Hybrid ST71 genomes identified in a ruminant-associated clone of Staphylococcus aureus

Population genetic studies have shown that natural S. aureus populations are clonal and largely host-adapted, although homologous recombination events have been shown to play a role in the evolution of successful lineages, such as the HA-MRSA clone ST239, which has arisen as the result of a large-scale recombination event between ST8 and ST30 parent lineages. Currently, the role of recombination in the evolution of animal-associated S. aureus lineages is not known. In this study, phylogenetic analysis, recombination detection and comparative genomic analysis of bovine ST71 strains compared to the strains of the predicted ST97 ancestral genotype indicates that ST71 is comprised of a mosaic genome.