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

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.
Funding Information
  • JSPS KAKENHI (16H06279, 17H04077, 16H05190)
  • AMED (JP17efk0108127h0002, 18fk0108065h0801)