Bacteriology and Pathology of Natural Infection in Calves with Attaching and EffacingEscherichia coli

Abstract

Seven fatal cases of natural infection with attaching and effacingEscherichia coli (E. coli) in 3- to 40-day old calves occurring in Shiga Prefecture from 1991 to 1993 were investigated pathologically and bacteriologically. Diarrhea was seen in 5 of 7 cases, and histopathology and electron microscopy revealed that numerous colibacilli adhered to the colon enterocytes and the effacing of epithelial microvilli in all cases. AllE. coliisolates possessed theeaegene, but not EAF, producing verotoxin 1. The isolates were of O26: H11 (4 cases), O118: H16 (2 cases) and O103: H2 (1 case).