Vaccine against Staphylococcus aureus for bovine mastitis prevention

Purpose and goal

The purpose of the project has been to investigate the conditions for using fusion proteins as a vaccine against S aureus infections. Bovine mastitis has primarily been the target group. However, a vaccine against bovine S aureus mastitis is also important for the development of vaccine against human infections. The fusion proteins produced have been shown to be good candidates to be used as vaccine. Antibodies target proteins that are important for the pathogenesis of bacteria. The fusions have been designed with the aim of facilitating large-scale purification and stability

Expected results and effects

The results strengthens the view that fusion proteins with many short parts are suitable as vaccines. Antibodies are formed against many functions and structures of importance for the bacterial pathogenesis. The parts selected from the included proteins are chosen so that purification and stability are promoted, which works well here. The manufacturing of veterinary vaccines must be cost effective, as the results indicate. Many previous experiments described in the literature to vaccinate against S aureus infections have failed because too few antigens were included.

Planned approach and implementation

In total, we have expressed 6 fusion proteins where parts of 20 different proteins are included. From the included proteins, only very short parts are included, selected for the expected immunogenicity, structure and compatibility. Two of the fusion proteins have been immunized in rabbits. The antibody level has been measured against each of the constituent components as "single" protein. The analysis shows that constituent parts each have good immunogenicity and that the antibodies should have a function to block the infectious process.