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Prevalence of the 2 ureaplasma biovars was estimated in patients with genital tract infections by polymerase chain reaction targeting the urease and multiple-banded antigen gene. Ureaplasma was more frequently isolated in symptomatic than asymptomatic subjects (48% versus 22%) (P=0.001). Biovar 1 was predominant; however, there was no difference in the distribution of the 2 biovars between the symptomatic and asymptomatic subjects.

Studies of epidemiology and pathogenesis of infections with Ureaplasma have received much attention in recent years. Rapid molecular methods for serotyping of Ureaplasma parvum will be of great value in the studies. We developed 2 multiplex real-time TaqMan polymerase chain reaction systems that allow simultaneous detecting and serotyping of 4 serovars of U. parvum.

Evidence has been presented that the species currently known as Ureaplasma urealyticum should be separated into 2 species-Ureaplasma parvum (previously, U. urealyticum biovar 1) and U. urealyticum (previously, U. urealyticum biovar 2). Differentiation and quantification of U. parvum and U. urealyticum can provide important information of the epidemiology of Ureaplasma infections. We developed 2 real-time TaqMan polymerase chain reaction (PCR) assays that would allow rapid, specific, sensitive, quantitative detection and convenient differentiation of U. parvum and U. urealyticum. One hundred twenty-eight clinical specimens were studied and compared with results obtained by culture methods and conventional PCR. The positive rate of real-time TaqMan PCR (59.4%, 76 of 128) was higher than that of culture methods (42.2%, 54 of 128) and conventional PCR (50%, 64 of 128). Of 76 positive specimens, 86.8% (66) contained U. parvum only, 10.5% (8) contained U. urealyticum only, and 2.6% (2) contained both. The copy numbers of 11 positive specimens were in the range of 10(1) to 10(3) copies per reaction mixture, 18 in the range of 10(3) to 10(5), and 47 in the range of 10(5) to 10(8). In the future, quantitative detection and convenient differentiation of real-time TaqMan PCR assays will assist in the study of the pathogenesis and epidemiology of Ureaplasma infections.

We describe the first use of pulsed field gel electrophoresis to genotype human Ureaplasma species. This technique can distinguish between U. urealyticum and U. parvum, differentiate most of the 14 serovars from one another, and identify differences among clinical isolates of the same serovar.

A newly developed enzyme linked immunosorbent assay (ELISA) method using monoclonal antibodies (MAbs) to the 14 serotypes of Ureaplasma urealyticum was compared to immunofluorescence assay (IFA) for serotyping U. urealyticum clinical isolates. Of the 102 vaginal isolates of U. urealyticum, five strains were lost and were excluded from analysis. Of the 97 strains analysed, a total of 86 (89%) strains were typeable by ELISA and a total of 89 (92%) strains were typeable by IFA. Eighty-six strains were typeable by both methods, three by IFA only and eight strains were not typeable neither by ELISA nor by IFA. Of the 86 strains typeable by both methods, complete concordance in serotyping results was found. The three strains not typeable by ELISA were typeable as serotype 4 by IFA. These three strains were reanalysed by ELISA after major modifications of the antigen preparation and were typeable as serotype 4. In conclusion, the ELISA was found suitable for serotyping clinical isolates. However, since the ELISA had a somewhat lower performance than IFA, strains not typeable by ELISA, should be retested by another technique such as IFA.