Clinical study on fluoroquinolones resistance of Mycobacterium tuberculosis detected by fluorescence PCR melting curve method
Objective To evaluate the efficiency of fluorescent PCR melting curve method in early diag-nosis of fluoroquinolones (FQs) resistance in the patients with tuberculosis,and to analyze the situation and characteristics of FQs resistance,so as to provide a basis for the standardized diagnosis and treatment of rifam-picin resistance/multidrug resistant tuberculosis (RR/MDR-TB) and pre-extensively drug resistant tuberculo-sis (pre-XDR-TB).Methods A total of 1094 smear positive samples from the outpatients and inpatients of Guiyang Municipal Public Health Treatment Center from January 2021 to August 2022 were collected and conducted the Roche solid culture method and bacterial species identification.Finally,589 cases of tuberculosis conducted the phenotypic drug sensitivity test and fluorescent PCR melting curve method for detecting rifam-picin (RFP),isoniazid(INH),ethambutol(EMB) and FQs resistance.The phenotypic drug sensitivity test served as the standard to evaluated the diagnostic efficiency of the fluorescent PCR melting curve method;the relationship between the patients' FQs resistance and clinical characteristics was analyzed according to the phenotypic drug sensitivity results.Results The sensitivity,specificity,coincidence rate and Kappa value of fluorescence PCR melting curve method for detecting FQs drug resistance were 91.30%,97.69%,96.94% and 0.86 respectively;the area under the curve (AUC) was 0.945,which was higher than 0.924,0.923 and 0.850 of RFP,INH and EMB.The drug resistance rate of FQs in the patients with RR/MDR-TB was 22.80%,the Kappa value of fluorescence PCR melting curve method for detecting the patients' FQs drug re-sistance was 0.83,the consistency was good,AUC was 0.936.There was no statistically significant difference in sensitivity,specificity and coincidence rate of FQs resistance in TB patients with different bacterial loads by fluorescence PCR fusion curve (P>0.05).The treatment type,history of anti-tuberculosis,pulmonary cavity and MDR-TB were related with FQs resistance (P<0.05).Conclusion The fluorescent PCR melting curve method has good diagnostic efficiency for FQs resistance in the patients with tuberculosis.
mycobacterium tuberculosisdrug resistancefluorescence PCR melting curve methodfluoroquinolonespre-extensively drug resistant tuberculosis