MTBDRplus方法快速检测结核分枝杆菌耐药性的研究

Evaluation of MTBDRplus assay for the rapid detection of isoniazid and rifampin drug resistance

目的评估聚合酶链反应（PCR）-分子线性探针杂交方法（MTBDRplus）检测结核分枝杆菌利福平和异烟肼耐药性的临床价值。方法利用线性探针杂交法检测120例结核分枝杆菌临床分离株和430例痰涂阳性标本，对耐药株进行基因分型；使用常规培养方法对痰样本进行分离培养和鉴定，并采用比例法对所有结核菌株进行抗结核药物敏感性测试。结果120例结核分离株比例法和线性探针杂交法检测利福平和异烟肼耐药率分别为18．3％（22／120）、25．0％（30／120）和16．7％（20／120）、23．3％（28／120），差异均无统计学意义（P〉0．05）；线性探针杂交法的敏感度和特异度分别为90．9％、100％和93．3％、100％。430例涂阳痰液标本中，经鉴定351例为结核分支杆菌，比例法和线性探针杂交法检测利福平和异烟肼耐药率分别为16．5％（58／351）、15．4％（54／351）和17．1％（60／351）、14．5％（51／351），差异均无统计学意义（P〉0．05）；线性探针杂交法的敏感度和特异度分别为89．7％、97．3％和83．33％、98．0％。合计471例结核菌株比例法和线性探针杂交法检测利福平和异烟肼耐药率分别为17．0％（80／471）、17．00％（80／471）和16．7％（84／471）、16．8％（79／471），差异均无统计学意义（P〉0．05）；线性探针杂交法的敏感度和特异度分别为90．0％、98．0％和86．9oA、98．5％。线性探针杂交法检测的耐药株中常见的突变型是katG-S315T1（15．3％）和rpoB-S531L（14．0％）。结论线性探针杂交法可快速、准确鉴定结核分枝杆菌并对常见耐药基因进行分型，适用于检测结核菌株和痰标本；可大幅缩短药物敏感试验周期，有利于临床及时用药治疗。

Objective To assess the new GenoTypeMTBDRplus assay for the rapid detection of isoniazid and rifampin drug resistance in comparison with conventional drug susceptibility test （DST） in clinical specimens. Methods A total of 120 stored mycobacterium tuberculosis isolates and 43O acid-fast bacilli （AFB）-positive sputum specimens were tested using both the conventional DST and the GenoTypeMTBDRplus assay. Results The rifampin （RFP） and isoniazid （INH） resistant were 18.3% （22/120） ,25. 0% （30/120） byDST and 16.7% （20/120）,23.3% （28/120） by GenoType assay in 120 stored isolates. No significant difference was detected between two methods （ P 〉0.05）. The GenoType assay had a sensitivity of 93.3% and 90.9% for INH and RFP resistance,and had a specificity of 100% for INH and RFP resistance in 120 stored isolates. The RMP and INH resistant were 16.5 % （58/a51）, 15.4% （54/351） by DST and 17.1% （60/351）,14.5% （51/351） by GenoType assay in 351 stored isolates. There was no significant difference between two methods （P 〉 0.05）. The sensitivity and specificity in sputum specimens for RFP and INH resistance was 89.7%,97.3% and 83.3%, 98.0% by using GenoType assay. In all 471 clinical specimens, the RFP and IN H resistant were 17.0 % （80/471）, 17.0% （80/471） by DST and 16.7% （84/471）, 16.8% （79/471） by GenoType assay. There was no significant difference between two methods. The sensitivity and specificity for RFP and INH resistance was 90.0%, 98.0% and 86.9%, 98.5M by using GenoType assay. The most common genotypes were katCr-S315T1 （15.3M） and rpoB-S531L （14.0%）. Conclusions The GenoType assay has been validated as a rapid and reliable diagnostic test on MTB isolates for INH and RFP resistance, especially for AFB- positive.