Figure 4. Nanocompartment mutants are attenuated for survival in macrophages and are more susceptible to pyrazinamide (PZA) treatment.

CFU enumeration of wild-type Mtb and (A) Δoperon or (B) DyP::Tn mutants during infection of murine bone marrow-derived macrophages. Macrophages were infected with a bacterial MOI of 1, and CFUs were enumerated immediately following phagocytosis and at days 2 and 4. Error bars are SD from four replicate wells. (C) CFU enumeration of wild-type and Mtb Δoperon mutants following 72 hr exposure to PZA (24 μg/mL) and H₂O₂ (2.5 mM) in acidified 7H9 medium (pH 5.5). Comp = Δoperon + pOperon. (D) Infection of BALB/C mice with WT and Δoperon mutant with and without treatment with 150 mg/kg PZA. CFU at 35 days post infection in the lung is shown. (A) and (B) are representative of at least five independent experiments; (C) is representative of three experiments and (D) is representative of two experiments. p-Values were determined using an unpaired t-test. **p<0.01; ***p<0.001.