Department of Bacteriology and Immunology, Beijing Key Laboratory on Drug-Resistant Tuberculosis Research, Beijing Tuberculosis and Thoracic Tumor Research Institute/Beijing Chest Hospital, Capital Medical University, Beijing, 101149, China.
BMC Infect Dis. 2018 Dec 14;18(1):658. doi: 10.1186/s12879-018-3578-7.
The most prevalent strains of Mycobacterium tuberculosis (M.tb) in Beijing belong to the Beijing genotype family. The influence of Beijing genotype prevalence on the development of drug resistance, and the association of infection with Beijing genotype M.tb with population characteristics, in Beijing, however, are still unclear.
In this retrospective study, 1189 isolates were subjected to drug susceptibility testing (DST) and molecular epidemiological analysis, and differences in the percentage of drug resistance between Beijing and non-Beijing genotype strains were compared. The association between the occurrence of drug resistance and the prevalence of Beijing genotype M.tb was analyzed using statistical methods.
The Beijing genotype family was the dominant genotype (83.3%) among the 1189 M.tb isolates. Beijing genotype M.tb strains were more likely to spread among males [p = 0.018, OR (95% CI):1.127(1.004-1.264)] and people in the 45-64 age group [p = 0.016, OR (95% CI): 1.438 (1.027-2.015)]. On the contrary, non-Beijing genotype M.tb strains were more probably disseminated among the over 65 [p = 0.005, OR (95% CI):0.653 (0.474-0.9)] and non-resident population [p = 0.035, OR (95% CI):1.185(0.985-1.427)]. DST results showed that 849 (71.4%) strains were fully sensitive to first-line drugs, while 340 (28.6%) strains were resistant to at least one drug, and 9% (107/1189) were MDR-TB. The frequency of INH-resistance among Beijing genotype strains was significantly lower than that among non-Beijing genotype strains (p = 0.032). In addition, the Beijing genotype family readily formed clusters.
Our findings indicate that male and middle-aged people were more probably be infected by Beijing genotype M.tb, older people and non-residents were more probably be infected by non-Beijing genotype M.tb. The high percentage of resistance to INH occurring in non-Beijing genotype strains suggested that non-Beijing genotype strains should be given much more interest in Beijing.
北京地区最流行的结核分枝杆菌（M.tb）菌株属于北京基因型家族。然而，北京基因型流行率对耐药性发展的影响，以及北京基因型 M.tb 感染与人群特征的关系，在北京仍不清楚。
在这项回顾性研究中，对 1189 株分离物进行了药物敏感性试验（DST）和分子流行病学分析，并比较了北京基因型和非北京基因型菌株的耐药百分比差异。采用统计学方法分析耐药性的发生与北京基因型 M.tb 流行率之间的关系。
1189 株 M.tb 分离物中，北京基因型家族是主要基因型（83.3%）。北京基因型 M.tb 菌株更容易在男性中传播[P=0.018，比值比（95%可信区间）：1.127（1.004-1.264）]和 45-64 岁年龄组人群中传播[P=0.016，比值比（95%可信区间）：1.438（1.027-2.015）]。相反，非北京基因型 M.tb 菌株更容易在 65 岁以上人群[P=0.005，比值比（95%可信区间）：0.653（0.474-0.9）]和非本地居民中传播[P=0.035，比值比（95%可信区间）：1.185（0.985-1.427）]。DST 结果显示，849（71.4%）株对一线药物完全敏感，340（28.6%）株至少对一种药物耐药，9%（107/1189）为 MDR-TB。北京基因型菌株中 INH 耐药的频率明显低于非北京基因型菌株（P=0.032）。此外，北京基因型家族易于形成聚类。
我们的研究结果表明，男性和中年人群更有可能感染北京基因型 M.tb，老年人和非本地居民更有可能感染非北京基因型 M.tb。非北京基因型菌株对 INH 的高耐药率表明，非北京基因型菌株在北京更值得关注。
