Abstract: Objective To evaluate rifampin-resistant Mycobacterium tuberculosis by PCR-SSCP technique to detect rpoB gene mutation in Mycobacterium tuberculosis of sputums. Methods Fifty clinical isolates of rifampin-resistant and multidrug resistant Mycobacterium tuberculosis, twelve sensitive strains, Hiirty-five rifampin-resistant strains from sputum specimens of patients with pulmonary tuberculosis, were analyzed by PCR-SSCP technique, with H₃₇Rv reference as control group. Results The characteristics of PCR-SSCP grah in fifty strains of rifampin-resistant were different from H₃₇Rv except for five strains. In comparison with susceptibility testing methods,the sensitivity and specificity were 90% and 100% respectively. Twelve sensitive strains were same as H₃₇Rv. In thirty-five strain from sputum specimens of patients with pulmonary tuberculosis,twenty-one strains of them were positive by PCR. The characteristic of SSCP graph in fifteen of them were different bom H₃₇Rv, and the characteristics of PCR-SSCP graph in twenty-eight of them were different from H₃₇Rv, the positivity was 80%. Ccmdusicm llie PCR-SSCP can easily and rapidly detect rifampin resistance of Mycobacterium tuberculosis,the technigue might be used for rapidly detect Mycobacterium tuberculosis rifampin resistance in clinical specimen directly.

Key words: Mycobacterium tuberculosis , rpoB gene, Polymerase chain reaction, Polymorphism，single-stranded conformation