Within the next few years the work of two doctoral students will provide new knowledge about PRV that may lead to a breakthrough in developing vaccines against the costly salmon disease HSMI. (Photo: VESO Vikan)
In 2010 researchers discovered a link between piscine orthoreovirus (PRV) and the salmon disease HSMI. The virus appears to occur frequently in farmed salmon around the world. The growing number of HSMI outbreaks has producers, vaccine companies and researchers mobilising to learn more about the impact of the virus on fish health. The Research Council of Norway’s HAVBRUK programme is providing funding for two doctoral fellows who are adding to the knowledge pool.
Basis for new knowledge
Hanne Merethe Haatveit’s doctoral work is establishing an important knowledge base for tackling challenges in salmon aquaculture from PRV. (Photo: Torkil Marsdal Hanssen)
Hanne Merethe Haatveit is pursuing her Ph.D. at the Norwegian University of Life Sciences (NMBU). Her doctoral work in the research projects ViVaFish and PRV PROTect (see below) is establishing an important knowledge base for tackling PRV and other challenges facing salmon aquaculture.
“Up to now we haven’t been able to efficiently replicate the virus in laboratories,” explains Ms Haatveit. “The PRV virus replicates in red blood cells, so we are working on developing a system for laboratory cultivation of red blood cells from salmon, where we can study how the virus replicates.”
The ability to replicate the virus is essential for understanding not only the microorganisms’ capacity to cause disease but also how the salmon immune system responds and how the virus is transmitted between hosts.
“Our objective is to create a reverse genetic system for the PRV virus,” continues Ms Haatveit. “That will enable us to manipulate the virus and produce live but weakened viruses for vaccines. We have found proteins that could be promising for vaccine developers.”
May reduce major losses
PRV is suspected of being associated with the salmon disease HSMI. Morten Lund is investigating this connection as well as any significance the virus may have for PD and CMS. (Photo: Torkil Marsdal Hanssen)
At the Norwegian Veterinary Institute, doctoral fellow Morten Lund is working to clarify the effect of PRV infections in the red blood cells of farmed salmon. He is also affiliated with the PRV PROTect project.
“Among other things, I am investigating how infection affects fish capacity to deal with oxygen deficiency, smoltification and stress as well as other infections,” says Mr Lund.
He is seeking answers through challenge trials and other methods at the VESO Vikan aquatic research facility. It is critical to establish whether PRV actually causes HSMI. Together with pancreas disease (PD) and cardiomyopathy syndrome (CMS), HSMI is one of the most destructive viral diseases in Norwegian salmon aquaculture.
“It is possible that PRV infection may weaken the fish in different ways from those previously described for HSMI,” continues Mr Lund. “My doctoral study will help to develop tools for mapping viruses and optimising strategies for dealing with infected fish on-site.”
Heart and skeletal muscle inflammation (HSMI)
Heart and skeletal muscle inflammation (HSMI) is a disease in farmed Atlantic salmon. So far confirmed cases have only been diagnosed in Norway. The bulk of outbreaks has occurred in central Norway, but recent years have seen many outbreaks in North Norway as well.
Source: Norwegian Veterinary Institute.
Facts about the main projects
Platform for Fish Virus Vaccines (ViVaFish)
Norwegian University of Life Sciences
Targeting piscine orthoreovirus (PRV) infection in Norwegian Atlantic salmon aquaculture (PRV PROTect)
PatoCen Analyse AS
Aquaculture - An Industry in Growth
The Research Council of Norway’s HAVBRUK programme develops knowledge to promote the sustainable growth of Norwegian aquaculture and assist in maintaining and further developing Norway’s position as the world’s leading seafood nation. The programme places high priority on educating future aquaculture researchers.