The identification of six novel proteins with fibronectin or collagen type I binding activity from Streptococcus suis serotype 2.

Streptococcus suis, a major swine pathogen, is an emerging zoonotic agent that causes meningitis and septic shock. Bacterial cell wall and secreted proteins are often involved in interactions with extracellular matrix proteins (ECMs), which play important roles in the initial steps of pathogenesis. In this study, 2D SDS-PAGE, western blotting-based binding affinity measurements, and microtiter plate binding assays were used to identify cell wall and secreted proteins from S. suis that interact with fibronectin and collagen type I. We identified six proteins from S. suis, including three proteins (translation elongation factor G, oligopeptide-binding protein OppA precursor, and phosphoglycerate mutase) that show both fibronectin and collagen type I binding activity. To the best of our knowledge, these three newly identified proteins had no previously reported fibronectin or collagen type I binding activity. Overall, the aim in this study was to identify proteins with ECM binding activity from S. suis and it represents the first report of six new proteins from S. suis that interact with fibronectin or collagen type I.