Diagnostic value of multicolor probe melting curve analysis for drug resistance to six antituberculosis drugs

Zhang Yunting; Hao Yuepeng; Feng Jianchun; Jia Dijing; Ma Weili

doi:10.3760/j.issn.1673-4777.2026.07.011

Abstract：Objective To investigate the diagnostic efficacy of multicolor probe melting curve analysis(MMCA)for drug resistance to six antituberculosis drugs,and to explore the influencing factors and predictive value of multidrug-resistant pulmonary tuberculosis(MDR-TB).Methods A total of 1 724 patients suspected to be tuberculosis who were hospitalized and treated in Hebei Chest Hospital from January 2024 to March 2025 were enrolled as study subjects.Early morning sputum samples were collected for Mycobacterium tuberculosis(MTB)culture,and 574 samples were identified as MTB-positive by mycobacteria growth indicator tube 960 system(MGIT960)rapid liquid MTB culture system.MMCA and MGIT960 rapid liquid MTB culture were used to detect drug resistance to six antituberculosis drugs including rifampicin,isoniazid,ethambutol,streptomycin,levofloxacin and moxifloxacin,respectively,and the diagnostic efficacy of MMCA for the six drugs was analyzed.Patients were divided into MDR-TB group and non-MDR-TB group according to the diagnostic results.Clinical data were compared between the two groups.Multivariate Logistic regression model was used to analyze the influencing factors of MDR-TB,and receiver operating characteristic(ROC)curve was used to evaluate the predictive efficacy of the model.Results Taking MGIT960 rapid liquid MTB culture as the gold standard for drug resistance diagnosis,the sensitivities of MMCA for detecting rifampicin,isoniazid,ethambutol,streptomycin,levofloxacin and moxifloxacin were 95.24％,94.87％,92.75％,96.97％,92.42％and 89.47％,respectively;the specificities were 98.52％,97.37％,98.02％,98.74％,97.64％and 95.74％,respectively;and the Kappa values of consistency analysis were 0.941,0.917,0.880,0.946,0.861 and 0.758,respectively.A total of 136 patients were diagnosed with MDR-TB and 438 with non-MDR-TB by MGIT960 rapid liquid MTB culture.Multivariate Logistic regression analysis showed that residence,treatment history,tuberculosis contact history and tuberculous cavity were independent risk factors for MDR-TB.A regression equation was established based on these factors,and the area under the curve of the model for predicting MDR-TB was 0.843(95％confidence interval:0.805-0.882),with a sensitivity of 66.20％and a specificity of 87.00％.Conclusion MMCA shows favorable diagnostic efficacy in detecting drug resistance to rifampicin,isoniazid,ethambutol,streptomycin,levofloxacin and moxifloxacin,and is easy to operate,facilitating rapid screening of MDR-TB.The coexistence of rural residence,retreatment,tuberculosis contact history and tuberculous cavity strongly suggests MDR-TB.