FIG. 5.

Effects of sigM deletion on the virulence of M. tuberculosis in the mouse model of infection. Lung (A) and spleen (B) CFU counts and time-to-death analysis (C) in C57BL/6 mice infected with wild-type (Wt), ΔsigM mutant (Mt), and ΔsigM-complemented (Com) strains of M. tuberculosis by the aerosol route. Groups of six infected mice were evaluated for CFU counts at each time point. Groups of 20 mice were infected for time-to-death analysis; of these, three from each group of infected mice were sacrificed on day 1 (shown as week 1/7) to determine the initial lung CFU counts. Error bars indicate standard deviations.