噬菌体生物扩增法快速测定结核分枝杆菌利福平耐药性

目的　建立快速测定结核分枝杆菌利福平耐药性的噬菌体生物扩增法 ,并探讨其在结核分枝杆菌利福平耐药性测定中的应用价值。方法　应用噬菌体生物扩增法测定 5 2 4株结核分枝杆菌利福平耐药性 ,并与绝对浓度法结果进行比较 ,对不符合的菌株采用BactecMGIT 96 0测定其最低抑菌浓度 (MIC)。结果　噬菌体法测定 5 2 4株结核分枝杆菌临床分离株利福平敏感 30 1株、耐药 2 2 3株 ,绝对浓度法敏感 313株、耐药 2 11株 ;两法测定均为敏感 2 88株、均为耐药 198株。在 38株噬菌体法与绝对浓度法测定结果不符的菌株中 ,35株噬菌体法与MIC测定结果相符合。如以绝对浓度法药敏结果为判断标准 ,则噬菌体法测定利福平耐药性的敏感性为 93 8%、特异性为 92 0 %、阳性预测值为88 8%、阴性预测值为 95 7%、准确性为 92 7%。结论　噬菌体生物扩增法测定利福平耐药性只需 2天时间 ,操作简便 ,不需特殊仪器设备 ,可作为结核分枝杆菌利福平耐药性的快速筛选方法。

Application of rapid detection for rifampin resistance in clinical isolates of Mycobacterium tuberculosis by phage amplified biologically assay

Objective To set up a rapid detection method for rifampin susceptibility with phage amplified biologically (PhaB) assay and to evaluates its value in the detection of rifampin resistance in clinical isolates of Mycobacterium tuberculosis Methods The assay was established to detect rifampin resistance in 524 clinical isolates of Mycobacterium tuberculosis , and the result was compared to that of the absolute concentration method The minimum inhibitory concentration (MIC) was detected by BACTEC MGIT 960 method for the discrepant isolates Results Rifampin susceptibility results were available for 524 strains of Mycobacterium tuberculosis A total of 223 strains were found to be rifampin resistant and 301 strains were rifampin susceptible detected by PhaB assay, but 211 and 313 strains were respectively found to be rifampin resistant and susceptible by conventional methods There were 198 and 288 rifampin resistant and susceptible strains both detected by the two methods The drug susceptibility of 35 strains was the same in 38 discrepant isolates by the PhaB assay and absolute concentration method The sensitivity, specificity, positive and negative predictive values as well as the overall accuracy for the PhaB assay was 93 8%, 92 0%, 88 8%,95 7% and 92 7% respectively if the judgment standard was adopted by conventional methods Conclusion The result of PhaB assay was available within 2 days This method, which is simple and does not need special equipment, can be used for rapid screening for rifampin resistance from Mycobacterium tuberculosis