Hospital-Acquired Pneumonia (HAP) is the second most frequent hospital-acquired infection in the US and Europe and accounts for a large proportion of antibiotics prescribed in hospitals. Conventional methods to identify causative microorganisms (virus, bacteria) are time-consuming and sometimes inaccurate, leading to inadequate treatment in a large proportion of HAP patients. The FILMARRAY® Pneumonia Panel (FA-PP, bioMérieux) is an automated diagnostic device, allowing detection of multiple pathogens and resistance markers in one hour. Strategies combining rapid diagnostic testing and intervention of specialists in infectious diseases (i.e. antimicrobial stewardship -AMS - experts) showed significant synergistic impact on antibiotic use, mortality and costs in bloodstream infections. The trial hypothesis is that a strategy combining antimicrobial stewardship and FA-PP improves quality of care in HAP patients, as compared to antimicrobial stewardship alone. The trial will include patients hospitalized for ≥ 48 hours, aged 18 years or older, who have criteria of pneumonia: new lung infiltrate on a chest-x ray, plus evidence that the infiltrate is of an infectious origin (i.e. new onset of fever and/or purulent sputum and/or leukocytosis and/or decline in oxygenation). After informed consent, participants will be randomly allocated to either the intervention or the control arm. In the control arm, management of HAP patients will include clinical examination and conventional microbiological tests. Antibiotic choice will be discussed between AMS experts and the physician in charge of the patient. In the intervention arm, in addition to the procedures above, the strategy will include rapid testing using the FA-PP on a respiratory specimen, obtained by either invasive or non-invasive sampling. No additional invasive procedures will be required for the study, and FA-PP will be performed on samples collected as part as routine care. Investigators will visit the patient at inclusion, on day 3 and on day 30 (or at hospital discharge) to collect data on comorbidities, clinical outcomes, results of microbiological tests and antibiotics. At the end of follow-up, we will compare the number of days on broad-spectrum antibiotics, the incidence of negative outcomes, the length of stay and costs in the two arms. The use of the FA-PP is expected to prompt early adjustment of antibiotic therapy, improve outcomes, decrease length of stay, and to reduce the use of broad-spectrum antibiotics. The antibiotic saving may reduce the selection pressure, incidence of colonization with multidrug-resistant bacteria and incidence of hospital-acquired superinfections, both at an individual and hospital level. Moreover, this trial relies on the intervention of multidisciplinary AMS teams that are currently being implemented in many health facilities. Their transversal position offers opportunities for recruitment of patients from a wide range of medical and surgical departments. This project evaluates the feasibility of clinical trials based on the intervention of these teams, and will provide a high level of evidence regarding their impact on the prognosis of patients, appropriate use of antibiotics, and antimicrobial resistance.