Table 2. Differentiating characteristics of HA-MRSA and CA-MRSA.

HA-MRSA: hospital-acquired methicillin-resistant Staphylococcus aureus; CA-MRSA: community-acquired methicillin-resistant Staphylococcus aureus

	CA-MRSA	HA-MRSA
At-Risk Populations	Children, prisoners, homeless, homosexual males, soldiers, intravenous drug users, general population	Healthcare facility residents, diabetics, hospitalized patients, ICU patients
SCCmec subtype	IV, V	I, II, III
Resistant against	Beta-lactam drugs (oxacillin, penicillin), erythromycin	Usually multidrug resistance, tend to be susceptible to TMP-SMX, macrolides, tetracyclines
PVL toxin	Present in >95% of cases	Rare (5%)
Clinical Affiliation	Post-influenza necrotizing pneumonia, osteomyelitis	Nosocomial pneumonia, Catheter-acquired UTI, Bacteremia
Discovered	1980s	1961