Veterinary and Biomedical Sciences, Department of


Date of this Version

October 1998


Published in INFECTION AND IMMUNITY, Oct. 1998, p. 5031–5035 Vol. 66, No. 10. Copyright © 1998, American Society for Microbiology. Used by permission.


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.