Detecting katG Drug Resistant Genetic Mutation among pneumoconiosis patients complicated with tuberculosis in Mycobacterium tuberculosis L-forms by PCR-SSCP

Objective：To study the relationship between mutation in the katG gene and drug resistance of INH in Mycobacterium tuberculosis L-forms among patients of pneumoconiosis complicated with pulmonary tuberculosis, and to explore the clinical application of PCR-SSCP. Methods： A total of 52 clinical isolated strains of Mycobacterium tuberculosis L-forms were collected. Mutation in the katG genes was detected by PCR-SSCP and traditional antimicrobial susceptibility test （AST）. Results： The results by AST showed that there were 40 persisters in 52 clinical isolated strains. The drug resistant rate was 76.92%（40/52）, and the gene mutation rate of katG was 57.70%（30/52）by PCR-SSCP, the difference was no quite significance （X^2 = 2.8507, P 〉 0.05）. The coincidence rate of two methods was 75.00% （30/40）. Conclusion： The detectionrate of katG resistant strains in Mycobacterium tuberculosis L-forms was high by PCR-SSCP. The combined application of PCR-SSCP and traditional antimicrobial susceptibility test can improve the detecting rate.