Patient description: A 31 yo male with no significant past medical history presents with productive cough and chest pain. He reports developing cold symptoms one week ago that were improving until two days ago, when he developed a new fever, chills, and worsening cough. He has right-sided chest pain that is aggravated by coughing. His wife also had cold symptoms a week ago but is now feeling well. Vitals signs include temperature 103.4, pulse 105, blood pressure 120/80, and respiratory rate 15. Lung exam reveals expiratory wheezing, decreased breath sounds, and egophany in the left lower lung field.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Bacterial Pneumonia Written informed consent by the subject/subject's LAR Hospitalized males or females ≥ 18 yrs with respiratory failure requiring mechanical ventilation and clinical suspicion of HABP, HCAP or VABP Onset or exacerbation of pneumonia at least 48 hours after admission to any patient health care facility or onset of pneumonia in a nursing home or rehabilitation facility with subsequent transfer to an acute care facility Women of childbearing potential if their pregnancy test is negative Subjects who have received previous antibacterial therapy within 14 days of pre-treatment bronchoscopy entry may be entered only if the subject has not responded clinically.). While less than 24 hours of pre-treatment antibiotics is preferential, recovery of >104 CFU/ml in the quantitative Bronchoscopic BAL will be seen as primary evidence that the prior therapy was not efficacious and enrollment will be allowed.) Patients should have clinical findings that support a diagnosis of HABP/VABP/HCAP Within 48 hours before starting empiric therapy a subject's chest radiograph should show the presence of a NEW or progressive infiltrate, cavitation, or effusion suggestive of pneumonia Within 36 hours before the start of empiric study therapy, a quantitative culture of Bronchoscopic BAL fluid must be obtained Patients with VABP should have a Clinical Pulmonary Infection Score of >/= 5  Subjects with pneumonia caused by pathogens resistant to meropenem (MIC greater than or equal to 16µg/ml) or a prior meropenem therapy failure Subjects with contra-indications to ANY study medication, in particular with known or suspected allergy or hypersensitivity Women who are pregnant or lactating Subjects taking anticonvulsant medications for a known seizure disorder.Patients with a history of seizures, AND who are stabilized on anti-seizure medication, may be enrolled into the study at the discretion of the site investigator Subjects with known or suspected community acquired bacterial pneumonia (CABP) or viral pneumonia; or Subjects with acute exacerbation of chronic bronchitis without evidence of pneumonia Subjects with primary lung cancer or another malignancy metastatic to the lungs Subjects who were previously enrolled in this study Subjects who have had an investigational drug or have used an investigational device within 30 days prior to entering the study Subjects with another focus of infection requiring concurrent antibiotics that would interfere with evaluation of the response to study drug Subjects with cystic fibrosis, AIDS with a CD4 lymphocyte count <200 cells/µl, neutropenia (absolute neutrophil count <500 cells/ml), known or suspected active tuberculosis