Abstract:

Objective To evaluate the value of fluorescence PCR melting curve analysis in Mycobacterium tuberculosis (MTB) identification and drug-resistant TB detection.Methods The sputum specimens from 976 suspected TB patients were collected during September 2015 to December 2016 in Chest Hospital of Xinjiang Uyghur Autonomous Region. MTB and its drug resistance to rifampicin and isoniazid were detected by fluorescence PCR melting curve analysis. The results of MGIT 960 liquid culture method and liquid drug resistance test were stipulated as criterion to evaluate the sensitivity, specificity, agreement rate and Kappa value of melting curve analysis in MTB identification and drug-resistant TB detection.Results The sensitivity, specificity, Kappa value and diagnostic coincidence rate of the melting curve analysis for MTB DNA identification were 85.44% (135/158), 94.01% (769/818), 0.75 and 92.62% (904/976), respectively, taking the result of MGIT 960 liquid culture as gold standard. Taking MGIT 960 liquid drug resistance test as gold standard, the sensitivity, specificity, Kappa value and diagnostic coincidence rate of the melting curve analysis for isoniazid-resistant mutation detection were 83.33% (20/24), 94.59% (105/111), 0.76 and 92.59% (125/135), respectively. Meanwhile, the sensitivity, specificity, Kappa value and diagnostic coincidence rate of the melting curve analysis for rifampin-resistant mutation detection were 95.83% (23/24), 95.50% (106/111), 0.86 and 95.56% (129/135), respectively.Conclusion The probe based melting curve analysis can detect rifampicin-resistant and isoniazid-resistant mutation rapidly and accurately, which can be used for the rapid detection of the multi-drug resistant mutations of MTB.

Key words: Tuberculosis, mutidrug-resistant, Fluroimmunoassay, Molecular probe techniques, DNA mutationcel analysis, Rifampin, Isoniazid