Figure 4.

Model C. Bacterial burden of C57BL/6 mice treated with rifampicin and isoniazid (RMP-INH) for 12 weeks after aerogenic infection with 30 colony-forming units (CFU) of Mycobacterium tuberculosis H37Rv. Two weeks postinfection, one group of mice (○) received 0·1 g/l RMP-INH, delivered in drinking water ad libitum (open arrows) for a period of 12 weeks, whereas the control group (•) received plain drinking water ad libitum. At specific time-points up to 44 weeks postinfection, the number of viable bacilli in the lung, spleen and liver were determined by plating organ homogenates and enumerating CFU. No viable bacilli were detected in the organs of mice after completion of chemotherapy. Mice treated with RMP-INH for 12 weeks and subsequently with aminoguanidine for 4 weeks (solid arrows) failed to reactivate infection. Results are expressed as means ± SEM and are representative of three independent experiments with three to four mice per group per time-point.