Characterization of Drug Resistance Patterns, Mutation Profiles and Prevalence of Mycobacterium tuberculosis in Shaoxing

Objective: This study aimed to analyze drug resistance patterns, mutation profiles in Mycobacterium tuberculosis isolates and clinical characteristics of tuberculosis patients in Shaoxing, Zhejiang, China. Methods: Clinical specimens and data from tuberculosis patients admitted in 2024 were collected. Cultures were established using the MGIT liquid culture system, and drug susceptibility to twelve anti-tuberculosis agents (four first-line and eight second-line) was assessed by the microbroth dilution method. Mutations in the rpoB gene, katG gene, and inhA promoter were identified using a DNA microarray chip assay. Results: Among 268 Mycobacterium tuberculosis isolates, 62 (23.1%) exhibited resistance to at least one anti-tuberculosis drug. These comprised 21 (7.8%) mono-resistant, 25 (9.3%) poly-resistant, and 16 (6.0%) multidrug-resistant strains, including 3 (1.1%) classified as pre-extensively drug-resistant and 1 (0.4%) as extensively drug-resistant. Among rifampicin-resistant isolates, mutations at codons 531 (47.4%) and 526 (21.1%) of the rpoB gene were most frequent, while the katG Ser315Thr substitution was detected in 44.8% of isoniazid-resistant strains. Compared with primary cases, re-treated patients were more frequently over 50 years of age, exhibited a higher prevalence of pulmonary cavities, and showed significantly elevated rates of drug resistance (P < 0.05). Conclusion: Our findings indicate that although the overall prevalence of drug-resistant tuberculosis in Shaoxing remains low, the resistance patterns are heterogeneous. These results underscore the need for comprehensive drug susceptibility and genetic testing to guide effective treatment strategies. Keywords: Mycobacterium tuberculosis , multidrug resistance, drug sensitivity test, DNA microarray, clinical characteristics