Abstract:

Objective To analyze the value of GeneXpert MTB/RIF (GeneXpert), gene chip and MeltPro TB in the detection of drug resistance of Mycobacterium tuberculosis (MTB). Methods A total of 774 cases of pulmonary TB with positive culture of MTB in sputum from January 2017 to January 2018 in Xi’an Chest Hospital were retrospectively analyzed. The results of phenotypic drug sensitivity test, GeneXpert detection, gene chip detection and MeltPro TB detection were collected. Based on phenotypic drug susceptibility criteria, the efficacy of the three molecular biology methods to detect drug resistance of MTB was analyzed. The accuracy of the three molecular biology methods to detect rifampicin (RFP) resistance was compared according to the area under receiver operating characteristic (ROC) curve. Results With phenotypic drug susceptibility as standard, the sensitivity and specificity were 95.6% (87/91) and 93.6% (249/266) for GeneXpert in detecting RFP resistance; and for gene chip in detecting RFP and isoniazid (INH) resistance, the sensitivity were 92.8% (90/97) and 78.8% (130/165), and the specificity were 96.8% (610/630) and 99.1% (557/562). For MeltPro TB in detecting RFP, INH, levofloxacin (Lfx) and amikacin (Am), the sensitivity were 94.4% (51/54), 82.4% (61/74), 87.1% (27/31) and 75.0% (6/8), and the specificity were 93.9% (138/147), 95.3% (121/127), 98.8% (164/166) and 99.5% (188/189). The area under the ROC curve of GeneXpert in detecting RFP resistance was 0.95±0.02; the area under the ROC curve of gene chip and MeltPro TB in detecting RFP resistance were 0.93±0.03. Conclusion Detection of MTB resistance to the first-line anti-tuberculosis drugs by GeneXpert, gene chip and MeltPro TB was reliable, and detection of MTB resistance to Lfx and Am by MeltPro TB was reliable.

Key words: Tuberculosis, multidrug-resistant, Microbial sensitivity tests, Molecular probe techniques, Nucleic acid amplification techniques, Evaluation studies