Bacterial membrane vesicles: toxic or an improvement to fish health

Aquaculture is one of Norway`s most important sources for export next after oil and gas. This has been achieved amongst other means by the successful development of vaccines for fish against disease causing agents. Still, infectious diseases caused by viral, bacterial and parasites, is one of the major challenges in the aquaculture industry today. Our research laboratory at School of Pharmacy, University of Oslo has during the last years pursued investigations into the fundamentals of new vaccine technologies against intracellular bacterial infections. We have ongoing discussion with international pharmaceutical companies within animal healthcare in development of this technology which is based on the biogenesis of extracellular vesicles (MVs) secreted from the bacterial body. During these investigations we have discovered a differential toxicity against both these vesicles and bacteria in the primary host, the Atlantic salmon, as well as in our zebrafish infection model. It is unclear whether this is caused by the layer of lipopolysaccharides (LPS) on this Gram-negative outer membrane. The evaluation of the LPS toxicity is of uttermost importance as this will largely effect the utilization and production of the vaccine technology. In the proposed project a guest researcher from Chile will travel to Oslo to perform these experiments using our available Atlantic salmon cell line and zebrafish infection model. He will also interact with researchers in Norway and transfer his know-how for P. salmonis pathogenesis. This will be highly beneficial and make large advancements within this field that would benefit both Norway and Chile, two of the major players within aquaculture of salmonids in the world.