Effect of filtrate containing Clostridium difficile toxin on rectal mucosa maintained in organ culture.

Rectal biopsies were maintained in organ culture over a 24-hour culture period, with good preservation of histological architecture. A filtrate containing Clostridium difficile toxin significantly inhibited the rise in epithelial alkaline phosphatase activity normally seen during culture. This effect was abolished by pre-incubation of the filtrate with Clostridium sordellii antitoxin, or heat inactivation. This effect is most probably due to a toxin of C. difficile. The method provides a new quantitative approach to the study of luminal toxins as possible pathogenic agents in idiopathic inflammatory diseases of the colon.