Evaluation of Molecular Diversity of Mycobacterium tuberculosis Strains By Polymorphisms in RD Regions

Abstract

Background: The region of differences (RDs) polymorphisms is a potential molecular epidemiology method to distinguish origins of Mycobacterium tuberculosis (MTB). Till date, 68 RDs were identified in MTB. This study was designed to investigate highly polymorphic regions (RD1, RD150 and RD181) among MTB strains isolates from Iranian Pulmonary tuberculosis patients (PTB). Method and materials: A total of the 190 MTB isolates were identified by conventional and molecular methods. Thereafter, Spoligotyping and RD typing (RD1, RD150 and RD181) were applied to genotype these strains. Results: The most frequent spoligotype belong to Haarlem (n=72, 37.8%) followed by CAS (n=37, 19.4%), T1 (n=18, 9.4%) and Beijing (n=11, 5.7%) lineages. Deletion in RD181 was only identified among Beijing lineage. Conclusion: Deletion in RD181 was prominent among the prevalent Beijing strains in Iran. In this regard, this deletion marker can be used in identification, phylogeny, and molecular epidemiology of the Beijing genotype.