Research on factors regulating sporulation and enterotoxin production in Clostridium perfringens causing food-borne illness

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K08783
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Hygiene and public health
• Research Institution: Osaka Prefecture University
• Principal Investigator: YASUGI Mayo 大阪府立大学, 生命環境科学研究科, 准教授 (40589008)
• Research Collaborator: NAKAMURA shota ; NARIYA hirofumi
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: ウェルシュ菌 / 食中毒 / 芽胞形成 / 毒素産生 / 胆汁酸 / レドックス / Spo0A

Outline of Final Research Achievements

Sporulation in Clostridium perfringens causing food-borne illness is a key event for its pathogenesis because sporulation and production of enterotoxin are co-regulated under the signal cascade for sporulation. We found that bile salts induced sporulation by accelerating phosphorylation of Spo0A, master regulator of sporulation. To identify bacterial factor(s) for phosphorylation, we have established transposon based random mutagenesis and analyzed using next generation sequencer. We found 39 candidate genes that are possible to induce phosphorylation of Spo0A. We also found that an oxidant, nitrate inhibited sporulation by regulating Spo0A activation step (dimerization of Spo0A or binding to promoters of Spo0A-regulated genes).

Free Research Field

感染症学

Academic Significance and Societal Importance of the Research Achievements

ウェルシュ菌食中毒では芽胞形成が病気発症の主要イベントであり、その分子機序の解明を通した病気発症の制御法の開発が期待される。本研究の学術的意義は、芽胞形成に関与する因子とその作用機序の一部を明らかにすることで、病気発症機序の理解に新たな視点を与えた点、ならびに宿主体内における病原微生物の生存戦略の一端の解明に繋がる基盤知見を創出した点にある。
また、作用機序の解明は芽胞形成の制御を通した食中毒の予防法の開発へと研究の応用が期待されるが、本研究はその基盤知見の創出に貢献した点に社会的意義がある。