scholarly journals Assessment of Marine Gill Disease in Farmed Atlantic Salmon (Salmo salar) in Chile Using a Novel Total Gross Gill Scoring System: A Case Study

2021 ◽  
Vol 9 (12) ◽  
pp. 2605
Author(s):  
Sophie Fridman ◽  
Smaragda Tsairidou ◽  
Nilantha Jayasuriya ◽  
Halina Sobolewska ◽  
Alastair Hamilton ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Scoring System ◽  
Mitigation Strategies ◽  
System A ◽  
Control And Prevention ◽  
Gill Disease ◽  
Effective Diagnosis ◽  
Farmed Atlantic Salmon ◽  
Finfish Aquaculture

Gill disorders have become more prevalent and widespread in finfish aquaculture in recent years. Their aetiology is often considered to be multifactorial. Effective diagnosis, control and prevention are hindered by the lack of standardised methodologies to characterise the aetiological agents, which produce an array of clinical and pathological presentations. The aim of this study was to define a novel gross pathological scoring system suitable for field-based macroscopic assessment of complex or multifactorial gill disease in farmed Atlantic salmon, using samples derived from a gill disease outbreak in Chile. Clinical assessment of gross gill morphology was performed, and gill samples were collected for qPCR and histology. A novel total gill scoring system was developed, which assesses gross pathological changes combining both the presumptive or healed amoebic gill disease (AGD) and the presence of other types of gill lesions. This scoring system offers a standardised approach to characterise the severe proliferative pathologies in affected gills. This total gill scoring system can substantially contribute to the development of robust mitigation strategies and could be used as an indicator trait for incorporating resistance to multifactorial gill disease into breeding goals.

Temporal changes in infections with some pathogens associated with gill disease in farmed Atlantic salmon ( Salmo salar L)

Aquaculture ◽  
2017 ◽  
Vol 468 ◽  
pp. 126-134 ◽  
Author(s):  
G.S Gunnarsson ◽  
E Karlsbakk ◽  
S Blindheim ◽  
H Plarre ◽  
A.K Imsland ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Temporal Changes ◽  
Atlantic Salmon Salmo Salar ◽  
Gill Disease ◽  
Farmed Atlantic Salmon

scholarly journals Dynamic Gill and Mucous Microbiomes Track an Amoebic Gill Disease Episode in Farmed Atlantic Salmon

2020 ◽  
Author(s):  
Victor Blasco Birlanga ◽  
Grace McCormack ◽  
Umer Zeeshan Ijaz ◽  
Eugene McCarthy ◽  
Cindy Smith ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Rrna Genes ◽  
Prokaryotic Community ◽  
Sampling Campaign ◽  
Healthy State ◽  
Disease Episode ◽  
Gill Disease ◽  
Farmed Atlantic Salmon ◽  
18S Rrna Genes ◽  
Pcr Targeting

Abstract Background Amongst gill disorders in Atlantic salmon, amoebic gill disease (AGD) is currently one of the most common and virulent, resulting in large losses for the aquaculture industry. However, our understanding of the role of the gill microbiome during AGD development is limited. Thus, we undertook a longitudinal study with the main objective of characterising the microbiome of gill, and mucous, samples from farmed Atlantic salmon before, and during, an AGD episode. Using a newly optimised DNA extraction protocol, we sequenced rRNA genes from 90 Atlantic salmon gill microbiomes from a fish farm (West coast of Ireland) over the course of a summer season. The first aetiological agent of AGD, Neoparamoeba perurans , was quantified using PCR targeting 18S rRNA genes. The same analyses were done using mucous samples as suitable, non-lethal alternatives to gill samples. Microbiome features across the sampling campaign were distinguished, focusing on patterns before and during the AGD episode. Results The richness and balance of the prokaryotic community on gills were trending upwards prior to the first appearance of AGD symptoms. The microbiome changed significantly, with reduced diversity and balance, after the AGD episode was confirmed, and the changing bacterial community was driven by competitive exclusion. However, this trend was reversed with the application of a first, and a second, freshwater bath treatment. Mucous samples behaved similarly. The variance of the entire prokaryotic community from both gill and mucous samples was significantly affected by the abundance of N. perurans . Rubritalea sp. were abundant in every gill and mucous sample; however, other genera ( Dyadobacter, Shewanella and Pedobacter ) were maximally abundant in gill and mucous samples 12 days prior to the first detection of AGD symptoms. Conclusions Gill and mucous microbiomes changed significantly after the first AGD symptoms were evident, correlating with N. perurans concentrations and supporting a connection between the development of the AGD and the gill microbiome. Those changes, however, were reversed by the application of multiple freshwater treatments, which returned gills to a more healthy state. Despite differences between microbiome features from gill and mucous samples, the data establish mucous scrapings as suitable, non-lethal substitutes for partial characterisation of the whole prokaryotic community from fish gills. The genus Shewanella was widely present, and significantly more abundant, immediately before the first AGD symptoms than during the AGD episode, marking this out as a feasible, putative target in identifying proxies for early detection of AGD.

Local and systemic humoral immune response in farmed Atlantic salmon ( Salmo salar L.) under a natural amoebic gill disease outbreak

2017 ◽  
Vol 66 ◽  
pp. 207-216 ◽  
Author(s):  
Mar Marcos-López ◽  
Cristóbal Espinosa Ruiz ◽  
Hamish D. Rodger ◽  
Ian O'Connor ◽  
Eugene MacCarthy ◽  
...  
Keyword(s):  
Immune Response ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Humoral Immune Response ◽  
Disease Outbreak ◽  
Humoral Immune ◽  
Atlantic Salmon Salmo Salar ◽  
Gill Disease ◽  
Farmed Atlantic Salmon

scholarly journals A diversity of amoebae colonise the gills of farmed Atlantic salmon (Salmo salar) with amoebic gill disease (AGD)

2019 ◽  
Vol 67 ◽  
pp. 27-45 ◽  
Author(s):  
Chloe J. English ◽  
Tomáš Tyml ◽  
Natasha A. Botwright ◽  
Andrew C. Barnes ◽  
James W. Wynne ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar ◽  
Gill Disease ◽  
Farmed Atlantic Salmon

Gill disease in marine farmed Atlantic salmon at four farms in Ireland

2011 ◽  
Vol 168 (25) ◽  
pp. 668-668 ◽  
Author(s):  
H. D. Rodger ◽  
K. Murphy ◽  
S. O. Mitchell ◽  
L. Henry
Keyword(s):  
Atlantic Salmon ◽  
Gill Disease ◽  
Farmed Atlantic Salmon

scholarly journals No Evidence of the Vertical Transmission of Non-Virulent Infectious Salmon Anaemia Virus (ISAV-HPR0) in Farmed Atlantic Salmon

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2428
Author(s):  
Debes Hammershaimb Christiansen ◽  
Petra Elisabeth Petersen ◽  
Maria Marjunardóttir Dahl ◽  
Nicolina Vest ◽  
Maria Aamelfot ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Vertical Transmission ◽  
Mitigation Strategies ◽  
Infectious Salmon Anaemia Virus ◽  
Faroe Islands ◽  
Infection Pattern ◽  
Production Stages ◽  
Air Intake ◽  
Farmed Atlantic Salmon ◽  
Infectious Salmon Anaemia

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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