論文 - 目堅 博久
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Yukiko Sato, Hirohisa Mekata, Putu Eka Sudaryatma, Yumi Kirino, Seigo Yamamoto, Shuji Ando, Takayuki Sugimoto, Tamaki Okabayashi
Vector-Borne and Zoonotic Diseases 21 ( 5 ) 378 - 384 2021年5月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Mary Ann Liebert Inc
Severe fever with thrombocytopenia syndrome (SFTS), caused by Dabie bandavirus, generally called SFTS virus (SFTSV), is an emerging zoonosis in East Asia. In Japan, 50-100 cases of SFTS have been reported each year since the first case was reported in 2013. SFTS is a tick-borne infectious disease, and SFTSV has been isolated from ticks in China and South Korea. Haemaphysalis longicornis and Amblyomma testudinarium are considered the primary vectors in Japan. However, the other tick species seldom feeding on humans might also play an important role in maintaining the virus in nature. In this study, we collected ticks on vegetation around the location where two SFTS patients were estimated to have been infected in Miyazaki Prefecture, Japan, isolated live SFTSV, and performed a phylogenetic analysis. A total of 257 ticks were collected, and SFTSV RNA was detected in 19.5% (9/46) of tick pools. A total of 10 infectious SFTSVs were successfully isolated from A. testudinarium, Haemaphysalis flava, Haemaphysalis formosensis, Haemaphysalis hystricis, and Haemaphysalis megaspinosa. Furthermore, the whole viral sequences isolated from ticks were highly homologous to sequences isolated from SFTS patients in the same sampling area in the past. These results suggest that SFTSVs are maintained in these tick species in the sampling area and sporadically transmitted to humans. Surveillance of SFTSV in ticks provides important information about the risk of incidental transmission to humans.
その他リンク： https://www.liebertpub.com/doi/pdf/10.1089/vbz.2020.2720
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Molecular Epidemiology and Whole-Genome Analysis of Bovine Foamy Virus in Japan 査読あり 国際誌
Hirohisa Mekata, Tomohiro Okagawa, Satoru Konnai, Takayuki Miyazawa
Viruses 13 ( 6 ) 1017 - 1017 2021年5月
担当区分：筆頭著者, 責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：MDPI AG
Bovine foamy virus (BFV) is a member of the foamy virus family in cattle. Information on the epidemiology, transmission routes, and whole-genome sequences of BFV is still limited. To understand the characteristics of BFV, this study included a molecular survey in Japan and the determination of the whole-genome sequences of 30 BFV isolates. A total of 30 (3.4%, 30/884) cattle were infected with BFV according to PCR analysis. Cattle less than 48 months old were scarcely infected with this virus, and older animals had a significantly higher rate of infection. To reveal the possibility of vertical transmission, we additionally surveyed 77 pairs of dams and 3-month-old calves in a farm already confirmed to have BFV. We confirmed that one of the calves born from a dam with BFV was infected. Phylogenetic analyses revealed that a novel genotype was spread in Japan. In conclusion, the prevalence of BFV in Japan is relatively low and three genotypes, including a novel genotype, are spread in Japan.
DOI： 10.3390/v13061017
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Yuki Fukushima, Tomoya Minamino, Yoko Mikurino, Kazuyuki Honkawa, Yoichiro Horii, Takako Taniguchi, Hirohisa Mekata, Yosuke Sasaki
Pathogens 10 ( 6 ) 650 - 650 2021年5月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：MDPI AG
The objective of the present study was to investigate the effects of Theileria orientalis on the severity of anemia, the prevalence of disease within 21 days after calving and productivity in cows raised inside barns. This longitudinal observational study, which was conducted on a commercial dairy farm in Japan, involved 627 Holstein cows subjected to PCR analysis for T. orientalis. In study 1, we collected blood samples from 156 sick cows within 21 days after calving, and we found the prevalence of T. orientalis infection to be 65.4%. In study 2, we randomly selected 471 cows during the dry period and collected blood samples to conduct PCR analysis for T. orientalis and determined the prevalence of T. orientalis infection to be 69.0%. Compared with the values for the T. orientalis-uninfected group, the T. orientalis-infected cows had significantly decreased hemoglobin concentrations and hematocrit, but there were no differences in the other complete blood count indexes between the two groups. In addition, there were no differences in productivity and the prevalence of major diseases between the T. orientalis-infected and uninfected cows. In summary, T. orientalis had few effects on anemia, productivity and the health of cows raised inside a barn.
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Bovine respiratory coronavirus enhances bacterial adherence by upregulating expression of cellular receptors on bovine respiratory epithelial cells. 査読あり 国際誌
Watcharapong Fahkrajang, Putu Eka Sudaryatma, Hirohisa Mekata, Saori Hamabe, Akatsuki Saito, Tamaki Okabayashi
Veterinary microbiology 255 109017 - 109017 2021年4月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
Bovine coronavirus (BCoV) is one of the agents causing bovine respiratory disease complex (BRDC), with single infection tending to be mild to moderate; the probability of developing pneumonia in BRDC may be affected by viral and bacterial combinations. Previously, we reported that bovine respiratory syncytial virus (BRSV) infection enhances adherence of Pasteurella multocida (PM) to cells derived from the bovine lower respiratory tract but that BRSV infection in cells derived from the upper respiratory tract reduces PM adherence. In this study, we sought to clarify whether the modulation of bacterial adherence to cells derived from the bovine upper and lower respiratory tract is shared by other BRDC-related viruses by infecting bovine epithelial cells from the trachea, bronchus and lung with BCoV and/or PM. The results showed that cells derived from both the upper and lower respiratory tract were susceptible to BCoV infection. Furthermore, all cells infected with BCoV exhibited increased PM adherence via upregulation of two major bacterial adhesion molecules, intercellular adhesion molecule-1 (ICAM-1) and platelet-activating factor receptor (PAF-R), suggesting that compared with BRSV infection, BCoV infection differentially modulates bacterial adherence. In summary, we identified distinct interaction between bovine respiratory viruses and bacterial infections.
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Chiho KANEKO, Yasuyuki KANEKO, Putu Eka SUDARYATMA, Hirohisa MEKATA, Yumi KIRINO, Ryoji YAMAGUCHI, Tamaki OKABAYASHI
Journal of Veterinary Medical Science 83 ( 4 ) 680 - 684 2021年4月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Japanese Society of Veterinary Science
We isolated two pseudorabies virus (PRV) isolates (designated OT-1 and OT-2) from two hunting dogs exhibiting neurological manifestations after eating the flesh of wild boar hunted in Oita prefecture, Kyushu Island, Japan. The isolates corresponded to a previously reported PRV (MY-1 strain) isolated from a hunting dog in neighboring Miyazaki prefecture, and it clustered into genotype II based on the glycoprotein C sequence. Our results suggest that this common PRV strain may have been maintained in wild boars on Kyushu Island even though domestic pigs in this area have attained an Aujeszky's disease-free status.
DOI： 10.1292/jvms.20-0450
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Metagenomic identification, sequencing, and genome analysis of porcine hepe-astroviruses (bastroviruses) in porcine feces in Japan. 査読あり 国際誌
Makoto Nagai, Tamaki Okabayashi, Masataka Akagami, Aya Matsuu, Yoshikazu Fujimoto, Md Abul Hashem, Hirohisa Mekata, Ryo Nakao, Keita Matsuno, Yukie Katayama, Mami Oba, Tsutomu Omatsu, Tetsuo Asai, Keisuke Nakagawa, Hiroshi Ito, Hiroo Madarame, Kazuhiro Kawai, Toshihiro Ito, Nariaki Nonaka, Kyoko Tsukiyama-Kohara, Yasuo Inoshima, Tetsuya Mizutani, Naoaki Misawa
Infection, genetics and evolution 88 104664 - 104664 2021年3月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Elsevier BV
Recently, hepe-astrovirus-like RNA viruses named bastroviruses (BastVs), have been found in human, pig, bat, and rat fecal samples. In this study, we determined nearly complete genome sequences of four BastVs in the feces of healthy pigs. Genetic characterization revealed that these porcine BastVs (PBastVs) and BastVs from other animals including humans, had the same genome organization, that is, they contained three predicted conserved domains of viral methyltransferase, RNA helicase, and RdRp in the nonstructural ORF1 and the astrovirus capsid domain in the structural ORF2. Phylogenetic analyses using RNA-dependent RNA polymerase and the capsid region revealed that PBastVs branched with bat and rat BastVs; however, the groups formed by each host were distantly related to human BastVs. Pairwise amino acid sequence comparison demonstrated that PBastVs shared 95.2-98.6% and 76.1-95.5% sequence identity among each other in the ORF1 and ORF2 regions, respectively; the sequence identities between PBastVs and BastVs from other animals were 21.4-42.5% and 9.1-20.6% in the ORF1 and ORF2 regions, respectively. This suggested that BastVs were derived from a common ancestor but evolved independently in each host population during a prolonged period. Putative recombination events were identified in the PBastV genome, suggesting that PBastVs gain sequence diversity and flexibility through recombination events. In an analysis of previously obtained metagenomic data, PBastV sequence reads were detected in 7.3% (23/315) of fecal samples from pigs indicating that PBastVs are distributed among pig populations in Japan.
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Yumi Kirino, Keita Ishijima, Miho Miura, Taro Nomachi, Eugene Mazimpaka, Putu Eka Sudaryatma, Atsushi Yamanaka, Ken Maeda, Takayuki Sugimoto, Akatsuki Saito, Hirohisa Mekata, Tamaki Okabayashi
Viruses 13 ( 2 ) 229 - 229 2021年2月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：MDPI AG
Severe fever with thrombocytopenia syndrome virus (SFTSV) is the causative agent of SFTS, an emerging tick-borne disease in East Asia, and is maintained in enzootic cycles involving ticks and a range of wild animal hosts. Direct transmission of SFTSV from cats and dogs to humans has been identified in Japan, suggesting that veterinarians and veterinary nurses involved in small-animal practice are at occupational risk of SFTSV infection. To characterize this risk, we performed a sero-epidemiological survey in small-animal-practice workers and healthy blood donors in Miyazaki prefecture, which is the prefecture with the highest per capita number of recorded cases of SFTS in Japan. Three small-animal-practice workers were identified as seropositive by ELISA, but one had a negative neutralization-test result and so was finally determined to be seronegative, giving a seropositive rate of 2.2% (2 of 90), which was significantly higher than that in healthy blood donors (0%, 0 of 1000; p < 0.05). The seroprevalence identified here in small-animal-practice workers was slightly higher than that previously reported in other high-risk workers engaged in agriculture and forestry in Japan. Thus, enhancement of small-animal-practice workers’ awareness of biosafety at animal hospitals is necessary for control of SFTSV.
DOI： 10.3390/v13020229
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Yasuko Yamazaki, Uraiwan Thongchankaew-Seo, Konomu Nagao, Hirohisa Mekata, Wataru Yamazaki
Letters in applied microbiology 71 ( 6 ) 560 - 566 2020年12月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Wiley
Along with progress in globalization of society, the spread of infectious diseases has accelerated worldwide. The deployment of highly sensitive genetic tests is essential for early diagnosis and early containment of potential outbreaks and epidemics, as well as routine surveillance, however tedious and expensive nucleic acid extraction steps represent a major drawback. Here we developed a simple and rapid DNA extraction method, named as an EZ-Fast kit, applicable to the field setting. The kit does not require advanced laboratory equipment or expensive DNA extraction kits and achieves crude DNA extraction within 10 min at extremely low cost and can easily be performed in field settings. When combined with real-time PCR and LAMP analyses, the performance of the POCT, using 183 bovine blood samples, was similar to that of the existing DNA extraction method: 92.5% (135/146) (real-time PCR) and 93.7% (133/142) (LAMP) diagnostic sensitivities, and 100% diagnostic specificities. The developed POCT provides a powerful tool to facilitate on-site diagnosis in a field setting.
DOI： 10.1111/lam.13376
その他リンク： https://onlinelibrary.wiley.com/doi/full-xml/10.1111/lam.13376
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Direct Transmission of Severe Fever with Thrombocytopenia Syndrome Virus from Domestic Cat to Veterinary Personnel. 査読あり 国際誌
Atsushi Yamanaka, Yumi Kirino, Sho Fujimoto, Naoyasu Ueda, Daisuke Himeji, Miho Miura, Putu E Sudaryatma, Yukiko Sato, Hidenori Tanaka, Hirohisa Mekata, Tamaki Okabayashi
Emerging infectious diseases 26 ( 12 ) 2994 - 2998 2020年12月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Centers for Disease Control and Prevention (CDC)
Two veterinary personnel in Japan were infected with severe fever with thrombocytopenia syndrome virus (SFTSV) while handling a sick cat. Whole-genome sequences of SFTSV isolated from the personnel and the cat were 100% identical. These results identified a nosocomial outbreak of SFTSV infection in an animal hospital without a tick as a vector.
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Putu Eka Sudaryatma, Akatsuki Saito, Hirohisa Mekata, Meiko Kubo, Watcharapong Fahkrajang, Eugene Mazimpaka, Tamaki Okabayashi
Frontiers in microbiology 11 1676 - 1676 2020年7月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Frontiers Media SA
Coinfection by bovine respiratory syncytial virus (BRSV) and Pasteurella multocida (PM) frequently has been observed in cattle that develop severe pneumonia. We recently reported that BRSV infection significantly increased PM adherence to bovine lower respiratory tract epithelial cells. However, the molecular mechanisms of enhanced PM adherence are not completely understood. To investigate whether BRSV infection regulates any cellular adherence receptors on bovine bronchus- and lung-epithelial cells, we performed proteomic and functional analyses. The proteomic analysis showed that BRSV infection increased the accumulation of the platelet-activating factor receptor (PAFR) in both cell types. Molecular experiments, including specific blockade, knockdown, and overexpression of PAFR, indicated that PM adherence to these cell types depended on PAFR expression. These findings highlight the role, in cattle with severe pneumonia, of the synergistic effect of coinfection by BRSV and PM in the lower respiratory tract.
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Bovine Respiratory Syncytial Virus Decreased Pasteurella multocida Adherence by Downregulating the Expression of Intercellular Adhesion Molecule-1 on the Surface of Upper Respiratory Epithelial Cells. 査読あり 国際誌
Putu Eka Sudaryatma, Akatsuki Saito, Hirohisa Mekata, Meiko Kubo, Watcharapong Fahkrajang, Tamaki Okabayashi
Veterinary microbiology 246 108748 - 108748 2020年7月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Elsevier BV
The synergistic infection of bovine respiratory syncytial virus (BRSV) and Pasteurella multocida (PM) may predispose cattle to develop severe pneumonia. Previously, we reported that BRSV infection significantly decreased PM adherence to the upper respiratory epithelial cells. It may allow bacteria to invade into the lower respiratory tract and lead to severe pneumonia. To investigate whether BRSV infection regulates the cell surface adherence receptor on bovine trachea epithelial cells (bTECs), we performed proteomic and functional analyses. BRSV infection decreased the expression of intercellular adhesion molecule-1 (ICAM1) on bTECs. Inhibition and knockdown experiments using anti-ICAM1 antibody and siRNAs targeting ICAM1 indicated that PM adherence to bTECs was dependent on ICAM1 expression. These data suggest that under normal conditions bTECs may capture PM in the upper respiratory tract, while BRSV infection reverses this mechanism. The proposed gateway function of bTECs is disrupted by BRSV infection that may facilitate bacterial invasion into the lower respiratory tract and lead to secondary or more severe respiratory infection.
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Ryohei Makino, Yasuko Yamazaki, Konomu Nagao, Francis Victor Apego, Hirohisa Mekata, Wataru Yamazaki
Food and environmental virology 12 ( 2 ) 167 - 173 2020年6月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Springer Science and Business Media LLC
Highly sensitive detection of pathogens is effective for screening meat during quarantine inspection and export. The "micro-amount of virion enrichment technique" (MiVET) was recently developed, which is a new method combining virus concentration with immunomagnetic beads and simple RNA extraction with sodium dodecyl benzenesulfonate (SDBS) for the specific and sensitive detection of avian influenza viruses (AIVs). AIV subtypes H3N2 and H4N2 were used to spike the surface of chicken breast meat samples. The modified MiVET protocol was tested by comparing it against three different homogenate preparation conditions, as well as in samples with added α-amylase and collagenase to digest inhibitors. The performance of the modified MiVET was evaluated by real-time RT-PCR assay targeting the matrix gene. Compared with conventional RNA extraction, the modified MiVET reproducibly concentrated AIVs in chicken meat samples with 100-1000-fold improvement by 60 s-hand homogenization. The 30 s- and 60 s-stomacher homogenizations resulted 100-fold and 10-100-fold improvement, respectively. The modified MiVET required < 60 min from homogenate preparation to final RNA elution. Further, use of the modified MiVET also decreased the rate of false-negative results. The modified MiVET is effective for the rapid and highly sensitive detection of AIVs in chicken meat samples, and can be applied to quarantine and export inspection at airports and seaports.
DOI： 10.1007/s12560-020-09425-1
その他リンク： http://link.springer.com/article/10.1007/s12560-020-09425-1/fulltext.html
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Hirohisa Mekata, Saori Hamabe, Putu Eka Sudaryatma, Ikuo Kobayashi, Toru Kanno, Tamaki Okabayashi
Journal of Veterinary Medical Science 82 ( 6 ) 726 - 730 2020年6月
担当区分：筆頭著者, 責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Japanese Society of Veterinary Science
Bovine coronavirus (BCoV) is an etiological agent of bovine respiratory disease (BRD). BRD is a costly illness worldwide; thus, epidemiological surveys of BCoV are important. Here, we conducted a molecular epidemiological survey of BCoV in respiratory-diseased and healthy cattle in Japan from 2016 to 2018. We found that 21.2% (58/273) of the respiratory-diseased cattle were infected with BCoV. The respiratory-diseased cattle had virus amounts 4.7 times higher than those in the asymptomatic cattle. Phylogenetic analyses showed that the BCoV identified in Japan after 2005 formed an individual lineage that was distinct from the strains found in other countries. These results suggest that BCoV is epidemic and has evolved uniquely in Japan.
DOI： 10.1292/jvms.19-0587
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Slaughterhouse survey for detection of bovine viral diarrhea infection among beef cattle in Kyushu, Japan. 査読あり 国際誌
Agah MA, Notsu K, El-Khaiat HM, Arikawa G, Kubo M, Mitoma S, Okabayashi T, Mekata H, Elhanafy E, El Daous H, Mai TN, Nguyen TH, Isoda N, Sakoda Y, Norimine J, Sekiguchi S
Journal of Veterinary Medical Science 81 ( 10 ) 1450 - 1454 2019年10月
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Co-infection of epithelial cells established from the upper and lower bovine respiratory tract with bovine respiratory syncytial virus and bacteria. 査読あり 国際誌
Sudaryatma PE, Mekata H, Kubo M, Subangkit M, Goto Y, Okabayashi T
Veterinary microbiology 235 80 - 85 2019年8月
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Development of a fluorescent loop-mediated isothermal amplification assay for rapid and simple diagnosis of bovine leukemia virus infection. 査読あり 国際誌
Nagao K, Makino R, Apego FV, Mekata H, Yamazaki W
Journal of Veterinary Medical Science 81 ( 5 ) 787 - 792 2019年5月
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Evaluation of the natural vertical transmission of Theileria orientalis. 査読あり 国際誌
Mekata H, Minamino T, Mikurino Y, Yamamoto M, Yoshida A, Nonaka N, Horii Y
Veterinary parasitology 263 1 - 4 2018年11月
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New Micro-amount of Virion Enrichment Technique (MiVET) to Detect Influenza A Virus in the Duck Feces. 査読あり 国際誌
Yamazaki W, Makino R, Nagao K, Mekata H, Tsukamoto K
Transboundary and emerging diseases 66 ( 1 ) 341 - 348 2018年9月
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Cattle with a low bovine leukemia virus proviral load are rarely an infectious source 査読あり 国際誌
Mekata H, Yamamoto M, Hayashi T, Kirino Y, Sekiguchi S, Konnai S, Horii Y, Norimine J
Japanese Journal of Veterinary Research 66 ( 3 ) 157 - 163 2018年8月
記述言語：英語 掲載種別：研究論文（学術雑誌）
その他リンク： https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/71336/1/p157-163%20Hirohisa_Mekata.pdf
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Bovine respiratory syncytial virus infection enhances Pasteurella multocida adherence on respiratory epithelial cells. 査読あり 国際誌
Sudaryatma PE, Nakamura K, Mekata H, Sekiguchi S, Kubo M, Kobayashi I, Subangkit M, Goto Y, Okabayashi T
Veterinary microbiology 220 33 - 38 2018年7月