Mutations of KatG gene and isoniazid-resistant Mycobacterium tuberculosis isolates from Xinjiang

Objective To explore the relationship between isoniazid(INH) resistance and KatG gene mutation in Mycobacterium tuberculosis.Methods Totally 238 sputum samples were collected from tuberculosis patients in Xinjiang and 60 Mycobacterium tuberculosis strains were isolated from the samples(28 drug susecptible strains,32 strains of inonizaid-resistance or multidrug resistance including inoniazid).Genomic DNA was extracted form Mycobacterium tuberculosis isolates and standard strain H3TRV.The KatG gene was amplified with PCR and KatG gene mutation was detected with single strand conformation polymorphism(SSCP) and sequencing.Results The results of PCR-SSCP of 28 susceptive strains were the same with that of H37RV.KatG gene was amplified from 32 drug-resistance strains successfully.There were 11 cases had single point mutation in KatG gene with a mutation rate of 34.37%.Conclusion The INH resistance rate of Mycolacterium tuberculosis strains isolated from Xinjiang is among the highest in China.The KatG gene mutation is involved in INH-rsistance of Mycobacterium tubeculosis.