Unexpected genetic diversity of Mycoplasma agalactiae caprine isolates from an endemic geographically restricted area of Spain
1 Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo s/n, 30100, Murcia, Spain
2 UMR Mycoplasmoses des Ruminants, Anses, Laboratoire de Lyon, 31 Avenue Tony Garnier, 69364, Lyon Cedex 07, France
3 INRA, UMR 1225, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076, Toulouse Cedex 3, France
4 Université de Toulouse, INP-ENVT, UMR 1225, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076, Toulouse Cedex 3, France
BMC Veterinary Research 2012, 8:146 doi:10.1186/1746-6148-8-146Published: 27 August 2012
The genetic diversity of Mycoplasma agalactiae (MA) isolates collected in Spain from goats in an area with contagious agalactia (CA) was assessed using a set of validated and new molecular typing methods. Validated methods included pulsed field gel electrophoresis (PFGE), variable number of tandem repeats (VNTR) typing, and Southern blot hybridization using a set of MA DNA probes, including those for typing the vpma genes repertoire. New approaches were based on PCR and targeted genomic regions that diverged between strains as defined by in silico genomic comparisons of sequenced MA genomes.
Overall, the data showed that all typing tools yielded consistent results, with the VNTR analyses being the most rapid method to differentiate the MA isolates with a discriminatory ability comparable to that of PFGE and of a set of new PCR assays. All molecular typing approaches indicated that the Spanish isolates from the endemic area in Murcia were very diverse, with different clonal isolates probably restricted to separate, but geographically close, local areas.
The important genetic diversity of MA observed in infected goats from Spain contrasts with the overall homogeneity of the genomic background encountered in MA from sheep with CA in Southern France or Italy, suggesting that assessment of the disease status in endemic areas may require different approaches in sheep and in goats. A number of congruent sub-typing tools are now available for the differentiation of caprine isolates with comparable discriminatory powers.