(A) Intracellular bacteriolysis in immortalized Ifnar-/- macrophages. Macrophages were infected with the indicated strains carrying the pBHE573 reporter vector at an MOI of 10, and luciferase activity was measured 6 hours post-infection. Error bars indicate SEM; n = 4. *, P < 0.05 compared to wild type and #, P < 0.05 for the indicated comparison by one-way ANOVA with Tukey’s multiple comparisons test. (B) Plaque formation in immortalized murine fibroblasts (L2 cells). L2s were infected with the indicated strains at an MOI of ~0.5, plaques were stained on day 4 of infection, and sizes were normalized to those of wild type. Error bars indicate SEM; data are averaged from a minimum of 81 plaques from three biological replicates. N.D., not detected. *, P < 0.05 compared to wild type by one-way ANOVA with Tukey’s multiple comparisons test.