[Experimental evidence for Mycobacterium tuberculosis persistence in M. tuberculosis-infected H37RV mice in the treatment with 3 first-line drugs (rifampicin, isoniazid, pyrazinamide)].
To detect Mycobacterium tuberculosis (MBT) DNA in the blood and organs of tuberculosis-infected animals treated by the standard regimen including 3 first-line drugs, to assess the cellular reactions of organs of MBT-infected mice, and to evaluate the effect of rifampicin supplemented to the Cornell treatment regimen on the occurrence of endogenous reactivation of a tuberculous process, 150 BALB/c mice were intravenously infected with the MTB H(3)7Rv strain in a dose of 2.5 x 10(4) CFU/mouse and given chemotherapy with 3 drugs: rifampicin, 12 mg/kg body weight, isoniazid, 5 mg/kg, and pyrazinamide, 35 mg/kg. On day 20 of infection 2, 4, and 6 months after treatment and 2 months after termination of 4- and 6-month courses of therapy, the authors made inoculation, impressionsmears from parenchymatous organs stained by the Romanovsky-Gimse method, and conducted polymerase chain reaction for MBT DNA in the blood and organs of mice. The results indicated that supplementation of rifampicin to the Cornell treatment regimen prevented endogenous reactivation of the process, as confirmed by negative inoculations of the organs of the mice left untreated for 2 months. However, detection of MBT DNA and the cytological picture characteristic of tuberculous inflammation in the blood and organs of mice from these groups suggested that an occult tuberculous process was preserved.