FIG. 3.

L. monocytogenes chitinase mutants are defective for growth in the livers and spleens of infected mice. ND4 Swiss Webster mice were infected via tail injection (2) with 2 × 10⁴ CFU of wild-type, ΔchiA, ΔchiB, Δlmo2467, and ΔchiA bacteria complemented with plasmid-borne chiA (ΔchiA+pPL2-chiA). After 72 h of infection, the animals were euthanized and the bacterial burdens were measured in the livers (A) and spleens (B). A minimum of 5 mice were inoculated per strain tested, and the mean and standard deviation are shown. Statistical significance was determined using one-way analysis of variance with Tukey's multiple-comparison test (*, P < 0.01; **, P < 0.001; ***, P < 0.0001).