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Kumar A, Middha SK, Menon SV, Paital B, Gokarn S, Nelli M, Rajanikanth RB, Chandra HM, Mugunthan SP, Kantwa SM, Usha T, Hati AK, Venkatesan D, Rajendran A, Behera TR, Venkatesamurthy S, Sahoo DK. Current Challenges of Vaccination in Fish Health Management. Animals (Basel) 2024; 14:2692. [PMID: 39335281 PMCID: PMC11429256 DOI: 10.3390/ani14182692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Revised: 09/10/2024] [Accepted: 09/11/2024] [Indexed: 09/30/2024] Open
Abstract
Vaccination is an essential method of immunological preventive care required for the health management of all animals, including fish. More particularly, immunization is necessary for in-land aquaculture to manage diseases in fish broodstocks and healthy seed production. According to the latest statistics in 2020, 90.3 million tons of capture fishery production was achieved from the aquaculture sector. Out of the above, 78.8 million tons were from marine water aquaculture sectors, and 11.5 million tons were from inland water aquaculture sectors. About a 4% decline in fish production was achieved in 2020 in comparison to 2018 from inland aquaculture sectors. On the other hand, the digestive protein content, healthy fats, and nutritional values of fish products are comparatively more affordable than in other meat sources. In 2014, about 10% of aquatic cultured animals were lost (costing global annual losses > USD 10 billion) due to infectious diseases. Therefore, vaccination in fish, especially in broodstocks, is one of the essential approaches to stop such losses in the aquaculture sector. Fish vaccines consist of whole-killed pathogens, protein subunits, recombinant proteins, DNA, or live-attenuated vaccines. Challenges persist in the adaption of vaccination in the aquaculture sector, the route of administration, the use of effective adjuvants, and, most importantly, the lack of effective results. The use of autogenous vaccines; vaccination via intramuscular, intraperitoneal, or oral routes; and, most importantly, adding vaccines in feed using top dressing methods or as a constituent in fish feed are now emerging. These methods will lower the risk of using antibiotics in cultured water by reducing environmental contamination.
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Affiliation(s)
- Avnish Kumar
- Department of Biotechnology, School of Life Sciences, Dr. Bhimrao Ambedkar University, Agra 282004, India
| | - Sushil Kumar Middha
- Department of Biotechnology, Maharani Lakshmi Ammanni College for Women, 18th Cross, Malleswaram, Bangalore 560012, India
| | - Soumya Vettiyatil Menon
- Department of Chemistry and Biochemistry, School of Sciences, Jain University, #34 JC Road, Bangalore 560027, India
| | - Biswaranjan Paital
- Redox Regulation Laboratory, Department of Zoology, College of Basic Science and Humanities, Odisha University of Agriculture and Technology, Bhubaneswar 751003, India
| | - Shyam Gokarn
- Department of Chemistry and Biochemistry, School of Sciences, Jain University, #34 JC Road, Bangalore 560027, India
| | - Meghana Nelli
- Department of Chemistry and Biochemistry, School of Sciences, Jain University, #34 JC Road, Bangalore 560027, India
| | | | - Harish Mani Chandra
- Department of Biotechnology, Thiruvalluvar University, Serkkadu, Vellore 632115, India
| | | | - Sanwar Mal Kantwa
- Department of Zoology, B. S. Memorial P.G. College, NH 52, Ranoli, Sikar 332403, India
| | - Talambedu Usha
- Department of Biochemistry, Maharani Lakshmi Ammanni College for Women, 18th Cross, Malleswaram, Bangalore 560012, India
| | - Akshaya Kumar Hati
- Dr. Abhin Chandra Homoeopathic Medical College and Hospital, Homeopathic College Rd., Unit 3, Kharvela Nagar, Bhubaneswar 751001, India
| | | | - Abira Rajendran
- Department of Chemistry and Biochemistry, School of Sciences, Jain University, #34 JC Road, Bangalore 560027, India
| | - Tapas Ranjan Behera
- Department of Community Medicine, Fakir Mohan Medical College and Hospital, Januganj Rd., Kalidaspur, Balia, Balasore 756019, India
| | - Swarupa Venkatesamurthy
- Department of Chemistry and Biochemistry, School of Sciences, Jain University, #34 JC Road, Bangalore 560027, India
| | - Dipak Kumar Sahoo
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA;
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2
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Mordecai G, Di Cicco E, Deeg C, Bateman A, Teffer A, Miller K. Comment on a perspective: Molecular detections of new agents in finfish-Interpreting biological significance for fish health management. JOURNAL OF AQUATIC ANIMAL HEALTH 2024; 36:220-230. [PMID: 39042565 DOI: 10.1002/aah.10221] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 08/31/2023] [Accepted: 02/20/2024] [Indexed: 07/25/2024]
Abstract
Impact statementThe rapid development of genomic technologies has begun a new paradigm in the study and management of emerging infectious diseases. To inform the conservation of fish, here we examine different perspectives on how to determine thresholds for management action in the context of molecular tools and fisheries policy.
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Affiliation(s)
- Gideon Mordecai
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Christoph Deeg
- Pacific Salmon Foundation, Vancouver, British Columbia, Canada
- Fisheries and Oceans Canada, Pacific Biological Station, Nanaimo, British Columbia, Canada
| | - Andrew Bateman
- Pacific Salmon Foundation, Vancouver, British Columbia, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| | - Amy Teffer
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Kristi Miller
- Fisheries and Oceans Canada, Pacific Biological Station, Nanaimo, British Columbia, Canada
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3
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Vatne NA, Wessel Ø, Trengereid H, Haugsland S, Rimstad E, Stormoen M. Introduction and temporospatial tracing of piscine orthoreovirus-1 (PRV-1) in Norwegian farmed Atlantic salmon (Salmo salar) after local fallowing. JOURNAL OF FISH DISEASES 2024; 47:e13978. [PMID: 38840479 DOI: 10.1111/jfd.13978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 05/10/2024] [Accepted: 05/14/2024] [Indexed: 06/07/2024]
Abstract
Piscine orthoreovirus-1 (PRV-1) is a prevalent agent in Atlantic salmon (Salmo salar) and the causative agent of heart and skeletal muscle inflammation (HSMI), an important disease in farmed Atlantic salmon. Investigations into the introduction and dissemination routes of PRV-1 in a field setting have been limited. This study aimed to better understand PRV-1 infections and HSMI-associated mortality under field conditions. We tracked introduction and spread of PRV-1 over one production cycle in a geographically isolated region in Norwegian aquaculture. From five sites, a total of 32 virus isolates were sequenced and genogrouped. The results indicated multiple introductions of PRV-1 to the area, but also revealed a high level of genetic homogeneity among the virus variants. The variants differed from that of the previous production cycle at two out of three sites investigated, suggesting that synchronized fallowing can be a useful tool for preventing dissemination of PRV-1 between generations of fish. Exposure to PRV-1 at the freshwater stage was identified as a potential source of introduction. A low level of HSMI-associated mortality was observed at all sites, with the onset of mortality showing some variation across PRV-1 genogroups. However, the study highlighted the complexity of associating viral genogroups with mortality in a field setting. Overall, this study contributes valuable insights into PRV-1 dynamics in a real-world aquaculture setting, offering potential strategies for disease management and prevention.
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Affiliation(s)
- Nina A Vatne
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Øystein Wessel
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | | | | | - Espen Rimstad
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Marit Stormoen
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
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4
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Ivanova L, Rangel-Huerta OD, Tartor H, Dahle MK, Uhlig S, Fæste CK. Metabolomics and Multi-Omics Determination of Potential Plasma Biomarkers in PRV-1-Infected Atlantic Salmon. Metabolites 2024; 14:375. [PMID: 39057698 PMCID: PMC11279234 DOI: 10.3390/metabo14070375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 06/25/2024] [Accepted: 06/28/2024] [Indexed: 07/28/2024] Open
Abstract
Metabolomic analysis has been explored to search for disease biomarkers in humans for some time. The application to animal species, including fish, however, is still at the beginning. In the present study, we have used targeted and untargeted metabolomics to identify metabolites in the plasma of Atlantic salmon (Salmo salar) challenged with Piscine orthoreovirus (PRV-1), aiming to find metabolites associated with the progression of PRV-1 infection into heart and skeletal muscle inflammation (HSMI). The metabolomes of control and PRV-1-infected salmon were compared at three time points during disease development by employing different biostatistical approaches. Targeted metabolomics resulted in the determination of affected metabolites and metabolic pathways, revealing a substantial impact of PRV-1 infection on lipid homeostasis, especially on several (lyso)phosphatidylcholines, ceramides, and triglycerides. Untargeted metabolomics showed a clear separation of the treatment groups at later study time points, mainly due to effects on lipid metabolism pathways. In a subsequent multi-omics approach, we combined both metabolomics datasets with previously reported proteomics data generated from the same salmon plasma samples. Data processing with DIABLO software resulted in the identification of significant metabolites and proteins that were representative of the HSMI development in the salmon.
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Affiliation(s)
- Lada Ivanova
- Norwegian Veterinary Institute, P.O. Box 64, 1431 Ås, Norway; (O.D.R.-H.); (H.T.); (M.K.D.); (S.U.)
| | | | | | | | | | - Christiane Kruse Fæste
- Norwegian Veterinary Institute, P.O. Box 64, 1431 Ås, Norway; (O.D.R.-H.); (H.T.); (M.K.D.); (S.U.)
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5
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Bjørgen H, Brimsholm M, Lund M, Dahle MK, Rimstad E, Koppang EO. Red and melanized focal changes in the white skeletal muscle of farmed rainbow trout Oncorhynchus mykiss. DISEASES OF AQUATIC ORGANISMS 2024; 158:201-213. [PMID: 38934260 DOI: 10.3354/dao03797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
Fillet discoloration by red and melanized focal changes (RFCs and MFCs) is common in farmed Atlantic salmon Salmo salar. In farmed rainbow trout Oncorhynchus mykiss, similar changes have been noted, but their prevalence and histological characteristics have not been investigated. Thus, we conducted a study encompassing 1293 rainbow trout from 3 different farm sites in Norway, all examined at the time of slaughter. Both macroscopic and histological assessments of the changes were performed. Reverse transcription (RT)-qPCR analyses and in situ hybridization (ISH) were used to detect the presence and location, respectively, of potential viruses. Only 1 RFC was detected in a single fillet, while the prevalence of MFCs ranged from 1.46 to 6.47% between populations. The changes were predominantly localized in the cranioventral region of the fillet. Histological examinations unveiled necrotic myocytes, fibrosis, and regeneration of myocytes. Melano-macrophages were found in the affected areas and in myoseptal adipose tissue. Organized granulomas were observed in only 1 fish. Notably, the presence of inflammatory cells, including melano-macrophages, appeared lower compared to what has been previously documented in Atlantic salmon MFCs. Instead, fibrosis and regeneration dominated. RT-qPCR and ISH revealed the presence of piscine orthoreovirus 1 (PRV-1) and salmonid alphavirus (SAV) in skeletal muscle. However, these viruses were not consistently associated with lesioned areas, contrasting previous findings in Atlantic salmon. In conclusion, rainbow trout develop MFCs of a different character than farmed Atlantic salmon, and we speculate whether the observed pathological differences are contributing to their reduced occurrence in farmed rainbow trout.
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Affiliation(s)
- Håvard Bjørgen
- Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433 Ås, Norway
| | - Malin Brimsholm
- Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433 Ås, Norway
| | - Morten Lund
- Pure Salmon Kaldnes, 3241 Sandefjord, Norway
| | | | - Espen Rimstad
- Unit of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433 Ås, Norway
| | - Erling Olaf Koppang
- Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433 Ås, Norway
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6
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Takano T, Miwa S, Matsuyama T, Kiryu I, Honjo M, Sakai T, Matsuura Y, Yamasaki M, Kumagai A, Nakayasu C. Clinical symptoms and histopathological changes in coho salmon affected by the erythrocytic inclusion body syndrome (EIBS) are caused by the infection of piscine orthoreovirus 2 (PRV-2). JOURNAL OF FISH DISEASES 2024; 47:e13939. [PMID: 38481093 DOI: 10.1111/jfd.13939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 02/29/2024] [Accepted: 03/01/2024] [Indexed: 05/12/2024]
Abstract
The relationship of histopathological changes and the infection of Piscine orthoreovirus 2 (PRV-2) was investigated in coho salmon that were suffering from the erythrocytic inclusion body syndrome (EIBS). Immunohistochemical observations revealed abundant σ1 protein of PRV-2 in the spongy layer of the ventricle of the heart, where severe myocarditis was observed. In the spleen, the virus protein was detected in many erythrocytes, some of which were spherical-shaped and apparently dead. The number of erythrocytes was decreased in the spleen compared to the apparently healthy fish. The virus protein was also detected in some erythrocytes in blood vessels. The viral protein was often detected in many macrophages ingesting erythrocytes or dead cell debris in the spleen or in the kidney sinusoids. Large amounts of the viral genomic segment L2 were also detected in these organs by RT-qPCR. Many necrotic foci were found in the liver, although the virus protein was not detected in the hepatocytes. These results suggest that the primary targets of PRV-2 are myocardial cells and erythrocytes and that clinical symptoms such as anaemia or jaundice and histopathological changes such as myocarditis in EIBS-affected coho salmon are caused by PRV-2 infection.
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Affiliation(s)
- Tomokazu Takano
- Pathology Division, Aquaculture Research Department, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Minami-ise, Japan
| | - Satoshi Miwa
- Pathology Division, Aquaculture Research Department, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Minami-ise, Japan
| | - Tomomasa Matsuyama
- Pathology Division, Aquaculture Research Department, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Minami-ise, Japan
| | - Ikunari Kiryu
- Pathology Division, Aquaculture Research Department, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Minami-ise, Japan
| | - Miho Honjo
- Miyagi Prefecture Fisheries Technology Institute, Ishinomaki, Japan
| | - Takamitsu Sakai
- Pathology Division, Aquaculture Research Department, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Minami-ise, Japan
| | - Yuta Matsuura
- Pathology Division, Aquaculture Research Department, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Minami-ise, Japan
| | - Masatoshi Yamasaki
- Pathology Division, Aquaculture Research Department, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Minami-ise, Japan
| | - Akira Kumagai
- Miyagi Prefecture Fisheries Technology Institute, Ishinomaki, Japan
| | - Chihaya Nakayasu
- Pathology Division, Aquaculture Research Department, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Minami-ise, Japan
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7
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Eckstrand CD, Torrevillas BK, Wolking RM, Bradway DS, Reno JL, McMenamin-Snekvik KM, Snekvik KR. Detection, sequencing, and tissue distribution of piscine orthoreovirus 2-like virus in diseased coho salmon in Alaska. J Vet Diagn Invest 2024; 36:338-345. [PMID: 38693675 PMCID: PMC11110780 DOI: 10.1177/10406387241250119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024] Open
Abstract
We performed a diagnostic disease investigation on a cohort of coho salmon (Oncorhynchus kisutch) fingerlings in Alaska exhibiting anorexia, gaping mouths, anemia, and increased mortality. Histologic examination revealed mild-to-severe myocardial degeneration and lymphohistiocytic and neutrophilic myocarditis, moderate splenic histiocytosis, and mild renal histiocytosis. Piscine orthoreoviruses 1 and 3 were not detected by molecular methods, and no other viruses could be cultured on 3 common diagnostic fish cell lines. De novo assembly produced a viral genome of 10 linear segments with >80% homology to piscine orthoreovirus 2 (PRV2) encoding all 11 PRV2 proteins. An in situ hybridization probe using RNAscope was developed against 697 viral nucleotides identified by sequencing, which revealed viral genome in heart, spleen, gill, kidney, liver, blood, and the lamina propria of the intestines. Our findings are supportive of a novel piscine orthoreovirus most closely related to PRV2 associated with morbidity and mortality of coho salmon in the northeastern Pacific.
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Affiliation(s)
- Chrissy D. Eckstrand
- Washington Animal Disease Diagnostic Laboratory, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - Brandi K. Torrevillas
- Washington Animal Disease Diagnostic Laboratory, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - Rebecca M. Wolking
- Washington Animal Disease Diagnostic Laboratory, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - Daniel S. Bradway
- Washington Animal Disease Diagnostic Laboratory, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - Joetta Lynn Reno
- Washington Animal Disease Diagnostic Laboratory, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - Kathleen M. McMenamin-Snekvik
- Washington Animal Disease Diagnostic Laboratory, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - Kevin R. Snekvik
- Washington Animal Disease Diagnostic Laboratory, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
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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] [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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9
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Madhun AS, Nilsen R, Barlaup BT, Karlsen Ø, Karlsbakk E. Occurrence of salmonid alphavirus and piscine orthoreovirus-1 infections in migrating salmon (Salmo salar L.) post-smolt in western Norway. JOURNAL OF FISH DISEASES 2024; 47:e13874. [PMID: 37828712 DOI: 10.1111/jfd.13874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/29/2023] [Accepted: 10/03/2023] [Indexed: 10/14/2023]
Abstract
Viral diseases are a serious problem in Atlantic salmon (Salmo salar L.) farming in Norway, often leading to reduced fish welfare and increased mortality. Disease outbreaks in salmon farms may lead to spread of viruses to the surrounding environment. There is a public concern that viral diseases may negatively affect the wild salmon populations. Pancreas disease (PD) caused by salmonid alphavirus (SAV) and heart and skeletal muscle inflammation (HSMI) caused by piscine orthoreovirus-1 (PRV-1) are common viral diseases in salmon farms in western Norway. In the current study, we investigated the occurrence of SAV and PRV-1 infections in 651 migrating salmon post-smolt collected from three fjord systems (Sognefjorden, Osterfjorden and Hardangerfjorden) located in western Norway in 2013 and 2014 by real-time RT-PCR. Of the collected post-smolts, 303 were of wild origin and 348 were hatchery-released. SAV was not detected in any of the tested post-smolt, but PRV-1 was detected in 4.6% of them. The Ct values of PRV-1 positive fish were usually high (mean 32.0; range: 20.1-36.8). PRV-1 prevalence in post-smolts from the three fjords was 6.1% in Sognefjorden followed by 4.8% in Osterfjorden and 2.3% in Hardangerfjorden. The prevalence PRV-1 was significantly higher in wild (6.9%) compared to hatchery-released post-smolt (2.6%). The occurrence of PRV-1 infection in the fish was lowest in the Hardangerfjorden which has the highest fish farming intensity. Our results suggest that SAV infection are uncommon in migrating smolt while PRV-1 infection can be detected at low level. These findings suggest that migrating smolts were at low risk from SAV or PRV-1 released from salmon farms located in their migration routes in 2013 and 2014.
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Affiliation(s)
| | - Rune Nilsen
- Institute of Marine Research, Bergen, Norway
| | - Bjørn T Barlaup
- Laboratory for Freshwater Ecology and Inland Fisheries, NORCE Norwegian Research Centre, Bergen, Norway
| | | | - Egil Karlsbakk
- Institute of Marine Research, Bergen, Norway
- Department of Biological Sciences, University of Bergen, Bergen, Norway
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Brimsholm M, Fjelldal PG, Hansen T, Fraser TKW, Solberg M, Glover K, Koppang EO, Bjørgen H. Red and melanized focal changes in white skeletal muscle in Atlantic salmon (Salmo salar): Comparative analysis of farmed, wild and hybrid fish reared under identical conditions. JOURNAL OF FISH DISEASES 2023; 46:1377-1389. [PMID: 37675872 DOI: 10.1111/jfd.13856] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/16/2023] [Accepted: 08/22/2023] [Indexed: 09/08/2023]
Abstract
Selective breeding plays a vital role in the production of farmed Atlantic salmon and has shown success in many aspects. Still, challenges related to fish health and welfare continue to result in significant economic losses. One such challenge is red and melanized focal changes (RFC/MFC), which result from acute and chronic inflammation, respectively, in the skeletal muscle. Importantly, RFC/MFC has not been observed in wild Atlantic salmon, suggesting that both external and genetic factors may contribute to the development of inflammation. To investigate the underlying cause of RFC/MFC, we conducted a study involving 1854 Atlantic salmon of farmed, wild and hybrid origin. All fish were reared under identical conditions to minimize the influence of external factors. Throughout the production cycle, the fish was monitored for growth parameters and examined for RFC/MFC using macroscopic and histological analysis. We found no association between the experimental groups and the presence of RFC/MFC. Histological investigations revealed melano-macrophages in the soft tissue in freshwater smolt, although no macroscopic discoloration was observed. MFC showed granulomas in various stages, suggesting a complex progression of the condition. In summary, we conclude that RFC/MFC is primarily caused by external factors found in the rearing facilities of farmed Atlantic salmon.
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Affiliation(s)
- Malin Brimsholm
- Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | | | - Tom Hansen
- Matre Research Station, Institute of Marine Research, Matredal, Norway
| | | | - Monica Solberg
- Population Genetics Research Group, Institute of Marine Research, Bergen, Norway
| | - Kevin Glover
- Population Genetics Research Group, Institute of Marine Research, Bergen, 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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11
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Kannimuthu D, Roh H, Peñaranda MMD, Wessel Ø, Mæhle S, Berhe GD, Nordbø J, Kvamme BO, Morton HC, Grove S. Long-term persistence of piscine orthoreovirus-1 (PRV-1) infection during the pre-smolt stages of Atlantic salmon in freshwater. Vet Res 2023; 54:69. [PMID: 37644605 PMCID: PMC10463814 DOI: 10.1186/s13567-023-01201-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 07/07/2023] [Indexed: 08/31/2023] Open
Abstract
Piscine orthoreovirus (PRV) causes heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon. During salmon production cycles, HSMI has predominantly been observed after seawater transfer. More recently, better surveillance and longitudinal studies have detected occurrences of PRV-1 in freshwater broodstock farms and hatcheries. However, very little is known about the viral kinetics of PRV-1 or disease development of HSMI during these pre-smolt stages. In this study, we conducted a long-term PRV-1 challenge experiment to examine the profile of viral load, infectiousness and/or clearance in Atlantic salmon during their development from fry to parr stage. Atlantic salmon fry (mean weight: 1.1 ± 0.19 g) were infected with PRV-1 (high virulent variant) via intraperitoneal (IP) injection. The viral load reached a peak at 2-4 weeks post-challenge (wpc) in heart and muscle tissues. The virus was detected at relatively high levels in whole blood, spleen, and head kidney tissues until 65 wpc. Heart and muscle lesions typical of HSMI were clearly observed at 6 and 8 wpc but then subsided afterwards resolving inflammation. Innate and adaptive immune responses were elicited during the early/acute phase but returned to basal levels during the persistent phase of infection. Despite achieving high viremia, PRV-1 infection failed to cause any mortality during the 65-week virus challenge period. Cohabitation of PRV-1 infected fish (10 and 31 wpc) with naïve Atlantic salmon fry resulted in very low or no infection. Moreover, repeated chasing stress exposures did not affect the viral load or shedding of PRV-1 at 26 and 44 wpc. The present findings provide knowledge about PRV-1 infection in juvenile salmon and highlight the importance of continued monitoring and management to prevent and mitigate the PRV-1 infection in freshwater facilities.
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Affiliation(s)
| | - HyeongJin Roh
- Institute of Marine Research, Nordnes, P.O. Box 1870, N-5817, Bergen, Norway
| | | | - Øystein Wessel
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433, Ås, Norway
| | - Stig Mæhle
- Institute of Marine Research, Nordnes, P.O. Box 1870, N-5817, Bergen, Norway
| | | | - Joachim Nordbø
- Institute of Marine Research, Nordnes, P.O. Box 1870, N-5817, Bergen, Norway
| | - Bjørn Olav Kvamme
- Institute of Marine Research, Nordnes, P.O. Box 1870, N-5817, Bergen, Norway
| | - H Craig Morton
- Institute of Marine Research, Nordnes, P.O. Box 1870, N-5817, Bergen, Norway
| | - Søren Grove
- Institute of Marine Research, Nordnes, P.O. Box 1870, N-5817, Bergen, Norway
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12
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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.). JOURNAL OF FISH DISEASES 2023; 46:453-458. [PMID: 36353756 DOI: 10.1111/jfd.13729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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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13
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Sørensen J, Cuenca A, Olsen AB, Skovgaard K, Iburg TM, Olesen NJ, Vendramin N. Decreased water temperature enhance Piscine orthoreovirus genotype 3 replication and severe heart pathology in experimentally infected rainbow trout. Front Vet Sci 2023; 10:1112466. [PMID: 36846252 PMCID: PMC9950551 DOI: 10.3389/fvets.2023.1112466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/25/2023] [Indexed: 02/12/2023] Open
Abstract
Piscine orthoreovirus genotype 3 (PRV-3) was first discovered in Denmark in 2017 in relation to disease outbreaks in rainbow trout (Oncorhynchus mykiss). While the virus appears to be widespread in farmed rainbow trout, disease outbreaks associated with detection of PRV-3 have only occurred in recirculating aquaculture systems, and has predominantly been observed during the winter months. To explore the possible effects of water temperature on PRV-3 infection in rainbow trout, an in vivo cohabitation trial was conducted at 5, 12, and 18°C. For each water temperature, a control tank containing mock-injected shedder fish and a tank with PRV-3 exposed fish were included. Samples were collected from all experimental groups every 2nd week post challenge (WPC) up until trial termination at 12 WPC. PRV-3 RNA load measured in heart tissue of cohabitants peaked at 6 WPC for animals maintained at 12 and 18°C, while it reached its peak at 12 WPC in fish maintained at 5°C. In addition to the time shift, significantly more virus was detected at the peak in fish maintained at 5°C compared to 12 and 18°C. In shedders, fish at 12 and 18°C cleared the infection considerably faster than the fish at 5°C: while shedders at 18 and 12°C had cleared most of the virus at 4 and 6 WPC, respectively, high virus load persisted in the shedders at 5°C until 12 WPC. Furthermore, a significant reduction in the hematocrit levels was observed in the cohabitants at 12°C in correlation with the peak in viremia at 6 WPC; no changes in hematocrit was observed at 18°C, while a non-significant reduction (due to large individual variation) trend was observed at cohabitants held at 5°C. Importantly, isg15 expression was positively correlated with PRV-3 virus load in all PRV-3 exposed groups. Immune gene expression analysis showed a distinct gene profile in PRV-3 exposed fish maintained at 5°C compared to 12 and 18°C. The immune markers mostly differentially expressed in the group at 5°C were important antiviral genes including rigi, ifit5 and rsad2 (viperin). In conclusion, these data show that low water temperature allow for significantly higher PRV-3 replication in rainbow trout, and a tendency for more severe heart pathology development in PRV-3 injected fish. Increased viral replication was mirrored by increased expression of important antiviral genes. Despite no mortality being observed in the experimental trial, the data comply with field observations of clinical disease outbreaks during winter and cold months.
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Affiliation(s)
- Juliane Sørensen
- Section for Fish and Shellfish Diseases, National Institute for Aquatic Resources, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Argelia Cuenca
- Section for Fish and Shellfish Diseases, National Institute for Aquatic Resources, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Anne Berit Olsen
- Section of Aquatic Biosecurity Research, Norwegian Veterinary Institute, Bergen, Norway
| | - Kerstin Skovgaard
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Tine Moesgaard Iburg
- Section for Fish and Shellfish Diseases, National Institute for Aquatic Resources, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Niels Jørgen Olesen
- Section for Fish and Shellfish Diseases, National Institute for Aquatic Resources, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Niccolò Vendramin
- Section for Fish and Shellfish Diseases, National Institute for Aquatic Resources, Technical University of Denmark, Kgs. Lyngby, Denmark,*Correspondence: Niccolò Vendramin ✉
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14
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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] [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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15
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Polinski MP, Gross LA, Marty GD, Garver KA. Heart inflammation and piscine orthoreovirus genotype-1 in Pacific Canada Atlantic salmon net-pen farms: 2016-2019. BMC Vet Res 2022; 18:306. [PMID: 35948980 PMCID: PMC9364591 DOI: 10.1186/s12917-022-03409-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/27/2022] [Indexed: 11/25/2022] Open
Abstract
Piscine orthoreovirus genotype-1 (PRV-1) is a virus commonly associated with Atlantic salmon aquaculture with global variability in prevalence and association with disease. From August 2016 to November 2019, 2,070 fish sampled at 64 Atlantic salmon net-pen farm sites during 302 sampling events from British Columbia, Canada, were screened for PRV-1 using real-time qPCR. Nearly all populations became PRV-1 positive within one year of seawater entry irrespective of location, time of stocking, or producer. Cohorts became infected between 100–300 days at sea in > 90% of repeatedly sampled sites and remained infected until harvest (typically 500–700 days at sea). Heart inflammation, which is sometimes attributed to PRV-1, was also assessed in 779 production mortalities from 47 cohorts with known PRV status. Mild heart inflammation was common in mortalities from both PRV + and PRV- populations (67% and 68% prevalence, respectively). Moderate and severe lymphoplasmacytic heart inflammation was rare (11% and 3% prevalence, respectively); however, mainly arose (66 of 77 occurrences) in populations with PRV-1. Detection of PRV-1 RNA was also accomplished in water and sediment for which methods are described. These data cumulatively identify that PRV-1 ubiquitously infects farmed Atlantic salmon in British Columbia during seawater production but only in rare instances correlates with heart inflammation.
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Affiliation(s)
- Mark P Polinski
- Fisheries and Oceans, Canada Pacific Biological Station, 3190 Hammond Bay Road, Nanaimo, V9T6N7, Canada. .,U.S. Department of Agriculture National Coldwater Marine Aquaculture Center, Portage Rd, Orono, ME, 04469, USA.
| | - Lynden A Gross
- Fisheries and Oceans, Canada Pacific Biological Station, 3190 Hammond Bay Road, Nanaimo, V9T6N7, Canada
| | - Gary D Marty
- Animal Health Centre, Ministry of Agriculture and Food, 1767 Angus Campbell Rd, Abbotsford, V3G2M3, Canada
| | - Kyle A Garver
- Fisheries and Oceans, Canada Pacific Biological Station, 3190 Hammond Bay Road, Nanaimo, V9T6N7, Canada
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16
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Meyers TR, Hickey N. A Perspective: Molecular Detections of New Agents in Finfish-Interpreting Biological Significance for Fish Health Management. JOURNAL OF AQUATIC ANIMAL HEALTH 2022; 34:47-57. [PMID: 35384072 DOI: 10.1002/aah.10155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 12/31/2021] [Accepted: 03/31/2022] [Indexed: 06/14/2023]
Abstract
The increased sensitivity of advanced molecular techniques greatly exceeds the sensitivities of traditional detection methods for infectious agents. This sensitivity causes difficulty in interpreting the biological significance of such detections in fish (and shellfish), especially when the agent(s) cannot be cultured in the laboratory. In the Pacific Northwest, including Canada and Alaska, molecular detections of "new" (unknown or known but discovered in a different geographic location or fish host) potentially infectious agents in fish have received extensive media attention and misinterpretation that call for resource agencies to change current fish health surveillance practices or policies to include these agents. Fish health specialists from several of these agencies and organizations (see Acknowledgments) advise that any policy changes should be made only after further investigations to avoid wasting resources to conduct surveillance for organisms that are not significant to fish health or for noninfectious genetic material that does not represent a viable agent. Molecular detection is not proof of agent viability within or on host tissues and requires further investigation regarding the agent's ability to replicate and evidence that the agent causes substantial risk of disease to exposed fish populations. This document provides examples of molecularly detected agents causing public concern that were accompanied by little or no data to provide context and assessment of biological significance, highlights important questions to be answered regarding these detections, and provides a suggested pathway of investigative criteria to determine viability and pathogenicity of such agents that are necessary for consideration of any changes to aquatic animal health practices and policies.
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Affiliation(s)
- Theodore R Meyers
- Alaska Department of Fish and Game, Commercial Fisheries Division, Post Office Box 115526, Juneau, Alaska, 99811, USA
| | - Nora Hickey
- Northwest Indian Fisheries Commission, 6730 Martin Way East, Olympia, Washington, 98516, USA
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17
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Vallejos-Vidal E, Reyes-López FE, Sandino AM, Imarai M. Sleeping With the Enemy? The Current Knowledge of Piscine Orthoreovirus (PRV) Immune Response Elicited to Counteract Infection. Front Immunol 2022; 13:768621. [PMID: 35464421 PMCID: PMC9019227 DOI: 10.3389/fimmu.2022.768621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 02/25/2022] [Indexed: 11/13/2022] Open
Abstract
Piscine orthoreovirus (PRV) is a virus in the genus Orthoreovirus of the Reoviridae family, first described in 2010 associated with Heart and Skeletal Muscle Inflammation (HSMI) in Atlantic salmon (Salmo salar). Three phases of PRV infection have been described, the early entry and dissemination, the acute dissemination phase, and the persistence phase. Depending on the PRV genotype and the host, infection can last for life. Mechanisms of immune response to PRV infection have been just beginning to be studied and the knowledge in this matter is here revised. PRV induces a classical antiviral immune response in experimental infection of salmonid erythrocytes, including transcriptional upregulation of ifn-α, rig-i, mx, and pkr. In addition, transcript upregulation of tcra, tcrb, cd2, il-2, cd4-1, ifn-γ, il-12, and il-18 has been observed in Atlantic salmon infected with PRV, indicating that PRV elicited a Th1 type response probably as a host defense strategy. The high expression levels of cd8a, cd8b, and granzyme-A in PRV-infected fish suggest a positive modulatory effect on the CTL-mediated immune response. This is consistent with PRV-dependent upregulation of the genes involved in antigen presentation, including MHC class I, transporters, and proteasome components. We also review the potential immune mechanisms associated with the persistence phenotype of PRV-infected fish and its consequence for the development of a secondary infection. In this scenario, the application of a vaccination strategy is an urgent and challenging task due to the emergence of this viral infection that threatens salmon farming.
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Affiliation(s)
- Eva Vallejos-Vidal
- Centro de Biotecnología Acuícola, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile.,Facultad de Medicina Veterinaria y Agronomía, Universidad de Las Américas, Santiago, Chile
| | - Felipe E Reyes-López
- Centro de Biotecnología Acuícola, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile.,Department of Cell Biology, Physiology, and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Ana María Sandino
- Centro de Biotecnología Acuícola, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile.,Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Mónica Imarai
- Centro de Biotecnología Acuícola, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile.,Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
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18
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Zhao J, Vendramin N, Cuenca A, Polinski M, Hawley LM, Garver KA. Pan-Piscine Orthoreovirus (PRV) Detection Using Reverse Transcription Quantitative PCR. Pathogens 2021; 10:pathogens10121548. [PMID: 34959503 PMCID: PMC8707331 DOI: 10.3390/pathogens10121548] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/22/2021] [Accepted: 11/25/2021] [Indexed: 11/16/2022] Open
Abstract
Piscine orthoreovirus (PRV) infects farmed and wild salmon and trout species in North America, South America, Europe, and East Asia. PRV groups into three distinct genotypes (PRV-1, PRV-2, and PRV-3) that can vary in distribution, host specificity, and/or disease potential. Detection of the virus is currently restricted to genotype specific assays such that surveillance programs require the use of three assays to ensure universal detection of PRV. Consequently, herein, we developed, optimized, and validated a real-time reverse transcription quantitative PCR assay (RT-qPCR) that can detect all known PRV genotypes with high sensitivity and specificity. Targeting a conserved region at the 5′ terminus of the M2 segment, the pan-PRV assay reliably detected all PRV genotypes with as few as five copies of RNA. The assay exclusively amplifies PRV and does not cross-react with other salmonid viruses or salmonid host genomes and can be performed as either a one- or two-step RT-qPCR. The assay is highly reproducible and robust, showing 100% agreement in test results from an inter-laboratory comparison between two laboratories in two countries. Overall, as the assay provides a single test to achieve highly sensitive pan-specific PRV detection, it is suitable for research, diagnostic, and surveillance purposes.
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Affiliation(s)
- Julie Zhao
- Pacific Biological Station, Department of Fisheries and Oceans, Nanaimo, BC V9T 6N7, Canada; (J.Z.); (M.P.); (L.M.H.)
| | - Niccolò Vendramin
- Unit for Fish and Shellfish Diseases, National Institute of Aquatic Resources, Technical University of Denmark, 2800 Lyngby-Taarbæk, Denmark; (N.V.); (A.C.)
| | - Argelia Cuenca
- Unit for Fish and Shellfish Diseases, National Institute of Aquatic Resources, Technical University of Denmark, 2800 Lyngby-Taarbæk, Denmark; (N.V.); (A.C.)
| | - Mark Polinski
- Pacific Biological Station, Department of Fisheries and Oceans, Nanaimo, BC V9T 6N7, Canada; (J.Z.); (M.P.); (L.M.H.)
| | - Laura M. Hawley
- Pacific Biological Station, Department of Fisheries and Oceans, Nanaimo, BC V9T 6N7, Canada; (J.Z.); (M.P.); (L.M.H.)
| | - Kyle A. Garver
- Pacific Biological Station, Department of Fisheries and Oceans, Nanaimo, BC V9T 6N7, Canada; (J.Z.); (M.P.); (L.M.H.)
- Correspondence:
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19
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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] [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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20
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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: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [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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21
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Jiang X, Hu Y, Qu XP, Xu DW, Jiang H, Li CM, Jiang H, Wang DL, Li G, Zhu XG, Liu B. Prediction of in-hospital recurrence and false-negative results in patients with COVID-19 by red blood cell values on admission. Exp Ther Med 2021; 22:1250. [PMID: 34539846 PMCID: PMC8438694 DOI: 10.3892/etm.2021.10685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 04/26/2021] [Indexed: 01/08/2023] Open
Abstract
The clinical characteristics and risk factors of patients with coronavirus disease 2019 (COVID-19) with re-positive or false-negative test results have so far remained to be determined. The present study provides a cross-sectional observational study on 134 hospitalized patients selected from Huoshenshan Hospital (Wuhan, China) using cluster sampling. A total of 68 patients had reduced red blood cell (RBC) counts, 55 a decrease in the hemoglobin concentration (HBC) and 73 a decline in hematocrit (HCT). The false-negative rate of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) RNA detection in pharyngeal swab specimens was 18.7%. The absolute lymphocyte count (ALC), RBC, HBC and HCT levels in false-negative patients were significantly higher than those in patients who tested positive for viral nucleic acids. Multivariate logistic regression analysis indicated that RBC [odds ratio (OR)=0.43, 95% CI: 0.18-0.99], HBC (OR=0.97, 95% CI: 0.94-0.99) and ALC (OR=0.43, 95% CI: 0.20-0.91) were the factors influencing the negative testing results for viral nucleic acid. The rate of re-positive patients was 16.4%. The white blood cell, RBC, HBC and HCT values in re-positive patients were lower than those in non-re-positive patients. The median (interquartile range) values for RBC, HBC and HCT of male re-positive patients were 3.95 (3.37, 4.2) x1012/l, 123 (103, 133) g/l and 36.6 (31.1, 39.2)%, respectively, while the RBC, HBC and HCT of female re-positive patients were 3.54 (3.13, 3.74) x1012/l, 115 (102, 118) g/l and 34.2 (28.5, 34.9)%, respectively. It was determined that RBC, HBC and HCT values had moderate accuracy in predicting SARS-CoV-2 recurrence in patients with COVID-19 using receiver operating curve analysis. The present study suggested that RBC may have an important role in the pathogenesis of COVID-19.
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Affiliation(s)
- Xue Jiang
- Third Department of Infectious Diseases, Huoshenshan Hospital, Joint Logistics Support Force of The Chinese People's Liberation Army, Wuhan, Hubei 430101, P.R. China.,Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shanxi 710038, P.R. China
| | - Yan Hu
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shanxi 710038, P.R. China.,Department of Neurosurgery, The Second Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330008, P.R. China
| | - Xiao-Peng Qu
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shanxi 710038, P.R. China
| | - Dong-Wei Xu
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shanxi 710038, P.R. China
| | - Hong Jiang
- Third Department of Infectious Diseases, Huoshenshan Hospital, Joint Logistics Support Force of The Chinese People's Liberation Army, Wuhan, Hubei 430101, P.R. China.,Department of Infectious Diseases, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shanxi 710038, P.R. China
| | - Chun-Mei Li
- Third Department of Infectious Diseases, Huoshenshan Hospital, Joint Logistics Support Force of The Chinese People's Liberation Army, Wuhan, Hubei 430101, P.R. China.,Department of Respiratory Medicine, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shanxi 710038, P.R. China
| | - Hua Jiang
- Third Department of Infectious Diseases, Huoshenshan Hospital, Joint Logistics Support Force of The Chinese People's Liberation Army, Wuhan, Hubei 430101, P.R. China.,Department of Respiratory Medicine, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shanxi 710038, P.R. China
| | - Da-Li Wang
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shanxi 710038, P.R. China
| | - Gang Li
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shanxi 710038, P.R. China
| | - Xin-Gen Zhu
- Department of Neurosurgery, The Second Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330008, P.R. China
| | - Bei Liu
- Third Department of Infectious Diseases, Huoshenshan Hospital, Joint Logistics Support Force of The Chinese People's Liberation Army, Wuhan, Hubei 430101, P.R. China.,Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shanxi 710038, P.R. China
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22
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Polinski MP, Zhang Y, Morrison PR, Marty GD, Brauner CJ, Farrell AP, Garver KA. Innate antiviral defense demonstrates high energetic efficiency in a bony fish. BMC Biol 2021; 19:138. [PMID: 34253202 PMCID: PMC8276435 DOI: 10.1186/s12915-021-01069-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 06/09/2021] [Indexed: 11/18/2022] Open
Abstract
Background Viruses can impose energetic demands on organisms they infect, in part by hosts mounting resistance. Recognizing that oxygen uptake reliably indicates steady-state energy consumption in all vertebrates, we comprehensively evaluated oxygen uptake and select transcriptomic messaging in sockeye salmon challenged with either a virulent rhabdovirus (IHNV) or a low-virulent reovirus (PRV). We tested three hypotheses relating to the energetic costs of viral resistance and tolerance in this vertebrate system: (1) mounting resistance incurs a metabolic cost or limitation, (2) induction of the innate antiviral interferon system compromises homeostasis, and (3) antiviral defenses are weakened by acute stress. Results IHNV infections either produced mortality within 1–4 weeks or the survivors cleared infections within 1–9 weeks. Transcription of three interferon-stimulated genes (ISGs) was strongly correlated with IHNV load but not respiratory performance. Instead, early IHNV resistance was associated with a mean 19% (95% CI = 7–31%; p = 0.003) reduction in standard metabolic rate. The stress of exhaustive exercise did not increase IHNV transcript loads, but elevated host inflammatory transcriptional signaling up to sevenfold. For PRV, sockeye tolerated high-load systemic PRV blood infections. ISG transcription was transiently induced at peak PRV loads without associated morbidity, microscopic lesions, or major changes in aerobic or anaerobic respiratory performance, but some individuals with high-load blood infections experienced a transient, minor reduction in hemoglobin concentration and increased duration of excess post-exercise oxygen consumption. Conclusions Contrary to our first hypothesis, effective resistance against life-threatening rhabdovirus infections or tolerance to high-load reovirus infections incurred minimal metabolic costs to salmon. Even robust systemic activation of the interferon system did not levy an allostatic load sufficient to compromise host homeostasis or respiratory performance, rejecting our second hypothesis that this ancient innate vertebrate antiviral defense is itself energetically expensive. Lastly, an acute stress experienced during testing did not weaken host antiviral defenses sufficiently to promote viral replication; however, a possibility for disease intensification contingent upon underlying inflammation was indicated. These data cumulatively demonstrate that fundamental innate vertebrate defense strategies against potentially life-threatening viral exposure impose limited putative costs on concurrent aerobic or energetic demands of the organism. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01069-2.
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Affiliation(s)
- Mark P Polinski
- Fisheries and Oceans Canada Pacific Biological Station, 3190 Hammond Bay Road, Nanaimo, V9T6N7, Canada.
| | - Yangfan Zhang
- Faculty of Land and Food Systems, University of British Columbia, MCML 344-2357 Main Mall, Vancouver, V6T1Z4, Canada
| | - Phillip R Morrison
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, V6T1Z4, Canada
| | - Gary D Marty
- Animal Health Centre, Ministry of Agriculture, Food and Fisheries, 1767 Angus Campbell Rd, Abbotsford, V3G2M3, Canada
| | - Colin J Brauner
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, V6T1Z4, Canada
| | - Anthony P Farrell
- Faculty of Land and Food Systems, University of British Columbia, MCML 344-2357 Main Mall, Vancouver, V6T1Z4, Canada.,Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, V6T1Z4, Canada
| | - Kyle A Garver
- Fisheries and Oceans Canada Pacific Biological Station, 3190 Hammond Bay Road, Nanaimo, V9T6N7, Canada.
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23
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Yang L, Su J. Type II Grass Carp Reovirus Infects Leukocytes but Not Erythrocytes and Thrombocytes in Grass Carp ( Ctenopharyngodon idella). Viruses 2021; 13:v13050870. [PMID: 34068469 PMCID: PMC8150784 DOI: 10.3390/v13050870] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/07/2021] [Accepted: 05/08/2021] [Indexed: 01/25/2023] Open
Abstract
Grass carp reovirus (GCRV) causes serious losses to the grass carp industry. At present, infectious tissues of GCRV have been studied, but target cells remain unclear. In this study, peripheral blood cells were isolated, cultured, and infected with GCRV. Using quantitative real-time polymerase chain reaction (qRT-PCR), Western Blot, indirect immunofluorescence, flow cytometry, and transmission electron microscopy observation, a model of GCRV infected blood cells in vitro was established. The experimental results showed GCRV could be detectable in leukocytes only, while erythrocytes and thrombocytes could not. The virus particles in leukocytes are wrapped by empty membrane vesicles that resemble phagocytic vesicles. The empty membrane vesicles of leukocytes are different from virus inclusion bodies in C. idella kidney (CIK) cells. Meanwhile, the expression levels of IFN1, IL-1β, Mx2, TNFα were significantly up-regulated in leukocytes, indicating that GCRV could cause the production of the related immune responses. Therefore, GCRV can infect leukocytes in vitro, but not infect erythrocytes and thrombocytes. Leukocytes are target cells in blood cells of GCRV infections. This study lays a theoretical foundation for the study of the GCRV infection mechanism and anti-GCRV immunity.
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Affiliation(s)
- Ling Yang
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China;
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266237, China
- Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, China
| | - Jianguo Su
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China;
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266237, China
- Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, China
- Correspondence: ; Tel./Fax: +86-27-8728-2227
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24
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Mordecai GJ, Miller KM, Bass AL, Bateman AW, Teffer AK, Caleta JM, Di Cicco E, Schulze AD, Kaukinen KH, Li S, Tabata A, Jones BR, Ming TJ, Joy JB. Aquaculture mediates global transmission of a viral pathogen to wild salmon. SCIENCE ADVANCES 2021; 7:7/22/eabe2592. [PMID: 34039598 PMCID: PMC8153721 DOI: 10.1126/sciadv.abe2592] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 04/07/2021] [Indexed: 05/07/2023]
Abstract
Global expansion of aquaculture and agriculture facilitates disease emergence and catalyzes transmission to sympatric wildlife populations. The health of wild salmon stocks critically concerns Indigenous peoples, commercial and recreational fishers, and the general public. Despite potential impact of viral pathogens such as Piscine orthoreovirus-1 (PRV-1) on endangered wild salmon populations, their epidemiology in wild fish populations remains obscure, as does the role of aquaculture in global and local spread. Our phylogeographic analyses of PRV-1 suggest that development of Atlantic salmon aquaculture facilitated spread from Europe to the North and South East Pacific. Phylogenetic analysis and reverse transcription polymerase chain reaction surveillance further illuminate the circumstances of emergence of PRV-1 in the North East Pacific and provide strong evidence for Atlantic salmon aquaculture as a source of infection in wild Pacific salmon. PRV-1 is now an important infectious agent in critically endangered wild Pacific salmon populations, fueled by aquacultural transmission.
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Affiliation(s)
- Gideon J Mordecai
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
| | - Kristina M Miller
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada.
- Department of Forest and Conservation Sciences, Forest Sciences Centre, 3041 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada
| | - Arthur L Bass
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Andrew W Bateman
- Pacific Salmon Foundation, 1682 W 7th Ave., Vancouver, BC V6J 4S6, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Room 3055, Toronto, ON M5S 3B2, Canada
- Salmon Coast Field Station General Delivery, Simoom Sound, BC V0P 1S0, Canada
| | - Amy K Teffer
- David H. Smith Conservation Research Fellowship, Society for Conservation Biology, Washington, DC, USA
| | - Jessica M Caleta
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Emiliano Di Cicco
- Pacific Salmon Foundation, 1682 W 7th Ave., Vancouver, BC V6J 4S6, Canada
| | - Angela D Schulze
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Karia H Kaukinen
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Shaorong Li
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Amy Tabata
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Brad R Jones
- BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada
- Bioinformatics Programme, University of British Columbia, Vancouver, BC, Canada
| | - Tobi J Ming
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Jeffrey B Joy
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada
- BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada
- Bioinformatics Programme, University of British Columbia, Vancouver, BC, Canada
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25
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Piscine Orthoreovirus (PRV)-3, but Not PRV-2, Cross-Protects against PRV-1 and Heart and Skeletal Muscle Inflammation in Atlantic Salmon. Vaccines (Basel) 2021; 9:vaccines9030230. [PMID: 33800725 PMCID: PMC8001985 DOI: 10.3390/vaccines9030230] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/26/2021] [Accepted: 03/02/2021] [Indexed: 02/06/2023] Open
Abstract
Heart and skeletal muscle inflammation (HSMI), caused by infection with Piscine orthoreovirus-1 (PRV-1), is a common disease in farmed Atlantic salmon (Salmo salar). Both an inactivated whole virus vaccine and a DNA vaccine have previously been tested experimentally against HSMI and demonstrated to give partial but not full protection. To understand the mechanisms involved in protection against HSMI and evaluate the potential of live attenuated vaccine strategies, we set up a cross-protection experiment using PRV genotypes not associated with disease development in Atlantic salmon. The three known genotypes of PRV differ in their preference of salmonid host species. The main target species for PRV-1 is Atlantic salmon. Coho salmon (Oncorhynchus kisutch) is the target species for PRV-2, where the infection may induce erythrocytic inclusion body syndrome (EIBS). PRV-3 is associated with heart pathology and anemia in rainbow trout, but brown trout (S. trutta) is the likely natural main host species. Here, we tested if primary infection with PRV-2 or PRV-3 in Atlantic salmon could induce protection against secondary PRV-1 infection, in comparison with an adjuvanted, inactivated PRV-1 vaccine. Viral kinetics, production of cross-reactive antibodies, and protection against HSMI were studied. PRV-3, and to a low extent PRV-2, induced antibodies cross-reacting with the PRV-1 σ1 protein, whereas no specific antibodies were detected after vaccination with inactivated PRV-1. Ten weeks after immunization, the fish were challenged through cohabitation with PRV-1-infected shedder fish. A primary PRV-3 infection completely blocked PRV-1 infection, while PRV-2 only reduced PRV-1 infection levels and the severity of HSMI pathology in a few individuals. This study indicates that infection with non-pathogenic, replicating PRV could be a future strategy to protect farmed salmon from HSMI.
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26
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Bateman AW, Schulze AD, Kaukinen KH, Tabata A, Mordecai G, Flynn K, Bass A, Di Cicco E, Miller KM. Descriptive multi-agent epidemiology via molecular screening on Atlantic salmon farms in the northeast Pacific Ocean. Sci Rep 2021; 11:3466. [PMID: 33568681 PMCID: PMC7876018 DOI: 10.1038/s41598-020-78978-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/24/2020] [Indexed: 02/07/2023] Open
Abstract
Rapid expansion of salmon aquaculture has resulted in high-density populations that host diverse infectious agents, for which surveillance and monitoring are critical to disease management. Screening can reveal infection diversity from which disease arises, differential patterns of infection in live and dead fish that are difficult to collect in wild populations, and potential risks associated with agent transmission between wild and farmed hosts. We report results from a multi-year infectious-agent screening program of farmed salmon in British Columbia, Canada, using quantitative PCR to assess presence and load of 58 infective agents (viruses, bacteria, and eukaryotes) in 2931 Atlantic salmon (Salmo salar). Our analysis reveals temporal trends, agent correlations within hosts, and agent-associated mortality signatures. Multiple agents, most notably Tenacibaculum maritimum, were elevated in dead and dying salmon. We also report detections of agents only recently shown to infect farmed salmon in BC (Atlantic salmon calicivirus, Cutthroat trout virus-2), detection in freshwater hatcheries of two marine agents (Kudoa thyrsites and Tenacibaculum maritimum), and detection in the ocean of a freshwater agent (Flavobacterium psychrophilum). Our results provide information for farm managers, regulators, and conservationists, and enable further work to explore patterns of multi-agent infection and farm/wild transmission risk.
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Affiliation(s)
- Andrew W Bateman
- Pacific Salmon Foundation, Vancouver, Canada. .,Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.
| | - Angela D Schulze
- Molecular Genetics, Fisheries and Oceans Canada, Nanaimo, Canada
| | - Karia H Kaukinen
- Molecular Genetics, Fisheries and Oceans Canada, Nanaimo, Canada
| | - Amy Tabata
- Molecular Genetics, Fisheries and Oceans Canada, Nanaimo, Canada
| | - Gideon Mordecai
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Kelsey Flynn
- Molecular Genetics, Fisheries and Oceans Canada, Nanaimo, Canada
| | - Arthur Bass
- Pacific Salmon Foundation, Vancouver, Canada.,Forest and Conservation Sciences, University of British Columbia, Vancouver, Canada
| | | | - Kristina M Miller
- Molecular Genetics, Fisheries and Oceans Canada, Nanaimo, Canada.,Forest and Conservation Sciences, University of British Columbia, Vancouver, Canada
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27
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Extensive Phylogenetic Analysis of Piscine Orthoreovirus Genomic Sequences Shows the Robustness of Subgenotype Classification. Pathogens 2021; 10:pathogens10010041. [PMID: 33430212 PMCID: PMC7825714 DOI: 10.3390/pathogens10010041] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 01/04/2021] [Accepted: 01/05/2021] [Indexed: 11/17/2022] Open
Abstract
Piscine orthoreovirus (PRV) belongs to the family Reoviridae and has been described mainly in association with salmonid infections. The genome of PRV consists of about 23,600 bp, with 10 segments of double-stranded RNA, classified as small (S1 to S4), medium (M1, M2 and M3) and large (L1, L2 and L3); these range approximately from 1000 bp (segment S4) to 4000 bp (segment L1). How the genetic variation among PRV strains affects the virulence for salmonids is still poorly understood. The aim of this study was to describe the molecular phylogeny of PRV based on an extensive sequence analysis of the S1 and M2 segments of PRV available in the GenBank database to date (May 2020). The analysis was extended to include new PRV sequences for S1 and M2 segments. In addition, subgenotype classifications were assigned to previously published unclassified sequences. It was concluded that the phylogenetic trees are consistent with the original classification using the PRV genomic segment S1, which differentiates PRV into two major genotypes, I and II, and each of these into two subgenotypes, designated as Ia and Ib, and IIa and IIb, respectively. Moreover, some clusters of country- and host-specific PRV subgenotypes were observed in the subset of sequences used. This work strengthens the subgenotype classification of PRV based on the S1 segment and can be used to enhance research on the virulence of PRV.
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28
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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] [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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29
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Piscine Orthoreovirus-1 Isolates Differ in Their Ability to Induce Heart and Skeletal Muscle Inflammation in Atlantic Salmon ( Salmo salar). Pathogens 2020; 9:pathogens9121050. [PMID: 33327651 PMCID: PMC7765100 DOI: 10.3390/pathogens9121050] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 12/13/2022] Open
Abstract
Piscine orthoreovirus 1 (PRV-1) is the causative agent of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar). The virus is widespread in Atlantic salmon and was present in Norway long before the first description of HSMI in 1999. Furthermore, in Canada the virus is prevalent in farmed Atlantic salmon but HSMI is not and Canadian isolates have failed to reproduce HSMI experimentally. This has led to the hypothesis that there are virulence differences between PRV-1 isolates. In this study we performed a dose standardized challenge trial, comparing six PRV-1 isolates, including two Norwegian field isolates from 2018, three historical Norwegian isolates predating the first report of HSMI and one Canadian isolate. The Norwegian 2018 isolates induced lower viral protein load in blood cells but higher plasma viremia. Following peak replication in blood, the two Norwegian 2018 isolates induced histopathological lesions in the heart consistent with HSMI, whereas all three historical Norwegian and the Canadian isolates induced only mild cardiac lesions. This is the first demonstration of virulence differences between PRV-1 isolates and the phenotypic differences are linked to viral proteins encoded by segment S1, M2, L1, L2 and S4.
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30
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Polinski MP, Vendramin N, Cuenca A, Garver KA. Piscine orthoreovirus: Biology and distribution in farmed and wild fish. JOURNAL OF FISH DISEASES 2020; 43:1331-1352. [PMID: 32935367 DOI: 10.1111/jfd.13228] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/06/2020] [Accepted: 07/08/2020] [Indexed: 06/11/2023]
Abstract
Piscine orthoreovirus (PRV) is a common and widely distributed virus of salmonids. Since its discovery in 2010, the virus has been detected in wild and farmed stocks from North America, South America, Europe and East Asia in both fresh and salt water environments. Phylogenetic analysis suggests three distinct genogroups of PRV with generally discrete host tropisms and/or regional patterns. PRV-1 is found mainly in Atlantic (Salmo salar), Chinook (Oncorhynchus tshawytscha) and Coho (Oncorhynchus kisutch) Salmon of Europe and the Americas; PRV-2 has only been detected in Coho Salmon of Japan; and PRV-3 has been reported primarily in Rainbow Trout (Oncorhynchus mykiss) in Europe. All three genotypes can establish high-load systemic infections by targeting red blood cells for principal replication. Each genotype has also demonstrated potential to cause circulatory disease. At the same time, high-load PRV infections occur in non-diseased salmon and trout, indicating a complexity for defining PRV's role in disease aetiology. Here, we summarize the current body of knowledge regarding PRV following 10 years of study.
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Affiliation(s)
- Mark P Polinski
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - 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
| | - Kyle A Garver
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
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31
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Pham PH, Misk E, Papazotos F, Jones G, Polinski MP, Contador E, Russell S, Garver KA, Lumsden JS, Bols NC. Screening of Fish Cell Lines for Piscine Orthoreovirus-1 (PRV-1) Amplification: Identification of the Non-Supportive PRV-1 Invitrome. Pathogens 2020; 9:E833. [PMID: 33053677 PMCID: PMC7601784 DOI: 10.3390/pathogens9100833] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/05/2020] [Accepted: 10/09/2020] [Indexed: 12/16/2022] Open
Abstract
Piscine reovirus (PRV) is the causative agent of heart and skeletal muscle inflammation (HSMI), which is detrimental to Atlantic Salmon (AS) aquaculture, but so far has not been cultivatable, which impedes studying the disease and developing a vaccine. Homogenates of head kidney and red blood cells (RBC) from AS in which PRV-1 had been detected were applied to fish cell lines. The cell lines were from embryos, and from brain, blood, fin, gill, gonads, gut, heart, kidney, liver, skin, and spleen, and had the shapes of endothelial, epithelial, fibroblast, and macrophage cells. Most cell lines were derived from the Neopterygii subclass of fish, but one was from subclass Chondrostei. Cultures were examined by phase contrast microscopy for appearance, and by quantitative polymerase chain reaction (qPCR) for PRV-1 RNA amplification and for the capacity to transfer any changes to new cultures. No changes in appearance and Ct values were observed consistently or transferable to new cultures. Therefore, 31 cell lines examined were unable to support PRV-1 amplification and are described as belonging to the non-supportive PRV-1 invitrome. However, these investigations and cell lines can contribute to understanding PRV-1 cellular and host tropism, and the interactions between virus-infected and bystander cells.
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Affiliation(s)
- Phuc H. Pham
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (F.P.); (N.C.B.)
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada; (E.C.); (J.S.L.)
| | - Ehab Misk
- Huntsman Marine Science Centre, St. Andrews, NB E5B 2L7, Canada;
| | - Fotini Papazotos
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (F.P.); (N.C.B.)
| | - Ginny Jones
- Elanco Canada Limited, Aqua Vaccines R&D, Charlottetown, PE C1E 2A7, Canada;
| | - Mark P. Polinski
- Pacific Biological Station, Department of Fisheries and Oceans, Nanaimo, BC V9T 6N7, Canada; (M.P.P.); (K.A.G.)
| | - Elena Contador
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada; (E.C.); (J.S.L.)
| | - Spencer Russell
- Fisheries and Aquaculture, Vancouver Island University, Nanaimo, BC V9R 5S5, Canada;
| | - Kyle A. Garver
- Pacific Biological Station, Department of Fisheries and Oceans, Nanaimo, BC V9T 6N7, Canada; (M.P.P.); (K.A.G.)
| | - John S. Lumsden
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada; (E.C.); (J.S.L.)
| | - Niels C. Bols
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (F.P.); (N.C.B.)
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Emergence and Spread of Piscine orthoreovirus Genotype 3. Pathogens 2020; 9:pathogens9100823. [PMID: 33036449 PMCID: PMC7601675 DOI: 10.3390/pathogens9100823] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/29/2020] [Accepted: 10/02/2020] [Indexed: 02/07/2023] Open
Abstract
Piscine orthoreovirus (PRV) is a relevant pathogen for salmonid aquaculture worldwide. In 2015, a new genotype of PRV (genotype 3, PRV-3) was discovered in Norway, and in 2017 PRV-3 was detected for first time in Denmark in association with complex disease cases in rainbow trout in recirculating aquaculture systems (RAS). To explore the epidemiology of PRV-3 in Denmark, a surveillance study was conducted in 2017 to 2019. Fifty-three farms, including both flow through and RAS, were screened for PRV-3. Of the farms examined, PRV-3 was detected in thirty-eight (71.7%), with the highest prevalence in grow-out farms. Notably, in Denmark disease outbreaks were only observed in RAS. Additionally, wild Atlantic salmon and brown trout populations were included in the screening, and PRV-3 was not detected in the three years where samples were obtained (2016, 2018, and 2019). Historical samples in the form of archived material at the Danish National Reference Laboratory for Fish Diseases were also tested for the presence of PRV-3, allowing us to establish that the virus has been present in Denmark at least since 1995. Sequence analyses of segment S1 and M2, as well as full genome analyses of selected isolates, did not reveal clear association between genetic makeup in these two segments and virulence in the form of disease outbreaks in the field.
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Marty GD, Bidulka J, Joseph T. Cross-sectional study of histopathology and piscine orthoreovirus during a marine production cycle of farmed Atlantic salmon (Salmo salar L.) in British Columbia, Canada. JOURNAL OF FISH DISEASES 2020; 43:1019-1028. [PMID: 33448429 DOI: 10.1111/jfd.13210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/30/2020] [Accepted: 06/01/2020] [Indexed: 06/12/2023]
Abstract
Two cohorts of farmed Atlantic salmon, Salmo salar L., in British Columbia, Canada, were sampled for histopathology (nine organs) and piscine orthoreovirus (PRV-1) PCR after seawater entry at 2, 4, 6, 8, 10, 13, 16 and 19 months (20 fish per cohort per date). One cohort-from a PRV+ hatchery-remained PRV+ throughout the study (sample prevalence 80%-100%). In an adjacent pen, the other cohort-from a PRV- hatchery-was 0% PRV+ at 78 days, 30% PRV+ at 128 days and ≥95% PRV+ thereafter. Among sample cohorts that were ≥80% PRV+, median Ct values were nominally less among fish sourced from the PRV- hatchery (28.7-33.3) than the PRV+ hatchery (30.8-35.2). No microscopic lesions were associated with PRV Ct value (minimum = 25.6). About 3% of fish in both cohorts had moderate inflammatory heart lesions; among these fish, only one had skeletal muscle inflammation (mild), and PRV Ct values were similar to unaffected cohorts sampled the same day. Also, among 16 moribund or freshly dead fish sampled opportunistically during the study, 14 were PRV+, and none had significant inflammatory heart lesions. These data support the hypothesis that British Columbia PRV-1 does not contribute to mortality.
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Affiliation(s)
- Gary D Marty
- Animal Health Centre, Ministry of Agriculture, Abbotsford, BC, Canada
| | - Julie Bidulka
- Animal Health Centre, Ministry of Agriculture, Abbotsford, BC, Canada
| | - Tomy Joseph
- Animal Health Centre, Ministry of Agriculture, Abbotsford, BC, Canada
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Wessel Ø, Hansen EF, Løvoll M, Inami M, Husby A, Kruse G, Dahle MK, Rimstad E. Inactivation of Piscine orthoreovirus. JOURNAL OF FISH DISEASES 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] [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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Siah A, Knutsen E, Richmond Z, Mills M, Frisch K, Powell JFF, Brevik Ø, Duesund H. Real-time RT-qPCR assay to detect sequences in the Piscine orthoreovirus-1 genome segment S1 associated with heart and skeletal muscle inflammation in Atlantic salmon. JOURNAL OF FISH DISEASES 2020; 43:955-962. [PMID: 32608050 DOI: 10.1111/jfd.13205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 06/11/2023]
Abstract
During the last decade, Piscine orthoreovirus was identified as the main causative agent of heart and skeletal muscle inflammation (HSMI) in Atlantic Salmon, Norway. A recent study showed that PRV-1 sequences from salmonid collected in North Atlantic Pacific Coast (NAPC) grouped separately from the Norwegian sequences found in Atlantic Salmon diagnosed with HSMI. Currently, the routine assay used to screen for PRV-1 in NAPC water and worldwide cannot differentiate between the two groups of PRV-1. Therefore, this study aimed at developing a real-time polymerase chain reaction (RT-qPCR) assay to target the PRV-1 genome segments specific for variants associated with HSMI. The assay was optimized and tested against 71 tissue samples collected from different regions including Norway, Chile and both coast of Canada and different hosts farmed Atlantic Salmon, wild Coho Salmon and escaped Atlantic Salmon collected in British Columbia, West Coast of Canada. This assay has the potential to be used for screening salmonids and non-salmonids that may carry PRV-1 potentially causing HSMI.
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Affiliation(s)
- Ahmed Siah
- British Columbia Centre for Aquatic Health Sciences, Campbell River, BC, Canada
| | | | - Zina Richmond
- British Columbia Centre for Aquatic Health Sciences, Campbell River, BC, Canada
| | | | | | - James F F Powell
- British Columbia Centre for Aquatic Health Sciences, Campbell River, BC, Canada
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Siah A, Breyta RB, Warheit KI, Gagne N, Purcell MK, Morrison D, Powell JFF, Johnson SC. Genomes reveal genetic diversity of Piscine orthoreovirus in farmed and free-ranging salmonids from Canada and USA. Virus Evol 2020; 6:veaa054. [PMID: 33381304 PMCID: PMC7751156 DOI: 10.1093/ve/veaa054] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Piscine orthoreovirus (PRV-1) is a segmented RNA virus, which is commonly found in salmonids in the Atlantic and Pacific Oceans. PRV-1 causes the heart and skeletal muscle inflammation disease in Atlantic salmon and is associated with several other disease conditions. Previous phylogenetic studies of genome segment 1 (S1) identified four main genogroups of PRV-1 (S1 genogroups I–IV). The goal of the present study was to use Bayesian phylogenetic inference to expand our understanding of the spatial, temporal, and host patterns of PRV-1 from the waters of the northeast Pacific. To that end, we determined the coding genome sequences of fourteen PRV-1 samples that were selected to improve our knowledge of genetic diversity across a broader temporal, geographic, and host range, including the first reported genome sequences from the northwest Atlantic (Eastern Canada). Nucleotide and amino acid sequences of the concatenated genomes and their individual segments revealed that established sequences from the northeast Pacific were monophyletic in all analyses. Bayesian inference phylogenetic trees of S1 sequences using BEAST and MrBayes also found that sequences from the northeast Pacific grouped separately from sequences from other areas. One PRV-1 sample (WCAN_BC17_AS_2017) from an escaped Atlantic salmon, collected in British Columbia but derived from Icelandic broodstock, grouped with other S1 sequences from Iceland. Our concatenated genome and S1 analysis demonstrated that PRV-1 from the northeast Pacific is genetically distinct but descended from PRV-1 from the North Atlantic. However, the analyses were inconclusive as to the timing and exact source of introduction into the northeast Pacific, either from eastern North America or from European waters of the North Atlantic. There was no evidence that PRV-1 was evolving differently between free-ranging Pacific Salmon and farmed Atlantic Salmon. The northeast Pacific PRV-1 sequences fall within genogroup II based on the classification of Garseth, Ekrem, and Biering (Garseth, A. H., Ekrem, T., and Biering, E. (2013) ‘Phylogenetic Evidence of Long Distance Dispersal and Transmission of Piscine Reovirus (PRV) between Farmed and Wild Atlantic Salmon’, PLoS One, 8: e82202.), which also includes North Atlantic sequences from Eastern Canada, Iceland, and Norway. The additional full-genome sequences herein strengthen our understanding of phylogeographical patterns related to the northeast Pacific, but a more balanced representation of full PRV-1 genomes from across its range, as well additional sequencing of archived samples, is still needed to better understand global relationships including potential transmission links among regions.
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Affiliation(s)
- A Siah
- British Columbia Centre for Aquatic Health Sciences, 871A Island Highway, V9W 2C2, Campbell River, BC, Canada
| | - R B Breyta
- School of Aquatic Fisheries Sciences, University of Washington, Western Fisheries Research Center, USGS, 6505 NE 65th Street Seattle, WA 98115-5016, USA
| | - K I Warheit
- Washington Department of Fish and Wildlife PO Box 43200, Olympia, WA 98504-3200, USA
| | - N Gagne
- Gulf Fisheries Center, Fisheries & Oceans, 343 Université Ave, Moncton, NB E1C 5K4, Canada
| | - M K Purcell
- Western Fisheries Research Center, U.S. Geological Survey, 56505 NE 65th Street Seattle, WA 98115-5016, USA
| | - D Morrison
- Mowi Canada West, Campbell River, BC, Canada
| | - J F F Powell
- British Columbia Centre for Aquatic Health Sciences, 871A Island Highway, V9W 2C2, Campbell River, BC, Canada
| | - S C Johnson
- Fisheries & Oceans Canada, Nanaimo, British Columbia, Canada
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Purcell MK, Powers RL, Taksdal T, McKenney D, Conway CM, Elliott DG, Polinski M, Garver K, Winton J. Consequences of Piscine orthoreovirus genotype 1 (PRV-1) infections in Chinook salmon (Oncorhynchus tshawytscha), coho salmon (O. kisutch) and rainbow trout (O. mykiss). JOURNAL OF FISH DISEASES 2020; 43:719-728. [PMID: 32476167 PMCID: PMC7384080 DOI: 10.1111/jfd.13182] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 02/03/2020] [Accepted: 02/05/2020] [Indexed: 05/02/2023]
Abstract
Piscine orthoreovirus genotype 1 (PRV-1) is the causative agent of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar L.). The virus has also been found in Pacific salmonids in western North America, raising concerns about the risk to native salmon and trout. Here, we report the results of laboratory challenges using juvenile Chinook salmon, coho salmon and rainbow trout injected with tissue homogenates from Atlantic salmon testing positive for PRV-1 or with control material. Fish were sampled at intervals to assess viral RNA transcript levels, haematocrit, erythrocytic inclusions and histopathology. While PRV-1 replicated in all species, there was negligible mortality in any group. We observed a few erythrocytic inclusion bodies in fish from the PRV-1-infected groups. At a few time points, haematocrits were significantly lower in the PRV-1-infected groups relative to controls, but in no case was anaemia noted. The most common histopathological finding was mild, focal myocarditis in both the non-infected controls and PRV-1-infected fish. All cardiac lesions were judged mild, and none were consistent with those of HSMI. Together, these results suggest all three species are susceptible to PRV-1 infection, but in no case did infection cause notable disease in these experiments.
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Affiliation(s)
| | - Rachel L. Powers
- U.S. Geological SurveyWestern Fisheries Research CenterSeattleWAUSA
| | | | - Doug McKenney
- School of Aquatic and Fishery SciencesUniversity of WashingtonSeattleWAUSA
| | - Carla M. Conway
- U.S. Geological SurveyWestern Fisheries Research CenterSeattleWAUSA
| | - Diane G. Elliott
- U.S. Geological SurveyWestern Fisheries Research CenterSeattleWAUSA
| | - Mark Polinski
- Pacific Biological Station, Fisheries and Oceans CanadaNanaimoBCCanada
| | - Kyle Garver
- Pacific Biological Station, Fisheries and Oceans CanadaNanaimoBCCanada
| | - James Winton
- U.S. Geological SurveyWestern Fisheries Research CenterSeattleWAUSA
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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] [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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Flores-Kossack C, Montero R, Köllner B, Maisey K. Chilean aquaculture and the new challenges: Pathogens, immune response, vaccination and fish diversification. FISH & SHELLFISH IMMUNOLOGY 2020; 98:52-67. [PMID: 31899356 DOI: 10.1016/j.fsi.2019.12.093] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 11/29/2019] [Accepted: 12/30/2019] [Indexed: 06/10/2023]
Abstract
In Chile, the salmon and trout farmed fishing industries have rapidly grown during the last years, becoming one of the most important economic sources for the country. However, infectious diseases caused by bacteria, virus, mycoses and parasites, result in losses of up to 700 million dollars per year for the Chilean aquaculture production with the consequent increase of antibiotic and antiparasitic usage. After 30 years of its first appearance, the main salmon health problem is still the salmonid rickettsial septicaemia (SRS), which together with other disease outbreaks, reveal that vaccines do not provide acceptable levels of long-lasting immune protection in the field. On the other hand, due to the large dependence of the industry on salmonids production, the Chilean government promoted the Aquaculture diversification program by 2009, which includes new species such as Merluccius australis, Cilus gilberti and Genypterus chilensis, however, specific research regarding the immune system and vaccine development are issues that still need to be addressed and must be considered as important as the farm production technologies for new fish species. Based on the experience acquired from the salmonid fish farming, should be mandatory an effort to study the immune system of the new species to develop knowledge for vaccination approaches, aiming to protect these aquaculture species before diseases outbreaks may occur. This review focuses on the current status of the Chilean aquaculture industry, the challenges related to emerging and re-emerging microbial pathogens on salmonid fish farming, and the resulting needs in the development of immune protection by rational designed vaccines. We also discussed about what we have learn from 25 years of salmonid researches and what can be applied to the new Chilean farmed species on immunology and vaccinology.
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Affiliation(s)
- C Flores-Kossack
- Laboratorio de Inmunología Comparativa, Centro de Biotecnología Acuícola (CBA), Universidad de Santiago de Chile, Alameda, 3363, Santiago, Chile
| | - R Montero
- Institute of Immunology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - B Köllner
- Institute of Immunology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - K Maisey
- Laboratorio de Inmunología Comparativa, Centro de Biotecnología Acuícola (CBA), Universidad de Santiago de Chile, Alameda, 3363, Santiago, Chile.
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Dissemination of Piscine orthoreovirus-1 (PRV-1) in Atlantic Salmon ( Salmo salar) during the Early and Regenerating Phases of Infection. Pathogens 2020; 9:pathogens9020143. [PMID: 32093243 PMCID: PMC7169402 DOI: 10.3390/pathogens9020143] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/14/2020] [Accepted: 02/17/2020] [Indexed: 12/12/2022] Open
Abstract
Piscine orthoreovirus-1 (PRV-1) can cause heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar), but the line of events from infection, pathologic change, and regeneration has not been thoroughly described. In this study, the cellular localization and variation of PRV-1 RNA and protein levels were analyzed at different times post-exposure in experimentally infected Atlantic salmon. Immunohistochemistry, flow cytometry, and Western blot were used for assessment of the presence of the PRV-1 σ1 protein, while RT-qPCR and in situ hybridization were performed for viral RNA. Histopathologic evaluation demonstrated that PRV-1 infection induced heart lesions typical of HSMI, such as severe epicarditis and myocarditis with degeneration of cardiomyocytes, necrosis, and diffuse cellular infiltration. PRV-1 infection of erythrocytes and the peak viral plasma level preceded virus presence in cardiomyocytes and hepatocytes. Arginase-2-positive, macrophage-like cells observed in the heart indicated possible polarization to M2 macrophages and the onset of regenerative processes, which may contribute to the recovery from HSMI. The virus was cleared from regenerating heart tissue and from hepatocytes, but persisted in erythrocytes.
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41
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Teffer AK, Carr J, Tabata A, Schulze A, Bradbury I, Deschamps D, Gillis CA, Brunsdon EB, Mordecai G, Miller KM. A molecular assessment of infectious agents carried by Atlantic salmon at sea and in three eastern Canadian rivers, including aquaculture escapees and North American and European origin wild stocks. Facets (Ott) 2020. [DOI: 10.1139/facets-2019-0048] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Infectious agents are key components of animal ecology and drivers of host population dynamics. Knowledge of their diversity and transmission in the wild is necessary for the management and conservation of host species like Atlantic salmon ( Salmo salar). Although pathogen exchange can occur throughout the salmon life cycle, evidence is lacking to support transmission during population mixing at sea or between farmed and wild salmon due to aquaculture exposure. We tested these hypotheses using a molecular approach that identified infectious agents and transmission potential among sub-adult Atlantic salmon at marine feeding areas and adults in three eastern Canadian rivers with varying aquaculture influence. We used high-throughput qPCR to quantify infection profiles and next generation sequencing to measure genomic variation among viral isolates. We identified 14 agents, including five not yet described as occurring in Eastern Canada. Phylogenetic analysis of piscine orthoreovirus showed homology between isolates from European and North American origin fish at sea, supporting the hypothesis of intercontinental transmission. We found no evidence to support aquaculture influence on wild adult infections, which varied relative to environmental conditions, life stage, and host origin. Our findings identify research opportunities regarding pathogen transmission and biological significance for wild Atlantic salmon populations.
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Affiliation(s)
- Amy K. Teffer
- Department of Forest and Conservation Sciences, University of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada
| | - Jonathan Carr
- Atlantic Salmon Federation, Chamcook, NB E5B 3A9, Canada
| | - Amy Tabata
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7, Canada
| | - Angela Schulze
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7, Canada
| | - Ian Bradbury
- Salmonids Section, Fisheries and Oceans Canada, St. John’s, NF A1C 5X1, Canada
| | - Denise Deschamps
- Ministère des Forêts, de la Faune et des Parcs du Québec, Direction de l’expertise sur la faune aquatique, Quebec, QC G1S 4X4, Canada
| | | | | | - Gideon Mordecai
- Department of Medicine, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
| | - Kristina M. Miller
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7, Canada
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Matsuura Y, Terashima S, Takano T, Matsuyama T. Current status of fish vaccines in Japan. FISH & SHELLFISH IMMUNOLOGY 2019; 95:236-247. [PMID: 31586679 DOI: 10.1016/j.fsi.2019.09.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 09/13/2019] [Accepted: 09/14/2019] [Indexed: 06/10/2023]
Abstract
Aquaculture is an important industry in Japan for the sustainable production of fish. It contributes to the diversity of Japanese traditional food culture, which uses fish such as "sushi" and "sashimi". In the recent aquaculture setting in Japan, infectious diseases have been an unavoidable problem and have caused serious economic losses. Therefore, there is an urgent need to overcome the disease problem to increase the productivity of aquaculture. Although our country has developed various effective vaccines against fish pathogens, which have contributed to disease prevention on fish farms, infectious diseases that cannot be controlled by conventional inactivated vaccines are still a problem. Therefore, other approaches to developing effective vaccines other than inactivated vaccines are required. This review introduces the vaccine used in Japan within the context of the current status of finfish aquacultural production and disease problems. This review also summarizes the current research into vaccine development and discusses the future perspectives of fish vaccines, focusing on the problems associated with vaccine promotion in Japan.
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Affiliation(s)
- Yuta Matsuura
- Research Center of Fish Diseases, National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami.-Ise, Mie, Japan
| | - Sachiko Terashima
- Research Center of Fish Diseases, National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami.-Ise, Mie, Japan
| | - Tomokazu Takano
- Research Center of Fish Diseases, National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami.-Ise, Mie, Japan
| | - Tomomasa Matsuyama
- Research Center of Fish Diseases, National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami.-Ise, Mie, Japan.
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43
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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: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [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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44
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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] [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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45
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Nekouei O, Vanderstichel R, Kaukinen KH, Thakur K, Ming T, Patterson DA, Trudel M, Neville C, Miller KM. Comparison of infectious agents detected from hatchery and wild juvenile Coho salmon in British Columbia, 2008-2018. PLoS One 2019; 14:e0221956. [PMID: 31479469 PMCID: PMC6719873 DOI: 10.1371/journal.pone.0221956] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 08/19/2019] [Indexed: 02/03/2023] Open
Abstract
Infectious diseases are potential contributors to decline in Coho salmon (Oncorhynchus kisutch) populations. Although pathogens are theoretically considered to pose higher risk in high-density rearing environments like hatcheries, there is no direct evidence that hatchery-origin Coho salmon increase the transmission of infectious agents to sympatric wild populations. This study was undertaken to compare prevalence, burden, and diversity of infectious agents between hatchery-reared and wild juvenile Coho salmon in British Columbia (BC), Canada. In total, 2,655 juvenile Coho salmon were collected between 2008 and 2018 from four regions of freshwater and saltwater in BC. High-throughput microfluidics qPCR was employed for simultaneous detection of 36 infectious agents from mixed-tissue samples (gill, brain, heart, liver, and kidney). Thirty-one agents were detected at least once, including ten with prevalence >5%. Candidatus Brachiomonas cysticola, Paraneuclospora theridion, and Parvicapsula pseudobranchiocola were the most prevalent agents. Diversity and burden of infectious agents were substantially higher in marine environment than in freshwater. In Mainland BC, infectious burden and diversity were significantly lower in hatchery smolts than in wild counterparts, whereas in other regions, there were no significant differences. Observed differences in freshwater were predominantly driven by three parasites, Loma salmonae, Myxobolus arcticus, and Parvicapsula kabatai. In saltwater, there were no consistent differences in agent prevalence between hatchery and wild fish shared among the west and east coasts of Vancouver Island. Although some agents showed differential infectious patterns between regions, annual variations likely contributed to this signal. Our findings do not support the hypothesis that hatchery smolts carry higher burdens of infectious agents than conspecific wild fish, reducing the potential risk of transfer to wild smolts at this life stage. Moreover, we provide a baseline of infectious agents in juvenile Coho salmon that will be used in future research and modeling potential correlations between infectious profiles and marine survival.
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Affiliation(s)
- Omid Nekouei
- Department of Health Management, University of Prince Edward Island, Charlottetown, PE, Canada
- * E-mail:
| | - Raphael Vanderstichel
- Department of Health Management, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Karia H. Kaukinen
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Krishna Thakur
- Department of Health Management, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Tobi Ming
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - David A. Patterson
- Fisheries and Oceans Canada, Cooperative Resource Management Institute, School of Resources and Environment Management, Simon Fraser University, Burnaby, BC, Canada
| | - Marc Trudel
- St. Andrews Biological Station, Fisheries and Oceans Canada, St. Andrews, NB, Canada
| | - Chrys Neville
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Kristina M. Miller
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
- Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada
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46
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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. JOURNAL OF FISH DISEASES 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] [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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47
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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). JOURNAL OF FISH DISEASES 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] [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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48
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Evolution of the Piscine orthoreovirus Genome Linked to Emergence of Heart and Skeletal Muscle Inflammation in Farmed Atlantic Salmon ( Salmo salar). Viruses 2019; 11:v11050465. [PMID: 31121920 PMCID: PMC6563308 DOI: 10.3390/v11050465] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/16/2019] [Accepted: 05/20/2019] [Indexed: 01/09/2023] Open
Abstract
Heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar) was first diagnosed in Norway in 1999. The disease is caused by Piscine orthoreovirus-1 (PRV-1). The virus is prevalent in farmed Atlantic salmon, but not always associated with disease. Phylogeny and sequence analyses of 31 PRV-1 genomes collected over a 30-year period from fish with or without HSMI, grouped the viral sequences into two main monophylogenetic clusters, one associated with HSMI and the other with low virulent PRV-1 isolates. A PRV-1 strain from Norway sampled in 1988, a decade before the emergence of HSMI, grouped with the low virulent HSMI cluster. The two distinct monophylogenetic clusters were particularly evident for segments S1 and M2. Only a limited number of amino acids were unique to the association with HSMI, and they all located to S1 and M2 encoded proteins. The observed co-evolution of the S1-M2 pair coincided in time with the emergence of HSMI in Norway, and may have evolved through accumulation of mutations and/or segment reassortment. Sequences of S1-M2 suggest selection of the HSMI associated pair, and that this segment pair has remained almost unchanged in Norwegian salmon aquaculture since 1997. PRV-1 strains from the North American Pacific Coast and Faroe Islands have not undergone this evolution, and are more closely related to the PRV-1 precursor strains not associated with clinical HSMI.
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49
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Kibenge MJT, Wang Y, Gayeski N, Morton A, Beardslee K, McMillan B, Kibenge FSB. Piscine orthoreovirus sequences in escaped farmed Atlantic salmon in Washington and British Columbia. Virol J 2019; 16:41. [PMID: 30940162 PMCID: PMC6444584 DOI: 10.1186/s12985-019-1148-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 03/19/2019] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Piscine orthoreovirus (PRV) is an emergent virus in salmon aquaculture belonging to the family Reoviridae. PRV is associated with a growing list of pathological conditions including heart and skeletal inflammation (HSMI) of farmed Atlantic salmon. Despite widespread PRV infection in commercially farmed Atlantic salmon, information on PRV prevalence and on the genetic sequence variation of PRV in Atlantic salmon on the north Pacific Coast is limited. METHODS Feral Atlantic salmon caught in Washington State and British Columbia following a large containment failure at a farm in northern Puget Sound were sampled. Fish tissues were tested for PRV by RT-qPCR assay for segment L1 and conventional RT-PCR for PRV segment S1. The PCR products were sequenced and their relationship to PRV strains in GenBank was determined using phylogenetic analysis and nucleotide and amino acid homology comparisons. RESULTS Following the escape of 253,000 Atlantic salmon from a salmon farm in Washington State, USA, 72/73 tissue samples from 27 Atlantic salmon captured shortly after the escape tested PRV-positive. We estimate PRV-prevalence in the source farm population at 95% or greater. The PRV found in the fish was identified as PRV sub-genotype Ia and very similar to PRV from farmed Atlantic salmon in Iceland. This correlates with the source of the fish in the farm. Eggs of infected fish were positive for PRV indicating the possibility of vertical transfer and spread with fish egg transports. CONCLUSIONS PRV prevalence was close to 100% in farmed Atlantic salmon that were caught in Washington State and British Columbia following a large containment failure at a farm in northern Puget Sound. The PRV strains present in the escaped Atlantic salmon were very similar to the PRV strain reported in farmed Atlantic salmon from the source hatchery in Iceland that was used to stock commercial aquaculture sites in Washington State. This study emphasizes the need to screen Atlantic salmon broodstock for PRV, particularly where used to supply eggs to the global Atlantic salmon farming industry thereby improving our understanding of PRV epidemiology.
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Affiliation(s)
- Molly J. T. Kibenge
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown, P.E.I C1A 4P3 Canada
| | - Yingwei Wang
- School of Mathematical and Computational Sciences, University of Prince Edward Island, 550 University Ave, Charlottetown, P.E.I C1A 4P3 Canada
| | - Nick Gayeski
- Wild Fish Conservancy, PO Box 402, 15629 Main St. NE, Duvall, WA 98019 USA
| | - Alexandra Morton
- Raincoast Research Society, Box 399, Sointula, BC V0N 3E0 Canada
| | - Kurt Beardslee
- Wild Fish Conservancy, PO Box 402, 15629 Main St. NE, Duvall, WA 98019 USA
| | - Bill McMillan
- Wild Fish Conservancy, PO Box 402, 15629 Main St. NE, Duvall, WA 98019 USA
| | - Frederick S. B. Kibenge
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown, P.E.I C1A 4P3 Canada
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50
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Dahle MK, Jørgensen JB. Antiviral defense in salmonids - Mission made possible? FISH & SHELLFISH IMMUNOLOGY 2019; 87:421-437. [PMID: 30708056 DOI: 10.1016/j.fsi.2019.01.043] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 01/24/2019] [Accepted: 01/27/2019] [Indexed: 06/09/2023]
Abstract
Viral diseases represent one of the major threats for salmonid aquaculture. Survival from viral infections are highly dependent on host innate antiviral immune defense, where interferons are of crucial importance. Neutralizing antibodies and T cell effector mechanisms mediate long-term antiviral protection. Despite an immune cell repertoire comparable to higher vertebrates, farmed fish often fail to mount optimal antiviral protection. In the quest to multiply and spread, viruses utilize a variety of strategies to evade or escape the host immune system. Understanding the specific interplay between viruses and host immunity at depth is crucial for developing successful vaccination and treatment strategies in mammals. However, this knowledge base is still limited for pathogenic fish viruses. Here, we have focused on five RNA viruses with major impact on salmonid aquaculture: Salmonid alphavirus, Infectious salmon anemia virus, Infectious pancreatic necrosis virus, Piscine orthoreovirus and Piscine myocarditis virus. This review explore the protective immune responses that salmonids mount to these viruses and the existing knowledge on how the viruses counteract and/or bypass the immune response, including their IFN antagonizing effects and their mechanisms to establish persisting infections.
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Affiliation(s)
- Maria K Dahle
- Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries & Economics, University of Tromsø, The Arctic University of Norway, Norway; Department of Fish Health, Norwegian Veterinary Institute, Oslo, Norway
| | - Jorunn B Jørgensen
- Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries & Economics, University of Tromsø, The Arctic University of Norway, Norway.
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