Reexamining the Germination Phenotypes of Several Clostridium difficile Strains Suggests Another Role for the CspC Germinant Receptor.

Clostridium difficile forms metabolically dormant spores that persist in the health care environment. In susceptible hosts, C. difficile spores germinate in response to certain bile acids and glycine. Blocking germination by C. difficile spores is an attractive strategy to prevent the initiation of disease or to block recurring infection. However, certain C. difficile strains have been identified whose spores germinate in the absence of bile acids or are not blocked by known inhibitors of C. difficile spore germination (calling into question the utility of such strategies). Here, we further investigate these strains and reestablish that bile acid activators and inhibitors of germination affect these strains and use these data to suggest another role for the C. difficile bile acid germinant receptor.