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Thorarinsson R, Ramstad A, Wolf JC, Sindre H, Skjerve E, Rimstad E, Evensen Ø, Rodriguez JF. Effect of pancreas disease vaccines on infection levels and virus transmission in Atlantic salmon ( Salmo salar) challenged with salmonid alphavirus, genotype 2. Front Immunol 2024; 15:1342816. [PMID: 38515753 PMCID: PMC10955579 DOI: 10.3389/fimmu.2024.1342816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 02/21/2024] [Indexed: 03/23/2024] Open
Abstract
Salmonid alphavirus (SAV) causes pancreas disease (PD), which negatively impacts farmed Atlantic salmon. In this study, fish were vaccinated with a DNA-PD vaccine (DNA-PD) and an oil-adjuvanted, inactivated whole virus PD vaccine (Oil-PD). Controls were two non-PD vaccinated groups. Fish were kept in one tank and challenged by cohabitation with SAV genotype 2 in seawater. Protection against infection and mortality was assessed for 84 days (Efficacy study). Nineteen days post challenge (dpc), subgroups of fish from all treatment groups were transferred to separate tanks and cohabited with naïve fish (Transmission study 1) or fish vaccinated with a homologous vaccine (Transmission study 2), to evaluate virus transmission for 26 days (47 dpc). Viremia, heart RT-qPCR and histopathological scoring of key organs affected by PD were used to measure infection levels. RT-droplet digital PCR quantified shedding of SAV into water for transmission studies. The Efficacy study showed that PD associated growth-loss was significantly lower and clearance of SAV2 RNA significantly higher in the PD-DNA group compared to the other groups. The PD-DNA group had milder lesions in the heart and muscle. Cumulative mortality post challenge was low and not different between groups, but the DNA-PD group had delayed time-to-death. In Transmission study 1, the lowest water levels of SAV RNA were measured in the tanks containing the DNA-PD group at 21 and 34 dpc. Despite this, and irrespective of the treatment group, SAV2 was effectively transmitted to the naïve fish during 26-day cohabitation. At 47 dpc, the SAV RNA concentrations in the water were lower in all tanks compared to 34 dpc. In Transmission study 2, none of the DNA-PD immunized cohabitants residing with DNA-PD-vaccinated, pre-challenged fish got infected. In contrast, Oil-PD immunized cohabitants residing with Oil-PD-vaccinated, pre-challenged fish, showed infection levels similar to the naïve cohabitants in Transmission study 1. The results demonstrate that the DNA-PD vaccine may curb the spread of SAV infection as the DNA-PD vaccinated, SAV2 exposed fish, did not spread the infection to cohabiting DNA-PD vaccinated fish. This signifies that herd immunity may be achieved by the DNA-PD vaccine, a valuable tool to control the PD epizootic in farmed Atlantic salmon.
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Affiliation(s)
| | | | - Jeffrey C. Wolf
- Experimental Pathology Laboratories Inc., Sterling, VA, United States
| | | | - Eystein Skjerve
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Espen Rimstad
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Øystein Evensen
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
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Tsoulia T, Sundaram AYM, Braaen S, Jørgensen JB, Rimstad E, Wessel Ø, Dahle MK. Transcriptomics of early responses to purified Piscine orthoreovirus-1 in Atlantic salmon ( Salmo salar L.) red blood cells compared to non-susceptible cell lines. Front Immunol 2024; 15:1359552. [PMID: 38420125 PMCID: PMC10899339 DOI: 10.3389/fimmu.2024.1359552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 01/23/2024] [Indexed: 03/02/2024] Open
Abstract
Piscine red blood cells (RBC) are nucleated and have been characterized as mediators of immune responses in addition to their role in gas exchange. Salmonid RBC are major target cells of Piscine orthoreovirus-1 (PRV-1), the etiological agent of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar). PRV-1 replicates in RBC ex vivo, but no viral amplification has been possible in available A. salmon cell lines. To compare RBC basal transcripts and transcriptional responses to PRV-1 in the early phase of infection with non-susceptible cells, we exposed A. salmon RBC, Atlantic salmon kidney cells (ASK) and Salmon head kidney cells (SHK-1) to PRV-1 for 24 h. The RNA-seq analysis of RBC supported their previous characterization as pluripotent cells, as they expressed a wide repertoire of genes encoding pattern recognition receptors (PRRs), cytokine receptors, and genes implicated in antiviral activities. The comparison of RBC to ASK and SHK-1 revealed immune cell features exclusively expressed in RBC, such as genes involved in chemotactic activity in response to inflammation. Differential expression analysis of RBC exposed to PRV-1 showed 46 significantly induced genes (≥ 2-fold upregulation) linked to the antiviral response pathway, including RNA-specific PRRs and interferon (IFN) response factors. In SHK-1, PRV induced a more potent or faster antiviral response (213 genes induced). ASK cells showed a differential response pattern (12 genes induced, 18 suppressed) less characterized by the dsRNA-induced antiviral pathway. Despite these differences, the RIG-I-like receptor 3 (RLR3) in the family of cytosolic dsRNA receptors was significantly induced in all PRV-1 exposed cells. IFN regulatory factor 1 (IRF1) was significantly induced in RBC only, in contrast to IRF3/IRF7 induced in SHK-1. Differences in IRF expression and activity may potentially affect viral propagation.
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Affiliation(s)
- Thomais Tsoulia
- Departments of Aquatic Animal Health and Analysis and Diagnostics, Norwegian Veterinary Institute, Ås, Norway
- Department of Biotechnology, Fisheries and Economy, UiT Arctic University of Norway, Tromsø, Norway
| | - Arvind Y. M. Sundaram
- Departments of Aquatic Animal Health and Analysis and Diagnostics, Norwegian Veterinary Institute, Ås, Norway
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Stine Braaen
- Department of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Jorunn B. Jørgensen
- Department of Biotechnology, Fisheries and Economy, UiT Arctic University of Norway, Tromsø, Norway
| | - Espen Rimstad
- Department of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Øystein Wessel
- Department of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Maria K. Dahle
- Departments of Aquatic Animal Health and Analysis and Diagnostics, Norwegian Veterinary Institute, Ås, Norway
- Department of Biotechnology, Fisheries and Economy, UiT Arctic University of Norway, Tromsø, Norway
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Bjørgen H, Malik S, Rimstad E, Vaadal M, Nyman IB, Koppang EO, Tengs T. Correction to: Cellular heterogeneity in red and melanized focal muscle changes in farmed Atlantic salmon (Salmo salar) visualized by spatial transcriptomics. Cell Tissue Res 2024; 395:221. [PMID: 38158442 PMCID: PMC10837211 DOI: 10.1007/s00441-023-03856-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Affiliation(s)
- H Bjørgen
- Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433, Ås, Norway
| | - S Malik
- Department of Breeding and Genetics, 1433, Nofima, Norway
| | - E Rimstad
- Unit of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433, Ås, Norway
| | - M Vaadal
- Department of Breeding and Genetics, 1433, Nofima, Norway
| | - I B Nyman
- Unit of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433, Ås, Norway
| | - E O Koppang
- Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433, Ås, Norway
| | - T Tengs
- Department of Breeding and Genetics, 1433, Nofima, Norway.
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Bjørgen H, Malik S, Rimstad E, Vaadal M, Nyman IB, Koppang EO, Tengs T. Cellular heterogeneity in red and melanized focal muscle changes in farmed Atlantic salmon (Salmo salar) visualized by spatial transcriptomics. Cell Tissue Res 2024; 395:199-210. [PMID: 38087072 PMCID: PMC10837230 DOI: 10.1007/s00441-023-03850-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 11/24/2023] [Indexed: 12/31/2023]
Abstract
Spatial transcriptomics is a technique that provides insight into gene expression profiles in tissue sections while retaining structural information. We have employed this method to study the pathological conditions related to red and melanized focal changes in farmed Atlantic salmon (Salmo salar). Our findings support a model where similar molecular mechanisms are involved in both red and melanized filet discolorations and genes associated with several relevant pathways show distinct expression patterns in both sample types. Interestingly, there appears to be significant cellular heterogeneity in the foci investigated when looking at gene expression patterns. Some of the genes that show differential spatial expression are involved in cellular processes such as hypoxia and immune responses, providing new insight into the nature of muscle melanization in Atlantic salmon.
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Affiliation(s)
- H Bjørgen
- Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433, Ås, Norway
| | - S Malik
- Department of Breeding and Genetics, Nofima, 1433, Ås, Norway
| | - E Rimstad
- Unit of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433, Ås, Norway
| | - M Vaadal
- Department of Breeding and Genetics, Nofima, 1433, Ås, Norway
| | - I B Nyman
- Unit of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433, Ås, Norway
| | - E O Koppang
- Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433, Ås, Norway
| | - T Tengs
- Department of Breeding and Genetics, Nofima, 1433, Ås, Norway.
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Doublet V, Oddie MAY, Mondet F, Forsgren E, Dahle B, Furuseth-Hansen E, Williams GR, De Smet L, Natsopoulou ME, Murray TE, Semberg E, Yañez O, de Graaf DC, Le Conte Y, Neumann P, Rimstad E, Paxton RJ, de Miranda JR. Shift in virus composition in honeybees ( Apis mellifera) following worldwide invasion by the parasitic mite and virus vector Varroa destructor. R Soc Open Sci 2024; 11:231529. [PMID: 38204792 PMCID: PMC10776227 DOI: 10.1098/rsos.231529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 12/13/2023] [Indexed: 01/12/2024]
Abstract
Invasive vectors can induce dramatic changes in disease epidemiology. While viral emergence following geographical range expansion of a vector is well known, the influence a vector can have at the level of the host's pathobiome is less well understood. Taking advantage of the formerly heterogeneous spatial distribution of the ectoparasitic mite Varroa destructor that acts as potent virus vector among honeybees Apis mellifera, we investigated the impact of its recent global spread on the viral community of honeybees in a retrospective study of historical samples. We hypothesized that the vector has had an effect on the epidemiology of several bee viruses, potentially altering their transmissibility and/or virulence, and consequently their prevalence, abundance, or both. To test this, we quantified the prevalence and loads of 14 viruses from honeybee samples collected in mite-free and mite-infested populations in four independent geographical regions. The presence of the mite dramatically increased the prevalence and load of deformed wing virus, a cause of unsustainably high colony losses. In addition, several other viruses became more prevalent or were found at higher load in mite-infested areas, including viruses not known to be actively varroa-transmitted, but which may increase opportunistically in varroa-parasitized bees.
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Affiliation(s)
- Vincent Doublet
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
- Institute for Biology, Martin Luther University Halle-Wittenberg, Halle (Saale) 061200, Germany
| | - Melissa A. Y. Oddie
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala 750 07, Sweden
- Norwegian Beekeepers Association, Kløfta 2040, Norway
| | - Fanny Mondet
- INRAE, UR 406 Abeilles et Environnement, Avignon 84914, France
| | - Eva Forsgren
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala 750 07, Sweden
| | - Bjørn Dahle
- Norwegian Beekeepers Association, Kløfta 2040, Norway
| | - Elisabeth Furuseth-Hansen
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Ås 1432, Norway
| | - Geoffrey R. Williams
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern 3097, Switzerland
- Entomology & Plant Pathology, Auburn University, Auburn, AL 36832, USA
| | - Lina De Smet
- Department of Biochemistry and Microbiology, Ghent University, Ghent 9000, Belgium
| | - Myrsini E. Natsopoulou
- Institute for Biology, Martin Luther University Halle-Wittenberg, Halle (Saale) 061200, Germany
| | - Tomás E. Murray
- Institute for Biology, Martin Luther University Halle-Wittenberg, Halle (Saale) 061200, Germany
| | - Emilia Semberg
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala 750 07, Sweden
| | - Orlando Yañez
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern 3097, Switzerland
| | - Dirk C. de Graaf
- Department of Biochemistry and Microbiology, Ghent University, Ghent 9000, Belgium
| | - Yves Le Conte
- INRAE, UR 406 Abeilles et Environnement, Avignon 84914, France
| | - Peter Neumann
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern 3097, Switzerland
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Ås 1432, Norway
| | - Robert J. Paxton
- Institute for Biology, Martin Luther University Halle-Wittenberg, Halle (Saale) 061200, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103, Germany
| | - Joachim R. de Miranda
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala 750 07, Sweden
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Rennemo J, Berge K, Yousaf MN, Eriksen TB, Welde E, Robertsen C, Johansen B, McGurk C, Rimstad E, Koppang EO, Bjørgen H. An Atypical Course of Cardiomyopathy Syndrome (CMS) in Farmed Atlantic Salmon ( Salmo salar) Fed a Clinical Nutrition Diet. Microorganisms 2023; 12:26. [PMID: 38257853 PMCID: PMC10820600 DOI: 10.3390/microorganisms12010026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 01/24/2024] Open
Abstract
Cardiomyopathy syndrome (CMS) poses a significant threat to farmed Atlantic salmon (Salmo salar), leading to high mortality rates during the seawater phase. Given that controlled experimental challenge trials with PMCV do not reproduce the mortality observed in severe field outbreaks of CMS, field trials on natural CMS outbreaks are warranted. This field study explored the impact of a clinical nutrition intervention, specifically a diet enriched with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on a severe CMS outbreak in a commercial sea farm. CMS was diagnosed in a single sea cage with high mortality rates. Histopathological analysis, RT-qPCR in situ hybridization for virus detection, and fatty acid composition analysis were used to monitor the impact of disease and the inclusion of EPA and DHA in heart tissue. Following the implementation of clinical nutrition, a decline in mortality rates, regression of CMS-associated changes, and a significant reduction in piscine myocarditis virus (PMCV) RNA load were observed within the salmon population. Fatty acid composition analysis of heart samples demonstrated increased levels of EPA and DHA, reinforcing the association between dietary factors, viral load dynamics, and overall fish health. Although further validation is needed in future studies, as field trials may not be sufficient to establish causation, our results indicate that optimizing the EPA + DHA levels may prove beneficial in severe CMS outbreaks.
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Affiliation(s)
- Johan Rennemo
- Skretting AS, 4016 Stavanger, Norway; (J.R.); (K.B.)
| | - Kjetil Berge
- Skretting AS, 4016 Stavanger, Norway; (J.R.); (K.B.)
| | - Muhammad Naveed Yousaf
- Skretting Aquaculture Innovation (AI), 4016 Stavanger, Norway; (M.N.Y.); (T.B.E.); (C.M.)
| | - Tommy Berger Eriksen
- Skretting Aquaculture Innovation (AI), 4016 Stavanger, Norway; (M.N.Y.); (T.B.E.); (C.M.)
| | - Eirik Welde
- Nordlaks Havbruk AS, 8455 Stokmarknes, Norway; (E.W.); (C.R.); (B.J.)
| | - Camilla Robertsen
- Nordlaks Havbruk AS, 8455 Stokmarknes, Norway; (E.W.); (C.R.); (B.J.)
| | - Bjarne Johansen
- Nordlaks Havbruk AS, 8455 Stokmarknes, Norway; (E.W.); (C.R.); (B.J.)
| | - Charles McGurk
- Skretting Aquaculture Innovation (AI), 4016 Stavanger, Norway; (M.N.Y.); (T.B.E.); (C.M.)
| | - Espen Rimstad
- Unit of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1432 Ås, Norway;
| | - Erling Olaf Koppang
- Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1432 Ås, Norway;
| | - Håvard Bjørgen
- Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1432 Ås, Norway;
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Brimsholm M, Rønning L, Rimstad E, Koppang EO, Bjørgen H. Diffuse melanization of the red skeletal musculature in farmed Atlantic salmon (Salmo salar L.). J Fish Dis 2023; 46:453-458. [PMID: 36353756 DOI: 10.1111/jfd.13729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 10/14/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Affiliation(s)
- Malin Brimsholm
- Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | | | - Espen Rimstad
- Unit of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Erling Olaf Koppang
- Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Håvard Bjørgen
- Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
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Su H, van Eerde A, Rimstad E, Bock R, Branza-Nichita N, Yakovlev IA, Clarke JL. Plant-made vaccines against viral diseases in humans and farm animals. Front Plant Sci 2023; 14:1170815. [PMID: 37056490 PMCID: PMC10086147 DOI: 10.3389/fpls.2023.1170815] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 03/14/2023] [Indexed: 06/19/2023]
Abstract
Plants provide not only food and feed, but also herbal medicines and various raw materials for industry. Moreover, plants can be green factories producing high value bioproducts such as biopharmaceuticals and vaccines. Advantages of plant-based production platforms include easy scale-up, cost effectiveness, and high safety as plants are not hosts for human and animal pathogens. Plant cells perform many post-translational modifications that are present in humans and animals and can be essential for biological activity of produced recombinant proteins. Stimulated by progress in plant transformation technologies, substantial efforts have been made in both the public and the private sectors to develop plant-based vaccine production platforms. Recent promising examples include plant-made vaccines against COVID-19 and Ebola. The COVIFENZ® COVID-19 vaccine produced in Nicotiana benthamiana has been approved in Canada, and several plant-made influenza vaccines have undergone clinical trials. In this review, we discuss the status of vaccine production in plants and the state of the art in downstream processing according to good manufacturing practice (GMP). We discuss different production approaches, including stable transgenic plants and transient expression technologies, and review selected applications in the area of human and veterinary vaccines. We also highlight specific challenges associated with viral vaccine production for different target organisms, including lower vertebrates (e.g., farmed fish), and discuss future perspectives for the field.
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Affiliation(s)
- Hang Su
- Division of Biotechnology and Plant Health, NIBIO - Norwegian Institute of Bioeconomy Research, Ås, Norway
| | - André van Eerde
- Division of Biotechnology and Plant Health, NIBIO - Norwegian Institute of Bioeconomy Research, Ås, Norway
| | - Espen Rimstad
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Ralph Bock
- Department III, Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Norica Branza-Nichita
- Department of Viral Glycoproteins, Institute of Biochemistry of the Romanian Academy, Bucharest, Romania
| | - Igor A. Yakovlev
- Division of Biotechnology and Plant Health, NIBIO - Norwegian Institute of Bioeconomy Research, Ås, Norway
| | - Jihong Liu Clarke
- Division of Biotechnology and Plant Health, NIBIO - Norwegian Institute of Bioeconomy Research, Ås, Norway
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Rennemo J, Myrvold S, Berge K, Kileng Ø, Pedersen B, Aksberg DS, Lisik P, Crappe D, McGurk C, Rimstad E, Wessel Ø, Koppang EO, Bjørgen H. In-depth health surveillance and clinical nutrition in farmed Atlantic salmon: a strategic attempt to detect and mitigate an HSMI outbreak. Vet Res 2023; 54:3. [PMID: 36694262 PMCID: PMC9872415 DOI: 10.1186/s13567-023-01137-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/07/2022] [Indexed: 01/26/2023] Open
Abstract
Fish health personnel have limited tools in combatting viral diseases such as heart and skeletal muscle inflammation (HSMI) in open net-pen farmed Atlantic salmon. In this study, we aimed to predict HSMI by intensified health monitoring and apply clinical nutrition to mitigate the condition. We followed a commercial cohort (G1) of Atlantic salmon that was PRV-1 naïve when transferred to a sea cage at a location where HSMI outbreaks commonly occur. The fish in the other cages (G2-G6) at the location had a different origin than G1 and were PRV-1 positive prior to sea transfer. By continuous analysis of production data and sequentially (approximately every fourth week) performing autopsy, RT-qPCR (for PRV-1 and selected immune genes), blood and histological analysis of 10 fish from G1 and G2, we identified the time of PRV-1 infection in G1 and predicted the onset of HSMI prior to any clinical signs of disease. Identical sequences across partial genomes of PRV-1 isolates from G1 and G2 suggest the likely transfer from infected cages to G1. The isolates were grouped into a genogroup known to be of high virulence. A commercial health diet was applied during the HSMI outbreak, and the fish had low mortality and an unaffected appetite. In conclusion, we show that fish health and welfare can benefit from in-depth health monitoring. We also discuss the potential health value of clinical nutrition as a mean to mitigate HSMI.
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Affiliation(s)
- Johan Rennemo
- grid.436785.b0000 0004 0644 9116Skretting AS, Stavanger, Norway
| | | | - Kjetil Berge
- grid.436785.b0000 0004 0644 9116Skretting AS, Stavanger, Norway
| | | | - Børge Pedersen
- grid.436785.b0000 0004 0644 9116Skretting AS, Stavanger, Norway
| | | | - Piotr Lisik
- Skretting Aquaculture Innovation (AI), Stavanger, Norway
| | | | - Charles McGurk
- Skretting Aquaculture Innovation (AI), Stavanger, Norway
| | - Espen Rimstad
- grid.19477.3c0000 0004 0607 975XUnit of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433 Ås, Norway
| | - Øystein Wessel
- grid.19477.3c0000 0004 0607 975XUnit of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433 Ås, Norway
| | - Erling Olaf Koppang
- grid.19477.3c0000 0004 0607 975XUnit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433 Ås, Norway
| | - Håvard Bjørgen
- grid.19477.3c0000 0004 0607 975XUnit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433 Ås, Norway
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Thorarinsson R, Wolf JC, Inami M, Sindre H, Skjerve E, Evensen Ø, Rimstad E. Effects of a DNA and multivalent oil-adjuvanted vaccines against pancreas disease in Atlantic salmon (Salmo salar) challenged with salmonid alphavirus subtype 3. Fish and Shellfish Immunology Reports 2022; 3:100063. [PMID: 36419608 PMCID: PMC9680106 DOI: 10.1016/j.fsirep.2022.100063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 08/08/2022] [Accepted: 08/09/2022] [Indexed: 12/03/2022] Open
Abstract
Efficacy of a DNA- and conventional vaccines against pancreas disease is compared. Higher neutralization antibody levels in the DNA vaccine group compared to controls. Significantly lower viremia levels in the DNA vaccine group than the controls. Efficacy against disease-induced growth loss and damage in target organs is shown . Mortality levels low and not significantly different from the control group.
Salmonid alphavirus (SAV) causes pancreas disease (PD) in Atlantic salmon (Salmo salar). In seawater-farmed salmonids in the southern part of Norway SAV subtype 3 (SAV3) is dominating. PD continues to cause significant economic and fish health concerns in this region despite years of extensive use of oil-adjuvanted vaccines (OAVs) containing inactivated whole virus (IWV) antigens. In the current study, three commercially available PD vaccines were tested. Group A got a DNA vaccine (DNAV) injected intramuscularly (i.m.) plus an OAV without a PD component injected intraperitoneally (i.p.). Groups B and C got different OAV IWV vaccines injected i.p., respectively. The control group was i.p. injected with saline. Approximately 12 weeks after vaccination, the post smolt groups were challenged in seawater with SAV3 by cohabitation. Samples were collected pre-challenge, and at 19, 54 and 83 days post-challenge (dpc). There were no differences in growth or visible intraperitoneal side effects between the immunized groups prior to challenge. Fish in group A had significantly higher SAV3 neutralizing antibody titers than the other groups pre-challenge and significantly lower SAV3 viremia levels than the control group at 19 dpc. Fish in group A had significantly more weight gain than the other groups measured at 54 and 83 dpc. Prevalence and severity of heart necrosis at 19 dpc and loss of exocrine pancreas tissue at 54 and 83 dpc were significantly lower in groups A and B compared to group C and controls. The cumulative mortality in the control group during the challenge period was 10.5%. Group A experienced the lowest mortality (6.4%) albeit not statistically different from the controls. The results suggest that DNAV may reduce the clinical and economic impact of PD by improved protection against SAV3-induced changes in pancreas tissue and growth impairment.
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Aunsmo A, Martinsen L, Bruheim T, Sekkelsten-Kindt MM, Sandtrø A, Gaasø S, Braaen S, Rimstad E. Triploid Atlantic salmon (Salmo salar) may have increased risk of primary field outbreaks of infectious salmon anaemia. J Fish Dis 2022; 45:1733-1743. [PMID: 35914108 PMCID: PMC9805046 DOI: 10.1111/jfd.13695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 07/17/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
The impact that escaped farmed fish may have on wild populations is of major concern for Atlantic salmon (Salmo salar) farming. Triploid fish, being infertile, were originally introduced to mitigate the genetic impact of escaped fish. In the recent years, an increase in the number of infectious salmon anaemia (ISA) outbreaks in Norway has been observed, mainly in the northern parts, which is also where farming of triploid fish has been licensed. The present study investigated the susceptibility of triploid Atlantic salmon to ISA both by field observations and experimental infections. Based on field observations, we found an increased susceptibility, with 9.4 increased odds to primary ISA outbreaks in triploid fish versus diploid fish at production-site level, and a tendency of increased odds (3.4) of ISA in triploid fish at individual cage level at sited with primary outbreaks. At some sites, ISA outbreaks were only diagnosed in cages with triploid fish and not in cages with diploid fish. Primary ISA outbreaks are the source for further spread of the disease, and it is noteworthy that in an experimental trial we found significantly more viral RNA in non-ISA-vaccinated triploid than in non-ISA-vaccinated diploid fish at the peak of the infection. Interestingly, the notable differences of susceptibility to ISA for non-ISA vaccinated diploid and triploid fish observed in field were not repeated experimentally. The possible increased risk of ISA should be considered when evaluating the costs and benefits of triploid salmon in farming. It is recommended to keep triploid and diploid fish in biosecure separated sites, or that triploid fish are not farmed at all.
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Affiliation(s)
- Arnfinn Aunsmo
- Department of Production Animal Clinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
- Laxar Fiskeldi, Reykjavik, Iceland
| | | | | | | | - Ane Sandtrø
- PHARMAQ, Skogmo Industriområde, Overhalla, Norway
| | | | - Stine Braaen
- Department of Paraclinical Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Espen Rimstad
- Department of Paraclinical Sciences, Norwegian University of Life Sciences, Ås, Norway
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12
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Ortega-Villaizan MDM, Coll J, Rimstad E. Editorial: The role of red blood cells in the immune response of fish. Front Immunol 2022; 13:1005546. [PMID: 36148226 PMCID: PMC9489223 DOI: 10.3389/fimmu.2022.1005546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 08/09/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Maria del Mar Ortega-Villaizan
- Departamento de Bioquímica y Biología Molecular, Instituto de Biología Molecular y Celular (IBMC), Universidad Miguel Hernández (UMH), Elche, Spain
- Departamento de Bioquímica y Biología Molecular, Instituto de Investigación, Desarrollo e Innovación en Biotecnologîa Sanitaria de Elche (IDiBE), Universidad Miguel Hernández (UMH), Elche, Spain
- *Correspondence: Maria del Mar Ortega-Villaizan,
| | - Julio Coll
- Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
| | - Espen Rimstad
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
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13
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Vatne NA, Stormoen M, Lund M, Devold M, Rimstad E, Wessel Ø. Genetic grouping and geographic distribution of Piscine orthoreovirus-1 (PRV-1) in farmed Atlantic salmon in Norway. Vet Res 2021; 52:131. [PMID: 34649601 PMCID: PMC8515743 DOI: 10.1186/s13567-021-01000-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 09/10/2021] [Indexed: 11/29/2022] Open
Abstract
Piscine orthoreovirus-1 (PRV-1) is the causative agent of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar). However, it has been shown that PRV-1 variants differ in their ability to induce HSMI. The objective of this work was to identify the PRV-1 variants in Norwegian aquaculture and their geographical distribution. Sequencing and subsequent analysis of the five genomic segments (S1, S4, M2, L1 and L2) putatively linked to virulence, made out the basis of the study. Thirty-seven Norwegian PRV-1 isolates were sequenced, and they grouped into eight genogroups based on combinations of the five analyzed genomic segments. Two groups were defined as high-virulent and two low-virulent, based on comparison with PRV-1 reference isolates with known virulence. The remaining four groups were of unknown virulence. The geographic distribution indicated a higher frequency of the high-virulent isolates in the mid- and northern regions. The present study confirms circulation of both high- and low-virulent isolates of PRV-1 in farmed Atlantic salmon in Norway. To reduce the impact of PRV-1 related disease, detection and differentiation between high- and low-virulent genogroups of PRV-1 could be a targeted approach for reduction of high-virulent variants.
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Affiliation(s)
- Nina A Vatne
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433, Ås, Norway
| | - Marit Stormoen
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433, Ås, Norway
| | | | | | - Espen Rimstad
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433, Ås, Norway
| | - Øystein Wessel
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433, Ås, Norway.
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14
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Malik MS, Nyman IB, Wessel Ø, Dahle MK, Rimstad E. Dynamics of Polarized Macrophages and Activated CD8 + Cells in Heart Tissue of Atlantic Salmon Infected With Piscine Orthoreovirus-1. Front Immunol 2021; 12:729017. [PMID: 34603301 PMCID: PMC8481380 DOI: 10.3389/fimmu.2021.729017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/31/2021] [Indexed: 11/13/2022] Open
Abstract
Piscine orthoreovirus (PRV-1) infection causes heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar). The virus is also associated with focal melanized changes in white skeletal muscle where PRV-1 infection of macrophages appears to be important. In this study, we studied the macrophage polarization into M1 (pro-inflammatory) and M2 (anti-inflammatory) phenotypes during experimentally induced HSMI. The immune response in heart with HSMI lesions was characterized by CD8+ and MHC-I expressing cells and not by polarized macrophages. Fluorescent in situ hybridization (FISH) assays revealed localization of PRV-1 in a few M1 macrophages in both heart and skeletal muscle. M2 type macrophages were widely scattered in the heart and were more abundant in heart compared to the skeletal muscle. However, the M2 macrophages did not co-stain for PRV-1. There was a strong cellular immune response to the infection in the heart compared to that of the skeletal muscle, seen as increased MHC-I expression, partly in cells also containing PRV-1 RNA, and a high number of cytotoxic CD8+ granzyme producing cells that targeted PRV-1. In skeletal muscle, MHC-I expressing cells and CD8+ cells were dispersed between myocytes, but these cells did not stain for PRV-1. Gene expression analysis by RT-qPCR complied with the FISH results and confirmed a drop in level of PRV-1 following the cell mediated immune response. Overall, the results indicated that M1 macrophages do not contribute to the initial development of HSMI. However, large numbers of M2 macrophages reside in the heart and may contribute to the subsequent fast recovery following clearance of PRV-1 infection.
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Affiliation(s)
- Muhammad Salman Malik
- Section of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Ingvild Berg Nyman
- Section of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Øystein Wessel
- Section of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Maria K Dahle
- Department of Fish Health, Norwegian Veterinary Institute, Ås, Norway
| | - Espen Rimstad
- Section of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
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15
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Aksnes I, Braaen S, Markussen T, Åkesson CP, Villoing S, Rimstad E. Genetically modified attenuated salmonid alphavirus: A potential strategy for immunization of Atlantic salmon. J Fish Dis 2021; 44:923-937. [PMID: 33591590 DOI: 10.1111/jfd.13352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 01/29/2021] [Accepted: 01/31/2021] [Indexed: 06/12/2023]
Abstract
Pancreas disease (PD) is a serious challenge in European salmonid aquaculture caused by salmonid alphavirus (SAV). In this study, we report the effect of immunization of Atlantic salmon with three attenuated infectious SAV3 strains with targeted mutations in a glycosylation site of the envelope E2 protein and/or in a nuclear localization signal in the capsid protein. In a pilot experiment, it was shown that the mutated viral strains replicated in fish, transmitted to naïve cohabitants and that the transmission had not altered the sequences. In the main experiment, the fish were immunized with the strains and challenged with SAV3 eight weeks after immunization. Immunization resulted in infection both in injected fish and 2 weeks later in the cohabitant fish, followed by a persistent but declining load of the mutated virus variants in the hearts. The immunized fish developed clinical signs and pathology consistent with PD prior to challenge. However, fish injected with the virus mutated in both E2 and capsid showed little clinical signs and had higher average weight gain than the groups immunized with the single mutated variants. The SAV strain used for challenge was not detected in the immunized fish indicating that these fish were protected against superinfection with SAV during the 12 weeks of the experiment.
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Affiliation(s)
- Ida Aksnes
- Department of Paraclinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | - Stine Braaen
- Department of Paraclinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | - Turhan Markussen
- Department of Paraclinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | | | | | - Espen Rimstad
- Department of Paraclinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
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16
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Thorarinsson R, Wolf JC, Inami M, Phillips L, Jones G, Macdonald AM, Rodriguez JF, Sindre H, Skjerve E, Rimstad E, Evensen Ø. Effect of a novel DNA vaccine against pancreas disease caused by salmonid alphavirus subtype 3 in Atlantic salmon (Salmo salar). Fish Shellfish Immunol 2021; 108:116-126. [PMID: 33285168 DOI: 10.1016/j.fsi.2020.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 09/29/2020] [Accepted: 12/01/2020] [Indexed: 05/13/2023]
Abstract
Pancreas disease (PD) caused by salmonid alphavirus subtype 3 (SAV3) is a serious disease with large economic impact on farmed Norwegian Atlantic salmon production despite years of use of oil-adjuvanted vaccines against PD (OAVs). In this study, two commercially available PD vaccines, a DNA vaccine (DNAV) and an OAV, were compared in an experimental setting. At approximately 1040° days (dd) at 12 °C post immunization, the fish were challenged with SAV3 by cohabitation 9 days after transfer to sea water. Sampling was done prior to challenge and at 19, 54, and 83 days post-challenge (dpc). When compared to the OAV and control (Saline) groups, the DNAV group had significantly higher SAV3 neutralizing antibody titers after the immunization period, significantly lower SAV3 viremia levels at 19 dpc, significantly reduced transmission of SAV3 to naïve fish in the latter part of the viremic phase, significantly higher weight gain post-challenge, and significantly reduced prevalence and/or severity of SAV-induced morphologic changes in target organs. The DNAV group had also significantly higher post-challenge survival compared to the Saline group, but not to the OAV group. The data suggest that use of DNAV may reduce the economic impact of PD by protecting against destruction of the pancreas tissue and subsequent growth impairment which is the most common and costly clinical outcome of this disease.
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Affiliation(s)
| | - Jeffrey C Wolf
- Experimental Pathology Laboratories Inc., 45600 Terminal Drive, Sterling, VA, 20166, USA.
| | - Makoto Inami
- VESO Vikan, Beisvågveien 108, Vikan, N-7810, Namsos, Norway.
| | - Lisa Phillips
- Elanco Canada Ltd., 37 McCarville Street, Charlottetown, PE C1E 2A7, Canada.
| | - Ginny Jones
- Elanco Canada Ltd., 37 McCarville Street, Charlottetown, PE C1E 2A7, Canada.
| | - Alicia M Macdonald
- Elanco Canada Ltd., 37 McCarville Street, Charlottetown, PE C1E 2A7, Canada.
| | - Jose F Rodriguez
- Elanco Canada Ltd., 37 McCarville Street, Charlottetown, PE C1E 2A7, Canada.
| | - Hilde Sindre
- Norwegian Veterinary Institute, Ullevålsveien 68, N-0454, Oslo, Norway.
| | - Eystein Skjerve
- Norwegian University of Life Sciences, School of Veterinary Medicine, Ullevålsveien 72, N-0454, Oslo, Norway.
| | - Espen Rimstad
- Norwegian University of Life Sciences, School of Veterinary Medicine, Ullevålsveien 72, N-0454, Oslo, Norway.
| | - Øystein Evensen
- Norwegian University of Life Sciences, School of Veterinary Medicine, Ullevålsveien 72, N-0454, Oslo, Norway.
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17
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Malik MS, Bjørgen H, Nyman IB, Wessel Ø, Koppang EO, Dahle MK, Rimstad E. PRV-1 Infected Macrophages in Melanized Focal Changes in White Muscle of Atlantic Salmon ( Salmo salar) Correlates With a Pro-Inflammatory Environment. Front Immunol 2021; 12:664624. [PMID: 33995395 PMCID: PMC8116804 DOI: 10.3389/fimmu.2021.664624] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 04/13/2021] [Indexed: 12/27/2022] Open
Abstract
Melanized focal changes in white skeletal muscle of farmed Atlantic salmon, "black spots", is a quality problem affecting on average 20% of slaughtered fish. The spots appear initially as "red spots" characterized by hemorrhages and acute inflammation and progress into black spots characterized by chronic inflammation and abundant pigmented cells. Piscine orthoreovirus 1 (PRV-1) was previously found to be associated with macrophages and melano-macrophages in red and black spots. Here we have addressed the inflammatory microenvironment of red and black spots by studying the polarization status of the macrophages and cell mediated immune responses in spots, in both PRV-1 infected and non-infected fish. Samples that had been collected at regular intervals through the seawater production phase in a commercial farm were analyzed by multiplex fluorescent in situ hybridization (FISH) and RT-qPCR methods. Detection of abundant inducible nitric oxide synthase (iNOS2) expressing M1-polarized macrophages in red spots demonstrated a pro-inflammatory microenvironment. There was an almost perfect co-localization with the iNOS2 expression and PRV-1 infection. Black spots, on the other side, had few iNOS2 expressing cells, but a relatively high number of arginase-2 expressing anti-inflammatory M2-polarized macrophages containing melanin. The numerous M2-polarized melano-macrophages in black spots indicate an ongoing healing phase. Co-localization of PRV-1 and cells expressing CD8+ and MHC-I suggests a targeted immune response taking place in the spots. Altogether, this study indicates that PRV-1 induces a pro-inflammatory environment that is important for the pathogenesis of the spots. We do not have indication that infection of PRV-1 is the initial causative agent of this condition.
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Affiliation(s)
- Muhammad Salman Malik
- Section of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Håvard Bjørgen
- Section of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Ingvild Berg Nyman
- Section of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Øystein Wessel
- Section of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Erling Olaf Koppang
- Section of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Maria K. Dahle
- Department of Fish Health, Norwegian Veterinary Institute, Oslo, Norway
| | - Espen Rimstad
- Section of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
- *Correspondence: Espen Rimstad,
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18
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Teige LH, Aksnes I, Røsæg MV, Jensen I, Jørgensen J, Sindre H, Collins C, Collet B, Rimstad E, Dahle MK, Boysen P. Detection of specific Atlantic salmon antibodies against salmonid alphavirus using a bead-based immunoassay. Fish Shellfish Immunol 2020; 106:374-383. [PMID: 32738513 DOI: 10.1016/j.fsi.2020.07.055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/20/2020] [Accepted: 07/24/2020] [Indexed: 06/11/2023]
Abstract
Salmonid alphavirus (SAV) is the etiological cause of pancreas disease (PD) in Atlantic salmon (Salmo salar). Several vaccines against SAV are in use, but PD still cause significant mortality and concern in European aquaculture, raising the need for optimal tools to monitor SAV immunity. To monitor and control the distribution of PD in Norway, all salmonid farms are regularly screened for SAV by RT-qPCR. While the direct detection of SAV is helpful in the early stages of infection, serological methods could bring additional information on acquired SAV immunity in the later stages. Traditionally, SAV antibodies are monitored in neutralization assays, but they are time-consuming and cumbersome, thus alternative assays are warranted. Enzyme-linked immunosorbent assays (ELISAs) have not yet been successfully used for anti-SAV antibody detection in aquaculture. We aimed to develop a bead-based immunoassay for SAV-specific antibodies. By using detergent-treated SAV particles as antigens, we detected SAV-specific antibodies in plasma collected from both a SAV challenge trial and a field outbreak of PD. Increased levels of SAV-specific antibodies were seen after most fish had become negative for viral RNA. The bead-based assay is time saving compared to virus neutralization assays, and suitable for non-lethal testing due to low sample size requirements. We conclude that the bead-based immunoassay for SAV antibody detection is a promising diagnostic tool to complement SAV screening in aquaculture.
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Affiliation(s)
- Lena Hammerlund Teige
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Oslo, Norway
| | - Ida Aksnes
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Oslo, Norway
| | | | - Ingvill Jensen
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, Tromsø, Norway
| | - Jorunn Jørgensen
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, Tromsø, Norway
| | - Hilde Sindre
- Department of Fish Health, Norwegian Veterinary Institute, Oslo, Norway
| | - Catherine Collins
- Université Paris-Saclay, INRAE, UVSQ, VIM, 78350, Jouy-en-Josas, France
| | - Bertrand Collet
- Université Paris-Saclay, INRAE, UVSQ, VIM, 78350, Jouy-en-Josas, France
| | - Espen Rimstad
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Oslo, Norway
| | - Maria K Dahle
- The Norwegian College of Fishery Science, UiT The Arctic University of Norway, Tromsø, Norway; Department of Fish Health, Norwegian Veterinary Institute, Oslo, Norway
| | - Preben Boysen
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Oslo, Norway.
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19
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Aksnes I, Markussen T, Braaen S, Rimstad E. Mutation of N-glycosylation Sites in Salmonid Alphavirus (SAV) Envelope Proteins Attenuate the Virus in Cell Culture. Viruses 2020; 12:v12101071. [PMID: 32987930 PMCID: PMC7650630 DOI: 10.3390/v12101071] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/18/2020] [Accepted: 09/21/2020] [Indexed: 12/16/2022] Open
Abstract
Salmonid alphavirus (SAV) is the cause of pancreas disease and sleeping disease in farmed salmonid fish in Europe. The spread of these diseases has been difficult to control with biosecurity and current vaccination strategies, and increased understanding of the viral pathogenesis could be beneficial for the development of novel vaccine strategies. N-glycosylation of viral envelope proteins may be crucial for viral virulence and a possible target for its purposed attenuation. In this study, we mutated the N-glycosylation consensus motifs of the E1 and E2 glycoproteins of a SAV3 infectious clone using site-directed mutagenesis. Mutation of the glycosylation motif in E1 gave a complete inactivation of the virus as no viral replication could be detected in cell culture and infectious particles could not be rescued. In contrast, infectious virus particles could be recovered from the SAV3 E2 mutants (E2319Q, E2319A), but not if they were accompanied by lack of N-glycosylation in E1. Compared to the non-mutated infectious clone, the SAV3-E2319Q and SAV3-E2319A recombinant viruses produced less cytopathic effects in cell culture and lower amounts of infectious viral particles. In conclusion, the substitution in the N-linked glycosylation site in E2 attenuated SAV3 in cell culture. The findings could be useful for immunization strategies using live attenuated vaccines and testing in fish will be desirable to study the clone’s properties in vivo.
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20
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Wessel Ø, Hansen EF, Løvoll M, Inami M, Husby A, Kruse G, Dahle MK, Rimstad E. Inactivation of Piscine orthoreovirus. J Fish Dis 2020; 43:1039-1048. [PMID: 32632958 DOI: 10.1111/jfd.13214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/10/2020] [Accepted: 06/12/2020] [Indexed: 06/11/2023]
Abstract
Piscine orthoreovirus infects various salmonid fish species, and the infection is associated with diseases such as heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar). There are no vaccines available or genetically selected resistant hosts that can efficiently control piscine orthoreovirus (PRV) infection. Currently, the only prophylactic measure against PRV is general biosecurity measures aiming to break the transmission cycle. Methods to eradicate infectious virus from contaminated facilities are desirable, but the knowledge on how to inactivate PRV is lacking. A major bottleneck for inactivation studies is the lack of ability to propagate PRV in cell culture. Therefore, in this study we developed an in vivo model for detection of infectious PRV particles after treatment of the virus with inactivation tools such as heat, pH, iodine, UV and commercially available disinfectants. The results show that standard iodine treatment is efficient in inactivation of the virus, and similarly are high and low pH extremes and treatment with Virocid, a commercially available disinfectant. A UV dose of at least 50 mJ/cm2 is required for inactivation, and the virus has high resistance against heat treatment.
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Affiliation(s)
- Øystein Wessel
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Elisabeth F Hansen
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | | | | | | | | | | | - Espen Rimstad
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
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21
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Bjoergen H, Malik MS, Rimstad E, Koppang EO. Inflammatory reactions and melanogenesis in salmon during virus infection. The Journal of Immunology 2020. [DOI: 10.4049/jimmunol.204.supp.92.32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Melanised skeletal muscle changes (black spots) are a serious problem for the salmon industry world-wide, causing extensive production losses. Piscine orthoreovirus (PRV) is associated with the condition. The initial cause for the focal changes remains obscure. Early changes start as muscle bleedings and extensive muscle necrosis, and so far, these changes cannot be explained, However, from this acute phase, the changes may progress into melanised focal changes appearing as chronic granulomatous reactions. Granulomatous melanised changes have been consistently observed in PRV infected fish, and in serious changes, the tissue persistence of virus dominate the changes despite the inflammatory changes. Here, we address the pathogenesis of PRV infection and phases of melanised focal changes development. Fluorescent in situ hybridisation (FISH) assay confirmed the colocalisation of iNOS2 transcripts (M1 activated macrophages) with PRV in red spot whereas both M1 and M2 (Arg2 transcripts) macrophages localized at PRV infected clusters in black spots. Melano-macrophages were found positive with Arg2 transcripts demonstrating their role in tissue repair mechanism. In PRV negative fish low expression of M1 and M2 specific transcripts suggest PRV act as an accelerator for the melanisation in these focal changes. Transcripts specific for melanin production were observed in non-melanised cells in early stages of the condition and in melano-macrophages in late stages. The nature of the melano-macrophages is disputed and the rationale for their melanin production is not understood. Our investigations reveal new characteristics both of the pathogenesis of focal melanised changes as well as of the melano-macrophages involved.
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Affiliation(s)
- Haavard Bjoergen
- 1Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Norway
| | | | - Espen Rimstad
- 1Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Norway
| | - Erling Olaf Koppang
- 1Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Norway
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22
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Bjørgen H, Kumar S, Gunnes G, Press CM, Rimstad E, Koppang EO. Immunopathological characterization of red focal changes in Atlantic salmon (Salmo salar) white muscle. Vet Immunol Immunopathol 2020; 222:110035. [PMID: 32200172 DOI: 10.1016/j.vetimm.2020.110035] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 02/26/2020] [Accepted: 03/06/2020] [Indexed: 11/18/2022]
Abstract
Farmed Atlantic salmon (Salmo salar) are prone to various conditions affecting the quality of the fillet. A well-known but so far poorly understood condition is the focal red changes in muscle, often referred to as haemorrhages. Such changes are characterized by muscle necrosis, haemorrhages and acute inflammation. They can progress into focal melanised changes, a chronic inflammatory condition with melanin-producing leukocytes. The initial cause of intramuscular haemorrhages is unknown. In this study, we aimed to reveal some of their key immunological features. Samples of red focal changes were investigated by immunohistochemistry (IHC), in situ hybridization (ISH) and RT-qPCR for various immune markers. The results were compared with samples of melanised changes and control muscle, subjected to the same analyses. In all red changes, infiltrates with mononuclear cells were detected, consisting mostly of MHC class I/II+ cells, but also of CD3+ and CD8+ cells. ISH studies on IgM showed few to moderate amounts of B-cells in red focal changes. Trends in the RT-qPCR showed upregulation of genes related to innate immunity in the red changes, whereas genes related to adaptive immunity were upregulated in the melanised changes. An important result was the significant downregulation of the anti-inflammatory cytokine IL10 in all red changes. Our findings indicate that we can rule out an auto invasive nature of the changes. The downregulation of IL10 at an early phase is a trait for the condition.
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Affiliation(s)
- Håvard Bjørgen
- Department of Basic Science and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway.
| | - Subramani Kumar
- Centre for Biotechnology, Anna University, Chennai, 600 025, India.
| | - Gjermund Gunnes
- Department of Basic Science and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway.
| | - Charles McL Press
- Department of Basic Science and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway.
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway.
| | - Erling Olaf Koppang
- Department of Basic Science and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway.
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23
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Rimstad E, Markussen T. Infectious salmon anaemia virus-molecular biology and pathogenesis of the infection. J Appl Microbiol 2020; 129:85-97. [PMID: 31885186 DOI: 10.1111/jam.14567] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 11/29/2022]
Abstract
Aquaculture has a long history in many parts of the world, but it is still young at an industrial scale. Marine fish farming in open nets of a single fish species at high densities compared to their wild compatriots opens a plethora of possible infections. Infectious salmon anaemia (ISA) is an example of disease that surfaced after large-scale farming of Atlantic salmon (Salmo salar) appeared. Here, a review of the molecular biology of the ISA virus (ISAV) with emphasis on its pathogenicity is presented. The avirulent HPR0 variant of ISAV has resisted propagation in cell cultures, which has restricted the ability to perform in vivo experiments with this variant. The transition from avirulent HPR0 to virulent HPRΔ has not been methodically studied under controlled experimental conditions, and the triggers of the transition from avirulent to virulent forms have not been mapped. Genetic segment reassortment, recombination and mutations are important mechanisms in ISAV evolution, and for the development of virulence. In the 25 years since the ISAV was identified, large amounts of sequence data have been collected for epidemiologic and transmission studies, however, the lack of good experimental models for HPR0 make the risk evaluation of the presence of this avirulent, ubiquitous variant uncertain. This review summarizes the current knowledge related to molecular biology and pathogenicity of this important aquatic orthomyxovirus.
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Affiliation(s)
- E Rimstad
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - T Markussen
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
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24
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Teige LH, Kumar S, Johansen GM, Wessel Ø, Vendramin N, Lund M, Rimstad E, Boysen P, Dahle MK. Detection of Salmonid IgM Specific to the Piscine Orthoreovirus Outer Capsid Spike Protein Sigma 1 Using Lipid-Modified Antigens in a Bead-Based Antibody Detection Assay. Front Immunol 2019; 10:2119. [PMID: 31552049 PMCID: PMC6743345 DOI: 10.3389/fimmu.2019.02119] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 08/22/2019] [Indexed: 11/13/2022] Open
Abstract
Bead-based multiplex immunoassays are promising tools for determination of the specific humoral immune response. In this study, we developed a multiplexed bead-based immunoassay for the detection of Atlantic salmon (Salmo salar) antibodies against Piscine orthoreovirus (PRV). Three different genotypes of PRV (PRV-1, PRV-2, and PRV-3) cause disease in farmed salmonids. The PRV outer capsid spike protein σ1 is predicted to be a host receptor binding protein and a target for neutralizing and protective antibodies. While recombinant σ1 performed poorly as an antigen to detect specific antibodies, N-terminal lipid modification of recombinant PRV-1 σ1 enabled sensitive detection of specific IgM in the bead-based assay. The specificity of anti-PRV-1 σ1 antibodies was confirmed by western blotting and pre-adsorption of plasma. Binding of non-specific IgM to beads coated with control antigens also increased after PRV infection, indicating a release of polyreactive antibodies. This non-specific binding was reduced by heat treatment of plasma. The same immunoassay also detected anti-PRV-3 σ1 antibodies from infected rainbow trout. In summary, a refined bead based immunoassay created by N-terminal lipid-modification of the PRV-1 σ1 antigen allowed sensitive detection of anti-PRV-1 and anti-PRV-3 antibodies from salmonids.
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Affiliation(s)
- Lena Hammerlund Teige
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Subramani Kumar
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway.,Stem Cell and Cancer Biology Lab, Centre for Biotechnology, Anna University, Chennai, India
| | - Grethe M Johansen
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Øystein Wessel
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Niccolò Vendramin
- National Institute of Aquatic Resources, Technical University of Denmark, Lyngby, Denmark
| | - Morten Lund
- Department of Fish Health, Norwegian Veterinary Institute, Oslo, Norway.,PatoGen, Alesund, Norway
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Preben Boysen
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Maria K Dahle
- Department of Fish Health, Norwegian Veterinary Institute, Oslo, Norway
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25
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Malik MS, Bjørgen H, Dhamotharan K, Wessel Ø, Koppang EO, Di Cicco E, Hansen EF, Dahle MK, Rimstad E. Erythroid Progenitor Cells in Atlantic Salmon ( Salmo salar) May Be Persistently and Productively Infected with Piscine Orthoreovirus (PRV). Viruses 2019; 11:E824. [PMID: 31491892 PMCID: PMC6784031 DOI: 10.3390/v11090824] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/30/2019] [Accepted: 09/03/2019] [Indexed: 12/13/2022] Open
Abstract
Piscine orthoreovirus (PRV-1) can cause heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar). The virus targets erythrocytes in the acute peak phase, followed by cardiomyocytes, before the infection subsides into persistence. The persistent phase is characterized by high level of viral RNA, but low level of viral protein. The origin and nature of persistent PRV-1 are not clear. Here, we analyzed for viral persistence and activity in various tissues and cell types in experimentally infected Atlantic salmon. Plasma contained PRV-1 genomic dsRNA throughout an 18-week long infection trial, indicating that viral particles are continuously produced and released. The highest level of PRV-1 RNA in the persistent phase was found in kidney. The level of PRV-1 ssRNA transcripts in kidney was significantly higher than that of blood cells in the persistent phase. In-situ hybridization assays confirmed that PRV-1 RNA was present in erythroid progenitor cells, erythrocytes, macrophages, melano-macrophages and in some additional un-characterized cells in kidney. These results show that PRV-1 establishes a productive, persistent infection in Atlantic salmon and that erythrocyte progenitor cells are PRV target cells.
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Affiliation(s)
- Muhammad Salman Malik
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
| | - Håvard Bjørgen
- Department of Basic Science and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
| | - Kannimuthu Dhamotharan
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
| | - Øystein Wessel
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
| | - Erling Olaf Koppang
- Department of Basic Science and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
| | - Emiliano Di Cicco
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7, Canada.
| | - Elisabeth F Hansen
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
| | - Maria K Dahle
- Department of Fish Health, Norwegian Veterinary Institute, 0454 Oslo, Norway
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
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26
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Vendramin N, Cuenca A, Sørensen J, Alencar ALF, Christiansen DH, Jacobsen JA, Axen C, Lieffrig F, Ruane NM, Martin P, Sheehan T, Iburg TM, Rimstad E, Olesen NJ. Presence and genetic variability of Piscine orthoreovirus genotype 1 (PRV-1) in wild salmonids in Northern Europe and North Atlantic Ocean. J Fish Dis 2019; 42:1107-1118. [PMID: 31140193 DOI: 10.1111/jfd.13025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 04/11/2019] [Accepted: 04/14/2019] [Indexed: 06/09/2023]
Abstract
Piscine orthoreovirus genotype 1 (PRV-1) is widespread in farmed Atlantic salmon (Salmo salar L.) populations in northern Europe, Canada and Chile. PRV-1 occurs in wild fish in Norway and Canada; however, little information of its geographical distribution in wild populations is currently available, and the effect of PRV-1 infection in wild populations is currently unknown. In this study, we present the findings of a survey conducted on 1,130 wild salmonids sampled in Denmark, Sweden, Ireland, Faroe Islands, France, Belgium and Greenland between 2008 and 2017. PRV-1 is reported for the first time in wild salmonids in Denmark, Sweden, Faroe Island and Ireland. The annual PRV-1 prevalence ranged from 0% in France, Belgium and Greenland to 43% in Faroe Islands. In total, 66 samples tested positive for PRV-1, including Atlantic salmon broodfish returning to spawn and Atlantic salmon collected at the feeding ground north of Faroe Islands. The phylogenetic analysis of S1 sequences of the PRV-1 isolates obtained in this survey did not show systematic geographical distribution. This study sheds light on the spread and genetic diversity of the virus identified in populations of free-living fish and provides rationale for screening wild broodfish used in restocking programmes.
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Affiliation(s)
- Niccoló Vendramin
- National Institute of Aquatic Resources, Technical University of Denmark, Lyngby, Denmark
| | - Argelia Cuenca
- National Institute of Aquatic Resources, Technical University of Denmark, Lyngby, Denmark
| | - Juliane Sørensen
- National Institute of Aquatic Resources, Technical University of Denmark, Lyngby, Denmark
| | - Anna L F Alencar
- National Institute of Aquatic Resources, Technical University of Denmark, Lyngby, Denmark
| | - Debes H Christiansen
- National Reference Laboratory for fish diseases, Faroese Food and Veterinary Authority (FFVA), Torshavn, Faroe Islands
| | - Jan A Jacobsen
- Havstovan Faroe Marine Research Institute (FAMRI), Torshavn, Faroe Islands
| | - Charlotte Axen
- Swedish National Veterinary Institute (SVA), Uppsala, Sweden
| | | | - Neil M Ruane
- Fish Health Unit, Marine Institute, Galway, Ireland
| | | | - Timothy Sheehan
- Northeast Fisheries Science Center, National Marine Fisheries Service, Woods Hole, Massachusetts
| | - Tine M Iburg
- National Institute of Aquatic Resources, Technical University of Denmark, Lyngby, Denmark
| | | | - Niels J Olesen
- National Institute of Aquatic Resources, Technical University of Denmark, Lyngby, Denmark
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27
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Bjørgen H, Haldorsen R, Oaland Ø, Kvellestad A, Kannimuthu D, Rimstad E, Koppang EO. Melanized focal changes in skeletal muscle in farmed Atlantic salmon after natural infection with Piscine orthoreovirus (PRV). J Fish Dis 2019; 42:935-945. [PMID: 30972792 PMCID: PMC6850454 DOI: 10.1111/jfd.12995] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/05/2019] [Accepted: 03/06/2019] [Indexed: 06/09/2023]
Abstract
Melanized focal changes in skeletal muscle of farmed Atlantic salmon (Salmo salar) are a major quality problem. The aetiology is unknown, but infection with Piscine orthoreovirus (PRV) has been associated with the condition. Here, we addressed the pathogenesis of red and melanized focal changes and their association with PRV. First, a population of farmed fish (PRV-negative prior to sea transfer) was sequentially investigated throughout the seawater period. The fish were autopsied and tested for PRV infection. Muscular changes were described by macroscopy and histology, and a classification system was established. Second, in an experimental infection trial, PRV was injected intramuscularly to induce changes. The farmed fish was gradually infected with PRV. Red focal changes occurred throughout the observation period with a low prevalence regardless of PRV status. Melanized changes were highly diverse and their prevalence increased during the trial. Changes of low macroscopic grade and histological category were more prevalent in PRV-negative fish. Diffuse granulomatous melanized changes only occurred after PRV infection. No muscular changes were observed in the experimentally challenged fish. Our studies do not indicate that PRV infection causes red focal changes, but seems important in the development of granulomatous melanized changes.
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Affiliation(s)
- Håvard Bjørgen
- Institute of Basic Science and Aquatic Medicine, Faculty of Veterinary MedicineNorwegian University of Life SciencesOsloNorway
| | | | | | - Agnar Kvellestad
- Institute of Basic Science and Aquatic Medicine, Faculty of Veterinary MedicineNorwegian University of Life SciencesOsloNorway
| | - Dhamotharan Kannimuthu
- Institute of Food Safety and Infection Biology, Faculty of Veterinary MedicineNorwegian University of Life SciencesOsloNorway
| | - Espen Rimstad
- Institute of Food Safety and Infection Biology, Faculty of Veterinary MedicineNorwegian University of Life SciencesOsloNorway
| | - Erling Olaf Koppang
- Institute of Basic Science and Aquatic Medicine, Faculty of Veterinary MedicineNorwegian University of Life SciencesOsloNorway
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28
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Vendramin N, Kannimuthu D, Olsen AB, Cuenca A, Teige LH, Wessel Ø, Iburg TM, Dahle MK, Rimstad E, Olesen NJ. Piscine orthoreovirus subtype 3 (PRV-3) causes heart inflammation in rainbow trout (Oncorhynchus mykiss). Vet Res 2019; 50:14. [PMID: 30777130 PMCID: PMC6380033 DOI: 10.1186/s13567-019-0632-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 01/03/2019] [Indexed: 12/31/2022] Open
Abstract
Piscine orthoreovirus (PRV) mediated diseases have emerged throughout salmonid aquaculture. Three PRV subtypes are currently reported as causative agents of or in association with diseases in different salmonid species. PRV-1 causes heart and skeletal muscle inflammation (HSMI) in Atlantic salmon (Salmo salar) and is associated with jaundice syndrome in farmed chinook salmon (Oncorhynchus tshawytscha). PRV-2 causes erythrocytic inclusion body syndrome (EIBS) in coho salmon in Japan. PRV-3 has recently been associated with a disease in rainbow trout (Oncorhynchus mykiss) characterized by anaemia, heart and red muscle pathology; to jaundice syndrome in coho salmon (Oncorhynchus kisutch). In this study, we conducted a 10-week long experimental infection trial in rainbow trout with purified PRV-3 particles to assess the causal relationship between the virus and development of heart inflammation. The monitoring the PRV-3 load in heart and spleen by RT-qPCR shows a progressive increase of viral RNA to a peak, followed by clearance without a measurable change in haematocrit. The development of characteristic cardiac histopathological findings occurred in the late phase of the trial and was associated with increased expression of CD8+, indicating cytotoxic T cell proliferation. The findings indicate that, under these experimental conditions, PRV-3 infection in rainbow trout act similarly to PRV-1 infection in Atlantic salmon with regards to immunological responses and development of heart pathology, but not in the ability to establish a persistent infection.
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Affiliation(s)
- Niccoló Vendramin
- National Institute of Aquatic Resources, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Dhamotharan Kannimuthu
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | | | - Argelia Cuenca
- National Institute of Aquatic Resources, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Lena Hammerlund Teige
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Øystein Wessel
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Tine Moesgaard Iburg
- National Institute of Aquatic Resources, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Niels Jørgen Olesen
- National Institute of Aquatic Resources, Technical University of Denmark, Kongens Lyngby, Denmark
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29
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Wessel Ø, Krasnov A, Timmerhaus G, Rimstad E, Dahle MK. Antiviral Responses and Biological Concequences of Piscine orthoreovirus Infection in Salmonid Erythrocytes. Front Immunol 2019; 9:3182. [PMID: 30700987 PMCID: PMC6343427 DOI: 10.3389/fimmu.2018.03182] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 12/27/2018] [Indexed: 11/13/2022] Open
Abstract
Salmonid red blood cells are the main target cells for Piscine orthoreovirus (PRV). Three genotypes of PRV (PRV-1,2,3) infect Atlantic salmon (Salmo salar), Chinook salmon (Onchorhynchus tshawytscha), Coho salmon (Oncorhynchus kisutch), rainbow trout (Onchorhynchus mykiss) and brown trout (Salmo trutta), and can cause diseases like heart and skeletal muscle inflammation (HSMI), jaundice syndrome, erythrocyte inclusion body syndrome (EIBS) and proliferative darkening syndrome (PDS). Purified PRV administrated to fish has proven the causality for HSMI and EIBS. During the early peak phase of infection, salmonid erythrocytes are the main virus-replicating cells. In this initial phase, cytoplasmic inclusions called "virus factories" can be observed in the erythrocytes, and are the primary sites for the formation of new virus particles. The PRV-infected erythrocytes in Atlantic salmon mount a strong long-lasting innate antiviral response lasting for many weeks after the onset of infection. The antiviral response of Atlantic salmon erythrocytes involves upregulation of potential inhibitors of translation. In accordance with this, PRV-1 protein production in erythrocytes halts while virus RNA can persist for months. Furthermore, PRV infection in Coho salmon and rainbow trout are associated with anemia, and in Atlantic salmon lower hemoglobin levels are observed. Here we summarize and discuss the recently published findings on PRV infection, replication and effects on salmonid erythrocytes, and discuss how PRV can be a useful tool for the study of innate immune responses in erythrocytes, and help reveal novel immune functions of the red blood cells in fish.
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Affiliation(s)
- Øystein Wessel
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Aleksei Krasnov
- Division of Aquaculture, Norwegian Institute of Fisheries and Aquaculture (Nofima), Tromsø, Norway
| | - Gerrit Timmerhaus
- Division of Aquaculture, Norwegian Institute of Fisheries and Aquaculture (Nofima), Tromsø, Norway
| | - Espen Rimstad
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Maria K Dahle
- Department of Fish Health, Norwegian Veterinary Institute, Oslo, Norway.,The Norwegian College of Fishery Science, UiT The Arctic University of Norway, Tromsø, Norway
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30
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Røsaeg MV, Rimstad E, Guttvik A, Skjelstad B, Bendiksen EÅ, Garseth ÅH. Effect of pancreas disease caused by SAV 2 on protein and fat digestion in Atlantic salmon. J Fish Dis 2019; 42:97-108. [PMID: 30370677 DOI: 10.1111/jfd.12914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 09/17/2018] [Accepted: 09/18/2018] [Indexed: 05/13/2023]
Abstract
Salmonid alphavirus (SAV) causes pancreas disease (PD) in farmed Atlantic salmon (Salmo salar L.), and exocrine pancreas tissue is a primary target of the virus. Digestive enzymes secreted by the exocrine pancreas break down macromolecules in feed into smaller molecules that can be absorbed. The effect of SAV infection on digestion has been poorly studied. In this study, longitudinal observations of PD outbreaks caused by SAV subtype 2 (SAV2) in Atlantic salmon at two commercial sea sites were performed. The development of PD was assessed by measurement of SAV2 RNA load and evaluation of histopathological lesions typical of PD. Reduced digestion of both protein and fat co-varied with the severity of PD lesions and viral load. Also, the study found that during a PD outbreak, the pen population comprise several subpopulations, with different likelihoods of being sampled. The body length of sampled fish deviated from the expected increase or steady state over time, and the infection status in sampled fish deviated from the expected course of infection in the population. Both conditions indicate that disease status of the individual fish influenced the likelihood of being sampled, which may cause sampling bias in population studies.
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Affiliation(s)
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
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31
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Adamek M, Hellmann J, Flamm A, Teitge F, Vendramin N, Fey D, Riße K, Blakey F, Rimstad E, Steinhagen D. Detection of piscine orthoreoviruses (PRV-1 and PRV-3) in Atlantic salmon and rainbow trout farmed in Germany. Transbound Emerg Dis 2018; 66:14-21. [PMID: 30230250 DOI: 10.1111/tbed.13018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 08/06/2018] [Accepted: 09/06/2018] [Indexed: 01/10/2023]
Abstract
Piscine orthoreoviruses (PRVs) are emerging pathogens causing circulatory disorders in salmonids. PRV-1 is the etiological cause of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar), characterized by epicarditis, inflammation and necrosis of the myocardium, myositis and necrosis of red skeletal muscle. In 2017, two German breeding farms for Atlantic salmon and rainbow trout (Oncorhynchus mykiss) experienced disease outbreaks with mortalities of 10% and 20% respectively. The main clinical signs were exhaustion and lethargic behaviour. During examinations, PRV-1 in salmon and PRV-3 in trout were detected for the first time in Germany. Further analyses also indicated the presence of Aeromonas salmonicida in internal tissues of both species. While PRV-1 could be putatively linked with the disease in Atlantic salmon, most of the rainbow trout suffered from an infection with A. salmonicida and not with PRV-3. Interestingly, the sequence analysis suggests that the German PRV-3 isolate is more similar to a Chilean PRV-3 isolate from Coho salmon (Oncorhynchus kisutch) than to PRV-3 from rainbow trout from Norway. This indicates a wide geographic distribution of this virus or dispersal by global trade. These findings indicate that infections with PRVs should be considered when investigating disease outbreaks in salmonids.
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Affiliation(s)
- Mikolaj Adamek
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine, Hannover, Germany
| | - John Hellmann
- Department Fisheries Ecology, North Rhine Westphalian State Agency for Nature, Environment and Consumer Protection, Albaum, Germany
| | - Agnes Flamm
- Hesse State Laboratory, Control of Fish Diseases, Giessen, Germany
| | - Felix Teitge
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine, Hannover, Germany
| | - Niccolò Vendramin
- Fish Diseases, Division for Diagnostics & Scientific Advice, National Veterinary Institute, Technical University of Denmark, Lyngby, Denmark
| | - Daniel Fey
- Department Fisheries Ecology, North Rhine Westphalian State Agency for Nature, Environment and Consumer Protection, Albaum, Germany
| | - Karin Riße
- Hesse State Laboratory, Control of Fish Diseases, Giessen, Germany
| | - Franziska Blakey
- Hesse State Laboratory, Control of Fish Diseases, Giessen, Germany
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Dieter Steinhagen
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine, Hannover, Germany
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32
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Haatveit HM, Hodneland K, Braaen S, Hansen EF, Nyman IB, Dahle MK, Frost P, Rimstad E. DNA vaccine expressing the non-structural proteins of Piscine orthoreovirus delay the kinetics of PRV infection and induces moderate protection against heart -and skeletal muscle inflammation in Atlantic salmon (Salmo salar). Vaccine 2018; 36:7599-7608. [PMID: 30392768 DOI: 10.1016/j.vaccine.2018.10.094] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 10/23/2018] [Accepted: 10/30/2018] [Indexed: 01/08/2023]
Abstract
Piscine orthoreovirus (PRV) causes heart- and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar). Erythrocytes are the main target cells for PRV. HSMI causes significant economic losses to the salmon aquaculture industry, and there is currently no vaccine available. PRV replicates and assembles within cytoplasmic structures called viral factories, mainly organized by the non-structural viral protein µNS. In two experimental vaccination trials in Atlantic salmon, using DNA vaccines expressing different combinations of PRV proteins, we found that expression of the non-structural proteins µNS combined with the cell attachment protein σ1 was associated with an increasing trend in lymphocyte marker gene expression in spleen, and induced moderate protective effect against HSMI.
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Affiliation(s)
- Hanne M Haatveit
- Department of Food Safety and Infectious Biology, Norwegian University of Life Sciences, 0454 Oslo, Norway
| | | | - Stine Braaen
- Department of Food Safety and Infectious Biology, Norwegian University of Life Sciences, 0454 Oslo, Norway
| | - Elisabeth F Hansen
- Department of Food Safety and Infectious Biology, Norwegian University of Life Sciences, 0454 Oslo, Norway
| | - Ingvild B Nyman
- Department of Food Safety and Infectious Biology, Norwegian University of Life Sciences, 0454 Oslo, Norway
| | | | | | - Espen Rimstad
- Department of Food Safety and Infectious Biology, Norwegian University of Life Sciences, 0454 Oslo, Norway.
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33
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Wessel Ø, Haugland Ø, Rode M, Fredriksen BN, Dahle MK, Rimstad E. Inactivated Piscine orthoreovirus vaccine protects against heart and skeletal muscle inflammation in Atlantic salmon. J Fish Dis 2018; 41:1411-1419. [PMID: 29926926 DOI: 10.1111/jfd.12835] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 05/18/2023]
Abstract
Heart- and skeletal muscle inflammation (HSMI) caused by infection with Piscine orthoreovirus (PRV) is one of the most common viral diseases in farmed Atlantic salmon (Salmo salar) in Norway, and disease outbreaks have been reported in most countries with large-scale Atlantic salmon aquaculture. Currently there is no vaccine available for protection against HSMI, partly due to the lack of a cell line for efficient virus propagation. Erythrocytes are the primary target cells for PRV in vivo and a potential source for isolation of PRV particles. In this study, PRV was purified from infected erythrocytes, inactivated and used in a vaccination trial against HSMI. A single immunization with adjuvanted, inactivated PRV induced protection against HSMI in Atlantic salmon infected by virus injection 6 weeks later, while a moderate protection was obtained in fish infected through natural transmission, i.e. cohabitation. The PRV vaccine significantly reduced PRV loads and histopathological lesions typical for HSMI compared to the unvaccinated control group. This is the first demonstration of protective vaccination against PRV, and promising for future control of HSMI in Atlantic salmon aquaculture.
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Affiliation(s)
- Øystein Wessel
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | | | | | | | - Maria K Dahle
- Department of Fish Health, Norwegian Veterinary Institute, Oslo, Norway
| | - Espen Rimstad
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
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34
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Vendramin N, Alencar ALF, Iburg TM, Dahle MK, Wessel Ø, Olsen AB, Rimstad E, Olesen NJ. Piscine orthoreovirus infection in Atlantic salmon (Salmo salar) protects against subsequent challenge with infectious hematopoietic necrosis virus (IHNV). Vet Res 2018. [PMID: 29534748 PMCID: PMC5850924 DOI: 10.1186/s13567-018-0524-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Infectious hematopoietic necrosis virus (IHNV) is endemic in farmed rainbow trout in continental Europe and in various salmonid fish species at the Pacific coast of North America. IHN has never occurred in European Atlantic salmon (Salmo salar) farms, but is considered as a major threat for the European salmon industry. Another virus, Piscine orthoreovirus (PRV), is widespread in the sea phase of Atlantic salmon, and is identified as the causative agent of heart and skeletal muscle inflammation. The aim of this study was to investigate the interactions between a primary PRV infection and a secondary IHNV infection under experimental conditions. A PRV cohabitation challenge was performed with Atlantic salmon. At peak of PRV viremia the fish were challenged by immersion with an IHNV genogroup E isolate. Clinical signs and morbidity were monitored. Target organs were sampled at selected time points to assess viral loads of both pathogens. Antiviral immune response and presence of histopathological findings were also investigated. Whereas the PRV-negative/IHNV positive group suffered significant decrease in survival caused by IHNV, the PRV infected groups did not suffer any morbidity and showed negligible levels of IHNV infection. Antiviral response genes were induced, as measured in spleen samples, from PRV infected fish prior to IHNV challenge. In conclusion, PRV-infection protects Atlantic salmon against IHNV infection and morbidity, most likely by inducing a protective innate antiviral response.
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Affiliation(s)
- Niccoló Vendramin
- National Veterinary Institute, Technical University of Denmark, Copenhagen, Denmark.
| | | | - Tine Moesgaard Iburg
- National Veterinary Institute, Technical University of Denmark, Copenhagen, Denmark
| | | | - Øystein Wessel
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | | | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Niels Jørgen Olesen
- National Veterinary Institute, Technical University of Denmark, Copenhagen, Denmark
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35
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Büyükekiz AG, Altun S, Hansen EF, Satıcıoğlu IB, Duman M, Markussen T, Rimstad E. Infectious pancreatic necrosis virus (IPNV) serotype Sp is prevalent in Turkish rainbow trout farms. J Fish Dis 2018; 41:95-104. [PMID: 28745835 DOI: 10.1111/jfd.12675] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 05/29/2017] [Accepted: 05/30/2017] [Indexed: 06/07/2023]
Abstract
Infectious pancreatic necrosis virus (IPNV) is a common pathogen of rainbow trout (Oncorhynchus mykiss) in Turkey. We found that 455 of 1,676 sample pools tested were IPNV positive. Positive samples were found in all geographical regions where sampling was conducted. Sequence and phylogenetic analyses of VP2 from 30 isolates representing all regions showed that the viruses were highly similar in sequence and grouped within Genogroup 5 (serotype Sp-A2). No correlations between sequences, sampling sites or geographical origins were identified. Although clinical disease was evident in several farms, analyses of the amino acid sequence of VP2 showed that all virus strains harboured the P217 T221 motif, assumed to be associated with low virulence. We conclude that IPNV is prevalent in Turkish rainbow trout farms and that the viruses are very homogenous and likely to be of European origin. Frequent exchange of eggs and live fish within the farming industry may explain the homogeneity of the IPNV.
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Affiliation(s)
- A G Büyükekiz
- Department of Aquatic Animal Diseases, Faculty of Veterinary Medicine, Uludag University, Bursa, Turkey
| | - S Altun
- Department of Aquatic Animal Diseases, Faculty of Veterinary Medicine, Uludag University, Bursa, Turkey
| | - E F Hansen
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - I B Satıcıoğlu
- Department of Aquatic Animal Diseases, Faculty of Veterinary Medicine, Uludag University, Bursa, Turkey
| | - M Duman
- Department of Aquatic Animal Diseases, Faculty of Veterinary Medicine, Uludag University, Bursa, Turkey
| | - T Markussen
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - E Rimstad
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
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36
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Thukral V, Varshney B, Ramly RB, Ponia SS, Mishra SK, Olsen CM, Banerjea AC, Mukherjee SK, Zaidi R, Rimstad E, Lal SK. s8ORF2 protein of infectious salmon anaemia virus is a RNA-silencing suppressor and interacts with Salmon salar Mov10 (SsMov10) of the host RNAi machinery. Virus Genes 2017; 54:199-214. [PMID: 29218433 PMCID: PMC7089075 DOI: 10.1007/s11262-017-1526-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 11/22/2017] [Indexed: 12/24/2022]
Abstract
The infectious salmon anaemia virus (ISAV) is a piscine virus, a member of Orthomyxoviridae family. It encodes at least 10 proteins from eight negative-strand RNA segments. Since ISAV belongs to the same virus family as Influenza A virus, with similarities in protein functions, they may hence be characterised by analogy. Like NS1 protein of Influenza A virus, s8ORF2 of ISAV is implicated in interferon antagonism and RNA-binding functions. In this study, we investigated the role of s8ORF2 in RNAi suppression in a well-established Agrobacterium transient suppression assay in stably silenced transgenic Nicotiana xanthi. In addition, s8ORF2 was identified as a novel interactor with SsMov10, a key molecule responsible for RISC assembly and maturation in the RNAi pathway. This study thus sheds light on a novel route undertaken by viral proteins in promoting viral growth, using the host RNAi machinery.
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Affiliation(s)
- Vandana Thukral
- Virology & Plant Molecular Biology Groups, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi, 110067, India
| | - Bhavna Varshney
- Virology & Plant Molecular Biology Groups, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi, 110067, India
| | - Rimatulhana B Ramly
- Norwegian University of Life Science, P.O. Box 8146 Dep., 0033, Oslo, Norway
| | - Sanket S Ponia
- Department of Virology, National Institute of Immunology, New Delhi, 110067, India
| | - Sumona Karjee Mishra
- Virology & Plant Molecular Biology Groups, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi, 110067, India.,Prantae Solutions Pvt. Ltd., KIIT-Campus 11, Bhubaneswar, Odisha, India
| | - Christel M Olsen
- Norwegian University of Life Science, P.O. Box 8146 Dep., 0033, Oslo, Norway
| | - Akhil C Banerjea
- Department of Virology, National Institute of Immunology, New Delhi, 110067, India
| | - Sunil K Mukherjee
- Virology & Plant Molecular Biology Groups, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi, 110067, India
| | - Rana Zaidi
- Department of Biochemistry, Faculty of Science, Jamia Hamdard, New Delhi, 110062, India
| | - Espen Rimstad
- Norwegian University of Life Science, P.O. Box 8146 Dep., 0033, Oslo, Norway
| | - Sunil K Lal
- Virology & Plant Molecular Biology Groups, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi, 110067, India. .,School of Science, Monash University, Sunway Campus, Selangor, 47500, Malaysia.
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37
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Tengs T, Rimstad E. Emerging pathogens in the fish farming industry and sequencing-based pathogen discovery. Dev Comp Immunol 2017; 75:109-119. [PMID: 28167074 DOI: 10.1016/j.dci.2017.01.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 01/27/2017] [Accepted: 01/31/2017] [Indexed: 06/06/2023]
Abstract
The use of large scale DNA/RNA sequencing has become an integral part of biomedical research. Reduced sequencing costs and the availability of efficient computational resources has led to a revolution in how problems concerning genomics and transcriptomics are addressed. Sequencing-based pathogen discovery represents one example of how genetic data can now be used in ways that were previously considered infeasible. Emerging pathogens affect both human and animal health due to a multitude of factors, including globalization, a shifting environment and an increasing human population. Fish farming represents a relevant, interesting and challenging system to study emerging pathogens. This review summarizes recent progress in pathogen discovery using sequence data, with particular emphasis on viruses in Atlantic salmon (Salmo salar).
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Affiliation(s)
- Torstein Tengs
- Department of Chemistry, Biotechnology and Food Sciences, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, 1430 Aas, Norway.
| | - Espen Rimstad
- Department of Food Safety and Infectious Biology, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, 0033 Oslo, Norway
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38
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Wessel Ø, Braaen S, Alarcon M, Haatveit H, Roos N, Markussen T, Tengs T, Dahle MK, Rimstad E. Infection with purified Piscine orthoreovirus demonstrates a causal relationship with heart and skeletal muscle inflammation in Atlantic salmon. PLoS One 2017; 12:e0183781. [PMID: 28841684 PMCID: PMC5571969 DOI: 10.1371/journal.pone.0183781] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 08/10/2017] [Indexed: 01/07/2023] Open
Abstract
Viral diseases pose a significant threat to the productivity in aquaculture. Heart- and skeletal muscle inflammation (HSMI) is an emerging disease in Atlantic salmon (Salmo salar) farming. HSMI is associated with Piscine orthoreovirus (PRV) infection, but PRV is ubiquitous in farmed Atlantic salmon and thus present also in apparently healthy individuals. This has brought speculations if additional etiological factors are required, and experiments focusing on the causal relationship between PRV and HSMI are highly warranted. A major bottleneck in PRV research has been the lack of cell lines that allow propagation of the virus. To bypass this, we propagated PRV in salmon, bled the fish at the peak of the infection, and purified virus particles from blood cells. Electron microscopy, western blot and high-throughput sequencing all verified the purity of the viral particles. Purified PRV particles were inoculated into naïve Atlantic salmon. The purified virus replicated in inoculated fish, spread to naïve cohabitants, and induced histopathological changes consistent with HSMI. PRV specific staining was demonstrated in the pathological lesions. A dose-dependent response was observed; a high dose of virus gave earlier peak of the viral load and development of histopathological changes compared to a lower dose, but no difference in the severity of the disease. The experiment demonstrated that PRV can be purified from blood cells, and that PRV is the etiological agent of HSMI in Atlantic salmon.
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Affiliation(s)
- Øystein Wessel
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
- * E-mail:
| | - Stine Braaen
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | | | - Hanne Haatveit
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Norbert Roos
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Turhan Markussen
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Torstein Tengs
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | | | - Espen Rimstad
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
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39
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Lund M, Krudtaa Dahle M, Timmerhaus G, Alarcon M, Powell M, Aspehaug V, Rimstad E, Jørgensen SM. Hypoxia tolerance and responses to hypoxic stress during heart and skeletal muscle inflammation in Atlantic salmon (Salmo salar). PLoS One 2017; 12:e0181109. [PMID: 28700748 PMCID: PMC5507449 DOI: 10.1371/journal.pone.0181109] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 06/25/2017] [Indexed: 12/17/2022] Open
Abstract
Heart and skeletal muscle inflammation (HSMI) is associated with Piscine orthoreovirus (PRV) infection and is an important disease in Atlantic salmon (Salmo salar) aquaculture. Since PRV infects erythrocytes and farmed salmon frequently experience environmental hypoxia, the current study examined mutual effects of PRV infection and hypoxia on pathogenesis and fish performance. Furthermore, effects of HSMI on hypoxia tolerance, cardiorespiratory performance and blood oxygen transport were studied. A cohabitation trial including PRV-infected post-smolts exposed to periodic hypoxic stress (4 h of 40% O2; PRV-H) at 4, 7 and 10 weeks post-infection (WPI) and infected fish reared under normoxic conditions (PRV) was conducted. Periodic hypoxic stress did not influence infection levels or histopathological changes in the heart. Individual incipient lethal oxygen saturation (ILOS) was examined using a standardized hypoxia challenge test (HCT). At 7 WPI, i.e. peak level of infection, both PRV and PRV-H groups exhibited reduced hypoxia tolerance compared to non-infected fish. Three weeks later (10 WPI), during peak levels of pathological changes, reduced hypoxia tolerance was still observed for the PRV group while PRV-H performed equal to non-infected fish, implying a positive effect of the repeated exposure to hypoxic stress. This was in line with maximum heart rate (fHmax) measurements, showing equal performance of PRV-H and non-infected groups, but lower fHmax above 19°C as well as lower temperature optimum (Topt) for aerobic scope for PRV, suggesting reduced cardiac performance and thermal tolerance. In contrast, the PRV-H group had reduced hemoglobin-oxygen affinity compared to non-infected fish. In conclusion, Atlantic salmon suffering from HSMI have reduced hypoxia tolerance and cardiac performance, which can be improved by preconditioning fish to transient hypoxic stress episodes.
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Affiliation(s)
- Morten Lund
- Section of Immunology, Norwegian Veterinary Institute, Oslo and Harstad, Norway
- * E-mail:
| | - Maria Krudtaa Dahle
- Section of Immunology, Norwegian Veterinary Institute, Oslo and Harstad, Norway
| | - Gerrit Timmerhaus
- Nofima AS, Norwegian Institute of Food, Fisheries & Aquaculture Research, Ås, Norway
| | - Marta Alarcon
- Section of Immunology, Norwegian Veterinary Institute, Oslo and Harstad, Norway
| | - Mark Powell
- University of Bergen, Bergen, Norway
- Norwegian Institute for Water Research, Bergen, Norway
| | | | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Sven Martin Jørgensen
- Nofima AS, Norwegian Institute of Food, Fisheries & Aquaculture Research, Ås, Norway
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40
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Røsæg MV, Lund M, Nyman IB, Markussen T, Aspehaug V, Sindre H, Dahle MK, Rimstad E. Immunological interactions between Piscine orthoreovirus and Salmonid alphavirus infections in Atlantic salmon. Fish Shellfish Immunol 2017; 64:308-319. [PMID: 28323214 DOI: 10.1016/j.fsi.2017.03.036] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 03/14/2017] [Accepted: 03/17/2017] [Indexed: 06/06/2023]
Abstract
Heart and skeletal muscle inflammation (HSMI) and pancreas disease (PD) cause substantial losses in Atlantic salmon (Salmo salar) aquaculture. The respective causative agents, Piscine orthoreovirus (PRV) and Salmonid alphavirus (SAV), are widespread and often concurrently present in farmed salmon. An experimental infection in Atlantic salmon was conducted to study the interaction between the two viruses, including the immunological mechanisms involved. The co-infected fish were infected with PRV four or ten weeks before they were infected with SAV. The SAV RNA level and the PD specific lesions were significantly lower in co-infected groups compared to the group infected by only SAV. The expression profiles of a panel of innate antiviral response genes and the plasma SAV neutralization titers were examined. The innate antiviral response genes were in general upregulated for at least ten weeks after the primary PRV infection. Plasma from co-infected fish had lower SAV neutralizing titers compared to the controls infected with only SAV. Plasma from some individuals infected with only PRV neutralized SAV, but heat treatment removed this effect. Field studies of co-infected fish populations indicated a negative correlation between the two viruses in randomly sampled apparently healthy fish, in line with the experimental findings, but a positive correlation in moribund or dead fish. The results indicate that the innate antiviral response induced by PRV may temporary protect against a secondary SAV infection.
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Affiliation(s)
- Magnus Vikan Røsæg
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway; SalMar ASA, Kverva, Norway
| | - Morten Lund
- Sections of Immunology and Virology, Norwegian Veterinary Institute, Oslo, Norway
| | - Ingvild Berg Nyman
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Turhan Markussen
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | | | - Hilde Sindre
- Sections of Immunology and Virology, Norwegian Veterinary Institute, Oslo, Norway
| | - Maria Krudtaa Dahle
- Sections of Immunology and Virology, Norwegian Veterinary Institute, Oslo, Norway
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway.
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41
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Haatveit HM, Wessel Ø, Markussen T, Lund M, Thiede B, Nyman IB, Braaen S, Dahle MK, Rimstad E. Viral Protein Kinetics of Piscine Orthoreovirus Infection in Atlantic Salmon Blood Cells. Viruses 2017; 9:v9030049. [PMID: 28335455 PMCID: PMC5371804 DOI: 10.3390/v9030049] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 03/07/2017] [Accepted: 03/10/2017] [Indexed: 01/12/2023] Open
Abstract
Piscine orthoreovirus (PRV) is ubiquitous in farmed Atlantic salmon (Salmo salar) and the cause of heart and skeletal muscle inflammation. Erythrocytes are important target cells for PRV. We have investigated the kinetics of PRV infection in salmon blood cells. The findings indicate that PRV causes an acute infection of blood cells lasting 1–2 weeks, before it subsides into persistence. A high production of viral proteins occurred initially in the acute phase which significantly correlated with antiviral gene transcription. Globular viral factories organized by the non-structural protein µNS were also observed initially, but were not evident at later stages. Interactions between µNS and the PRV structural proteins λ1, µ1, σ1 and σ3 were demonstrated. Different size variants of µNS and the outer capsid protein µ1 appeared at specific time points during infection. Maximal viral protein load was observed five weeks post cohabitant challenge and was undetectable from seven weeks post challenge. In contrast, viral RNA at a high level could be detected throughout the eight-week trial. A proteolytic cleavage fragment of the µ1 protein was the only viral protein detectable after seven weeks post challenge, indicating that this µ1 fragment may be involved in the mechanisms of persistent infection.
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Affiliation(s)
- Hanne Merethe Haatveit
- Department of Food Safety and Infectious Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
| | - Øystein Wessel
- Department of Food Safety and Infectious Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
| | - Turhan Markussen
- Department of Food Safety and Infectious Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
| | - Morten Lund
- Department of Immunology, Norwegian Veterinary Institute, 0454 Oslo, Norway.
| | - Bernd Thiede
- Department of Biosciences, University of Oslo, 0316 Oslo, Norway.
| | - Ingvild Berg Nyman
- Department of Food Safety and Infectious Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
| | - Stine Braaen
- Department of Food Safety and Infectious Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
| | - Maria Krudtaa Dahle
- Department of Immunology, Norwegian Veterinary Institute, 0454 Oslo, Norway.
| | - Espen Rimstad
- Department of Food Safety and Infectious Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
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42
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Di Cicco E, Ferguson HW, Schulze AD, Kaukinen KH, Li S, Vanderstichel R, Wessel Ø, Rimstad E, Gardner IA, Hammell KL, Miller KM. Heart and skeletal muscle inflammation (HSMI) disease diagnosed on a British Columbia salmon farm through a longitudinal farm study. PLoS One 2017; 12:e0171471. [PMID: 28225783 PMCID: PMC5321275 DOI: 10.1371/journal.pone.0171471] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 01/20/2017] [Indexed: 01/24/2023] Open
Abstract
Heart and skeletal muscle inflammation (HSMI) is an emerging disease of marine-farmed Atlantic Salmon (Salmo salar), first recognized in 1999 in Norway, and later also reported in Scotland and Chile. We undertook a longitudinal study involving health evaluation over an entire marine production cycle on one salmon farm in British Columbia (Canada). In previous production cycles at this farm site and others in the vicinity, cardiac lesions not linked to a specific infectious agent or disease were identified. Histologic assessments of both live and moribund fish samples collected at the farm during the longitudinal study documented at the population level the development, peak, and recovery phases of HSMI. The fish underwent histopathological evaluation of all tissues, Twort’s Gram staining, immunohistochemistry, and molecular quantification in heart tissue of 44 agents known or suspected to cause disease in salmon. Our analysis showed evidence of HSMI histopathological lesions over an 11-month timespan, with the prevalence of lesions peaking at 80–100% in sampled fish, despite mild clinical signs with no associated elevation in mortalities reported at the farm level. Diffuse mononuclear inflammation and myodegeneration, consistent with HSMI, was the predominant histologic observation in affected heart and skeletal muscle. Infective agent monitoring identified three agents at high prevalence in salmon heart tissue, including Piscine orthoreovirus (PRV), and parasites Paranucleospora theridion and Kudoa thyrsites. However, PRV alone was statistically correlated with the occurrence and severity of histopathological lesions in the heart. Immunohistochemical staining further localized PRV throughout HSMI development, with the virus found mainly within red blood cells in early cases, moving into the cardiomyocytes within or, more often, on the periphery of the inflammatory reaction during the peak disease, and reducing to low or undetectable levels later in the production cycle. This study represents the first longitudinal assessment of HSMI in a salmon farm in British Columbia, providing new insights on the pathogenesis of the disease.
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Affiliation(s)
- Emiliano Di Cicco
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
- Pacific Salmon Foundation, Vancouver, British Columbia, Canada
- * E-mail: (ED); (KMM)
| | - Hugh W. Ferguson
- School of Veterinary Medicine, St. George's University, Grenada, W. Indies
| | - Angela D. Schulze
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | - Karia H. Kaukinen
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | - Shaorong Li
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | - Raphaël Vanderstichel
- Centre for Veterinary Epidemiological Research, Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Øystein Wessel
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Ian A. Gardner
- Centre for Veterinary Epidemiological Research, Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - K. Larry Hammell
- Centre for Veterinary Epidemiological Research, Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Kristina M. Miller
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
- * E-mail: (ED); (KMM)
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43
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Lund M, Røsæg MV, Krasnov A, Timmerhaus G, Nyman IB, Aspehaug V, Rimstad E, Dahle MK. Experimental Piscine orthoreovirus infection mediates protection against pancreas disease in Atlantic salmon (Salmo salar). Vet Res 2016; 47:107. [PMID: 27769313 PMCID: PMC5075195 DOI: 10.1186/s13567-016-0389-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/04/2016] [Indexed: 11/10/2022] Open
Abstract
Viral diseases are among the main challenges in farming of Atlantic salmon (Salmo salar). The most prevalent viral diseases in Norwegian salmon aquaculture are heart and skeletal muscle inflammation (HSMI) caused by Piscine orthoreovirus (PRV), and pancreas disease (PD) caused by Salmonid alphavirus (SAV). Both PRV and SAV target heart and skeletal muscles, but SAV additionally targets exocrine pancreas. PRV and SAV are often present in the same locations and co-infections occur, but the effect of this crosstalk on disease development has not been investigated. In the present experiment, the effect of a primary PRV infection on subsequent SAV infection was studied. Atlantic salmon were infected with PRV by cohabitation, followed by addition of SAV shedder fish 4 or 10 weeks after the initial PRV infection. Histopathological evaluation, monitoring of viral RNA levels and host gene expression analysis were used to assess disease development. Significant reduction of SAV RNA levels and of PD specific histopathological changes were observed in the co-infected groups compared to fish infected by SAV only. A strong correlation was found between histopathological development and expression of disease related genes in heart. In conclusion, experimentally PRV infected salmon are less susceptible to secondary SAV infection and development of PD.
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Affiliation(s)
- Morten Lund
- Section of Immunology, Norwegian Veterinary Institute, Oslo, Norway
| | - Magnus Vikan Røsæg
- SalMar ASA, Kverva, Norway.,Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Aleksei Krasnov
- Nofima AS, Norwegian Institute of Food, Fisheries and Aquaculture Research, Ås, Norway
| | - Gerrit Timmerhaus
- Nofima AS, Norwegian Institute of Food, Fisheries and Aquaculture Research, Ås, Norway
| | - Ingvild Berg Nyman
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | | | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
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44
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Reperant LA, Brown IH, Haenen OL, de Jong MD, Osterhaus ADME, Papa A, Rimstad E, Valarcher JF, Kuiken T. Companion Animals as a Source of Viruses for Human Beings and Food Production Animals. J Comp Pathol 2016; 155:S41-53. [PMID: 27522300 DOI: 10.1016/j.jcpa.2016.07.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 07/04/2016] [Accepted: 07/07/2016] [Indexed: 01/12/2023]
Abstract
Companion animals comprise a wide variety of species, including dogs, cats, horses, ferrets, guinea pigs, reptiles, birds and ornamental fish, as well as food production animal species, such as domestic pigs, kept as companion animals. Despite their prominent place in human society, little is known about the role of companion animals as sources of viruses for people and food production animals. Therefore, we reviewed the literature for accounts of infections of companion animals by zoonotic viruses and viruses of food production animals, and prioritized these viruses in terms of human health and economic importance. In total, 138 virus species reportedly capable of infecting companion animals were of concern for human and food production animal health: 59 of these viruses were infectious for human beings, 135 were infectious for food production mammals and birds, and 22 were infectious for food production fishes. Viruses of highest concern for human health included hantaviruses, Tahyna virus, rabies virus, West Nile virus, tick-borne encephalitis virus, Crimean-Congo haemorrhagic fever virus, Aichi virus, European bat lyssavirus, hepatitis E virus, cowpox virus, G5 rotavirus, influenza A virus and lymphocytic choriomeningitis virus. Viruses of highest concern for food production mammals and birds included bluetongue virus, African swine fever virus, foot-and-mouth disease virus, lumpy skin disease virus, Rift Valley fever virus, porcine circovirus, classical swine fever virus, equine herpesvirus 9, peste des petits ruminants virus and equine infectious anaemia virus. Viruses of highest concern for food production fishes included cyprinid herpesvirus 3 (koi herpesvirus), viral haemorrhagic septicaemia virus and infectious pancreatic necrosis virus. Of particular concern as sources of zoonotic or food production animal viruses were domestic carnivores, rodents and food production animals kept as companion animals. The current list of viruses provides an objective basis for more in-depth analysis of the risk of companion animals as sources of viruses for human and food production animal health.
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Affiliation(s)
- L A Reperant
- Department of Viroscience, Erasmus Medical Centre, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - I H Brown
- Animal and Plant Health Agency Weybridge, New Haw, Addlestone, Surrey, UK
| | - O L Haenen
- National Reference Laboratory for Fish, Shellfish and Crustacean Diseases, Central Veterinary Institute of Wageningen UR, PO Box 65, 8200 AB Lelystad, The Netherlands
| | - M D de Jong
- Department of Medical Microbiology, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - A D M E Osterhaus
- Department of Viroscience, Erasmus Medical Centre, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - A Papa
- Department of Microbiology, Medical School Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - E Rimstad
- Department of Food Safety and Infection Biology, University of Life Sciences, Oslo, Norway
| | - J-F Valarcher
- Department of Virology, Immunology, and Parasitology, National Veterinary Institute, Uppsala, Sweden
| | - T Kuiken
- Department of Viroscience, Erasmus Medical Centre, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
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Johansen LH, Dahle MK, Wessel Ø, Timmerhaus G, Løvoll M, Røsæg M, Jørgensen SM, Rimstad E, Krasnov A. Differences in gene expression in Atlantic salmon parr and smolt after challenge with Piscine orthoreovirus (PRV). Mol Immunol 2016; 73:138-50. [DOI: 10.1016/j.molimm.2016.04.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/11/2016] [Accepted: 04/12/2016] [Indexed: 12/25/2022]
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46
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Bjørgen H, Wessel Ø, Fjelldal PG, Hansen T, Sveier H, Sæbø HR, Enger KB, Monsen E, Kvellestad A, Rimstad E, Koppang EO. Piscine orthoreovirus (PRV) in red and melanised foci in white muscle of Atlantic salmon (Salmo salar). Vet Res 2015; 46:89. [PMID: 26346256 PMCID: PMC4562189 DOI: 10.1186/s13567-015-0244-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 08/17/2015] [Indexed: 11/10/2022] Open
Abstract
Melanised focal changes (black spots) are common findings in the white skeletal muscle of seawater-farmed Atlantic salmon (Salmo salar). Fillets with melanised focal changes are considered as lower quality and cause large economic losses. It has been suggested that red focal changes (red spots) precede the melanised focal changes. In the present work, we examined different populations of captive and wild salmon for the occurrence of both types of changes, which were investigated for the presence of different viruses by immunohistochemistry and RT-qPCR. The occurrence of red or melanised foci varied significantly between the populations, from none in wild fish control group, low prevalence of small foci in fish kept in in-house tanks, to high prevalence of large foci in farm-raised salmon. Large amounts of Piscine orthoreovirus (PRV) antigen were detected in all foci. No other viruses were detected. Red focal changes contained significantly higher levels of PRV RNA than apparently non-affected areas in white muscle of the same individuals. Some changes displayed a transient form between a red and melanised pathotype, indicating a progression from an acute to a chronic manifestation. We conclude that PRV is associated with the focal pathological changes in the white muscle of farmed Atlantic salmon and is a premise for the development of focal melanised changes.
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Affiliation(s)
- Håvard Bjørgen
- Institute of Basic Science and Aquatic Medicine, School of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway.
| | - Øystein Wessel
- Institute of Food Safety and Infection Biology, School of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway.
| | | | - Tom Hansen
- Matre Research Station, Institute of Marine Research, Matre, Norway.
| | | | - Håkon Rydland Sæbø
- Department Brandasund and Rex Star, Lerøy Sjøtroll AS, Skjervøy, Norway.
| | | | | | - Agnar Kvellestad
- Institute of Basic Science and Aquatic Medicine, School of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway.
| | - Espen Rimstad
- Institute of Food Safety and Infection Biology, School of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway.
| | - Erling Olaf Koppang
- Institute of Basic Science and Aquatic Medicine, School of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway.
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47
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Myrmel M, Lange H, Rimstad E. A 1-Year Quantitative Survey of Noro-, Adeno-, Human Boca-, and Hepatitis E Viruses in Raw and Secondarily Treated Sewage from Two Plants in Norway. Food Environ Virol 2015; 7:213-23. [PMID: 26003323 DOI: 10.1007/s12560-015-9200-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 05/16/2015] [Indexed: 05/27/2023]
Abstract
A study of enteric viruses in raw and treated sewage from two secondary treatment plants, which received sewage from Oslo city (plant A) and small municipalities in Hedmark county in Norway (plant B), showed high levels of noro-, adeno-, and bocavirus throughout the year. A seasonal variation was observed for adeno- and GII norovirus with higher levels during winter and bocavirus that had more positive samples during winter. The virus concentrations in raw sewage were comparable in the two plants, with medians (log10 genome copies per liter) of 6.1, 6.3, 6.0, and 4.5 for noro GI, noro GII, adeno-, and bocavirus, respectively. The level of hepatitis E virus was not determined as it was below the limit of quantification. The mean log10 virus reduction was 0.55 (plant A) and 1.44 (plant B) with the highest reduction found in the plant with longer hydraulic retention time. The adenoviruses were dominantly serotype 41, while serotype 12 appeared sporadically. Of the 102 raw and treated sewage samples that were tested, eight were positive for hepatitis E virus of which four were from treated sewage. Two of the four obtained gene sequences from hepatitis E virus originated from the rural sewage samples and showed high similarity with a genotype 3 strain of hepatitis E virus detected in local piglets. Two other hepatitis E virus sequences obtained from urban sewage samples showed high similarities with genotype 3 strains isolated from urban sewage in Spain and a human genotype 1 isolate from India. The study gives information on the levels of noroviruses in raw and treated sewage, which is valuable to risk assessment, information indicating that some infections with hepatitis E viruses in Norway have a regional origin and that human bocavirus 2 and 3 are prevalent in the Norwegian population.
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Affiliation(s)
- M Myrmel
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, Oslo, Norway,
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48
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Dahle MK, Wessel Ø, Timmerhaus G, Nyman IB, Jørgensen SM, Rimstad E, Krasnov A. Transcriptome analyses of Atlantic salmon (Salmo salar L.) erythrocytes infected with piscine orthoreovirus (PRV). Fish Shellfish Immunol 2015; 45:780-790. [PMID: 26057463 DOI: 10.1016/j.fsi.2015.05.049] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 05/24/2015] [Accepted: 05/29/2015] [Indexed: 06/04/2023]
Abstract
Heart and skeletal muscle inflammation (HSMI) is a widespread disease of farmed Atlantic salmon (Salmo salar L.) and is associated with piscine orthoreovirus (PRV) infection. PRV is detectable in blood long before development of pathology in cardiac- and skeletal muscle appear, and erythrocytes have been identified as important target cells for the virus. The effects of PRV infection on cellular processes of erythrocytes are not known, but haemolytic anemia or systemic lysis of erythrocytes does not seem to occur, even with high virus loads in erythrocytes. In this study, gene expression profiling performed with high-density oligonucleotide microarray showed that PRV infection of erythrocytes induced a large panel of virus responsive genes. These involved interferon-regulated antiviral genes, as well as genes involved in antigen presentation via MHC class I. PRV infection also stimulated negative immune regulators. In contrast, a large number of immune genes expressed prior to infection were down-regulated. Moderate reduction of expression was also found for many genes encoding components of cytoskeleton and myofiber, proteins involved in metabolism, ion exchange, cell-cell interactions as well as growth factors and regulators of differentiation. PRV did not affect expression of genes involved in heme biosynthesis, gas exchange or erythrocyte-specific markers, but some regulators of erythropoiesis showed decreased transcription levels. These results indicate that PRV infection activates innate antiviral immunity in salmon erythrocytes, but suppresses other gene expression programs. Gene expression profiles suggest major phenotypic changes in PRV infected erythrocytes, but the functional consequences remain to be explored.
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Affiliation(s)
| | - Øystein Wessel
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Gerrit Timmerhaus
- Nofima AS, Norwegian Institutes of Food, Fisheries & Aquaculture Research, Ås, Norway
| | - Ingvild Berg Nyman
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Sven Martin Jørgensen
- Nofima AS, Norwegian Institutes of Food, Fisheries & Aquaculture Research, Ås, Norway
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Aleksei Krasnov
- Nofima AS, Norwegian Institutes of Food, Fisheries & Aquaculture Research, Ås, Norway.
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49
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Wessel Ø, Olsen CM, Rimstad E, Dahle MK. Piscine orthoreovirus (PRV) replicates in Atlantic salmon (Salmo salar L.) erythrocytes ex vivo. Vet Res 2015; 46:26. [PMID: 25888832 PMCID: PMC4350956 DOI: 10.1186/s13567-015-0154-7] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 01/26/2015] [Indexed: 12/22/2022] Open
Abstract
Piscine orthoreovirus (PRV) is a reovirus that has predominantly been detected in Atlantic salmon (Salmo salar L.). PRV is associated with heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon, and recently erythrocytes were identified as major target cells. The study of PRV replication and pathogenesis of the infection has been impeded by the inability to propagate PRV in vitro. In this study we developed an ex vivo cultivation system for PRV in Atlantic salmon erythrocytes. PRV was successfully passaged to naïve erythrocytes using lysates of blood cells from infected salmon. During cultivation a significant increase in viral load was observed by RT-qPCR and flow cytometry, which coincided with the formation of cytoplasmic inclusions. The inclusions resembled viral factories and contained both PRV protein and dsRNA. In addition, the erythrocytes generated an antiviral immune gene activation after PRV infection, with significant up-regulation of IFN-α, RIG-I, Mx and PKR transcripts. Supernatants from the first passage successfully transmitted virus to naïve erythrocytes. This study demonstrates that PRV replicates in Atlantic salmon erythrocytes ex vivo. The ex vivo infection model closely reflects the situation in vivo and can be used to study the infection and replication mechanisms of PRV, as well as the antiviral immune responses of salmonid erythrocytes.
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Affiliation(s)
- Øystein Wessel
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway.
| | - Christel Moræus Olsen
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway.
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway.
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50
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Abdullah A, Olsen CM, Hodneland K, Rimstad E. A polyprotein-expressing salmonid alphavirus replicon induces modest protection in atlantic salmon (Salmo salar) against infectious pancreatic necrosis. Viruses 2015; 7:252-67. [PMID: 25606973 PMCID: PMC4306837 DOI: 10.3390/v7010252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 01/13/2015] [Indexed: 12/17/2022] Open
Abstract
Vaccination is an important strategy for the control and prevention of infectious pancreatic necrosis (IPN) in farmed Atlantic salmon (Salmo salar) in the post-smolt stage in sea-water. In this study, a heterologous gene expression system, based on a replicon construct of salmonid alphavirus (SAV), was used for in vitro and in vivo expression of IPN virus proteins. The large open reading frame of segment A, encoding the polyprotein NH2-pVP2-VP4-VP3-COOH, as well as pVP2, were cloned and expressed by the SAV replicon in Chinook salmon embryo cells (CHSE-214) and epithelioma papulosum cyprini (EPC) cells. The replicon constructs pSAV/polyprotein (pSAV/PP) and pSAV/pVP2 were used to immunize Atlantic salmon (Salmo salar) by a single intramuscular injection and tested in a subsequent IPN virus (IPNV) challenge trial. A low to moderate protection against IPN was observed in fish immunized with the replicon vaccine that encoded the pSAV/PP, while the pSAV/pVP2 construct was not found to induce protection.
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Affiliation(s)
- Azila Abdullah
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, P.O. Box 8146 Dep, 0033 Oslo, Norway.
| | - Christel M Olsen
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, P.O. Box 8146 Dep, 0033 Oslo, Norway.
| | - Kjartan Hodneland
- MSD Animal Health Norway, Thormøhlensgate 55, N-5008 Bergen, Norway.
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, P.O. Box 8146 Dep, 0033 Oslo, Norway.
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