Comparison of three molecular assays for detection of rifampin resistance in Mycobacterium tuberculosis / 中华临床感染病杂志

ABSTRACT

Objective:To evaluate the diagnostic effects of Xpert MTB/RIF, Fluorescence PCR melting curve and gene chip technology for rapid screening of rifampicin-resistant tuberculosis.Methods:The clinical data of 150 patients diagnosed with tuberculosis by Bactec MGIT 960 liquid culture drug susceptibility in Zhejiang Chinese Medicine and Western Medicine Integrated Hospital from September 2016 to August 2019 were collected, including Xpert MTB/RIF and gene chip results. The isolated and cultured strains from patients were subjected to fluorescence PCR melting curve detection. Using Bactec MGIT 960 drug susceptibility results as the reference, the diagnostic efficacy of Xpert MTB/RIF, Fluorescence PCR melting curve and gene chip technology for rifampicin resistance were analyzed, and the receiver operating characteristic curve (ROC) was drawn for comparative analysis.Results:Take Bactec MGIT 960 as the gold standard, the sensitivity of Xpert MTB/RIF, Fluorescence PCR melting curve and gene chip technology for rifampicin resistance were 88.89% (16/18), 94.44% (17/18), 88.89% (16/18) respectively; the specificity were 96.21% (127/132), 96.21% (127/132), 95.45% (126/132), respectively. There was no statistically significant difference in the sensitivity and specificity among the three detection methods ( P>0.05). The Kappa values of the three molecular methods for detecting rifampicin resistance were 0.794, 0.827 and 0.770, respectively. The three detection methods have good diagnostic value for rifampicin resistance ( P<0.01), but there is no statistically significant difference between the three methods ( P>0.05). There were 8 cases of inconsistent results between the three methods and Bactec MGIT 960 drug sensitivity. Conclusion:Xpert MTB/RIF, Fluorescence PCR melting curve and gene chip technology have comparable ability to detect rifampicin resistance, all of these have high sensitivity and specificity for detecting rifampicin resistance and are suitable for rapid screening.