Genetic Diversity of Iranian Mycobacterium bovis Subtypes Analyzed by PCR-RFLP and Spoligotyping

Within the course of this 18-month long work spanning 2010 and 2011, a total of eight human Mycobacterium bovis isolates collected from 1,320 tuberculosis-suspected patients, along with 68 bovine isolates were subjected to PCR-RFLP of pncA gene to assess their resistance to Pyrazynamide. All the isolates were subsequently spoligotyped to better understand their potential epidemiological links. As results showed, only 0.6% of the patients were infected with M. bovis, i.e. a considerably smaller rate compared to previous reports from Iran. Besides, all the isolates proved to be resistant to pyrazynamide. Consulting the SPOLDB4 spoligotyping databank, two patterns, namely ST595 and ST694, were detected among human isolates. Moreover, 12 patterns were found among the bovine isolates. ST595 was the single spoligotype shared between human and bovine hosts. For health officials, these observations indicate that in the Iranian environment M. bovis continues to produce a health risk to human.