Gastric attaching and effacing Escherichia coli lesions in a puppy with naturally occurring enteric colibacillosis and concurrent canine distemper virus infection.

A puppy suffering from chronic diarrhea was humanely killed at 90 days of age. Numerous Gram-negative bacilli were found adhering to the surface of as well as within epithelial cells from the stomach to the colon. Canine distemper virus inclusions were in the epithelial cytoplasm of the esophageal, gastric, and intestinal mucosa. Typical attaching and effacing ultrastructural lesions were in the stomach, and some bacilli were in the cytoplasm of the epithelial cells. Escherichia coli, isolated from the contents of the small intestine, belonged to serotype 0118: NM and were negative for plasmid-encoded EPEC adherence factor (EAF) and positive for the E. coli attaching effacing (eae) gene. Immunohistologically, bacilli attached to the epithelium from the stomach to the colon were positive for antisera against E. coli 0118. E. coli 0118: NM inoculated into human tissue culture cells (HEp-2 cells) were attached to the surface of the cells and within the cytoplasm. This is the first report of attaching and effacing E. coli (AEEC) infection in the stomach of the dog.