MRSA nasal swab PCR to de-escalate antibiotics in the emergency department.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) nasal swab polymerase chain reaction (PCR) assay has a 96.1-99.2% negative predictive value (NPV) in pneumonia and may be used for early de-escalation of MRSA-active antibiotic agents.