Sporulation of Clostridium difficile in aerobic conditions is significantly protracted when exposed to sodium taurocholate

Abstract

Elimination of Clostridium difficile spores from the clinical setting requires stringent application of infection control procedures including the use of hard-surface disinfectants. A unique combination of sodium taurocholate together with amino acids has been reported as an alternative approach to potentially eliminating spores of C. difficile by increasing their sensitivity to common disinfectants. In this study, the efficacy of this spore germination solution was investigated to explore its effect on the sporulation process under aerobic conditions. Vegetative cells of C. difficile NCTC 11204 (Ribotype 001) and R20291 (Ribotype 027) were exposed to the germination solution comprising 6.9 mM sodium taurocholate and 50 mM of the following amino acids: histidine, glycine, arginine, aspartic acid, valine in TRIS buffer, and a control solution. Total viable counts, the rate and extent of sporulation, and percentage recovery of vegetative cells in both ribotypes were assessed by culture. At 24 hours, sporulation was protracted in ribotypes 001 and 027 and there were significantly more (p=<0.01) vegetative cells following exposure to the germination solution compared to those exposed to the control. No vegetative cells of either ribotype exposed to the control solution were detected at 24 hours. At 48 and 72 hours, vegetative cells of ribotype 027 were not detected however a significantly higher (p<0.001) percentage (43%) of viable vegetative cells of C. difficile 001 were recovered by culture. Exposing vegetative cells of C. difficile to a germination solution protracts the sporulation process in aerobic conditions. In previous studies, the application this solution to spores of C. difficile has been shown to initiate germination thus rendering them more sensitive to common disinfectants. In this investigation, the findings demonstrate that sodium taurocholate protracts the sporulation process and may provide an additional adjunct to future C. difficile infection control strategies.