FIG 7.
TFP promote association of C. difficile with the cecal epithelium. Mice were coinoculated with ∼105 spores each of 630Δerm and pilB1 mutant. Ceca were harvested anaerobically at day 3 postinoculation. Cecal contents and a 1-ml wash of PBS were combined into the luminal fraction. The tissue-associated fraction was obtained by homogenizing the remaining cecum. Serial dilutions of the luminal and tissue-associated fractions were plated on TCCFA (all C. difficile cells) and TCCFA with erythromycin (mutant C. difficile) to determine the bacterial burden of each strain. Symbols represent CI (mutant to parent) values from individual animals, and error bars indicate the standard deviations. Data were analyzed by the Wilcoxon rank sum test comparing the CI in the luminal fraction to the CI in the tissue-associated fraction. **, P < 0.01.