博士（獣医学）, The University of Tokyo, Mar. 2014

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

Genome-wide detection of conserved stage-specific RNA editing events for nuclear genes in the Plasmodium falciparum 3D7 malaria parasite.
Md Thoufic Anam Azad; Tatsuki Sugi; Umme Qulsum; Kentaro Kato
Parasitology international, 114, 103284, 103284, 17 Apr. 2026, [International Magazine]
English, Scientific journal, RNA editing is an important post-transcriptional modification of RNA. While transcriptional variation is a well-studied phenomenon in Plasmodium, post-transcriptional modifications, such as RNA editing, have not received as much scrutiny. We detected genome-wide RNA editing in a developmental stage-specific manner at 16 h, 24 h, 32 h, and 40 h of tightly synchronized P. falciparum 3D7 by using the RNA editing computational approaches REDItools1-De novo and REDItools2. REDItools1-De novo approach revealed extensive A-to-G, G-to-A, and T-to-C type variations in almost all stages. With the REDItools2 approach and screening, almost all editing events were observed in time-specific parasitic stages. G-to-A and C-to-T events were found at much higher levels. We observed significant differences in stage-specific RNA editing at 8-h intervals. RNA editing was observed at the ring 16 h stages of the parasites, reached a peak during the 32 h trophozoite stage, and declined at the 40 h schizont stage. Adenosine deaminase expression did not correlate with the editing level in a time-dependent manner. However, the expression of cytidine deaminase was found to be higher in the 16 h of the parasites, decreased as the parasite matured. Pathways associated with RNA editing- including RNA binding, nucleic acid binding and catalytic activity acting on RNA pathways were found to be downregulated at the 40 h stage. These findings suggest the presence of robust RNA editing machinery in Plasmodium, facilitating rapid base conversions within a short timeframe. Our results provide a foundation for identifying the Plasmodium RNA editing factors and their effect in the future research.

Unveiling the tick-borne pathogens from domestic ruminant ticks in Malawi and the emergence of the brown ear tick in the southern region: implications for East Coast fever control
Boniface Chikufenji; Uday Kumar Mohanta; Elisha Chatanga; Dallion Stopher; Onur Ceylan; Rika Umemiya-Shirafuji; Oriel Thekisoe; Madalitso Nkhata; Tatsuki Sugi; Junya Yamagishi; Xuenan Xuan; Kyoko Hayashida
Parasite, 33, 22, 22, EDP Sciences, 17 Apr. 2026, [Peer-reviewed]
Scientific journal, Ticks transmit a wide range of protozoan, bacterial, and viral pathogens to humans and animals globally. However, data on ticks infesting domestic ruminants and the pathogens they carry are scarce in Malawi. In this study, we examined ticks collected from domestic ruminants and screened them for selected veterinary and medically important protozoan and bacterial pathogens. A total of 964 ticks were collected from 202 cattle, 63 goats, and 16 sheep across eleven districts in Malawi. Ticks were morphologically identified to species level using taxonomical keys, with molecular confirmation by PCR amplification and sequencing of the 12S ribosomal RNA (12S rDNA) and cytochrome c oxidase subunit I ( COI ) genes. Tick DNA was further screened for tick-borne pathogens using species-specific PCR assays. Identified tick species included Rhipicephalus microplus (30.5%), Rhipicephalus appendiculatus (23.3%), Rhipicephalus decoloratus (13.2%), Rhipicephalus evertsi (9.8%), Hyalomma rufipes (7.5%), Amblyomma variegatum (6.3%), Rhipicephalus sanguineus sensu lato (tropical lineage) (3.6%), Hyalomma truncatum (2.8%), Rhipicephalus simus (2.0%), Rhipicephalus pravus (0.6%), and Rhipicephalus annulatus (0.4%). Overall, 37.0% of ticks carried at least one tick-borne pathogen, with Theileria parva being the most prevalent (34.7%), followed by Anaplasma marginale (17.4%), Babesia bigemina (14.9%), Anaplasma ovis (11.2%), Ehrlichia ruminantium (9.2%) , Theileria mutans (8.4%), Babesia bovis (2.2%), and Anaplasma bovis (2.0%). This study provides the first molecular identification of ticks infesting domestic ruminants in Malawi and documents associated tick-borne pathogens. Notably, Rhipicephalus appendiculatus was identified for the first time in southern Malawi, refining current understanding of East Coast fever epidemiology and highlighting the need for updated surveillance approaches.

Detection of novel Pegivirus C genome in an unexplained febrile outbreak, Gombe State, Nigeria, 2024 by enhanced mNGS approach.
Maryam Sani Lawal; Kyoko Hayashida; Tatsuki Sugi; Adesuyi Ayodeji Omoare; Nuhu Bile; Haruna Ishaya Maikudi; Pius Odunzec Israel James; Felix Villeng; Olajumoke Babatunde; Jide Idris; Junya Yamagishi
International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases, 165, 108470, 108470, Apr. 2026, [International Magazine]
English, Scientific journal, OBJECTIVES: In July 2024, an outbreak of acute febrile illness occurred in Chassi village, Gombe State, Nigeria, affecting over 30 individuals, primarily children, with symptoms including fever, jaundice, abdominal pain, and mucosal bleeding. The cause remained unidentified after conventional diagnostics excluded known viral hemorrhagic fevers, malaria, and bacterial infections. This study aimed to investigate the potential etiologic agent behind the outbreak using unbiased genomic techniques. METHODS: We employed a metagenomic next-generation sequencing (mNGS) strategy with viral enrichment to analyze serum samples from 22 symptomatic patients. A novel complete 9.3 kb genome of Pegivirus C (GOMBE-017-2025) was reconstructed and phylogenetically compared to global sequences. Detection was validated using targeted PCR and Sanger sequencing. Environmental and microbial testing were conducted on local water sources. RESULTS: Pegivirus C was consistently detected in all 22 samples. The reconstructed genome showed 92.7% identity to a 2018 Nigerian strain and clustered with West African isolates. PCR and sequencing confirmed its presence. Environmental and bacterial sources were ruled out as causative agents. CONCLUSION: The uniform detection of Pegivirus C in this localized outbreak raises concern over its potential pathogenic or co-pathogenic role. These findings support the need for further investigation into its transmission dynamics, tropism, and clinical relevance.

Reported circulation of Zika and re-circulation of Chikungunya in Dengue-endemic Dhaka, Bangladesh in 2024.
Rahman Mizanur; Khan Fariduddin Ayaz; Hasan Nazmul; Rummana Rahim; Abu Hasan; Naoko Kawai; Tatsuki Sugi; Kyoko Hayashida; Junya Yamagishi
PloS one, 21, 2, e0340119, 2026, [International Magazine]
English, Scientific journal, BACKGROUND: In Dhaka, Bangladesh, dengue has been endemic for more than two decades. With the explosive outbreak of Chikungunya in 2017 and the recent report of Zika in 2023, we started routine screening of Dengue virus (DENV), Chikungunya virus (CHIKV) and Zika virus (ZIKV) of febrile patients attended in our tertiary care hospital to overcome diagnostic challenges posed by the symptomatic similarities of these viral infections. METHOD: Serum samples of 603 febrile patients from August to December 2024 were tested by multiplex RT-PCR to detect DENV, CHIKV and ZIKV. Genome sequencing and phylogenetic analysis were performed for some of these samples. RESULT: A total of 300 (49.8%) patients were positive for one or more viruses: 85 (14.1%) for DENV, 188 (31.18%) for CHIKV and 33 (5.47%) for ZIKV. Four CHIKV-DENV and two CHIKV-ZIKV co-infections were found. CHIKV sequences obtained in this study belonged to the ECSA clade and highly like those circulated in India from 2018 to 2024 but distinguished from Bangladesh strain of 2017. On the other hand, Bangladesh ZIKV sequences in 2024 belonged to the Asian clade and Southeast Asian subtype. They were most similar to strains circulated in Bangladesh in 2023, followed by sequences from Cambodia (2019), Thailand (2016) and Singapore (2016). CONCLUSION: Thus, these findings underscore the need for enhanced surveillance and public health interventions to mitigate the spread and impact of these viral infections in arboviral-endemic regions.

Presence or Emergence of Canine Leishmaniasis, Malawi.
Boniface Chikufenji; Kyoko Hayashida; Yasuyuki Goto; Tatsuki Sugi; Chizu Sanjoba; Chrispin Njala; Inga McDermott; Frederic Lohr; Dagmar Mayer; Shohei Ogata; Masahiro Kajihara; Naganori Nao; Ryo Nakao; Laston Chimaliro; Donales Kapira; Janelisa Musaya; Junya Yamagishi; Elisha Chatanga
Emerging infectious diseases, 32, 1, 137, 141, Centers for Disease Control and Prevention (CDC), Jan. 2026, [International Magazine]
English, Scientific journal, Canine leishmaniasis has long been thought to be absent in Malawi. However, our cross-sectional study in indigenous dogs showed a high prevalence of Leishmania infection in some areas, where seropositivity rates reached up to 7.0%. These findings suggest that this neglected zoonotic disease may already be endemic in Malawi.

Enhanced blood parasite species identification using V4-V9 18S rDNA barcoding by universal primers on a nanopore platform.
Tatsuki Sugi; Patrick Reteng; Alex K Gaithuma; Naoko Kawai; Boniface Namangala; Mable M Mutengo; Nobuhisa Ishiguro; Kyoko Hayashida; Junya Yamagishi
Scientific reports, 15, 1, 41249, 41249, 21 Nov. 2025, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
English, Scientific journal, Microscopic examination is commonly used for blood parasite detection in resource-limited settings due to its low cost and simplicity. However, it requires microscopy experts and has poor species-level identification. This study proposes a targeted next-generation sequencing (NGS) approach using a portable nanopore platform to enable accurate and sensitive parasite detection in such settings. To improve species identification on the error-prone nanopore sequencer, we designed a DNA barcoding strategy targeting the 18S rDNA V4-V9 region, which outperformed the commonly used V9 region. To enrich parasite DNA and reduce host contamination, two blocking primers were developed: a C3 spacer-modified oligo competing with the universal reverse primer and a peptide nucleic acid (PNA) oligo that inhibits polymerase elongation. These were combined to selectively reduce the amplification of host's DNA from blood samples. The developed targeted NGS test successfully detected Trypanosoma brucei rhodesiense, Plasmodium falciparum, and Babesia bovis in human blood samples spiked with as few as 1, 4, and 4 parasites per microliter, respectively. Validation study using field cattle blood samples revealed that this test could detect multiple Theileria species co-infections in the same cattle. The established parasite targeted NGS test using a portable nanopore platform enables comprehensive parasite detection with high sensitivity and accurate species identification.

A high prevalence of dogs seropositive to Leishmania in Zambia.
Herman M Chambaro; Kyoko Hayashida; Lavel C Moonga; Misheck Shawa; Walter Muleya; Joseph Chizimu; David Squarre; Tatsuki Sugi; Junya Yamagishi; Shohei Ogata; Masahiro Kajihara; Hirofumi Sawa; Chizu Sanjoba; Enala T Mwase; Roma Chilengi; Gilbert H Munsaka; Kelvin L Sarenje; Namwiinga R Mulunda; Mable M Mutengo; Boniface Namangala; Yasuyuki Goto
Parasitology international, 108, 103081, 103081, Oct. 2025, [Peer-reviewed], [International Magazine]
English, Scientific journal, Domestic dogs are the main reservoir of Leishmania infantum, a causative agent of visceral leishmaniasis in humans. Although the disease is widespread in the world, the burden of visceral or any other disease form of leishmaniasis is poorly documented in Zambia, largely due to lack of surveillance. Recently, three cases of autochthonous canine leishmaniasis (CanL) were reported in Zambia following decades of presumed disease absence. This finding intimated probable disease emergence, raising the need for the identification of infection foci. Thus, in this study, we conducted the first mass serological survey for Leishmania infections in domestic dogs from two densely populated urban areas of Zambia in July 2022. In some of the study sites, seropositivity was up to ∼17 %, suggesting probable presence of Leishmania transmission hot spots. Moreover, on follow-up surveys of seropositive dogs, presence of antileishmanial antibodies was a risk factor for dog survival (relative risk = 7.9; odds ratio = 42.5). Our findings implies that Leishmania infection can be a health issue in domestic dogs in Zambia. Considering the risk of zoonotic transmission, the need for improved disease diagnosis and surveillance in both humans, dogs and sand fly vectors is highlighted in Zambia.

Seroprevalence and associated behavioral factors of Toxoplasma gondii infection among pregnant women in Pokhara Valley, Nepal.
Mamata Thapa; Tulsi Ram Gompo; Tatsuki Sugi; Masahito Asada; Hiroaki Arima; Kishor Pandey
Tropical medicine and health, 53, 1, 128, 128, 30 Sep. 2025, [Peer-reviewed], [Domestic magazines]
English, Scientific journal, BACKGROUND: Toxoplasma gondii is a protozoan parasite that can cause congenital infections with serious health implications. In pregnant women, T. gondii infection poses significant risks, including miscarriage, stillbirth, and congenital abnormalities in the fetus. The burden of toxoplasmosis is often underrecognized in many developing countries, including Nepal, where awareness and routine screening are limited. This study was aimed at determining the prevalence of T. gondii infection among pregnant women in Pokhara Valley, Nepal, and to identify behavioral risk factors associated with the transmission of this parasite. METHODS: A cross-sectional study was conducted at Gandaki Medical College Teaching Hospital, Pokhara Valley, Nepal, from October 2024 to January 2025. A total of 257 serum samples were collected, 91 of which were randomly selected and tested for anti-T. gondii IgG/IgM antibodies using a rapid diagnostic test (RDT) and enzyme-linked immunosorbent assay (ELISA). Sociodemographic and behavioral data were collected using structured questionnaires. Statistical analyses included Fisher's exact test to assess associations and Cohen's kappa coefficient to evaluate the consistency between the two diagnostic methods. RESULTS: The RDT detected IgG antibodies in 19.78% (18/91) of the participants, whereas the ELISA identified 38.46% (35/91) of the participants as seropositive. No IgM-positive cases were detected by either method. Compared with the ELISA, the RDT exhibited low sensitivity (34.3%) but high specificity (89.3%), with fair consistency (kappa = 0.26). Cat ownership showed a borderline significant association with seropositivity (OR = 3.79, p = 0.05). Notably, none of the participants demonstrated any knowledge of toxoplasmosis (0%). CONCLUSIONS: The findings reveal a significant public health concern. The relatively high seroprevalence of T. gondii, combined with a lack of awareness and identifiable risk factors, underscores the urgent need for educational interventions and prenatal screening programs to reduce the risk of congenital toxoplasmosis in Nepal.

Development of a semicomprehensive detection method for paramyxoviruses and its validation using Indonesian bats.
Dela Ria Nesti; Kyoko Hayashida; Tatsuki Sugi; Wayan T Artama; Hery Wijayanto; Naoko Kawai; Junya Yamagishi
Scientific reports, 15, 1, 19154, 19154, 31 May 2025, [Peer-reviewed], [International Magazine]
English, Scientific journal, An outbreak of zoonotic diseases is one of the worldwide threats. Bats were reported as important reservoir hosts for many emerging zoonotic diseases. To mitigate the risk, understanding bat virome and their distribution is indispensable. Universal detection methods that can simultaneously identify multiple viruses are some of the most promising approaches. Here, we developed a semicomprehensive detection method integrating group-wide RT-PCR for paramyxoviruses and multiplex next-generation sequencing. The RT-PCR consists of three sets of degenerative primers covering viruses from Paramyxoviridae, including Pneumoviridae, which have now been reclassified into a distinct family. Index nucleotides were added to the primers to enable cost-effective multiplex sequencing, and the length of index was optimized to increase sensitivity. The method was applied to tracheal and rectal swabs from 135 bats captured in Indonesia. A conventional RT-PCR test validated the NGS results. Collectively, seven sequences of novel paramyxovirus-like similar to Pararubulavirus, Orthorubulavirus, and Henipavirus were successfully identified from seven bat samples. Furthermore, sequences between the two different target locations detected by NGS in the virus genomes were verified by RT-PCR. The similarity of the obtained sequences to the known paramyxoviruses sequences was relatively low, ranging from 70.88 to 82.44%. It suggests that the obtained sequences from novel viruses and the zoonotic risk of those novel viruses remain unknown. This cost-affordable, semi-comprehensive, pan-paramyxovirus test can be applied to other samples for viral genome surveillance, and the same strategy can be implemented to other pathogens for zoonosis control.

Canine Demodicosis in Rupandehi Nepal's Street Dogs: Prevalence, Clinical Signs, and Hematology.
Rachana Bhusal; Tulsi Ram Gompo; Tatsuki Sugi; Masahito Asada; Kishor Pandey
Veterinary sciences, 12, 3, 03 Mar. 2025, [Peer-reviewed], [International Magazine]
English, Scientific journal, Canine demodicosis is a contagious skin disease caused by the over-proliferation of Demodex mites in the host's hair follicles. This study examines the prevalence, clinical signs, and hematological changes associated with demodicosis in street dogs of Rupandehi, Nepal. Between August 2023 and January 2024, 100 skin scrapings were collected from each street dog presenting dermatological symptoms. The samples, treated with 10% KOH and microscopically examined, revealed a 21% positivity rate for demodicosis, with all cases involving Demodex canis. The infection predominantly affected young puppies (37.5%), females (21.6%), mixed breeds (33.3%), and dogs with above-ideal body conditions (25%). There was no significant association between infection and variables such as age, gender, breed, or nutritional status. Clinically, all affected dogs exhibited alopecia, primarily on the legs. Hematological assessments indicated significant increases in neutrophils and eosinophils and a notable decrease in mean corpuscular hemoglobin concentration and lymphocytes among infected dogs (p < 0.05). This study underscores the importance of vigilant monitoring and comprehensive diagnostic practices in effectively managing and treating canine demodicosis, especially in street dogs.

Detection of Developmental Asexual Stage-Specific RNA Editing Events in Plasmodium falciparum 3D7 Malaria Parasite.
Md Thoufic Anam Azad; Tatsuki Sugi; Umme Qulsum; Kentaro Kato
Microorganisms, 12, 1, 10 Jan. 2024, [Peer-reviewed], [International Magazine]
English, Scientific journal, Transcriptional variation has been studied but post-transcriptional modification due to RNA editing has not been investigated in Plasmodium. We investigated developmental stage-specific RNA editing in selected genes in Plasmodium falciparum 3D7. We detected extensive amination- and deamination-type RNA editing at 8, 16, 24, 32, 40, and 46 h in tightly synchronized Plasmodium. Most of the editing events were observed in 8 and 16 h ring-stage parasites. Extensive A-to-G deamination-type editing was detected more during the 16 h ring stage (25%) than the 8 h ring stage (20%). Extensive U-to-C amination-type editing was detected more during the 16 h ring stage (31%) than the 8 h ring stage (22%). In 28S, rRNA editing converted the loop structure to the stem structure. The hemoglobin binding activity of PF3D7_0216900 was also altered due to RNA editing. Among the expressed 28S rRNA genes, PF3D7_0532000 and PF3D7_0726000 expression was higher. Increased amounts of the transcripts of these two genes were found, particularly PF3D7_0726000 in the ring stage and PF3D7_0532000 in the trophozoite and schizont stages. Adenosine deaminase (ADA) expression did not correlate with the editing level. This first experimental report of RNA editing will help to identify the editing machinery that might be useful for antimalarial drug discovery and malaria control.

Toxoplasma gondii chitinase-like protein TgCLP1 regulates the parasite cyst burden.
Hironori Bando; Yuho Murata; Yongmei Han; Tatsuki Sugi; Yasuhiro Fukuda; David J Bzik; Barbara A Fox; Kentaro Kato
Frontiers in cellular and infection microbiology, 14, 1359888, 1359888, 2024, [Peer-reviewed], [International Magazine]
English, Scientific journal, Toxoplasma, an important intracellular parasite of humans and animals, causes life-threatening toxoplasmosis in immunocompromised individuals. Although Toxoplasma secretory proteins during acute infection (tachyzoite, which divides rapidly and causes inflammation) have been extensively characterized, those involved in chronic infection (bradyzoite, which divides slowly and is surrounded by a cyst wall) remain uncertain. Regulation of the cyst wall is essential to the parasite life cycle, and polysaccharides, such as chitin, in the cyst wall are necessary to sustain latent infection. Toxoplasma secretory proteins during the bradyzoite stage may have important roles in regulating the cyst wall via polysaccharides. Here, we focused on characterizing the hypothetical T. gondii chitinase, chitinase-like protein 1 (TgCLP1). We found that the chitinase-like domain containing TgCLP1 is partially present in the bradyzoite microneme and confirmed, albeit partially, its previous identification in the tachyzoite microneme. Furthermore, although parasites lacking TgCLP1 could convert from tachyzoites to bradyzoites and make an intact cyst wall, they failed to convert from bradyzoites to tachyzoites, indicating that TgCLP1 is necessary for bradyzoite reactivation. Taken together, our findings deepen our understanding of the molecular basis of recrudescence and could contribute to the development of novel strategies for the control of toxoplasmosis.

Combination therapy with oral antiviral and anti-inflammatory drugs improves the efficacy of delayed treatment in a COVID-19 hamster model.
Michihito Sasaki; Tatsuki Sugi; Shun Iida; Yuichiro Hirata; Shinji Kusakabe; Kei Konishi; Yukari Itakura; Koshiro Tabata; Mai Kishimoto; Hiroko Kobayashi; Takuma Ariizumi; Kittiya Intaruck; Haruaki Nobori; Shinsuke Toba; Akihiko Sato; Keita Matsuno; Junya Yamagishi; Tadaki Suzuki; William W Hall; Yasuko Orba; Hirofumi Sawa
EBioMedicine, 99, 104950, 104950, 29 Dec. 2023, [Peer-reviewed], [International Magazine]
English, Scientific journal, BACKGROUND: Pulmonary infection with SARS-CoV-2 stimulates host immune responses and can also result in the progression of dysregulated and critical inflammation. Throughout the pandemic, the management and treatment of COVID-19 has been continuously updated with a range of antiviral drugs and immunomodulators. Monotherapy with oral antivirals has proven to be effective in the treatment of COVID-19. However, treatment should be initiated in the early stages of infection to ensure beneficial therapeutic outcomes, and there is still room for further consideration on therapeutic strategies using antivirals. METHODS: We studied the therapeutic effects of monotherapy with the oral antiviral ensitrelvir or the anti-inflammatory corticosteroid methylprednisolone and combination therapy with ensitrelvir and methylprednisolone in a delayed dosing model of hamsters infected with SARS-CoV-2. FINDINGS: Combination therapy with ensitrelvir and methylprednisolone improved respiratory conditions and reduced the development of pneumonia in hamsters even when the treatment was started after 2 days post-infection. The combination therapy led to a differential histological and transcriptomic pattern in comparison to either of the monotherapies, with reduced lung damage and down-regulation of expression of genes involved in the inflammatory response. Furthermore, we found that the combination treatment is effective in case of infection with either the highly pathogenic delta or circulating omicron variants. INTERPRETATION: Our results demonstrate the advantage of combination therapy with antiviral and corticosteroid drugs in COVID-19 treatment from the perspective of lung pathology and host inflammatory responses. FUNDING: Funding bodies are described in the Acknowledgments section.

Bovine Piroplasma Populations in the Philippines Characterized Using Targeted Amplicon Deep Sequencing.
Eloiza May Galon; Adrian Miki Macalanda; Tatsuki Sugi; Kyoko Hayashida; Naoko Kawai; Taishi Kidaka; Rochelle Haidee Ybañez; Paul Franck Adjou Moumouni; Aaron Edmond Ringo; Hang Li; Shengwei Ji; Junya Yamagishi; Adrian Ybañez; Xuenan Xuan
Microorganisms, 11, 10, 18 Oct. 2023, [Peer-reviewed], [International Magazine]
English, Scientific journal, Molecular assays and capillary electrophoresis sequencing have been used to identify parasites in livestock. The low sample capacity, which increases labor and processing time, is one drawback. Targeted amplicon sequencing (Ampliseq) uses the fast and large sample capacity platform to identify parasites in the target host, overcoming this limitation. DNA was extracted from 162 whole blood samples collected from cattle in three provinces in the Philippines. Using Illumina's Miseq platform, the V4 hypervariable region of the piroplasma 18S rRNA gene was amplified and sequenced. The AMPtk pipeline was used to obtain distinct amplicon sequence variants (ASVs) and the NCBI BLAST non-redundant database was used to assign taxonomy. In total, 95 (58.64%) samples were positive for piroplasma. Using the AMPTk pipeline, 2179 ASVs were obtained. A total of 79 distinct ASVs were obtained after clustering and filtering, which belonged to genera Babesia (n = 58), Theileria (n = 17), Hepatozoon (n = 2), and Sarcocystis (n = 2). The ASV top hits were composed of 10 species: Babesia bovis, B. bigemina, Theileria orientalis, Babesia sp., Hepatozoon canis, Sarcocystis cruzi, T. annulata, T. equi, T. mutans, and Theileria sp. Thung Song. The results generated in this study demonstrated the applicability of Ampliseq in detecting piroplasmid parasites infecting cattle in the Philippines.

Field-deployable multiplex detection method of SARS-CoV-2 and influenza virus using loop-mediated isothermal amplification and DNA chromatography.
Kyoko Hayashida; Alejandro Garcia; Lavel Chinyama Moonga; Tatsuki Sugi; Kodera Takuya; Mitsuo Kawase; Fumihiro Kodama; Atsushi Nagasaka; Nobuhisa Ishiguro; Ayato Takada; Masahiro Kajihara; Naganori Nao; Masashi Shingai; Hiroshi Kida; Yasuhiko Suzuki; William W Hall; Hirofumi Sawa; Junya Yamagishi
PloS one, 18, 5, e0285861, 2023, [Peer-reviewed], [International Magazine]
English, Scientific journal, A novel multiplex loop-mediated isothermal amplification (LAMP) method combined with DNA chromatography was developed for the simultaneous detection of three important respiratory disease-causing viruses: severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus, and influenza B virus. Amplification was performed at a constant temperature, and a positive result was confirmed by a visible colored band. An in-house drying protocol with trehalose was used to prepare the dried format multiplex LAMP test. Using this dried multiplex LAMP test, the analytical sensitivity was determined to be 100 copies for each viral target and 100-1000 copies for the simultaneous detection of mixed targets. The multiplex LAMP system was validated using clinical COVID-19 specimens and compared with the real-time qRT-PCR method as a reference test. The determined sensitivity of the multiplex LAMP system for SARS-CoV-2 was 71% (95% CI: 0.62-0.79) for cycle threshold (Ct) ≤ 35 samples and 61% (95% CI: 0.53-0.69) for Ct ≤40 samples. The specificity was 99% (95%CI: 0.92-1.00) for Ct ≤35 samples and 100% (95%CI: 0.92-1.00) for the Ct ≤40 samples. The developed simple, rapid, low-cost, and laboratory-free multiplex LAMP system for the two major important respiratory viral diseases, COVID-19 and influenza, is a promising field-deployable diagnosis tool for the possible future 'twindemic, ' especially in resource-limited settings.

Circular Whole-Transcriptome Amplification (cWTA) and mNGS Screening Enhanced by a Group Testing Algorithm (mEGA) Enable High-Throughput and Comprehensive Virus Identification.
Patrick Reteng; Linh Nguyen Thuy; Mizanur Rahman; Ana Maria Bispo de Filippis; Kyoko Hayashida; Tatsuki Sugi; Gabriel Gonzalez; William W Hall; Lan Anh Nguyen Thi; Junya Yamagishi
mSphere, e0033222, 25 Aug. 2022, [Peer-reviewed], [International Magazine]
English, Scientific journal, Metagenomic next-generation sequencing (mNGS) offers a hypothesis-free approach for pathogen detection, but its applicability in clinical diagnosis, in addition to other factors, remains limited due to complicated library construction. The present study describes a PCR-free isothermal workflow for mNGS targeting RNA, based on a multiple displacement amplification, termed circular whole-transcriptome amplification (cWTA), as the template is circularized before amplification. The cWTA approach was validated with clinical samples and nanopore sequencing. Reads homologous to dengue virus 2 and chikungunya virus were detected in clinical samples from Bangladesh and Brazil, respectively. In addition, the practicality of a high-throughput detection system that combines mNGS and a group testing algorithm termed mNGS screening enhanced by a group testing algorithm (mEGA) was established. This approach enabled significant library size reduction while permitting trackability between samples and diagnostic results. Serum samples of patients with undifferentiated febrile illnesses from Vietnam (n = 43) were also amplified with cWTA, divided into 11 pools, processed for library construction, and sequenced. Dengue virus 2, hepatitis B virus, and parvovirus B19 were successfully detected without prior knowledge of their existence. Collectively, cWTA with the nanopore platform opens the possibility of hypothesis-free on-site comprehensive pathogen diagnosis, while mEGA contributes to the scaling up of sample throughput. IMPORTANCE Given the breadth of pathogens that cause infections, a single approach that can detect a wide range of pathogens is ideal but is impractical due to the available tests being highly specific to a certain pathogen. Recent developments in sequencing technology have introduced mNGS as an alternative that provides detection of a wide-range of pathogens by detecting the presence of their nucleic acids in the sample. However, sequencing library preparation is still a bottleneck, as it is complicated, costly, and time-consuming. In our studies, alternative approaches to optimize library construction for mNGS were developed. This included isothermal nucleic acid amplification and expansion of sample throughput with a group testing algorithm. These methods can improve the utilization of mNGS as a diagnostic tool and can serve as a high-throughput screening system aiding infectious disease surveillance.

TSS-seq of Toxoplasma gondii sporozoites revealed a novel motif in stage-specific promoters.
Taishi Kidaka; Tatsuki Sugi; Kyoko Hayashida; Yutaka Suzuki; Xuenan Xuan; Jitender P Dubey; Junya Yamagishi
Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases, 98, 105213, 105213, 15 Jan. 2022, [Peer-reviewed], [International Magazine]
English, Scientific journal, Toxoplasma gondii is one of the most common zoonotic protozoan parasites. It has three major infectious stages: rapidly multiplying tachyzoites (Tz), slowly replicating bradyzoites (Bz) and a resting/free-living stage, sporozoites (Sz). The regulatory mechanisms governing stage-specific gene expression are not fully understood. Few transcriptional start sites (TSS) are known for Sz. In this study, we obtained TSS of Sz using an oligo-capping method and RNA-seq analysis. We identified 1,043,503 TSS in the Sz transcriptome. These defined 38,973 TSS clusters, of which, 11,925 were expressed in Sz and 1535 TSS differentially expressed in Sz. Based on these data, we defined promoter regions and novel sporozoite stage-specific motifs using MEME. TGTANNTACA was distributed around -55 to -75 regions from each TSS. Interestingly, the same motif was reported in another apicomplexan, Plasmodium berghei, as a cis-element of female-specific gametocyte genes, implying the presence of common regulatory machinery. Further comparative analysis should better define the distribution and function of these elements in other members of this important parasitic phylum.

COVID-19 Whole-Genome Resequencing with Redundant Tiling PCR and Subtract-Based Amplicon Normalization Successfully Characterized SARS-CoV-2 Variants in Clinical Specimens.
Tatsuki Sugi; Mizanur Rahman; Rummana Rahim; Abu Hasan; Naoko Kawai; Kyoko Hayashida; Junya Yamagishi
Interdisciplinary perspectives on infectious diseases, 2022, 2109641, 2109641, 2022, [Peer-reviewed], [Lead author], [International Magazine]
English, Scientific journal, With an increasing number of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) sequences gathered worldwide, we recognize that deletion mutants and nucleotide substitutions that may affect whole-genome sequencing are accumulating. Here, we propose an additional strategy for tiling PCR for whole-genome resequencing, which can make the pipeline robust for mutations at the primer annealing site by a redundant amplicon scheme. We further demonstrated that subtracting overrepresented amplicons from the multiplex PCR products reduced the bias of the next-generation sequencing (NGS) library, resulting in decreasing required sequencing reads per sample. We applied this sequencing strategy to clinical specimens collected in Bangladesh. More than 80% out of the 304 samples were successfully sequenced. Less than 5% were ambiguous nucleotides, and several known variants were detected. With the additional strategies presented here, we believe that whole-genome resequencing of SARS-CoV-2 from clinical samples can be optimized.

Single Cell Transcriptomes of In Vitro Bradyzoite Infected Cells Reveals Toxoplasma gondii Stage Dependent Host Cell Alterations.
Tatsuki Sugi; Tadakimi Tomita; Taishi Kidaka; Naoko Kawai; Kyoko Hayashida; Louis M Weiss; Junya Yamagishi
Frontiers in cellular and infection microbiology, 12, 848693, 848693, 2022, [Peer-reviewed], [Lead author], [International Magazine]
English, Scientific journal, Toxoplasma gondii bradyzoites establish chronic infections within their host cells. Recent studies have demonstrated that several parasite effector proteins are translocated to host cells during the bradyzoite stage of chronic infection. To understand the interaction between host cells and bradyzoites at the transcriptomic landscape level, we utilized single-cell RNA-sequencing (scRNA-Seq) to characterize the bradyzoite-induced host cell response. Distinct gene expression profiles were observed in infected host, cells with low parasite mapped reads, and mock (non-exposed) control cells. Gene set enrichment analysis showed that c-Myc and NF-κB signaling and energy metabolic pathways were upregulated by infection. Type I and II interferon response pathways were upregulated in cells with low parasite mapped reads compared to the non-exposed host control cells, and this upregulation effect was reversed in infected cells. Differences were observed in the host cells depending on the differentiation status of the parasites, as determined by BAG1 and SAG1 expression. NF-κB, inflammatory response pathways, and IFN-γ response pathways were downregulated in host cells containing T. gondii BAG1+/SAG1-, whereas this downregulation effect was reversed in case of T. gondii BAG1-/SAG1+. We also identified two distinct host cell subsets that contained T. gondii BAG1+/SAG1-, one of which displayed distinct transcriptomes with upregulated c-Myc expression. Overall, these data clearly demonstrate that host cell transcriptional alteration by bradyzoite infection is different from that of tachyzoite infection, indicating fine-tuning of the host immune response.

SARS-CoV-2 Genome Sequences, Including One with an ORF7a Deletion, Obtained from Patients in Bangladesh.
Mizanur Rahman; Rummana Rahim; Abu Hasan; Naoko Kawai; Lavel Chinyama Moonga; Tatsuki Sugi; Kyoko Hayashida; Junya Yamagishi
Microbiology resource announcements, 10, 49, e0076421, 09 Dec. 2021, [Peer-reviewed], [International Magazine]
English, Scientific journal, Genomic sequences from a complete SARS-CoV-2 open reading frame (ORF) were obtained from 24 patients diagnosed in May 2020 in Dhaka, Bangladesh. All sequences belonged to clade 20A or 20B, and none were variants of concern. Interestingly, one sequence showed a 161-nucleotide deletion in ORF7a.

Toxoplasma gondii Matrix Antigen 1 Is a Secreted Immunomodulatory Effector
Tadakimi Tomita; Debanjan Mukhopadhyay; Bing Han; Rama Yakubu; Vincent Tu; Joshua Mayoral; Tatsuki Sugi; Yanfen Ma; Jeroen P. J. Saeij; Louis M. Weiss
mBio, 12, 3, e00603-21, American Society for Microbiology, 07 Jul. 2021, [Peer-reviewed]
Scientific journal, Toxoplasma gondii
is an Apicomplexan that infects a third of humans, causing encephalitis in AIDS patients and intellectual disabilities in congenitally infected patients. We determined that one of the cyst matrix proteins, MAG1, which had been thought to be an innate structural protein, can be secreted into the host cell and suppress the host immune reaction.

Nullscript inhibits Cryptosporidium and Toxoplasma growth
Fumi Murakoshi; Hironori Bando; Tatsuki Sugi; Oluyomi Stephen Adeyemi; Motohiro Nonaka; Takaaki Nakaya; Kentaro Kato
International Journal for Parasitology: Drugs and Drug Resistance, 14, 159, 166, Elsevier BV, Oct. 2020, [Peer-reviewed]
Scientific journal

Imidazole derivatives as antiparasitic agents and use of molecular modeling to investigate the structure-activity relationship
Oluyomi Stephen Adeyemi; Abiodun Omokehinde Eseola; Winfried Plass; Olubunmi Atolani; Tatsuki Sugi; Yongmei Han; Gaber El-saber Batiha; Kentaro Kato; Oluwakemi Josephine Awakanl; Tomilola Debby Olaolu; Charles Obiora Nwonuma; Omokolade Alejolowo; Akinyomade Owolabi; Damilare Rotimi; Omowumi Titilola Kayode
PARASITOLOGY RESEARCH, 119, 6, 1925, 1941, Jun. 2020, [Peer-reviewed]
English, Scientific journal

MAG2, a Toxoplasma gondii Bradyzoite Stage-Specific Cyst Matrix Protein.
Vincent Tu; Joshua Mayoral; Rama R Yakubu; Tadakimi Tomita; Tatsuki Sugi; Bing Han; Tere Williams; Yanfen Ma; Louis M Weiss
mSphere, 5, 1, e00100-20, 26 Feb. 2020, [Peer-reviewed], [International Magazine]
English, Scientific journal, Toxoplasma gondii causes a chronic infection that affects a significant portion of the world's population, and this latent infection is the source of reactivation of toxoplasmosis. An attribute of the slowly growing bradyzoite stage of the parasite is the formation of a cyst within infected cells, allowing the parasite to escape the host's immune response. In this study, a new bradyzoite cyst matrix antigen (MAG) was identified through a hybridoma library screen. This cyst matrix antigen, matrix antigen 2 (MAG2), contains 14 tandem repeats consisting of acidic, basic, and proline residues. Immunoblotting revealed that MAG2 migrates at a level higher than its predicted molecular weight, and computational analysis showed that the structure of MAG2 is highly disordered. Cell fractionation studies indicated that MAG2 was associated with both insoluble and soluble cyst matrix material, suggesting that it interacts with the intracyst network (ICN). Examination of the kinetics of MAG2 within the cyst matrix using fluorescence recovery after photobleaching (FRAP) demonstrated that MAG2 does not readily diffuse within the cyst matrix. Kinetic studies of MAG1 demonstrated that this protein has different diffusion kinetics in tachyzoite and bradyzoite vacuoles and that its mobility is not altered in the absence of MAG2. In addition, deletion of MAG2 does not influence growth, cystogenesis, or cyst morphology.IMPORTANCE This report expands on the list of characterized Toxoplasma gondii cyst matrix proteins. Using fluorescence recovery after photobleaching (FRAP), we have shown that matrix proteins within the cyst matrix are not mainly in a mobile state, providing further evidence of how proteins behave within the cyst matrix. Understanding the proteins expressed during the bradyzoite stage of the parasite reveals how the parasite functions during chronic infection.

Validation of a new serum granulocyte-macrophage colony-stimulating factor autoantibody testing kit
Koh Nakata; Tatsuki Sugi; Keiko Kuroda; Kazutaka Yoshizawa; Toshinori Takada; Ryushi Tazawa; Takahiro Ueda; Ami Aoki; Mitsuhiro Abe; Koichiro Tatsumi; Ryosuke Eda; Shotaro Kondoh; Konosuke Morimoto; Takeshi Tanaka; Etsuro Yamaguchi; Ayumu Takahashi; Miku Oda; Haruyuki Ishii; Shinyu Izumi; Haruhito Sugiyama; Atsushi Nakagawa; Keisuke Tomii; Masaru Suzuki; Satoshi Konno; Shinya Ohkouchi; Taizou Hirano; Tomohiro Handa; Toyohiro Hirai; Yoshikazu Inoue; Toru Arai; Katsuaki Asakawa; Takuro Sakagami; Takahiro Tanaka; Ayako Mikami; Nobutaka Kitamura
ERJ OPEN RESEARCH, 6, 1, Jan. 2020, [Peer-reviewed]
English, Scientific journal

The Toxoplasma gondii Cyst Wall Interactome
Vincent Tu; Tadakimi Tomita; Tatsuki Sugi; Joshua Mayoral; Bing Han; Rama R. Yakubu; Tere Williams; Aline Horta; Yanfen Ma; Louis M. Weiss
MBIO, 11, 1, Jan. 2020, [Peer-reviewed]
English, Scientific journal

Enrichment and Proteomic Characterization of the Cyst Wall from In Vitro Toxoplasma gondii Cysts
Vincent Tu; Joshua Mayoral; Tatsuki Sugi; Tadakimi Tomita; Bing Han; Yan Fen Ma; Louis M. Weiss
MBIO, 10, 2, Mar. 2019, [Peer-reviewed]
English, Scientific journal

Nanoparticles show potential to retard bradyzoites in vitro formation of Toxoplasma gondii
Oluyomi Stephen Adeyemi; Yuho Murata; Tatsuki Sugi; Yongmei Han; Kentaro Kato
FOLIA PARASITOLOGICA, 66, Feb. 2019, [Peer-reviewed]
English, Scientific journal

Exploring Amino Acid-Capped Nanoparticles for Selective Anti-Parasitic Action and Improved Host Biocompatibility
Oluyomi Stephen Adeyemi; Yuho Murata; Tatsuki Sugi; Yongmei Han; Kentaro Kato
JOURNAL OF BIOMEDICAL NANOTECHNOLOGY, 14, 5, 847, 867, May 2018, [Peer-reviewed]
English, Scientific journal

Toxoplasma gondii RON4 binds to heparan sulfate on the host cell surface
Hitoshi Takemae; Kyousuke Kobayashi; Tatsuki Sugi; Yongmei Han; Haiyan Gong; Akiko Ishiwa; Frances C. Recuenco; Fumi Murakoshi; Ryo Takano; Yuho Murata; Kisaburo Nagamune; Taisuke Horimoto; Hiroomi Akashi; Kentaro Kato
PARASITOLOGY INTERNATIONAL, 67, 2, 123, 130, Apr. 2018, [Peer-reviewed]
English, Scientific journal

Screening of chemical compound libraries identified new anti-Toxoplasma gondii agents
Oluyomi Stephen Adeyemi; Tatsuki Sugi; Yongmei Han; Kentaro Kato
PARASITOLOGY RESEARCH, 117, 2, 355, 363, Feb. 2018, [Peer-reviewed]
English, Scientific journal

Assessment of the growth inhibitory effect of gellan sulfate in rodent malaria in vivo
Frances C. Recuenco; Ryo Takano; Tatsuki Sugi; Hitoshi Takemae; Fumi Murakoshi; Akiko Ishiwa; Atsuko Inomata; Yukiko Enomoto-Rogers; Noreen Grace V. Fundador; Tadahisa Iwata; Taisuke Horimoto; Hiroomi Akashi; Kentaro Kato
JAPANESE JOURNAL OF VETERINARY RESEARCH, 65, 4, 207, 212, Nov. 2017, [Peer-reviewed]
English, Scientific journal

Toxoplasma gondii Requires Glycogen Phosphorylase for Balancing Amylopectin Storage and for Efficient Production of Brain Cysts
Tatsuki Sugi; Vincent Tu; Yanfen Ma; Tadakimi Tomita; Louis M. Weiss
MBIO, 8, 4, Jul. 2017, [Peer-reviewed], [Lead author]
English, Scientific journal

Identification of compounds that suppress Toxoplasma gondii tachyzoites and bradyzoites
Yuho Murata; Tatsuki Sugi; Louis M. Weiss; Kentaro Kato
PLOS ONE, 12, 6, Jun. 2017, [Peer-reviewed], [Lead author]
English, Scientific journal

The role of microsporidian polar tube protein 4 (PTP4) in host cell infection
Bing Han; Valerie Polonais; Tatsuki Sugi; Rama Yakubu; Peter M. Takvorian; Ann Cali; Keith Maier; Mengxian Long; Matthew Levy; Herbert B. Tanowitz; Guoqing Pan; Frederic Delbac; Zeyang Zhou; Louis M. Weiss
PLOS PATHOGENS, 13, 4, Apr. 2017, [Peer-reviewed]
English, Scientific journal

Inorganic nanoparticles kill Toxoplasma gondii via changes in redox status and mitochondrial membrane potential
Oluyomi Stephen Adeyemi; Yuho Murata; Tatsuki Sugi; Kentaro Kato
INTERNATIONAL JOURNAL OF NANOMEDICINE, 12, 1647, 1661, 2017, [Peer-reviewed]
English, Scientific journal

Making Home Sweet and Sturdy: Toxoplasma gondii ppGalNAc-Ts Glycosylate in Hierarchical Order and Confer Cyst Wall Rigidity
Tadakimi Tomita; Tatsuki Sugi; Rama Yakubu; Vincent Tu; Yanfen Ma; Louis M. Weiss
MBIO, 8, 1, Jan. 2017, [Peer-reviewed]
English, Scientific journal

Pull-down method to access the cell surface receptor for Toxoplasma gondii
Haiyan Gong; Kyousuke Kobayashi; Tatsuki Sugi; Hitoshi Takemae; Taisuke Horimoto; Xuenan Xuan; Hiroomi Akashi; Kentaro Kato
PARASITOLOGY INTERNATIONAL, 65, 5, 514, 515, Oct. 2016, [Peer-reviewed]
English, Scientific journal

An improved method for introducing site-directed point mutation into the Toxoplasma gondii genome using CRISPR/Cas9
Tatsuki Sugi; Kentaro Kato; Louis M. Weiss
PARASITOLOGY INTERNATIONAL, 65, 5, 558, 562, Oct. 2016, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal

Characterization of a Toxoplasma gondii calcium calmodulin-dependent protein kinase homolog
Kentaro Kato; Tatsuki Sugi; Hitoshi Takemae; Ryo Takano; Haiyan Gong; Akiko Ishiwa; Taisuke Horimoto; Hiroomi Akashi
PARASITES & VECTORS, 9, Jul. 2016, [Peer-reviewed]
English, Scientific journal

Toxoplasma gondii Cyclic AMP-Dependent Protein Kinase Subunit 3 Is Involved in the Switch from Tachyzoite to Bradyzoite Development
Tatsuki Sugi; Yan Fen Ma; Tadakimi Tomita; Fumi Murakoshi; Michael S. Eaton; Rama Yakubu; Bing Han; Vincent Tu; Kentaro Kato; Shin-Ichiro Kawazu; Nishith Gupta; Elena S. Suvorova; Michael W. White; Kami Kim; Louis M. Weiss
MBIO, 7, 3, May 2016, [Peer-reviewed], [Lead author]
English, Scientific journal

Heparin interacts with elongation factor 1 alpha of Cryptosporidium parvum and inhibits invasion
Atsuko Inomata; Fumi Murakoshi; Akiko Ishiwa; Ryo Takano; Hitoshi Takemae; Tatsuki Sugi; Frances Cagayat Recuenco; Taisuke Horimoto; Kentaro Kato
SCIENTIFIC REPORTS, 5, Jul. 2015, [Peer-reviewed]
English, Scientific journal

A single mutation in the gatekeeper residue in TgMAPKL-1 restores the inhibitory effect of a bumped kinase inhibitor on the cell cycle
Tatsuki Sugi; Shin-ichiro Kawazu; Taisuke Horimoto; Kentaro Kato
INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE, 5, 1, 1, 8, Apr. 2015, [Peer-reviewed], [Lead author]
English, Scientific journal

Lambda-carrageenan treatment exacerbates the severity of cerebral malaria caused by Plasmodium berghei ANKA in BALB/c mice
Frances C. Recuenco; Ryo Takano; Shiori Chiba; Tatsuki Sugi; Hitoshi Takemae; Fumi Murakoshi; Akiko Ishiwa; Atsuko Inomata; Taisuke Horimoto; Yoshiyasu Kobayashi; Noriyuki Horiuchi; Kentaro Kato
MALARIA JOURNAL, 13, Dec. 2014, [Peer-reviewed]
English, Scientific journal

Akabane Virus Utilizes Alternative Endocytic Pathways to Entry into Mammalian Cell Lines
Norasuthi Bangphoomi; Akiko Takenaka-Uema; Tatsuki Sugi; Kentaro Kato; Hiroomi Akashi; Taisuke Horimoto
JOURNAL OF VETERINARY MEDICAL SCIENCE, 76, 11, 1471, 1478, Nov. 2014, [Peer-reviewed]
English, Scientific journal

Microplate assay for screening Toxoplasma gondii bradyzoite differentiation with DUAL luciferase assay
Tatsuki Sugi; Tatsunori Masatani; Fumi Murakoshi; Shin-Ichiro Kawazu; Kentaro Kato
ANALYTICAL BIOCHEMISTRY, 464, 9, 11, Nov. 2014, [Peer-reviewed], [Lead author]
English, Scientific journal

Analyses of the binding between Theileria orientalis major piroplasm surface proteins and bovine red blood cells
H. Takemae; T. Sugi; K. Kobayashi; F. Murakoshi; F. C. Recuenco; A. Ishiwa; A. Inomata; T. Horimoto; N. Yokoyama; K. Kato
VETERINARY RECORD, 175, 6, 149, Aug. 2014, [Peer-reviewed]
English, Scientific journal

Interaction between Theileria orientalis 23-kDa piroplasm membrane protein and heparin
Hitoshi Takemae; Tatsuki Sugi; Kyousuke Kobayashi; Fumi Murakoshi; Frances C. Recuenco; Akiko Ishiwa; Atsuko Inomata; Taisuke Horimoto; Naoaki Yokoyama; Kentaro Kato
JAPANESE JOURNAL OF VETERINARY RESEARCH, 62, 1-2, 17, 24, May 2014, [Peer-reviewed]
English, Scientific journal

Characterization and binding analysis of a microneme adhesive repeat domain-containing protein from Toxoplasma gondii
Haiyan Gong; Kyousuke Kobayashi; Tatsuki Sugi; Hitoshi Takemae; Akiko Ishiwa; Frances C. Recuenco; Fumi Murakoshi; Xuenan Xuan; Taisuke Horimoto; Hiroomi Akashi; Kentaro Kato
PARASITOLOGY INTERNATIONAL, 63, 2, 381, 388, Apr. 2014, [Peer-reviewed]
English, Scientific journal

Gellan sulfate inhibits Plasmodium falciparum growth and invasion of red blood cells in vitro
Frances Cagayat Recuenco; Kyousuke Kobayashi; Akiko Ishiwa; Yukiko Enomoto-Rogers; Noreen Grace V. Fundador; Tatsuki Sugi; Hitoshi Takemae; Tatsuya Iwanaga; Fumi Murakoshi; Haiyan Gong; Atsuko Inomata; Taisuke Horimoto; Tadahisa Iwata; Kentaro Kato
SCIENTIFIC REPORTS, 4, Apr. 2014, [Peer-reviewed]
English, Scientific journal

Effects of dextran sulfates on the acute infection and growth stages of Toxoplasma gondii
Akiko Ishiwa; Kyousuke Kobayashi; Hitoshi Takemae; Tatsuki Sugi; Haiyan Gong; Frances C. Recuenco; Fumi Murakoshi; Atsuko Inomata; Taisuke Horimoto; Kentaro Kato
PARASITOLOGY RESEARCH, 112, 12, 4169, 4176, Dec. 2013, [Peer-reviewed]
English, Scientific journal

Identification of mutations in TgMAPK1 of Toxoplasma gondii conferring resistance to 1NM-PP1
Tatsuki Sugi; Kyousuke Kobayashi; Hitoshi Takemae; Haiyan Gong; Akiko Ishiwa; Fumi Murakoshi; Frances C. Recuenco; Tatsuya Iwanaga; Taisuke Horimoto; Hiroomi Akashi; Kentaro Kato
INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE, 3, 93, 101, Dec. 2013, [Peer-reviewed], [Lead author]
English, Scientific journal

Analyses of Interactions Between Heparin and the Apical Surface Proteins of Plasmodium falciparum
Kyousuke Kobayashi; Ryo Takano; Hitoshi Takemae; Tatsuki Sugi; Akiko Ishiwa; Haiyan Gong; Frances C. Recuenco; Tatsuya Iwanaga; Taisuke Horimoto; Hiroomi Akashi; Kentaro Kato
SCIENTIFIC REPORTS, 3, Nov. 2013, [Peer-reviewed]
English, Scientific journal

Characterization of the interaction between Toxoplasma gondii rhoptry neck protein 4 and host cellular beta-tubulin
Hitoshi Takemae; Tatsuki Sugi; Kyousuke Kobayashi; Haiyan Gong; Akiko Ishiwa; Frances C. Recuenco; Fumi Murakoshi; Tatsuya Iwanaga; Atsuko Inomata; Taisuke Horimoto; Hiroomi Akashi; Kentaro Kato
SCIENTIFIC REPORTS, 3, Nov. 2013, [Peer-reviewed]
English, Scientific journal

Characterization of Plasmodium falciparum cdc2-related kinase and the effects of a CDK inhibitor on the parasites in erythrocytic schizogony
Tatsuya Iwanaga; Tatsuki Sugi; Kyousuke Kobayashi; Hitoshi Takemae; Haiyan Gong; Akiko Ishiwa; Fumi Murakoshi; Frances C. Recuenco; Taisuke Horimoto; Hiroomi Akashi; Kentaro Kato
PARASITOLOGY INTERNATIONAL, 62, 5, 423, 430, Oct. 2013, [Peer-reviewed]
English, Scientific journal

Roles of Apicomplexan protein kinases at each life cycle stage
Kentaro Kato; Tatsuki Sugi; Tatsuya Iwanaga
PARASITOLOGY INTERNATIONAL, 61, 2, 224, 234, Jun. 2012, [Peer-reviewed]
English

A Novel PAN/Apple Domain-Containing Protein from Toxoplasma gondii: Characterization and Receptor Identification
Haiyan Gong; Kyousuke Kobayashi; Tatsuki Sugi; Hitoshi Takemae; Hitomi Kurokawa; Taisuke Horimoto; Hiroomi Akashi; Kentaro Kato
PLOS ONE, 7, 1, Jan. 2012, [Peer-reviewed]
English, Scientific journal

1NM-PP1 Treatment of Mice Infected with Toxoplasma gondii
Tatsuki Sugi; Kentaro Kato; Kyousuke Kobayashi; Hitomi Kurokawa; Hitoshi Takemae; Haiyan Gong; Frances C. Recuenco; Tatsuya Iwanaga; Taisuke Horimoto; Hiroomi Akashi
JOURNAL OF VETERINARY MEDICAL SCIENCE, 73, 10, 1377, 1379, Oct. 2011, [Peer-reviewed], [Lead author]
English, Scientific journal

Identification of Toxoplasma gondii cAMP Dependent Protein Kinase and Its Role in the Tachyzoite Growth
Hitomi Kurokawa; Kentaro Kato; Tatsuya Iwanaga; Tatsuki Sugi; Atsushi Sudo; Kyousuke Kobayashi; Haiyan Gong; Hitoshi Takemae; Frances C. Recuenco; Taisuke Horimoto; Hiroomi Akashi
PLOS ONE, 6, 7, Jul. 2011, [Peer-reviewed]
English, Scientific journal

Use of the Kinase Inhibitor Analog 1NM-PP1 Reveals a Role for Toxoplasma gondii CDPK1 in the Invasion Step
Tatsuki Sugi; Kentaro Kato; Kyosuke Kobayashi; Shumpei Watanabe; Hitomi Kurokawa; Haiyan Gong; Kishor Pandey; Hitoshi Takemae; Hiroomi Akashi
EUKARYOTIC CELL, 9, 4, 667, 670, Apr. 2010, [Peer-reviewed], [Lead author]
English, Scientific journal

Plasmodium falciparum BAEBL Binds to Heparan Sulfate Proteoglycans on the Human Erythrocyte Surface
Kyousuke Kobayashi; Kentaro Kato; Tatsuki Sugi; Hitoshi Takemae; Kishor Pandey; Haiyan Gong; Yukinobu Tohya; Hiroomi Akashi
JOURNAL OF BIOLOGICAL CHEMISTRY, 285, 3, 1716, 1725, Jan. 2010, [Peer-reviewed]
English, Scientific journal

Characterization of Plasmodium falciparum calcium-dependent protein kinase 4
Kentaro Kato; Atsushi Sudo; Kyousuke Kobayashi; Tatsuki Sugi; Yukinobu Tohya; Hiroomi Akashi
PARASITOLOGY INTERNATIONAL, 58, 4, 394, 400, Dec. 2009, [Peer-reviewed]
English, Scientific journal

Molecular analyses of Toxoplasma gondii calmodulin-like domain protein kinase isoform 3
Tatsuki Sugi; Kentaro Kato; Kyousuke Kobayashi; Kishor Pandey; Hitoshi Takemae; Hitomi Kurokawa; Yukinobu Tohya; Hiroomi Akashi
PARASITOLOGY INTERNATIONAL, 58, 4, 416, 423, Dec. 2009, [Peer-reviewed], [Lead author]
English, Scientific journal

Application of retrovirus-mediated expression cloning for receptor screening of a parasite
Kyousuke Kobayashi; Kentaro Kato; Tatsuki Sugi; Daisuke Yamane; Masayuki Shimojima; Yukinobu Tohya; Hiroomi Akashi
ANALYTICAL BIOCHEMISTRY, 389, 1, 80, 82, Jun. 2009, [Peer-reviewed]
English

新規変異を人為導入された狂犬病生ワクチン候補株の弱毒性状の安定性の検討
長繩優佳; 山下佳葉子; 泉郁輝; 高橋まほ; 佐々木道仁; 山岸潤也; 杉達紀; 正谷達謄; 伊藤直人; 正谷達謄; 伊藤直人; 正谷達謄; 伊藤直人, 日本獣医学会学術集会講演要旨集, 167th, 2024

Characterization of SARS-CoV-2 with mutations in viral nsp5 gene
佐々木道仁; 佐々木道仁; 板倉友香里; 田畑耕史郎; 日下部伸治; 日下部伸治; 小西慧; 小西慧; 杉達紀; 山岸潤也; 山岸潤也; 小林広子; 有泉拓馬; 川口虹穂; 佐藤彰彦; 佐藤彰彦; 佐藤彰彦; 澤洋文; 澤洋文; 澤洋文; 大場靖子; 大場靖子; 大場靖子, 日本ウイルス学会学術集会プログラム・予稿集(Web), 71st, 2024

Nsp5遺伝子に変異を有するSARS-CoV-2の抗ウイルス薬感受性とウイルス性状の解析
佐々木道仁; 佐々木道仁; 板倉友香里; 田畑耕史郎; 日下部伸治; 日下部伸治; 小西慧; 小西慧; 杉達紀; 山岸潤也; 山岸潤也; 川口虹穂; 藤井英里; 佐藤彰彦; 佐藤彰彦; 佐藤彰彦; 澤洋文; 澤洋文; 澤洋文; 大場靖子; 大場靖子; 大場靖子, 日本分子生物学会年会プログラム・要旨集(Web), 47th, 2024

Investigating the utility of novel attenuated mutations to improve the safety of live rabies vaccines.
長縄優佳; 山下佳葉子; 正谷達謄; 正谷達謄; 正谷達謄; 泉郁輝; 藤井祐至; 岡島美鈴; 西山祥子; 高橋まほ; 佐々木道仁; 山岸潤也; 杉達紀; 伊藤直人; 伊藤直人; 伊藤直人, 日本ウイルス学会学術集会プログラム・予稿集(Web), 71st, 2024

Collaboration in COVID-19 epidemiology in Zambia and Gabon
山岸潤也; 邱永晋; 梶原将大; 林田京子; 杉達紀; 澤洋文; 阿部遥; 安田二郎, 日本ウイルス学会学術集会プログラム・予稿集(Web), 69th, 2022

Modulation of host HIF-1α activity and the tryptophan pathway contributes to the anti-Toxoplasma gondii potential of nanoparticles
Adeyemi Oluyomi Stephen; Murata Yuho; Sugi Tatsuki; Han Yongmei; Kato Kentaro, Biochemistry and Biophysics Reports, 11, 84, 92, 2017
BackgroundToxoplasmosis constitutes a large global burden that is further exacerbated by the shortcomings of available therapeutic options, thus underscoring the urgent need for better anti-Toxoplasma gondii therapy or strategies. Recently, we showed that the anti-parasitic action of inorganic nanoparticles (NPs) could, in part, be due to changes in redox status as well as in the parasite mitochondrial membrane potential. MethodsIn the present study, we explored the in vitro mode of action of the anti-T. gondii effect of NPs by evaluating the contributions of host cellular processes, including the tryptophan pathway and hypoxia-inducing factor activity. NPs, at concentrations ranging from 0.01 to 200 μg/ml were screened for anti-parasitic activity. Sulfadiazine and/or pyrimethamine served as positive controls.ResultsWe found that interplay among multiple host cellular processes, including HIF-1α activity, indoleamine 2,3-dioxygenase activity, and to a larger extent the tryptophan pathway, contribute to the anti-parasitic action of NPs. Conclusion To our knowledge, this is the first study to demonstrate an effect of NPs on the tryptophan and/or kynurenine pathway. General significanceOur findings deepen our understanding of the mechanism of action of NPs and suggest that modulation of the host nutrient pool may represent a viable approach to the development of new and effective anti-parasitic agents., Elsevier B.V., English

DUAL‐LUCIFERASEを利用したトキソプラズマ潜伏感染の高効率評価系
杉達紀; 正谷達謄; 村越ふみ; 河津信一郎; 加藤健太郎, 日本獣医学会学術集会講演要旨集, 157th, 357, 357, 11 Aug. 2014
(公社)日本獣医学会, Japanese

小型ピロプラズマ主要膜抗原と結合する宿主因子の解析
竹前等; 杉達紀; 杉達紀; 高野量; 村越ふみ; RECUENCO Frances; RECUENCO Frances; 石和玲子; 石和玲子; 堀本泰介; 横山直明; 加藤健太郎; 加藤健太郎, 日本獣医学会学術集会講演要旨集, 156th, 2013

Toxoplasma gondii PKA regulatory subunitの機能解析
黒川瞳; 加藤健太郎; 岩永達也; 杉達紀; 首藤篤史; 小林郷介; ゴン海燕; 竹前等; 堀本泰介; 明石博臣, 日本獣医学会学術集会講演要旨集, 152nd, 2011

トキソプラズマ原虫のcAMP依存性プロテインキナーゼの機能解析
黒川瞳; 加藤健太郎; 首藤篤史; 小林郷介; 杉達紀; 竹前等; ゴン海燕; 明石博臣, 日本獣医学会学術集会講演要旨集, 150th, 2010

Plasmodium falciparum BAEBLとヘパラン硫酸プロテオグリカンの相互作用に関する研究
小林郷介; 加藤健太郎; 首藤篤史; 杉達紀; 下島昌幸; 遠矢幸伸; 明石博臣, 日本寄生虫学会大会プログラム・抄録集, 78th, 2009

宿主移動に伴うマラリア原虫プロテインキナーゼPfCDPK4の機能変化
加藤健太郎; 首藤篤史; 小林郷介; 杉達紀; 遠矢幸伸; 明石博臣, 日本獣医学会学術集会講演要旨集, 146th, 2008

Plasmodium falciparum BAEBLは赤血球表面のヘパラン硫酸プロテオグリカンに結合する
小林郷介; 加藤健太郎; 首藤篤史; 杉達紀; 下島昌幸; 遠矢幸伸; 明石博臣, 日本獣医学会学術集会講演要旨集, 146th, 2008

熱帯熱マラリア原虫プロテインキナーゼPfCDPK4のリン酸化の感染環における役割
加藤健太郎; 首藤篤史; 小林郷介; 杉達紀; 遠矢幸紳; 明石博臣, 日本寄生虫学会大会プログラム・抄録集, 77th, 2008

Single Cell transcriptome reveals a host cell alteration by Toxoplasma gondii in vitro bradyzoite
SUGI Tatsuki; YAMAGISHI Junya
The 9th Sapporo Summer Seminar for One Health, 15 Sep. 2021, English, Oral presentation

シングルセル解析によって明らかになったトキソプラズマ原虫による潜伏感染特異的宿主細胞制御
杉 達紀; 山岸 潤也
第164回日本獣医学会学術集会, 08 Sep. 2021, Japanese, Oral presentation

Amylopectin regulation in Toxoplasma gondii through phosphorylation of Glycogen Phosphorylase affects brain cyst burden
Tatsuki Sugi; YanFen Ma; Tadakimi Tomita; Rama Yakubu; Bing Han; Vincent Tu; Louis M. Weiss
Molecular Parasitology Meeting 2016, 19 Sep. 2016, English, Oral presentation
18 Sep. 2016 - 22 Sep. 2016, 29915198

病原体ゲノム解析学特論, 2024年, 博士後期課程, 国際感染症学院

Elucidation of parasitic strategy of Toxoplasma gondii in human brain using 3D neurospheroids.
Grants-in-Aid for Scientific Research
01 Apr. 2024 - 31 Mar. 2028
伴戸 寛徳; 村越 ふみ; 杉 達紀
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Asahikawa Medical College, 24K02492

Is the epigenome a major factor in evolution and adaptation? Validation using human erythrocyte-adapted Babesia parasites
Grants-in-Aid for Scientific Research
01 Apr. 2024 - 31 Mar. 2028
山岸 潤也; 麻田 正仁; 林田 京子; 杉 達紀
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 24K02270

Elucidatting molecular mechanisms by which latently infected Toxoplasma gondii evades host immunity
Grants-in-Aid for Scientific Research
01 Apr. 2022 - 31 Mar. 2025
杉 達紀
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 22K05979

トキソプラズマ原虫の急性感染および潜伏感染における宿主細胞制御の解明
科学研究費助成事業 特別研究員奨励費
25 Apr. 2014 - 31 Mar. 2017
杉 達紀
トキソプラズマ原虫は宿主との境界である寄生胞膜を、潜伏感染期特異的にさらに嚢虫壁（シスト壁）と呼ばれる構造体で裏打ちして宿主と隔てられる。
本年度の研究では潜伏感染時に宿主との相互作用を変化させる要因として原虫の形成するシスト壁に注目し、この形成を調節する原虫因子の同定および制御機序の解析を行った。
cAMPシグナルがシスト壁形成において両方向の制御を担っていることが既報で示唆されており、本研究ではProtein Kinase A (PKA)ファミリーのうち、Toxoplasma gondii PKA catalytic subunit 3 (TgPKAc３)がシスト壁形成の抑制方向のシグナルを制御していることを明らかにした。
TgPKAc3がどのようにシスト壁形成を制御しているかを明らかにするために、免疫沈降法にて相互作用因子の同定を行った。ヒットしたタンパク質の中で、典型的なPKA基質配列を持った遺伝子を絞り込んだところ、Glycogen Phosphorylase と相同なタンパク質(TgGP1)が見つかったため、この因子の解析を進めた。
TgGP1ノックアウト原虫およびリン酸化されないTgGP1S25Aでは原虫細胞はAmylopectinを過剰に貯留し、TgGP1遺伝子が機能的であることおよびリン酸化位置が重要な役割を担っていることが明らかになった。リン酸化状態であるTgGP1S25Eでは野生型原虫細胞が Amylopectinを貯留する潜伏感染期においてもAmylopectin貯留が非常に少ないことがわかった。
潜伏感染に至った原虫は厚いシスト壁を形成してしまい、宿主からのエネルギー獲得に不利益が生じると考えられる。TgPKAc3によるTgGP1の制御はシスト壁の生成とアミロペクチンとしてのエネルギー貯蔵が調和を持って制御されている仕組みの一つであると示唆された。
日本学術振興会, 特別研究員奨励費, 帯広畜産大学, 14J07030

トキソプラズマ原虫の潜伏感染を制御する原虫プロテインキナーゼの機能解析
科学研究費助成事業 特別研究員奨励費
2011 - 2013
杉 達紀
TgMAPK1がトキソプラズマの生態に果たす役割を解析するために、TgMAPK1の染色体位置上に変異を導入した。
発現誘導が可能である、Destabilizing Domain (DD)タグをタンパク質N-末に融合した形で発現するように組換に成功した。DDタグが付加されたTgMAPK1はDDタグの低分子リガンドであるshield-1存在下において、濃度依存的にタンパク質の蓄積量の増加した。Shield-1の処理により強発現となったDDタグ融合TgMAPK1は原虫の生育を止めたことから、DD-TgMAPK1がDDタグの存在により機能を損なっていることが示唆された。
HAタグをN末に付加したTgMAPK1に種々の変異を導入した配列により、原虫が持つTgMAPK1位置でノックインした原虫を作成した。低分子化合物であるBKIの一つである1NM-PP1による感受性が変化する感受性決定アミノ酸位置が、G, A, T, F, Yのそれぞれのアミノ酸に置換された変異体を作出した。Alanineを感受性決定アミノ酸に持つTgMAPK1をコードする組換原虫RH/TgMAPK1Aは、1NM-PP1により低濃度(100nM以下)で増殖が阻止されたのに対して、Tyr。sineを持つTgMAPK1をコードする組換原虫RH/TgMAPK1Yは耐性を獲得していた。1NM-PP1処理時において、核のDNA量の変化についてフローサイトメトリーで観察した。その結果RH/TgMAPK1AとRH/TgMAPK1Yともにゲノム複製の完了を示す細胞内DNA量2Nまでは相違なく進んだが、RH/TgMAPK1A (1NM-PP1感受性株)においては核分裂および細胞分裂期の進行を示す1NのDNA量を持った細胞が減少した。これは、TgMAPK1がDNA合成以降の細胞周期の中でチェックポイントとして働いていることを示唆している。
日本学術振興会, 特別研究員奨励費, 東京大学, 11J02037

ブロッキングプライマー及びその利用
Patent right, 山岸 潤也; 杉 達紀; 林田 京子, 国立大学法人北海道大学
特願2025-005095, 14 Jan. 2025

抗原虫作用を持つ生薬由来化合物と生薬エキス
Patent right, 加藤 健太郎; 村田 優穂; 杉 達紀; 野中 基弘, 国立大学法人帯広畜産大学
特願2017-083202, 19 Apr. 2017
特開2018-177733, 15 Nov. 2018
201803001086868808

抗トキソプラズマ剤
Patent right, 加藤 健太郎; 村田 優穂; 杉 達紀, 国立大学法人帯広畜産大学
特願2016-167695, 30 Aug. 2016
特開2018-035079, 08 Mar. 2018
201803018965217454

抗トキソプラズマ剤
Patent right, 加藤 健太郎; 村田 優穂; 杉 達紀, 国立大学法人帯広畜産大学
特願2016-166525, 29 Aug. 2016
特開2018-035071, 08 Mar. 2018
201803011151619255

抗原虫薬のスクリーニング方法及び組換えトキソプラズマ株
Patent right, 加藤 健太郎; 杉 達紀; 正谷 達謄, 国立大学法人帯広畜産大学, 国立大学法人 鹿児島大学
特願2014-109262, 27 May 2014
特開2015-223105, 14 Dec. 2015
201503012266540290

原虫プロテインキナーゼの即時的機能抑制が可能なトキソプラズマ原虫株
Patent right, 加藤 健太郎; 明石 博臣; 杉 達紀, 加藤 健太郎
特願2009-286975, 17 Dec. 2009
特開2011-125270, 30 Jun. 2011
201103009699557766