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

Jinyun Zhao, Weifang Mao, Faxiang Jin, Wenfang Xu Department of Clinical Laboratory, Affiliated Hospital of Shaoxing University, Shaoxing, 312000, People’s Republic of ChinaCorrespondence: Jinyun Zhao, Department of Clinical Laboratory, Affiliated Hospital of Shaoxing University, 999 Zhongxing South Road, Yuecheng District, Shaoxing, 312000, People’s Republic of China, Tel +8618857568548, Email zjy19871987@163.comObjective: 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