Researcher Number(JSPS Kakenhi)


Laboratory Address

207 Uehara,Nishihara,Okinawa

Mail Address

E-mail address

Current Affiliation Organization 【 display / non-display

  • Duty   University of the Ryukyus   Graduate School of Medicine   Professor  

University 【 display / non-display


    University of the Ryukyus   Faculty of Medicine   Graduated

Graduate School 【 display / non-display


    University of the Ryukyus  Graduate School, Division of Medicine  Doctor's Course  Completed

External Career 【 display / non-display

  • 2016.04

    University of the Ryukyus, Graduate School of Medicine, Professor  

  • 2005.12

    Institute of Tropical Medicine, Nagasaki University  

  • 2000.08

    Department of Microbiology, Faculty of Medicine, Oita University  

  • 1994.04


Research Areas 【 display / non-display

  • Life Science / Bacteriology

Acquisition of a qualification 【 display / non-display

  • Doctor

Research Theme 【 display / non-display

  • Pathogenesis of Vibrio cholerae

Published Papers 【 display / non-display

  • Fermentation products of the fungus Monascus spp. impairs the physiological activities of toxin-producing Vibrio cholerae

    Jun Xu, Rino Arakaki, Shinjiro Tachibana, Tetsu Yamashiro

    Microbiological Research ( Elsevier BV )  258   126995   2022.05 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

     View Summary

    Monascus spp. are filamentous fungi used in fermented foods. They are also natural colorants and food preservatives. Certain metabolites of Monascus spp. lower cholesterol and have other health-promoting effects in humans. In the present study, we demonstrated that the fermentation products of Monascus spp. inhibited ATP synthesis and motility in toxigenic Vibrio cholerae. Single-cell tracking and rotation assays on single flagella showed that Monascus fermentation extract (MFE) significantly impaired V. cholerae swimming by disrupting flagellar rotation. A membrane potential-sensitive carbocyanine dye revealed that MFE depolarized the V. cholerae cell membrane which, in turn, lowered the membrane potential and, by extension, restricted ATP synthesis and flagellar rotation. MFE also severely hindered the motility of other pathogenic bacteria such as V. parahaemolyticus, Pseudomonas aeruginosa, Salmonella enterica Typhimurium, and Leptospira interrogans. The foregoing findings indicate that Monascus fermentation extract could potentially preventing infection caused by multiple pathogenic bacteria as the conventional prophylaxes and slow their progression and lower mortality and morbidity.

  • Analysis of human clinical and environmental Leptospira to elucidate the eco-epidemiology of leptospirosis in Yaeyama, subtropical Japan

    Yukuto Sato , Idam Hermawan , Tetsuya Kakita , Sho Okano , Hideyuki Imai , Hiroto Nagai , Ryosuke Kimura , Tetsu Yamashiro , Tadashi Kajita , Claudia Toma

    PLOS Neglected Tropical Diseases ( Public Library of Science (PLoS) )    2022.03 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

  • Risk Factors Associated with Diarrheal Episodes in an Agricultural Community in Nam Dinh Province, Vietnam: A Prospective Cohort Study.

    Hanako Iwashita , Asako Tokizawa , Vu Dinh Thiem , Taichiro Takemura , Tuan Hai Nguyen , Hang Thi Doan , Anh Hong Quynh Pham , Na Ly Tran , Tetsu Yamashiro

    International journal of environmental research and public health     2022.02 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

  • Disassembly of the apical junctional complex during the transmigration of Leptospira interrogans across polarized renal proximal tubule epithelial cells

    Isabel Sebastián , Nobuhiko Okura , Bruno M. Humbel , Jun Xu , Idam Hermawan , Chiaki Matsuura , Malgorzata Hall , Chitoshi Takayama , Tetsu Yamashiro , Shuichi Nakamura , Claudia Toma

    Cellular Microbiology     2021.05 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

  • Immunological Responses to Seoul Orthohantavirus in Experimentally and Naturally Infected Brown Rats (Rattus norvegicus)

    Shumpei P. Yasuda , Kenta Shimizu , Takaaki Koma , Nguyen Thuy Hoa , Mai Quynh Le , Zhuoxing Wei , Devinda S. Muthusinghe , Sithumini M. W. Lokupathirage , Futoshi Hasebe , Tetsu Yamashiro , Jiro Arikawa , Kumiko Yoshimatsu

    Viruses     2021.04 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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