Ingestion of Mtb by MØ. Resting and IFN-γ-activated MØ were infected with FITC-labeled wild-type or ∆kstD strains for 2 hours. (A) Percentage of MØ infected with Mtb strains; (B) Percentage distribution of MØ with the counted number of bacteria engulfed by one phagocyte (per MØ). Percentage of infected MØ was calculated according to the formula: MØ with bacteria *100/ number of counted MØ and expressed as means ± SEMs (n = 5). Mtb ops – bacteria opsonized, Mtb non-ops – bacteria non-opsonized.