Xpert MTB/RIF系统快速检测结核分枝杆菌及利福平耐药性研究

Evaluation of the Gene Xpert MTB/RIF for rapid detection of mycobacterium tuberculosis and rifampin resistance

目的探讨Xpert MTB/RIF快速检测系统在结核病诊断及利福平耐药性检测中的价值。方法收集2012年12月-2013年12月在新疆医科大学第一附属医院和乌鲁木齐市胸科医院住院的疑似肺结核患者312例的痰液标本,同时进行涂片抗酸杆菌检查和用罗氏固体培养基进行结核杆菌培养,用比例法进行药物敏感性试验,并用Xpert MTB/RIF系统进行结核分枝杆菌DNA及利福平耐药性检测,结果 312例痰液标本中,涂片和培养均阳性的124例患者XpertMTB/RIF检测的敏感度为94.3%(117/124),涂片阴性而培养阳性者的敏感度为92.8%(26/28),涂片阴性而符合临床标准者XpertMTB/RIF检测的敏感度为47.6%(10/21),与培养结果比较,XpertMTB/RIF检测的总敏感度为94.1%(143/152);增加检测的次数(2次检测)可将灵敏度提高到98.7%%;对非结核病患者XpertMTB/RIF检测的特异度为99.3%(138/139)。与比例法相比,Xpert MTB/RIF检测利福平耐药的灵敏度为90.9%(10/11),特异度为99.3%(140/141)。除涂片阴性者外,Xpert MTB/RIF半定量检测结果与涂片结果有较好的一致性。结论 Xpert MTB/RIF系统检测结核分枝杆菌及利福平耐药性具有较高的临床应用价值,且方法简便、快速。

Objective To investigate the clinical value of Xpert MTB/RIF fast testing system for detection of Mycobacterium tuberculosis and rifampin resistance.Methods 312 patients with suspected pulmonary tuberculosis in the First Affiliated Hospital of Xinjiang Medical University and Urumqi Chest Hospital were selected from December 2012 to December 2012,and their sputum specimens were collected.Smear acid fast bacilli examination and cultivation on solid medium （egg-based Lwenstein-Jensen）were per-formed simultaneously,the drug sensitivity test was carried out using the proportion method,at the same time the Gene Xpert MTB/RIF system was used to detect Mycobacterium tuberculosis DNA and Rifampin resistance.Results Among 312 cases of sputum specimens,124 cases were smear positive and culture pos-itive,in which the sensitivity of Xpert MTB/RIF was 94.3%（117/124）,and the sensitivity for patients with smear-negative and culture positive was 92.8% （26/28）.In cases with bacteriological negative but meet the clinical standard,the sensitivity of Xpert MTB/RIF was 47.6% （10/21）.Compared with the cul-ture results,the total sensitivity of Xpert MTB/RIF detection was 94.1% （143/152）.The sensitivity can be improved to 98.7%% if increase the detection time （two times）.The test was specific in 138 of 139 pa-tients without tuberculosis （99.3%）.As compared with phenotypic drug-susceptibility testing,Xpert MTB/RIF testing correctly identified 10 of 11 patients （90.9%）with Rifampin-resistant bacteria and 140 of 141 （99.3%）with Rifampin-sensitive bacteria.In addition to smear negative patients,semi quantitative results of XpertMTB/RIF detection were consistent with the microscopic examination.Conclusion Xpert MTB/RIF system has high value for detection of Mycobacterium tuberculosis and Rifampin resistance , and the method is simple and fast.Plasma.