Inhibition of Streptococcus uberis Invasion Into Bovine Mammary Epithelial Cells by Contact with Purified Adhesion Molecule SuaM

Streptococcus uberis is an important bacterial agent of mastitis that can produce chronic subclinical disease in dairy cattle. Despite improved control measures and understanding of disease mechanisms, S. uberis remains as one of the leading agents of disease and causes considerable economic loss every year worldwide. Mastitis is difficult to treat and prone to recurrence despite antibiotic treatment, therefore, the ideal method of mastitis control is a vaccine. The ability of S. uberis to invade bovine mammary epithelial cells is being explored to explain this chronic infection. One approach for vaccine development is to target the adhesion molecules of S. uberis. The protein SuaM is conserved among bovine S. uberis strains and is an important virulence factor. This antigen from S. uberis was cloned into a vector expressing CTA2/B for purification and incorporation into a multivalent vaccine. In this study, we tested the ability of adhesion molecule (SuaM) to prevent invasion of Mac-T cells by S. uberis bovine strain, which induces acute mastitis. An in vitro culture system of bovine epithelial cells was developed to study the pathogenic effects of S. Uberis and the role of surface protein in adhesion of S. uberis to host cells. This research represents essential steps toward the advancement of a safe, effective and inexpensive vaccine to prevent bovine mastitis