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Chinese Journal of Antituberculosis ›› 2026, Vol. 48 ›› Issue (4): 477-484.doi: 10.19982/j.issn.1000-6621.20250450

• Original Articles • Previous Articles     Next Articles

Genotypic and drug resistance of Mycobacterium tuberculosis in Beijing,2024

Miao Honghao1,2, Zhang Jie2, Pang Mengdi2, Ren Yixuan2, Deng Yang2, Yi Junli2, Fan Ruifang2, Chen Shuangshuang2, Chen Hao2, Yu Lan2, Li Jie1,2,3(), Li Chuanyou1,2,3(), Yang Xinyu1,2,3()   

  1. 1 School of Public Health,Capital Medical University,Beijing 100038,China
    2 Tuberculosis Laboratory,Beijing Center for Disease Prevention and Control,Beijing 100013,China
    3 Beijing Key Laboratory for Key Technologies in Tuberculosis Prevention and Control,Beijing 100035,China
  • Received:2025-11-12 Online:2026-04-10 Published:2026-04-02
  • Contact: Yang Xinyu,Email:yangxinyu@bjcdc.org;Li Chuanyou,Email:lichuanyou@ccmu.edu.cn;Li Jie,Email:lijie304304@163.com
  • Supported by:
    Fund Capital’s Funds for Health Improvement and Research(2024-2G-30114)

Abstract:

Objective:To characterize the genotypic characteristics and drug resistance features of Mycobacterium tuberculosis (MTB) clinical isolates from management of pulmonary tuberculosis (PTB) patients in Beijing in 2024,as well as the correlation between them,providing scientific evidence for tuberculosis prevention and control in Beijing. Methods:A total of 923 clinical isolates of MTB and their epidemiological data were systematically collected from registered PTB patients in Beijing Tuberculosis Prevention and Care System between January and December,2024 who met the study criteria. Polymerase chain reaction (PCR) was used for species identification of all strains. The Beijing genotype and non-Beijing genotype were identified using the RD105 deletion gene detection method,and ancient and modern Beijing genotypes were distinguished according to the integrity of the NTF region. Genotyping was conducted using 15-locus Mycobacterial Interspersed Repetitive Unit-Variable Number Tandem Repeat (MIRU-VNTR 15) analysis. The polymorphism and discriminatory power of each VNTR locus and the entire typing system were evaluated by the Hunter-Gaston Index (HGI) and the overall Hunter-Gaston Discriminatory Index (HGDI). Meanwhile,the clustering of genotypes was observed,and the minimum inhibitory concentration (MIC) method was used to perform drug susceptibility testing for 4 first-line and 4 Group A anti-tuberculosis drugs. Results:Species identification and genotyping results of 923 strains showed that there were 922 strains of MTB and 1 strain of Mycobacterium africanum. Among the MTB strains,the Beijing genotype accounted for 90.89% (838/922),mainly dominated by the modern type (85.20%,714/838). MIRU-VNTR genotyping revealed an HGDI value of 0.998,among which two loci,QUB11b (HGI=0.722) and QUB26 (HGI=0.639),exhibited high polymorphism and were key loci for distinguishing strains. All 230 clustered MTB strains were of the Beijing genotype,with a clustering rate of 24.95% (230/922),and 98.26% (226/230) of them were modern Beijing genotype. A total of 63 clusters were formed,and the largest cluster contained 29 strains,all of which were modern Beijing genotype. Drug resistance testing showed that isoniazid had the highest resistance rate (12.26% (113/922)),while ethambutol had the lowest (0.22%,2/922). The drug resistance rates of the Beijing genotype to isoniazid and levofloxacin (12.89% (108/838) and 9.79% (82/838),respectively) were significantly higher than those of the non-Beijing genotype (5.95% (5/84) and 2.38% (2/84),respectively). The modern type had a significantly lower drug resistantce rate to isoniazid (11.76% (84/714)) and rifampicin (5.18% (37/714)) than the ancient type (19.35% (24/124) and 11.29% (14/124)),with all differences being statistically significant (χ2=3.415,P=0.039;χ2=5.055,P=0.012;χ2=5.421,P=0.018;χ2=6.897,P=0.011). Conclusion:The modern Beijing genotype,characterized by high genetic diversity and transmission activity,is the dominant epidemic strain and the main genotype responsible for recent transmission of MTB in Beijing,with isoniazid resistance being the most prominent problem. Therefore,it is necessary to strengthen molecular monitoring and transmission chain tracing of modern Beijing genotype strains,especially for drug-resistant strains.

Key words: Mycobacterium tuberculosis, Genotyping, Tandem repeat sequences, Tuberculosis, multidrug-resistant

CLC Number: