Pathogenicity of an Enterotoxigenic <i>Escherichia coli</i> Hemolysin ( <i>hlyA</i> ) Mutant in Gnotobiotic Piglets

Abstract

Pigs infected with hemolytic F4(+) strains of enterotoxigenic Escherichia coli often develop septicemia secondary to intestinal infection. We tested the hypothesis that inactivation of hemolysin would reduce the ability of F4(+) enterotoxigenic E. coli to cause septicemia in swine following oral inoculation. Inactivation of the hemolysin structural gene (hlyA) did not decrease the incidence of septicemia in the gnotobiotic piglet model.