Abstract:

Objective To evaluate the value of fluorescent PCR probe melting curve analysis (MeltProTB) in detecting the resistance of Mycobacterium tuberculosis complex to rifampicin (RFP) and isoniazid (INH).Methods Eight hundred and eighty-three pulmonary tuberculosis patients with multidrug-resistant tuberculosis (MDR-TB) admitted in Heze City Infectious Diseases Hospital in Shandong Province were enrolled during January 2015 to July 2018. Two hundred and fifteen patients with sputum smear positive were selected for further culture. Two hundred strains identified as Mycobacterium tuberculosis complex (MTBC) were tested for drug resistance to RFP and INH by proportional drug susceptibility testing (DST) and MeltPro TB method. The sensitivity, specificity, coincidence rate and consistency (Kappa test) of resistance to RFP and INH detected by MeltPro TB were analyzed using DST results as gold standard.Results Of the 200 MTBC isolates, the sensitivity, specificity and coincidence rate of RFP resistance were 96.4% (106/110; 95%CI: 90.7%-98.9%), 80.0% (72/90; 95%CI: 70.5%-87.1%) and 89.0%(178/200) by MeltPro TB based on DST as the standard. The sensitivity, specificity and coincidence rate of RFP resistance were 85.4% (123/144; 95%CI: 78.6%-90.7%), 96.4% (54/56; 95%CI: 87.7%-99.6%) and 88.5% (177/200) by MeltPro TB based on DST as the standard. The Kappa value of MeltPro TB and DST for RFP resistance in MTBC was 0.78, and was 0.74 for INH resistance in MTBC.Conclusion MeltPro TB has high sensitivity and specificity in detecting drug resistance of MTBC to RFP and INH, and it has good consistent with DST in detecting MTBC resistance to RFP and INH, which is helpful for early detection and treatment in patients with drug-resistant tuberculosis.

Key words: Mycobacterium tuberculosis, Polymerase chain reaction, Molecular probe techniques, Rifampin, Isoniazid, Microbial sensitivity tests, Data interpretation, statistical