FIG 4.

selD plays a role in outgrowth of C. difficile R20291 spores. Purified C. difficile R20291 (wild-type) (●), C. difficile KNM6 (ΔselD) (■), and C. difficile KNM9 (ΔselD::selD⁺) (▲) spores were germinated and then resuspended in BHIS (A) or TY (B) medium, and the OD₆₀₀ was measured over an 8-h period and then again at 24 h. Data points represent the average from three independent experiments and error bars represent the standard deviation from the mean. Statistical significance was determined using a two-way ANOVA with Tukey’s multiple-comparison test (*, P ≤ 0.05). Only time points in which comparisons between R20291 versus KNM6 and KNM6 versus KNM9 were both significant are labeled.