Researcher basic information

• 博士（獣医学）, 岐阜大学大学院, Mar. 2019

• https://researchmap.jp/y_ohari?lang=en

• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201901013417207236

• 201901013417207236

• Trematode
• Population genetics
• Parasitology

• Life Science, Ecology and environment
• Life Science, Parasitology
• Life Science, Biodiversity and systematics

• Doctoral (PhD) degree program, Graduate School of Infectious Diseases

Research activity information

• May 2020, 日本獣医寄生虫学会, 第11回日本獣医寄生虫学奨励賞
• Sep. 2018, Japanese Society of Parasitology, ICOPA 2018 Travel Award.
  Genetic structure of Fasciola population in Japan based on microsatellite DNA markers.
  Yuma OHARI

• Genomic signatures of native (Japanese) and introduced (Oceanian) populations of the Asian longhorned tick Haemaphysalis longicornis.
  Yuma Ohari; Kodai Kusakisako; Mackenzie L Kwak; Rika Umemiya-Shirafuji; Wessam Mohamed Ahmed Mohamed; Mohamed Abdallah Mohamed Moustafa; Elisha Chatanga; Samuel Kelava; Ketan Christi; Dinesh Kumar; Nariaki Nonaka; Yasuko Orba; Keita Matsuno; Ryo Nakao
  PNAS nexus, 5, 8, pgag232, Aug. 2026, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal, The Asian longhorned tick (Haemaphysalis longicornis) impacts the health of humans, livestock, and wildlife, both as a parasite and a vector. Over more than a century, H. longicornis has become a widespread invasive species across much of the Asia-Pacific region, with a recent emergence in North America. This dispersal success could be associated with the ability of certain lineages of H. longicornis to reproduce via parthenogenesis. We analyzed complete mitochondrial genomes and genome-wide single-nucleotide polymorphisms (SNPs) from ticks collected within the native range of H. longicornis (Japan), invasive populations in the Asia-Pacific (Australia, Fiji, and New Caledonia), and laboratory-maintained parthenogenetic and bisexual strains. We also compared our data with DNA sequences in GenBank from invasive populations in other countries (e.g., United States). Two distinct clades (Mt-Clade 1 and Mt-Clade 2) were observed in the phylogenetic tree based on mitochondrial genomes. All specimens from the bisexual laboratory strains were assigned to Mt-Clade 1 and those from the parthenogenetic laboratory strains were assigned to Mt-Clade 2, whereas the field-collected male specimens were included in both clades. No geographical cline associated with the phylogenetic characteristics was observed. In contrast, analyses based on genome-wide SNPs demonstrated a cluster composed of Oceanian samples apart from Japanese samples and detected gene flow between the two mitogenomic clades. Our results suggest that parthenogenesis may have evolved multiple times within H. longicornis rather than originating from a single evolutionary event.
• Population genetic evidence of heterogeneous zoonotic transmission of Schistosoma japonicum in endemic communities in the Philippines.
  Sirin Kunluang; Yuma Ohari; Atcharaphan Wanlop; Maria Angenica F Regilme; Adrian Miki C Macalanda; Jose Ma M Angeles; Katrina Theresa M Balboa; Kristina Maria R Petalcorin; Elena A Villacorte; Pilarita Tongol-Rivera; Keisuke Suganuma; Noboru Inoue; Shin-Ichiro Kawazu
  Tropical medicine and health, 54, 1, 19 Jul. 2026, [Domestic magazines]
  English, Scientific journal, BACKGROUND: Zoonotic schistosomiasis, which is caused by the parasite Schistosoma japonicum, remains a neglected public health concern in Asian countries, including China, the Philippines, and Indonesia. The presence of animal reservoirs poses a significant challenge to controlling the disease. Previous studies in China have found that incorporating measures to control animal reservoirs led to a reduction in human cases. To support control efforts in the Philippines, we conducted a multi-locus genotyping (MLG) analysis using microsatellite markers (STRs) to investigate the transmission dynamics of S. japonicum infections between human and animal hosts in two moderately endemic areas. METHODS: Stool and faecal samples were collected from human residents and water buffaloes in the provinces of Leyte and Oriental Mindoro. S. japonicum eggs were isolated from positive samples and single-egg genome DNA was extracted for STR/MLG analysis. RESULTS: STRUCTURE analysis and discriminant analysis of principal components (DAPC) in Leyte showed that the parasite populations in water buffaloes clustered with that in humans, suggesting potential zoonotic transmission. By contrast, STRUCTURE and DAPC analyses revealed distinct parasite populations in water buffaloes and humans in Oriental Mindoro, suggesting limited genetic overlap between parasite populations in humans and water buffaloes in this study area, which may indicate reduced contribution of buffaloes to transmission under the conditions studied. CONCLUSIONS: Overall, these findings highlight the need to include animal surveillance in guidelines for schistosomiasis elimination. Given the complex life cycle of the parasite, it is crucial to understand infection dynamics across human and animal hosts when designing effective, integrated control strategies.
• Epidemiological, clinical, and virological characterizations of Yezo virus infections, an emerging tick-borne orthonairovirus disease in Japan.
  Hiroki Yamaguchi; Keita Mizuma; Kei Watari; Yuma Ohari; Kazuya Mitsuhashi; Kazuma Tamiya; Nijiho Kawaguchi; Yasuko Orba; Masayuki Saijo; Keita Matsuno
  The Journal of infectious diseases, 10 Feb. 2026, [Peer-reviewed], [International Magazine]
  English, Scientific journal, BACKGROUND: Febrile disease caused by infections of Yezo virus (YEZV), a tick-borne orthonairovirus, was first reported in Japan in 2021 and subsequently identified in China. While the recent studies suggest a broader endemic area of the emerging YEZV infections, its clinical and epidemiological characteristics remain poorly elucidated due to the limited number of reported cases. METHODS: We conducted retrospective and prospective surveillance of patients with suspected tick-borne febrile illnesses in Hokkaido, Japan, between 2013 and 2024. Serum samples were analyzed by RT-qPCR, IgM/IgG ELISA, and neutralization assay. Viral genome of isolates was sequenced and phylogenetically analyzed with publicly available YEZV genomes. RESULTS: A total of 22 patients with YEZV infections including 10 newly identified patients was analyzed. Most infections occurred between May and July, coinciding with the peak activity of Ixodes ticks in the study area. A case from southern Hokkaido was firstly identified. Fever, leukocytopenia, thrombocytopenia, elevated levels of liver enzymes, and ferritin were determined as common features observed in patients with YEZV infections. Viral RNA was typically detectable in the serum within 7 days after the disease onset. Serum antibodies became positive later and might persist up to at least 600 days. Phylogenetic analysis incorporating five new isolates showed the circulations of two genetic groups of YEZVs in Japan. CONCLUSIONS: Our results revealed characteristics of YEZV infections in patients and highlighted the importance of combination of molecular and serological diagnostics. The proposed case definitions and diagnostic framework may contribute future surveillance.
• Spatial distribution of ticks and tick-borne pathogens in central Hokkaido, Japan and associated ecological factors revealed by intensive short-term survey in 2024
  Mebuki Ito; Yuma Ohari; Mai Kishimoto; Keita Matsuno
  openRxiv, 06 Feb. 2026
  Tick-borne pathogens are transmitted by tick bites to cause infectious diseases in humans and domestic animals. To anticipate the occurrence of tick-borne diseases, it is required to understand high resolution distribution of infection risk and associated ecological factors. The aim of the present study is to reveal the spatial distribution of ticks and ticks infected with pathogens in central Hokkaido, Japan. Adult and nymphal ticks were collected with a constant effort at 171 sites from 13 May to 26 June 2024, followed by screening tick-borne pathogens. The potential suitable habitats of seven tick species and the endemic tick-borne pathogens in the study area (i.e. tick-borne encephalitis virus, Yezo virus, Beiji nairovirus, Lyme disease group borreliae, and relapsing fever group borreliae) were predicted using ecological niche modeling. Ixodes persulcatus and Ixodes ovatus were identified as the primary ticks to determine the distributions of all the pathogens. Besides, the predicted suitable habitats were specific to each pathogen/tick species. Among the environmental variables considered for modeling, snow depth appeared to significantly contribute to the distribution differences between ticks and pathogens. The findings of this study expand our understanding of the spatial risk distribution of tick-borne pathogen infections and its ecological context.
• Molecular and Functional Characterization of Sika Deer ACE2 as a Receptor for SARS-CoV-2.
  Anastasiia Kovba; Manabu Igarashi; Keita Mizuma; Yuma Ohari; Manabu Onuma; Michito Shimozuru; Kotaro Shimizu; Masami Yamanaka; Keita Matsuno; Toshio Tsubota
  Microbiology and immunology, 69, 11, 533, 543, Nov. 2025, [International Magazine]
  English, Scientific journal, Surveillance of SARS-CoV-2 in white-tailed deer (WTD, Odocoileus virginianus) has revealed its widespread and sustained transmission across North America, with evidence suggesting possible transmission from deer to humans. In the following surveillance studies in other deer species, however, little evidence of infection spread was found, including in sika deer (Cervus nippon) in our previous study. Differences in the structure of the virus entry receptor angiotensin-converting enzyme 2 (ACE2) are known to act as one of the functional barriers to SARS-CoV-2 infection. To investigate the molecular basis of the lack of SARS-CoV-2 transmission to sika deer, we performed structural and functional analyses of the sika deer ACE2 in comparison with WTD ACE2. Comparison of sika deer ACE2 sequence and those of cervid species with WTD ACE2, followed by in silico molecular dynamics analysis, revealed a substitution of lysine to asparagine in position 31 commonly found in cervid ACE2s can potentially alter binding to the SARS-CoV-2 spike (S) protein receptor-binding domain (RBD). Functional assays in cells expressing sika deer and WTD ACE2s showed minimal differences in viral binding and replication, demonstrating that SARS-CoV-2 can similarly utilize ACE2 from both species. These findings suggest that sika deer and possibly other cervids may be highly susceptible to SARS-CoV-2 and highlight the need to investigate other factors impacting virus spread in deer populations.
• Mitogenomics of the tropical bont tick Amblyomma variegatum reveals vertical and horizontal transmission of Rickettsia africae.
  Elisha Chatanga; Wessam Mohamed Ahmed Mohamed; Samuel Kelava; Naoki Hayashi; Yuma Ohari; Mohamed Abdallah Mohamed Moustafa; Joseph W Magona; Kyoko Hayashida; Yongjin Qiu; Nariaki Nonaka; Ryo Nakao
  PLoS neglected tropical diseases, 19, 10, e0013610, Oct. 2025, [International Magazine]
  English, Scientific journal, BACKGROUND: The tropical bont tick Amblyomma variegatum, which is widespread in Africa and the Caribbean islands, is of both medical and veterinary importance as the principal vector of intracellular bacterial pathogens Ehrlichia ruminantium, causing heartwater in animals, and Rickettsia africae, causing African tick bite fever (ATBF) in humans. This tick species is highly invasive and has been reported to expand its geographical distribution as well as host range. Rickettsia africae is also recognized as a common endosymbiont in A. variegatum, but its transmission dynamics within this tick population remain poorly understood. METHODOLOGY: To investigate the co-phylogenetic patterns between A. variegatum and R. africae, we sequenced the complete mitogenomes of A. variegatum and performed multi-locus sequence typing (MLST) of six housekeeping genes of R. africae. The resulting sequence data were used to examine the hypothesis that R. africae is predominantly transmitted vertically within A. variegatum populations, which would lead to congruent phylogenies between vector and pathogen. RESULTS: There was geographical population sub-structuring in the mitogenomes of A. variegatum. The prevalence of R. africae in the examined ticks was 100%. The tanglegram showed non-strict co-cladogenesis between A. variegatum and R. africae. Furthermore, the Procrustes Application to Cophylogenetic (PACo) analysis and residuals of vector-pathogen associations showed no statistically significant association between A. variegatum and R. africae genotypes. CONCLUSIONS: This study was the first to examine the spread of pathogenic/endosymbiotic bacterium R. africae in the A. variegatum populations using a mitogenomic approach. The results support both vertical and horizontal transmission of R. africae within A. variegatum. These findings also highlight the potential of R. africae to adapt to multiple animal species, which may complicate efforts to control it as a human pathogen.
• A temporal analysis of horse fly prevalence in Tokachi, Hokkaido, Japan, based on a 3-year entomological survey
  Keisuke Suganuma; Yuta Okuno; Mitsunori Kayano; Tomas J. Acosta; Takeo Yamauchi; Adrian Miki C. Macalanda; Maria Angenica F. Regilme; Frances Paula L. Miaral; Yrjo T. Grohn; Yuma Ohari; Shin-ichiro Kawazu; Noboru Inoue
  JOURNAL OF MEDICAL ENTOMOLOGY, 24 Sep. 2025
  English, Scientific journal
• Distribution and population genetic analysis of lymnaeid snails in Aomori prefecture, Japan.
  Yuichi Kamiharako; Kazuhiko Nakayama; Yuta Takayama; Yuma Ohari; Sakure Nakamura; Jun Hakozaki; Asako Haraguchi; Naoki Nakanome; Nursehang Tamodding; Isra Wahid; Kodai Kusakisako; Hiromi Ikadai
  The Journal of veterinary medical science, 87, 9, 990, 994, 01 Sep. 2025, [Domestic magazines]
  English, Scientific journal, Fasciolosis, a parasitic disease caused by Fasciola flukes, leads to economic losses in livestock. These flukes require freshwater snails, such as the genera Orientogalba and Galba as intermediate hosts, made snail distribution monitoring essential for disease surveillance and prevention. A survey conducted in Aomori prefecture from spring 2022 to summer 2023 identified Orientogalba snails and Galba snails in 49 rice paddies. Molecular analysis of 233 cytochrome c oxidase subunit 1 partial sequences classified Orientogalba into O. hokkaidoensis and O. ollula. Orientogalba hokkaidoensis was widely distributed across Aomori prefecture. Most Galba snails were identified as Galba pacifica. Additionally, some Lymnaea schirazensis-like snails were detected. These findings provide fundamental data on freshwater snails in Aomori, aiding fasciolosis control.
• Phylogenetic position of the northern pika Ochotona hyperborea in Hokkaido, Japan based on mitochondrial COI sequences
  Tomoki Sakiyama; Shumpei Kamiyama; Kuniko Kawai; Yuma Ohari; Keita Matsuno; Satoshi D. Ohdachi
  MAMMAL RESEARCH, 70, 3, 399, 405, Jul. 2025
  English, Scientific journal
• Comprehensive mitochondrial genomics of Fasciola gigantica from Sudan: insights into genetic diversity, evolutionary dynamics, and host adaptation
  Bashir Salim; Nouh S. Mohamed; Kamal Ibrahim; Saeed Alasmari; Elisha Chatanga; Yuma Ohari; Nariaki Nonaka; Mohammad A. Alsaad; Faisal Almathen; Ryo Nakao
  FRONTIERS IN VETERINARY SCIENCE, 12, 01 May 2025
  English, Scientific journal
• Phylogenetic characterization of the pork tapeworm Taenia solium in Japan: implications for the enigmatic evolutionary history
  Naoki Hayashi; Ryo Kuwamoto; Mitsuhiro Okada; Kenta Suzuki; Takaya Hoketsu; Samuel Kelava; Yuma Ohari; Munehiro Okamoto; Kinpei Yagi; Nariaki Nonaka; Ryo Nakao
  International Journal for Parasitology, Elsevier BV, Apr. 2025
  Scientific journal
• Characterization of 23 SNP markers for the chum salmon (Oncorhynchus keta) based on multiplex ISSR genotyping by sequencing (MIG-seq)
  Hideharu Tsukagoshi; Yuma Ohari
  CONSERVATION GENETICS RESOURCES, 17, 1, 79, 82, Mar. 2025
  English, Scientific journal
• Intra-individual polymorphisms in the mitochondrial COI gene of tick-killing Ixodiphagus wasps parasitizing Haemaphysalis flava ticks.
  Yurie Taya; Yuto Shiraki; Samuel Kelava; Naoki Fujisawa; Yuma Ohari; Mackenzie L Kwak; Saori Baba; Hideka Numata; Gita Sadaula Pandey; Yuki Ohsugi; Yuki Katada; Shiho Niwa; Shohei Ogata; Keita Matsuno; Nariaki Nonaka; Ryo Nakao
  Acta tropica, 107510, 107510, 16 Dec. 2024, [International Magazine]
  English, Scientific journal, Ixodid ticks are significant vectors of pathogens affecting both humans and animals. Biological control with natural enemies represents a sustainable tool for managing ticks. However, there is a substantial lack of knowledge about the natural enemies of ticks. Wasps of the genus Ixodiphagus (Encyrtidae) are currently the only known tick-specific parasitoids. While these wasps have been sporadically recorded worldwide, their presence in Eastern Asia is poorly documented. In this study, we investigated the occurrence of Ixodiphagus wasps in field-collected ticks reared on rabbits under laboratory conditions. Ticks were collected from the Hokkaido, Hokuriku, Chugoku, Shikoku, and Kyushu regions in Japan. Out of 1,933 Haemaphysalis ticks attached to rabbits, adult wasps emerged from 15 engorged ticks. All the ticks from which wasps emerged were morphologically and molecularly identified as Haemaphysalis flava. Additionally, wasp DNA was detected in unfed H. flava nymphs using a newly designed Ixodiphagus-specific PCR assay. Among nine experimental sites in the Chugoku region, Ixodiphagus wasps were detected at three sites, with parasitism rates ranging from 1.8% to 8.1%. Finally, the mitochondrial COI genes of four wasp and two tick samples were characterized using shotgun sequencing, direct sequencing and in-fusion cloning approaches. Multiple intra-individual polymorphisms were observed in all the tested samples. Further studies are needed to investigate the relationship between Ixodiphagus wasps and Ixodid ticks. An increased understanding of these parasitoid wasps could contribute to future biological control measures against ticks.
• Environmental and host factors underlying tick-borne virus infection in wild animals: Investigation of the emerging Yezo virus in Hokkaido, Japan
  Mebuki Ito; Miku Minamikawa; Anastasiia Kovba; Hideka Numata; Tetsuji Itoh; Takuma Ariizumi; Asako Shigeno; Yuki Katada; Shiho Niwa; Yurie Taya; Yuto Shiraki; Gita Sadaula Pandey; Nariaki Nonaka; Ryo Nakao; Ryosuke Omori; Yuma Ohari; Norikazu Isoda; Michito Shimozuru; Toshio Tsubota; Keita Matsuno; Mariko Sashika
  Ticks and Tick-borne Diseases, 15, 6, 102419, 102419, Elsevier BV, Nov. 2024
  Scientific journal
• Environmental and host factors underlying tick infestation in invasive raccoons (Procyon lotor) in Hokkaido, Japan
  Mebuki Ito; Miku Minamikawa; Anastasiia Kovba; Hideka Numata; Tetsuji Itoh; Yuki Katada; Shiho Niwa; Yurie Taya; Yuto Shiraki; Gita Sadaula Pandey; Samuel Kelava; Nariaki Nonaka; Ryo Nakao; Ryosuke Omori; Yuma Ohari; Norikazu Isoda; Michito Shimozuru; Toshio Tsubota; Keita Matsuno; Mariko Sashika
  Ticks and Tick-borne Diseases, 15, 6, 102389, 102389, Elsevier BV, Nov. 2024
  Scientific journal
• Molecular and structural insights into SARS-CoV-2 evolution: from BA.2 to XBB subvariants
  Hisano Yajima; Tomo Nomai; Kaho Okumura; Katsumi Maenaka; Jumpei Ito; Takao Hashiguchi; Kei Sato; Keita Matsuno; Naganori Nao; Hirofumi Sawa; Keita Mizuma; Jingshu Li; Izumi Kida; Yume Mimura; Yuma Ohari; Shinya Tanaka; Masumi Tsuda; Lei Wang; Yoshikata Oda; Zannatul Ferdous; Kenji Shishido; Hiromi Mohri; Miki Iida; Takasuke Fukuhara; Tomokazu Tamura; Rigel Suzuki; Saori Suzuki; Shuhei Tsujino; Hayato Ito; Yu Kaku; Naoko Misawa; Arnon Plianchaisuk; Ziyi Guo; Alfredo A. Hinay; Kaoru Usui; Wilaiporn Saikruang; Spyridon Lytras; Keiya Uriu; Ryo Yoshimura; Shusuke Kawakubo; Luca Nishumura; Yusuke Kosugi; Shigeru Fujita; Jarel Elgin M.Tolentino; Luo Chen; Lin Pan; Wenye Li; Maximilian Stanley Yo; Kio Horinaka; Mai Suganami; Mika Chiba; Kyoko Yasuda; Keiko Iida; Adam Patrick Strange; Naomi Ohsumi; Shiho Tanaka; Eiko Ogawa; Tsuki Fukuda; Rina Osujo; Kazuhisa Yoshimura; Kenji Sadamas; Mami Nagashima; Hiroyuki Asakura; Isao Yoshida; So Nakagawa; Kazuo Takayama; Rina Hashimoto; Sayaka Deguchi; Yukio Watanabe; Yoshitaka Nakata; Hiroki Futatsusako; Ayaka Sakamoto; Naoko Yasuhara; Tateki Suzuki; Kanako Kimura; Jiei Sasaki; Yukari Nakajima; Takashi Irie; Ryoko Kawabata; Kaori Sasaki-Tabata; Terumasa Ikeda; Hesham Nasser; Ryo Shimizu; Mst Monira Begum; Michael Jonathan; Yuka Mugita; Sharee Leong; Otowa Takahashi; Takamasa Ueno; Chihiro Motozono; Mako Toyoda; Akatsuki Saito; Anon Kosaka; Miki Kawano; Natsumi Matsubara; Tomoko Nishiuchi; Jiri Zahradnik; Prokopios Andrikopoulos; Miguel Padilla-Blanco; Aditi Konar
  mBio, 15, 10, American Society for Microbiology, 16 Oct. 2024
  Scientific journal, ABSTRACT
  
  Due to the incessant emergence of various SARS-CoV-2 variants with enhanced fitness in the human population, controlling the COVID-19 pandemic has been challenging. Understanding how the virus enhances its fitness during a pandemic could offer valuable insights for more effective control of viral epidemics. In this manuscript, we review the evolution of SARS-CoV-2 from early 2022 to the end of 2023—from Omicron BA.2 to XBB descendants. Focusing on viral evolution during this period, we provide concrete examples that SARS-CoV-2 has increased its fitness by enhancing several functions of the spike (S) protein, including its binding affinity to the ACE2 receptor and its ability to evade humoral immunity. Furthermore, we explore how specific mutations modify these functions of the S protein through structural alterations. This review provides evolutionary, molecular, and structural insights into how SARS-CoV-2 has increased its fitness and repeatedly caused epidemic surges during the pandemic.
• Structural basis for receptor-binding domain mobility of the spike in SARS-CoV-2 BA.2.86 and JN.1
  Hisano Yajima; Yuki Anraku; Yu Kaku; Kanako Terakado Kimura; Arnon Plianchaisuk; Kaho Okumura; Yoshiko Nakada-Nakura; Yusuke Atarashi; Takuya Hemmi; Daisuke Kuroda; Yoshimasa Takahashi; Shunsuke Kita; Jiei Sasaki; Hiromi Sumita; Keita Matsuno; Naganori Nao; Hirofumi Sawa; Keita Mizuma; Jingshu Li; Izumi Kida; Yume Mimura; Yuma Ohari; Shinya Tanaka; Masumi Tsuda; Lei Wang; Yoshikata Oda; Zannatul Ferdous; Kenji Shishido; Hiromi Mohri; Miki Iida; Takasuke Fukuhara; Tomokazu Tamura; Rigel Suzuki; Saori Suzuki; Shuhei Tsujino; Hayato Ito; Naoko Misawa; Ziyi Guo; Alfredo A. Hinay; Kaoru Usui; Wilaiporn Saikruang; Spyridon Lytras; Keiya Uriu; Ryo Yoshimura; Shusuke Kawakubo; Luca Nishumura; Yusuke Kosugi; Shigeru Fujita; Jarel Elgin M.Tolentino; Luo Chen; Lin Pan; Wenye Li; Maximilian Stanley Yo; Kio Horinaka; Mai Suganami; Mika Chiba; Kyoko Yasuda; Keiko Iida; Adam Patrick Strange; Naomi Ohsumi; Shiho Tanaka; Eiko Ogawa; Tsuki Fukuda; Rina Osujo; Kazuhisa Yoshimura; Kenji Sadamas; Mami Nagashima; Hiroyuki Asakura; Isao Yoshida; So Nakagawa; Kazuo Takayama; Rina Hashimoto; Sayaka Deguchi; Yukio Watanabe; Yoshitaka Nakata; Hiroki Futatsusako; Ayaka Sakamoto; Naoko Yasuhara; Tateki Suzuki; Yukari Nakajima; Takashi Irie; Ryoko Kawabata; Kaori Sasaki-Tabata; Terumasa Ikeda; Hesham Nasser; Ryo Shimizu; M. S. T. Monira Begum; Michael Jonathan; Yuka Mugita; Sharee Leong; Otowa Takahashi; Takamasa Ueno; Chihiro Motozono; Mako Toyoda; Akatsuki Saito; Anon Kosaka; Miki Kawano; Natsumi Matsubara; Tomoko Nishiuchi; Jiri Zahradnik; Prokopios Andrikopoulos; Miguel Padilla-Blanco; Aditi Konar; Jumpei Ito; Katsumi Maenaka; Kei Sato; Takao Hashiguchi
  Nature Communications, 15, 1, Springer Science and Business Media LLC, 07 Oct. 2024
  Scientific journal
• Taxonomy and trans-Beringian biogeography of the pond snails (Gastropoda: Lymnaeidae) of East Asia: an integrative view
  Olga V Aksenova; Maxim V Vinarski; Tadashi Itagaki; Yuma Ohari; Tatsuo Oshida; Sang Ki Kim; Jin Hee Lee; Alexander V Kondakov; Irina S Khrebtova; Alena A Soboleva; Oksana V Travina; Svetlana E Sokolova; Dmitry M Palatov; Yulia V Bespalaya; Ilya V Vikhrev; Mikhail Yu Gofarov; Ivan N Bolotov
  Zoological Journal of the Linnean Society, 201, 4, Oxford University Press (OUP), 01 Aug. 2024
  Scientific journal, Abstract
  
  In this work, we present an integrative revision of the Lymnaeidae from the northeastern margin of Asia (Far East Russia, Japan, and Korea) and Alaska. According to our results, 14 native species inhabit this region, belonging to eight genera in two subfamilies (Lymnaeinae: Dallirhytis, Galba, Walhiana, Ladislavella, and Lymnaea; and Amphipepleinae: Kamtschaticana, Orientogalba, and Radix). Four of these species are new to science and three of them are described in this paper. Additionally, three established alien species are recorded from Japan (Pseudosuccinea columella, Galba schirazensis, and Galba humilis). The Japanese Archipelago represents an evolutionary hotspot of pond snail diversity, encompassing seven native species, three of which are endemic. The faunal connections between North America and northeastern Asia are discussed in the context of historical biotic interchange across the Beringian Land Bridge. Two cold-tolerant pond snails share high-latitude but localized ranges, being endemic to the Beringian Arctic: Dallirhytis atkaensis (Chukchi Peninsula, Alaska, and Aleutian Islands) and Walhiana arctica comb. nov. (Alaska). Our findings indicate that the Beringian Land Bridge has played a role in freshwater faunal exchanges between northeastern Asia and western North America.
• Expression profile analysis of the transient receptor potential (TRPM) channel, a possible target of praziquantel in Schistosoma japonicum.
  Kaho Shinozaki; Masashi Kirinoki; Wanlop Atcharaphan; Ken-Ichi Watanabe; Yuma Ohari; Saki Suguta; Kevin Austin L Ona; Nanako Ushio; Adrian Miki C Macalanda; Keisuke Suganuma; Noboru Inoue; Shin-Ichiro Kawazu
  Parasitology international, 99, 102833, 102833, Apr. 2024, [International Magazine]
  English, Scientific journal, The WHO considers schistosomiasis, which is controlled by the mass administration of the drug praziquantel (PZQ), to be a neglected tropical disease. Despite its clinical use for over four decades, PZQ remains the only choice of chemotherapy against this disease. Regarding the previous studies that demonstrated that PZQ activates the transient receptor potential (TRP) channel in Schistosoma mansoni (Sm.TRPMPZQ), the expression profile of the ortholog of this channel gene (Smp_246790.5) in S. japonicum (EWB00_008853) (Sj.TRPMPZQ) was analyzed. The relative expression of this gene in various stages of the parasite lifecycle was analyzed by quantitative real-time reverse transcription-PCR (qRT-PCR), and the expression of Sj.TRPMPZQ was observed by immunohistochemical staining using anti-serum against the recombinant Sj.TRPMPZQ protein. qRT-PCR revealed the significantly lower mRNA expression in the snail stage in comparison to other stages (p < 0.01). The relative quantity of the Sj.TRPMPZQ expression for paired females, unpaired males, and eggs was 60%, 56%, and 68%, respectively, in comparison to paired males that showed the highest expression (p < 0.05). Interestingly, immunostaining demonstrated that Sj.TRPMPZQ is expressed in the parenchyma which contains muscle cells, neuronal cells and tegument cells in adult worms. This may support the two major effects of PZQ-worm paralysis and tegument disruption-induced by channel activation. Moreover, the channel was expressed in both the eggshell and the miracidia inside, but could not be observed in sporocyst. These results suggest that the expression of Sj.TRPMPQZ corresponds to the known sensitivity of S. japonicum to PZQ.
• Far-East Asian Toxoplasma isolates share ancestry with North and South/Central American recombinant lineages
  Ihara, F.; Kyan, H.; Takashima, Y.; Ono, F.; Hayashi, K.; Matsuo, T.; Igarashi, M.; Nishikawa, Y.; Hikosaka, K.; Sakamoto, H.; Nakamura, S.; Motooka, D.; Yamauchi, K.; Ichikawa-Seki, M.; Fukumoto, S.; Sasaki, M.; Ikadai, H.; Kusakisako, K.; Ohari, Y.; Yoshida, A.; Sasai, M.; Grigg, M.E.; Yamamoto, M.
  Nature Communications, 15, 1, 2024
  Scientific journal
• Investigation of vertical and horizontal transmission of Spiroplasma in ticks under laboratory conditions
  Shohei Ogata; Rika Umemiya-Shirafuji; Kodai Kusakisako; Keita Kakisaka; Elisha Chatanga; Naoki Hayashi; Yurie Taya; Yuma Ohari; Gita Sadaula Pandey; Abdelbaset Eweda Abdelbaset; Yongjin Qiu; Keita Matsuno; Nariaki Nonaka; Ryo Nakao
  Scientific Reports, 13, 1, Springer Science and Business Media LLC, 15 Aug. 2023, [Peer-reviewed]
  Scientific journal, Abstract
  
  Many arthropods harbour bacterial symbionts, which are maintained by vertical and/or horizontal transmission. Spiroplasma is one of the most well-known symbionts of ticks and other arthropods. It is still unclear how Spiroplasma infections have spread in tick populations despite its high prevalence in some tick species. In this study, Ixodes ovatus, which has been reported to harbour Spiroplasma ixodetis at high frequencies, was examined for its vertical transmission potential under experimental conditions. Next, two isolates of tick-derived Spiroplasma, S. ixodetis and Spiroplasma mirum, were experimentally inoculated into Spiroplasma-free Haemaphysalis longicornis colonies and the presence of Spiroplasma in their eggs and larvae was tested. Our experimental data confirmed that S. ixodetis was transmitted to eggs and larvae in a vertical manner in the original host I. ovatus. In the second experiment, there was no significant difference in engorged weight, egg weight, and hatching rate between Spiroplasma-inoculated and control H. longicornis groups. This suggested that Spiroplasma infection does not affect tick reproduction. Spiroplasma DNA was only detected in the eggs and larvae derived from some individuals of S. ixodetis-inoculated groups. This has demonstrated the potential of horizontal transmission between different tick species. These findings may help understand the transmission dynamics of Spiroplasma in nature and its adaptation mechanism to host arthropod species.
• Mitogenomic exploration supports the historical hypothesis of anthropogenic diffusion of a zoonotic parasite Echinococcus multilocularis
  Naoki Hayashi; Ryo Nakao; Yuma Ohari; Takao Irie; Hirokazu Kouguchi; Elisha Chatanga; Wessam Mohamed Ahmed Mohamed; Mohamed Abdallah Mohamed Moustafa; Gohta Kinoshita; Munehiro Okamoto; Kinpei Yagi; Nariaki Nonaka
  iScience, 107741, 107741, Elsevier BV, Aug. 2023, [Peer-reviewed]
  Scientific journal
• Seasonal Variation and Factors Affecting Trypanosoma theileri Infection in Wild Sika Deer (Ezo Sika Deer Cervus nippon yesoensis) in Eastern Hokkaido
  Yujon Hong; Keisuke Suganuma; Yuma Ohari; Mitsunori Kayano; Kenji Nakazaki; Shinya Fukumoto; Shin-ichiro Kawazu; Noboru Inoue
  Animals, 13, 10, 1707, 1707, MDPI AG, 22 May 2023, [Peer-reviewed]
  Scientific journal, Trypanosoma (Megatrypanum) spp. are isolated from domestic and wild ruminants, including deer, worldwide. The prevalence of trypanosomes in mammals is influenced by a number of factors such as host age and vector abundance. However, the seasonal variation of and factors affecting trypanosome infection in the wild deer population remain elusive. In this study, we analyzed the seasonal variation in trypanosome prevalence and the factors that affect Trypanosoma theileri Laveran, 1902, infection in wild sika deer (Ezo sika deer) Cervus nippon yesoensis (Heude, 1884) in Eastern Hokkaido through a two-year survey. Seasonal variation in the prevalence of trypanosome infection in the deer population ranged from 0 to 41% as per hematocrit concentration and 17 to 89% as per PCR results. In general, the prevalence of T. theileri by PCR in 2020 was higher than that in 2019. Moreover, the prevalence was significantly higher in the aged population than among the younger population. These findings may explain why individual conditions and sampling season were associated with trypanosome prevalence. This is the first study to investigate the seasonal variation in and risk factors affecting trypanosome infection in wild deer.
• Cloning, Expression and Evaluation of Thioredoxin Peroxidase-1 Antigen for the Serological Diagnosis of Schistosoma mekongi Human Infection.
  Atcharaphan Wanlop; Jose Ma M Angeles; Adrian Miki C Macalanda; Masashi Kirinoki; Yuma Ohari; Aya Yajima; Junya Yamagishi; Kevin Austin L Ona; Shin-Ichiro Kawazu
  Diagnostics (Basel, Switzerland), 12, 12, 07 Dec. 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Schistosoma mekongi, a blood fluke that causes Asian zoonotic schistosomiasis, is distributed in communities along the Mekong River in Cambodia and Lao People's Democratic Republic. Decades of employing numerous control measures including mass drug administration using praziquantel have resulted in a decline in the prevalence of schistosomiasis mekongi. This, however, led to a decrease in sensitivity of Kato-Katz stool microscopy considered as the gold standard in diagnosis. In order to develop a serological assay with high sensitivity and specificity which can replace Kato-Katz, recombinant S. mekongi thioredoxin peroxidase-1 protein (rSmekTPx-1) was expressed and produced. Diagnostic performance of the rSmekTPx-1 antigen through ELISA for detecting human schistosomiasis was compared with that of recombinant protein of S. japonicum TPx-1 (rSjTPx-1) using serum samples collected from endemic foci in Cambodia. The sensitivity and specificity of rSmekTPx-1 in ELISA were 89.3% and 93.3%, respectively, while those of rSjTPx-1 were 71.4% and 66.7%, respectively. In addition, a higher Kappa value of 0.82 calculated between rSmekTPx-1 antigen ELISA and Kato-Katz confirmed better agreement than between rSjTPx-1 antigen ELISA and Kato-Katz (Kappa value 0.38). These results suggest that ELISA with rSmekTPx-1 antigen can be a potential diagnostic method for detecting active human S. mekongi infection.
• Comparative mitogenomics elucidates the population genetic structure of Amblyomma testudinarium in Japan and a closely related Amblyomma species in Myanmar
  Wessam Mohamed Ahmed Mohamed; Mohamed Abdallah Mohamed Moustafa; May June Thu; Keita Kakisaka; Elisha Chatanga; Shohei Ogata; Naoki Hayashi; Yurie Taya; Yuma Ohari; Doaa Naguib; Yongjin Qiu; Keita Matsuno; Saw Bawm; Lat Lat Htun; Stephen C. Barker; Ken Katakura; Kimihito Ito; Nariaki Nonaka; Ryo Nakao
  Evolutionary Applications, 15, 7, 1062, 1078, Wiley, Jul. 2022, [Peer-reviewed]
  Scientific journal
• Resolution of cryptic species complexes within the genus Metagonimus (Trematoda: Heterophyidae) in Japan, with descriptions of four new species.
  Minoru Nakao; Takanori Ishikawa; Yusuke Hibino; Yuma Ohari; Rintaro Taniguchi; Tomohiro Takeyama; Shingo Nakamura; Wataru Kakino; Hiromi Ikadai; Mizuki Sasaki
  Parasitology international, 90, 102605, 102605, 25 May 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, A nationwide fish survey was conducted in Japan to detect metacercariae of the genus Metagonimus (Trematoda: Heterophyidae). The metacercariae were subjected to DNA barcoding for molecular species identification. A phylogeny inferred from the sequences of mitochondrial cytochrome c oxidase subunit 1 (cox1) prompted us to recognize three cryptic species complexes (i.e., the M. miyatai complex, the M. takahashii complex, and the M. katsuradai complex). Each complex included one or two undescribed species. For morphological description, adult flukes of each species were raised through the experimental infections of immunosuppressed mice. We propose M. saitoi n. sp., M. kogai n. sp., M. shimazui n. sp., and M. kinoi n. sp., based on their phylogeny, morphology, biogeography, and ecology (host-parasite relationships). The originally described species, M. miyatai, was split into M. miyatai sensu stricto and M. saitoi n. sp. The former is distributed mainly in eastern Japan and uses the sweetfish (Plecoglossus altivelis) and daces (Pseudaspius hakonensis and Ps. sachalinensis) as principal second intermediate hosts, while the latter is in western Japan and its principal fish hosts are the dark chub (Nipponocypris temminckii) and the pale chub (Opsariichthys platypus). The present survey resolves a long-standing controversy on the microtaxonomy of Metagonimus in Japan since the first discovery of Metagonimus yokogawai in 1912, and shows that 10 species of Metagonimus are still distributed in Japan, although human metagonimiasis is almost eradicated.
• Genotyping of Theileria parva populations in vaccinated and non-vaccinated cattle in Malawi.
  Elisha Chatanga; Yuma Ohari; Walter Muleya; Kyoko Hayashida; Chihiro Sugimoto; Ken Katakura; Nariaki Nonaka; Ryo Nakao
  Parasitology, 1, 8, 11 Apr. 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Theileria parva is an apicomplexan protozoan parasite that causes bovine theileriosis (East Coast Fever; ECF) in central, eastern and southern Africa. In Malawi, ECF is endemic in the northern and central regions where it has negatively affected the development of dairy industry. Despite its endemic status the genetic population structure of T. parva in Malawi is currently unknown. To obtain an understanding of T. parva in Malawi, we performed population genetics analysis of T. parva populations in cattle vaccinated with the Muguga cocktail live vaccine and non-vaccinated cattle using mini- and microsatellite markers covering all the four T. parva chromosomes. The T. parva Muguga strain was included in this study as a reference strain. Linkage disequilibrium was observed when all samples were treated as a single population. There was sub-structuring among the samples as shown by the principal coordinate analysis. Majority of the samples clustered with the T. parva Muguga reference strain suggesting that the isolates in Malawi are closely related to the vaccine component, which support the current use of Muguga cocktail vaccine to control ECF. The clustering of samples from non-endemic southern region with those from endemic central region suggests expansion of the distribution of T. parva in Malawi.
• The causative agents of fascioliasis in animals and humans: Parthenogenetic Fasciola in Asia and other regions
  Tadashi Itagaki; Kei Hayashi; Yuma Ohari
  Infection, Genetics and Evolution, 99, 105248, 105248, Elsevier BV, Apr. 2022, [Peer-reviewed]
  Scientific journal
• Molecular analyses confirm the coexistence of Fasciola gigantica and parthenogenetic Fasciola in the Philippines.
  Tadashi Itagaki; Sakura Jin; Syunsuke Takashima; Yuma Ohari; Jose Ma M Angeles
  Parasitology international, 88, 102562, 102562, 18 Feb. 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Fasciola flukes collected from domestic buffalos and cattle in the Philippines were confirmed as Fasciola gigantica and parthenogenetic Fasciola based on DNA analyses of nuclear pepck and pold genes, and the mitochondrial ND1 gene. This study is the first to elucidate that F. gigantica and parthenogenetic Fasciola coexist in the Philippines with prevalences of 90.6% and 9.4%, respectively. The F. gigantica population showed a high genetic diversity with 25 ND1 haplotypes, suggesting that F. gigantica has existed in the Philippines for a long time. In contrast, parthenogenetic Fasciola flukes showed a single ND1 haplotype (Fsp-ND1-P1), which was identical to the founder haplotype, Fg-C2 of parthenogenetic Fasciola in China. These results indicate that parthenogenetic Fasciola in the Philippines is a recently introduced population from a neighboring continent.
• Brachylaima phaedusae n. sp. (Trematoda: Brachylaimidae) from door snails in Japan.
  Tsukasa Waki; Minoru Nakao; Mizuki Sasaki; Hiromi Ikezawa; Ken Inoue; Yuma Ohari; Yuichi Kameda; Masahito Asada; Haruki Furusawa; Shinsuke Miyazaki
  Parasitology international, 86, 102469, 102469, Feb. 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, The metacercarial infections of door snails (Gastropoda: Clausiliidae) with unknown species of the genus Brachylaima (Trematoda: Brachylaimidae) have recently been reported in eastern Honshu and Kyushu, Japan. A large scale snail survey was carried out to clarify their taxonomic status. From the period of 2015 to 2020, a total of 1239 land snails (768 door snails and 471 others) were collected from 32 localities in Honshu, Shikoku, and Kyushu. The resulting trematode isolates were identified as Brachylaima sp. by mitochondrial DNA barcoding. The sporocysts were found only a few from Megalophaedusa sublunellata (Clausiliidae), Tauphaedusa subaculus (Clausiliidae), and Aegista trochula (Camaenidae), while the metacercariae were frequently detected from 14 species of Clausiliidae and 2 species of other families. Although Brachylaima sp. showed a broad range of intermediate hosts, door snails seem to be very important to drive the life cycle. The gravid adults of Brachylaima sp. was experimentally raised from metacercariae using immunosuppressed mice. Morphological, phylogenetical, and ecological considerations prompted us to propose Brachylaima phaedusae n. sp. for this unknown species. The definitive hosts of the new species are completely unknown. The wide geographic distribution and high genetic diversity of the new species suggest a possibility that the definitive host is ground-foraging birds, which prefer door snails.
• Genetic and seasonal variations of Trypanosoma theileri and the association of Trypanosoma theileri infection with dairy cattle productivity in Northern Japan
  Keisuke Suganuma; Mitsunori Kayano; Katsuya Kida; Yrjö T. Gröhn; Ryotaro Miura; Yuma Ohari; Daiki Mizushima; Noboru Inoue
  Parasitology International, 86, 102476, 102476, Elsevier BV, Feb. 2022, [Peer-reviewed]
  Scientific journal
• Detection and molecular characteristics of Pyelosomum cochlear (Digenea: Pronocephalidae) in the urinary bladder of the green sea turtle (Chelonia mydas) in the Northwest Pacific Ocean
  Kei Hayashi; Chiyo Kitayama; Taizo Saito; Yuma Ohari; Kaoru Hayashi; Satomi Kondo; Yasuhiro Takashima; Toshiro Kuroki; Toshiyuki Shibahara; Tadashi Itagaki
  Infection, Genetics and Evolution, 93, 104962, 104962, Elsevier BV, Sep. 2021, [Peer-reviewed]
  Scientific journal
• Prevalence of Nosema species infections in Apis cerana japonica and Apis mellifera honeybees in the Tohoku region of Japan
  Shunsuke Takashima; Yuma Ohari; Tadashi Itagaki
  Parasitology International, 83, 102361, 102361, Elsevier BV, Aug. 2021, [Peer-reviewed]
  Scientific journal
• Do aspermic (parthenogenetic) Fasciola forms have the ability to reproduce their progeny via parthenogenesis?
  Yuma Ohari; Kei Hayashi; Yasuhiro Takashima; Tadashi Itagaki
  Journal of helminthology, 95, e36, 21 Jul. 2021, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal, Across Far East Asia, aspermic Fasciola forms are found endemically. They have abnormal spermatogenesis and oogenesis, and it is presumed that their progeny are produced parthenogenetically and clonally. Because of this, they are also termed parthenogenic Fasciola forms. Currently, there is no evidence that they do indeed reproduce parthenogenetically and clonally. In this study, the multilocus genetic type (MLG) in 12 microsatellite markers of adult flukes and their subsequent progeny larvae were analysed using two laboratory aspermic Fasciola triploid strains. The MLGs of adults and their larvae were identical for all markers evaluated, suggesting that these strains reproduce their progeny clonally. The deviation between theoretical and actual frequency within the larvae genotype of the Fh_6 locus resulted in the inability for self-fertilization within individual adult flukes. These findings strongly suggested that aspermic Fasciola forms reproduce their progeny by means of parthenogenesis, possibly gynogenesis.
• Development of a multiplex PCR method for discriminating between Heterakis gallinarum, H. beramporia, and H. indica parasites of poultry.
  Peru Gopal Biswas; Yuma Ohari; Uday Kumar Mohanta; Tadashi Itagaki
  Veterinary parasitology, 295, 109463, 109463, Jul. 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Heterakis gallinarum, H. beramporia, and H. indica are common nematodes in gallinaceous poultry in Asian countries, and the infections occasionally lead to declining health of the hosts. These three Heterakis spp. can be identified by the morphological characteristics of the male worms; however, the female worms and eggs cannot be identified because they have no reliable morphological characteristics for discrimination. In addition, H. gallinarum is a well-known vector of fetal protozoan Histomonas meleagridis, making the discrimination between these three Heterakis species important in basic and clinical veterinary parasitology. We analyzed nuclear ribosomal 18S-ITS1-5.8S-ITS2-28S DNA sequences of these three Heterakis species. The 18S, 5.8S, and 28S DNA sequences had very high homology between the species; however, the ITS1 and ITS2 sequence similarity was 68.5 %-93.2 %. H. gallinarum, H. beramporia, and H. indica were divided into separate clades in the ITS1 and ITS2-concatenated phylogenetic tree. Therefore, to develop a multiplex PCR method for discriminating between the three Heterakis species, we designed species-specific reverse primers within the ITS2 region as follows: H. gallinarum-specific HgI2-R, H. beramporia-specific HbI2-R5, and H. indica-specific HiI2-R. The multiplex PCR amplified 396-bp, 272-bp, and 482-bp fragments specific to H. gallinarum, H. beramporia, and H. indica DNA, respectively, and did not amplify the fragments using other chicken nematode DNAs such as Ascaridia galli, Oxyspirura mansoni, Dispharynx nasuta, and Cheilospirura hamulosa. These results suggest that the multiplex PCR would serve as a useful tool for identifying and diagnosing infections of H. gallinarum, H. beramporia, and H. indica in poultry.
• Applications of Blocker Nucleic Acids and Non-Metazoan PCR Improves the Discovery of the Eukaryotic Microbiome in Ticks.
  Yurie Taya; Gohta Kinoshita; Wessam Mohamed Ahmed Mohamed; Mohamed Abdallah Mohamed Moustafa; Shohei Ogata; Elisha Chatanga; Yuma Ohari; Kodai Kusakisako; Keita Matsuno; Nariaki Nonaka; Ryo Nakao
  Microorganisms, 9, 5, 13 May 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Ticks serve as important vectors of a variety of pathogens. Recently, the viral and prokaryotic microbiomes in ticks have been explored using next-generation sequencing to understand the physiology of ticks and their interactions with pathogens. However, analyses of eukaryotic communities in ticks are limited, owing to the lack of suitable methods. In this study, we developed new methods to selectively amplify microeukaryote genes in tick-derived DNA by blocking the amplification of the 18S rRNA gene of ticks using artificial nucleic acids: peptide nucleic acids (PNAs) and locked nucleic acids (LNAs). In addition, another PCR using non-metazoan primers, referred to as UNonMet-PCR, was performed for comparison. We performed each PCR using tick-derived DNA and sequenced the amplicons using the Illumina MiSeq platform. Almost all sequences obtained by conventional PCR were derived from ticks, whereas the proportion of microeukaryotic reads and alpha diversity increased upon using the newly developed method. Additionally, the PNA- or LNA-based methods were suitable for paneukaryotic analyses, whereas the UNonMet-PCR method was particularly sensitive to fungi. The newly described methods enable analyses of the eukaryotic microbiome in ticks. We expect the application of these methods to improve our understanding of the tick microbiome.
• Molecular Characterization of Ticks and Tick-Borne Pathogens in Cattle from Khartoum State and East Darfur State, Sudan.
  Ehab Mossaad; Alex Gaithuma; Yassir O Mohamed; Keisuke Suganuma; Rika Umemiya-Shirafuji; Yuma Ohari; Bashir Salim; Mingming Liu; Xuenan Xuan
  Pathogens (Basel, Switzerland), 10, 5, 10 May 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Ticks transmit many pathogens with public health and veterinary importance. Despite the wide distribution of tick-borne pathogens in Sudan, the information on the tick-pathogen relationship needs to be updated, particularly using modern molecular techniques. This cross-sectional study, conducted between September and November 2019, used morphology, PCR, and sequencing to confirm the identity of adult cattle ticks (male and female; n = 536) from Khartoum State (n = 417) and East Darfur State (n = 119). Moreover, the presence of Theileria annulata, Babesia bigemina, B. bovis, Anaplasma marginale, and Ehrlichia ruminantium was detected and confirmed in each tick using species-specific PCR or nested PCR and sequencing. The most economically important tick genera, Rhipicephalus, Hyalomma, and Amblyomma, were prevalent in the study area, and 13 different tick species were identified. The most prevalent tick species were Rhipicephalusevertsi evertsi (34.3%) and Hyalomma anatolicum (57.3%) in Khartoum State, and Rhipicephalus annulatus (27%), Rhipicephalus decoloratus (25%), and Hyalomma rufipes (29%) in East Darfur State. We detected all five pathogens in both states. To the best of our knowledge, this is the first study to report the presence of E. ruminantium, its vector Amblyomma variegatum, and B. bovis in Khartoum State. Further, this is the first report on most tick and pathogen species identified in East Darfur State. Our findings indicate the migration of some tick and pathogen species beyond their distribution areas in the country, and this consideration is necessary to develop future control strategies.
• The first detection of Dicrocoelium chinensis sporocysts from the land snail Aegista vulgivaga in Gifu Prefecture, Japan.
  Tsukasa Waki; Yuma Ohari; Kei Hayashi; Junji Moribe; Kayoko Matsuo; Yasuhiro Takashima
  The Journal of veterinary medical science, Japanese Society of Veterinary Science, 30 Apr. 2021, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, Trematodes of the genus Dicrocoelium are one of the most common parasites in ruminant animals; however, their life cycles in Japan are unclear. To find the sporocysts of D. chinensis in the natural field, we sampled 269 land snails (14 species) at a location with high level infection of sika deer in Gifu Prefecture, Honshu Island, Japan in autumn between 2017 and 2019. During the sampling period, we found mother sporocysts in the hepatopancreas of Aegista vulgivaga and Cyclophorus herklotsi. DNA barcoding based on the sequences of cytochrome c oxidase subunit 1 showed that the sporocysts from A. vulgivaga belonged to D. chinensis, indicating that this snail has potential as the first intermediate host of D. chinensis at this location.
• Molecular characterization of Ascaridia galli from Bangladesh and development of a PCR method for distinguishing A. galli from Heterakis spp.
  Peru Gopal Biswas; Yuma Ohari; Uday Kumar Mohanta; Tadashi Itagaki
  The Journal of veterinary medical science, 83, 4, 666, 670, 09 Apr. 2021, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, We analyzed the nuclear ribosomal internal transcribed spacer (ITS) 1 and ITS2 sequences for Bangladesh isolates of Ascaridia galli, and we determined that the sequences were unreliable as molecular markers for distinguishing A. galli from other Ascaridia species, because the sequences showed high identity with that of A. columbae. However, the ITS1 sequences were available for designing PCR primers distinguishable between Ascaridia galli and Heterakis spp. Bangladesh isolates of A. galli constituted a monophyletic clade along with other geographical isolates in the cytochrome c oxidase subunit I (COI) phylogenetic tree, however, we could not clarify the phylogenetic relationships between A. galli and other Ascaridia spp., because their available sequences in GenBank were very few. The developed PCR method using DNA from A. galli and Heterakis spp. eggs would enable differential diagnosis of the individual infections in the future.
• Genetic characterization of Neospora caninum from aborted bovine fetuses in Hokkaido, Japan.
  El-Sayed El-Alfy; Yuma Ohari; Naomi Shimoda; Yoshifumi Nishikawa
  Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases, 92, 104838, 104838, 02 Apr. 2021, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal, Neospora caninum is one of the main causes of bovine abortions worldwide, including Japan. Nothing is known about the N. caninum population substructures in Japan, and only one isolate from a pregnant sheep has been studied to date. This study describes, for the first time, the genetic characterization of isolates of N. caninum implicated in cattle abortions in Japan. Brains from five aborted fetuses were successfully genotyped based on multilocus microsatellite markers. Assigned genotypes showed high frequencies of mixed alleles in the sequenced markers MS7 and MS10, raising concerns about the subpopulation structures of N. caninum infecting animals in Japan. Clustering analysis of the genotypes, together with those from a previous dataset, showed that five of the six genotypes were distinct from other clusters. Meanwhile, the remaining genotype, together with the sheep isolate from Japan, was grouped with those from Mexico and Spain. These preliminary data may indicate a complex transmission pattern of N. caninum in Japan via clonal spreading by vertical and horizontal transmission and geographically related population substructuring.
• Genetic diversity and population structure analyses based on microsatellite DNA of parthenogenetic Fasciola flukes obtained from cattle and sika deer in Japan.
  Yuma Ohari; Kayoko Matsuo; Ayako Yoshida; Nariaki Nonaka; Hiroshi Sato; Tadashi Itagaki
  Parasitology research, 120, 4, 1341, 1350, Apr. 2021, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal, Understanding the population structure of Fasciola flukes in domestic and wild animals is important for determining the extent of cross-infection between them. Although the parthenogenetic Fasciola flukes in Japan have been shown to comprise five genetic types based on the ribosomal internal transcribed spacer 1 (ITS1) and mitochondrial NADH dehydrogenase subunit 1 (nad1) regions, these genetic regions are not suitable for analyzing their population structure. In the present study, the genetic diversity and population structure of the parthenogenetic Fasciola flukes in Japan were studied using microsatellite DNA, ITS1, and nad1 regions. A total of 144 parthenogenetic Fasciola flukes, obtained from cattle and sika deer in 16 localities, were individually analyzed using PCR-RFLP for ITS1, PCR-direct sequence analysis for nad1, and post-labeling PCR and capillary electrophoresis for microsatellite DNA regions. The flukes showed higher genetic diversity in the microsatellite DNA regions than ITS1 and nad1. The population structures of parthenogenetic Fasciola flukes were unclear, however, it was suggested that the flukes are more diverse populations. We hypothesized that their distribution throughout Japan is closely related to livestock movement dependent on human activity. Moreover, it is considered that cross-infection of the flukes between cattle and sika deer possibly has occurred in the past.
• Development of conventional multiplex PCR method for discrimination between Dispharynx nasuta and Cheilospirura hamulosa (Nematoda: Acuariidae) parasitizing poultry.
  Peru Gopal Biswas; Yuma Ohari; Uday Kumar Mohanta; Tadashi Itagaki
  The Journal of veterinary medical science, 83, 2, 226, 229, 25 Feb. 2021, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, The poultry infections caused by Dispharynx nasuta and Cheilospirura hamulosa nematodes are difficult to be diagnosed by fecal examination because of their egg similarity. In this study, we analyzed DNA sequences of nuclear ribosomal 18S-ITS1-5.8S-ITS2-28S region of D. nasuta and C. hamulosa and developed conventional multiplex PCR method using species-specific primers for discriminating between the two species. The method amplified 455-bp and 319-bp fragments specific to D. nasuta and C. hamulosa, respectively, and did not produce them against the other chicken nematode species, Ascaridia galli, Oxyspirura mansoni, Heterakis gallinarum, Heterakis beramporia, and Heterakis indica, suggesting that the multiplex PCR is sensitive and available for species diagnosis.
• Molecular characterization revealed Fasciola specimens in Ecuador are all Fasciola hepatica, none at all of Fasciola gigantica or parthenogenic Fasciola species.
  Shinpei Kasahara; Yuma Ohari; Sakura Jin; Manuel Calvopina; Hidekazu Takagi; Hiromu Sugiyama; Tadashi Itagaki
  Parasitology international, 80, 102215, 102215, Feb. 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, All 225 Fasciola flukes obtained from domestic animals (73 cattle, 7 sheep and 1 pig) of 18 distinct geographic areas in Ecuador-South America, were identified as Fasciola hepatica, based on molecular analyses of nuclear pepck and pold genes, and mitochondrial nad1gene as well as the morphological observation of sperm within the seminal vesicles. Fasciola gigantica and parthenogenic Fasciola forms endemic to Asian countries were not found in this study, although zebu cattle and water buffalos have introduced into South America from Asia; this could be due to the absence of suitable intermediate host snails. The results of pepck analysis using multiplex PCR developed previously showed that 32 of the flukes could not be confirmed as F. hepatica, suggesting that the method is unreliable for the accurate discrimination of F. hepatica, and that pepck gene of the species consists of multiple loci, not a single locus. The results of genetic diversity, phylogenetic, and network analyses based on mitochondrial nad1 sequences suggest that F. hepatica populations in South America, including Ecuador, formed from the ancestral F. hepatica individuals introduced into the continent along with anthropogenic movement of livestock infected with the species.
• Molecular characterization of Oxyspirura mansoni and Philophthalmus gralli collected from the eyes of domestic chickens in Bangladesh.
  Peru Gopal Biswas; Yuma Ohari; Uday Kumar Mohanta; Tadashi Itagaki
  Parasitology international, 80, 102243, 102243, Feb. 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, A variety of helminths have been found in domestic chickens in Bangladesh, but little is known about their gene sequences. Here, parasitic nematodes and trematodes were collected from the eyes of domestic chickens and analyzed for their morphological and morphometric characteristics, and characterized molecularly. The helminths were identified as Oxyspirura mansoni and Philophthalmus gralli. The ITS1 and ITS2 sequences of O. mansoni were 532 bp and 306 bp in length, respectively, and showed low identity (50.7-62.7%) with those of O. petrowi and O. conjunctivalis. Furthermore, the O. mansoni CO1 sequences (393 bp) showed five haplotypes (97.5-99.5% similarity) that formed a monophyletic clade. With respect to P. gralli, the ITS1 (452 bp) and ITS2 (736 bp) sequences showed 100% similarity with the reference sequences in GenBank. Both the ND1 and CO1 phylograms showed that P. gralli from Bangladesh, Costa Rica and Peru form a monophyletic clade, distinct from the clades of P. lucipetus and P. lacrymosus. Our data show that, Philophthalmus gralli isolates from Bangladesh, Costa Rica and Peru are genetically close to each other.
• Multigene typing and phylogenetic analysis of Fasciola from endemic foci in Iran.
  Ehsan Javanmard; Yuma Ohari; Amir Sadeghi; Kourosh Cheraghipour; Hamid Asadzadeh Aghdaei; Hamed Mirjalali; Mohammad Reza Zali; Tadashi Itagaki
  Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases, 80, 104202, 104202, Jun. 2020, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Fasciolosis is a public health problem originally transmitted from livestock. Although molecular analysis of the nuclear and mitochondrial genes allow discrimination between the two known species of Fasciola, F. hepatica and F. gigantica, these markers do not permit the detection of hybrid forms. On the other hand, molecular analysis of the pepck and pold genes from Fasciola do permit the detection of hybrid isolates and this study has not yet been performed on specimens from human and domesticated animals in Iran. Therefore, the aim of this study was to molecularly analyze Fasciola isolates using both conventional and the two new genetic markers mentioned above. Fifty-three adult Fasciola worms were isolated from the livers of 28 domesticated animals, including sheep, cattle and goat. Moreover, an adult worm was obtained from the bile duct of an infected woman during endoscopic retrograde cholangio-pancratography (ERCP). Targeted fragments from the ITS-1, NDI and COX1 genes were amplified using specific primers. PCR products were sequenced and genetically analyzed using MEGA v.7 and DnaSP software. Additionally, the pepck and pold regions were amplified and analyzed using multiplex PCR and RLFP-PCR, respectively. Multiple alignment of sequenced fragments showed highest similarity among the ITS-1 sequences isolated from all four hosts in comparison to the other genes. Furthermore, sequence diversity across the COX1 was higher than the NDI and ITS-1. Diversity among sequences isolated from cattle was higher than those from sheep and goat in all three genes. Tajima's D and Fu's Fs were negative and statistically significant for all the genes except ITS-1. Phylogenetic trees showed that the human F. hepatica isolate was closer to sheep isolates. The results of the pepck and pold analyses showed that all isolates were F. hepatica and there were no hybrid forms among samples. The molecular analyses corroborated this finding.
• Phylogenetic relationships between Lymnaeidae in relation to infection with Fasciola sp. in Hokkaido, Japan
  Yuma Ohari; Kei Hayashi; Uday Kumar Mohanta; Tatsuo Oshida; Tadashi Itagaki
  Molluscan Research, 40, 2, 160, 168, 02 Apr. 2020, [Peer-reviewed], [Lead author]
  English, Scientific journal
• Serological and molecular detection of selected hemoprotozoan parasites in donkeys in West Omdurman, Khartoum State, Sudan.
  Afraa Elata; Ehab Mossaad; Rawan Satti; Nadia Matar; Yuma Ohari; Xuenan Xuan; Noboru Inoue; Keisuke Suganuma
  The Journal of veterinary medical science, 82, 3, 286, 293, 05 Mar. 2020, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, In Sudan, donkeys are important animals, providing transportation and income possibilities. However, the prevalence of parasites in donkeys in Sudan has not been thoroughly characterized. Accordingly, in this study, we aimed to detect selected hemoprotozoan parasites in donkeys in West Omdurman, Khartoum State, Sudan, wherein people depend mainly on donkeys for their daily life. In total, 198 blood samples collected from donkeys in a local market in West Omdurman, were screened using serological and molecular diagnostic techniques. Serologically, 52 (26.3%), 56 (28.3%), and 19 (9.6%) samples were positive for trypanosomosis using Card Agglutination Test for Trypanosoma evansi, Trypanosoma evansi crude antigen -based enzyme-linked immuno sorbent assay (ELISA) and recombinant Trypanosoma evansi GM6-4r-based ELISA, respectively. ELISA for equine piroplasmosis revealed 156 (78.8%) and 10 (5.1%)Theileria equi- and Babesia caballi-positive samples, respectively. PCR detected Trypanosoma congolense, subgenus Trypanozoon, Theileria equi, and Babesia caballi in 18 (9.1%), 77 (38.9%), 18 (9.1%), and 8 (4%) samples, respectively. Of the 77 Trypanozoon-positive samples, 35 (45.5%) were confirmed as Trypanosoma evansi type A. To our knowledge, this is the first report of detection of Trypanosoma congolense in donkeys outside of tsetse-infested areas in Sudan.
• A rebuttal letter to Letter to the Editor by P. Heneberg on "Taxonomic comments on the validity of Echinostoma miyagawai Ishii, 1932 (Trematoda: Echinostomatidae)".
  Uday Kumar Mohanta; Takuya Watanabe; Anisuzzaman; Yuma Ohari; Tadashi Itagaki
  Parasitology international, 74, 101971, 101971, Feb. 2020, [Peer-reviewed], [International Magazine]
  English
• The prevalence and molecular characterization of Acarapis woodi and Varroa destructor mites in honeybees in the Tohoku region of Japan.
  Shunsuke Takashima; Yuma Ohari; Tadashi Itagaki
  Parasitology international, 75, 102052, 102052, 09 Jan. 2020, [Peer-reviewed], [International Magazine]
  English, Honeybee acarapiosis and vorrosis were designated as Notifiable Infectious Diseases in the Act on Domestic Animal Infectious Diseases Control by the Minister of Agriculture, Forestry and Fisheries of Japan in 1997. However, the prevalences of A. woodi and V. destructor in Japan, especially in the Tohoku region, have not been sufficiently elucidated. This study was designed to clarify the prevalence of A. woodi and V. destructor mites in Apis cerana japonica and Apis mellifera in the Tohoku region and the characteristics of their mitochondrial cytochrome c oxidase I (COI) DNA. Acarapis woodi mites were detected from 13.5% of A. c. japonica and 0% of A. mellifera. Aomori prefecture, Japan is a new distribution locality for A. woodi. None of the honeybees examined showed infection by V. destructor mites. The COI sequences (1638 bp) of A. woodi were identical and phylogenetically closely related to those of A. woodi from Japan and the UK, suggesting that the mite would have been introduced into Japan with A. mellifera during the last 150 years and spread throughout the country.
• First report of Paragonimus skrjabini miyazakii metacercariae in Geothelphusa dehaani (Sawagani) occurring in Iwate Prefecture, Japan.
  Yuma Ohari; Yuma Suzuki; Toshiyuki Shibahara; Tadashi Itagaki
  The Journal of veterinary medical science, 81, 8, 1109, 1112, 09 Aug. 2019, [Peer-reviewed], [Lead author], [Domestic magazines]
  English, Paragonimiasis is an important food-borne zoonosis caused by Paragonimus flukes and is endemic to western Japan. However, there have been few epidemiological studies in the Tohoku district of northeastern Japan. In this study, Paragonimus metacercariae (mc) was detected in Geothelphusa dehaani (Japanese freshwater crab or Sawagani) in Iwate Prefecture. Out of the 207 Sawagani collected from 35 localities, 12 individuals from six localities were infected with Paragonimus mc. The mc were identified as P. skrjabini miyazakii based on the sequences of nuclear ribosomal internal transcribed spacer 2 and mitochondrial cytochrome c oxidase I. This is the first report of P. s. miyazakii mc infection in Sawagani in Iwate Prefecture.
• Infection by and Molecular Features of Learedius learedi (Digenea: Schistosomatoidea) in Green Sea Turtles (Chelonia mydas) on the Ogasawara Islands, Japan
  Chiyo Kitayama; Kei Hayashi; Yuma Ohari; Satomi Kondo; Toshiro Kuroki; Toshiyuki Shibahara; Tadashi Itagaki
  Journal of Parasitology, 105, 4, 533, 533, American Society of Parasitologists, 16 Jul. 2019, [Peer-reviewed]
  Scientific journal, Learedius learedi Price, 1934 , is a blood fluke found in sea turtles, and the adult fluke parasitizes the cardiovascular system of the host. In this study we surveyed 46 green sea turtles, Chelonia mydas, on the Ogasawara Islands, Japan, and blood flukes were detected in the heart and blood vessels of 26 turtles. The flukes were identified as L. learedi based on a detailed morphological description. In addition, molecular identification and characterization of the parasite were performed. The nucleotide sequences of nuclear internal transcribed spacer 2 (ITS2) regions were almost identical to those of L. learedi reported previously, but not to those of Hapalotrema spp., which is the closest related genus. The nucleotide sequences of the 28S ribosomal DNA region formed a single clade with those of the reference L. learedi in the phylogenetic tree, but not with those of Hapalotrema spp. Therefore, the nucleotide sequences of ITS2 and 28S are robust markers for distinguishing L. learedi from other species. The nucleotide sequences of the mitochondrial cytochrome c oxidase subunit 1 (COI) region were analyzed to evaluate the genetic variations in L. learedi. The COI haplotypes revealed the extremely high genetic diversity of the species as well as the host turtles on the Ogasawara Islands. The haplotype frequency in the mitochondrial DNA of the green sea turtles on the Ogasawara Islands is known to be significantly different from those in other Pacific rookeries. Although the number of analyzed flukes is small in this study, no haplotype was close to that in other areas; on the basis of the data, we hypothesized that L. learedi differentiated along with the host turtles on the Ogasawara Islands.
• Characterization of Echinostoma revolutum and Echinostoma robustum from ducks in Bangladesh based on morphology, nuclear ribosomal ITS2 and mitochondrial nad1 sequences
  Uday Kumar Mohanta; Takuya Watanabe; Anisuzzaman; Yuma Ohari; Tadashi Itagaki
  Parasitology International, 69, 1, 7, Elsevier {BV}, Apr. 2019, [Peer-reviewed]
  English, Scientific journal
• Morphological and genetic characterization of green-banded broodsacs of Leucochloridium (Leucochloridiidae: Trematoda) sporocysts detected in Succinea lauta in Hokkaido, Japan
  Yuma Ohari; Yasuhiro Kuwahara; Tadashi Itagaki
  Parasitology International, 68, 1, 53, 56, Elsevier {BV}, Feb. 2019, [Peer-reviewed], [Lead author]
  English, Scientific journal
• Molecular characterization of Fasciola flukes obtained from wild sika deer and domestic cattle in Hokkaido, Japan
  Madoka Ichikawa-Seki; Tomoko Shiroma; Tatsuya Kariya; Ryo Nakao; Yuma Ohari; Kei Hayashi; Shinya Fukumoto
  Parasitology International, 66, 5, 519, 521, Elsevier Ireland Ltd, 01 Oct. 2017, [Peer-reviewed]
  English, Scientific journal
• Phylogenetic relationships between Dicrocoelium chinensis populations in Japan and China based on mitochondrial nad1 gene sequences
  Kei Hayashi; WenQiang Tang; Yuma Ohari; Maiko Ohtori; Uday Kumar Mohanta; Kayoko Matsuo; Hiroshi Sato; Tadashi Itagaki
  Parasitology Research, 116, 9, 2605, 2609, Springer Verlag, 01 Sep. 2017, [Peer-reviewed]
  English, Scientific journal
• Gastrointestinal pseudoparasitism by chestnut weevil (Curculio sikkimensis) larvae in a dog
  Y. Sato; Y. Ohari; T. Itagaki
  Journal of Small Animal Practice, 58, 5, 302, Blackwell Publishing Ltd, 01 May 2017, [Peer-reviewed]
  English, Scientific journal
• First detection of Allobilharzia visceralis (Schistosomatidae, Trematoda) from Cygnus cygnus in Japan
  Kei Hayashi; Madoka Ichikawa-Seki; Yuma Ohari; Uday Kumar Mohanta; Junya Aita; Hiroshi Satoh; Shiori Ehara; Minami Tokashiki; Tomoko Shiroma; Ayumi Azuta; Nozomi Oka; Takuya Watanabe; Ryo Harasawa; Satoshi Inohana; Toshihiro Ichijo; Kazuhisa Furuhama
  Parasitology International, 66, 1, 925, 929, Elsevier Ireland Ltd, 01 Feb. 2017, [Peer-reviewed]
  English, Scientific journal
• Inducing factors of pseudoparasitism by chestnut weevil (Curculio sikkimensis) larvae in a dog.
  Yoshihiko Sato; Yuma Ohari; Tadashi Itagaki
  J. Vet. Med. (Tokyo), 70, 11, 851, 855, 文永堂出版, 2017, [Peer-reviewed]
  Japanese, Scientific journal
• First report of fasciola larva infection in Galba truncatula (Müller, 1774) (Gastropoda, Lymnaeidae) occurring in the natural environment in Hokkaido, Japan
  Yuma Ohari; Kei Hayashi; Uday Kumar Mohanta; Yasuhiro Kuwahara; Tadashi Itagaki
  Journal of Veterinary Medical Science, 79, 8, 1381, 1383, Japanese Society of Veterinary Science, 2017, [Peer-reviewed], [Lead author]
  English, Scientific journal
• Molecular phylogenetic relationship of Dicrocoelium dendriticum from Japan and China based on nucleotide sequences of the mitochondrial nad1
  HAYASHI, Kei; OHTORI, Maiko; OHARI, Yuma; MOHANTA; Uday Kumar; WenQiang, TANG; ITAGAKI, Tadashi
  Japanese Journal of Veterinary Parasitology, 15, 1, 12, 18, 2016, [Peer-reviewed]
  English, Scientific journal
• Genetic characterization of Fasciola flukes detected from wild sika deer in Hokkaido, Yamaguchi and Miyazaki prefectures, Japan
  Yuma Ohari; Hiroshi Sato; Nariaki Nonaka; Kumar Mohanta Uday; Kei Hayashi; Tadashi Itagaki
  Japanese Journal of Veterinary Parasitology, 15, 2, 80, 83, 2016, [Peer-reviewed], [Lead author]
  English, Scientific journal
• Molecular characterization and phylogenetic analysis of Explanatum explanatum in India based on nucleotide sequences of ribosomal ITS2 and the mitochondrial gene nad1
  Kei Hayashi; Uday K. Mohanta; Yuma Ohari; Tambireddy Neeraja; T. Shantikumar Singh; Hiromu Sugiyama; Tadashi Itagaki
  Journal of Veterinary Medical Science, 78, 11, 1745, 1748, Japanese Society of Veterinary Science, 2016, [Peer-reviewed]
  English, Scientific journal
• Survey on Prevalence of Fosciola sp. in Sika Deer （Cervus nippon yesoensis） in Tokachi District, Hokkaido, Japan
  Yuma OHARI; Tatsuo OSHIDA
  Japanese Journal of Zoo and Wildlife Medicine, 18, 4, 115, 120, Japanese Society of Zoo and Wildlife Medicine, 2013, [Peer-reviewed], [Lead author]
  Japanese, Scientific journal, Liver flukes are highly parasitic on sika deer in Japan, although it is not highly on livestock such ascattle and sheep. Recently, sika deer are remarkably increasing in Hokkaido, Japan. Therefore, liver flukes may spread more in Hokkaido as sika deer expand their range. Liver flukes may also expand to livestock and to human. To maintain livestock industry and human health, it is important to understand the current situation of liver fluke parasitism of sika deer. We investigated frequency sika deer are parasitized in the Tokachi District, a dairy farming area typical to Hokkaido. We collected 507 feces samples of sika deer from 10 study sites in Tokachi from May to October, 2012. We examined these feces for liver fluke eggs. Prevalence in Tokachi was 14.2%. In each study site, we compared the prevalence of sika deer with that of cattle reported by the Hokkaido Obihiro Meat Inspection Center. In some study sites, both species had liver fluke. To prevent liver flukes from spreading to live stock and humans, further survey of liver fluke parasitism of sika deer is needed.

• 有鉤条虫Taenia soliumは「出アフリカ」で広がったのか?:アフリカ起源説についての再考
  林直樹; 桑本亮; 岡田充弘; 鈴木健太; 法華津孝哉; SAMUEL Kelava; 尾針由真; 岡本宗裕; 八木欣平; 野中成晃; 中尾亮, 日本寄生虫学会大会プログラム・抄録集, 94th (CD-ROM), 2025
• Population genetic analysis of nine ixodid tick species in Japan.
  沼田栄花; 尾針由真; QIU Yongjin; 篠塚千恵子; 佐藤梢; 川端寛樹; 高野愛; 安藤秀二; 林直樹; 野中成晃; 中尾亮, 衛生動物, 76, 2, 2025
• Distribution and population-genetic analysis of Lymnaeidae snails in Aomori Prefecture.
  高山湧太; 上原子勇一; 中村咲蓮; 中山和彦; 原口麻子; 箱崎純; 草木迫浩大; 尾針由真; 板垣匡; 筏井宏実, 衛生動物, 75, 2, 2024
• Inhabitation survey of Lymnaeidae snails in Aomori Prefecture.
  上原子勇一; 高山湧太; 中村咲蓮; 中山和彦; 原口麻子; 箱崎純; 草木迫浩大; 尾針由真; 板垣匡; 筏井宏実, 衛生動物, 75, 2, 2024
• ゲノミクスが解き明かす日本のエキノコックスの正体:エキノコックス症コントロールを目指した集団遺伝学的アプローチ
  林直樹; 中尾亮; 尾針由真; 水谷雄基; SANGARUN Kanyatip; 入江隆夫; 孝口裕一; 日高正人; 松山紘之; 木下豪太; 岡本宗裕; 八木欣平; 野中成晃, 日本寄生虫学会大会プログラム・抄録集, 93rd, 2024
• 北海道における多包条虫Echinococcus multilocularisの集団遺伝構造
  林直樹; 中尾亮; 尾針由真; 水谷雄基; SANGARUN Kanyatip; 入江隆夫; 孝口裕一; 日高正人; 松山紘之; 木下豪太; 岡本宗裕; 八木欣平; 野中成晃, 日本獣医学会学術集会講演要旨集, 167th, 2024
• ダニ媒介性ウイルスの感染リスクに影響する生態学的要因:北海道におけるアライグマとエゾウイルスについて
  伊藤萌林; 南川未来; 伊藤萌林; 南川未来; コウバ アナスタシア; 沼田栄花; 伊藤哲治; 野中成晃; 中尾亮; 大森亮介; 尾針由真; 下鶴倫人; 坪田敏男; 松野啓太; 佐鹿万里子, 日本獣医学会学術集会講演要旨集, 167th, 2024
• Ecological surveillance of Egyptian fruit bat population hosting Marburg virus
  梶原将大; 藤岡慧明; CHANGULA Katendi; 邱永晋; 梶原亜紀奈; 手嶋優風; NDEBE Joseph; MOONGA Ladslav; 直亨則; 直亨則; 尾針由真; 林田京子; HANG’OMBE Bernard M; 川端寛樹; 澤洋文; 澤洋文; 澤洋文; 飛龍志津子; 高田礼人; 高田礼人, 日本ウイルス学会学術集会プログラム・予稿集(Web), 70th, 2023
• Comparative analysis of the eukaryotic microbiome of ticks among tick species and regions in Japan.
  田谷友里恵; MOUSTAFA Mohamed Ahmed Mohamed; 尾針由真; 松野啓太; 野中成晃; 中尾亮, 衛生動物, 74, 2, 2023
• Comprehensive microbial analysis of ticks in Japan
  田谷友里恵; MOUSTAFA Mohamed; 尾針由真; 松野啓太; 野中成晃; 中尾亮, 日本寄生虫学会大会プログラム・抄録集, 92nd, 2023
• Genetic diversity and population structure of Haemaphysalis megaspinosa on the mountain trail of the Mt. Apoi, Hokkaido
  大杉祐生; 丹羽志萌; 片田雪; 田谷友里恵; 中尾亮; 尾針由真; 浅川満彦, 日本寄生虫学会大会プログラム・抄録集, 92nd, 2023
• Risk assessment of tick-borne virus transmission from ticks using raccoon as a sentinel
  伊藤萌林; 松野啓太; 南川未来; 南川未来; 重野麻子; 有泉拓馬; 伊藤哲治; KOVBA Anastasiia; 沼田栄花; 大森亮介; 尾針由真; 中尾亮; 下鶴輪人; 坪田敏男; 佐鹿万里子, 日本野生動物医学会大会・講演要旨集, 29th, 2023
• Infection situation of liver fluke in wild mammals and snails inhabiting natural water environments and the possibility of establishing a life cycle
  Yuma Ohari, Journal of Japan Society on Water Environment, 45, 8, 261, 264, Aug. 2022, [Invited], [Lead author, Corresponding author]
  Japanese, Introduction scientific journal
• Research outline: the first detection of sporocyst of Dicrocoelium chinensis in Japan
  Tsukasa Waki; Yuma Ohari; Kei Hayashi; Junji Moribe; Kayoko Matsuo; Yasuhiro Takashima, Japanese Journal of Zoo and Wildlife Medicine, 27, 1, 35, 43, 01 Mar. 2022, [Peer-reviewed]
  Japanese Society of Zoo and Wildlife Medicine, Japanese, Introduction scientific journal
• Morphological and genetic characteristics of Ixodid Ticks Collected from Cerorhinca monocerata on Teuri Island, Hokkaido, Japan
  田谷友里恵; 佐藤遼太郎; 尾針由真; 松野啓太; 綿貫豊; 野中成晃; 中尾亮, 日本寄生虫学会大会プログラム・抄録集, 91st, 2022
• Species and genetic diversity of Diplostomidae flukes in fish eyes in Hokkaido
  尾針由真; 照井滋晴; 佐々木瑞希; 中尾稔; 野中成晃; 中尾亮, 日本寄生虫学会大会プログラム・抄録集, 91st, 2022
• Genetic diversity of Echinococcus multilocularis in Hokkaido and the verification of crossbreeding between populations
  林直樹; 入江隆夫; 尾針由真; 孝口裕一; CHATANGA Elisha; 木下豪太; 八木欣平; 中尾亮; 野中成晃, 日本寄生虫学会大会プログラム・抄録集, 91st, 2022
• 北海道天売島において渡り性海鳥から発見された未記載マダニ種の形態および遺伝的特徴
  田谷友里恵; 佐藤遼太朗; 尾針由真; 松野啓太; 綿貫豊; 野中成晃; 中尾亮, 日本獣医学会学術集会講演要旨集, 165th (CD-ROM), 2022
• ミトゲノムおよびゲノムワイド一塩基多型を用いたフタトゲチマダニの分子遺伝学的解析
  尾針由真; 草木迫浩大; 白藤(梅宮)梨可; MOHAMED Wessam Mohamed Ahmed; MOHAMED MOUSTAFA Mohamed Abdallah啓太; CHATANGA Elisha; 松野啓太; BARKER Stephen; 野中成晃; 中尾亮, 日本獣医学会学術集会講演要旨集, 164th (CD-ROM), 2021
• ゲノムワイド一塩基多型を用いたFasciola属の分子遺伝学的比較解析
  尾針由真; 林慶; 中尾亮; 野中成晃; 板垣匡, 日本獣医学会学術集会講演要旨集, 164th (CD-ROM), 2021
• マダニが保有する真核生物叢解析法の開発
  田谷友里恵; 木下豪太; MOHAMED Wessam MA; MOUSTAFA Mohamed AM; MOUSTAFA Mohamed AM; 尾針由真; 松野啓太; 野中成晃; 中尾亮, 日本獣医学会学術集会講演要旨集, 164th (CD-ROM), 2021
• Application of selective whole genome amplification (SWGA) for tick mitochondrial genome sequencing
  CHATANGA Elisha; CHATANGA Elisha; 松本干城; MOUSTAFA Mohamed Abdallah Mohamed; 尾針由真; 邱永晋; 片倉賢; 野中成晃; 中尾亮, 日本獣医学会学術集会講演要旨集, 164th (CD-ROM), 2021
• 日本における単為生殖型肝蛭の集団遺伝学的解析:野生シカと家畜ウシにおける相互伝播の解明
  尾針由真; 尾針由真; 入江隆夫; 入江隆夫; 松尾加代子; 高島康弘; 吉田彩子; 野中成晃; 野中成晃; 佐藤宏; 板垣匡, 日本獣医学会学術集会講演要旨集, 163rd, 2020
• Application of multi-epitope recombinant proteins for serodiagnosis of Asian zoonotic schistosomiasis
  DANG-TRINH Minh-Anh; DANG-TRINH Minh-Anh; ANGELES Jose Ma. M.; MOENDEG Kharleezelle J.; MACALANDA Adrian Miki C.; OHARI Yuma; WANLOP Atcharaphan; KIRINOKI Masashi; CHIGUSA Yuichi; GOTO Yasuyuki; KAWAZU Shin-ichiro, 日本寄生虫学会大会プログラム・抄録集, 89th, 2020
• ニホンジカにおける抗肺吸虫抗体の保有状況と抗体陽性シカ捕獲地周辺における肺吸虫の分布調査
  吉田彩子; 吉田彩子; 尾針由真; 長安英治; 松尾加代子; 松尾加代子; 丸山治彦; 丸山治彦; 板垣匡; 野中成晃; 野中成晃, 日本寄生虫学会大会プログラム・抄録集, 88th, 2019
• 日本産肝蛭の集団遺伝学的解析:マイクロサテライトマーカーを用いた分布拡大の解明
  尾針由真; 林慶; MOHANTA Uday Kumar; 入江隆夫; 松尾加代子; 吉田彩子; 野中成晃; 佐藤宏; 板垣匡, 日本獣医学会学術集会講演要旨集, 161st, 324, 324, 21 Aug. 2018
  (公社)日本獣医学会, Japanese
• エクアドル産Fasciola属の分子同定および系統解析
  笠原 慎平; 尾針 由真; Manuel Calvopina; 高木 秀和; 杉山 広; 板垣 匡, 日本獣医学会学術集会講演要旨集, 161回, 324, 324, Aug. 2018
  (公社)日本獣医学会, Japanese
• 日本産肝蛭の集団遺伝学的解析:マイクロサテライトマーカーを用いたクローンの多様性
  尾針由真; 尾針由真; 林慶, 林慶; MOHANTA Uday Kumar; MOHANTA Uday Kumar; 入江隆夫; 松尾加代子; 松尾加代子; 吉田彩子; 野中成晃; 佐藤宏; 板垣匡; 板垣匡, 日本獣医学会学術集会講演要旨集, 160th, 342, 342, 30 Aug. 2017
  (公社)日本獣医学会, Japanese
• マイクロサテライトマーカーによる日本産肝蛭のクローン体識別能力の検証
  尾針由真; 尾針由真; 林慶; 林慶; MOHANTA Uday Kumar; MOHANTA Uday Kumar; 佐藤宏; 野中成晃; 板垣匡, 日本寄生虫学会大会プログラム・抄録集, 86th, 2017

• The parasite epidemiology based on the parasite dynamics demonstrated by population genetics
  Yuma Ohari
  7th One Health Lecture Series, 15 Dec. 2022, English, Public discourse
  15 Dec. 2022 - 16 Dec. 2022
• 奄美群島におけるノネコおよびノラネコの寄生虫保有状況
  大杉祐生; 伊藤圭子; 常盤俊大; 尾針由真; 浅川満彦
  第68回日本寄生虫学会・日本衛生動物学会 北日本支部合同大会, 15 Oct. 2022, Japanese, Oral presentation
  15 Oct. 2022 - 15 Oct. 2022
• 国立環境研究所で保存された絶滅危惧種鳥類の消化管に寄生する蠕虫類の保有状況-継続調査結果について-
  岡田東彦; 羽賀淳; 中谷裕美子; 長嶺隆; 大沼学; 尾針由真; 浅川満彦
  第68回日本寄生虫学会・日本衛生動物学会 北日本支部合同大会, 15 Oct. 2022, Japanese, Oral presentation
  15 Oct. 2022 - 15 Oct. 2022
• 2種の飼育下ペンギン類から検出されたAustrogoniodes属ハジラミ類における種同定および宿主・寄生部位間特異性の検証
  木村優樹; 進藤英朗; 荒木悠里; 工藤健仁; 平田晴之; 尾針由真; 浅川満彦
  第68回日本寄生虫学会・日本衛生動物学会 北日本支部合同大会, 15 Oct. 2022, Japanese, Oral presentation
  15 Oct. 2022 - 15 Oct. 2022
• ストレス様状態にある飼育爬虫類の検出方法に関する文献的考察
  阿部春乃; 浅川満彦; 尾針由真; 髙橋優子
  第28回日本野生動物医学会大会, 22 Sep. 2022, Japanese, Poster presentation
  23 Sep. 2022 - 24 Sep. 2022
• 奄美大島におけるノネコ・ノラネコの糞便から検出された寄生虫
  大杉祐生; 伊藤圭子; 常盤俊大; 浅川満彦; 尾針由真
  第28回日本野生動物医学会大会, 22 Sep. 2022, Japanese, Poster presentation
  23 Sep. 2022 - 24 Sep. 2022
• 国立環境研究所における遺伝資源保存事業で対象とされた沖縄県産ケナガネズミおよび本州 産小型哺乳類の寄生蠕虫保有状況
  林美穂; 羽賀淳; 中谷裕美子; 長嶺隆; 大沼学; 浅川満彦; 尾針由真
  第28回日本野生動物医学会大会, 23 Sep. 2022, Japanese, Poster presentation
  22 Sep. 2022 - 24 Sep. 2022
• 関東の一民間動物病院から提供された野生鳥類から採集した寄生蠕虫類について
  松倉未侑; 浅川満彦; 尾針由真; 金坂裕
  第28回日本野生動物医学会大会, 23 Sep. 2022, Japanese, Poster presentation
  22 Sep. 2022 - 24 Sep. 2022
• 釧路市動物園内とその周辺地域に生息する陸棲脊椎動物の寄生蠕虫保有状況
  中本篤武; 吉野智生; 浅川満彦; 尾針由真
  第28回日本野生動物医学会大会, 23 Sep. 2022, Japanese, Poster presentation
  22 Sep. 2022 - 24 Sep. 2022
• 飼育下ペンギン類から検出された Austrogoniodes 属ハジラミ類の宿主種および寄生部位間に おける形態学的・分子学的特徴の比較
  木村優樹; 進藤英朗; 荒木悠里; 工藤健仁; 平田晴之; 尾針由真; 浅川満彦
  第28回日本野生動物医学会大会, 23 Sep. 2022, Japanese, Poster presentation
  22 Sep. 2022 - 24 Sep. 2022
• Familiar snails are also intermediate hosts for pathogenic trematodes
  Yuma Ohari
  The 93th Annual meeting of the zoological society of Japan, 07 Sep. 2022, Japanese, Nominated symposium
• Species and genetic diversity of Diplostomidae flukes in fish eyes in Hokkaido
  Yuma Ohari; Shigeharu Terui; Mizuki Sasaki; Minoru Nakao; Nariaki Nonaka; Ryo Nakao
  The 91th Annual meeting of the Japanese Society of Parasitology, 28 May 2022, Japanese, Poster presentation
  28 May 2022 - 29 May 2022
• ゲノムワイド一塩基多型を用いたFasciola属の分子遺伝学的比較解析
  尾針由真; 林慶; 中尾亮; 野中成晃; 板垣匡
  第164回日本獣医学会学術集会, 08 Sep. 2021
  07 Sep. 2021 - 13 Sep. 2021
• ミトゲノムおよびゲノムワイド一塩基多型を用いたフタトゲチマダニの分子遺伝学的解析
  尾針由真; 草木迫浩大; 白藤 (梅宮) 梨可; Wessam Mohamed Ahmed Mohamed; Mohamed Abdallah Mohamed Moustafa; Elisha Chatanga; 松野啓太; Stephen Barker; 野中成晃; 中尾亮
  第164回日本獣医学会学術集会, 08 Sep. 2021, Oral presentation
  07 Sep. 2021 - 13 Sep. 2021
• Analyses on the population genetics of Fasciola flukes reveal the cross-infection between domestic cattle and wild sika deer in Hokkaido, Japan
  Yuma Ohari; Takao Irie; Shin-ichiro Kawazu; Tadashi Itagaki
  American Society of Tropical Medicine and Hygiene 68th Annual Meeting, 22 Nov. 2019, English, Poster presentation
  [International presentation]
• 日本産肝蛭の集団遺伝学的解析：北海道のウシとシカにおける相互伝播の検証
  尾針由真; 入江隆夫; 板垣匡
  つくば, 11 Sep. 2019, Japanese, Oral presentation
  [Domestic Conference]
• 日本における単為生殖型肝蛭の分子疫学的研究～ニホンジカにおける感染の現状とその経緯～
  尾針由真
  第88回日本寄生虫学会 生態疫学談話会, 14 Mar. 2019, Japanese, Invited oral presentation
  [Invited], [Domestic Conference]
• Morphological and molecular characterization of Ascaridia galli detected from the domestic chickens in Bangladesh
  Peru Gopal Biswas; Yuma Ohari; Uday Kumar Mohanta; Tadashi Itagaki
  第64回日本寄生虫学会・日本衛生動物学会北日本市部合同大会, 2018, English, Oral presentation
  [Domestic Conference]
• pepck遺伝子をマーカーとしたmultiplex PCR はFasciola 属を正確に識別しない
  笠原慎平; 尾針由真; Calvopina Manuel; 高木秀和; 杉山 広; 板垣 匡
  第64回日本寄生虫学会・日本衛生動物学会北日本市部合同大会, 2018, Japanese
• ミトゲノムから見た日本に分布する単為生殖型肝蛭の遺伝的多様性
  尾針由真; 中尾 亮; 板垣 匡
  第64回日本寄生虫学会・日本衛生動物学会北日本市部合同大会, 2018, Japanese
• エクアドル産Fasciola属の分子同定および系統解析
  笠原 慎平; 尾針 由真; Calvopina Manuel; 高木 秀和; 杉山 広; 板垣 匡
  第161回日本獣医学会学術集会, 2018, Japanese
• 日本産肝蛭の集団遺伝学的解析：マイクロサテライトマーカーを用いた分布拡大の解明
  尾針 由真; 林 慶; Uday; Kumar Mohanta; 入江 隆夫; 松尾 加代子; 吉田 彩子; 野中 成晃; 佐藤 宏; 板垣 匡
  第161回日本獣医学会学術集会, 2018, Japanese
• Molecular characterization of Oxyspirura mansoni and Philophthalmus gralli detected from the eye of domestic chickens in Bangladesh
  Peru Gopal Biswas; Yuma Ohari; Uday Kumar Mohanta; Tadashi Itagaki
  14th International congress of parasitology, 2018
• Molecular identification and phylogenetic analysis of Fasciola flukes from Ecuador
  Shinpei Kasahara; Yuma Ohari; Manuel Calvopina; Hidekazu Takagi; Hiromu Sugiyama; Tadashi Itagaki
  14th International congress of parasitology, 2018
• Genetic structure of Fasciola population in Japan based on microsatellite DNA markers
  Yuma Ohari; Takao Irie; Kayoko Matsuo; Ayako Yoshida; Nariaki Nonaka; Hiroshi Sato; Tadashi Itagaki
  14th International congress of parasitology, 2018
• エクアドル産Fasciola属の分子学的解析
  笠原 慎平; 尾針 由真; Manuel Calvopina; 高木 秀和; 杉山 広; 板垣 匡
  第87回日本寄生虫学会大会, 2018, Japanese
• 北海道におけるモノアラガイ科貝類の肝蛭感染および遺伝学的特徴.
  尾針由真; 林慶、Mohanta; Uday Kumar; 押田龍夫; 板垣匡
  第87回日本寄生虫学会大会, 2018, Japanese
• 岩手県南部地域のサワガニから得られた宮崎肺吸虫Paragonimus miyazakii のメタセルカリアについて
  鈴木 勇磨; 尾針 由真; 柴原 壽行; 板垣 匡
  第63回日本寄生虫学会・日本衛生動物学会北日本市部合同大会, 2017, Japanese
• 北海道のオカモノアラガイSuccinea lauta から検出されたLeucochloridium 属幼虫における分子遺伝学的解析.
  尾針由真; 原康裕; 板垣匡
  第63回日本寄生虫学会・日本衛生動物学会北日本市部合同大会, 2017, Japanese
• 岩手県におけるサワガニGeothelphusa dehaaniの肺吸虫Paragonimus sp.感染状況
  鈴木 勇磨; 尾針 由真; 柴原 壽行; 板垣 匡
  第160回日本獣医学会学術集会, 2017, Japanese
• 日本産肝蛭の集団遺伝学的解析：マイクロサテライトマーカーを用いたクローンの多様性
  尾針由真; 林慶, Mohanta; Uday Kumar; 入江隆夫; 松尾加代子; 吉田彩子; 野中成晃; 佐藤宏; 板垣匡
  第160回日本獣医学会学術集会, 2017
• マイクロサテライトマーカーによる日本産肝蛭のクローン体識別能力の検証
  尾針 由真; 林 慶; Mohanta; Uday Kumar; 佐藤 宏; 野中 成晃; 板垣 匡
  第86回日本寄生虫学会大会, 2017, Japanese
• 槍形吸虫Dicrocoelium属の分類についての再評価
  林 慶; 唐文?; 鳳麻衣子; 尾針由真; 松尾加代子; 佐藤宏; Uday Kumar Mohanta; 板垣匡
  第62回日本寄生虫学会・日本衛生動物学会北日本市部合同大会, 2016, Japanese
• ホンドタヌキ（Nyctereutes procyonoides viverrinus）に寄生する鉤虫Arthrostoma miyazakiensisおよびAncylostoma kushimaenseの分子学的解析
  吾田 歩美; 尾針 由真; 板垣 匡
  第62回日本寄生虫学会・日本衛生動物学会北日本市部合同大会, 2016, Japanese
• ニホンジカから検出された日本産肝蛭の遺伝的特徴
  尾針 由真; 林 慶; Mohanta U. K; 野中 成晃; 佐藤 宏; 板垣 匡
  第62回日本寄生虫学会・日本衛生動物学会北日本市部合同大会, 2016, Japanese
• インドにおける双口吸虫Explanatum explanatumの分子学的種同定および系統解析
  林 慶; Uday; Kumar Mohanta; 尾針 由真; Neeraja Tambireddy、T. Shantikumar Singh; 杉山 広; 板垣 匡
  第159回日本獣医学会学術集会, 2016, Japanese
• 日本産肝蛭の家畜―野生動物間における相互伝播の解明：マイクロサテライトDNA領域の有用性
  尾針 由真; 林 慶; Uday Kumar Mohanta; 板垣 匡
  第159回日本獣医学会学術集会, 2016, Japanese
• 北海道におけるコシダカヒメモノアラガイの分布と肝蛭感染およびその分子学的特徴
  尾針由真; 原康裕; 板垣匡
  平成28年度日本貝類学会大会, 2016, Japanese
• 日本におけるヒメモノアラガイの分子系統解析
  尾針由真; 林慶; 福森啓晶; 松尾加代子; 板垣匡
  第85回日本寄生虫学会大会, 2016, Japanese
• 北海道十勝地方における日本産カンテツFasciola sp.およびその中間宿主モノアラガイ科貝類の分布と分子系統地理学的解析
  尾針由真; 押田龍夫
  第62回生態学会大会, 21 Mar. 2015, Japanese, Oral presentation
  [Domestic Conference]
• 北海道十勝地方におけるコシダカヒメモノアラガイの分布および分子系統学的特徴
  尾針由真; 押田龍夫
  平成27年度日本貝類学会大会, 2015, Japanese

• Studies on development of control strategy for Asian zoonotic schistosomiasis based on One Health approach
  Grants-in-Aid for Scientific Research
  Sep. 2023 - Mar. 2028
  河津 信一郎; 尾針 由真; 桐木 雅史
  Japan Society for the Promotion of Science, Fund for the Promotion of Joint International Research (International Collaborative Research), Obihiro University of Agriculture and Veterinary Medicine, 23KK0125
• 寄生虫生態学・疫学談話会 第40回記念特別会
  会議開催費助成
  Mar. 2026 - Mar. 2026
  公益財団法⼈中辻創智社, Principal investigator
• 小型哺乳類におけるウイルス相解析および宿主集団とウイルス群集の構造比較解析
  研究助成 「感染症媒介動物及び外来動物」
  Apr. 2025 - Mar. 2026
  公益財団法人 大下財団, Principal investigator
• フタトゲチマダニの系統識別法の開発および系統間における病原体媒介能の検証
  科学研究費助成事業
  Apr. 2023 - Mar. 2026
  尾針 由真
  本研究では、倍数性の異なるフタトゲチマダニHaemaphysalis longicornisの識別方法を開発し、その系統間における病原体の媒介能力の差を検証することを目的としている。本年度は、2倍体で両性生殖により次世代を産生する系統と3倍体でメスのみが単為生殖により産卵する系統のフタトゲチマダニを識別する方法として、複数のマイクロサテライトDNA領域を用いた手法開発を試みた。開発段階で、これまではデータバンクに登録されているニュージーランド産フタトゲチマダニの卵塊から解読された全ゲノムデータを用いてマイクロサテライトDNA領域の探索およびプライマー設計を行ない、100,000領域以上が発見され200領域ほどについてPCRを行なったものの、系統間の識別に適した領域を見つけることができていなかった。このため、ニュージーランドと日本のフタトゲチマダニの間で、マイクロサテライトDNA領域が異なる可能性が考えられた。そこで、日本産フタトゲチマダニの全ゲノム解析を試みようとしたところ、日本で採集された個体に由来し実験室で継代維持されていた2倍体フタトゲチマダニの全ゲノムデータが公開された。そこで、新たにデータバンクから全ゲノムデータを取得してマイクロサテライトDNA領域の探索を再度実施し、120,000領域以上のマイクロサテライトDNA領域が検出された。
  今後は検出されたマイクロサテライトDNA領域を増幅できるプライマーを設計し、系統間を識別可能な領域を探索する予定である。
  日本学術振興会, 若手研究, 北海道大学, 23K14090
• The effects of habitat and reproductive mode on the population structure of Haemaphysalis longicornis.
  Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists
  Apr. 2020 - Mar. 2023
  尾針 由真
  本研究では、生息環境や繁殖形態がフタトゲチマダニHaemaphysalis longicornis（フタトゲ）の集団構造に与える影響を明らかにし、分布拡大プロセス推定における集団構造のスタンダードモデルを提唱することを目的としている。本年度は、フタトゲのミトコンドリアゲノム（ミトゲノム）レベルおよびSNPレベルの分子系統学的および集団遺伝学的手法を用いて、さらなる解析を行なった。まず大きな集団構造を明らかにするために日本各地とオセアニア諸国で野外採集されたフタトゲおよび所属研究室で継代維持されている両性生殖系統および単為生殖系統の実験室個体を用いて解析した。その結果、ミトゲノムでは2つの大きなクレードに分かれたが、クレード間における地理的隔離による分断および繁殖形態による系統分岐は認められなかった。SNPレベルでは、海洋による地理的隔離によって分断されたフタトゲ集団が示されたが、繁殖形態による遺伝的な特徴は認められなかった。これらのことから、ミトゲノムレベルではフタトゲの大きな集団構造を示すことが困難であると考えられる。またSNPにおいても、日本国内におけるフタトゲ集団の地理的な特徴を示すことはできなかったものの、日本産とオーストラリアを除くオセアニア産のフタトゲ集団を識別できる可能性が示された。これは、日本国内では家畜による移動によりフタトゲ集団の地理的な構造が均一化してしまっていると考えられ、さらにオセアニアには過去にアジアの原産国から導入され分断されたままのフタトゲ集団が分布していると考えられる。
  また今後は小さな集団構造を明らかにするために、地理的に近い地点から採集されたフタトゲを用いて、SNPを用いた集団遺伝学的な解析の有効性を検証する。
  Japan Society for the Promotion of Science, Grant-in-Aid for Early-Career Scientists, Obihiro University of Agriculture and Veterinary Medicine, Principal investigator, 20K15674
• Studies on development of control strategy for Asian zoonotic schistosomiasis with microsatellite marker system
  Grants-in-Aid for Scientific Research Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))
  Oct. 2019 - Mar. 2023
  河津 信一郎; 尾針 由真; 桐木 雅史
  研究3年目（2021年度）には、単一寄生虫卵からDNAを調整するため、現行の「ミラシジウム孵化法」に改良を加えたプロトコールを確立した。また、フィリピン側共同研究者と研究推進Web会議を複数回実施して、このプロトコールの技術移転を試みるとともに、野外調査実施開始時期の見込み等について情報交換を行なった。また、今回の研究課題を他のアジア型住血吸虫症の研究へ展開する準備として、アジア大陸部のメコンデルタ地域（ラオスおよびカンボジアのメコン川流域に位置する一部地域）で流行するメコン住血吸虫症の調査研究において必要になる、血清診断法（酵素抗体法：ELISA）のプロトコールを検討した。研究分担者（獨協医科大学国際協力・支援センターの熱帯病寄生虫病室）にアーカイブされていたメコン住血吸虫成虫体のサンプルからRNAを抽出してRNAシーケンスを行った。得られた情報を基に、メコン住血吸虫のチオレドキシンペルオキシダーゼ-1の遺伝子を単離して、大腸菌で組換体タンパク質（rSmTPx-1）を作製した。rSmTPx-1のメコン住血吸虫症診断用ELISAへの応用を検証したところ、良好な感度（Kato-Katz法での虫卵検査陽性のカンボジア人患者血清28検体に対して89.3%）及び特異性（Kato-Katz法での虫卵検査陰性のカンボジア人住民血清30検体に対して93.3%）が得られた。ELISA 陽性・陰性のカットオフ値は住血吸虫症の非流行地（米国）住民の血清30検体に対して算定した。この結果を受けて、現在、メコン住血吸虫症診断用の組換え体ELISA抗原の開発を進めている。
  Japan Society for the Promotion of Science, Fund for the Promotion of Joint International Research (Fostering Joint International Research (B)), Obihiro University of Agriculture and Veterinary Medicine, Coinvestigator, 19KK0173
• メタバーコーディング技術による吸虫・巻貝の種多様性解析と病原性吸虫症疫学への応用
  科学研究費助成事業 特別研究員奨励費
  Apr. 2020 - Mar. 2022
  尾針 由真
  本研究課題は、巻貝に寄生した吸虫を網羅的に検出する遺伝子解析手法を確立して、吸虫類感染症流行地に特異的な吸虫および巻貝の多様性モデルを提唱することを目的としている。本研究では、巻貝から検出された吸虫のミトコンドリアゲノム（ミトゲノム）全体を網羅的に増幅および解読することで、複数種の吸虫が感染している場合でも分子学的に種判別可能な手法の開発を目標としている。
  本年度は、吸虫の幅広い分類群でミトゲノムを増幅可能なロングレンジPCR法開発について、前年度に作成したプライマーにより増幅されなかった領域を増幅可能なプライマー領域を探索した。しかし、試験用に採用した6属6種の吸虫種全てについて増幅が確認できるプライマーを設計できなかった。そこで、鎖置換型DNA合成酵素であるPhi29を用いた吸虫のミトゲノム選択的増幅法の確立を試みた。まずミトゲノム選択的増幅法に必要な吸虫のミトゲノムに相同な短鎖塩基配列を探索し、9領域を対象としたプライマーを設計した。その後、相補鎖配列の関係にあるプライマーを除去し、4つのプライマーを用いてミトゲノム選択的増幅法を行なった結果、対象領域の増幅が確認されたことから、これらのプライマーは吸虫のミトゲノムを増幅可能であると考えられる。
  また吸虫類感染症流行地と非流行地のモデルとなる地域の選定のため、北海道内における巻貝および魚類における吸虫感染状況調査を行なった。前年度の調査の結果をふまえ、Diplostomum属およびApatemon属を対象として魚類における感染状況調査を行なった結果、北海道内の48地点においてDiplostomum属に、19地点においてApatemon属に感染した魚類が採集され、両吸虫種について、遺伝的に異なる隠蔽種が含まれている可能性が示された。しかし、同所的に生息するモノアラガイを発見することができなかった。
  日本学術振興会, 特別研究員奨励費, 北海道大学, Principal investigator, 20J01329
• Population genetic analysis of ticks by MIG-seq for epidemiology of tick-borne diseases.
  Grants-in-Aid for Scientific Research Grant-in-Aid for Research Activity Start-up
  Aug. 2019 - Mar. 2020
  尾針 由真
  本研究は、農地環境と自然環境間のマダニ類およびその保有病原体の移出入を推定することを目的として、両環境間におけるマダニの集団遺伝学的構造および病原体朋友状況を明らかにすることを目的としている。集団遺伝学的解析を行なう上で次世代シーケンサーによるSNP検出を行なうこととしたが、マダニ類は体内に様々な共生細菌類を有しており、マダニ個体全体を用いてDNAを抽出すると、それらのDNAも同時に抽出してしまい、解析にバイアスが生じる懸念が有る。そこで本年度はまず、コンタミネーションを抑えたマダニ類DNA抽出法の確立を試みた。原虫病研究センターで継代維持されていたフタトゲチマダニを70%エタノールで固定し、8本の脚からフェノール/クロロホルム/イソアミルアルコールをもちいてDNAを抽出したが、DNA濃度が十分ではなかった。またフラグメント長の分布を確認したところ、DNAが短いフラグメントに断片化されており、DNAの質も十分ではないことがわかった。これは、マダニ個体を70%エタノールで固定する際に、エタノールが十分に浸透しておらず、細胞の自己融解が進んでしまった可能性が考えられる。今後、冷凍固定または生鮮個体を用いてDNA抽出を試みる予定である。
  また、マイクロサテライトDNA領域を用いた集団遺伝学的解析も可能にするために、近年データベースに登録されたニュージーランド産のフタトゲチマダニの全ゲノム解析データを用いて、マイクロサテライトDNA領域の探索も開始した。現在108,295領域を発見し、利用可能性を検証している。
  Japan Society for the Promotion of Science, Grant-in-Aid for Research Activity Start-up, Obihiro University of Agriculture and Veterinary Medicine, Principal investigator, 19K23703
• 北海道における日本産肝蛭の中間宿主コシダカヒメモノアラガイの分子系統地理学的解析
  笹川科学研究助成
  Apr. 2015 - Mar. 2016
  尾針由真
  日本科学協会, Principal investigator, Competitive research funding