FIG. 4.

Survival profile of M. tuberculosis CDC1551, the ΔsigM mutant, and the ΔsigM-complemented strains in resting and activated J774A.1 murine macrophages. Macrophages were infected with wild-type (Wt), ΔsigM mutant (Mt), and ΔsigM-complemented (Com) strains. Macrophages were activated with IFN-γ and LPS before infection. The results are expressed as CFU/well in a 24-well plate, and data represent the average of three experiments. (A) Macrophages resting prior to infection. (B) Macrophages activated prior to infection. Error bars indicate standard deviations.