Physiological consequences of Piscine Orthoreovirus (PRV) infection of Atlantic and Pacific salmonids

16-1-P-03

Description

The common occurrence of piscine orthoreovirus (PRV) among salmonids has raised questions about the physiological performance and overall health of infected wild and farmed salmon. PRV has been shown to primarily infect blood cells (erythrocytes) which in some instances can result in heart and skeletal muscle inflammation (HSMI) or other pathological conditions affecting the respiratory system. Critical to assessing the potential impacts of PRV infections are controlled infection studies that measure physiological impairment to critical life support systems.

In this study, we conducted controlled laboratory infection studies to measure multiple respiratory indices to test the hypothesis that a low-virulence strain of PRV-1 from Pacific Canada compromises the cardiorespiratory capabilities of Atlantic salmon and Sockeye salmon.

Results of the study help to inform Fisheries and Oceans Canada management strategies for PRV.

Findings

Results were contrary to the hypothesis that a low-virulence strain of PRV-1 from Pacific Canada compromises the cardiorespiratory capabilities of Atlantic salmon and Sockeye salmon. Oxygen affinity and carrying capacity of erythrocytes were unaffected by PRV, despite the presence of high load infections, minor heart pathology and transient cellular activation of antiviral response pathways. Similarly, PRV-infected fish had neither sustained nor have significant differences in respiratory capabilities compared with control fish. The lack of functional harm to salmon infected with PRV from Pacific Canada implies PRV-1 load is not a suitable predictor of disease within a host organism.

Publications

Zhang, Y., Polinski, M. P., Morrison, P. R., Brauner, C. J., Farrell, A. P., & Garver, K. A. 2019. High-load reovirus infections do not imply physiological impairment in salmon. Frontiers in Physiology 10, 114.

Program name

Aquaculture Collaborative Research and Development Program (ACRDP)

Years

2016-2018

Principal investigator

Kyle Garver, research scientist, Fisheries and Oceans Canada, Pacific Biological Station, Pacific Region
Email: Kyle.Garver@dfo-mpo.gc.ca

Team member(s)

Mark Polinski, Visiting Fellow, Fisheries and Oceans Canada, Pacific Biological Station, Pacific Region

Anthony Farrell, Professor, University of British Columbia

Colin Brauner, Professor, University of British Columbia

Collaborator(s)

Jeremy Dunn, Executive Director, BC Salmon Farmers Association