Bacterial Ghosts as a vaccine for the prevention of cold water disease affecting the salmonid aquaculture industry

The objective of this proposal is to demonstrate the feasibility of utilizing bacterial ghosts (BG) as novel vaccines for aquaculture. Current vaccination strategies for the prevention of aquaculture diseases utilize traditional technologies including chemical or heat inactivation of cultured pathogens or live attenuated strains of pathogens. While some of these vaccines have proved to be efficacious, others have demonstrated sub-par immunogenicity and protection. BG are non-living Gram negative bacterial cell envelopes created after lysis with the cloned bacteriophage gene E. Production of BG does not alter the natural protein components of the cell, including many proteins important for interaction with immune system cells including dendritic cells and macrophages. Additionally, since BG retain these structures, they do not require the addition of adjuvant to induce an immune response In this Phase I proposal the feasibility of producing a BG based vaccine for use in the aquaculture industry will be assessed. To determine whether this is feasible, BG will be created from a known important aquaculture pathogen, Flavobacterium psychrophilum. F. psychrophilum is the etiologic agent of cold water disease which affects commercial aquaculture species such as rainbow trout and salmon. To date, there is no effective vaccine against this pathogen and development of such a vaccine is of great importance to the cold water aquaculture industry. F. psychrophilum BG will be tested for efficacy using a challenge model in trout. The long-term goal of this project is to develop safe and effective BG vaccine for commercialization and marketing to the aquaculture community.