Expanded serotyping scheme for Ureaplasma urealyticum strains isolated from humans.

For the last decade the serological heterogeneity of strains of Ureaplasma urealyticum isolated from humans has been represented by eight serotypes. We have identified two additional serotypes, strains Vancouver and Western. Using a modified metabolic inhibition test and a colony indirect epifluorescence method, we tested antisera to the above 10 types against the 11 members of the independent Lin-Kass classification. Four of the latter, K2, U24, U26, and U38, showed unique specificities; these were confirmed by reciprocal testing with antisera prepared against the respective strains. With the addition of these strains, the serotyping scheme now has 14 members. Since this expanded classification allows greater discrimination between strains, it will allow also for their future characterization. It provides, in addition, a potentially more effective epidemiological tool.