FIG. 3.

Effect of the BclA protein on virulence in the mouse infection model. (A) BALB/c mice were challenged intranasally with spores of the Ames wild-type strain (○) or the bclA strain (Δ). (B) The effect of the bclA mutation on the rate of spore clearance from mouse lungs. Mice were exposed to an aerosolized inoculum of spores of both wild-type Ames and bclA mutant. The number of heat-resistant (65°C for 30 min) spores retained within the lungs at designated time points was determined by bacterial counts on selective and nonselective media. The error bars represent standard errors of the means. *, P = 0.03; **, P = 0.0005.