Modified metabolic inhibition test for serotyping strains of Ureaplasma urealyticum (T-strain Mycoplasma)

Antisera prepared against the eight recognized serotypes of Ureaplasma urealyticum were tested against the homologous and heterologous antigens by a modified metabolic inhibition test that used bromothymol blue broth in microtiter plates. The method gives clear endpoint determinations which are usually maintained on continued incubation. Antisera against serotype 8 showed cross-reactions with types 2 and 4. The ninth strain, Vancouver, when tested by this method did not fit the recognized serotyping scheme and may represent a new serotype.