Microbiologic Response With Linezolid And Vancomycin In Ventilator-Associated Pneumonia Due To Methicillin Resistant Staphylococcus Aureus

Inclusion Criteria: * The patient must have or be suspected of having a ventilator-associated pneumonia (VAP) due to MRSA. * Patient must be hospitalized for at least 5 days, must be ventilator-dependent ≥ 48 hours prior to screen/baseline, and anticipated to remain on the ventilator for 72 hours after enrollment so follow-up BAL can be performed. * Clinical picture compatible with pneumonia (acquired during ventilation) * Chest X Ray at baseline/screen or within 24 hours of initiation of therapy must be consistent with diagnosis of pneumonia Exclusion Criteria: * Hypersensitivity to linezolid, vancomycin, or one of the excipients in any of these drug formulations. * Infections due to gram-positive organisms known to be resistant to either of the study drugs. * Any antibiotic used in the treatment of MRSA, such as vancomycin, TMP/SMX, rifampin, or linezolid, for more than 48 hours prior to patient's enrollment into the study. * Patients with neutropenia, AIDS, lymphoma or anticipated chemotherapy. * Patients who have long-term tracheostomy (for more than 60 days). Acute tracheostomy patients are allowed.