Virulence characterization of strain Escherichia coli - BK99

In order to evaluate the pathogenicity and antimicrobial resistance pattern of BK99 E. coli strain, several tests were assessed: slide agglutination for detection of the fimbriae F5, STa production, hemolytic and colicin activity, pathogenicity assessement using piglet inoculation and antimicrobial resistance to drugs. The strain BK99 showed the following profile: F1+, F5+, STa+, Col V+, Hly-, ST R, KA R, NO R, TT R SF R. It produced clinical disease and death of infected piglets. Moreover, it was possible to recover the BK99 strain from diarrheic feces and from the gut contents of the piglet, with high rate of recovery of colonies expressing fimbriae F5+. The present results suggest that the E. coli BK99 strain could produce virulence factors and experimentally reproduce neonatal colibacillosis in pigs.

diarrhoea; piglets; colibacillosis; virulence factors