Bile acid sensitivity and in vivo virulence of clinical Clostridium difficile isolates

•Clostridium difficile isolates collected from patients cause a range of disease in mice.•These isolates exhibit variable tolerance to secondary bile acids in vitro.•Tolerance to lithocholic acid is associated with higher disease scores in mice.

Clostridium difficile is an anaerobic bacterium that causes diarrheal illnesses. Disease onset is linked with exposure to oral antibiotics and consequent depletion of secondary bile acids. Here we investigate the relationship between in vitro secondary bile acid tolerance and in vivo disease scores of diverse C. difficile strains in mice.