Abstract: Objective To analyze the drug resistance and gene mutations of Mycobacterium tuberculosis in Meishan City from 2018 to 2022, and to provide references for the prevention and control of tuberculosis in Meishan City. Methods Gene chip technology was used for rapid screening of rifampicin (RIF) and isoniazid (INH) resistance. Multidrug-resistant (MDR) strains identified through screening were subjected to solid drug susceptibility testing (DST) for four drugs: streptomycin (SM), ethambutol (EMB), kanamycin (KM), and ofloxacin (OFLX). The results were analyzed descriptively. Results The overall drug resistance rate among 1 370 Mycobacterium tuberculosis strains was 11.75%. The monoresistance rates were 2.48% for RIF and 5.12% for INH, while the MDR rate was 4.16%. Significant differences were observed in the overall drug resistance rate, RIF monoresistance rate, and MDR rate between newly treated and retreated patients (P<0.05 or P<0.01). Among MDR patients, the resistance rates in descending order were SM>EMB>OFLX>KM, with the most common resistance type being SM + EMB (32.08%). The main mutation sites for RIF resistance-related gene rpoB were 531C-T (49.45%) and 511T-C (15.38%), while for INH resistance-related genes katG and inhA, the primary mutation sites were 315G-C (66.14%) and 15C-T (25.20%), respectively. The most common mutation combination in MDR strains was 531C-T + 315G-C (47.37%). Conclusions The drug resistance rate of tuberculosis in Meishan City is at an intermediate level within the province, with a declining trend in MDR rates. However, drug resistance among retreated patients remains severe, and the drug susceptibility profile of MDR strains is complex. The main mutation sites associated with RIF and INH resistance are high-level resistance sites.

Key words: Mycobacterium tuberculosis, gene chip, drug resistance, gene mutation, drug susceptibility testing