海南地区484株结核分枝杆菌菌株基因型特征分析

目的 了解海南地区结核分枝杆菌不同基因型流行特征,探讨基因分型用于评价本地区结核病控制中的应用价值。方法 本研究选取海南医学院第二附属医院自2013-2016年所有培养阳性结核分枝杆菌484株,采用SNP和Gao等推荐的12位点可变数目串联重复序列（variable number tandem repeat, VNTR）进行基因分型。结果 2013-2016年期间,484株结核分枝杆菌菌株中,北京基因型菌株279株,占57.6%,非北京基因型菌株205株,占42.4%,北京基因型菌株中包括91株(32.6%)古代北京基因型和188株(67.4%)现代北京基因型。北京基因型所占比例在四年间无显著变化,从2013年的59.6%到2016年的57.6%。采用3个高变VNTR位点基因分型后,成簇菌株数为0。结论 海南地区结核分枝杆菌存在明显的VNTR基因多态性,主要流行株仍以北京基因型为主,北京基因型所占比例在四年期间无显著性变化,且菌株成簇率较低,提示近期传播率低。

Genotype prevalence of 484 strains of Mycobacterium tuberculosis in Hainan

Objective To explore the distribution of different Mycobacterium tuberculosis (MTB) genotypes in Hainan, and to investigate the application value of genotyping to assess the strategy of TB control and prevention in this region. Methods A total of 484 MTB isolates were enrolled from Hainan Tuberculosis Hospital during 2013 to 2016. SNP and 12-locus variable number tandem repeat(VNTR) endorsed by Gao were used for genotyping these MTB isolates. Results From 2013 to 2016, of all MTB isolates, 279 belonged to Beijing genotypes, accounting for 57.6%, and the other 205 were classified as non-Beijing genotypes (42.4%). In addition, there were 91 strains(32.6%) of ancient Beijing genotype and 188 strains (67.4%) of modern Beijing genotype isolates, respectively. The proportion of Beijing genotype strains was not significantly increased in the past four years (59.6% in 2013 vs. 57.6% in 2016). On the basis of three high variable VNTR loci, there were no cluster strains. Conclusions There was obvious VNTR gene polymorphism in M．tuberculosis isolates in Hainan. Beijng family was the main epidemic strains, in which the modem type was predominant with no significant change in four years. In addition, the low clustering rate indicates that most of TB cases are not contributed to the recent transmission.