DUAL INFECTION WITH ATTACHING AND EFFACING ESCHERICHIA-COLI AND ENTEROTOXIGENIC ESCHERICHIA-COLI IN POST-WEANING PIGS

Post-weaning diarrhoea in pigs occurred on two farms in Hokkaido, Japa n, in 1994. Four piglets aged 35 or 45 days were examined after death. At necropsy, ecchymotic haemorrhages were seen on the mucosal surface of the caecum and colon. Histopathologically, numerous Gram-negative bacilli adhered to the brush border of the small intestines, but the b rush border itself was intact. Typical attaching and effacing (AE) les ions were seen in the caecum and colon. Immunohistochemically, the bac illi which adhered to the brush border gave positive results with anti sera against serogroup O149 of Escherichia coli; the bacilli which cau sed the AE lesions, however, belonged to serogroup O45. It was conclud ed that the disease resulted from dual infection with attaching and ef facing E. coli (AEEC) and enterotoxigenic E. coli (ETEC). (C) 1996 W.B . Saunders Company Limited