Phylogenetic analysis of Mycobacterium avium subspecies paratuberculosis isolated from dairy cattle of Tehran province

Paratuberculosis or Johne's disease is a severe chronic and progressive intestinal inflammation in ruminants caused by Mycobacterium avium subspecies paratuberculosis which can lead to great economic losses to the livestock industry especially dairy idustry. On the other hand, it is known as a zoonosis in the pathogenesis of Crohn's disease in humans. This study was conducted with the purpose of phylogenetic analysis of Mycobacterium avium par tuberculosis isolated from dairies in Tehran. In this study, DNA extraction was performed on 100 stool samples from Johne's disease infected cattle. Then using specific primers of gene IS900, Nested PCR reactions was carried out and from the positive samples isolated, 14 cases were randomly selected and sent to Macro gene Company in Korea for sequencing. In this study, 28 samples from a total of 100 stool samples were positive for MAP. After sequencing, more than 99% of the positive samples were similar with sequences in gene bank. The Results showed that Nested PCR technique can be a valuable test for detection of Mycobacterium avium paratuberculosis in animals. The sequencing results indicated that strains KJ629114 and AE016958 had the highest similarity and CP000325 had the highest difference in GyrA gene. In regard to GyrB gene, the highest similarity belongs to strains AE016985, CP005928 and CP009614 and the highest difference was related to GU143884