中文摘要：

目的：探讨Xpert MTB/RIF（Xpert）技术对结核分枝杆菌（MTB）及其利福平（RIF）耐药性检测的应用价值。方法：对310例抗酸染色阳性的痰标本分别进行Xpert检测、MTB-非结核分枝杆菌（NTM）核酸PCR检测（MTB-NTM-PCR）和罗氏培养,并将MTB阳性菌株作菌种鉴定和比例法药物敏感性试验,分析3种检测方法MTB阳性及阴性的符合情况;以比例法为金标准,计算Xpert检测RIF耐药性的灵敏度、特异度、准确度、阳性预测值和阴性预测值。结果：Xpert和MTB-NTM-PCR检测MTB阳性均为307例,二者符合率为100%;Xpert检测MTB阴性的3例标本,MTB-NTM-PCR检测为NTM;罗氏培养292例阳性,16例阴性,2例污染,Xpert检测MTB阴性的3例标本罗氏培养获得菌株进行对硝基苯甲酸（PNB）试验为阳性;以比例法为金标准,Xpert检测RIF耐药性的灵敏度、特异度、准确度、阳性预测值和阴性预测值分别为95.65%、95.94%、95.85%、91.67%和97.93%（P〉0.05,Kappa〉0.75）。结论：Xpert能快速准确的检测抗酸染色阳性痰标本中MTB及其RIF耐药性,对耐多药结核病（MDR-TB）的快速筛查具有重要价值。

英文摘要：

Objective：To evaluate the application of Xpert MTB/RIF（ Xpert） test in rapid detection of Mycobacterium tuberculosis（ MTB） and its resistance to rifampin（ RIF）. Methods：Xpert test,Mycobacterium nucleic acid test（ MTB-NTM-PCR）,and Lowenstein-Jensen culture method were conducted on 310 acid-fast staining positive sputum specimens,and the positive MTB strains isolated on Lowenstein-Jensen media were identified and their drug susceptibility was then determined by ratio sensitivity test. The test result accordance of the 3 methods were analyzed. Using ratio method as golden standard,the sensitivity,specificity,accuracy,positive predictive value and negative predictive value of the strains to RIF determined by Xpert test were calculated. Results：Of the 310 samples,307 cases were MTB positive determined by both Xpert and MTB-NTM-PCR,and the coincidence rate was100%. Three MTB negative samples detected by Xpert test were determined as Nontuberculosis mycobacteria（ NTM） by MTB-NTM-PCR test. In isolates by Lowenstein-Jensen media,292 samples were MTB positive,16 negative,and 2 were polluted. Three Xpert MTB negative samples were nitrobenzoic acid test positive determined by Lowenstein-Jensen media culture test. The sensitivity results determined by ratio method,specificity,accuracy,positive predictive value and negative predictive value of Xpert were 95. 65%,95. 94%,95. 85%,91. 67% and 97. 93% respectively. Analyzed with χ^2 and Kappa tests,the p value was higher than 0. 05 and the Kappa value was higher than 0. 75. Conclusions：Xpert can quickly determine MTB and its RIF drug resistance,which shows it has important value in fast screening of multi-drug resistant TB strains.