Prevalence, antimicrobial susceptibility and characterization of typical and atypical EPEC in Thailand and Kenya

• Project/Area Number: 17H04651
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Bacteriology (including mycology)
• Research Institution: Osaka Prefecture University
• Principal Investigator: Yamasaki Shinji 大阪府立大学, 生命環境科学研究科, 教授 (70221653)
• Co-Investigator(Kenkyū-buntansha): 日根野谷 淳 大阪府立大学, 生命環境科学研究科, 准教授 (20548490) ; 飯島 義雄 神戸市環境保健研究所, その他部局等, 所長 (60144739)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥15,600,000 (Direct Cost: ¥12,000,000、Indirect Cost: ¥3,600,000); Fiscal Year 2019: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2018: ¥5,850,000 (Direct Cost: ¥4,500,000、Indirect Cost: ¥1,350,000); Fiscal Year 2017: ¥5,460,000 (Direct Cost: ¥4,200,000、Indirect Cost: ¥1,260,000)
• Keywords: eae遺伝子 / 下痢原性大腸菌 / aEPEC / tEPEC / E. albertii / 感染症 / 細菌 / 獣医学

Outline of Final Research Achievements

food samples, in particular, meats in both Thailand and Kenya. However, bundle forming pilus (bfp) gene was not detected in the same sample and even in eae gene-positive Escherichia coli isolated. These data indicate that atypical enteropathogenic E. coli (only eae gene-positive) is prevalent but not typical enteropathogenic E. coli (both eae and bfp gene-positive) in Thailand and Kenya. In addition, Escherichia albertii specific gene such as Eacdt genes were also detected in meat samples as well as stool specimens of diarrheal patients in Thailand. Furthermore, E. albertii was isolated from not only meat samples but also diarrheal patient. The isolates do not contain stx2 genes but produce biological active cytolethal distending toxin. Two E. albertii isolates were multi-drug resistant. Taken together, eae gene-positive bacteria such as aEPEC and E. albertii might be important emerging zoonotic pathogens.

Academic Significance and Societal Importance of the Research Achievements

eae、bfp及びEAF遺伝子が陽性のEPECが、特に開発途上国では下痢症の原因であると考えられてきた。今回、タイ、ケニアにおいてeae遺伝子のみ陽性のaEPECが主流であることが明らかとなった。aEPECはstx2ファージが感染することでEHEC になることからtEPECよりより病原性が強いと言われている。一方、今回初めてE. albertiiをタイの食品のみならず下痢症患者便から検出した。今後、aEPECとtEPECを鑑別できる検査法やE. albertiiの検査法を普及することで、これらの細菌の疫学や下痢症起因菌としての位置づけをより明確にできることが期待できる。

Research Products

• [Int'l Joint Research] Kuwait University(クウェート)
• [Int'l Joint Research] Mombasa University of Technology(ケニア)
• [Int'l Joint Research] Thammassat University(タイ)
• [Journal Article] Development of a multiplex PCR for the simultaneous detection of eae, stx and cdt genes in genus Escherichia and detection of a novel cdtB gene in Providencia rustigianii (2018)
  • Author(s): J. Hassan, S.P. Awasthi, N. Hatanaka, K. Okuno, P.H. Hoang, A. Nagita, A. Hinenoya and S. Yamasaki
  • Journal Title: Pathog. Dis. Volume: 76 Pages: 1-7
  • DOI: 10.1093/femspd/ftz002
  • Peer Reviewed
• [Journal Article] Association of cytolethal distending toxin-II gene-positive Escherichia coli with Escherichia albertii, an emerging entropathogen (2017)
  • Author(s): Hinenoya A, Yasuda N, Mukaizawa N, Sheikh S, Niwa Y, Awasthi SP, Asakura M, Tsukamoto T, Nagita A, Albert MJ, Yamasaki S
  • Journal Title: Int. J. Med. Microbiol. Volume: 307 Pages: 564-571
  • DOI: 10.1016/j.ijmm.2017.08.008
  • Peer Reviewed / Int'l Joint Research