FIG. 8.

The loss of htrA exacerbates ΔprsA2-associated bacterial viability defects within infected host cells. (A) Bacterial growth in BHI broth was determined via optical density measurements at 600 nm. The data shown represent results from one of three independent experiments, each performed in duplicate. (B) J774 macrophage-like cells were infected at an MOI of 0.1 bacterium to 1 macrophage, and bacterial intracellular growth was measured in the presence of gentamicin at the indicated time points. Data shown are the averages of results from three independent experiments. •, wild type; ○, ΔprsA2 mutant; X, ΔhtrA mutant; ♦, ΔprsA1 ΔprsA2 mutant; ▾, ΔhtrA ΔprsA2 mutant; ▿, ΔhtrA ΔprsA2 plus pPL2-prsA2 mutant. Statistical significance was determined using one-way analysis of variance with Tukey's multiple comparison test (*, P < 0.01; **, P < 0.001).