应用GeneXpert MTB/RIF对耐多药MTB及RIF耐药性的快速检测

Application of GeneXpert MTB/RIF in rapid detection of multidrug-resistant Mycobacterium tuberculosis and rifampicin resistance

目的探讨利福平耐药实时荧光定量PCR(GeneXpert)结核分枝杆菌(MTB)/利福平(RIF)技术在检测MTB、耐多药MTB(MDR-TB)及RIF耐药性方面的作用。方法选取2015年12月-2016年7月在医院就诊的520例疑似肺结核病患者,对其痰标本分别进行金胺"O"荧光染色镜检、液体培养及药敏试验、罗氏培养及比例法药敏试验和Xpert法检测。结果 520例疑似肺结核患者中,共确诊387例肺结核,其中男性确诊率77.14%,女性确诊率68.82%;除痰涂片镜检外,其他三种方法检测MTB的敏感性均高于40.00%,四种方法的特异性均高于90.00%;其中,Xpert检测的敏感性明显高于痰涂片镜检(P<0.01),而与罗氏培养和MGIT培养均无统计学差异(两者敏感性分别为41.86%和45.22%);RIF耐药性试验显示,肺结核分枝杆菌对RIF的耐药率低于10.00%;GeneXpert MTB/RIF检测RIF的耐药率与比例法和液体药敏相比,差异无统计学意义;以比例法为金标准,检测出31株MDR-TB,GeneXpert MTB/RIF对MDR-TB的检出率达到86.11%。结论 Xpert法适用于MTB及其对RIF耐药性的快速筛查;同时可作为检测MDR-TB的一种指标。

OBJECTIVE To evaluate the role of GeneXpert MTB/RIF in detection of Mycobacterium tuberculosis（MTB）,multidrug-resistant M.tuberculosis（MDR-TB）and rifampin（RIF）resistance.METHODS A total of 520 cases of suspected tuberculosis patients were chosen from Dec.2015 to Jul.2016 in hospital,the sputum samples were collected to do auramine ＂ O＂ fluorescent staining,mycobacterial growth indicator tube（MGIT）culture,Lwenstein-Jensen culture,drug susceptibility test and Xpert assay.RESULTS Totally 387 patients were diagnosed with tuberculosis,and the positive rate of male was 77.14% and female was 68.82%.The sensitivity of these methods were higher than 40.00%except sputum smear microscopy,and their specificity were all higher than 90.00%.The sensitivity of Xpert assay was significantly higher than sputum smear microscopy（P〈0.01）,but there was no signifiant difference of testing results between Xpert assay and culture（solid and liquid culture）（their sensitivity were respectively 41.86% and 45.22%）.RIF drug resistance test showed that the RIF resistant rate of MTB were all less than 10.00%,and there was no signifiant difference of testing results between Xpert MTB/RIF assay and drug susceptibility test.Total of 31 strains of MDR-TB were detected,and the rate of MDR-TB detected by GeneXpert MTB/RIF was 86.11% with traditional proportion method as golden standard.CONCLUSION Xpert assay is suitable for detection of tuberculosis and RIF resistance rapidly,and is also suitable for detection of MDR-TB as an indicator.