Comparison of the efficacy of egg yolk extract and horse serum for growth of Mycoplasma pneumoniae.

The usefulness of chicken egg yolk extract as a substitute for horse serum in culture media for Mycoplasma pneumoniae was investigated. As a growth-supporting factor in the growth medium for M. pneumoniae and some other mycoplasmal species, the primary isolation medium for M. pneumoniae, and the metabolism-inhibition test medium for diagnosis of M. pneumoniae infection, egg yolk extract may be an excellent substitute for horse serum. The particular superiority of egg yolk extract to horse serum is that egg yolk extract, unlike horse serum, did not show any inhibitory effect on the growth of M. pneumoniae.