Genotyping of Mycobacterium Tuberculosis Isolated from Suspected Patients in Tehran in 2015-2017

Unlike many global efforts to eradicate tuberculosis caused by Mycobacterium, it remains as a life-threatening infection with a worldwide incidence of 1.5 million cases each year. However, due to the lack of information about Mycobacterium tuberculosis characterization, more studies are required to evaluate strain diversity and epidemiology of tuberculosis to improve the therapeutic approaches. This study aimed to genotype the Mycobacterium tuberculosis isolated from suspected patients in Tehran, Iran through 2015-2017. In the current study, 30 isolates (sputum, broncho-alveolar lavage and biopsy) were collected from different tuberculosis patients at Massoud Clinical Lab of Tehran from 2015 to 2017. To find the single nucleotide polymorphisms and mutated regions, polymerase chain reaction (PCR) was performed on all the isolates to amplify the katG and gyrA genes. Then, PCR products were sequenced and analyzed. The majority of isolates were assigned to PGG2 (90%), followed by PGG3 (10%) but no isolate belonging to PGG1 was found. Our findings demonstrate a remarkable epidemiological pattern of tuberculosis in Tehran. In group 2, isolates showed a considerably higher frequency compared to isolates in group 3, which is consistent with other findings reported in Iran. However, in contrast to other Iranian studies, no isolated strains were categorized in principal PGG1.