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Rounsville TF, Polinski MP, Marini AG, Turner SM, Vendramin N, Cuenca A, Pietrak MR, Peterson BC, Bouchard DA. Rapid differentiation of infectious salmon anemia virus avirulent (HPR0) from virulent (HPRΔ) variants using multiplex RT-qPCR. J Vet Diagn Invest 2024; 36:329-337. [PMID: 38212882 PMCID: PMC11110766 DOI: 10.1177/10406387231223290] [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: 01/13/2024] Open
Abstract
Infectious salmon anemia virus (ISAV; Isavirus salaris) causes an economically important disease of Atlantic salmon (Salmo salar L.). ISA outbreaks have resulted in significant losses of farmed salmon globally, often with a sudden onset. However, 2 phenotypically distinct variants of ISAV exist, each with divergent disease outcomes, associated regulations, and control measures. ISAV-HPRΔ, also known as ISAV-HPR deleted, is responsible for ISA outbreaks; ISAV-HPR0, is avirulent and is not known to cause fish mortality. Current detection methodology requires genetic sequencing of ISAV-positive samples to differentiate phenotypes, which may slow responses to disease management. To increase the speed of phenotypic determinations of ISAV, we developed a new, rapid multiplex RT-qPCR method capable of 1) detecting if a sample contains any form of ISAV, 2) discriminating whether positive samples contain HPRΔ or HPR0, and 3) validating RNA extractions with an internal control, all in a single reaction. Following assay development and optimization, we validated this new multiplex on 31 ISAV strains collected from North America and Europe (28 ISAV-HPRΔ, 3 ISAV-HPR0). Finally, we completed an inter-laboratory comparison of this multiplex qPCR with commercial ISAV testing and found that both methods provided equivalent results for ISAV detection.
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Affiliation(s)
- Thomas F. Rounsville
- Pest Management Unit, University of Maine Cooperative Extension Diagnostic and Research Laboratory, Orono, ME, USA
| | - Mark P. Polinski
- National Cold Water Marine Aquaculture Center, U.S. Department of Agriculture–Agricultural Research Service, Franklin, ME, USA
| | - Alyssa G. Marini
- Pest Management Unit, University of Maine Cooperative Extension Diagnostic and Research Laboratory, Orono, ME, USA
- University of Maine School of Biology and Ecology, Orono, ME, USA
| | - Sarah M. Turner
- Aquatic Animal Health Laboratory, University of Maine Cooperative Extension Diagnostic and Research Laboratory, Orono, ME, USA
| | - Niccolò Vendramin
- Unit for Fish and Shellfish Diseases, National Institute of Aquatic Resources, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Argelia Cuenca
- Unit for Fish and Shellfish Diseases, National Institute of Aquatic Resources, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Michael R. Pietrak
- National Cold Water Marine Aquaculture Center, U.S. Department of Agriculture–Agricultural Research Service, Franklin, ME, USA
| | - Brian C. Peterson
- National Cold Water Marine Aquaculture Center, U.S. Department of Agriculture–Agricultural Research Service, Franklin, ME, USA
| | - Deborah A. Bouchard
- Aquatic Animal Health Laboratory, University of Maine Cooperative Extension Diagnostic and Research Laboratory, Orono, ME, USA
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Ford CE, Dunn CD, Leis EM, Thiel WA, Goldberg TL. Five Species of Wild Freshwater Sport Fish in Wisconsin, USA, Reveal Highly Diverse Viromes. Pathogens 2024; 13:150. [PMID: 38392888 PMCID: PMC10891596 DOI: 10.3390/pathogens13020150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/01/2024] [Accepted: 02/05/2024] [Indexed: 02/25/2024] Open
Abstract
Studies of marine fish have revealed distant relatives of viruses important to global fish and animal health, but few such studies exist for freshwater fish. To investigate whether freshwater fish also host such viruses, we characterized the viromes of five wild species of freshwater fish in Wisconsin, USA: bluegill (Lepomis macrochirus), brown trout (Salmo trutta), lake sturgeon (Acipenser fulvescens), northern pike (Esox lucius), and walleye (Sander vitreus). We analyzed 103 blood serum samples collected during a state-wide survey from 2016 to 2020 and used a metagenomic approach for virus detection to identify known and previously uncharacterized virus sequences. We then characterized viruses phylogenetically and quantified prevalence, richness, and relative abundance for each virus. Within these viromes, we identified 19 viruses from 11 viral families: Amnoonviridae, Circoviridae, Coronaviridae, Hepadnaviridae, Peribunyaviridae, Picobirnaviridae, Picornaviridae, Matonaviridae, Narnaviridae, Nudnaviridae, and Spinareoviridae, 17 of which were previously undescribed. Among these viruses was the first fish-associated coronavirus from the Gammacoronavirus genus, which was present in 11/15 (73%) of S. vitreus. These results demonstrate that, similar to marine fish, freshwater fish also harbor diverse relatives of viruses important to the health of fish and other animals, although it currently remains unknown what effect, if any, the viruses we identified may have on fish health.
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Affiliation(s)
- Charlotte E. Ford
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (C.E.F.); (C.D.D.)
| | - Christopher D. Dunn
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (C.E.F.); (C.D.D.)
| | - Eric M. Leis
- U.S. Fish and Wildlife Service, La Crosse Fish Health Center—Midwest Fisheries Center, Onalaska, WI 54650, USA;
| | - Whitney A. Thiel
- Robert P. Hanson Laboratories, University of Wisconsin-Madison, Madison, WI 53706, USA;
| | - Tony L. Goldberg
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (C.E.F.); (C.D.D.)
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Groves L, Whyte SK, Purcell SL, Michaud D, Cai WC, Garber AF, Fast MD. Temperature impacts Atlantic salmon's ( Salmo salar) immunological response to infectious salmon anemia virus (ISAv). FISH AND SHELLFISH IMMUNOLOGY REPORTS 2023; 4:100099. [PMID: 37293549 PMCID: PMC10245120 DOI: 10.1016/j.fsirep.2023.100099] [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: 03/15/2023] [Revised: 05/20/2023] [Accepted: 05/21/2023] [Indexed: 06/10/2023] Open
Abstract
Ocean temperatures continue to rise annually due to the ever-growing consequences of global climate change. These temperature changes can have an impact on the immunological robustness of cultured fish, especially cold-water species such as Atlantic salmon. The salmon farming industry already loses hundreds of millions of dollars each year to infectious and non-infectious diseases. One particularly important and WOAH reportable disease is infectious salmon anemia caused by the orthomyxovirus ISAv. Considering the changing environment, it is necessary to find ways to mitigate the effect of diseases on the industry. For this study, 20 Atlantic salmon families were housed in each of 38 different tanks at the AVC, with half of the fish being kept at 10 °C and half being kept at 20 °C. Donor Atlantic salmon IP- injected with a highly virulent ISAv isolate (HPR4; TCID50 of 1 × 105/mL) were added to each tank as the source of co-habitation infection. Both temperatures were sampled at onset of mortality in co-habited fish and at resolution of mortality. Family background and temperature significantly impacted ISAv load, as assessed by qPCR, time to mortality and overall mortality. Mortality was more acute at 20 °C, but overall mortality was higher at 10 °C. Based on percent mortality calculated over the course of the study, different families demonstrated different levels of survival. The three families that demonstrated the highest percent mortality, and the three families with the lowest percent mortality were then assessed for their antiviral responses using relative gene expression. Genes significantly upregulated between the unexposed fish and ISAv exposed fish included mx1, il4/13a, il12rb2, and trim25, and these were further impacted by temperature. Understanding how ISAv resistance is impacted by temperature can help identify seasonal risks of ISAv outbreaks as well as ideal responses to be targeted through immunopotentiation.
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Affiliation(s)
- L Groves
- Hoplite Lab, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
| | - SK Whyte
- Hoplite Lab, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
| | - SL Purcell
- Hoplite Lab, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
| | - D Michaud
- Hoplite Lab, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
| | - WC Cai
- Hoplite Lab, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong SAR, China
| | - AF Garber
- Huntsman Marine Science Centre, St. Andrews, NB, Canada
| | - MD Fast
- Hoplite Lab, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
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Gautam M, Hammell KL, Burnley H, O'Brien N, Whelan D, Thakur KK. Description of spatiotemporal patterns of infectious salmon anemia virus (ISAV) detections in marine Atlantic Salmon farms in Newfoundland and Labrador. JOURNAL OF AQUATIC ANIMAL HEALTH 2023; 35:296-307. [PMID: 38124493 DOI: 10.1002/aah.10205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVE The objectives of this study were to describe spatiotemporal patterns of infectious salmon anemia virus (ISAV) detections in marine salmonid production sites in the province of Newfoundland and Labrador in Canada. METHODS Infectious salmon anemia virus surveillance data between 2012 and 2020 from the province of Newfoundland and Labrador were used. Data comprised a total of 94 sampling events from 20 Atlantic Salmon Salmo salar production sites in which ISAV was detected. Using linear regression models, factors influencing time to detection (days from stocking to first ISAV detection) and time to depopulation (days from first detection to production site depopulation) were investigated. RESULT Based on 28 unique cases, site-level annual incidence risk of ISAV detection ranged from 3% to 29%. The proportion of ISAV detection by PCR in fish samples ranged from 2% to 45% annually. Overall, ISAV variants from the European clade were more common than variants from the North American clade. The type of ISAV clade, detections of ISAV in nearest production sites based on seaway distances, and year of infectious salmon anemia cases were not associated with time to first ISAV detection. Time to depopulation for sites infected with the ISAV-HPRΔ variant was not associated with ISAV North American or European clades. CONCLUSION Our results contribute to the further understanding of the changing dynamics of infectious salmon anemia detections in Newfoundland and Labrador since its first detection in 2012 and will likely assist in the design of improved disease surveillance and control programs in the province.
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Affiliation(s)
- Milan Gautam
- Centre for Veterinary Epidemiological Research and Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - K Larry Hammell
- Centre for Veterinary Epidemiological Research and Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Holly Burnley
- Centre for Veterinary Epidemiological Research and Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Nicole O'Brien
- Department of Fisheries, Forestry and Agriculture, Aquatic Animal Health Division, St. John's, Newfoundland and Labrador, Canada
| | - Daryl Whelan
- Department of Fisheries, Forestry and Agriculture, Aquatic Animal Health Division, St. John's, Newfoundland and Labrador, Canada
| | - Krishna Kumar Thakur
- Centre for Veterinary Epidemiological Research and Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
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5
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Romero JF, Gardner IA, Hammell L, Groman D, Whelan D, O'Brien N, Hawkins LJ, Burnley H, Thakur K. Descriptive epidemiology of variants of infectious salmon anaemia virus in four Atlantic salmon farms in Newfoundland and Labrador, Canada. JOURNAL OF FISH DISEASES 2022; 45:919-930. [PMID: 35397120 DOI: 10.1111/jfd.13617] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/25/2022] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
Abstract
An incursion of infectious salmon anaemia virus (ISAV) was detected in 2020 in southern Newfoundland, Canada. This resulted in an outbreak affecting four marine farms stocking Atlantic salmon (Salmo salar L.) vaccinated against ISAV. This study provides the first description of epidemiologic characteristics of an ISAV outbreak in 2020 and 2021, and detected ISAV variants at the population level. Fish kidneys were screened for ISAV by real-time RT-PCR and non-negative samples were submitted for genotyping and further diagnostic testing. Nine distinct ISAV variants were identified: five European and three North American (NA) HPRΔ ISAV, and one NA-HPR0 ISAV variant. A notable finding was the concurrent detection of both an HPR0 and an HPRΔ ISAV variant in one individual fish. In two farms, both European and NA variants were simultaneously detected, while in the other two farms either NA or European variants were identified, but not both together. Generally, mortality increases followed rises in ISAV prevalence and cycle threshold values on RT-PCR decreased with time. Epidemiologic descriptions of ISAV outbreaks in Atlantic Canada contributes to the understanding of local disease dynamics and identification of changes thereof. Such insights are essential for the strengthening of disease management plans.
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Affiliation(s)
- João F Romero
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
- Centre for Veterinary Epidemiological Research, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Ian A Gardner
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
- Centre for Veterinary Epidemiological Research, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Larry Hammell
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
- Centre for Veterinary Epidemiological Research, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - David Groman
- Aquatic Diagnostic Services, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Daryl Whelan
- Department of Fisheries, Forestry and Agriculture, Aquatic Animal Health Division, St. John's, Newfoundland and Labrador, Canada
| | - Nicole O'Brien
- Department of Fisheries, Forestry and Agriculture, Aquatic Animal Health Division, St. John's, Newfoundland and Labrador, Canada
| | | | - Holly Burnley
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
- Centre for Veterinary Epidemiological Research, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Krishna Thakur
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
- Centre for Veterinary Epidemiological Research, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
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Ditlecadet D, Gautreau C, Boston L, Liston R, Johnsen E, Gagné N. First report of successful isolation of a HPR0-like variant of the infectious salmon anaemia virus (ISAV) using cell culture. JOURNAL OF FISH DISEASES 2022; 45:479-483. [PMID: 34843624 PMCID: PMC9299946 DOI: 10.1111/jfd.13556] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 11/03/2021] [Accepted: 11/04/2021] [Indexed: 06/13/2023]
Abstract
ISAV is the causative agent of the infectious salmon anaemia (ISA), a disease listed by the OIE that has caused important economic losses to the Atlantic salmon (Salmo salar) industry. ISAV variants are identified as pathogenic or non-pathogenic based on the presence or absence of a deletion in the highly polymorphic region (HPR) of segment 6 (S6). HPRΔ variants (pathogenic) are the only forms of the virus known to grow in cell culture. This is the first report of a HPR0 variant isolated in cell culture. The isolate is, however, atypical as it shows a marker of virulent variants on another segment (S5), which has never been reported for any other HPR0 variants. The significance of this finding remains unclear until more in-depth work is carried out but does challenge current knowledge.
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Affiliation(s)
- D. Ditlecadet
- Fisheries & Oceans CanadaGulf Fisheries CenterMonctonCanada
| | - C. Gautreau
- Fisheries & Oceans CanadaGulf Fisheries CenterMonctonCanada
| | - L. Boston
- Fisheries & Oceans CanadaGulf Fisheries CenterMonctonCanada
| | | | | | - N. Gagné
- Fisheries & Oceans CanadaGulf Fisheries CenterMonctonCanada
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Christiansen DH, Petersen PE, Dahl MM, Vest N, Aamelfot M, Kristoffersen AB, Jansen MD, Matejusova I, Gallagher MD, Jónsson G, Rodriguez E, Fosse JH, Falk K. No Evidence of the Vertical Transmission of Non-Virulent Infectious Salmon Anaemia Virus (ISAV-HPR0) in Farmed Atlantic Salmon. Viruses 2021; 13:v13122428. [PMID: 34960697 PMCID: PMC8708482 DOI: 10.3390/v13122428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 11/30/2022] Open
Abstract
The nonvirulent infectious salmon anaemia virus (ISAV-HPR0) is the putative progenitor for virulent-ISAV, and a potential risk factor for the development of infectious salmon anaemia (ISA). Understanding the transmission dynamics of ISAV-HPR0 is fundamental to proper management and mitigation strategies. Here, we demonstrate that ISAV-HPR0 causes prevalent and transient infections in all three production stages of Atlantic salmon in the Faroe Islands. Phylogenetic analysis of the haemagglutinin-esterase gene from 247 salmon showed a clear geographical structuring into two significantly distinct HPR0-subgroups, which were designated G2 and G4. Whereas G2 and G4 co-circulated in marine farms, Faroese broodfish were predominantly infected by G2, and smolt were predominantly infected by G4. This infection pattern was confirmed by our G2- and G4-specific RT-qPCR assays. Moreover, the HPR0 variants detected in Icelandic and Norwegian broodfish were never detected in the Faroe Islands, despite the extensive import of ova from both countries. Accordingly, the vertical transmission of HPR0 from broodfish to progeny is uncommon. Phylogenetic and statistical analysis suggest that HPR0 persists in the smolt farms as “house-strains”, and that new HPR0 variants are occasionally introduced from the marine environment, probably by HPR0-contaminated sea-spray. Thus, high biosecurity—including water and air intake—is required to avoid the introduction of pathogens to the smolt farms.
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Affiliation(s)
- Debes Hammershaimb Christiansen
- National Reference Laboratory for Fish and Animal Diseases, Faroese Food and Veterinary Authority, 110 Torshavn, Faroe Islands; (P.E.P.); (M.M.D.); (N.V.)
- Correspondence:
| | - Petra Elisabeth Petersen
- National Reference Laboratory for Fish and Animal Diseases, Faroese Food and Veterinary Authority, 110 Torshavn, Faroe Islands; (P.E.P.); (M.M.D.); (N.V.)
| | - Maria Marjunardóttir Dahl
- National Reference Laboratory for Fish and Animal Diseases, Faroese Food and Veterinary Authority, 110 Torshavn, Faroe Islands; (P.E.P.); (M.M.D.); (N.V.)
| | - Nicolina Vest
- National Reference Laboratory for Fish and Animal Diseases, Faroese Food and Veterinary Authority, 110 Torshavn, Faroe Islands; (P.E.P.); (M.M.D.); (N.V.)
| | - Maria Aamelfot
- Norwegian Veterinary Institute, 0454 Oslo, Norway; (M.A.); (A.B.K.); (M.D.J.); (J.H.F.); (K.F.)
| | | | - Mona Dverdal Jansen
- Norwegian Veterinary Institute, 0454 Oslo, Norway; (M.A.); (A.B.K.); (M.D.J.); (J.H.F.); (K.F.)
| | - Iveta Matejusova
- Marine Scotland Science, Marine Laboratory, Aberdeen AB11 9DB, UK;
| | - Michael D. Gallagher
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh EH8 9YL, UK;
| | - Gísli Jónsson
- Icelandic Food and Veterinary Authority, 220 Hafnarfjordur, Iceland;
| | | | - Johanna Hol Fosse
- Norwegian Veterinary Institute, 0454 Oslo, Norway; (M.A.); (A.B.K.); (M.D.J.); (J.H.F.); (K.F.)
| | - Knut Falk
- Norwegian Veterinary Institute, 0454 Oslo, Norway; (M.A.); (A.B.K.); (M.D.J.); (J.H.F.); (K.F.)
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Fosse JH, Haraldsen G, Falk K, Edelmann R. Endothelial Cells in Emerging Viral Infections. Front Cardiovasc Med 2021; 8:619690. [PMID: 33718448 PMCID: PMC7943456 DOI: 10.3389/fcvm.2021.619690] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 02/01/2021] [Indexed: 12/11/2022] Open
Abstract
There are several reasons to consider the role of endothelial cells in COVID-19 and other emerging viral infections. First, severe cases of COVID-19 show a common breakdown of central vascular functions. Second, SARS-CoV-2 replicates in endothelial cells. Third, prior deterioration of vascular function exacerbates disease, as the most common comorbidities of COVID-19 (obesity, hypertension, and diabetes) are all associated with endothelial dysfunction. Importantly, SARS-CoV-2's ability to infect endothelium is shared by many emerging viruses, including henipaviruses, hantavirus, and highly pathogenic avian influenza virus, all specifically targeting endothelial cells. The ability to infect endothelium appears to support generalised dissemination of infection and facilitate the access to certain tissues. The disturbed vascular function observed in severe COVID-19 is also a prominent feature of many other life-threatening viral diseases, underscoring the need to understand how viruses modulate endothelial function. We here review the role of vascular endothelial cells in emerging viral infections, starting with a summary of endothelial cells as key mediators and regulators of vascular and immune responses in health and infection. Next, we discuss endotheliotropism as a possible virulence factor and detail features that regulate viruses' ability to attach to and enter endothelial cells. We move on to review how endothelial cells detect invading viruses and respond to infection, with particular focus on pathways that may influence vascular function and the host immune system. Finally, we discuss how endothelial cell function can be dysregulated in viral disease, either by viral components or as bystander victims of overshooting or detrimental inflammatory and immune responses. Many aspects of how viruses interact with the endothelium remain poorly understood. Considering the diversity of such mechanisms among different emerging viruses allows us to highlight common features that may be of general validity and point out important challenges.
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Affiliation(s)
| | - Guttorm Haraldsen
- Department of Pathology, Oslo University Hospital, Oslo, Norway.,Department of Pathology, University of Oslo, Oslo, Norway
| | - Knut Falk
- Norwegian Veterinary Institute, Oslo, Norway.,AquaMed Consulting AS, Oslo, Norway
| | - Reidunn Edelmann
- Department of Clinical Medicine, Centre for Cancer Biomarkers CCBIO, University of Bergen, Bergen, Norway
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9
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Rimstad E, Markussen T. Infectious salmon anaemia virus-molecular biology and pathogenesis of the infection. J Appl Microbiol 2020; 129:85-97. [PMID: 31885186 DOI: 10.1111/jam.14567] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 11/29/2022]
Abstract
Aquaculture has a long history in many parts of the world, but it is still young at an industrial scale. Marine fish farming in open nets of a single fish species at high densities compared to their wild compatriots opens a plethora of possible infections. Infectious salmon anaemia (ISA) is an example of disease that surfaced after large-scale farming of Atlantic salmon (Salmo salar) appeared. Here, a review of the molecular biology of the ISA virus (ISAV) with emphasis on its pathogenicity is presented. The avirulent HPR0 variant of ISAV has resisted propagation in cell cultures, which has restricted the ability to perform in vivo experiments with this variant. The transition from avirulent HPR0 to virulent HPRΔ has not been methodically studied under controlled experimental conditions, and the triggers of the transition from avirulent to virulent forms have not been mapped. Genetic segment reassortment, recombination and mutations are important mechanisms in ISAV evolution, and for the development of virulence. In the 25 years since the ISAV was identified, large amounts of sequence data have been collected for epidemiologic and transmission studies, however, the lack of good experimental models for HPR0 make the risk evaluation of the presence of this avirulent, ubiquitous variant uncertain. This review summarizes the current knowledge related to molecular biology and pathogenicity of this important aquatic orthomyxovirus.
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Affiliation(s)
- E Rimstad
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - T Markussen
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
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10
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Teffer AK, Carr J, Tabata A, Schulze A, Bradbury I, Deschamps D, Gillis CA, Brunsdon EB, Mordecai G, Miller KM. A molecular assessment of infectious agents carried by Atlantic salmon at sea and in three eastern Canadian rivers, including aquaculture escapees and North American and European origin wild stocks. Facets (Ott) 2020. [DOI: 10.1139/facets-2019-0048] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Infectious agents are key components of animal ecology and drivers of host population dynamics. Knowledge of their diversity and transmission in the wild is necessary for the management and conservation of host species like Atlantic salmon ( Salmo salar). Although pathogen exchange can occur throughout the salmon life cycle, evidence is lacking to support transmission during population mixing at sea or between farmed and wild salmon due to aquaculture exposure. We tested these hypotheses using a molecular approach that identified infectious agents and transmission potential among sub-adult Atlantic salmon at marine feeding areas and adults in three eastern Canadian rivers with varying aquaculture influence. We used high-throughput qPCR to quantify infection profiles and next generation sequencing to measure genomic variation among viral isolates. We identified 14 agents, including five not yet described as occurring in Eastern Canada. Phylogenetic analysis of piscine orthoreovirus showed homology between isolates from European and North American origin fish at sea, supporting the hypothesis of intercontinental transmission. We found no evidence to support aquaculture influence on wild adult infections, which varied relative to environmental conditions, life stage, and host origin. Our findings identify research opportunities regarding pathogen transmission and biological significance for wild Atlantic salmon populations.
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Affiliation(s)
- Amy K. Teffer
- Department of Forest and Conservation Sciences, University of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada
| | - Jonathan Carr
- Atlantic Salmon Federation, Chamcook, NB E5B 3A9, Canada
| | - Amy Tabata
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7, Canada
| | - Angela Schulze
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7, Canada
| | - Ian Bradbury
- Salmonids Section, Fisheries and Oceans Canada, St. John’s, NF A1C 5X1, Canada
| | - Denise Deschamps
- Ministère des Forêts, de la Faune et des Parcs du Québec, Direction de l’expertise sur la faune aquatique, Quebec, QC G1S 4X4, Canada
| | | | | | - Gideon Mordecai
- Department of Medicine, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
| | - Kristina M. Miller
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7, Canada
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Madhun AS, Mæhle S, Wennevik V, Karlsbakk E. Prevalence and genotypes of infectious salmon anaemia virus (ISAV) in returning wild Atlantic salmon (Salmo salar L.) in northern Norway. JOURNAL OF FISH DISEASES 2019; 42:1217-1221. [PMID: 31192460 PMCID: PMC6851747 DOI: 10.1111/jfd.13021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/12/2019] [Accepted: 04/14/2019] [Indexed: 06/09/2023]
Affiliation(s)
| | - Stig Mæhle
- Institute of Marine ResearchBergenNorway
| | | | - Egil Karlsbakk
- Institute of Marine ResearchBergenNorway
- Department of Biological SciencesUniversity of BergenBergenNorway
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Nylund A, Brattespe J, Plarre H, Kambestad M, Karlsen M. Wild and farmed salmon (Salmo salar) as reservoirs for infectious salmon anaemia virus, and the importance of horizontal- and vertical transmission. PLoS One 2019; 14:e0215478. [PMID: 30990853 PMCID: PMC6467415 DOI: 10.1371/journal.pone.0215478] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/02/2019] [Indexed: 11/19/2022] Open
Abstract
The infectious salmon anaemia virus (ISAV) is an important pathogen on farmed salmon in Europe. The virus occurs as low- and high virulent variants where the former seem to be a continuous source of new high virulent ISAV. The latter are controlled in Norway by stamping out infected populations while the former are spreading uncontrolled among farmed salmon. Evidence of vertical transmission has been presented, but there is still an ongoing discussion of the importance of circulation of ISAV via salmon brood fish. The only known wild reservoirs are in trout (Salmo trutta) and salmon (Salmo salar). This study provides the first ISAV sequences from wild salmonids in Norway and evaluates the importance of this reservoir with respect to outbreaks of ISA among farmed salmon. Phylogenetic analyses of the surface protein hemagglutinin-esterase gene from nearly all available ISAV from Norway, Faeroe Islands, Scotland, Chile and wild salmonids in Norway show that they group into four major clades. Including virulent variants in the analysis show that they belong in the same four clades supporting the hypothesis that there is a high frequency of transition from low to high virulent variants in farmed populations of salmon. There is little support for a hypothesis suggesting that the wild salmonids feed the virus into farmed populations. This study give support to earlier studies that have documented local horizontal transmission of high virulent ISAV, but the importance of transition from low- to high virulent variants has been underestimated. Evidence of vertical transmission and long distance spreading of ISAV via movement of embryos and smolt is presented. We recommend that the industry focus on removing the low virulent ISAV from the brood fish and that ISAV-free brood fish salmon are kept in closed containment systems (CCS).
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Affiliation(s)
- Are Nylund
- University of Bergen, Fish Diseases Research Group, Bergen, Norway
- * E-mail:
| | - Jarle Brattespe
- University of Bergen, Fish Diseases Research Group, Bergen, Norway
| | - Heidrun Plarre
- University of Bergen, Fish Diseases Research Group, Bergen, Norway
| | - Martha Kambestad
- University of Bergen, Fish Diseases Research Group, Bergen, Norway
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Arseneau JR, Gautreau C, Boston L, Goguen ML, Laflamme M. Accelerated ISAV replication detection by cell culture methods combined with time-monitoring RT-qPCR. JOURNAL OF FISH DISEASES 2019; 42:257-267. [PMID: 30488967 DOI: 10.1111/jfd.12925] [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: 08/13/2018] [Revised: 10/19/2018] [Accepted: 10/22/2018] [Indexed: 06/09/2023]
Abstract
Infectious salmon anaemia (ISA) is a viral disease that affects farmed Atlantic salmon (Salmo salar L.), often leading to mass mortalities. A quick detection of the ISA virus (ISAV) is crucial for decision-making and can prevent the occurrence of future outbreaks. Screening done by Canada's National Aquatic Animal Health Laboratory System (NAAHLS) uses quantitative reverse transcription PCR (RT-qPCR) followed by sequencing of PCR amplicons. As neither technique provides information regarding the infectivity of the virus, suspected virulent strains are subsequently tested using viral isolation. However, this stepwise process can require significant time to deliver results. To speed up this delivery, we have improved on these pre-existing techniques by combining the use of cell culture with RT-qPCR to detect replicative virus in as little as 5 days. Preliminary assays enabled the establishment of a minimal shift in Ct values over time, which is representative of viral replication in cultured cells. Subsequent blind panel analyses allowed the establishment of the optimal sampling days, as well as diagnostic sensitivity (DSe) and specificity (DSp) estimates. This method could be adopted not only by laboratories conducting diagnostic analyses for ISAV, but also for other slow-replicating viral agents that replicate through a budding mechanism.
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Affiliation(s)
- Jean-René Arseneau
- Fisheries and Oceans Canada, Gulf Fisheries Centre, Moncton, New Brunswick, Canada
| | - Chantal Gautreau
- Fisheries and Oceans Canada, Gulf Fisheries Centre, Moncton, New Brunswick, Canada
| | - Linda Boston
- Fisheries and Oceans Canada, Gulf Fisheries Centre, Moncton, New Brunswick, Canada
| | - Michel L Goguen
- Fisheries and Oceans Canada, Gulf Fisheries Centre, Moncton, New Brunswick, Canada
| | - Mark Laflamme
- Fisheries and Oceans Canada, Gulf Fisheries Centre, Moncton, New Brunswick, Canada
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LeBlanc F, Leadbeater S, Laflamme M, Gagné N. In vivo virulence and genomic comparison of infectious Salmon Anaemia Virus isolates from Atlantic Canada. JOURNAL OF FISH DISEASES 2018; 41:1373-1384. [PMID: 29938793 DOI: 10.1111/jfd.12832] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 05/04/2018] [Accepted: 05/07/2018] [Indexed: 06/08/2023]
Abstract
The infectious salmon anaemia virus (ISAV) is capable of causing a significant disease in Atlantic salmon, which has resulted in considerable financial losses for salmon farmers around the world. Since the first detection of ISAV in Canada in 1996, it has been a high priority for aquatic animal health management and surveillance programmes have led to the identification of many genetically distinct ISAV isolates of variable virulence. In this study, we evaluated the virulence of three ISAV isolates detected in Atlantic Canada in 2012 by doing in vivo-controlled disease challenges with two sources of Atlantic salmon. We measured viral loads in fish tissues during the course of infection. Sequences of the full viral RNA genomes of these three ISAV isolates were obtained and compared to a high-virulence and previously characterized isolate detected in the Bay of Fundy in 2004, as well as a newly identified ISAV NA-HPR0 isolate. All three ISAV isolates studied were shown to be of low to mid-virulence with fish from source A having a lower mortality rate than fish from source B. Viral load estimation using an RT-qPCR assay targeting viral segment 8 showed a high degree of similarity between tissues. Through genomic comparison, we identified various amino acid substitutions unique to some isolates, including a stop codon in the segment 8 ORF2 not previously reported in ISAV, present in the isolate with the lowest observed virulence.
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Affiliation(s)
- Francis LeBlanc
- Fisheries & Oceans Canada, Gulf Fisheries Center, Moncton, NB, Canada
| | - Steven Leadbeater
- Fisheries & Oceans Canada, St Andrews Biological Station, St Andrews, NB, Canada
| | - Mark Laflamme
- Fisheries & Oceans Canada, Gulf Fisheries Center, Moncton, NB, Canada
| | - Nellie Gagné
- Fisheries & Oceans Canada, Gulf Fisheries Center, Moncton, NB, Canada
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