Community-acquired pneumonia pneumonia not seen on x-rays. However, congestive heart failure or other types of lung damage can mimic CAP on x-rays. Several tests can identify the cause of CAP. Blood cultures can isolate bacteria or fungi in the bloodstream. Sputum Gram staining and culture can also reveal the causative microorganism. In severe cases, bronchoscopy can collect fluid for culture. Special tests can be performed if an uncommon microorganism is suspected, such as urinalysis for Legionella antigen in Legionnaires' disease. CAP is treated with an antibiotic that kills the offending microorganism and by managing complications. If the causative microorganism is unidentified (often
Pneumocystis pneumonia The older species name "Pneumocystis carinii" (which now applies only to the "Pneumocystis" species that is found in rats) is still in common usage. As a result, "Pneumocystis" pneumonia (PCP) is also known as Pneumocystis jiroveci[i]" pneumonia and (incorrectly) as Pneumocystis carinii" pneumonia. Regarding nomenclature, when the name of "Pneumocystis" pneumonia (PCP) changed from "P. carinii" pneumonia to "P. jirovecii" pneumonia, it was at first asked whether "PJP" should replace "PCP". However, because the short name "PCP" was already well established among physicians that managed patients with "Pneumocystis" infection, it was widely accepted that that name could continue to be