Evaluation of PPLO, A7B, E, and NYC agar media for the isolation of Ureaplasma urealyticum and Mycoplasma species from the genital tract.

Four agar media (PPLO, NYC, A7B, and E) which are commonly used for the isolation of urogenital tract Mycoplasma species and Ureaplasma urealyticum were compared by culturing swabs of the endocervix of 334 pregnant women on all four media. To permit growth of both Mycoplasma and U. urealyticum, selective ingredients were omitted from the media tested. A7B and E agar were both satisfactory for the isolation of Mycoplasma species, recovering 92 and 82%, respectively, of all Mycoplasma species isolated. Only A7B agar was satisfactory for U. urealyticum isolation, recovering 96% of all isolates. Several modifications of PPLO, NYC, and E agar failed to significantly improve recovery of U. urealyticum on these media. A7B agar was clearly superior to all other media tested in terms of recovery rate, typical appearance of colonies, and ease of reading. A7B can be used for the isolation of both U. urealyticum and Mycoplasma species from urogenital sites.