Monospecific antibodies for detection of Clostridium difficile enterotoxin.

Tests of polyclonal antisera to homogeneous enterotoxin preparations of Clostridium difficile by immunoblotting demonstrated that cross-reactions occurred with proteins from cell lysates of nearly all Clostridium species. There was a notable reduction in the amount of crossreaction when only culture supernatants were analysed. The enterotoxin could be easily identified by its unique high molecular weight of 230,000. The findings suggest that care must be taken when immunological tests other than immunoblotting are used for detection of Clostridium difficile enterotoxin.