FIG. 5.

Colonization by the ΔyapE mutant during mixed infection with WT CO92. Mice were infected subcutaneously in the neck with a 1:1 mixture of the ΔyapE mutant and ΔlacZ WT (open symbols) or the yapE complemented mutant and ΔlacZ WT (gray symbols). Lymph nodes (circles), spleen (squares), and lungs (triangles) were harvested at 24, 36, 48, and 60 h postinfection. Serial dilutions were plated on agar containing X-Gal to differentiate between the test and ΔlacZ WT strains, and CFU of each were determined. The ratio of recovered mutant bacteria to ΔlacZ WT was compared to the equivalent ratio of the inocula to generate a competitive index (C.I.) score. Median competitive index scores are represented by black bars. Scores less than one indicate attenuation in colonization by the test strain.