Mycobacterium tuberculosis Diversity by Exact Tandem Repeats-Variable Number Tandem Repeat Method in Azerbaijan, Iran
چکیده
Background Tuberculosis (TB) is the leading cause of adult deaths among infectious agents. One of the genetic fingerprinting techniques to study the epidemiology of TB is variable number tandem repeat (VNTR). The purpose of this study was to determine the diversity of Mycobacterium tuberculosis isolated from patients in Azerbaijan, Iran by exact tandem repeats (ETR)-VNTR method. Methods We used the ETR-VNTR method to analyze the genotypes of M. tuberculosis isolates. Forty-seven isolates were collected from pulmonary and extra pulmonary Tuberculosis patients associated with epidemiological data such as human immunodeficiency virus, anti-TB drugs use, cigarette smoking, diabetes mellitus, lung cancer, contact with TB patients, Bacillus Calmette-Guerin vaccine use, cough, housekeeping, fever, and other risk factors from April 2013 to February 2015 in Tabriz Research Center of Tuberculosis and Lung Disease. Three loci ETR-A, ETR-B, and ETR-C of VNTR patterns were studied. The patients' data were checked to determine the relationships between the epidemiological data and M. tuberculosis diversities. Results Among the 47 isolates, 45 separate ETR-VNTR patterns consist of 9 clusters, 24 nonclusters (unique patterns) were found. No locus was observed in 2 samples. Diabetes and close household contacts were identified as important risk factors for TB in our subjects with unique patterns. Conclusions Thirty-three distinct patterns were distinguished. In the case of respiratory symptoms in patients with diabetes and close household contact patients, TB can be considered as the important differential diagnosis with unique patterns.