We have demonstrated that long-term exposure of intact mice to rifampicin (6 months) induces resistance to this drug, which manifested in inability of rifampicin to suppress the growth of Mycobacterium tuberculosis in the lungs and spleen during subsequent infection. It the same time, isoniazid is still effective in these mice. In this case, the phenomenon of somatic resistance to rifampicin in mice was observed if the treatment was started in a short period (within 4 days) after infection with M. tuberculosis. If the interval between infection and rifampicin administration was longer (3 weeks), the resistance disappeared.

中文翻译：

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实验性结核病小鼠体细胞对利福平的耐药性

我们已经证明，完整小鼠长期暴露于利福平（6 个月）会诱导对该药物产生耐药性，这表现为利福平在随后的感染过程中无法抑制肺和脾中结核分枝杆菌的生长。同时，异烟肼对这些小鼠仍然有效。在这种情况下，如果在感染结核分枝杆菌后的短时间内（4天内）开始治疗，则观察到小鼠体内对利福平产生抗药性的现象。如果感染和利福平给药之间的间隔较长（3周），则耐药性消失。