Presence or absence of risk factors for MRSA determines whether or not MRSA drug therapy is used7. If a patient is thought to have pneumonia and they possess risk factors for MRSA, then antimicrobial therapy active against MRSA will be used empirically and "de-escalated" if objective culture data does not demonstrate MRSA. Empiric or culture-based therapy for MRSA HAP includes one of the following: 1) the glycopeptide vancomycin or 2) the oxazoladinone linezolid (Zyvox®). Antimicrobials with activity against MRSA but who do not currently have licensed indication for use in HAP include: 3) the glycylcycline, tigecycline (Tygacil®) and 4) the streptogramin, quinupristin-dalfopristin (Synercid®).