Reductive evolution of virulence repertoire to drive the divergence between community- and hospital-associated methicillin-resistant of the ST1 lineage.

Methicillin-resistant (MRSA) of the ST1-SCCIV lineage has been associated with community-acquired (CA) infections in North America and Australia. In Brazil, multi-drug resistant ST1-SCCIV MRSA has emerged in hospital-associated (HA) diseases in Rio de Janeiro. To understand these epidemiological differences, genomic and phylogenetic analyses were performed.