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

No outbreaks caused by -producing heat-labile enterotoxin LT2 have been reported to date. Here, we revealed that the 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.