Drug resistance characteristics of Mycobacterium tuberculosis isolates to four first-line antituberculous drugs from tuberculosis patients with AIDS in Beijing, China

• The total drug resistance rate, initial drug resistance rate, acquired drug resistance rate for the TB in people with AIDS group were significantly higher than those for the TB without HIV infection group.
• These suggested that HIV infection might be one of the risk factors of drug-resistant TB infection.
• The two groups had the same order of drug resistance rates to H > S > R > E, which differed from the results reported by Tabarsi; however, there may be regional differences.

The objective of this study was to investigate the drug resistance characteristics of Mycobacterium tuberculosis isolates to four first-line antituberculous drugs (ATDs) from tuberculosis (TB) patients with AIDS in Beijing, China. All M. tuberculosis strains were isolated from specimens from TB patients with AIDS hospitalised between April 2010 and October 2012. Isolates were cultured by mycobacterial culture methods and were identified by multilocus PCR. Drug sensitivity testing was performed by the proportion method with the following first-line ATDs: isoniazid; rifampicin; streptomycin; and ethambutol. Results were compared with the drug resistance status of M. tuberculosis strains isolated from TB patients without HIV infection in Beijing. Among 41 M. tuberculosis isolates from TB patients with AIDS, the rates of total drug resistance (58.5%), initial drug resistance (46.7%) and acquired drug resistance (90.9%) were significantly higher than in TB patients without HIV infection (34.1%, 24.5% and 48.5%, respectively; P < 0.05). In TB patients with AIDS, the rates of acquired drug resistance (90.9%) and acquired multidrug-resistant TB (MDR-TB) (54.5%) were significantly higher than the rates of initial drug resistance (46.7%) and initial MDR-TB (10.0%) (P < 0.05). In patients with TB without HIV infection, the rate of acquired drug resistance (48.5%) was significantly higher than the rate of initial drug resistance (24.5%) (P < 0.05). M. tuberculosis drug resistance in TB patients with AIDS is significantly more serious than in TB patients without HIV infection. These results showed that more attention should be paid to M. tuberculosis drug resistance in AIDS patients.