Cytotoxic effects of children's faeces: relation to diarrhoea due to Clostridium difficile and other enteric pathogens.

Cytotoxicity of faecal extracts was demonstrated in 47 of 88 children (54%) referred for microbiological investigation of stools. Cytotoxic Clostridium difficile and vertotoxigenic Escherichia coli (VTEC) were the pathogens identified most commonly but cytotoxicity was also found in association with Campylobacter jejuni, Salmonella spp, Shigella sonnei, Giardia lamblia, rotavirus, adenovirus and poliovirus type 1 which had been acquired by oral immunization. In two patients, one of whom had cystic fibrosis, cytotoxicity of faecal extracts was associated with isolation of Pseudomonas aeruginosa. In five of 13 patients with diarrhoea and cytotoxic C. difficile, other pathogens were also present, in agreement with the view that C. difficile are more readily recovered when the intestinal flora have been altered by colonization with other micro-organisms. There was no correlation between previous treatment with antibiotics and isolation of C. difficile. Cytotoxicity neutralized by antitoxin, usually to C. sordellii, is used to detect cytotoxic C. difficile. We suggest that cytotoxicity not neutralized in this way should be an indication for further investigation of stools for the presence of other pathogens such as VTEC or viruses.