Homogeneity of Mycoplasma agalctiae vaccine strains in an agalaxy- high-burden environment

Abstract

Background and Objectives: Interrogation of the genomic relations between Iranian Mycoplasma agalactiae vaccine strains of Taliqan, Lorestan and Shiraz.

Materials and Methods: Two MLVA (covering VNTR loci of 5, 9, 17 and 19) and MLST (comprising dnaA, gltX, gyrB, C,

tufA genes) genotyping systems plus nucleotide structure analysis of P80 gene, was conducted.

Results: The shared MLVA pattern represented by the three strains differed to that of the Mag PG2 laboratory strain, only at locus VNTR19 where the PG2 genome hold a 3 bp longer stretch. In MLST analysis, at dnaA, gltX, gyrB, metS and tufA loci, the three strains displayed alleles 1, 21, 2, 2 and 1, respectively. At, gltX locus a new allele (21) was detected where a new sequence type (ST33) was identified. Besides, the trio strains hold an identical nucleotide structure in their ma-mp81 gene. Conclusion: In explanation, lack of efficient disease control measures, has possibly contributed in evolution of a clone or a few clones that gradually overwhelmed the population over the time. Besides, the similarity between the Iranian and the PG2 strains, might be due to homoplasy or farming exercises such as animal importation. Inclusion of further local isolates in next studies will help to assess these assumptions.