耐异烟肼结核分枝杆菌的基因突变类型及表型异质性研究

Study on genetic mutation types and phenotypic heterogeneity of isoniazid-resistant Mycobacterium tuberculosis

目的了解河南省耐异烟肼结核分枝杆菌的相关基因突变类型。方法收集2016年—2020年河南省胸科医院Xpert MTB/RIF Ultra阳性的结核患者的痰标本,进行异烟肼药物敏感实验同时提取DNA,使用Sanger DNA测序方法检测突变基因型。结果199例患者中,药敏实验结果显示低异烟肼浓度(0.1μg/ml)耐药104例,高异烟肼浓度(0.4μg/ml)耐药90例;DNA测序结果显示96例DNA突变,其中75例为katG突变株,24例为inhA突变株,3株为katG和inhA联合突变。在这些突变株中主要突变位点为S315T(AGC/ACC)和-15(C/T),另外也发现了6株其他的突变位点。结论异烟肼耐药基因类型主要为katG和inhA,新的突变位点能为以后研发快速检测异烟肼耐药试剂盒提供依据。

Objective To understand the mutation types of isoniazid-resistant Mycobacterium tuberculosis in Henan Province.Methods Sputum samples of tuberculosis patients with Xpert MTB/RIF Ultra positive from 2016 to 2020 were collected,sensitivity test was carried out on isoniazid drug and DNA was extracted.SangerDNA sequencing method was used to detect the mutant genotype.Results Among the 199 cases,104 cases of low concentration of isoniazid(0.1μg/ml),90 cases of high isoniazid(0.4μg/ml)resistance and 96 cases of mutation were found by DNA sequencing,of which 75 were katG mutants,24 was inhA mutant,and 3 were katG and inhA mutations.The main mutation sites in these mutants were S315T(AGC/ACC)and-15(C/T),and 6 other mutation sites were also found.Conclusion The main genetic types of isoniazid resistance are katG and inhA,and some new mutation sites can also provide a basis for rapid detection of isoniazid resistance.