Emerging process of Enterohemorrhagic Escherichia coli revealed by a large-scale genome analysis

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H04077
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Bacteriology (including mycology)
• Research Institution: Kyushu University
• Principal Investigator: Yoshitoshi Ogura 九州大学, 医学研究院, 准教授 (40363585)
• Co-Investigator(Kenkyū-buntansha): 梶谷 嶺 東京工業大学, 生命理工学院, 助教 (40756706)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 志賀毒素産生性大腸菌 / 腸管病原性大腸菌 / 志賀毒素 / ３型分泌装置 / 進化 / ゲノム

Outline of Final Research Achievements

To develop infection control strategies, better understanding of the evolutionary processes of pathogens is essential. Shiga toxin (Stx)-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) are important human pathogens sharing cattle as the primary reservoir. Here, a large-scale genomic comparison of bovine and human commensal E. coli and clinical STEC and EPEC strains reveals that bovine commensal strains are phylogenetically distinct from human commensal strains and that the bovine-adapted lineage is serving as evolutionary sources of the emergence of STEC and EPEC. Identification of virulence gene communities each accumulated in STEC and EPEC suggests the presence of a selection pressure(s) to promote their accumulation in bovine intestine, which could be targets for developing efficient strategies to control these pathogens.

Free Research Field

細菌学、ゲノム科学

Academic Significance and Societal Importance of the Research Achievements

本研究により、ウシ腸内には、ウシ常在大腸菌へ多数の病原因子を蓄積させる選択圧が存在する可能性が示された。その選択圧の候補の１つとして、ウシ腸内で大腸菌を捕食している原生生物が挙げられる。今後は、その選択圧を明らかにし、病原性大腸菌出現の仕組みを完全に解明することで、病原性大腸菌を制御する手法の開発が可能となり、病原性大腸菌感染症の予防や安全な食肉生産に繋がると期待される。