Escherichia coli O8:H8 Carrying a Novel Variant of the Heat-Labile Enterotoxin LT2 Gene Caused Outbreaks of Diarrhea

Kai Ishimaru; Mari Sasaki; Hiroshi Narimatsu; Yoko Arimizu; Yasuhiro Gotoh; Keiji Nakamura; Tetsuya Hayashi; Yoshitoshi Ogura

doi:10.1093/ofid/ofaa021

Escherichia coli O8:H8 Carrying a Novel Variant of the Heat-Labile Enterotoxin LT2 Gene Caused Outbreaks of Diarrhea

Open Forum Infect Dis. 2020 Jan 14;7(1):ofaa021. doi: 10.1093/ofid/ofaa021. eCollection 2020 Jan.

Authors

Kai Ishimaru¹, Mari Sasaki², Hiroshi Narimatsu², Yoko Arimizu¹, Yasuhiro Gotoh¹, Keiji Nakamura¹, Tetsuya Hayashi¹, Yoshitoshi Ogura¹

Affiliations

¹ Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan.
² Section in Charge of Microbiology, Oita Prefectural Institute of Health and the Environment, Oita, Japan.

Abstract

No outbreaks caused by Escherichia coli-producing heat-labile enterotoxin LT2 have been reported to date. Here, we revealed that the E. coli O8:H8 strains isolated from patients in 2 independent diarrhea outbreaks were negative for any known virulence determinants in routine microbiological tests, were very closely related, and carried a prophage-encoded gene for a novel LT2 variant (LT2d) and the genes for colonization factor antigen III. We also showed that LT2d has a cytotonic activity similar to LT1. These data indicate the importance of E. coli strains producing LT2d as a human pathogen.

Keywords: colonization factor antigen; diarrhea outbreak; heat-labile enterotoxin; phage; scherichia coli.