DNA fingerprinting of Mycobacterium tuberculosis isolates of pulmonary tuberculosis patients in Markazi province by PGRS-RFLP method

Background: Tuberculosis is an old problem that is currently considered a great challenge. Noticing Iran’s borders with Afghanistan and Pakistan, which are among the 22 high burden countries around the world, the present study was conducted to analyze the current molecular epidemiology of TB and survey genetic diversity of Mycobacterium tuberculosis strains in Markazi province, Iran. Materials and Methods: In this experimental study, 57 sputum specimens from smear positive patients admitted to health centers in Markazi province were cultured on specific mycobacterial culture media. Genomic DNA was extracted by standard protocols of WHO and digested separately by PvuII and AluI. Electrophoresis was performed and DNA fragments were transferred to positively charged nylon membrane by southern blotting method and hybridization by PGRS probe. The hybridized strains were subsequently detected by enzymatic reaction and analyzed. Results: Genotyping of the isolates by PGRS-RFLP with Pvu II and AluI displayed a wide range of genetic diversity so that 50 and 45 genotypes were identified, respectively. Conclusion: Noticing the great diversity of PGRS in the Mycobacterium tuberculosis strains, it can be concluded that in the study population, the majority of the patients hadtuberculosis with different etiologies. Therefore, it seems that reactivation of latent infection has had the main role in the spread of tuberculosis.