Abstract: Objective To detect 16Sr RNA+DNA and 23S DNA in clinical samples of Mycobacterium tuberculosis simultaneously in the same system by fluorescence quantitative PCR, and detect tuberculosis DNA in samples by other tuberculosis DNA-PCR reagents, as well as culture Mycobacterium tuberculosis. And to explore its different clinical significance. Methods Multicenter double-blinded fluorescence quantitative polymerase chain reaction (16Sr RNA+DNA/23S DNA) was used to detect sputum samples from patients with tuberculosis in three hospitals. Chi-square test and t-test were used for statistical analysis.Results The coincidence rate of 16Sr RNA+DNA/23S DNA detection reagent and tuberculosis DNA-PCR contrast reagent was 95.76%, of which the positive coincidence rate was 95.08%, and the negative coincidence rate was 96.1%. Comparing to the culture of tuberculosis bacteria, the positive coincidence rate was 81.35%, the negative coincidence rate was 87.90%, the total consistent rate was 85.92%, and the coincidence rate was 86%. There were 87 samples detected positive by our kit and sputum culture negative in this study, of which 71 were detected positive by KaiJie Kit and negative in sputum culture samples.There were 58 samples with positive sputum culture test and negative detected by our kit ,of which 52 were negative detected by KaiJie Kit. In this study, the differences of CT values between 23S DNA and 16Sr RNA+DNA of 75 positive and 34 negative sputum cultures samples were analyzed (the CT value was over 30), P<0.01. The differences were statistically significant. Conclusion 16Sr RNA + DNA detection is more sensitive than Mycobacterium tuberculosis DNA detection. 16Sr RNA+DNA/23S DNA tests has a certain role in judging the bacterial activity of Mycobacterium tuberculosis infection which is a great tool to evaluate the efficacy and infectivity of Mycobacterium tuberculosis patients.

Key words: Mycobacterium tuberculosis complex, Polymerase chain reaction assay, Therapeutic efficacy monitoring