Zhang Dan, An Jun, Wang Yufeng, Pang Yu
Yongchuan Hospital, Chongqing Medical University, Chongqing, China; National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention, No. 155, Changbai Road, Changping District, Beijing, 102206, China.
Tuberculosis and Thoracic Tumor Research Institute, Beijing Chest Hospital, Capital Medical University, Beijing, China.
Int J Infect Dis. 2014 Dec;29:7-11. doi: 10.1016/j.ijid.2014.05.020. Epub 2014 Oct 13.
To gain an insight into the genetic diversity of multidrug-resistant (MDR) Mycobacterium tuberculosis isolates in Chongqing Municipality, an MDR tuberculosis (MDR-TB) epidemic region of China.
In this study, a total of 208M. tuberculosis isolates from smear-positive TB patients in Chongqing were genotyped by spoligotyping and mycobacterial interspersed repetitive unit-variable number tandem repeat typing (MIRU-VNTR). In addition, statistical analysis was performed to evaluate the distributions of drug susceptibility patterns and demographic data among different genotypes.
Our results showed that 156 MDR M. tuberculosis strains (75.0%) belonged to the Beijing genotype, while the other 52 strains (25.0%) were non-Beijing genotype. The proportion of Beijing genotype in the re-treated patient group was significantly higher than that in the new patient group (p=0.013), while drug resistance and demographic characteristics showed no statistically significant associations with Beijing genotype (p>0.05). In addition, the 208 strains were clustered into 193 genotypes using a 10-locus VNTR set; the cumulative clustering rate was 12.98% and the HGDI was 0.9991.
Beijing genotype was the predominant genotype among the isolates from MDR-TB cases in Chongqing. The re-treated MDR-TB cases were more likely to be attributed to Beijing genotype infection. The 10-locus VNTR set demonstrated a good discrimination power for genotyping MDR M. tuberculosis isolates circulating in Chongqing Municipality.
深入了解中国耐多药结核病（MDR-TB）流行地区重庆市耐多药结核分枝杆菌分离株的遗传多样性。
本研究采用间隔寡核苷酸分型（spoligotyping）和分枝杆菌插入重复单位可变数目串联重复序列分型（MIRU-VNTR）技术，对重庆市208株涂片阳性肺结核患者的结核分枝杆菌分离株进行基因分型。此外，进行统计分析以评估不同基因型之间药物敏感性模式和人口统计学数据的分布情况。
结果显示，156株耐多药结核分枝杆菌菌株（75.0%）属于北京基因型，其余52株（25.0%）为非北京基因型。复治患者组中北京基因型的比例显著高于新患者组（p=0.013），而耐药性和人口统计学特征与北京基因型无统计学显著关联（p>0.05）。此外，使用10个位点的VNTR组合将208株菌株聚类为193种基因型；累积聚类率为12.98%，HGDI为0.9991。
北京基因型是重庆市耐多药结核病病例分离株中的主要基因型。耐多药复治结核病病例更可能归因于北京基因型感染。10个位点的VNTR组合对重庆市流行的耐多药结核分枝杆菌分离株基因分型具有良好的鉴别能力。
