|Typical patient||Elderly, debilitated and/or critically or chronically ill||Young healthy people, students, professional athletes and military personnel|
|Infection site||Often bacteraemia with no obvious source of infectionAlso surgical wounds, open ulcers, i.v. lines and catheter urinesMay cause ventilator-associated pneumonia||Predilection for skin and soft tissue producing cellulitis and abscessesMay cause necrotising community-acquired pneumonia, septic shock or bone and joint infections|
|Transmission||Within healthcare settings; little spread among household contacts||Community acquired; may spread in families and sports teams|
|Clinical setting of diagnosis||In an in-patient setting, but increasingly HA-MRSA infections in soft tissue and urine are occurring in primary care||In an outpatient or community setting|
|Medical history||History of MRSA colonisation, infection or recent surgery; admission to a hospital or nursing home; antibiotic use; dialysis, permanent indwelling catheter||No significant medical history or healthcare contact|
|Virulence of infecting strain||Community spread is limited PVL genes usually absent||Community spread occurs easily PVL genes often present, predisposing to necrotising soft tissue or lung infection|
|Antibiotic susceptibility||Often multiresistant with the result that the choice of agents is often very limited||Generally susceptible to more antibiotics than HA-MRSA|
HA-MRSA: hospital-associated methicillin-resistant Staphylococcus aureus; CA-MRSA: community-acquired methicillin-resistant Staphylococcus aureus. PVL: Panton–Valentine leukocidin. Reproduced from 17 with permission from the publisher.