Email Alert | RSS

Chinese Journal of Antituberculosis ›› 2026, Vol. 48 ›› Issue (5): 576-585.doi: 10.19982/j.issn.1000-6621.20250414

• Original Articles • Previous Articles     Next Articles

Molecular characterization and risk factors of cross-resistance between isoniazid and prothionamide in multidrug-resistant Mycobacterium tuberculosis in Ningbo, China

Che Yang1, Zhang Dongliang1, Li Xiangchen2, Lu Yewei2, Liu Zhengwei3()   

  1. 1Institute of Tuberculosis Prevention and Control, Ningbo Municipal Center for Disease Control and Prevention, Zhejiang Province, Ningbo 315010, China
    2Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research, Cosmos Wisdom Biotechnology Co., Ltd, Hangzhou 310020, China
    3The Institute of TB Control, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China
  • Received:2025-10-25 Online:2026-05-10 Published:2026-04-27
  • Contact: Liu Zhengwei E-mail:zhwliu@cdc.zj.cn
  • Supported by:
    Ningbo Public Welfare Science and Technology Program Project(2024S040);Ningbo Top Medical and Health Research Program(2023020713);Zhejiang Provincial Natural Science Foundation of China under Grant(LTGY23H190001)

Abstract:

Objective: This study aimed to investigate the characterization, the drug resistance-associated gene mutations in multidrug-resistant Mycobacterium tuberculosis (MDR-MTB) strains based on whole-genome sequencing (WGS) and to analyze the risk factors of cross-resistance between isoniazid (INH) and prothionamide (Pto). Methods: A total of 134 MDR-MTB isolates selected in the drug resistance survey in Ningbo between 2021 and 2024 were enrolled in the study. WGS was conducted to detect the genomic DNA extracted from clinical isolates. The sequencing data were analyzed using an in-house pipeline and the gene mutations determined based on MTB drug resistance gene database. The conventional drug susceptibility test was also used to detect the drug-resistant profiles against 9 antibiotics (levofloxacin, bedaquiline, linezolid, delamanid, clofazimine, amikacin, capreomycin, para-aminosalicylic acid and Pto). Combined with phenotypic drug susceptibility testing results and clinical data, the cross-resistance profile and risk factors between INH and Pto among MDR-MTB isolates were comprehensively analyzed. Results: Among 134 MDR-MTB isolates, 129 (96.3%, 129/134) carried INH resistance-associated mutations. Mutations were present in all three INH resistance-associated genes, katG, inhA and ahpC. The main mutation types were katG Ser315Thr (89.1%, 98/110), inhA c-15t (50.0%, 17/34) and ahpC c-81t (4/9). Among 134 MDR-MTB isolates, the overall Pto resistance rate (INH-Pto cross-resistance rate) was 20.2% (27/134), with 92.6% (25/27) harboring mutations. The gene mutations associated with Pto resistance were ethA and inhA, with mutation rates of 63.0% (17/27) and 77.8% (21/27), respectively. The major mutation types were ethA 11_12insA (70.6%, 12/17) and inhA t-8C (66.7%, 14/21). Among MDR-MTB and Pre-XDR-MTB, the INH-Pto cross-resistance rates were 20.2% (27/134) and 43.6% (24/55). Multivariate logistic regression showed that moxifloxacin given (OR (95%CI): 4.123 (1.207-14.080)) and the resistance of levofloxacin (OR (95%CI): 0.075 (0.019-0.293)) were risk factors for INH-Pto cross-resistance. Conclusion: The prevalence of INH-Pto cross-resistance among MDR-MTB was serious in Ningbo and the mutation type inhA t-8C was closely with INH-Pto cross-resistance. The regimen for INH-Pto cross-resistant patients should be according to the drug susceptibility results of fluoroquinolones and choose optimal treatment.

Key words: Mycobacterium tuberculosis, Drug resistance, multiple, bacterial, Prothionamide, Mutation, Genes

CLC Number: