Prevalence of some virulence factors among diarrheagenic Escherichia coli strains isolated from pigs in France.

Swine diarrheagenic E. coli strains isolated in France between January 1997 and August 1998 were serotyped and different virulence factors (LTa, STb, VT2e, F107) were tested by PCR. Thirty one percent of the strains were K88 and 31 % were untypeable with the sera commonly used in veterinary dignosti c laboratories. More than 60% of the strains possessed the STb gene and onl y 11% were VT2e positive and were classified as edema strains. Some results are in accordance to other European studies concerning prevalence of virul ence factors of swine ETEC and VTEC strains. To our knowledge, this work is the first French published study concerning prevalence of some virulence d eterminants among swine pathogenic E. coli.