1
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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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2
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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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3
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Solarte-Murillo L, Reyes H, Ojeda L, Cárcamo JG, Pontigo JP, Loncoman CA. Analyses and Insights into Genetic Reassortment and Natural Selection as Key Drivers of Piscine orthoreovirus Evolution. Viruses 2024; 16:556. [PMID: 38675898 PMCID: PMC11053957 DOI: 10.3390/v16040556] [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] [Received: 01/05/2024] [Revised: 03/05/2024] [Accepted: 03/08/2024] [Indexed: 04/28/2024] Open
Abstract
Piscine orthoreovirus (PRV) is a pathogen that causes heart and skeletal muscle inflammation in Salmo salar and has also been linked to circulatory disorders in other farmed salmonids, such as Oncorhynchus kisutch and Oncorhynchus mykiss. The virus has a segmented, double-stranded RNA genome, which makes it possible to undergo genetic reassortment and increase its genomic diversity through point mutations. In this study, genetic reassortment in PRV was assessed using the full genome sequences available in public databases. This study used full genome sequences that were concatenated and genome-wide reassortment events, and phylogenetic analyses were performed using the recombination/reassortment detection program version 5 (RDP5 V 5.5) software. Additionally, each segment was aligned codon by codon, and overall mean distance and selection was tested using the Molecular Evolutionary Genetics Analysis X software, version 10.2 (MEGA X version 10.2). The results showed that there were 17 significant reassortment events in 12 reassortant sequences, involving genome exchange between low and highly virulent genotypes. PRV sequences from different salmonid host species did not appear to limit the reassortment. This study found that PRV frequently undergoes reassortment events to increase the diversity of its segmented genome, leading to antigenic variation and increased virulence. This study also noted that to date, no reassortment events have been described between PRV-1 and PRV-3 genotypes. However, the number of complete genomic sequences within each genotype is uneven. This is important because PRV-3 induces cross-protection against PRV-1, making it a potential vaccine candidate.
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Affiliation(s)
- Laura Solarte-Murillo
- Laboratorio de Virología Molecular, Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile;
| | - Humberto Reyes
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile;
| | - Loreto Ojeda
- Laboratorio de Bioquímica Farmacológica, Virología y Biotecnología, Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile
- Interdisciplinary Center for Aquaculture Research, INCAR, Concepción 4030000, Chile
| | - Juan G. Cárcamo
- Laboratorio de Bioquímica Farmacológica, Virología y Biotecnología, Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile
- Interdisciplinary Center for Aquaculture Research, INCAR, Concepción 4030000, Chile
| | - Juan Pablo Pontigo
- Laboratorio Institucional, Facultad de Ciencias de la Naturaleza, Escuela de Medicina Veterinaria, Universidad San Sebastián, Puerto Montt 5400000, Chile;
| | - Carlos A. Loncoman
- Laboratorio de Virología Molecular, Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile;
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4
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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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5
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Mordecai G, Bass AL, Routledge R, Di Cicco E, Teffer A, Deeg C, Bateman AW, Miller KM. Assessing the role of Piscine orthoreovirus in disease and the associated risk for wild Pacific salmon. BMC Biol 2023; 21:114. [PMID: 37208758 DOI: 10.1186/s12915-023-01548-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 02/20/2023] [Indexed: 05/21/2023] Open
Abstract
This paper is a response to Polinski, M. P. et al. Innate antiviral defense demonstrates high energetic efficiency in a bony fish. BMC Biology 19, 138 (2021). https://doi.org/10.1186/s12915-021-01069-2.
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Affiliation(s)
- Gideon Mordecai
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC, Canada.
| | - Arthur L Bass
- Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences University of British Columbia, Vancouver, BC, Canada
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Rick Routledge
- Department of Statistics and Actuarial Science, Simon Fraser University, Burnaby, BC, Canada
| | | | - Amy Teffer
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Christoph Deeg
- Pacific Salmon Foundation, Vancouver, BC, Canada
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Andrew W Bateman
- Pacific Salmon Foundation, Vancouver, BC, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - Kristina M Miller
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada
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6
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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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7
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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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8
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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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9
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Bass AL, Bateman AW, Connors BM, Staton BA, Rondeau EB, Mordecai GJ, Teffer AK, Kaukinen KH, Li S, Tabata AM, Patterson DA, Hinch SG, Miller KM. Identification of infectious agents in early marine Chinook and Coho salmon associated with cohort survival. Facets (Ott) 2022. [DOI: 10.1139/facets-2021-0102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Recent decades have seen an increased appreciation for the role infectious diseases can play in mass mortality events across a diversity of marine taxa. At the same time many Pacific salmon populations have declined in abundance as a result of reduced marine survival. However, few studies have explicitly considered the potential role pathogens could play in these declines. Using a multi-year dataset spanning 59 pathogen taxa in Chinook and Coho salmon sampled along the British Columbia coast, we carried out an exploratory analysis to quantify evidence for associations between pathogen prevalence and cohort survival and between pathogen load and body condition. While a variety of pathogens had moderate to strong negative correlations with body condition or survival for one host species in one season, we found that Tenacibaculum maritimum and Piscine orthoreovirus had consistently negative associations with body condition in both host species and seasons and were negatively associated with survival for Chinook salmon collected in the fall and winter. Our analyses, which offer the most comprehensive examination of associations between pathogen prevalence and Pacific salmon survival to date, suggest that pathogens in Pacific salmon warrant further attention, especially those whose distribution and abundance may be influenced by anthropogenic stressors.
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Affiliation(s)
- Arthur L. Bass
- Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Andrew W. Bateman
- Pacific Salmon Foundation, Vancouver, BC V6J 4S6, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
| | - Brendan M. Connors
- Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, BC V8L 5T5, Canada
| | - Benjamin A. Staton
- Fisheries Science Department, Columbia River Inter-Tribal Fish Commission, Portland, OR 97232, USA
| | - Eric B. Rondeau
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Gideon J. Mordecai
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC V9T 6N7, Canada
| | - Amy K. Teffer
- Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, 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 M. Tabata
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - David A. Patterson
- Fisheries and Oceans Canada, School of Resource and Environmental Management, Simon Fraser University, Science Branch, Burnaby, BC V5A 1S6, Canada
| | - Scott G. Hinch
- Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Kristina M. Miller
- Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
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10
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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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11
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Matsuyama T, Kiryu I, Inada M, Takano T, Matsuura Y, Kamaishi T. Susceptibility of Four Abalone Species, Haliotis gigantea, Haliotis discus discus, Haliotis discus hannai and Haliotis diversicolor, to Abalone asfa-like Virus. Viruses 2021; 13:v13112315. [PMID: 34835121 PMCID: PMC8621809 DOI: 10.3390/v13112315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/12/2021] [Accepted: 11/16/2021] [Indexed: 11/29/2022] Open
Abstract
Abalone amyotrophia is a viral disease that causes mass mortality of juvenile Haliotis discus and H. madaka. Although the cause of this disease has yet to be identified, we had previously postulated a novel virus with partial genome sequence similarity to that of African swine fever virus is the causative agent and proposed abalone asfa-like virus (AbALV) as a provisional name. In this study, three species of juvenile abalone (H. gigantea, H. discus discus, and H. diversicolor) and four species of adult abalone (the above three species plus H. discus hannai) were experimentally infected, and their susceptibility to AbALV was investigated by recording mortality, quantitatively determining viral load by PCR, and conducting immunohistological studies. In the infection test using 7-month-old animals, H. gigantea, which was previously reported to be insusceptible to the disease, showed multiplication of the virus to the same extent as in H. discus discus, resulting in mass mortality. H. discus discus at 7 months old showed abnormal cell masses, notches in the edge of the shell and brown pigmentation inside of the shell, which are histopathological and external features of this disease, while H. gigantea did not show any of these characteristics despite suffering high mortality. Adult abalones had low mortality and viral replication in all species; however, all three species, except H. diversicolor, became carriers of the virus. In immunohistological observations, cells positive for viral antigens were detected predominantly in the gills of juvenile H. discus discus and H. gigantea, and mass mortality was observed in these species. In H. diversicolor, neither juvenile nor adult mortality from infection occurred, and the AbALV genome was not increased by experimental infection through cohabitation or injection. Our results suggest that H. gigantea, H. discus discus and H. discus hannai are susceptible to AbALV, while H. diversicolor is not. These results confirmed that AbALV is the etiological agent of abalone amyotrophia.
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Affiliation(s)
- Tomomasa Matsuyama
- Research Center for Fish Diseases, National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami-Ise 516-0193, Japan; (T.T.); (Y.M.); (T.K.)
- Correspondence:
| | - Ikunari Kiryu
- Diagnosis and Training Center for Fish Diseases, National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami-Ise 516-0193, Japan; (I.K.); (M.I.)
| | - Mari Inada
- Diagnosis and Training Center for Fish Diseases, National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami-Ise 516-0193, Japan; (I.K.); (M.I.)
| | - Tomokazu Takano
- Research Center for Fish Diseases, National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami-Ise 516-0193, Japan; (T.T.); (Y.M.); (T.K.)
| | - Yuta Matsuura
- Research Center for Fish Diseases, National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami-Ise 516-0193, Japan; (T.T.); (Y.M.); (T.K.)
| | - Takashi Kamaishi
- Research Center for Fish Diseases, National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami-Ise 516-0193, Japan; (T.T.); (Y.M.); (T.K.)
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12
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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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13
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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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14
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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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15
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Isolation and characterization of hirame aquareovirus (HAqRV): A new Aquareovirus isolated from diseased hirame Paralichthys olivaceus. Virology 2021; 559:120-130. [PMID: 33865075 DOI: 10.1016/j.virol.2021.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 03/30/2021] [Accepted: 04/02/2021] [Indexed: 11/21/2022]
Abstract
We isolated a novel Aquareovirus (hirame aquareovirus: HAqRV) from Japanese flounder Paralichthys olivaceus suffering from reovirus-like infection. In electron microscopy, the spherical virion (75 nm in diameter) was observed with multi-layered capsid structure. The viral genome consisted of 11 segments and regions encoding 7 virion structural proteins and 5 non-structural proteins were predicted. The deduced amino acid sequences of those proteins were highly similar to those of the aquareoviruses. However, the similarity of complete genome sequence between the HAqRV and other aquareoviruses was less than 60%. Phylogenetic analyses based on the deduced amino acid sequences suggested that the HAqRV is not classified into the known species of Aquareovirus. Pathogenicity of HAqRV was clearly demonstrated in accordance with Koch's postulates by experimental infection using Japanese flounder. The results suggest that the HAqRV is a new Aquareovirus species which is highly virulent for the Japanese flounder at early life stages.
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16
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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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17
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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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18
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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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19
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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: 2] [Impact Index Per Article: 0.5] [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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20
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Wessel Ø, Hansen EF, Løvoll M, Inami M, Husby A, Kruse G, Dahle MK, Rimstad E. Inactivation of Piscine orthoreovirus. 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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21
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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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22
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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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23
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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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24
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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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25
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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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26
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Teige LH, Kumar S, Johansen GM, Wessel Ø, Vendramin N, Lund M, Rimstad E, Boysen P, Dahle MK. Detection of Salmonid IgM Specific to the Piscine Orthoreovirus Outer Capsid Spike Protein Sigma 1 Using Lipid-Modified Antigens in a Bead-Based Antibody Detection Assay. Front Immunol 2019; 10:2119. [PMID: 31552049 PMCID: PMC6743345 DOI: 10.3389/fimmu.2019.02119] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [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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27
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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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28
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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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29
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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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30
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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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31
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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] [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. Electronic supplementary material The online version of this article (10.1186/s12985-019-1148-2) contains supplementary material, which is available to authorized users.
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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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32
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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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33
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Polinski MP, Marty GD, Snyman HN, Garver KA. Piscine orthoreovirus demonstrates high infectivity but low virulence in Atlantic salmon of Pacific Canada. Sci Rep 2019; 9:3297. [PMID: 30867461 PMCID: PMC6416343 DOI: 10.1038/s41598-019-40025-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 02/04/2019] [Indexed: 02/05/2023] Open
Abstract
Piscine orthoreovirus (PRV) is ubiquitous in farmed Atlantic salmon and sometimes associated with disease - most notably, Heart and Skeletal Muscle Inflammation (HSMI). However, PRV is also widespread in non-diseased fish, particularly in Pacific Canada, where few cases of severe heart inflammation have been documented. To better understand the mechanisms behind PRV-associated disease, this study investigated the infection dynamics of PRV from Pacific Canada and the potential for experimental passage of putatively associated heart inflammation in Pacific-adapted Mowi-McConnell Atlantic salmon. Regardless of the PRV source (fish with or without HSMI-like heart inflammation), infections led to high-load viremia that induced only minor focal heart inflammation without significant transcriptional induction of inflammatory cytokines. Repeated screening of PRV dsRNA/ssRNA along with histopathology and gene expression analysis of host blood and heart tissues identified three distinct phases of infection: (1) early systemic dissemination and replication without host recognition; (2) peak replication, erythrocyte inclusion body formation and load-dependent host recognition; (3) long-term, high-load viral persistence with limited replication or host recognition sometimes accompanied by minor heart inflammation. These findings contrast previous challenge trials with PRV from Norway that induced severe heart inflammation and indicate that strain and/or host specific factors are necessary to initiate PRV-associated disease.
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Affiliation(s)
- Mark P Polinski
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, V9T 6N7, Canada.
| | - Gary D Marty
- Animal Health Centre, Ministry of Agriculture, Abbotsford, V3G 2M3, Canada
| | - Heindrich N Snyman
- Animal Health Centre, Ministry of Agriculture, Abbotsford, V3G 2M3, Canada
| | - Kyle A Garver
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, V9T 6N7, Canada
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34
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Zhang Y, Polinski MP, Morrison PR, Brauner CJ, Farrell AP, Garver KA. High-Load Reovirus Infections Do Not Imply Physiological Impairment in Salmon. Front Physiol 2019; 10:114. [PMID: 30930782 PMCID: PMC6425399 DOI: 10.3389/fphys.2019.00114] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 01/30/2019] [Indexed: 12/14/2022] Open
Abstract
The recent ubiquitous detection of PRV among salmonids has sparked international concern about the cardiorespiratory performance of infected wild and farmed salmon. Piscine orthoreovirus (PRV) has been shown to create substantial viremia in salmon by targeting erythrocytes for principle replication. In some instances, infections develop into heart and skeletal muscle inflammation (HSMI) or other pathological conditions affecting the respiratory system. Critical to assessing the seriousness of PRV infections are controlled infection studies that measure physiological impairment to critical life support systems. Respiratory performance is such a system and here multiple indices were measured to test the hypothesis that a low-virulence strain of PRV from Pacific Canada compromises the cardiorespiratory capabilities of Atlantic salmon. Contrary to this hypothesis, the oxygen affinity and carrying capacity of erythrocytes were unaffected by PRV despite the presence of severe viremia, minor heart pathology and transient cellular activation of antiviral response pathways. Similarly, PRV-infected fish had neither sustained nor appreciable differences in respiratory capabilities compared with control fish. The lack of functional harm to salmon infected with PRV in this instance highlights that, in an era of unprecedented virus discovery, detection of viral infection does not necessarily imply bodily harm and that viral load is not always a suitable predictor of disease within a host organism.
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Affiliation(s)
- Yangfan Zhang
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, BC, Canada
| | - Mark P Polinski
- Aquatic Diagnostics and Genomics Division, Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Phillip R Morrison
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada
| | - Colin J Brauner
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada
| | - Anthony P Farrell
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, BC, Canada.,Department of Zoology, The University of British Columbia, Vancouver, BC, Canada
| | - Kyle A Garver
- Aquatic Diagnostics and Genomics Division, Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
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35
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Garseth ÅH, Moldal T, Gåsnes SK, Hjortaas MJ, Sollien VP, Gjevre A. Piscine orthoreovirus-3 is prevalent in wild seatrout (Salmo trutta L.) in Norway. JOURNAL OF FISH DISEASES 2019; 42:391-396. [PMID: 30659618 PMCID: PMC6850415 DOI: 10.1111/jfd.12943] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 11/20/2018] [Accepted: 11/20/2018] [Indexed: 06/09/2023]
Abstract
In 2017, a PCR-based survey for Piscine orthoreovirus-3 (PRV-3) was conducted in wild anadromous and non-anadromous salmonids in Norway. In seatrout (anadromous Salmo trutta L.), the virus was present in 16.6% of the fish and in 15 of 21 investigated rivers. Four of 221 (1.8%) Atlantic salmon (Salmo salar L.) from three of 15 rivers were also PCR-positive, with Ct-values indicating low amounts of viral RNA. All anadromous Arctic char (Salvelinus alpinus L.) were PCR-negative. Neither non-anadromous trout (brown trout) nor landlocked salmon were PRV-3 positive. Altogether, these findings suggest that in Norway PRV-3 is more prevalent in the marine environment. In contrast, PRV-3 is present in areas with intensive inland farming in continental Europe. PRV-3 genome sequences from Norwegian seatrout grouped together with sequences from rainbow trout (Oncorhynchus mykiss Walbaum) in Norway and Coho salmon (Oncorhynchus kisutch Walbaum) in Chile. At present, the origin of the virus remains unknown. Nevertheless, the study highlights the value of safeguarding native fish by upholding natural and artificial barriers that hinder introduction and spread, on a local or national scale, of alien fish species and their pathogens. Accordingly, further investigations of freshwater reservoirs and interactions with farmed salmonids are warranted.
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Affiliation(s)
| | | | | | | | | | - Anne‐Gerd Gjevre
- Norwegian Veterinary InstituteOsloNorway
- Norwegian Food Safety AuthorityOsloNorway
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36
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Vendramin N, Kannimuthu D, Olsen AB, Cuenca A, Teige LH, Wessel Ø, Iburg TM, Dahle MK, Rimstad E, Olesen NJ. Piscine orthoreovirus subtype 3 (PRV-3) causes heart inflammation in rainbow trout (Oncorhynchus mykiss). Vet Res 2019; 50:14. [PMID: 30777130 PMCID: PMC6380033 DOI: 10.1186/s13567-019-0632-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 01/03/2019] [Indexed: 12/31/2022] Open
Abstract
Piscine orthoreovirus (PRV) mediated diseases have emerged throughout salmonid aquaculture. Three PRV subtypes are currently reported as causative agents of or in association with diseases in different salmonid species. PRV-1 causes heart and skeletal muscle inflammation (HSMI) in Atlantic salmon (Salmo salar) and is associated with jaundice syndrome in farmed chinook salmon (Oncorhynchus tshawytscha). PRV-2 causes erythrocytic inclusion body syndrome (EIBS) in coho salmon in Japan. PRV-3 has recently been associated with a disease in rainbow trout (Oncorhynchus mykiss) characterized by anaemia, heart and red muscle pathology; to jaundice syndrome in coho salmon (Oncorhynchus kisutch). In this study, we conducted a 10-week long experimental infection trial in rainbow trout with purified PRV-3 particles to assess the causal relationship between the virus and development of heart inflammation. The monitoring the PRV-3 load in heart and spleen by RT-qPCR shows a progressive increase of viral RNA to a peak, followed by clearance without a measurable change in haematocrit. The development of characteristic cardiac histopathological findings occurred in the late phase of the trial and was associated with increased expression of CD8+, indicating cytotoxic T cell proliferation. The findings indicate that, under these experimental conditions, PRV-3 infection in rainbow trout act similarly to PRV-1 infection in Atlantic salmon with regards to immunological responses and development of heart pathology, but not in the ability to establish a persistent infection.
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Affiliation(s)
- Niccoló Vendramin
- National Institute of Aquatic Resources, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Dhamotharan Kannimuthu
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | | | - Argelia Cuenca
- National Institute of Aquatic Resources, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Lena Hammerlund Teige
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Øystein Wessel
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Tine Moesgaard Iburg
- National Institute of Aquatic Resources, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Niels Jørgen Olesen
- National Institute of Aquatic Resources, Technical University of Denmark, Kongens Lyngby, Denmark
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37
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Kibenge FS. Emerging viruses in aquaculture. Curr Opin Virol 2019; 34:97-103. [PMID: 30711892 DOI: 10.1016/j.coviro.2018.12.008] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 12/23/2018] [Accepted: 12/28/2018] [Indexed: 11/25/2022]
Abstract
Aquaculture remains the world's fastest-growing sector producing food of animal origin. Unlike in terrestrial animal agriculture, in aquaculture both farmed and wild aquatic animals in the same water column experience the same virus challenges. Additionally, the burgeoning international aquaculture expansion and expanding global trade in live aquatic animals and their products have been accompanied by long distance geographical redistribution of aquatic animal species and their viruses. The outcome is a continuous emergence of viral diseases in aquaculture, which may be driven by virus factors, animal host factors, environmental factors, and/or anthropogenic factors. Examples of emerging viruses in aquaculture include viral haemorrhagic septicaemia virus, infectious haematopoietic necrosis virus, infectious salmon anaemia virus, piscine orthoreovirus, Tilapia lake virus, Covert mortality nodavirus, Shrimp hemocyte iridescent virus, and Abalone herpesvirus.
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Affiliation(s)
- Frederick Sb 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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38
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Piscine Orthoreovirus 3 Is Not the Causative Pathogen of Proliferative Darkening Syndrome (PDS) of Brown Trout ( Salmo trutta fario). Viruses 2019; 11:v11020112. [PMID: 30696111 PMCID: PMC6410266 DOI: 10.3390/v11020112] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 01/18/2019] [Accepted: 01/25/2019] [Indexed: 12/17/2022] Open
Abstract
The proliferative darkening syndrome (PDS) is a lethal disease of brown trout (Salmo trutta fario) which occurs in several alpine Bavarian limestone rivers. Because mortality can reach 100%, PDS is a serious threat for affected fish populations. Recently, Kuehn and colleagues reported that a high throughput RNA sequencing approach identified a piscine orthoreovirus (PRV) as a causative agent of PDS. We investigated samples from PDS-affected fish obtained from two exposure experiments performed at the river Iller in 2008 and 2009. Using a RT-qPCR and a well-established next-generation RNA sequencing pipeline for pathogen detection, PRV-specific RNA was not detectable in PDS fish from 2009. In contrast, PRV RNA was readily detectable in several organs from diseased fish in 2008. However, similar virus loads were detectable in the control fish which were not exposed to Iller water and did not show any signs of the disease. Therefore, we conclude that PRV is not the causative agent of PDS of brown trout in the rhithral region of alpine Bavarian limestone rivers. The abovementioned study by Kuehn used only samples from the exposure experiment from 2008 and detected a subclinical PRV bystander infection. Work is ongoing to identify the causative agent of PDS.
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39
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Wessel Ø, Krasnov A, Timmerhaus G, Rimstad E, Dahle MK. Antiviral Responses and Biological Concequences of Piscine orthoreovirus Infection in Salmonid Erythrocytes. Front Immunol 2019; 9:3182. [PMID: 30700987 PMCID: PMC6343427 DOI: 10.3389/fimmu.2018.03182] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 12/27/2018] [Indexed: 11/13/2022] Open
Abstract
Salmonid red blood cells are the main target cells for Piscine orthoreovirus (PRV). Three genotypes of PRV (PRV-1,2,3) infect Atlantic salmon (Salmo salar), Chinook salmon (Onchorhynchus tshawytscha), Coho salmon (Oncorhynchus kisutch), rainbow trout (Onchorhynchus mykiss) and brown trout (Salmo trutta), and can cause diseases like heart and skeletal muscle inflammation (HSMI), jaundice syndrome, erythrocyte inclusion body syndrome (EIBS) and proliferative darkening syndrome (PDS). Purified PRV administrated to fish has proven the causality for HSMI and EIBS. During the early peak phase of infection, salmonid erythrocytes are the main virus-replicating cells. In this initial phase, cytoplasmic inclusions called "virus factories" can be observed in the erythrocytes, and are the primary sites for the formation of new virus particles. The PRV-infected erythrocytes in Atlantic salmon mount a strong long-lasting innate antiviral response lasting for many weeks after the onset of infection. The antiviral response of Atlantic salmon erythrocytes involves upregulation of potential inhibitors of translation. In accordance with this, PRV-1 protein production in erythrocytes halts while virus RNA can persist for months. Furthermore, PRV infection in Coho salmon and rainbow trout are associated with anemia, and in Atlantic salmon lower hemoglobin levels are observed. Here we summarize and discuss the recently published findings on PRV infection, replication and effects on salmonid erythrocytes, and discuss how PRV can be a useful tool for the study of innate immune responses in erythrocytes, and help reveal novel immune functions of the red blood cells in fish.
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Affiliation(s)
- Øystein Wessel
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Aleksei Krasnov
- Division of Aquaculture, Norwegian Institute of Fisheries and Aquaculture (Nofima), Tromsø, Norway
| | - Gerrit Timmerhaus
- Division of Aquaculture, Norwegian Institute of Fisheries and Aquaculture (Nofima), Tromsø, Norway
| | - Espen Rimstad
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Maria K Dahle
- Department of Fish Health, Norwegian Veterinary Institute, Oslo, Norway.,The Norwegian College of Fishery Science, UiT The Arctic University of Norway, Tromsø, Norway
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40
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Adamek M, Hellmann J, Flamm A, Teitge F, Vendramin N, Fey D, Riße K, Blakey F, Rimstad E, Steinhagen D. Detection of piscine orthoreoviruses (PRV-1 and PRV-3) in Atlantic salmon and rainbow trout farmed in Germany. Transbound Emerg Dis 2018; 66:14-21. [PMID: 30230250 DOI: 10.1111/tbed.13018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 08/06/2018] [Accepted: 09/06/2018] [Indexed: 01/10/2023]
Abstract
Piscine orthoreoviruses (PRVs) are emerging pathogens causing circulatory disorders in salmonids. PRV-1 is the etiological cause of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar), characterized by epicarditis, inflammation and necrosis of the myocardium, myositis and necrosis of red skeletal muscle. In 2017, two German breeding farms for Atlantic salmon and rainbow trout (Oncorhynchus mykiss) experienced disease outbreaks with mortalities of 10% and 20% respectively. The main clinical signs were exhaustion and lethargic behaviour. During examinations, PRV-1 in salmon and PRV-3 in trout were detected for the first time in Germany. Further analyses also indicated the presence of Aeromonas salmonicida in internal tissues of both species. While PRV-1 could be putatively linked with the disease in Atlantic salmon, most of the rainbow trout suffered from an infection with A. salmonicida and not with PRV-3. Interestingly, the sequence analysis suggests that the German PRV-3 isolate is more similar to a Chilean PRV-3 isolate from Coho salmon (Oncorhynchus kisutch) than to PRV-3 from rainbow trout from Norway. This indicates a wide geographic distribution of this virus or dispersal by global trade. These findings indicate that infections with PRVs should be considered when investigating disease outbreaks in salmonids.
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Affiliation(s)
- Mikolaj Adamek
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine, Hannover, Germany
| | - John Hellmann
- Department Fisheries Ecology, North Rhine Westphalian State Agency for Nature, Environment and Consumer Protection, Albaum, Germany
| | - Agnes Flamm
- Hesse State Laboratory, Control of Fish Diseases, Giessen, Germany
| | - Felix Teitge
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine, Hannover, Germany
| | - Niccolò Vendramin
- Fish Diseases, Division for Diagnostics & Scientific Advice, National Veterinary Institute, Technical University of Denmark, Lyngby, Denmark
| | - Daniel Fey
- Department Fisheries Ecology, North Rhine Westphalian State Agency for Nature, Environment and Consumer Protection, Albaum, Germany
| | - Karin Riße
- Hesse State Laboratory, Control of Fish Diseases, Giessen, Germany
| | - Franziska Blakey
- Hesse State Laboratory, Control of Fish Diseases, Giessen, Germany
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Dieter Steinhagen
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine, Hannover, Germany
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41
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Haatveit HM, Hodneland K, Braaen S, Hansen EF, Nyman IB, Dahle MK, Frost P, Rimstad E. DNA vaccine expressing the non-structural proteins of Piscine orthoreovirus delay the kinetics of PRV infection and induces moderate protection against heart -and skeletal muscle inflammation in Atlantic salmon (Salmo salar). Vaccine 2018; 36:7599-7608. [PMID: 30392768 DOI: 10.1016/j.vaccine.2018.10.094] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 10/23/2018] [Accepted: 10/30/2018] [Indexed: 01/08/2023]
Abstract
Piscine orthoreovirus (PRV) causes heart- and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar). Erythrocytes are the main target cells for PRV. HSMI causes significant economic losses to the salmon aquaculture industry, and there is currently no vaccine available. PRV replicates and assembles within cytoplasmic structures called viral factories, mainly organized by the non-structural viral protein µNS. In two experimental vaccination trials in Atlantic salmon, using DNA vaccines expressing different combinations of PRV proteins, we found that expression of the non-structural proteins µNS combined with the cell attachment protein σ1 was associated with an increasing trend in lymphocyte marker gene expression in spleen, and induced moderate protective effect against HSMI.
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Affiliation(s)
- Hanne M Haatveit
- Department of Food Safety and Infectious Biology, Norwegian University of Life Sciences, 0454 Oslo, Norway
| | | | - Stine Braaen
- Department of Food Safety and Infectious Biology, Norwegian University of Life Sciences, 0454 Oslo, Norway
| | - Elisabeth F Hansen
- Department of Food Safety and Infectious Biology, Norwegian University of Life Sciences, 0454 Oslo, Norway
| | - Ingvild B Nyman
- Department of Food Safety and Infectious Biology, Norwegian University of Life Sciences, 0454 Oslo, Norway
| | | | | | - Espen Rimstad
- Department of Food Safety and Infectious Biology, Norwegian University of Life Sciences, 0454 Oslo, Norway.
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42
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Kuehn R, Stoeckle BC, Young M, Popp L, Taeubert JE, Pfaffl MW, Geist J. Identification of a piscine reovirus-related pathogen in proliferative darkening syndrome (PDS) infected brown trout (Salmo trutta fario) using a next-generation technology detection pipeline. PLoS One 2018; 13:e0206164. [PMID: 30346982 PMCID: PMC6197672 DOI: 10.1371/journal.pone.0206164] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 10/08/2018] [Indexed: 01/02/2023] Open
Abstract
The proliferative darkening syndrome (PDS) is an annually recurring disease that causes species-specific die-off of brown trout (Salmo trutta fario) with a mortality rate of near 100% in pre-alpine rivers of central Europe. So far the etiology and causation of this disease is still unclear. The objective of this study was to identify the cause of PDS using a next-generation technology detection pipeline. Following the hypothesis that PDS is caused by an infectious agent, brown trout specimens were exposed to water from a heavily affected pre-alpine river with annual occurrence of the disease. Specimens were sampled over the entire time period from potential infection through death. Transcriptomic analysis (microarray) and RT-qPCR of brown trout liver tissue evidenced strong gene expression response of immune-associated genes. Messenger RNA of specimens with synchronous immune expression profiles were ultra-deep sequenced using next-generation sequencing technology (NGS). Bioinformatic processing of generated reads and gap-filling Sanger re-sequencing of the identified pathogen genome revealed strong evidence that a piscine-related reovirus is the causative organism of PDS. The identified pathogen is phylogenetically closely related to the family of piscine reoviruses (PRV) which are considered as the causation of different fish diseases in Atlantic and Pacific salmonid species such as Salmo salar and Onchorhynchus kisutch. This study also highlights that the approach of first screening immune responses along a timeline in order to identify synchronously affected stages in different specimens which subsequently were ultra-deep sequenced is an effective approach in pathogen detection. In particular, the identification of specimens with synchronous molecular immune response patterns combined with NGS sequencing and gap-filling re-sequencing resulted in the successful pathogen detection of PDS.
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Affiliation(s)
- Ralph Kuehn
- Unit of Molecular Zoology, Department of Zoology, Technical University of Munich, Freising, Germany.,Department of Fish, Wildlife and Conservation Ecology, New Mexico State University, Las Cruces, NM, United States of America
| | - Bernhard C Stoeckle
- Unit of Molecular Zoology, Department of Zoology, Technical University of Munich, Freising, Germany.,Aquatic Systems Biology Unit, Department of Ecology and Ecosystem Management, Technical University of Munich, Freising, Germany
| | - Marc Young
- Unit of Molecular Zoology, Department of Zoology, Technical University of Munich, Freising, Germany
| | - Lisa Popp
- Unit of Molecular Zoology, Department of Zoology, Technical University of Munich, Freising, Germany
| | - Jens-Eike Taeubert
- Fachberatung für Fischerei Niederbayern, Bezirk Niederbayern, Landshut, Germany
| | - Michael W Pfaffl
- Department of Animal Physiology and Immunology, Technical University of Munich, Freising, Germany
| | - Juergen Geist
- Aquatic Systems Biology Unit, Department of Ecology and Ecosystem Management, Technical University of Munich, Freising, Germany
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43
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Di Cicco E, Ferguson HW, Kaukinen KH, Schulze AD, Li S, Tabata A, Günther OP, Mordecai G, Suttle CA, Miller KM. The same strain of Piscine orthoreovirus (PRV-1) is involved in the development of different, but related, diseases in Atlantic and Pacific Salmon in British Columbia. Facets (Ott) 2018. [DOI: 10.1139/facets-2018-0008] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Piscine orthoreovirus Strain PRV-1 is the causative agent of heart and skeletal muscle inflammation (HSMI) in Atlantic salmon ( Salmo salar Linnaeus, 1758). Given its high prevalence in net pen salmon, debate has arisen on whether PRV poses a risk to migratory salmon, especially in British Columbia (BC) where commercially important wild Pacific salmon are in decline. Various strains of PRV have been associated with diseases in Pacific salmon, including erythrocytic inclusion body syndrome (EIBS), HSMI-like disease, and jaundice/anemia in Japan, Norway, Chile and Canada. We examined the developmental pathway of HSMI and jaundice/anemia associated with PRV-1 in farmed Atlantic and chinook ( Oncorhynchus tshawytscha (Walbaum, 1792)) salmon in BC, respectively. In situ hybridization localized PRV-1 within developing lesions in both diseases. The two diseases showed dissimilar pathological pathways, with inflammatory lesions in heart and skeletal muscle in Atlantic salmon and degenerative-necrotic lesions in kidney and liver in chinook salmon, plausibly explained by differences in PRV load tolerance in red blood cells. Viral genome sequencing revealed no consistent differences in PRV-1 variants intimately involved in the development of both diseases suggesting that migratory chinook salmon may be at more than a minimal risk of disease from exposure to the high levels of PRV occurring in salmon farms.
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Affiliation(s)
- Emiliano Di Cicco
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7, Canada
- Pacific Salmon Foundation, Vancouver, BC V6J 4S6, Canada
| | - Hugh W. Ferguson
- School of Veterinary Medicine, St. George’s University, True Blue, Grenada, West Indies
| | - Karia H. Kaukinen
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7, Canada
| | - Angela D. Schulze
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7, Canada
| | - Shaorong Li
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7, Canada
| | - Amy Tabata
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7, Canada
| | | | - Gideon Mordecai
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Curtis A. Suttle
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- Department of Microbiology and Immunology, Department of Botany, Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Kristina M. Miller
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7, Canada
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First Complete Genome Sequence of Piscine Orthoreovirus Variant 3 Infecting Coho Salmon (Oncorhynchus kisutch) Farmed in Southern Chile. GENOME ANNOUNCEMENTS 2018; 6:6/24/e00484-18. [PMID: 29903813 PMCID: PMC6003745 DOI: 10.1128/genomea.00484-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report here the complete genome of an isolate of piscine orthoreovirus variant 3 sequenced from a moribund coho salmon with jaundice that was reared in a seawater farm in southern Chile. The genome consists of 23,627 bp, including 10 segments that range from 1,052 bp (segment S4) to 4,014 bp (segment L1).
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Distinct seasonal infectious agent profiles in life-history variants of juvenile Fraser River Chinook salmon: An application of high-throughput genomic screening. PLoS One 2018; 13:e0195472. [PMID: 29672620 PMCID: PMC5908190 DOI: 10.1371/journal.pone.0195472] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 03/25/2018] [Indexed: 11/19/2022] Open
Abstract
Disease-causing infectious agents are natural components of ecosystems and considered a major selective force driving the evolution of host species. However, knowledge of the presence and abundance of suites of infectious agents in wild populations has been constrained by our ability to easily screen for them. Using salmon as a model, we contrasted seasonal pathogenic infectious agents in life history variants of juvenile Chinook salmon from the Fraser River system (N = 655), British Columbia (BC), through the application of a novel high-throughput quantitative PCR monitoring platform. This included freshwater hatchery origin fish and samples taken at sea between ocean entry in spring and over-winter residence in coastal waters. These variants currently display opposite trends in productivity, with yearling stocks generally in decline and sub-yearling stocks doing comparatively well. We detected the presence of 32 agents, 21 of which were at >1% prevalence. Variants carried a different infectious agent profile in terms of (1) diversity, (2) origin or transmission environment of infectious agents, and (3) prevalence and abundance of individual agents. Differences in profiles tended to reflect differential timing and residence patterns through freshwater, estuarine and marine habitats. Over all seasons, individual salmon carried an average of 3.7 agents. Diversity changed significantly, increasing upon saltwater entrance, increasing through the fall and decreasing slightly in winter. Diversity varied between life history types with yearling individuals carrying 1.3-times more agents on average. Shifts in prevalence and load over time were examined to identify agents with the greatest potential for impact at the stock level; those displaying concurrent decrease in prevalence and load truncation with time. Of those six that had similar patterns in both variants, five reached higher prevalence in yearling fish while only one reached higher prevalence in sub-yearling fish; this pattern was present for an additional five agents in yearling fish only.
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Molecular and Antigenic Characterization of Piscine orthoreovirus (PRV) from Rainbow Trout (Oncorhynchus mykiss). Viruses 2018; 10:v10040170. [PMID: 29614838 PMCID: PMC5923464 DOI: 10.3390/v10040170] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 03/23/2018] [Accepted: 03/28/2018] [Indexed: 01/01/2023] Open
Abstract
Piscine orthoreovirus (PRV-1) causes heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar). Recently, a novel PRV (formerly PRV-Om, here called PRV-3), was found in rainbow trout (Oncorhynchus mykiss) with HSMI-like disease. PRV is considered to be an emerging pathogen in farmed salmonids. In this study, molecular and antigenic characterization of PRV-3 was performed. Erythrocytes are the main target cells for PRV, and blood samples that were collected from experimentally challenged fish were used as source of virus. Virus particles were purified by gradient ultracentrifugation and the complete coding sequences of PRV-3 were obtained by Illumina sequencing. When compared to PRV-1, the nucleotide identity of the coding regions was 80.1%, and the amino acid identities of the predicted PRV-3 proteins varied from 96.7% (λ1) to 79.1% (σ3). Phylogenetic analysis showed that PRV-3 belongs to a separate cluster. The region encoding σ3 were sequenced from PRV-3 isolates collected from rainbow trout in Europe. These sequences clustered together, but were distant from PRV-3 that was isolated from rainbow trout in Norway. Bioinformatic analyses of PRV-3 proteins revealed that predicted secondary structures and functional domains were conserved between PRV-3 and PRV-1. Rabbit antisera raised against purified virus or various recombinant virus proteins from PRV-1 all cross-reacted with PRV-3. Our findings indicate that despite different species preferences of the PRV subtypes, several genetic, antigenic, and structural properties are conserved between PRV-1 and-3.
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Purcell MK, Powers RL, Evered J, Kerwin J, Meyers TR, Stewart B, Winton JR. Molecular testing of adult Pacific salmon and trout (Oncorhynchus spp.) for several RNA viruses demonstrates widespread distribution of piscine orthoreovirus in Alaska and Washington. JOURNAL OF FISH DISEASES 2018; 41:347-355. [PMID: 29159930 DOI: 10.1111/jfd.12740] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 06/07/2023]
Abstract
This research was initiated in conjunction with a systematic, multiagency surveillance effort in the United States (U.S.) in response to reported findings of infectious salmon anaemia virus (ISAV) RNA in British Columbia, Canada. In the systematic surveillance study reported in a companion paper, tissues from various salmonids taken from Washington and Alaska were surveyed for ISAV RNA using the U.S.-approved diagnostic method, and samples were released for use in this present study only after testing negative. Here, we tested a subset of these samples for ISAV RNA with three additional published molecular assays, as well as for RNA from salmonid alphavirus (SAV), piscine myocarditis virus (PMCV) and piscine orthoreovirus (PRV). All samples (n = 2,252; 121 stock cohorts) tested negative for RNA from ISAV, PMCV, and SAV. In contrast, there were 25 stock cohorts from Washington and Alaska that had one or more individuals test positive for PRV RNA; prevalence within stocks varied and ranged from 2% to 73%. The overall prevalence of PRV RNA-positive individuals across the study was 3.4% (77 of 2,252 fish tested). Findings of PRV RNA were most common in coho (Oncorhynchus kisutch Walbaum) and Chinook (O. tshawytscha Walbaum) salmon.
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Affiliation(s)
- M K Purcell
- U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA, USA
| | - R L Powers
- U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA, USA
| | - J Evered
- U.S. Fish and Wildlife Service, Olympia Fish Health Center, Lacey, WA, USA
| | - J Kerwin
- Washington Department of Fish and Wildlife, Olympia, WA, USA
| | - T R Meyers
- Division of Commercial Fisheries, Alaska Department of Fish and Game, Juneau, AK, USA
| | - B Stewart
- Northwest Indian Fisheries Commission, Olympia, WA, USA
| | - J R Winton
- U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA, USA
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Morton A, Routledge R, Hrushowy S, Kibenge M, Kibenge F. The effect of exposure to farmed salmon on piscine orthoreovirus infection and fitness in wild Pacific salmon in British Columbia, Canada. PLoS One 2017; 12:e0188793. [PMID: 29236731 PMCID: PMC5728458 DOI: 10.1371/journal.pone.0188793] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 11/13/2017] [Indexed: 12/29/2022] Open
Abstract
The disease Heart and Skeletal Muscle Inflammation (HSMI) is causing substantial economic losses to the Norwegian salmon farming industry where the causative agent, piscine orthoreovirus (PRV), is reportedly spreading from farmed to wild Atlantic salmon (Salmo salar) with as yet undetermined impacts. To assess if PRV infection is epidemiologically linked between wild and farmed salmon in the eastern Pacific, wild Pacific salmon (Oncorhynchus sp.) from regions designated as high or low exposure to salmon farms and farmed Atlantic salmon reared in British Columbia (BC) were tested for PRV. The proportion of PRV infection in wild fish was related to exposure to salmon farms (p = 0.0097). PRV was detected in: 95% of farmed Atlantic salmon, 37-45% of wild salmon from regions highly exposed to salmon farms and 5% of wild salmon from the regions furthest from salmon farms. The proportion of PRV infection was also significantly lower (p = 0.0008) where wild salmon had been challenged by an arduous return migration into high-elevation spawning habitat. Inter-annual PRV infection declined in both wild and farmed salmon from 2012-2013 (p ≤ 0.002). These results suggest that PRV transfer is occurring from farmed Atlantic salmon to wild Pacific salmon, that infection in farmed salmon may be influencing infection rates in wild salmon, and that this may pose a risk of reduced fitness in wild salmon impacting their survival and reproduction.
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Affiliation(s)
- Alexandra Morton
- Raincoast Research Society, Sointula, British Columbia, Canada
- * E-mail:
| | - Richard Routledge
- Department of Statistics and Actuarial Science, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Stacey Hrushowy
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Molly Kibenge
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Frederick Kibenge
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
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Kibenge MJT, Wang Y, Morton A, Routledge R, Kibenge FSB. Formal comment on: Piscine reovirus: Genomic and molecular phylogenetic analysis from farmed and wild salmonids collected on the Canada/US Pacific Coast. PLoS One 2017; 12:e0188690. [PMID: 29190697 PMCID: PMC5708765 DOI: 10.1371/journal.pone.0188690] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 10/31/2017] [Indexed: 11/18/2022] Open
Affiliation(s)
- Molly J. T. Kibenge
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Yingwei Wang
- School of Mathematical and Computational Sciences, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | | | - Richard Routledge
- Department of Statistics and Actuarial Science, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Frederick S. B. Kibenge
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
- * E-mail:
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Wessel Ø, Braaen S, Alarcon M, Haatveit H, Roos N, Markussen T, Tengs T, Dahle MK, Rimstad E. Infection with purified Piscine orthoreovirus demonstrates a causal relationship with heart and skeletal muscle inflammation in Atlantic salmon. PLoS One 2017; 12:e0183781. [PMID: 28841684 PMCID: PMC5571969 DOI: 10.1371/journal.pone.0183781] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 08/10/2017] [Indexed: 01/07/2023] Open
Abstract
Viral diseases pose a significant threat to the productivity in aquaculture. Heart- and skeletal muscle inflammation (HSMI) is an emerging disease in Atlantic salmon (Salmo salar) farming. HSMI is associated with Piscine orthoreovirus (PRV) infection, but PRV is ubiquitous in farmed Atlantic salmon and thus present also in apparently healthy individuals. This has brought speculations if additional etiological factors are required, and experiments focusing on the causal relationship between PRV and HSMI are highly warranted. A major bottleneck in PRV research has been the lack of cell lines that allow propagation of the virus. To bypass this, we propagated PRV in salmon, bled the fish at the peak of the infection, and purified virus particles from blood cells. Electron microscopy, western blot and high-throughput sequencing all verified the purity of the viral particles. Purified PRV particles were inoculated into naïve Atlantic salmon. The purified virus replicated in inoculated fish, spread to naïve cohabitants, and induced histopathological changes consistent with HSMI. PRV specific staining was demonstrated in the pathological lesions. A dose-dependent response was observed; a high dose of virus gave earlier peak of the viral load and development of histopathological changes compared to a lower dose, but no difference in the severity of the disease. The experiment demonstrated that PRV can be purified from blood cells, and that PRV is the etiological agent of HSMI in Atlantic salmon.
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Affiliation(s)
- Øystein Wessel
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
- * E-mail:
| | - Stine Braaen
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | | | - Hanne Haatveit
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Norbert Roos
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Turhan Markussen
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Torstein Tengs
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | | | - Espen Rimstad
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
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