Xpert MTB/RIF在脊柱结核诊断及利福平耐药检测中的应用价值

目的:探讨Xpert MTB/RIF技术在脊柱结核诊断及利福平耐药检测中的应用价值。方法:选取109例初步诊断为脊柱结核患者的脓液标本,分别行抗酸染色、BACTEC MGIT 960液体快速培养和Xpert MTB/RIF试验,对比3种检测结核分枝杆菌的敏感性及特异性的差异。对不同方法获取的脓液标本行Xpert MTB/RIF检测,评估脓液标本本身对Xpert MTB/RIF检测结核分枝杆菌效能的影响。以BACTEC MGIT 960液体快速培养药敏试验结果为金标准,分析Xpert MTB/RIF检测利福平耐药的效能。结果:抗酸染色、BACTEC MGIT 960液体快速培养及Xpert MTB/RIF检测的总体敏感性分别为25.92%、48.15%和77.78%。Xpert MTB/RIF检测开放手术、B超定位穿刺和穿刺活检取得脓液标本的敏感性分别为83.78%、76.47%和44.68%。以BACTEC MGIT 960液体快速培养药敏试验结果为金标准,Xpert MTB/RIF检测利福平耐药的敏感性和特异度分别为80%(4/5)和90.70%(39/43)。结论:Xpert MTB/RIF试验对脊柱结核具有较高的诊断价值,同时能对利福平耐药菌株进行检测,脓液标本中结核分枝杆菌含量对Xpert MTB/RIF检测的敏感性影响较大。

Application value of Xpert MTB/RIF in diagnosis of spinal tuberculosis and detection of rifampin resistance

Objective: To investigate the application value of Xpert MTB/RIF in diagnosis of spinal tuberculosis and detection of rifampin resistance. Methods: The 109 pus specimens were obtained from patients who were primaryly diagnosed as spinal tuberculosis. All of the pus specimens were detected by acid-fast stain,liquid fast culturing by BACTEC MGIT 960 and Xpert MTB/RIF assay to definite the differences in sensitivity and specificity of mycobacterium tuberculosis among detecting methods. Pus specimens obtained by different methods were deteceded by MTB/RIF test to analyze the self-influence on Xpert MTB/RIF test. The result of liquid fast culturing by BACTEC MGIT 960 was used as the gold standard;and the value of Xpert MTB/RIF assay in detecting rifampin resistance was analyzed. Results: The sensitivity of acid-fast stain,liquid fast culturing by BACTEC MGIT 960 and Xpert MTB/RIF assay were 25.92%,48.15%,77.78%,respectively. The sensitivity of pus specimens obtained from open surgery,ultrasound positioning puncture and biopsy the sensitivity were 83.78%,76.47%,44.68% respectively deteceded by MTB/RIF test. According to the gold standard of the results of liquid fast culturing by BACTEC MGIT 960 assay,the sensitivity and specificity of Xpert MTB/RIF assay in detecting rifampin resistance were 80%(4/5) and 90.70%(39/43),respectively. Conclusion: Xpert MTB/RIF assay has higher value in diagnosis of spinal tuberculosi,and also can detect rifampin resistance. The number of mycobacterium tuberculosis in pus specimens has a great influence in the sensitivity of Xpert MTB/RIF assay.