DESCRIPTION OF AN ALBUMIN-BINDING ACTIVITY FOR STREPTOCOCCUS-SUIS SEROTYPE-2

This study was undertaken to investigate the binding activity of Strep tococcus suis serotype 2 to albumin. Using flow cytometry we observed a binding activity of S. suis to albumin for virulent as well as for a virulent isolates. Western immunoblots analysis revealed that a 39-kDa S. suis protein was responsible, at least in part, for this binding a ctivity. This protein showed high N-terminal homology (95.6% for the f irst 23 residues) with a group A Streptococcus glyceraldehyde-3-phosph ate dehydrogenase. Furthermore, the addition of albumin to the culture broth resulted in an increase in the virulence of S. suis strains in mice. These results suggest that an interaction with albumin could pla y a role in the pathogenesis of S. suis serotype 2 infections.