Ventilator-Associated Pneumonia/Hospital-Acquired Pneumonia Requiring Mechanical Ventilatory Support

Inclusion Criteria: * Onset or exacerbation of pneumonia at least 72 hours after admission to an acute care facility or onset of pneumonia in a nursing home or rehabilitation facility with subsequent transfer to an acute care facility * Diagnosis of hospital-acquired pneumonia requiring mechanical ventilatory support * Patient or Patient's legal guardian must sign written informed consent for study participation, pretreatment, and Day 7 bronchoscopy Exclusion Criteria: * Patients with hospital-acquired pneumonia caused by pathogens resistant to MERREM * Patients with allergies to cephalosporins, penicillins and carbapenems * Patients taking anticonvulsant therapy for a known seizure disorder * Patients with lung cancer * Patients with cystic fibrosis, acquired immune deficiency syndrome (AIDS), neutropenia, active tuberculosis, or patients taking immunosuppressive therapy in preparation for or following an organ transplant. * Patients who are pregnant or breast feeding * Patients who are unlikely to survive * Patients with certain infections in another area requiring treatment with additional antibiotics * Patients with other underlying conditions that would make it difficult to interpret response to study drug. * Patients who have been part of another clinical study 30 days before entry into this study. * Patients with hypotension (systolic BP \< 85mmHg) or acidosis (arterial pH \<7.25 or serum bicarbonate \<15 mg/dl) despite attempts at fluid resuscitation * Patients with profound hypoxia