Drug resistance pattern of Mycobacterium tuberculosis in seropositive and seronegative HIV-TB patients in Pune, India.

BACKGROUND & OBJECTIVE Tuberculosis is the commonest opportunistic disease in persons infected with human immunodeficiency virus (HIV). Emergence of drug resistant isolates of M. tuberculosis highlights the need for continuous monitoring of drug resistance to antituberculosis drugs. Considering the reported high prevalence of drug resistance in HIV infected tuberculosis patients, we studied the anti-tuberculosis drug resistance pattern of M. tuberculosis in HIV seropositive and seronegative tuberculosis patients in Pune, Maharashtra, India. METHODS A total of 70 M. tuberculosis isolates, 30 from HIV seropositive and 40 from HIV seronegative tuberculosis patients with no previous history of anti-tuberculosis treatment, were isolated from sputum samples on Lowenstein-Jensen (LJ) medium, confirmed by conventional biochemical tests and stored at -70 degrees C. They were revived by subculturing on LJ medium and tested for drug resistance against four first-line antitubercular drugs by BACTEC Mycobacterial growth indicator tube 960 (MGIT 960) system. RESULTS Of the 30 isolates from HIV infected patients, 10 per cent were resistant to isoniazid (H), 6.6 per cent to streptomycin (S), 6.6 per cent to ethambutol (E) and 10 per cent were multi drug resistant (MDR). Of the 40 M. tuberculosis isolates from HIV uninfected individuals, 10 per cent were resistant to H, 2.5 per cent to S, 2.5 per cent to E, and 2.5 per cent isolates were MDR. INTERPRETATION & CONCLUSION The prevalence of drug resistant M. tuberculosis isolates among HIV seropositive tuberculosis patients was similar to that of HIV seronegative TB patients, indicating HIV infection may not be associated with drug resistant tuberculosis. However, considering the results from other studies and a high prevalence of HIV-TB infection in the country, monitoring of drug resistance in M. tuberculosis isolates needs prioritization to ensure success in national tuberculosis control programme.