[Morphologic changes in the intestine of swine after infection with verotoxin-producing Escherichia coli]

Spontaneous morphologic lesions are described in 12 of 66 pigs submitted for necropsy. All 12 pigs were culture positive for Verotoxin-producing E. coli (VTEC). 10 of them were weaned pigs, one a suckling piglet and one a fattening hog. In 6 cases E. coli serovar 0139:H1 and in one case each the serovars 0139:H40; 0138:H-; 0125ac:H27 and 0154:H- were isolated. From the fecal samples of 2 animals E. coli ONT (O-group non typable):H- were cultured. Macroscopically there were cyanosis, edema of the eye lids, catarrhal enteritis and/or colitis as well as edema of the mesentery, swelling of the mesenteric lymph nodes and congestion of the lung to varying degrees. Histopathologic examination of 5 animals was carried out. In 3 animals atrophy and edema of the villi in the jejunum and ileum were discovered. In one animal an additional infection with corona virus was confirmed electron microscopically. Furthermore there was disseminated necrosis of lymphocytes in Peyer's patches of the small intestine and in secondary follicles of the mesenteric lymph nodes. In one of the animals a hemorrhagic-necrotising ileitis, occurred characterized by necrosis of villi and thrombosis of blood vessels in the mucosa. The highest number of VTEC with seven out of twelve animals was found in weaned pigs in association with the E. coli serovar 0139.