Improved recovery of Clostridium difficile spores with the incorporation of synthetic taurocholate in cycloserine-cefoxitin-fructose agar (CCFA)

Aim: Culture remains important for the detection and typing of Clostridium difficile. Culture of C. difficile spores can be enhanced on media supplemented with a germinant. Despite this, unsupplemented media continues to be used in some laboratories. The aim of this study was to quantify the effect of the known germinant sodium taurocholate on recovery of C. difficile spores and to determine if the supplement impacts on the recovery of vegetative C. difficile. Methods: The recovery on cycloserine-cefoxitin-fructose agar (CCFA) with and without taurocholate, of spore, vegetative, and total cell fractions of broth cultures of eight C. difficile isolates was compared. Results: Taurocholate in CCFA did not inhibit growth of vegetative C. difficile and significantly increased recovery of spores (p=0.04). Conclusions: The routine incorporation of taurocholate in CCFA is recommended for improved sensitivity in C. difficile culture from specimens.