Genotyping of Mycobacterium tuberculosis Strains in Eastern and Western Azerbaijan provinces

Background: Years after the development of antituberculosis (TB) drugs, many people continue to suffer from this disease. To control the spread of TB, strains of the Mycobacterium tuberculosis complex need to be determined, and sources of infection must be identified. Such steps should help to prevent transmission of the infection. Objectives: The aim of the present study was to perform molecular genotyping of isolates of the M. tuberculosis complex to obtain a better understanding of the disease and aid appropriate disease-prevention decision making in northwestern Iran, thereby reducing the burden of TB. Methods: One hundred ninety-four culture-positive M. tuberculosis isolates obtained from patients in northwestern Iran were analyzed using the mycobacterial interspersed repetitive unit-exact tandem repeats (MIRU-ETR) method. Results: The MIRU-ETR method distinguished 162 different patterns in the 194 isolates, comprising 23 clusters and 139 unique patterns. Its discriminatory power according to the Hunter-Gaston discriminatory index (HGDI) was 0.9978. The largest cluster contained six isolates. The rate of clustering among Mycobacterium strains was 28.35%, indicating that the majority of TB cases in this region of Iran were due to reactivation rather than recent transmission. Conclusion: This research indicated that various strains of M. tuberculosis were responsible for TB and that the majority of cases were due to reactivation. Given the discriminatory power of the MIRU-VNTR method (0.9978), it is suitable for detecting the disease once sufficient numbers of cases are available for evaluation. Thus, it can be employed as a first-line method in genotyping of TB strains in Iran.

کلیدواژه ها:

Tuberculosis ، Molecular Diversity ، Iran ، ETR