Abstract: Objective To investigate the relationship between the therapeutic effect and the mutations of the drug-resistant genes in multi-drug resistant pulmonary tuberculosis, and to provide the theoretical evidence for treating the multi-drug resistant pulmonary tuberculosis. Methods108 M. tuberculosis clinical isolates from sputum specimens were detected by PCR-SSCP and the traditional drug susceptibility testing. The therapeutic effect of the patients with multi-drug resistant tuberculosis was evaluated. ResultsThe rates of mutations of katG gene for Isoniazid resistance, rpoB gene for Rifampin resistance, rpsL gene for Streptomycin resistance, pncA gene for Pyrizinaride resistance and embB gene for Ethambutol resistance were 70.4%, 72.2%, 71.9%, 53.4% and 31.7%, respectively. The rate of gene mutation was higher in the isolate with high concentration of drug resistance than that with low concentration of drug resistance. According to the Results of PCR-SSCP and drug susceptibility testing, the patients were treated with 1 to 2 kinds of anti-TB drugs never used before combined with a regimen of KAOP (kanamycin, ofloxacin, sodium aminosalicylate) for average 1.4 years. The sputum bacterial negative conversion rate was 74.1%, the sputum culture-negative conversion rate was 67.5%, the absorption rate of lesion was 83.3%, 65.3% of the cavities closed up. There wasn’t any serious side effect to be found. ConclusionThe detection of drug-resistant genes might be helpful for the clinical treatment of multi-drug resistant pulmonary tuberculosis.

Key words: Multi-drug resistance, M.toberculosis, PCR-SSCP,gene mutation, therapy