An international team led by investigators at the Massachusetts Eye and Ear Infirmary reports in the American Society for Microbiology journal mBio this week on its comparative genomic analysis of vancomycin-resistant Staphylococcus aureus strains. The researchers specifically focused on the strains' positions within the clade most commonly associated with hospital-acquired methicillin-resistant S. aureus infection in the US — clonal cluster 5, or CC5.