス構造蛋白質Ernsに着目する。ウイルスがブタに持続感染し、結果として胎子や新生子豚に病原性を発揮するきっかけとなる宿主免疫からの回避と制御された細胞死の抑制に関するErns蛋白質の機能を調べる。 まず、Erns蛋白質の三次元構造と自然免疫の抑制に重要なRNase活性およびⅠ型インターフェロンの産生調節の比較するために、近年国内で分離された中程度の病原性のCSFウイルス野外株、古典的な野外強毒株、およびワクチン株GPE－株のErns遺伝子を真核細胞発現プラスミドにクローニングした。同様に、APPウイルスのErns遺伝子を真核細胞発現プラスミドにクローニングした。これらのプラスミドから発現させた組換えErns蛋白質の自然免疫の抑制に関与するRNase活性とⅠ型インターフェロンの産生抑制能をウイルス株間で比較するための実験系を構築した。またAPPウイルスErns蛋白質の構造を解析し、CSFウイルスのそれと比較してRNase活性ドメインのモチーフに特有の配列があることがわかった。さらに、APPウイルス国内分離株をブタに接種し、臨床症状の観察に加え、ウイルスの生体での検出期間、各臓器における組織病変を確認した。その結果、豚での増殖は非常に限定的であることがわかった。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2022/04 -2025/03 
    Author : 迫田 義博, 五十嵐 学, 青木 博史
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    Date (from‐to) : 2020/04 -2023/03 
    Author : 小原 恭子, 岡林 環樹, 迫田 義博
     
    口蹄疫や豚熱は一度発生すると畜産業に甚大な被害を与える家畜伝染病で、制圧に多国間の協力を要する越境性動物疾病である。これらの原因ウイルスである口蹄疫ウイルス(FMDV)や豚熱ウイルス(CSFV)のゲノム5’端には、長い非翻訳領域(IRES)が存在し、リボゾームが認識してウイルス蛋白質合成を開始する。IRESを標的にして複製を抑制できる事が同属ウイルスで報告されており、IRES遺伝子配列が比較的保存している事からより広いスペクトラムの抗ウイルス作用の標的となる事が期待できる。これまでに、FMDV-IRESやCSFV-IRESを標的としたshRNA発現ベクターを開発し、IRES阻害効果を確認している。このうち、FMDV-IRESのshRNAは、FMDVの7血清型で保存した遺伝子領域を標的としている。また、FMDV-IRESに作用する宿主因子については、IRES活性を阻害するフランス松樹液のピクノジュノール(PYC)を作用した際に発現が変化するものをマイクロアレイで解析し、大きく発現抑制される宿主因子に対してsiRNAを設計してこれら因子の関与を確認した。同時にこれらの因子のうち、CSFV-IRESでも作用する因子をsiRNAで確認した。作用の強いものから、polycystic kidney disease 1-like 3 (PKD1L3)、ubiquitin-specific peptidase 31 (USP31)が同定されている(Ide et al., Sci. Rep., accepted 2022)。今後は、これらの因子の生体におけるIRES制御作用を解明するため、ノックアウトマウスの樹立を実施する予定である。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    Date (from‐to) : 2019/04 -2022/03 
    Author : SAKODA Yoshihiro
     
    The manifestation of the diverse pathogenicity of classical swine fever virus (CSFV) were elucidated from the molecular level of viral proteins to the in vivo level by experimental infection of pigs with mutant viruses. As a result, it was clarified that the novel viral factors involved in pathogenicity of CSFV in pigs. In addition, we found that multiple viral factors identified in this study synergistically contributed to the pathogenicity of CSFV. Furthermore, it was revealed that viruses in the infected pigs are not a single virus population but a quasispecies (mixture), and that the balance of activities of viral factors derived from the major and minor virus populations determines virulence.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2013/04 -2017/03 
    Author : Ishiguro Nobuhisa, SAKODA YOSHIHIRO, KAIHO MIKI
     
    Four anti-neuraminidase inhibitors (laninamivir, oseltamivir, peramivir and zanamivir) are now available for treatment of influenza virus infection. The purpose of this study was clinical evaluations of four anti-neuraminidase inhibitors for treatment of influenza virus infection. We reached the following conclusion; (1) oseltamivir and peramivir had advantages over laninamivir and zanamivir in treating patients (0 to 18 years old) infected with influenza A viruses, (2) laninamivir and zanamivir had advantages over oseltamivir and peramivir in treating patients (0 to 18 years old) infected with influenza B viruses.
  • 日本学術振興会：科学研究費助成事業 基盤研究(B)
    Date (from‐to) : 2013/04 -2014/03 
    Author : 迫田 義博
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(B))
    Date (from‐to) : 2007 -2009 
    Author : Yoshihiro SAKODA, Hiroshi AOKI
     
    To assess the molecular basis of classical swine fever virus, the mechanism of down regulation of innate immunity mediated by type-1 interferon was analyzed using mutant viruses constructed by reverse genetics. Critical amino acids of N^ protein for the control of type-1 interferon production were determined and it was concluded that the down regulation of innate immunity mediated by type-1 interferon was one of the important factors for the pathogenicity of classical swine fever virus in pigs.
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(S))
    Date (from‐to) : 2003 -2006 
    Author : Hiroshi KIDA, 岡崎 克則, 河岡 義裕, 迫田 義博, 梅村 孝司, 伊藤 壽啓, 小笠原 一誠
     
    H5N1 highly pathogenic avian influenza (HPAI) virus has spread in poultry from Southeast Asia to the north, Europe, and Africa. We have been conducting global surveillance of avian influenza and the assessment of pathogenicity of the H5 virus isolates in birds and mammals. In 2006, 55 avirulent avian influenza viruses were isolated from fecal sample of water birds. Thus, avian influenza viruses of 133 combinations of HA and NA subtypes have been stocked for use in vaccine and diagnosis.It was revealed that the H5N1 isolates in Mongolia in 2006 were closely related to each other and classifi...
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(B))
    Date (from‐to) : 2003 -2005 
    Author : Motoshi TAJIMA, 迫田 義博, 落合 謙爾
     
    We examined the relationship between clinical symptoms in persistently infected cattle (PI) with bovine viral diarrhea virus (BVDV) and subgenotypes of the virus isolated from the PI. Subgenotypes were identified based on diversity of nucleotide sequence of BVDV E2 coding region. By the phylogenetic analysis, 13 iolates were classified in 1c subgenotype. Some PI infected with BVDV 1c indicated disorder of central nervous system (CNS) characterized by locomotive abnormalities, and had pathological changes in cerebrum on necropsy. All BVDV infected from PI complicated diabetes mellitus (DM) w...
  • 文部科学省：科学研究費補助金(若手研究(B))
    Date (from‐to) : 2003 -2004 
    Author : 迫田 義博
     
    牛ウイルス性下痢ウイルス(BVDV)に感染した牛が致死的な粘膜病を発病する際には、ウイルス遺伝子内に宿主由来遺伝子が挿入することが明らかになっている。この宿主遺伝子の一つとしてcINS遺伝子がある。このcINS遺伝子から翻訳される蛋白は分子シャペロンとして機能し、BVDVの病原性発揮に関与していると考えられるが、詳細は不明である。本年度は、昨年作出した組換えcINS蛋白に対するモノクローン抗体、およびNS2-3蛋白発現プラスミドを用いて、cINS蛋白がNS2-3蛋白の開裂に直接作用するのかを明らかにするとともに、分子シャペロンであるcINS蛋白と相互作用すると考えられる新たな宿主因子をTwo Hybridシステムで検索した。その結果、cINS蛋白とNS2-3は直接結合することがわかった。しかし、NS2-3の開裂には宿主由来の蛋白が2つ必須であることが明らかになった。現在これらの宿主因子の機能解析を詳細に行っている。また、作製されたモノクローン抗体を利用して、cINS遺伝子がウイルスゲノムに取り込まれているウイルス株を野外ウイルス株から選択し、Nose株の病原性獲得メカニズムとの比較を行った。その結果、野外にはNose株と同様の病原性獲得メカニズムによって病原性を獲得したと思われるウイルスが1株確認された。さらに、BVDVと同じペスチウイルスに属する豚コレラウイルスの新たな細胞...
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(B))
    Date (from‐to) : 2001 -2003 
    Author : Motoshi TAJIMA, 山崎 真大, 大和 修, 迫田 義博
     
    Based on E2 coding gene of bovine viral diarrhea virus (BVDV), phylogenetic analyzes were performed using BVDV field isolates from Japan, Germany and the United States of America (USA). Almost German field isolates were classified as 1b and 1d subgenotypes. Subgenotype 1d was considered as characteristic subgenotype of BVDV distributed in Germany. In the USA, 37.5% of field isolates were classified as BVDV2, and those were subdivided into 2a and 2c subgenotypes. The remaining isolates were identified as BVDV1 and almost of them were classified as 1b. Japanese, German and American 1b constru...
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(A))
    Date (from‐to) : 2000 -2002 
    Author : Hiroshi KIDA, 高田 礼人, 河岡 義裕, 岡崎 克則, 伊藤 壽啓, 迫田 義博
     
    To provide information on the precursor genes of the next pandemic influenza, epidemiological surveillance of animal and avian influenza viruses was performed. In total, 3,987 fecal samples of migratory waterfowls were collected in Russia, Mongolia, China and Holdcaido, Japan. From these samples, 212 influenza A viruses were isolated H1N2 swine influenza viruses were isolated from pigs with respiratory syndrome in Miyagi Prefecture, Japan. Twenty-five strains of H9N2 viruses were exchanged between 5 centers of global animal influenza network and stated analyzing these viruses.Genetic analys...
  • ウイルス病の予防に関する研究
  • Study on prophylaxis of viral disease

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