FIG 5 .

mc²7901- and mc²7902-derived MDR strains grow slower than parental strains in vitro and are killed by second-line TB drugs or nutrient starvation. (A) Log-phase cultures were diluted 1/100, and growth was followed by recording optical density at 600 nm. Mean with standard deviation is plotted (n = 2). (B) RAW 264.7 macrophages were infected at an MOI of 1. At the indicated time points, macrophages were lysed to determine bacterial titers. PLAM was added to the macrophage growth medium, and the medium was changed at each time point. (C) PLAM-supplemented log-phase cultures of mc²7901, mc²7902, mc²8248, and mc²8251 were treated with EOK (ethionamide [25 mg/liter], ofloxacin [5 mg/liter], kanamycin [20 mg/liter]). (D) Log-phase cultures of mc²7901, mc²7902, mc²8248, and mc²8251 were washed five times in PBS and resuspended in Middlebrook 7H9-OADC-glycerol-tyloxapol containing PLAM (dilution factor 1/100) or not. In experiments in panels B, C, and D, the strains were initially grown in Middlebrook 7H9-OADC-glycerol-tyloxapol-PLAM. Samples were taken at the indicated time points, diluted, and plated for CFU on Middlebrook 7H10-OADC-glycerol-PLAM plates. Means with standard deviations are plotted (n = 3).