The genetic diversity of drug resistance in Mycobacterium tuberculosis strains from the Tibetan Plateau

OBJECTIVE: This study aimed to characterize the genetic diversity of drug resistance in Mycobacterium tuberculosis (MTB) isolates from the Tibetan Plateau, elucidate the molecular epidemiological profile of tuberculosis (TB) in this high-altitude region, and offer a molecular basis to guide improved diagnostic, therapeutic, and preventive strategies. METHODS: A total of 169 clinical MTB isolates were collected from the General Hospital of Xizang Military Command between January 2024 and April 2025. Drug resistance-associated mutations were identified via targeted gene sequencing. RESULTS: Among the 169 isolates, the overall rate of genotypic resistance was 20.71 %, comprising mono-resistance (14.79 %), poly-resistance (1.78 %), and multidrug-resistance (MDR, 4.14 %). Retreated patients exhibited a higher resistance rate than newly treated cases (26.09 % vs. 14.29 %), with MDR exclusively identified in the retreatment group. Resistance to streptomycin was most prevalent (8.28 %), followed by isoniazid (7.69 %) and rifampicin (7.10 %). The predominant mutations observed were rpsL K43R and katG S315T. No mutations conferring resistance to second-line drugs were detected. CONCLUSION: The substantial burden of drug-resistant TB on the Tibetan Plateau-particularly streptomycin resistance-underscores the critical need for implementing precision diagnostics and optimizing therapeutic regimens.