Study of mycobacterium tuberculosis in patients with pulmonary tuberculosis by drug resistance gene detecting

Objective To investigate drug resistance of mycobacterium tuberculosis,compare detecting effect of two methods and evaluate their value of clinical application.Methods All of the strains of mycoba-cterium tuberculosis were tested for resistance to RFP,INH,SM,PZA and EMB by the absolute concentration method on lowenste in-jensen medium and the mutation of the rpoB,katG,rpsL,pncA and embB resistanc genes in mycobacterium.Tuberculosis was tested by polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP).Results 400 cases of tuberculosis drug resistance in patients with conventional susceptibility test resistance 316 cases (79.8%);resistant strains resistant gene detection 288,the mutation rate(72.0%):the RFP cases of resistance and resistance was significantly higher than that of SM,PZA and the EMB(resistant cases:F=2.45,2.56,2.69,P＜0.05;ResNtance:F=2.55,2.66,2.79,P＜0.05);the mutants and mutation rate of rpoB was higher than that of katG,rpsL,rpoB and embB(mutant:F=2.28,2.46,3.19,3.33,P＜0.05～O.01;mutation rate:F=2.36,2.61,3.25,3.45,P＜0.05～0.01);the gene mutation rate was higher in strains isolated from high concentration resistance than those in strains isolated from low concentration resistance;the more irregular treatment was longer,the rate of drug-resistant was higher(resistance:F=2.77,2.88,P＜0.05;mutation rate:F=2.72,2.85,P＜0.05).Conclusion PCR-SSCP is a sensitive and specific method for rapid detecting rpoB,katG,rpsL,pncA and embB gene mutations of mycobacterium tuberculosis. Key words: Mycobacterium tuberculosis; Drugresistance; Drug resistancegene; Polymerase chain reaction