title: Community acquired methicillin resistant Staphylococcus aureus pneumonia: an update for the emergency and intensive care physician.
abstract: Pneumonia caused by community-acquired (CA) methicillin-resistant Staphylococcus aureus (MRSA) among individuals without healthcare-associated (HA) risk factors was first recognized a decade ago. CA-MRSA has now been established as a pathogen responsible for rapidly progressive, frequently fatal disease manifesting as necrotizing pneumonia, severe sepsis and necrotizing fasciitis. The frequency of occurrence, risk factors, and optimal treatment of CA-MRSA pneumonia remain unclear and vary significantly across countries. CA-MRSA is resistant to β-lactam antimicrobials due to the acquisition of novel methicillin resistance genetic cassettes. Additionally many CA-MRSA strains produce Panton-Valentine leukocidin (PVL), due to which they probably exceed the virulence of hospital-acquired MRSA isolates (HA-MRSA). CA-MRSA pneumonia requires early suspicion -especially in young otherwise healthy individuals with rapidly evolving clinical picture presenting with cavitary consolidation, bilateral infiltrates, pleural effusion and hemoptysis. Prompt hospitalization and aggressive treatment with intravenous antibiotics is warranted to improve outcomes. Therapeutic approach for severe CA-MRSA infections and particularly pneumonia is generally the same as that for invasive HA-MRSA infections. New anti-MRSA agents and possible combinations are of great importance to be evaluated in the future.
authors.affiliation: Department of Critical Care Medicine, University Hospital Attikon, Medical School University of Athens, Athens, Greece.
authors.forename: I
authors.initials: I
authors.lastname: Karampela
authors.forename: G
authors.initials: G
authors.lastname: Poulakou
authors.forename: G
authors.initials: G
authors.lastname: Dimopoulos
mesh_terms: D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology / Q000628:therapy*; D003422:Critical Care; D024881:Drug Resistance, Bacterial; D004632:Emergency Medical Services; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D055624:Methicillin-Resistant Staphylococcus aureus / Q000472:pathogenicity; D011023:Pneumonia, Staphylococcal / Q000453:epidemiology / Q000382:microbiology / Q000628:therapy*
chemical_list: D016756:Immunoglobulins, Intravenous