Attaching and Effacing Escherichia coli Infections in Calves, Pigs, Lambs, and Dogs

Abstract

Attaching and effacing Escherichia coli (AEEC) adhere to mucosal epithelium in both small and large intestine and induce a distinctive lesion characterized by an irregular scalloped appearance of the epithelial layer. Infection with attaching and effacing E. coli was detected in 14 calves, 7 pigs, 2 lambs, and 3 dogs. Affected animals were from farms and kennels in South Dakota, Minnesota, Iowa, Nebraska, and Wisconsin. Ages of affected animals were calves, 2 days to 4 months; pigs, 1–6 weeks; lambs, 1 week; and dogs, 7–8 weeks. Clinical signs included diarrhea in all animals, but other nonenteric disease problems were present in some animals. Concurrent infection with other enteropathogens was detected in 9 calves and 5 pigs. Infection with AEEC appeared to be the sole cause of illness and death in some animals. There was evidence of intestinal hemorrhage in 5 of the calves and in all 3 dogs. Attaching and effacing lesions varied from small scattered foci to widespread involvement of large areas of intestinal mucosa. Verotoxin was produced by E. coli strains isolated from 9 calves, but not by strains from pigs, lambs, or dogs.