二代线性探针技术在结核分枝杆菌耐药性检测中的价值

目的 评价二代线性探针技术(GenoType MTBDRplus VER 2.0,简称“GenoType 2.0”)快速检测结核分枝杆菌(MTB)临床分离株对异烟肼与利福平耐药性的临床应用价值。方法 收集2017年4月至2019年4月天津市结核病控制中心参比实验室中疑似肺结核患者的痰标本共6315份,纳入涂阳、培阳且经菌群鉴定为MTB的349 株菌株为研究对象,分别采用表型药物敏感性试验(简称“比例法药敏试验”)和GenoType 2.0检测菌株对利福平、异烟肼的耐药性;并以比例法药敏试验结果为参考标准,评价GenoType 2.0的检测效能。结果 GenoType 2.0、比例法药敏试验和GenoType 2.0+比例法药敏试验检测349株MTB菌株对利福平敏感、单耐、耐利福平+异烟肼菌株的检出率分别为86.53%(302/349)、87.97%(307/349)、86.25%(301/349),2.58%(9/349)、2.29%(8/349)、2.29%(8/349),10.89%(38/349)、9.74%(34/349)、11.46%(40/349),前者与后两者及后两者对敏感、单耐、耐利福平+异烟肼菌株检出率差异均无统计学意义(χ²=0.322,P=0.851;χ²=0.112,P=0.946;χ²=0.546,P=0.761);对异烟肼敏感、单耐、耐利福平+异烟肼菌株的检出率分别为79.94%(279/349)、80.23%(280/349)、79.65%(278/349),9.17%(32/349)、9.46%(33/349)、9.46%(33/349),10.89%(38/349)、10.32%(36/349)、10.89%(38/349),前者与后两者及后两者对敏感、单耐、耐利福平+异烟肼菌株检出率差异均无统计学意义(χ²=0.071,P=0.965;χ²=0.017,P=0.991;χ²=0.061,P=0.970)。以比例法药敏试验为参考标准,GenoType 2.0对利福平和异烟肼耐药性检测的敏感度、特异度、符合率、Kappa值分别为91.67%(44/48)和95.89%(70/73)、99.00%(298/301)和100.00%(276/276)、97.99%(342/349)和99.14%(346/349)、0.91和0.97。结论 GenoType 2.0对于利福平和异烟肼的耐药性检测具有较高的敏感度和特异度,加上其检测周期较短,可以满足临床对结核病早期诊断和及时治疗的需求。

Detection value of the second-generation linear probe technique for drug resistance in Mycobacterium tuberculosis culture-positive isolates

Objective To evaluate the clinical application value of second-generation linear probe technique (GenoType MTBDRplus VER 2.0, called “GenoType 2.0”) for rapid detection of resistance to isoniazid (INH) and rifampicin (RFP) in clinical isolates of Mycobacterium tuberculosis (MTB). Methods A total of 6315 sputum specimens from suspected tuberculosis patients in the reference laboratory of Tianjin Tuberculosis Control Center from April 2017 to April 2019 were collected, and 349 strains identified as MTB by smear positive, culture positive and flora positive were served as the research objects. Conventional drug susceptibility testing (DST) and GenoType 2.0 assay were, respectively, used to detect resistance to RFP and INH of culturing-positive specimens. Based on DST as the reference standard, the detection efficiency of GenoType 2.0 assay were evaluated. Results The detection rates of RFP-sensitive, single resistance to RFP and multi-drug resistance to RFP and INH were 86.53% (302/349), 87.97% (307/349) and 86.25% (301/349) in GenoType 2.0; 2.58% (9/349), 2.29% (8/349) and 2.29% (8/349) in DST; and 10.89% (38/349), 9.74% (34/349) and 11.46% (40/349) in GenoType 2.0+DST, respectively, all the comparisons between GenoType 2.0 and DST, GenoType 2.0+DST and GenoType 2.0 or GenoType 2.0+DST and DST did not assign statistical significance (χ²=0.322, P=0.851; χ²=0.112, P=0.946; χ²=0.546, P=0.761). The detection rates of INH-sensitive, single resistance to INH and multidrug resistance to RFP and INH were 79.94% (279/349), 80.23% (280/349) and 79.65% (278/349) in GenoType 2.0; 9.17% (32/349), 9.46% (33/349) and 9.46% (33/349) in DST; and 10.89% (38/349), 10.32% (36/349) and 10.89% (38/349) in GenoType 2.0+DST, respectively, all the comparisons between GenoType 2.0 and DST, GenoType 2.0+DST and GenoType 2.0 or GenoType 2.0+DST and DST did not assign statistical significance (χ²=0.071, P=0.965; χ²=0.017, P=0.991; χ²= 0.061, P=0.970). Compared with DST, the sensitivity, specificity, coincidence rate, Kappa value of GenoType 2.0 to RFP and INH resistance tests were 91.67% (44/48) and 95.89% (70/73), 99.00% (298/301) and 100.00% (276/276), 97.99% (342/349) and 99.14% (346/349), 0.91 and 0.97, respectively. Conclusion The GenoType 2.0 assay has high sensitivity and specificity as well as shorter detection period for the detection of RFP and INH resistance, and thus it can meet the needs of clinical early diagnosis and timely treatment of tuberculosis.