Mycoplasma pneumoniae, A Tale of 50 Years.

The bacteriological study of the nasopharyngeal, throat, per nasal tracheal aspirate, and percutaneous lung aspirate was non-contributory, and virological examinations failed to yield a viral agent. Meanwhile the child received treatment with penicillin and streptomycin for 8 days. She became afebrile on 7th day of hospitalization, and her respiratory findings, adenopathy and splenomegaly disappeared while the liver receded to 2 cm below costal margin. The throat swab specimen after being stored at –20 oC to –70 oC for 27 days was examined for M. pneumoniae by inoculating on agar plates and diphasic medium, and its growth was confirmed on the 7th day of first agar subculture. On day 14 of incubation in diphasic medium, a drop in pH (glucose fermentation) and spherular colonies were observed floating in the media. The colonies demonstrated guinea pig erythrocyte hemolysis (within 48 hours) and sheep cell haemadsorption, properties peculiar to M. pneumoniae. Isolation of M. pneumoniae from throat and tracheal aspirates of this child with pneumonia – whose extensive bacterial and viral investigations were non-contributory – indicated etiological role of M. pneumoniae. The child was treated with demethyl-chlortetracycline. A repeat X-ray 3 month later showed persisting middle lobe infiltrates, although child was asymptomatic.