Typing of Mycobacterium tuberculosis strains resistant to rifampicin and isoniazid by molecular biological methods.

Mutations in the rpoB, katG, inhA, oxyR/ahpC genes in rifampicin- and isoniazid-resistant M. tuberculosis strains isolated from residents of Moscow, Astrakhan', and Moldova Republic were studied by molecular biological methods (heteroduplex analysis, single strand conformational polymorphism, biochips). Twenty-five combinations of mutations were detected.

[L-transformation of mycobacteria in the light of current epidemiological situation of tuberculosis in the world].

To determine a role of L-forms of Mycobacterium tuberculosis in the development of a recurrent tuberculous process in persons with residual pulmonary tuberculous changes, a total of 2,412 persons registered at a dispensary as those included into Groups VIIA and VIIB who were found to have a significant tuberculosis infection pool. The tuberculosis pathogen was detected in 214 (9%) examinees in the bacterial and L forms. A further follow-up of the persons whose pathological material had shown the L form which are prone to reverse indicated that the isolation of unstable mycobacterial L forms is an important predictive sign showing the high potential hazard of tuberculous process reactivation.

[Endogenous reactivation of tuberculosis as a result of reversion of persistent mycobacterial L-forms].

Detection of L-transformed variants of M. tuberculosis and the study of qualitative-quantitative characteristics of isolated mycobacterial population provided additional information to available clinical x-ray evidence on the followed up patients. This allows more accurate estimation of reactivation risk, indications to chemotherapy and correction of follow-up policy.

[Estimation of the degree of risk of reactivation of residual tuberculous changes based on the status of mycobacterial population].

The study was undertaken to define the role of L-forms of M. tuberculosis having different qualitative and ++quantitative characteristics in the development of recurrences of a tuberculosis process in subjects with residual tuberculous changes in the lungs. The microbiological and ++clinico-roentgenological+ examination included 2412 subjects who were in VIIA and VIIB Dispensary Groups.

[Clinical value of detection of L forms of Mycobacterium tuberculosis in patients with residual tuberculous changes in the lungs].

To clarify the role of M. tuberculosis L-form in a recurring tuberculous process in subjects with residual tuberculous changes in the lungs, microbiological, ++clinico-roentgenological and laboratory examinations of 1651 persons recorded as having VIIA, VIIB, III and 0 groups were undertaken. The causative agent of tuberculosis was isolated in a typical bacillary and L-transformed forms in 3.