Immunoglobulin-binding domains of peptostreptococcal protein L enhance vaginal colonization of mice by Streptococcus gordonii

Protein L, an immunoglobulin-binding protein of some strains of the anaerob ic bacterium Peptostreptococcus magnus, has been hypothesized to be a virul ence determinant in bacterial vaginosis. In order to investigate the role o f protein L in peptostreptococcal virulence, the Ig-binding domains of prot ein L were expressed at the surface of the human oral commensal Streptococc us gordonii. Recombinant streptococci were used in vaginal colonization exp eriments, and protein L-expressing S. gordonii demonstrated enhanced abilit y to colonize the vaginal mucosa. Compared to the control strain, they also persisted for a longer period in the murine vagina. (C) 2001 Academic Pres s.