Viral diseases pose a significant threat to the productivity in aquaculture. Heart- and skeletal muscle inflammation (HSMI) is an emerging disease Atlantic salmon (Salmo salar) farming. HSMI associated with Piscine orthoreovirus (PRV) infection, but PRV ubiquitous farmed thus present also apparently healthy individuals. This has brought speculations if additional etiological factors are required, experiments focusing on causal relationship between highly warranted. A major bottleneck...

Environmental DNA (eDNA) monitoring is growing increasingly popular in aquatic systems as a valuable complementary method to conventional monitoring. However, such tools have not yet been extensively applied for metazoan fish parasite The ectoparasite Gyrodactylus salaris, introduced into Norway 1975, has caused severe damage Atlantic salmon populations and fisheries. Successful eradication of the carried out several river Norway, remain infected only seven rivers, including three Drammen...

Piscine orthoreovirus (PRV) is associated with heart- and skeletal muscle inflammation (HSMI) of farmed Atlantic salmon (Salmo salar). We have performed detailed sequence analysis the PRV genome focus on putative encoded proteins, compared prototype strains from mammalian (MRV T3D)- avian orthoreoviruses (ARV-138), aquareovirus (GCRV-873). Amino acid identities were low for most gene segments but showed that many protein motifs or key amino residues known to be central function are conserved...

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 rainbow trout (Oncorhynchus mykiss) with HSMI-like disease. is considered to be an emerging pathogen salmonids. In this study, molecular antigenic characterization of PRV-3 performed. Erythrocytes are the main target cells for PRV, blood samples that were collected from experimentally challenged fish...

Piscine orthoreovirus 1 (PRV-1) is the causative agent of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar). The virus widespread was present Norway long before first description HSMI 1999. Furthermore, Canada prevalent but not Canadian isolates have failed to reproduce experimentally. This has led hypothesis that there are virulence differences between PRV-1 isolates. In this study we performed a dose standardized challenge trial, comparing six isolates,...

Infectious Salmon Anaemia (ISA) is a disease affecting farmed Atlantic salmon, and most salmon producing countries have experienced ISA outbreaks. The aim of the present study was to use epidemiological viral sequence information trace transmission pathways for virus (ISAV) in Norwegian farming. covers period from January 2007 July 2009 with relatively high rate outbreaks, including large cluster outbreaks that emerged Northern Norway (the North-cluster). Farms neighbouring farms...

Piscine orthoreovirus (PRV) is ubiquitous in farmed Atlantic salmon (Salmo salar) and the cause of heart skeletal muscle inflammation. Erythrocytes are important target cells for PRV. We have investigated kinetics PRV infection blood cells. The findings indicate that causes an acute lasting 1–2 weeks, before it subsides into persistence. A high production viral proteins occurred initially phase which significantly correlated with antiviral gene transcription. Globular factories organized by...

Heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar) was first diagnosed Norway 1999. The disease is caused by Piscine orthoreovirus-1 (PRV-1). virus prevalent salmon, but not always associated with disease. Phylogeny sequence analyses of 31 PRV-1 genomes collected over a 30-year period from fish or without HSMI, grouped the viral sequences into two main monophylogenetic clusters, one HSMI other low virulent isolates. A strain sampled 1988, decade before...

Piscine orthoreovirus (PRV) is associated with heart- and skeletal muscle inflammation in farmed Atlantic salmon. The virus ubiquitous found both wild salmonid fish. It belongs to the family Reoviridae, closely related genus Orthoreovirus. PRV genome comprises ten double-stranded RNA segments encoding at least eight structural two non-structural proteins. Erythrocytes are major target cells for PRV. Infected erythrocytes contain globular inclusions resembling viral factories; putative site...

To close the gap between ultra-hygienic research mouse models and much more environmentally exposed conditions of humans, we have established a system where laboratory mice are raised under full set environmental factors present in naturalistic, farmyard-type habitat-a process called feralization. In previous studies shown that feralized (Fer) were protected against colorectal cancer when compared to conventionally reared (Lab). However, protective mechanisms remain be elucidated. Disruption...

Abstract The salmonid orthomyxovirus infectious salmon anaemia virus ( ISAV ) causes disease of varying severity in farmed A tlantic salmon, S almo salar L . Field observations suggest that host factors, the environment and differences between strains attribute to large variation progression. Variation mortality dissemination isolates with high low virulence (based on a previously published injection challenge) were investigated using immersion challenge. Virus was determined real‐time PCR...

Over a decade since its discovery, piscine myocarditis virus (PMCV) remains significant pathogen in Atlantic salmon aquaculture. Despite this impact, the genomic landscape, evolutionary dynamics, and virulence factors of PMCV are poorly understood. This study enhances existing sequence dataset by adding 34 genome sequences 202 new ORF3 from clinical cardiomyopathy syndrome (CMS) cases Norwegian Phylogenetic analyses, also including Faroe Islands Ireland revealed that highly conserved with...

Uncultivable HPR0 strains of infectious salmon anaemia viruses (ISAVs) infecting gills are non-virulent putative precursors virulent ISAVs (vISAVs) causing systemic disease in farmed Atlantic (Salmo salar). The transition to virulence involves two molecular events, a deletion the highly polymorphic region (HPR) hemagglutinin-esterase (HE) gene and Q266→L266 substitution or insertion next cleavage site (R267) fusion protein (F). We have performed ultra-deep pyrosequencing (UDPS) these regions...

Piscine orthoreovirus (PRV) is associated with heart-and skeletal muscle inflammation (HSMI) of farmed Atlantic salmon (Salmo salar).We have performed detailed sequence analysis the PRV genome focus on putative encoded proteins, compared prototype strains from mammalian (MRV T3D)-and avian orthoreoviruses (ARV-138), and aquareovirus (GCRV-873).Amino acid identities were low for most gene segments but showed that many protein motifs or key amino residues known to be central function are...

In Infectious salmon anaemia virus (ISAV), deletions in the highly polymorphic region (HPR) near membrane domain of haemagglutinin-esterase (HE) stalk, influence viral fusion. It is suspected that selected mutations associated Fusion (F) protein may also be important regulating fusion activity. To better understand underlying mechanisms involved ISAV fusion, several mutated F proteins were generated from Scottish Nevis and Norwegian SK779/06 HPR0. Co-transfection with constructs encoding HE...

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, regeneration has not been thoroughly described. In this study, cellular localization variation PRV-1 RNA protein levels were analyzed at different times post-exposure experimentally infected salmon. Immunohistochemistry, flow cytometry, Western blot used for assessment presence σ1 protein, while RT-qPCR situ...

Salmonid alphavirus (SAV) is the cause of pancreas disease and sleeping in farmed salmonid fish Europe. The spread these diseases has been difficult to control with biosecurity current vaccination strategies, increased understanding viral pathogenesis could be beneficial for development novel vaccine strategies. N-glycosylation envelope proteins may crucial virulence a possible target its purposed attenuation. In this study, we mutated consensus motifs E1 E2 glycoproteins SAV3 infectious...

Observations from the field and experimental evidence suggest that different strains of infectious salmon anaemia virus (ISAV) can induce disease varying severity in Atlantic salmon. Variation host mortality dissemination ISAV isolates with high low virulence was investigated using immersion challenge; which mortality, pathological, immunohistochemical preliminary molecular results have been previously published. Here, real-time RT-PCR analysis statistical modelling used to further...

Infectious pancreatic necrosis virus (IPNV) is a common pathogen of rainbow trout (Oncorhynchus mykiss) in Turkey. We found that 455 1,676 sample pools tested were IPNV positive. Positive samples all geographical regions where sampling was conducted. Sequence and phylogenetic analyses VP2 from 30 isolates representing showed the viruses highly similar sequence grouped within Genogroup 5 (serotype Sp-A2). No correlations between sequences, sites or origins identified. Although clinical...