Purification of Staphylococcus aureus and Streptococcus uberis Antigens to Promote Bovine Vaccine Development

Mastitis in dairy cows is an inflammation of the udder with significant agricultural impacts worldwide. Subclinical mastitis is often caused by Staphylococcus aureus and Streptococcus uberis. S. aureus is a leading cause of opportunistic infection in humans and an effective vaccine will have implication for veterinary and human health. One approach for vaccine development is to target the surface adhesins of S. aureus. The adhesins, IsdA and ClfA, are conserved among human and bovine S. aureus. IsdA and ClfA were used to design a mucosal vaccine based on cholera toxin A2/B fusions (CTA2/B), which was administered intranasally to dairy cows in a clinical trial. A total of 22 cows were vaccinated and humoral response was examined from serum and milk using purified IsdA and ClfA in ELISA. Additionally, two antigens from S. uberis were cloned into a vector expressing CTA2/B for purification and incorporation into a multivalent vaccine. This research represents essential steps toward the advancement of a safe amd effective vaccine to prevent bovine mastitis