Detection of Isoniazid and Rifampin Resistant Strain of Mycobacterium Tuberculosis Isolated from patients in Golestan province (North of Iran)

Abstract Background and objectives: With almost nine million new cases each year, tuberculosis is still one of the most Life-threatening diseases in the World. Distribution of drug resistant strains of M.tuberculosis has a lot of importance. This research was carried out to determine the frequency of drug resistance of M. tuberculosis in strains isolated in Golestan province. Material and Methods: In this cross -sectional study, 104 isolate of M.tuberculosis which isolated from patients referred to Gorgan tuberculosis Health Center, in 2008 were studied. DNA was extracted by Boiling Method. By using PCR method, we determine the M.tubeculosis strain and resistance to Rifampin (Using IS6110 and Gene rpoB primers) and resistance to Isoniazid (Using InhA and KatG primers). As a Gold Standandard, “Proportional method” was performed for 45 Samples. Results: 87 strains were identified as M.tuberculosis. 6.9% of them were resistant to Isoniazid, 4.6% to Rifampin and 2.3% to both (MDR).Sensitivity and Specifity of PCR method in detection of resistant to Isoniazid were 95.3% and 57.1% and for Rifampin were 94.7% and 33.3%. Conclusion: We found that in our region, the MDR is not very common. More than 16% of isolated strains from tuberculosis suspected patients were MOTT, for this reason it is necessary to mention that use biochemical or PCR method to determine M.tuberculosis is necessary. Key words: Mycobacterium tuberculosis, MDR, PCR, Proportional method , Golestan province.