Search

Mycobacterium tuberculosis, the etiologic agent of tuberculosis, causes large-scale morbidity and mortality, particularly in developing countries. In recent years, there has been a significant increase in the drug-resistant ability of M. tuberculosis, triggering a major public health crisis. A detailed analysis of the evolution of the mycobacterial genome helps to better understand the genotype–phenotype relationship in this bacterium. Different strain typing methods have already revealed the worldwide diversity of mycobacterial isolates. Therefore, DNA-fingerprinting tools have been developed to improve tuberculosis case detection and control. Molecular typing techniques allow to detect and follow the spread of individual strains of the M. tuberculosiscomplex (MTC), complementing conventional epidemiological methods. Among these techniques, restriction fragment length polymorphism (RFLP) has been considered the standard method for genotyping of MTC. The aim of this work was to isolate M. tuberculosisfrom rodents in cattle farms contaminated with MTC located in the city of Booin-Zahra, Iran.

Tuberculosis (TB) is one of the most common zoonotic infectious diseases in the world. Identification of Mycobacteriumisolates is essential for proper treatment of TB. The aim of this study was to identify Mycobacteriumisolates collected from TB patients in Alborz Province, Iran, by region of differentiation (RD)-typing. Fifty samples from tuberculosis patients were cultured in pyruvate and glycerinated Lowenstein–Jensen medium. DNA was extracted from the isolates by the van Solingen method and subjected to polymerase chain reaction (PCR)-16SrRNA, PCR-IS6110, and RD-typing with primers RD1, RD4, RD9, and RD12, respectively. Out of 50 isolates, only one isolate appeared negative in IS6110-PCR and was considered nontuberculosis complex. The remaining isolates gave PCR products of approximately 543bp, 245bp, 146bp, 172bp, 235bp, and 369bp with 16s-rRNA, IS6110-PCR, RD-1, RD-4, RD-9, and RD-12 PCR, respectively. PCR-restriction fragment length polymorphism of oxyRpseudogene confirmed the results. All isolates except one from Alborz Province appeared positive for Mycobacterium tuberculosis. Based on the obtained results, all isolates except one were identified as M. tuberculosis. The only negative isolate appeared 93% and 97% similar to Nocardiaor Mycobacterium sp.(Mycobacterium neoaurum), respectively, based on sequencing and alignment of 16s-rRNA and hsp65. Accurate identification of Mycobacteriumisolates is of utmost importance for proper and immediate treatment of TB patients. In this study, RD-typing appeared to be a suitable method for correct identification of M. tuberculosisisolates.