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Ghanei-Motlagh R, Hernández-Orts JS, Fast MD, Whyte SK, El-Matbouli M, Saleh M. Morphological and molecular characterization of Stomachicola muraenesocis Yamaguti, 1934 (Digenea: Hemiuridae) from the daggertooth pike conger Muraenesox cinereus (Forsskål). Parasitology 2024; 151:24-44. [PMID: 37953070 PMCID: PMC10941220 DOI: 10.1017/s0031182023001063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 10/30/2023] [Accepted: 11/01/2023] [Indexed: 11/14/2023]
Abstract
Hemiurid digeneans conspecific with Stomachicola muraenesocis Yamaguti, 1934 (the type species of the genus Stomachicola Yamaguti, 1934) were collected from the stomach of the daggertooth pike conger Muraenesox cinereus (Forsskål) off the Persian Gulf of Iran. This study aimed to provide a detailed characterization of Stom. muraenesocis, including measurements, illustrations and scanning electron microscopy (s.e.m.) representations. Comparisons with the original and previous descriptions revealed morphological and metrical variations in several features (i.e. body size and shape, arrangement of reproductive organs, soma to ecsoma length ratio, position of genital opening, number of vitelline tubules and extension of uterine coils) between Stom. muraenesocis from different hosts and localities. This study presents the first molecular sequence data associated with the small (18S) and large (28S) subunit nuclear ribosomal RNA genes (rDNA) for Stom. muraenesocis. Phylogenetic analyses of the 18S dataset placed Stom. muraenesocis as sister lineage to a clade formed of a group of species of Lecithaster Lühe, 1901 (Lecithasteridae Odhner, 1905). In contrast, phylogenetic analyses based on the 28S consistently recovered a sister relationship between Stom. muraenesocis and representatives of the Hemiuridae Looss, 1899. Further comprehensive phylogenetically based classification in light of morphology and taxonomic history of the Hemiuridae and Lecithasteridae is required to infer phylogenetic affinities and historical biogeography of Stomachicola. A comprehensive list of previously reported species of Stomachicola together with their associated hosts, localities and morphometric data is provided.
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Affiliation(s)
- Reza Ghanei-Motlagh
- Division of Fish Health, University of Veterinary Medicine, Vienna, Austria
- Hoplite Research Lab, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
| | - Jesús S. Hernández-Orts
- Natural History Museum, London, UK
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Mark D. Fast
- Hoplite Research Lab, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
| | - Shona K. Whyte
- Hoplite Research Lab, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
| | | | - Mona Saleh
- Division of Fish Health, University of Veterinary Medicine, Vienna, Austria
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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 Shellfish Immunol Rep 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Zhong L, Carvalho LA, Gao S, Whyte SK, Purcell SL, Fast MD, Cai W. Transcriptome analysis revealed immune responses in the kidney of Atlantic salmon (Salmo salar) co-infected with sea lice (Lepeophtheirus salmonis) and infectious salmon anemia virus. Fish Shellfish Immunol 2023; 143:109210. [PMID: 37951318 DOI: 10.1016/j.fsi.2023.109210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 10/17/2023] [Accepted: 11/02/2023] [Indexed: 11/13/2023]
Abstract
Sea lice (Lepeophtheirus salmonis) and infectious salmon anemia virus (ISAv) are two of the most important pathogens in Atlantic salmon (Salmo salar) farming and typically cause substantial economic losses to the industry. However, the immune interactions between hosts and these pathogens are still unclear, especially in the scenario of co-infection. In this study, we artificially infected Atlantic salmon with sea lice and ISAv, and investigated the gene expression patterns of Atlantic salmon head kidneys in response to both lice only and co-infection with lice and ISAv by transcriptomic analysis. The challenge experiment indicated that co-infection resulted in a cumulative mortality rate of 47.8 %, while no mortality was observed in the lice alone infection. We identified 240 differentially expressed genes (DEGs) under the lice alone infection, of which 185 were down-regulated and 55 were up-regulated, while a total of 994 DEGs were identified in the co-infection, of which 206 were down-regulated and 788 were significantly up-regulated. The pathway enrichment analysis revealed that single-infection significantly suppressed the innate immune system (e.g., the complement system), whereas co-infection induced a strong immune response, leading to the activation of immune-related signaling pathways such as Toll-like receptors and NOD-like receptors pathways, as well as significant upregulation of genes related to the activation of interferon and MH class I protein complex. Our results provide the first global transcriptomic study of gene expression in the Atlantic salmon head kidney in response to co-infection with sea lice and ISAv, and provided the baseline knowledge for understanding the immune responses during co-infection.
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Affiliation(s)
- Liang Zhong
- Department of Infectious Diseases and Public Health, and State Key Lab of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong
| | - Laura A Carvalho
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3, Canada
| | - Shengnan Gao
- Department of Infectious Diseases and Public Health, and State Key Lab of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong
| | - Shona K Whyte
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3, Canada
| | - Sara L Purcell
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3, Canada
| | - Mark D Fast
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3, Canada.
| | - Wenlong Cai
- Department of Infectious Diseases and Public Health, and State Key Lab of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong; Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3, Canada.
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Cai W, Kumar S, Navaneethaiyer U, Caballero-Solares A, Carvalho LA, Whyte SK, Purcell SL, Gagne N, Hori TS, Allen M, Taylor RG, Balder R, Parrish CC, Rise ML, Fast MD. Transcriptome Analysis of Atlantic Salmon ( Salmo salar) Skin in Response to Sea Lice and Infectious Salmon Anemia Virus Co-Infection Under Different Experimental Functional Diets. Front Immunol 2022; 12:787033. [PMID: 35046944 PMCID: PMC8763012 DOI: 10.3389/fimmu.2021.787033] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
Sea lice (Lepeophtheirus salmonis) are ectoparasitic copepods that cause significant economic loss in marine salmoniculture. In commercial salmon farms, infestation with sea lice can enhance susceptibility to other significant pathogens, such as the highly contagious infectious salmon anemia virus (ISAv). In this study, transcriptomic analysis was used to evaluate the impact of four experimental functional feeds (i.e. 0.3% EPA/DHA+high-ω6, 0.3% EPA/DHA+high-ω6+immunostimulant (IS), 1% EPA/DHA+high-ω6, and 1% EPA/DHA+high-ω3) on Atlantic salmon (Salmo salar) during a single infection with sea lice (L. salmonis) and a co-infection with sea lice and ISAv. The overall objectives were to compare the transcriptomic profiles of skin between lice infection alone with co-infection groups and assess differences in gene expression response among animals with different experimental diets. Atlantic salmon smolts were challenged with L. salmonis following a 28-day feeding trial. Fish were then challenged with ISAv at 18 days post-sea lice infection (dpi), and maintained on individual diets, to establish a co-infection model. Skin tissues sampled at 33 dpi were subjected to RNA-seq analysis. The co-infection’s overall survival rates were between 37%-50%, while no mortality was observed in the single infection with lice. With regard to the infection status, 756 and 1303 consensus differentially expressed genes (DEGs) among the four diets were identified in “lice infection vs. pre-infection” and “co-infection vs. pre-infection” groups, respectively, that were shared between the four experimental diets. The co-infection groups (co-infection vs. pre-infection) included up-regulated genes associated with glycolysis, the interferon pathway, complement cascade activity, and heat shock protein family, while the down-regulated genes were related to antigen presentation and processing, T-cell activation, collagen formation, and extracellular matrix. Pathway enrichment analysis conducted between infected groups (lice infection vs. co-infection) resulted in several immune-related significant GO terms and pathways unique to this group, such as “autophagosome”, “cytosolic DNA-sensing pathway” and “response to type I interferons”. Understanding how experimental functional feeds can impact the host response and the trajectory of co-infections will be an essential step in identifying efficacious intervention strategies that account for the complexities of disease in open cage culture.
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Affiliation(s)
- Wenlong Cai
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada.,Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Surendra Kumar
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | | | | | - Laura A Carvalho
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Shona K Whyte
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Sara L Purcell
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Nellie Gagne
- Fisheries and Oceans Canada, Moncton, NB, Canada
| | - Tiago S Hori
- Centre for Aquaculture Technologies Canada, Souris, PE, Canada
| | - Melissa Allen
- Centre for Aquaculture Technologies Canada, Souris, PE, Canada
| | | | - Rachel Balder
- Cargill Animal Nutrition, Elk River, MN, United States
| | - Christopher C Parrish
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Matthew L Rise
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Mark D Fast
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
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VanIderstine CR, Poley JD, Whyte SK, Purcell SL, Fast MD. Hydrogen peroxide treatment and its impacts on Lepeophtheirus salmonis originating from the Bay of Fundy, Canada. J Fish Dis 2021; 44:757-769. [PMID: 33146907 DOI: 10.1111/jfd.13299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/19/2020] [Accepted: 10/21/2020] [Indexed: 06/11/2023]
Abstract
Hydrogen peroxide (H2 O2 ) is used to treat sea lice infections of farmed salmonids in the Atlantic and Pacific Oceans and issues with resistance to this treatment, and others are a major threat to the sustainability of the industry. The objectives of this study were to determine how H2 O2 exposure affects survival and antioxidant-related gene expression in salmon lice (Lepeophtheirus salmonis) collected from the Bay of Fundy, New Brunswick. The maximum recommended dose of H2 O2 is 1,800 mg/L, while the EC50 values (with 95% CI) for the population tested were 1,486 (457, 2,515) mg/L for males and 2,126 (984, 3,268) mg/L for females. Neither temperature nor pretreatment with emamectin benzoate (EMB) impacted survival after H2 O2 exposure. RT-qPCR was performed on pre-adult sea lice exposed to H2 O2 and showed that four genes classically involved in the response to oxidative stress were unchanged between treated and control groups. Seven genes were found to be significantly upregulated in males and one in females. This is the first report on the efficacy and molecular responses of Atlantic Canada sea lice to H2 O2 treatment.
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Affiliation(s)
- Carter R VanIderstine
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Jordan D Poley
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Shona K Whyte
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Sara L Purcell
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Mark D Fast
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
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Carvalho LA, Whyte SK, Braden LM, Purcell SL, Manning AJ, Muckle A, Fast MD. Impact of co-infection with Lepeophtheirus salmonis and Moritella viscosa on inflammatory and immune responses of Atlantic salmon (Salmo salar). J Fish Dis 2020; 43:459-473. [PMID: 32100325 DOI: 10.1111/jfd.13144] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 01/16/2020] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
This study was conducted to determine the effects of a co-infection with Moritella viscosa at different exposure levels of sea lice Lepeophtheirus salmonis in Atlantic salmon (Salmo salar). M. viscosa (1.14 × 106 cfu/ml) was introduced to all experimental tanks at 10 days post-lice infection (dpLs). Mean lice counts decreased over time in both the medium lice co-infection (31.5 ± 19.0 at 7 dpLs; 16.9 ± 9.3 at 46 dpLs) and high lice co-infection (62.0 ± 10.8 at 7 dpLs; 37.6 ± 11.3 at 46 dpLs). There were significantly higher mortalities and more severe skin lesions in the high lice co-infected group compared to medium lice co-infected group or M. viscosa-only infection. Quantitative gene expression analysis detected a significant upregulation of genes in skin from the high lice co-infection group consistent with severe inflammation (il-8, mmp-9, hep, saa). Skin lesions retrieved throughout the study were positive for M. viscosa growth, but these were rarely located in regions associated with lice. These results suggest that while M. viscosa infection itself may induce skin lesion development in salmon, co-infection with high numbers of lice can enhance this impact and significantly reduce the ability of these lesions to resolve, resulting in increased mortality.
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Affiliation(s)
- Laura A Carvalho
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Shona K Whyte
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | | | - Sara L Purcell
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Anthony J Manning
- Food Fisheries and Aquaculture Department, The New Brunswick Research and Productivity Council (RPC), Fredericton, NB, Canada
| | - Anne Muckle
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Mark D Fast
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
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Braden LM, Whyte SK, Brown ABJ, Iderstine CV, Letendre C, Groman D, Lewis J, Purcell SL, Hori T, Fast MD. Vaccine-Induced Protection Against Furunculosis Involves Pre-emptive Priming of Humoral Immunity in Arctic Charr. Front Immunol 2019; 10:120. [PMID: 30778356 PMCID: PMC6369366 DOI: 10.3389/fimmu.2019.00120] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Accepted: 01/15/2019] [Indexed: 11/20/2022] Open
Abstract
With respect to salmonid aquaculture, one of the most important bacterial pathogens due to high mortality and antibiotic usage is the causative agent of typical furunculosis, Aeromonas salmonicida spp. salmonicida (Asal). In Atlantic salmon, Salmo salar, the host response during infections with Asal is well-documented, with furunculosis outbreaks resulting in significant mortality in commercial settings. However, less is known about the host-pathogen interactions in the emerging aquaculture species, Arctic charr Salvelinus alpinus. Furthermore, there is no data on the efficacy or response of this species after vaccination with commonly administered vaccines against furunculosis. To this end, we examined the immunological response of S. alpinus during infection with Asal, with or without administration of vaccines (Forte Micro®, Forte Micro® + Renogen®, Elanco Animal Health). Artic charr (vaccinated or unvaccinated) were i.p.-injected with a virulent strain of Asal (106 CFUs/mL) and tissues were collected pre-infection/post-vaccination, 8, and 29 days post-infection. Unvaccinated Arctic charr were susceptible to Asal with 72% mortalities observed after 31 days. However, there was 72–82% protection in fish vaccinated with either the single or dual-vaccine, respectively. Protection in vaccinated fish was concordant with significantly higher serum IgM concentrations, and following RNA sequencing and transcriptome assembly, differential expression analysis revealed several patterns and pathways associated with the improved survival of vaccinated fish. Most striking was the dramatically higher basal expression of complement/coagulation factors, acute phase-proteins, and iron hemostasis proteins in pre-challenged, vaccinated fish. Remarkably, following Asal infection, this response was abrogated and instead the transcriptome was characterized by a lack of immune-stimulation compared to that of unvaccinated fish. Furthermore, where pathways of actin assembly and FcγR-mediated phagocytosis were significantly differentially regulated in unvaccinated fish, vaccinated fish showed either the opposite regulation (ForteMicro®), or no impact at all (ForteMicro®Renogen®). The present data indicates that vaccine-induced protection against Asal relies on the pre-activation and immediate control of humoral immune parameters that is coincident with reduced activation of apoptotic (e.g., NF-κB) and actin-associated pathways.
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Affiliation(s)
- Laura M Braden
- Hoplite Laboratory, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Shona K Whyte
- Hoplite Laboratory, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Alyson B J Brown
- Hoplite Laboratory, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Carter Van Iderstine
- Hoplite Laboratory, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Corinne Letendre
- Department of Veterinary Sciences, Universite de Montreal, Montreal, QC, Canada
| | - David Groman
- Hoplite Laboratory, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Jeff Lewis
- Hoplite Laboratory, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Sara L Purcell
- Hoplite Laboratory, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Tiago Hori
- Centre for Aquaculture Technologies Canada, Souris, PE, Canada
| | - Mark D Fast
- Hoplite Laboratory, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
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Poley JD, Braden LM, Messmer AM, Igboeli OO, Whyte SK, Macdonald A, Rodriguez J, Gameiro M, Rufener L, Bouvier J, Wadowska DW, Koop BF, Hosking BC, Fast MD. High level efficacy of lufenuron against sea lice (Lepeophtheirus salmonis) linked to rapid impact on moulting processes. Int J Parasitol Drugs Drug Resist 2018; 8:174-188. [PMID: 29627513 PMCID: PMC6039351 DOI: 10.1016/j.ijpddr.2018.02.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 02/26/2018] [Accepted: 02/28/2018] [Indexed: 11/29/2022]
Abstract
Drug resistance in the salmon louse Lepeophtheirus salmonis is a global issue for Atlantic salmon aquaculture. Multiple resistance has been described across most available compound classes with the exception of the benzoylureas. To target this gap in effective management of L. salmonis and other species of sea lice (e.g. Caligus spp.), Elanco Animal Health is developing an in-feed treatment containing lufenuron (a benzoylurea) to be administered prior to seawater transfer of salmon smolts and to provide long-term protection of salmon against sea lice infestations. Benzoylureas disrupt chitin synthesis, formation, and deposition during all moulting events. However, the mechanism(s) of action are not yet fully understood and most research completed to date has focused on insects. We exposed the first parasitic stage of L. salmonis to 700 ppb lufenuron for three hours and observed over 90% reduction in survival to the chalimus II life stage on the host, as compared to vehicle controls. This agrees with a follow up in vivo administration study on the host, which showed >95% reduction by the chalimus I stage. Transcriptomic responses of salmon lice exposed to lufenuron included genes related to moulting, epithelial differentiation, solute transport, and general developmental processes. Global metabolite profiles also suggest that membrane stability and fluidity is impacted in treated lice. These molecular signals are likely the underpinnings of an abnormal moulting process and cuticle formation observed ultrastructurally using transmission electron microscopy. Treated nauplii-staged lice exhibited multiple abnormalities in the integument, suggesting that the coordinated assembly of the epi- and procuticle is impaired. In all cases, treatment with lufenuron had rapid impacts on L. salmonis development. We describe multiple experiments to characterize the efficacy of lufenuron on eggs, larvae, and parasitic stages of L. salmonis, and provide the most comprehensive assessment of the physiological responses of a marine arthropod to a benzoylurea chemical.
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Affiliation(s)
- Jordan D Poley
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
| | - Laura M Braden
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
| | - Amber M Messmer
- Centre for Biomedical Research, Department of Biology, University of Victoria, Victoria BC, V8W 3N5, Canada.
| | - Okechukwu O Igboeli
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
| | - Shona K Whyte
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
| | - Alicia Macdonald
- Elanco Canada Limited, 150 Research Lane, Guelph, Ontario N1G 4T2, Canada.
| | - Jose Rodriguez
- Elanco Canada Limited, 150 Research Lane, Guelph, Ontario N1G 4T2, Canada.
| | - Marta Gameiro
- Elanco Canada Limited, 150 Research Lane, Guelph, Ontario N1G 4T2, Canada.
| | - Lucien Rufener
- Elanco Centre de Recherche Santé Animale SA, CH-1566 St.-Aubin, Switzerland; INVENesis LLC, Chemin de Belleroche 14, 2000 Neuchâtel, Switzerland.
| | - Jacques Bouvier
- Elanco Centre de Recherche Santé Animale SA, CH-1566 St.-Aubin, Switzerland; INVENesis LLC, Chemin de Belleroche 14, 2000 Neuchâtel, Switzerland.
| | - Dorota W Wadowska
- Electron Microscopy Laboratory, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown, PEI, C1A 4P3, Canada.
| | - Ben F Koop
- Centre for Biomedical Research, Department of Biology, University of Victoria, Victoria BC, V8W 3N5, Canada.
| | - Barry C Hosking
- Elanco Canada Limited, 150 Research Lane, Guelph, Ontario N1G 4T2, Canada.
| | - Mark D Fast
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
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Braden LM, Rasmussen KJ, Purcell SL, Ellis L, Mahony A, Cho S, Whyte SK, Jones SRM, Fast MD. Acquired Protective Immunity in Atlantic Salmon Salmo salar against the Myxozoan Kudoa thyrsites Involves Induction of MHIIβ + CD83 + Antigen-Presenting Cells. Infect Immun 2018; 86:e00556-17. [PMID: 28993459 PMCID: PMC5736826 DOI: 10.1128/iai.00556-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/03/2017] [Indexed: 12/15/2022] Open
Abstract
The histozoic myxozoan parasite Kudoa thyrsites causes postmortem myoliquefaction and is responsible for economic losses to salmon aquaculture in the Pacific Northwest. Despite its importance, little is known about the host-parasite relationship, including the host response to infection. The present work sought to characterize the immune response in Atlantic salmon during infection, recovery, and reexposure to K. thyrsites After exposure to infective seawater, infected and uninfected smolts were sampled three times over 4,275 degree-days. Histological analysis revealed infection severity decreased over time in exposed fish, while in controls there was no evidence of infection. Following a secondary exposure of all fish, severity of infection in the controls was similar to that measured in exposed fish at the first sampling time but was significantly reduced in reexposed fish, suggesting the acquisition of protective immunity. Using immunohistochemistry, we detected a population of MHIIβ+ cells in infected muscle that followed a pattern of abundance concordant with parasite prevalence. Infiltration of these cells into infected myocytes preceded destruction of the plasmodium and dissemination of myxospores. Dual labeling indicated a majority of these cells were CD83+/MHIIβ+ Using reverse transcription-quantitative PCR, we detected significant induction of cellular effectors, including macrophage/dendritic cells (mhii/cd83/mcsf), B cells (igm/igt), and cytotoxic T cells (cd8/nkl), in the musculature of infected fish. These data support a role for cellular effectors such as antigen-presenting cells (monocyte/macrophage and dendritic cells) along with B and T cells in the acquired protective immune response of Atlantic salmon against K. thyrsites.
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Affiliation(s)
- Laura M Braden
- Hoplite Laboratory, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Karina J Rasmussen
- Department of Cancer and Inflammation Research, University of Southern Denmark, Odense, Denmark
| | - Sara L Purcell
- Hoplite Laboratory, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Lauren Ellis
- Hoplite Laboratory, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Amelia Mahony
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Steven Cho
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Shona K Whyte
- Hoplite Laboratory, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - Simon R M Jones
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Mark D Fast
- Hoplite Laboratory, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
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10
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Poley JD, Braden LM, Messmer AM, Whyte SK, Koop BF, Fast MD. Cypermethrin exposure induces metabolic and stress-related gene expression in copepodid salmon lice (Lepeophtheirus salmonis). Comp Biochem Physiol Part D Genomics Proteomics 2016; 20:74-84. [PMID: 27612154 DOI: 10.1016/j.cbd.2016.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 08/05/2016] [Accepted: 08/11/2016] [Indexed: 01/12/2023]
Abstract
Cypermethrin has been administered for decades to control salmon lice (Lepeophtheirus salmonis) infestations in Atlantic salmon farming regions globally. However, resistance to cypermethrin and other available therapeutants has threatened the sustainability of this growing industry. To better understand the effects of cypermethrin on L. salmonis, a 38K oligonucleotide microarray and RT-qPCR analyses were applied to pools of copepodid larvae exposed to 1.0ppb cypermethrin or seawater controls for 24h. Phenotypic assessments and global gene expression profiles showed a significant disruption of homeostasis in copepodid L. salmonis exposed to cypermethrin. Multiple degradative enzymes were overexpressed in cypermethrin-treated lice including five trypsin-like serine proteases and three cytochrome p450s CYP3a24 (p=0.03, fold change (FC)=3.8; GenBank accession no. JP326960.1), CYP6w1 (p=0.008, FC=5.3; GenBank accession no. JP317875.1), and CYP6d4 (p=0.01; FC=7.9; GenBank accession no. JP334550.1). These enzymes represent preliminary markers for understanding the physiological response of L. salmonis to cypermethrin exposure. A general stress response was also observed in cypermethrin-treated lice which included differential expression of cell signaling genes involved in the induction of cell growth, solute transport, and metabolism. Lastly, a consensus-based analysis was completed with two previously published L. salmonis transcriptome studies revealing genes that respond to cypermethrin, emamectin benzoate (another delousing agent) and hyposalinity. This included concordant differential expression of heat shock beta-1, ammonium transporter Rh types B, and 72kDa type IV collagenase across different L. salmonis studies. This is currently the most comprehensive transcriptome assessment of chemical exposure on the first infectious stage of L. salmonis, providing novel markers for studying drug resistance and general stress in this important parasite.
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Affiliation(s)
- Jordan D Poley
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown, PE, C1A 4P3, Canada.
| | - Laura M Braden
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown, PE, C1A 4P3, Canada.
| | - Amber M Messmer
- Centre for Biomedical Research, Department of Biology, University of Victoria, Victoria, BC, V8W 3N5, Canada.
| | - Shona K Whyte
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown, PE, C1A 4P3, Canada.
| | - Ben F Koop
- Centre for Biomedical Research, Department of Biology, University of Victoria, Victoria, BC, V8W 3N5, Canada.
| | - Mark D Fast
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown, PE, C1A 4P3, Canada.
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11
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Whyte SK, Westcott JD, Elmoslemany A, Hammell KL, Revie CW. A fixed-dose approach to conducting emamectin benzoate tolerance assessments on field-collected sea lice, Lepeophtheirus salmonis. J Fish Dis 2013; 36:283-292. [PMID: 23305353 DOI: 10.1111/jfd.12055] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 10/11/2012] [Accepted: 10/17/2012] [Indexed: 06/01/2023]
Abstract
In New Brunswick, Canada, the sea louse, Lepeophtheirus salmonis, poses an on-going management challenge to the health and productivity of commercially cultured Atlantic salmon, Salmo salar. While the in-feed medication, emamectin benzoate (SLICE® ; Merck), has been highly effective for many years, evidence of increased tolerance has been observed in the field since late 2008. Although bioassays on motile stages are a common tool to monitor sea lice sensitivity to emamectin benzoate in field-collected sea lice, they require the collection of large numbers of sea lice due to inherent natural variability in the gender and stage response to chemotherapeutants. In addition, sensitive instruments such as EC(50) analysis may be unnecessarily complex to characterize susceptibility subsequent to a significant observed decline in efficacy. This study proposes an adaptation of the traditional, dose-response format bioassay to a fixed-dose method. Analysis of 657 bioassays on preadult and adult stages of sea lice over the period 2008-2011 indicated a population of sea lice in New Brunswick with varying degrees of susceptibility to emamectin benzoate. A seasonal and spatial effect was observed in the robustness of genders and stages of sea lice, which suggest that mixing different genders and stages of lice within a single bioassay may result in pertinent information being overlooked. Poor survival of adult female lice in bioassays, particularly during May/June, indicates it may be prudent to consider excluding this stage from bioassays conducted at certain times of the year. This work demonstrates that fixed-dose bioassays can be a valuable technique in detecting reduced sensitivity in sea lice populations with varying degrees of susceptibility to emamectin benzoate treatments.
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Affiliation(s)
- S K Whyte
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada.
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12
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Elmoslemany A, Whyte SK, Revie CW, Hammell KL. Sea lice monitoring on Atlantic salmon farms in New Brunswick, Canada: comparing audit and farm staff counts. J Fish Dis 2013; 36:241-247. [PMID: 23311676 DOI: 10.1111/jfd.12051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 10/04/2012] [Accepted: 10/17/2012] [Indexed: 06/01/2023]
Abstract
Sea lice audits were performed by the Atlantic Veterinary College on commercial aquaculture sites in New Brunswick, Canada, in 2011. Although the primary objective was to verify that farms were reporting similar lice counts to third-party counts, more detailed comparisons were made to identify when lice counts were more likely to differ between the audit team and farm employees. A total of 28 sea lice audits were conducted on 16 sites between June and December 2011. During each audit, 10 cages were evaluated per site where possible, with ten fish per cage being evaluated by an audit technician and a further ten by a farm employee. Data analysis included descriptive statistics of lice counts by stage and limits of agreement plots. A random effects negative binomial model that accounted for clustering of cages within sites was applied to assess the effect of counter type and season on lice counts by stage. The results indicate that farms counts were generally in agreement with audit counts. However, when the average counts for chalimus and preadult (male and female) and adult male lice stages were high, farm counters were more likely to report a lower value. Higher lice counts were observed during autumn compared to summer especially for the adult female stage. Finally, there was a significant clustering effect for site and cage, with most of the variation attributable to site.
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Affiliation(s)
- A Elmoslemany
- Centre for Veterinary Epidemiological Research, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada.
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13
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Whyte SK. The innate immune response of finfish--a review of current knowledge. Fish Shellfish Immunol 2007; 23:1127-1151. [PMID: 17980622 DOI: 10.1016/j.fsi.2007.06.005] [Citation(s) in RCA: 327] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Revised: 05/30/2007] [Accepted: 06/01/2007] [Indexed: 05/25/2023]
Abstract
The decline in the fisheries of traditional marine species has been an incentive for the diversification of today's aquaculture sector into the intensive rearing of many finfish species. The increasing interest in commercial farming of different finfish species is expected to result in similar environmental and husbandry-related problems as have been experienced in the development of the salmonid farming industry. An understanding of the biology of the fish species being cultured, in particular the immune response is important for improved husbandry and health management of the species. The innate immune system of fish has generated increasing interest in recent years and is now thought to be of key importance in primary defence and in driving adaptive immunity. This review focuses on key components (cellular and humoral) of the innate immune responses of different fish species of commercial importance.
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Affiliation(s)
- Shona K Whyte
- Centre for Aquatic Health Sciences, Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE, C1A 4P3, Canada.
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14
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Kibenge FS, Whyte SK, Hammell KL, Rainnie D, Kibenge MT, Martin CK. A dual infection of infectious salmon anaemia (ISA) virus and a togavirus-like virus in ISA of Atlantic salmon Salmo salar in New Brunswick, Canada. Dis Aquat Organ 2000; 42:11-15. [PMID: 10986640 DOI: 10.3354/dao042011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Two viruses, infectious salmon anaemia (ISA) virus and a novel togavirus-like virus, were isolated from ISA disease outbreaks that were first reported as a new syndrome, haemorrhagic kidney syndrome (HKS) affecting farmed Atlantic salmon Salmo salar L. on the East coast of Canada. Laboratory confirmation of ISA diagnosis was initially complicated by isolation of only the togavirus-like agent using the CHSE-214 cell line. Here we demonstrate that a clinical sample from a disease outbreak of ISA contained a mixture of ISA virus and togavirus-like virus. Reverse transcriptase-polymerase chain reaction (RT-PCR) confirmed the presence of both viruses during serial passage of cultures in SHK-1 and CHSE-214 cells. Virus harvested at passage level 3 in both cell lines caused high mortalities and severe gross pathology consistent with ISA virus infection in experimentally inoculated Atlantic salmon parr (approximately 35 g) in freshwater, beginning 12 d post inoculation. ISA virus was detected by virus isolation from kidney and liver tissues of all dead or moribund fish tested. A comparison of virus isolation, 1-step procedure RT-PCR and RNA dot-blot hybridization for detection of ISA virus (ISAV) in fish tissues showed virus isolation to have 100% sensitivity, followed by RT-PCR (66 and 28% sensitivity in kidney and liver, respectively), with RNA dot-blot hybridization as the least sensitive method (20 and 10% sensitivity in kidney and liver, respectively). No togavirus-like virus was detected in these samples by virus isolation. Moreover, another togavirus-like virus isolate grown in CHSE-214 cells in the absence of any other detectable pathogen was non-pathogenic in experimentally inoculated fish. This study confirms that the original ISA outbreaks in New Brunswick, Canada, were caused solely by ISAV.
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Affiliation(s)
- F S Kibenge
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Canada.
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15
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Ortenburger AI, Jansen ME, Whyte SK. Nonsurgical videolaparoscopy for determination of reproductive status of the Arctic charr. Can Vet J 1996; 37:96-100. [PMID: 8640656 PMCID: PMC1576613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The efficient commercial production of Arctic charr is hampered by the limited and subtle sexual dimorphism shown by this species. This project examined the feasibility of low-cost videoendoscopy through the genital pore to determine sex, stage of maturity, and safety for 80, randomly selected, anesthetized Arctic charr. The sensitivity and specificity for correct assignment of male sex were 90% and 100%, respectively, among 3 observers in a single-blind design. Sensitivity and specificity for relative sexual maturity in the same fish were 96% and 54%, respectively. The observed mortality rate of 7% at the end of 3 weeks was confounded by the presence of unrelated disease. We conclude that the technique holds promise for application by producers to improve production efficiency.
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Affiliation(s)
- A I Ortenburger
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown
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16
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Abstract
The infectivity of Diplostomum spathaceum (Digenea: Trematoda) cercariae to rainbow trout and the efficacy of the diplostomule migration to the lens following different routes of administration was examined. The optimum age of infectivity for cercariae was between 0-5 h after liberation from the snail and for intraperitoneally injected diplostomules, 5 h post-transformation in vitro through fish skin. After exposure of the entire fish body or head to cercariae, metacercariae first appeared in the lens at 5 h and their numbers gradually increased until 22 h. Following exposure of the tail region of rainbow trout to cercariae, metacercariae first appeared in the lens at 14 h. Significantly more metacercariae established in the lens of fish following exposure of the fish head compared with the tail region; 40% of penetrating cercariae reached the lens of fish following exposure of the head or entire body, 20% of cercariae or diplostomules injected either intraperitoneally, intramuscularly or intracardially reached the lens while only 5% of cercariae established as metacercariae following exposure of the tail region.
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Affiliation(s)
- S K Whyte
- Department of Zoology, University of Aberdeen, UK
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