TRENDS IN PATHOTYPES AND ANTIMICROBIAL RESISTANCE OF ESCHERICHIA COLI ISOLATES FROM PIGLETS WITH POSTWEANING DIARRHEA IN QUEBEC

摘要

Enteric E. coli infection in weaned piglets may manifest as a diarrhea which usually occurs during the first week post-weaning. The pathogenic E. coli responsible for post-weaning diarrhea mostly belong to the ETEC category and the pathotypes associated with these ETEC may be different to those associated with neonatal diarrhea. Recently, a more severe form of enteric E. coli infection has been observed in Ontario and Quebec. This is observed in the first week following weaning, at two to three weeksfollowing weaning, or in some cases, following transfer of pigs to the grower units. It is manifested as sudden death or severe diarrhea, and is associated mostly with ETEC carrying the F4 (K88) adhesin. Most outbreaks have occurred in early weaned piglets although traditional herds are being increasingly affected. The factors contributing to the increased number of outbreaks of this more severe form of enteric E. coli infection are not yet known. In this study, we have examined trends in pathotype and antimicrobial resistance in E. coli isolates from pigs with post-weaning diarrhea in Quebec from 1994 to 1998.