UREAPLASMA-UREALYTICUM BIOVAR SPECIFICITY AND DIVERSITY ARE ENCODED IN MULTIPLE-BANDED ANTIGEN GENE

Ureaplasma urealyticum is a commensal organism of the lower genital tr act of females, but in a subpopulation of individuals, it can invade t he upper genital tract. It is a significant cause of chorioamnionitis and neonatal morbidity and mortality. There are 14 recognized serovars of U. urealyticum; these can be divided into two distinct clusters or biovars. Biovar 1 is composed of serovars 1, 3, 6, and 14. Biovar 2 i s composed of serovars 2, 4, 5, 7, 8, 9, 10, 11, 12, and 13. We previo usly identified a surface antigen, the multiple-banded (MB) antigen, w hich contains both serovar-specific and cross-reactive epitopes. Genot ypic characterization Of the C-terminal region of the MB antigen of se rovar 3 indicates that serovar specificity and MB antigen size variati on reside in that domain. In the present study, we used PCR analysis,v ith primers derived from the serovar 3 MB antigen gene DNA sequence to determine if the MB antigen gene was present in the remaining 13 refe rence serovars as well as in invasive clinical isolates. The results i ndicated that not only was the MB antigen gene present in all serovars but that the genes' 5' regions were markers of biovar specificity and diversity. Further analysis of this region should reveal the phylogen etic relationship among serovars of U. urealyticum and, possibly, thei r invasive potential.