EXPERIMENTAL INOCULATION OF FOALS AND PIGS WITH AN ENTEROTOXIGENIC ESCHERICHIA-COLI ISOLATED FROM A FOAL

Hemolytic E. coli strain 807-13, O149:NM:K88(STb +, LT +), was isolate d from the feces of a neonatal diarrheic foal. E. coli 807-13 was exam ined for adhesion to brush border membranes (BBM) from foals, adult ho rses and pigs, and its pathogenicity was assessed in neonatal foals an d pigs. E. coli 807-13 did not adhere to equine BBM but adhered to pig BBM. It did not cause diarrhea nor did it colonize the intestinal epi thelium of 3 colostrum-deprived and 3 suckled foals challenged at 24 h of age. Acute ulcerative gastritis and acute suppurative gastritis we re observed in 2 colostrum-deprived challenged foals, and acute neutro philic enteritis was observed in 1 colostrum-deprived and in 1 suckled challenged foal. No similar histopathologic lesions were detected in the control foals. Both gnotobiotic and suckled pigs developed diarrhe a after challenge exposure to E. coli 807-13 and the intestinal epithe lium of the pigs was colonized. Histopathologic evidence of gastritis and enteritis among the foals indicated some complicity of E. coli 807 -13 in foal enteric disease.