بررسی تشخیص سریع گونه مایکوباکتریوم بویس با استفاده از روش ‭PCR-RFLP‬

As many as two billion humans and fifty million bovins in the world are estimated to bear infection with Mycobcaterium tuberculosis complex bacteria that comprises M.tuberculosis, M. africanum, M bovis, M. bovis BCG, M. microti, M, canetii, M. caprae, and M. pinnipedi. These closely related pathogens with their typically long incubation time are extremely cumbersome in isolation and identification. Similar to rest of the world, M. tuberculosis and M. bovis cause majority of human and bovine tuberculosis cases in Iran. Thus, a principle objective of this study was assessment of a methodology able to differentiate M. tuberculosis from M. bovis. A PCR- RFLP technique was selected operating on a 548 bp stretch of the Oxy R pseudo gene. The nucleotide 285 of this fragment from M. bovis and M. bovis BCG comprises an Adenine that is replaced with Guanine in rest of the M. tuberculosis complex bcteria leading to inactivation of an AluI restriction site. Consequently, compared to other M. tuberculosis complex mycobacteria with 3 restriction sites (AGCT) for AluI, M. bovis and M. bovis BCG carry four positions in this genomic segment. Ninety mycobacterial isolates collected from human, cattle, buffalo and pigeons plus six laboratory strains of M. bovis BCG 1173P2, M. bovis AN5, M. tuberculosis C, PN, DT and Mycobacterium avium D4 were tested by this system and subsequently all M. bovis and M. bovis BCG isolates were successfully identified. The Oxy R RFLP- PCR method is simple and suitable for mycobacteriology laboratories.