Managing Severe Community-Acquired Pneumonia Due to Community Methicillin-Resistant Staphylococcus aureus (MRSA).

Community-associated methicillin-resistant Staphylococcus aureus (MRSA) is a rare, but significant cause of community-acquired pneumonia (CAP). A number of virulence determinants have been implicated in the development of severe community MRSA pneumonia, characterized by multilobar cavitating necrosis in patients without usual risk-factors for pneumonia. Optimal management is uncertain, and is extrapolated from anecdotal experiences with small case series, randomized studies of hospital-acquired pneumonia, and laboratory investigations using in vitro experiments and animal models of MRSA pneumonia. Adequate clinical suspicion, early diagnosis and administration of appropriate antibiotics are necessary for best patient outcomes, although some patients will still do badly even with early anti-MRSA therapy. Vancomycin or linezolid have been recommended as first-line therapy, possibly in combination with other antibiotics. Newer antibiotics such as ceftaroline are still being evaluated.