Murine model of acute TB infection

8- to 10-week-old female specific pathogen–free C57BL/6-Ifng^tm1Ts mice (interferon gamma receptor knockout mice [GKO]) were purchased from Jackson Laboratories. The mice were infected with M. tuberculosis Erdman (TMCC 107) via a low-dose aerosol exposure in a Glas-Col aerosol generation device (Glas-Col Inc.) as described previously (Lenaerts et al, 2005). At 1 d post-aerosol, three mice were sacrificed to verify the uptake of ∼100 CFU of M. tuberculosis Erdman per mouse. Each treatment group consisted of five mice, and treatment was started at 14 d post-aerosol infection and continued for 9 consecutive days. Five infected mice were sacrificed at the start of treatment as pretreatment controls. Drugs were administered daily by oral gavage in a volume of 200 µl per mouse. For endpoint analysis, the mice were euthanized one day following the end of treatment, and the lungs and spleens were collected. The left lung lobe or whole spleens were homogenized for enumeration of CFU by plating dilutions of the organ homogenates on Middlebrook 7H11 medium supplemented 10% vol/vol OADC, 0.03 mg/ml cycloheximide, and 0.05 mg/ml carbenicillin. The data were expressed as mean log10 CFU ± the SEM for each group.