Staphylococcus aureus is widely recognized as the most significant nosocomial pathogen due to its virulence potential and because the species has acquired resistance to almost all current antibiotics. S. aureus is also an important cause of community-acquired sepsis worldwide. MRSA bacteraemia rates in the UK and internationally remain high and MRSA is endemic in many units despite widely publicized control regimens prompted by public concerns. Although it is known that in the UK >95% of nosocomial MRSA bacteraemia is caused by one of two major MRSA lineages, we know relatively little about...