Time-dependent survival of Mtb in MØ. Resting MØ were infected with wild-type or ∆kstD strains for 2 hours. On the day of infection and after 2, 4 or 6 days in culture, MØ were lysed with Triton X-100 and cell lysates were plated onto agar plates. After 21 days of culture, CFUs/ml were counted. The data are presented as fold increase in CFUs/ml, expressed as means ± SEMs (n = 3). Mtb ops – bacteria opsonized, Mtb non-ops – bacteria non-opsonized.