Evaluation of the prevalence of Mycobacterium tuberculosis strains isolated from tuberculosis patients referred to Pasteur Institute of Iran

Tuberculosis is a threat to public health. The epidemiology of tuberculosis can be effective in identifying the source of infection, the dominant circulating strains and achieving transmission pathways in the world. The aim of this study was to determine the genotype of Mycobacterium tuberculosis (M. tb) strains in patients referred to Pasteur Institute of Iran between 2018 and 2019.

In this study, 50 confirmed M. tb strains were evaluated. After M. tb strains identification and determining the drug susceptibility test, all strains were genotyped by MIRU-VNTR (Mycobacterial Interspersed Repetitive Unit Variable Number Tandem Repeat) method.

The most frequent genotype in all strains was CAS/Delhi (42%), followed by Haarlem (24%), NEW-1 (10%), LAM (8%), Beijing (8%), Cameroon (4%), EAI (% 2) and S (2%). Three clonal complexes and 44 singleton isolates were identified. Beijing genotype was the common genotype in MDR-TB strains. Also, QUB26 and QUB4156 loci had shown the highest of discriminative and allelic diversity.

CAS/Delhi and Beijing genotypes were introduced as the dominant genotypes in drug sensitive and MDR strains, respectively.