Dawson LF et al. - Two C. difficile hypervirulent 027 strains (Stoke Mandeville and BI-16) are more tolerant to p-cresol than other C. difficile strains including 630, CF4 and CD196. Surprising, it was shown that Clostridium sordellii also has a high tolerance to p-cresol, suggesting an overlap in the tolerance pathways in these clostridial species.