Abstract:

Objective To detect rifampicin, isoniazid, ethambutol, streptomycin and fluoroquinolone drug resistance mutations in Mycobacterium tuberculosis using the fluorescent PCR probe melting curve method, and evaluate its potential for clinical application. Methods A total of 153 Mycobacterium tuberculosis clinical isolates from outpatients of the Fourth People’s Hospital of Fushun were collected from January 2018 to August 2018. Drug susceptibility testing was performed using the proportional method to evaluate the sensitivity, specificity and diagnostic consistency rate of the fluorescent PCR probe melting curve method. Results The sensitivity, specificity, diagnostic consistency rate and Kappa value of the fluorescent PCR probe melting curve method for detection of drug resistance mutations to rifampicin was 95.56%(43/45), 94.44% (102/108), 94.77% (145/153) and 0.88, respectively, while that for detection of drug resistance mutations to isoniazid was 90.57%(48/53), 96.00% (96/100), 94.12% (144/153) and 0.87, respectively, and 85.71%(18/21), 92.42% (122/132), 91.50% (140/153) and 0.69, respectively, for detection of drug resistance mutations to ethambutol. The sensitivity, specificity, diagnostic consistency rate and Kappa value for detection of drug resistance mutations to streptomycin was 89.66% (26/29), 92.74% (115/124), 92.16% (141/153) and 0.76, respectively, and that for detection of fluoroquinolone resistance mutations was 93.75%(15/16), 96.35% (132/137), 96.73%(147/153) and 0.81, respectively. Conclusion The fluorescent PCR probe melting curve method has good sensitivity and specificity for the detection of resistance mutations to rifampin, isoniazid, ethambutol, streptomycin and fluoroquinolone, and can thus be used as a clinical detection method for resistance mutations to the five most important anti-MTB drugs, providing important evidence for doctors when making decisions on which drug combinations to use in treatment regimens.

Key words: Tuberculosis,multidrug-resistant, Polymerase chain reaction, Molecular probe techniques, Microbial sensitivity tests, Evaluation studies