A role for the Clostridium perfringens β2 toxin in bovine enterotoxaemia? (original) (raw)

Non-enterotoxigenic type A Clostridium perfringens are associated with bovine enterotoxaemia, but the a toxin is not regarded as responsible for the production of typical lesions of necrotic and haemorrhagic enteritis. The purpose of this study was to investigate the putative role of the more recently described b2 toxin. Seven hundred and fourteen non-enterotoxigenic type A C. perfringens isolated from 133 calves with lesions of enterotoxaemia and high clostridial cell counts (study population) and 386 isolated from a control population of 87 calves were tested by a colony hybridisation assay for the b2 toxin. Two hundred and eighteen (31%) C. perfringens isolated from 83 calves (62%) of the study population and 113 (29%) C. perfringens isolated from 51 calves (59%) of the control population tested positive with the b2 probe. Pure and mixed cultures of four C. perfringens (one ab2, one aenterotoxin and two a) were tested in the ligated loop assay in one calf. Macroscopic haemorrhages of the intestinal wall, necrosis and haemorrhages of the intestinal content, and microscopic lesions of necrosis and polymorphonuclear and mononuclear cell in®ltration of the intestinal villi were more pronounced in loops inoculated with the a and b2-toxigenic C. perfringens isolate. These results suggest in vivo synergistic role of the a and b2 toxins in the production of necrotic and haemorrhagic lesions of the small intestine in cases of Veterinary Microbiology 86 (2002) 191±202