title: Nosocomial pneumonia. The challenge of a changing clinical spectrum.
mesh_terms: D003428:Cross Infection / Q000209:etiology*; D006088:Gram-Negative Aerobic Bacteria; D006801:Humans; D007165:Immunosuppression Therapy / Q000009:adverse effects; D011014:Pneumonia / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D013902:Radiography, Thoracic; D012141:Respiratory Tract Infections / Q000150:complications; D013183:Sputum / Q000382:microbiology