Abstract

       Background and Objective: Paratuberculosis is a chronic granulomatous enteritis of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). this study aimed to characterize the genome of the MAP 316F strain.

      Methods: The MAP 316F strain was subjected to the PCR-F57 and PCR-IS900 experiments in order to ensure its identity as MAP. This was followed by application of the Thibault genotyping system consisting of eight loci including 292, x3, 25, 47, 3, 7, 10 and 32. Required genomic material for all experiments was prepared using the simple method of boiling. Gel electrophoresis findings related to the typing PCRs were backed by sequencing of amplification products.

      Results: In PCR amplification, eight products with the size of 300, 298, 350, 217, 208, 203, 803 and 649 bp were detected at 292, X3, 25, 47, 3, 7, 10 and 32 loci, holding 3, 2, 3, 3, 2, 2, 2 and 8 copies of TRs at these loci, respectively.

      Conclusion: This genomic pattern is matched with that of the MAP 316F vaccine strain from the French Merial company and also the MAP K10 fully-sequenced strain.

       Keywords: Mycobacterium avium subsp. paratuberculosis, Genomics, Genotyping techniques, Strain

Abstract

        Background and Objective: Paratuberculosis has been repeatedly reported from Iranian ruminant herds. The extrem fastidious nature of Mycobacterium avium subspecies paratuberculsos hinders genomic diversity studies of the pathogen. Short Sequence Repeat analysis is one of the genome-based approches recently developed to overcome this difficulty. In this study we describe the application of SSR genotyping on three Iranian MAP type strains plus the III & V vaccinal strain.

        Methods: All the bacteria were examined by PCR-F57 and PCR-IS900 experiments in order to authenticate their identity as MAP. SSR genotyping using SSR1 & SSR2 loci was conducted according to the Amonsin method. PCR amplicons were sequenced to guarantee the accuracy of findings.

        Results: At SSR1 locus two allels were identified, a larger allel of 770 bp and a smaller allel of 763 bp long. At SSR2 only a single allele, 800 bp long, was detected. Two Iranian bovine and ovine MAP isolates along with the vaccinal III & V strain shared a single SSR1/SSR2 pattern while a different SSR1/SSR2 was represented by the third (caprine) Iranian MAP isolate.

        Conclusion: While finding a shared SSR type between the two Iranian MAP isolates and the III & V strain might represent a mutual ancestral background but this has to be assessed through further studies. Detection of two SSR genotypes between three Iranian type strains is likely a reflection of more MAP clones in Iran.

       Keywords: Mycobacterium avium subspecies paratuberculosis (MAP), SSR genotyping, Genetic marker, Genetic locus