It can produce bronchopneumonia or lung abscess following influenza, may give rise to lung abscesses in intravenous drug abusers and is an important cause of nosocomial pneumonia. Most strains are penicillinase producers and some are methicillin resistant. Such strains are commonly resistant to many other antibiotics. Mycoplasma pneumoniae Mycoplasmas are bacteria which lack rigid cell walls. They can be grown in the laboratory on special culture media but will not be grown on routine examination of samples.
Diagnosis is clinical, radiological and by serological blood tests.
Mycoplasma years , where many cases are seen, occur every three to four years, alternating with periods when few, if any, such infections occur. Legionella pneumophila A Gram-doubtful rod which can be grown only on specialised culture media and will be missed on routine laboratory examination. The organism occurs in standing water ubiquitously and causes infection only when water vapour with a heavy bacterial load is inhaled. Minor infection is common and largely unrecognised. Diagnosis is clinical, radiological and serological or by antigen detection.