Isolation, Molecular Identification And Genomic Pattern of‌ ‌Mycobacterium Bovis Isolates Collected From Tuberculin-Positive Cattle‌ ‌in Infected Farms of Shiraz

Background: Mycobacterium bovis is the main cause of tuberculosis in cattle. At the global scale and also in Iran, the most frequent currently-in-use method in the detection of infected cattle is tuberculination. Objective: The present study was aimed to improve our genomic knowledge of Mycobacterium bovis population structure in cattle farms of Shiraz. Materials and Methods: Fifty pathological samples from tuberculin-positive cattle collected from two slaughterhouses at Shiraz were subjected to bacterial culture on glycerinated and pyruvated Lowenstein-Jensen media. Genomic material from culture-positive slopes was extracted and used in PCR-16S rRNA, PCR-IS6110, and PCR-RD typing experiments. All the M. bovis isolates were further genotyped using pvu II-digested PGRS-RFLP strategy. Results: In bacterial culture, a total of 13 (26%) samples proved to carry live mycobacteria where in PCRs their identity was all shown to be M. bovis. Genotype profiling by RFLP-PGRS displayed two patterns with 10 isolates shared a single profile identical to that of M. bovis BCG (1173 P2) strain and three holding a different genotype. Conclusion: While higher frequency of a BCG-like M. bovis in cattle farms of Shiraz is not surprising as this is a typical characteristic of Iranian M. bovis population, we assumer detection of a highly similar strain found in our work might indicate local evolution of new M. bovis strains in the region or infiltration of such strain(s) through cattle farming activities.