徐州市耐多药结核耐药分析及分枝杆菌基因突变特征研究

目的 研究徐州市耐多药结核(MDR-TB)耐药表型、耐INH或RFP相关基因突变情况,分析耐药表型与基因突变间关系,为耐多药结核疾病的诊断提供科学依据。方法 采取随机方法抽取徐州市115例MDR-TB菌株和66株全敏感菌株进行耐药情况分析,使用基因芯片检测技术对耐INH相关基因katG、 inhA和aphC以及耐RFP相关基因rpoB突变位点进行检测,对结果进行t检验分析。结果 徐州市MDR-TB菌株耐药表型有9种组合,主要是以耐INH+RFP组合为主,比例为47.83%,其次为耐INH+RFP+SM组合,比例为20.00%。与耐INH的相关基因突变率87.83%,基因突变类型分别为单基因katG(64.35%)和inhA(3.48%),双基因katG+inhA(12.17%)和katG+aphC(12.17%)。耐多药株(115例)和敏感株(66例)总体变异率均数比较(t=107.56,P<0.05), 其中katG基因突变率比较(P<0.05),二者差异均有统计学意义。与耐RFP相关rpoB基因总突变率86.09%,耐RFP相关rpoB基因突变类型分别为单531(45.22%)、516(8.70%) 和526位点,双(531+516)(13.91%)、(531+513)(12.17%)和516+533突变位点, 531+516+513(3.48%)三位点突变。耐多药株和敏感株总体和单个位点突变率均数比较(t=94.92,P<0.05), 531(P<0.05)、516(P<0.05)、533(P<0.05),二者差异均有统计学意义。结论 研究发现了徐州市MDR-TB耐药表型特征。徐州市MDR-TB菌株与耐INH和RFP相关基因突变客观存在,并表现出多态性和地区性。与耐INH相关katG基因、与耐RFP的相关rpoB基因531、516、533位点突变相对稳定,有临床应用价值,可作为徐州市耐药结核菌株快速诊断的指标。

Drug-resistance analysis and characteristics of gene mutations in multiple drug-resistant tuberculosis in Xuzhou,China

This article focused on studying the spectrum of multiple drug-resistant tuberculosis (MDR.tuberculosis) isolates and gene mutations in MDR.tuberculosis isolates in Xuzhou. We sought to identify molecular evidence supporting a rapid diagnostic method for MDR.tuberculosis through analyzing the relationships between the spectra of MDR.tuberculosis isolates and mutations in MDR.tuberculosis isolate genes. A total of 115 MDR.tuberculosis isolates and 66 pan-susceptible isolates were chosen via random sampling from the entire Xuzhou area. We used the gene chip technique to detect the ropB gene in RFP-resistant MDR.tuberculosis and katG, inhA and aphC of INH-resistant MDR.tuberculosis; the results were analyzed with t-tests. Nine spectra of MDR.tuberculosis treated with six drugs were identified; the most prevalent spectrum was that of INH+RFP, accounting for 47.83%, followed by INH+RFP+SM, accounting for 20.00%. Among the mutations in drug resistance genes of MDR.tuberculosis treated with INH (87.83%), 64.35% had mutations in katG, 3.48% had mutations in inhA, 12.17% had mutations in katG+inhA, and 12.17% had mutations in katG+aphc. The total mutation rate in MDR.tuberculosis isolates (115) was higher than that in pan-susceptible isolates (66) treated with INH, and the difference was statistically significant (t=107.56,P<0.05). For the other mutations, only the difference in the mutation rate in katG was statistically significant (P<0.05). The rpoB gene mutation rate of drug resistance genes in MDR.tuberculosis treated with RFP was 86.09%. The locations of mutations were at codons 531 (45.22%), 516 (8.70%), 531+516 (13.91%), 531+513 (12.17%) and 531+516+513 (3.48%), whereas 526,533 and 516+533 codon mutations were quite rare. The total mutation rate of MDR.tuberculosis isolates under RFP treatment (115) was higher than that of pan-susceptible isolates (66), and the difference was statistically significant (t=94.92, P<0.05). For the other mutations, only the difference in the mutation rate in codons 531 and 516 was statistically significant (P<0.05). Mutations under INH and RFP treatment of MDR.tuberculosis were evident and showed polymorphism and regionalism in Xuzhou. The common mutation sites in MDR.tuberculosis treated with RFP were mainly codons 531, 516 and 533; the mutation site with INH treatment was most commonly katG, which was relatively stable and may serve as a rapid and effective index for early diagnosis of MDR.tuberculosis in Xuzhou.