YOKOTA Shinichi

写真a

Affiliation

School of Medicine, Department of Microbiology

Job title

Professor
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Education 【 display / non-display 】

  • 1985
    -
    1987

    北海道大学大学院   理学研究科   化学専攻  

  • 1981
    -
    1985

    Hokkaido University   Faculty of Science   Department of Chemistry  

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Degree 【 display / non-display 】

  • Hokkaido University   M.Sc

  • The University of Tokyo   Ph.D. (Pharmaceutical Science)

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Research Experience 【 display / non-display 】

  • 2013.09
    -
    Now

    Sapporo Medical University   School of Medicine, Dept.of Microbiology   教授

    教授

  • 2007.04
    -
    2013.08

    Sapporo Medical University   School of Medicine, Dept.of Microbiology   准教授

    准教授

  • 2004.02
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    2007.03

    Sapporo Medical University   School of Medicine, Dept.of Microbiology   助教授

    助教授

  • 2000.05
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    2004.01

    Sapporo Medical University   School of Medicine, Dept.of Microbiology   講師

    講師

  • 1997.10
    -
    2000.04

    株式会社エイチ・エス・ピー研究所   副主任研究員

    副主任研究員

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Professional Memberships 【 display / non-display 】

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    Japan Endotoxin Society

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    Cell Stress Society International

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    日本ヘリコバクター学会

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    日本細菌学会

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    Japan Society for Cell Biology

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Research Areas 【 display / non-display 】

  • Life sciences   Immunology  

  • Life sciences   Virology  

  • Life sciences   Bacteriology  

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Affiliation 【 display / non-display 】

  • Sapporo Medical University   School of Medicine, Dept.of Microbiology   Professor  

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Papers 【 display / non-display 】

  • Response to pneumococcal vaccine in interstitial lung disease patients: Influence of systemic immunosuppressive treatment.

    Koji Kuronuma, Hiroyuki Honda, Tessei Mikami, Atsushi Saito, Kimiyuki Ikeda, Mitsuo Otsuka, Hirofumi Chiba, Gen Yamada, Toyotaka Sato, Shin-Ichi Yokota, Hiroki Takahashi

    Vaccine   36 ( 33 ) 4968 - 4972  2018.08  [Refereed]  [International journal]

    　View Summary

    BACKGROUND: Interstitial lung diseases (ILD) are severe respiratory diseases, and ILD patients are treated with corticosteroid and immunosuppressive agents. However, it is unclear whether these medications influence the response of pneumococcal vaccine. OBJECTIVES: We examined the immunogenicity of pneumococcal vaccines (PPSV23 and PCV13) in ILD patients undergoing immunosuppressive treatment. METHODS: ILD patients who were regularly followed at the outpatient clinic were enrolled. Sera were collected before and 4-8 weeks after vaccination. Serotype-specific immunoglobulin G (IgG) concentrations against pneumococcal serotype 19F were measured by ELISA. RESULTS: IgG concentrations to serotype 19F were increased in all groups in response to the vaccine. Both PCV13 and PPSV23 induced IgG concentrations in patients immunized for the first time. Response rates for the ILD group were comparable with those for the ILD group undergoing corticosteroid therapy. Only idiopathic pulmonary fibrosis patients undergoing immunosuppressive therapy had a significantly lower response.

    DOI PubMed

  • Isolation of a mcr-1-harbouring Escherichia coli isolate from a human clinical setting in Sapporo, Japan.

    Toyotaka Sato, Akira Fukuda, Masaru Usui, Masaaki Shinagawa, Tsukasa Shiraishi, Yutaka Tamura, Satoshi Takahashi, Shin-Ichi Yokota

    Journal of global antimicrobial resistance   13   20 - 21  2018.06  [Refereed]  [International journal]

    DOI PubMed

  • Release of large amounts of lipopolysaccharides from Pseudomonas aeruginosa cells reduces their susceptibility to colistin.

    Shin-Ichi Yokota, Hiroshi Hakamada, Soh Yamamoto, Toyotaka Sato, Tsukasa Shiraishi, Masaaki Shinagawa, Satoshi Takahashi

    International journal of antimicrobial agents   51 ( 6 ) 888 - 896  2018.06  [Refereed]  [International journal]

    　View Summary

    Pseudomonas aeruginosa is an important etiological agent of opportunistic infections. Injectable colistin is available as a last-line treatment option for multidrug-resistant P. aeruginosa infections. When cells were inoculated at a high number, colistin-susceptible P. aeruginosa grew on agar medium containing colistin at a concentration 10-fold higher than the minimum inhibitory concentration without acquiring colistin resistance. This study examined the responsible mechanism for growth in the presence of a high concentration of colistin. Cell wash fluid derived from P. aeruginosa efficiently reduced colistin antimicrobial activity. This reduction was mediated by lipopolysaccharide (LPS) in the wash fluid. Extracellular LPS inhibited colistin activity more effectively than cell-bound LPS in fixed cells. Cell wash fluids from Escherichia coli and Acinetobacter baumannii also reduced colistin activity; however, they were less potent than those from P. aeruginosa. The amount of LPS in cell wash fluid from P. aeruginosa was approximately 10-fold higher than that in fluid from E. coli or A. baumannii. In conclusion, cell-free LPS derived from bacterial cells inhibited the antimicrobial activity of colistin, and this effect was greatest for P. aeruginosa. Thus, large amounts of broken and dead cells of P. aeruginosa at infection foci will reduce the effectiveness of colistin, even against cells that have not yet acquired resistance.

    DOI PubMed

  • Evaluation of consistency in quantification of gene copy number by real-time reverse transcription quantitative polymerase chain reaction and virus titer by plaque-forming assay for human respiratory syncytial virus.

    Keisuke Yamamoto, Noriko Ogasawara, Soh Yamamoto, Kenichi Takano, Tsukasa Shiraishi, Toyotaka Sato, Hiroyuki Tsutsumi, Tetsuo Himi, Shin-Ichi Yokota

    Microbiology and immunology   62 ( 2 ) 90 - 98  2018.02  [Refereed]  [International journal]

    　View Summary

    The plaque-forming assay is the standard technique for determining viral titer, and a critical measurement for investigating viral replication. However, this assay is highly dependent on experimental technique and conditions. In the case of human respiratory syncytial virus (RSV) in particular, it can be difficult to objectively confirm the accuracy of plaque-forming assay because the plaques made by RSV are often small and unclear. In recent studies, RT-qPCR methods have emerged as a supportive procedure for assessment of viral titer, yielding highly sensitive and reproducible results. In this report, we compare the viral replication, as determined by plaque-forming assay, and the copy numbers of RSV genes NS1, NS2, N, and F, as determined by RT-qPCR. Two real-time PCR systems, SYBR Green and TaqMan probe, gave highly similar results for measurement of copy numbers of RSV N genes of virus subgroups A. We determined the RSV gene copy numbers in the culture cell supernatant and cell lysate measured at various multiplicities of infection. We found that copy number of the RSV N gene in the culture supernatant and cell lysate was highly correlated with plaque-forming units. In conclusion, RT-qPCR measurement of RSV gene copy number was highly dependent on viral titer, and the detailed comparison between each gene copy number and virus titer should be useful and supportive in confirming RSV plaque-forming assay and virus dynamics. The technique may also be used to estimate the amount of RSV present in clinical specimens.

    DOI PubMed

  • High prevalence of mcr-1, mcr-3 and mcr-5 in Escherichia coli derived from diseased pigs in Japan.

    Akira Fukuda, Toyotaka Sato, Masaaki Shinagawa, Satoshi Takahashi, Tetsuo Asai, Shin-Ichi Yokota, Masaru Usui, Yutaka Tamura

    International journal of antimicrobial agents   51 ( 1 ) 163 - 164  2018.01  [Refereed]  [International journal]

    DOI PubMed

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Books and Other Publications 【 display / non-display 】

  • シンプル微生物学（改訂第6版）

    横田伸一( Part： Joint author, らせん菌群)

    南江堂  2018

  • 標準微生物学（第12版）

    横田伸一( Part： Joint author, エンドトキシン（リポ多糖）)

    医学書院  2018

  • 病原微生物学―基礎と臨床

    横田伸一( Part： Joint author, グラム陰性好気性桿菌)

    東京化学同人  2014

  • みてわかる薬学 図解 微生物学・感染症・化学療法

    横田伸一( Part： Joint author, 感染症と生体防御，化学療法（抗菌薬）)

    南山堂  2014

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Misc 【 display / non-display 】

  • 抗菌薬多剤耐性におけるefflux pumpの役割を見直す

    横田伸一, 佐藤豊孝

    化学療法の領域 ( (株)医薬ジャーナル社 )  33 ( 8 ) 1698 - 1703  2017  [Invited]

    Article, review, commentary, editorial, etc. (scientific journal)  

    　View Summary

    抗菌薬耐性菌の拡大はAMR(antimicrobial resistance)問題として国際的に早急なアクションが求められている。私たちは,現時点で感受性率の高い薬剤や多剤耐性菌感染症治療の最終選択肢として位置づけられている薬剤の耐性機序に特に着目している。耐性率の低いうちに耐性機序を詳細に検討することが今後の耐性拡大阻止につながると考える。本稿では,大腸菌臨床分離株を用いた私たちの最近の研究から,フルオロキノロン耐性,チゲサイクリン耐性,タゾバクタム/ピペラシリン耐性について述べる。これらには,薬剤排出ポンプ(efflux pump)による菌体からの薬剤の排出が共通して関与していた。Efflux pumpは多剤耐性をもたらす機構として位置づけられているが,それ単独では必ずしも高度な耐性の付与までには至らないと認識されてきた。私たちはefflux pumpがもたらす抗菌薬耐性の重要性を再認識するに至った。(著者抄録)

  • 納豆由来ペプチドの特異な殺菌効果とその作用機序

    白石宗, 北川学, 山本聡, 久富亮佑, 佐藤豊孝, 涌井秀樹, 伊藤英晃, 宮本篤, 横田伸一

    エンドトキシン・自然免疫研究20－自然免疫における化学生物学の貢献－ ( 日本エンドトキシン・自然免疫研究会 )  20   39 - 42  2017

    Article, review, commentary, editorial, etc. (other)  

  • Characteristics of lactic acid bacteria from the view of the structural diversity of lipoteichoic acids

    白石宗, 横田伸一, 吹谷智, 横田篤

    JATAFFジャーナル ( 農林水産・食品産業技術振興協会 )  5 ( 3 ) 26 - 32  2017

    Article, review, commentary, editorial, etc. (scientific journal)  

    CiNii

  • 抗菌薬耐性菌の驚くべき進化と脅威

    横田伸一

    日本耳鼻咽喉科感染症・エアロゾル学会会誌   4 ( 1 ) 7 - 13  2016  [Invited]

    Article, review, commentary, editorial, etc. (scientific journal)  

  • Lactobacillus gasseri JCM 1131Tの対数期におけるリポテイコ酸の局在：Membrane vesicle表層に露出されるリポテイコ酸

    白石宗, 佐藤耶舞羽, 横田伸一, 伊藤利章, 吹谷智, 横田篤

    エンドトキシン・自然免疫研究19－新たなる基礎と臨床の架け橋－   19   15 - 17  2016

    Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

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Awards 【 display / non-display 】

  • 奨励研究賞

    2017   マクロライド新作用研究会  

    Winner： 横田 伸一

  • 第6回小林六造記念ヘリコバクター賞

    2010   日本ヘリコバクター学会  

    Winner： 横田 伸一

  • 黒住医学研究振興財団研究助成

    2008  

    Winner： 横田 伸一

  • 金原一郎記念医学医療振興財団研究助成

    2005  

  • The Ichiro Kanehara Foundation

    2005  

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Research Projects 【 display / non-display 】

  • ピロリ菌の発癌に関わる病原因子としてのリポ多糖の多様性

    Project Year :

    2012
    -
    2014
     

    横田伸一

    Authorship： Principal investigator

  • 低毒性であるピロリ菌リポ多糖の炎症反応惹起機構

    Project Year :

    2008
    -
    2010
     

    横田伸一

    Authorship： Principal investigator

  • ウイルスの宿主免疫抑制機構の解除に着目した抗ウイルス薬創製の基盤的研究

    Project Year :

    2006
    -
    2007
     

    横田伸一

    Authorship： Principal investigator

  • ヘルペスウイルスの増殖にかかわる宿主細胞情報伝達系の修飾

    Project Year :

    2002
    -
    2004
     

    横田伸一

    Authorship： Principal investigator

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