ABSTRACT
@#Abstract: Objective To explore and analyze the diagnostic value of multicolor melting curve analysis (MMCA) for the resistance of five anti-tuberculosis drugs, so as to clarify the clinical value of MMCA in detecting drug resistance of Mycobacterium tuberculosis. Methods From April 2021 to May 2022, 200 patients with positive Mycobacterium tuberculosis admitted to the Fourth People's Hospital of Qinghai Province were selected as research objects, and sputum specimens were taken from the patients. Traditional Mycobacterium tuberculosis drug sensitivity test (modified Löwenstein-Jensen medium method) and MMCA analysis were respectively given to detect the resistance of five anti-tuberculosis drugs, including isoniazid, ethambutol, streptomycin, rifampicin and isoniazid, respectively. Those samples with inconsistent results between the two diagnosis methods were subjected to gene sequencing verification, and the diagnosis efficiency of MMCA for the five anti-tuberculosis drugs was compared. Results Using Mycobacterium tuberculosis drug sensitivity as the gold standard for drug resistance diagnosis, the sensitivity of MMCA for detecting drug resistance of rifampicin, ethambutol, streptomycin, isoniazid and levofloxacin were 95.83% (46/48), 93.75% (15/16), 100.00% (15/15), 100.00% (20/20) and 70.00% (7/10), respectively, with statistical differences between groups (P<0.05). There were no statistically significant differences in the specificity, positive predictive value, negative predictive value and accuracy of MMCA for the five anti-tuberculosis drugs (P>0.05). For the 8 samples with inconsistent results between MMCA and modified Löwenstein-Jensen medium method, gene sequencing was performed and compared with the results of gene sequencing. After comparison with gene sequencing results, it was found that the coincidence rate of MMCA and gene sequencing results was 75.00% (6/8). Conclusions In the detection of drug-resistant mutations in TB patients, multi-color probe fusion curve analysis has high diagnostic efficacy for first-line anti-tuberculosis drugs, but is not sensitive to second-line anti-tuberculosis drug levofloxacin. Therefore, for the detection of first-line anti-tuberculosis drugs, MMCA has a good clinical application prospect.