河南省结核菌分离株26位点MIRU-VNTR和Spoligotyping分子分型及耐药分析

目的 探讨河南省结核杆菌的遗传多样性。方法 使用26位点（经典24位点和其他2位点）的分支杆菌散在重复单元中数目可变串联重复序列（mycobacterium interspersed repetitive unit-variable number tandem repeat，MIRU-VNTR）和间隔区寡核苷酸分型（spoligotyping）对来自2015年期间河南省不同地区的668株结核杆菌分离株进行分型分析。对结核菌spoligotype类型和耐药表型的相关性进行分析。结果 Spoligotyping分析表明668株结核杆菌被分到10个不同的基因簇中。北京家族基因型是河南地区结核杆菌中的优势菌株。北京家族基因型菌株对四种一线药全耐药以及耐多药菌株比例明显高于非北京型菌株。668株结核杆菌通过26位点VNTR被分为567个不同的基因型。26个位点中15个位点具有高度或适中的分辨能力。10个分辨能力最强位点的组合分辨力能与26位点相当。结论 北京家族是河南省最流行的结核杆菌基因型。10位点VNTR和spoligotyping相结合可有效地用于河南省结核杆菌进化遗传学研究。

Characterization of Mycobacterium tuberculosis isolates from Henan Province by genotyping and drug susceptibility tests

Objective To explore the genetic profile of tuberculosis from Henan. Methods 668 MTB isolates from various areas during 2015 were genotyped with spoligotyping and 26-locus mycobacterium interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) (classical 24-locus MIRU-VNTR and 2 other loci). The association between tuberculosis spoligotype signatures and drug-resistant profiles was analyzed. Results Spoligotyping data revealed 668 isolates were grouped into 10 different clusters. Beijing family was the most predominant genotype in Henan. There was no correlation between Beijing family and gender, age at diagnosis and treatment history, however, Beijing family had a higher proportion of resistance to all four first-line drug and multidrug-resistant phenotypes. 668 isolates were divided into 567 different types by 26-locus MIRU-VNTR analysis. For these samples, 15 of 26 MIRU-VNTR loci had highly or moderately discriminatory power according to the Hunter-Gaston discriminatory index. A combination of the 10 most polymorphic loci acquired similar discriminatory power to that of 26-locus set. Conclusions Beijing genotype is the most prevalent family. 10-locus MIRU-VNTR in combination with spoligotyping can efficiently investigate evolutionary genetics of MTB in Henan Province.