<p>(<b>A</b>) Groups of 6 axenic mice were infected by oral gavage route with 1×10<sup>8 </sup><i>C. difficile</i> CFU. The <i>C. difficile</i> faecal vegetative cells and spores were measured by determining the concentration of CFU in faeces at 14 h post-infection by homogenising and plating on appropriated agar medium after heat shock (for spores) or not (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0096876#s4" target="_blank">Materials and Methods</a>). Data represent the ratio of spores per vegetative cells. (<b>B</b>) Cultures in BHIS broth in anaerobic conditions were prepared from 2 successive subcultures as indicated in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0096876#s4" target="_blank">Materials and Methods</a>. After heat shock, spores were quantified (CFU/ml) by performing serial dilutions and spread plating on BHIS agar supplemented with 0.1% bile salt taurocholate to induce germination. Data represent the ratio of spores per total cells. The presented values are the mean of 3 different cultures. Statistically significant difference is indicated by * for p<0,05.</p
