1
|
Godoy M, Montes de Oca M, Suarez R, Martinez A, Pontigo JP, Caro D, Kusch K, Coca Y, Bohle H, Bayliss S, Kibenge M, Kibenge F. Genomics of Re-Emergent Aeromonas salmonicida in Atlantic Salmon Outbreaks. Microorganisms 2023; 12:64. [PMID: 38257891 PMCID: PMC10819690 DOI: 10.3390/microorganisms12010064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 12/22/2023] [Accepted: 12/27/2023] [Indexed: 01/24/2024] Open
Abstract
Furunculosis, caused by Aeromonas salmonicida, poses a significant threat to both salmonid and non-salmonid fish in diverse aquatic environments. This study explores the genomic intricacies of re-emergent A. salmonicida outbreaks in Atlantic salmon (Salmo salar). Previous clinical cases have exhibited pathological characteristics, such as periorbital hemorrhages and gastrointestinal abnormalities. Genomic sequencing of three Chilean isolates (ASA04, ASA05, and CIBA_5017) and 25 previously described genomes determined the pan-genome, phylogenomics, insertion sequences, and restriction-modification systems. Unique gene families have contributed to an improved understanding of the psychrophilic and mesophilic clades, while phylogenomic analysis has been used to identify mesophilic and psychrophilic strains, thereby further differentiating between typical and atypical psychrophilic isolates. Diverse insertion sequences and restriction-modification patterns have highlighted genomic structural differences, and virulence factor predictions can emphasize exotoxin disparities, especially between psychrophilic and mesophilic strains. Thus, a novel plasmid was characterized which emphasized the role of plasmids in virulence and antibiotic resistance. The analysis of antibiotic resistance factors revealed resistance against various drug classes in Chilean strains. Overall, this study elucidates the genomic dynamics of re-emergent A. salmonicida and provides novel insights into their virulence, antibiotic resistance, and population structure.
Collapse
Affiliation(s)
- Marcos Godoy
- Centro de Investigaciones Biológicas Aplicadas (CIBA), Puerto Montt 5501842, Chile; (M.M.d.O.); (D.C.); (K.K.)
- Laboratorio de Biotecnología Aplicada, Facultad de Ciencias de la Naturaleza, Escuela de Medicina Veterinaria, Universidad San Sebastián, Sede de la Patagonia, Puerto Montt 5480000, Chile
| | - Marco Montes de Oca
- Centro de Investigaciones Biológicas Aplicadas (CIBA), Puerto Montt 5501842, Chile; (M.M.d.O.); (D.C.); (K.K.)
| | - Rudy Suarez
- Programa de Magíster en Acuicultura, Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo 1780000, Chile;
| | - Alexis Martinez
- ATC Patagonia S/N, Carretera Austral, Puerto Montt 5480000, Chile;
| | - Juan Pablo Pontigo
- Laboratorio Institucional, Facultad de Ciencias de la Naturaleza, Medicina Veterinaria, Universidad San Sebastián, Lago Panguipulli 1390, Puerto Montt 5501842, Chile;
| | - Diego Caro
- Centro de Investigaciones Biológicas Aplicadas (CIBA), Puerto Montt 5501842, Chile; (M.M.d.O.); (D.C.); (K.K.)
| | - Karina Kusch
- Centro de Investigaciones Biológicas Aplicadas (CIBA), Puerto Montt 5501842, Chile; (M.M.d.O.); (D.C.); (K.K.)
| | - Yoandy Coca
- Doctorado en Ciencias de la Ingeniería, Departamento de Ingeniería Química y Bioprocesos, Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago 7820436, Chile;
| | - Harry Bohle
- Laboratorio InnovoGen, Egaña 198 Piso 2, Puerto Montt 5502534, Chile;
| | - Sion Bayliss
- Bristol Veterinary School, University of Bristol, Bristol BS8 1QU, UK;
| | - Molly Kibenge
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown, PE C1A 4P3, Canada; (M.K.); (F.K.)
| | - Frederick Kibenge
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown, PE C1A 4P3, Canada; (M.K.); (F.K.)
| |
Collapse
|
2
|
Fajardo C, Santos P, Passos R, Vaz M, Azeredo R, Machado M, Fernández-Boo S, Baptista T, Costas B. Early Molecular Immune Responses of Turbot ( Scophthalmus maximus L.) Following Infection with Aeromonas salmonicida subsp. salmonicida. Int J Mol Sci 2023; 24:12944. [PMID: 37629124 PMCID: PMC10454659 DOI: 10.3390/ijms241612944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/14/2023] [Accepted: 08/16/2023] [Indexed: 08/27/2023] Open
Abstract
Turbot aquaculture production is an important economic activity in several countries around the world; nonetheless, the incidence of diseases, such furunculosis, caused by the etiological agent A. salmonicida subsp. salmonicida, is responsible for important losses to this industry worldwide. Given this perspective, this study aimed to evaluate early immune responses in turbot (S. maximus L.) following infection with A. salmonicida subsp. salmonicida. For this, 72 fish were individually weighed and randomly distributed into 6 tanks in a circulating seawater system. For the bacterial challenge, half of the individuals (3 tanks with 36 individuals) were infected using a peritoneal injection with the bacterial suspension, while the other half of individuals were injected with PBS and kept as a control group. Several factors linked to the innate immune response were studied, including not only haematological (white blood cells, red blood cells, haematocrit, haemoglobin, mean corpuscular volume, mean cell haemoglobin, mean corpuscular haemoglobin concentration, neutrophils, monocytes, lymphocytes, thrombocytes) and oxidative stress parameters, but also the analyses of the expression of 13 key immune-related genes (tnf-α, il-1β, il-8, pparα-1, acox1, tgf-β1, nf-kB p65, srebp-1, il-10, c3, cpt1a, pcna, il-22). No significant differences were recorded in blood or innate humoral parameters (lysozyme, anti-protease, peroxidase) at the selected sampling points. There was neither any evidence of significant changes in the activity levels of the oxidative stress indicators (catalase, glutathione S-transferase, lipid peroxidation, superoxide dismutase). In contrast, pro-inflammatory (tnf-α, il-1β), anti-inflammatory (il-10), and innate immune-related genes (c3) were up-regulated, while another gene linked with the lipid metabolism (acox1) was down-regulated. The results showed new insights about early responses of turbot following infection with A. salmonicida subsp. salmonicida.
Collapse
Affiliation(s)
- Carlos Fajardo
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, 4450-208 Porto, Portugal; (C.F.); (P.S.); (R.A.); (M.M.); (S.F.-B.)
- MARE—Marine and Environmental Sciences Centre, ESTM, Polytechnic Institute of Leiria, 2520-620 Peniche, Portugal; (R.P.); (M.V.); (T.B.)
- Department of Biology, Faculty of Marine and Environmental Sciences, Instituto Universitario de Investigación Marina (INMAR), Campus de Excelencia Internacional del Mar (CEI·MAR), University of Cadiz (UCA), 11510 Puerto Real, Spain
| | - Paulo Santos
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, 4450-208 Porto, Portugal; (C.F.); (P.S.); (R.A.); (M.M.); (S.F.-B.)
- MARE—Marine and Environmental Sciences Centre, ESTM, Polytechnic Institute of Leiria, 2520-620 Peniche, Portugal; (R.P.); (M.V.); (T.B.)
- Department of Aquatic Production, School of Biomedicine and Biomedical Sciences, Abel Salazar Institute of Biomedical Sciences (ICBAS), University of Porto, 4050-313 Porto, Portugal
| | - Ricardo Passos
- MARE—Marine and Environmental Sciences Centre, ESTM, Polytechnic Institute of Leiria, 2520-620 Peniche, Portugal; (R.P.); (M.V.); (T.B.)
| | - Mariana Vaz
- MARE—Marine and Environmental Sciences Centre, ESTM, Polytechnic Institute of Leiria, 2520-620 Peniche, Portugal; (R.P.); (M.V.); (T.B.)
| | - Rita Azeredo
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, 4450-208 Porto, Portugal; (C.F.); (P.S.); (R.A.); (M.M.); (S.F.-B.)
| | - Marina Machado
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, 4450-208 Porto, Portugal; (C.F.); (P.S.); (R.A.); (M.M.); (S.F.-B.)
| | - Sergio Fernández-Boo
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, 4450-208 Porto, Portugal; (C.F.); (P.S.); (R.A.); (M.M.); (S.F.-B.)
| | - Teresa Baptista
- MARE—Marine and Environmental Sciences Centre, ESTM, Polytechnic Institute of Leiria, 2520-620 Peniche, Portugal; (R.P.); (M.V.); (T.B.)
| | - Benjamin Costas
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, 4450-208 Porto, Portugal; (C.F.); (P.S.); (R.A.); (M.M.); (S.F.-B.)
- Department of Aquatic Production, School of Biomedicine and Biomedical Sciences, Abel Salazar Institute of Biomedical Sciences (ICBAS), University of Porto, 4050-313 Porto, Portugal
| |
Collapse
|
3
|
A novel portable label-free electrochemical immunosensor for ultrasensitive detection of Aeromonas salmonicida in aquaculture seawater. Anal Bioanal Chem 2022; 414:6591-6600. [PMID: 35915251 DOI: 10.1007/s00216-022-04219-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 06/28/2022] [Accepted: 07/04/2022] [Indexed: 11/01/2022]
Abstract
Infectious diseases caused by Aeromonas salmonicida (A. salmonicida) have a huge impact and produce significant losses in aquaculture and fish farming. Fish pathogen early detection is a critical step for the rapid identification and prevention of these problems. This work presents a novel portable label-free ultrasensitive electrochemical immunosensor for A. salmonicida detection in seawater. It consists of a fluidic integrated electrochemical-cell-chip (ECC) with independent chambers enclosing three electrochemical cells (ECs). Anti-A. salmonicida (AbSalm) antibodies were covalently attached to the gold surface of the microfabricated electrodes and were used for the sensitive detection of A. salmonicida. The antibody-antigen immunoreaction was studied by enzyme-linked immunosorbent assay (ELISA), and the surface functionalization was characterized by using quartz crystal microbalance (QCM), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The performance of the developed immunosensor, in terms of sensitivity, repeatability, and specificity, was also studied. The linear working range varied between 1 and 107 CFU mL-1, with a limit of detection (LOD) as low as 1 CFU mL-1. The suitability of the immunosensor for real sample detection was successfully demonstrated via recovery studies performed in spiked seawater samples. The proposed technology supports the use of low-cost and portable instrumentation that concedes the ultrasensitive, simple, and fast quantification of the A. salmonicida. To the best of our knowledge, this is the first portable sensing system for the detection of A. salmonicida in seawater samples, which provides a promising online monitoring platform for the detection of this bacterium in aquaculture facilities.
Collapse
|
4
|
Teffer AK, Hinch SG, Miller KM, Patterson DA, Bass AL, Cooke SJ, Farrell AP, Beacham TD, Chapman JM, Juanes F. Host-pathogen-environment interactions predict survival outcomes of adult sockeye salmon (Oncorhynchus nerka) released from fisheries. Mol Ecol 2021; 31:134-160. [PMID: 34614262 DOI: 10.1111/mec.16214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 09/22/2021] [Accepted: 09/30/2021] [Indexed: 11/27/2022]
Abstract
Incorporating host-pathogen(s)-environment axes into management and conservation planning is critical to preserving species in a warming climate. However, the role pathogens play in host stress resilience remains largely unexplored in wild animal populations. We experimentally characterized how independent and cumulative stressors (fisheries handling, high water temperature) and natural infections affected the health and longevity of released wild adult sockeye salmon (Oncorhynchus nerka) in British Columbia, Canada. Returning adults were collected before and after entering the Fraser River, yielding marine- and river-collected groups, respectively (N = 185). Fish were exposed to a mild (seine) or severe (gill net) fishery treatment at collection, and then held in flow-through freshwater tanks for up to four weeks at historical (14°C) or projected migration temperatures (18°C). Using weekly nonlethal gill biopsies and high-throughput qPCR, we quantified loads of up to 46 pathogens with host stress and immune gene expression. Marine-collected fish had less severe infections than river-collected fish, a short migration distance (100 km, 5-7 days) that produced profound infection differences. At 14°C, river-collected fish survived 1-2 weeks less than marine-collected fish. All fish held at 18°C died within 4 weeks unless they experienced minimal handling. Gene expression correlated with infections in river-collected fish, while marine-collected fish were more stressor-responsive. Cumulative stressors were detrimental regardless of infections or collection location, probably due to extreme physiological disturbance. Because river-derived infections correlated with single stressor responses, river entry probably decreases stressor resilience of adult salmon by altering both physiology and pathogen burdens, which redirect host responses toward disease resistance.
Collapse
Affiliation(s)
- Amy K Teffer
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada.,Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Scott G Hinch
- Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kristina M Miller
- Fisheries and Oceans Canada, Pacific Biological Station, Nanaimo, British Columbia, Canada
| | - David A Patterson
- Fisheries and Oceans Canada, Cooperative Resource Management Institute, School of Resource and Environmental Management, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Arthur L Bass
- Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Steven J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Anthony P Farrell
- Department of Zoology, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - Terry D Beacham
- Fisheries and Oceans Canada, Pacific Biological Station, Nanaimo, British Columbia, Canada
| | - Jacqueline M Chapman
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Francis Juanes
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| |
Collapse
|
5
|
Papadopoulou A, Davie A, Monaghan SJ, Migaud H, Adams A. Development of diagnostic assays for differentiation of atypical Aeromonas salmonicida vapA type V and type VI in ballan wrasse (Labrus bergylta, Ascanius). JOURNAL OF FISH DISEASES 2021; 44:711-719. [PMID: 33493378 DOI: 10.1111/jfd.13334] [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: 08/15/2020] [Revised: 12/29/2020] [Accepted: 12/30/2020] [Indexed: 06/12/2023]
Abstract
Aeromonas salmonicida (As) is a highly heterogeneous bacterial species, and strains' host specificity has been reported. Ballan wrasse (Labrus bergylta Ascanius, 1767) is susceptible to atypical As (aAs) vapA type V and type VI in Scotland and Norway. Identification of the bacterium is achieved by culture and molecular techniques; however, the available methods used to distinguish the As types are costly and time-consuming. This paper describes the development of a PCR and a restriction enzyme assay for the detection of aAs vapA type V and type VI in ballan wrasse, respectively. Type V-specific primers were designed on conserved regions of the vapA gene, and the restriction enzyme assay was performed on the PCR products of the hypervariable region of vapA gene for the detection of type VI isolates. Amplification product was produced for type V (254 bp) and restriction bands (368 and 254 bp) for type VI isolates only. In addition, the assays detected type V and type VI isolates in spiked water samples and type V in diagnostic tissue samples. The assays are fast, specific and cost-effective and can be used as specific diagnostic tools for cleaner fish, to detect infectious divergence strains, and to manage and mitigate aAs disease outbreaks through vaccine development.
Collapse
Affiliation(s)
- Athina Papadopoulou
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Andrew Davie
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Sean J Monaghan
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Herve Migaud
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Alexandra Adams
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| |
Collapse
|
6
|
Lian Z, Bai J, Hu X, Lü A, Sun J, Guo Y, Song Y. Detection and characterization of Aeromonas salmonicida subsp. salmonicida infection in crucian carp Carassius auratus. Vet Res Commun 2020; 44:61-72. [PMID: 32472344 DOI: 10.1007/s11259-020-09773-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 10/24/2022]
Abstract
Aeromonas salmonicida is one of the most important pathogens in salmonids and non-salmonids species. Nevertheless, very little was reported in cyprinids about A. salmonicida infection. Hence, a pathogenic A. salmonicida subsp. salmonicida, namely isolate GCA-518, was isolated from diseased crucian carp Carassius auratus. Its optimal growth conditions were at 28 °C, pH 7.0 and 1.5% NaCl. Furthermore, the quantitative real-time PCR (qPCR) targeting serine protease (aspA) gene was established for rapid detection of the lowest limit of 5.6 × 102 copies per reaction. The pathogenicity was confirmed in crucian carp by intraperitoneal infection. Histopathologic examination displayed multifocal necrosis and infiltration of inflammatory cells in gill, liver, kidney and intestine. This is the first report on typical A. salmonicida infection in cultured crucian carp.
Collapse
Affiliation(s)
- Zhengyi Lian
- Tianjin Key Lab of Aqua-Ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, Tianjin, 300384, China
| | - Jie Bai
- Tianjin Key Lab of Aqua-Ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, Tianjin, 300384, China
| | - Xiucai Hu
- Tianjin Key Lab of Aqua-Ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, Tianjin, 300384, China
| | - Aijun Lü
- Tianjin Key Lab of Aqua-Ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, Tianjin, 300384, China.
| | - Jingfeng Sun
- Tianjin Key Lab of Aqua-Ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, Tianjin, 300384, China
| | - Yongjun Guo
- Tianjin Key Lab of Aqua-Ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, Tianjin, 300384, China
| | - Yajiao Song
- Tianjin Key Lab of Aqua-Ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, Tianjin, 300384, China
| |
Collapse
|
7
|
Chapman JM, Teffer AK, Bass AL, Hinch SG, Patterson DA, Miller KM, Cooke SJ. Handling, infectious agents and physiological condition influence survival and post-release behaviour in migratory adult coho salmon after experimental displacement. CONSERVATION PHYSIOLOGY 2020; 8:coaa033. [PMID: 32440351 PMCID: PMC7233283 DOI: 10.1093/conphys/coaa033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 02/24/2020] [Accepted: 03/31/2020] [Indexed: 06/11/2023]
Abstract
For Pacific salmon captured and released by fisheries, post-release behaviour and survival may be influenced by their health and condition at time of capture. We sought to characterize the interactions between infectious agent burden, fish immune and stress physiology and fisheries stressors to investigate the potential for capture-mediated pathogen-induced mortality in adult coho salmon Oncorhynchus kisutch. We used radio-telemetry paired with high-throughput qPCR of non-lethal gill biopsies for infectious agents and host biomarkers from 200 tagged fish experimentally displaced and exposed to various experimental fisheries treatments (gill net entanglement, recreational angling and recreational angling with air exposure vs. non-sampled control). We characterized relationships among post-release behaviour and survival, infectious agent presence and loads, physiological parameters and transcription profiles of stress and immune genes. All infectious agents detected were endemic and in loads consistent with previous adult Pacific salmon monitoring. Individuals exposed to fisheries treatments were less likely to reach spawning habitat compared to controls, and handling duration independent of fisheries gear had a negative effect on survival. High infectious agent burden was associated with accelerated migration initiation post-release, revealing behavioural plasticity in response to deteriorating condition in this semelparous species. Prevalence and load of infectious agents increased post-migration as well as transcription signatures reflected changes in immune and stress profiles consistent with senescence. Results from this study further our understanding of factors associated with fisheries that increase risk of post-release mortality and characterize some physiological mechanisms that underpin migratory behaviour.
Collapse
Affiliation(s)
- J M Chapman
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6 Canada
| | - A K Teffer
- Pacific Salmon Ecology Laboratory, Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada. Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - A L Bass
- Pacific Salmon Ecology Laboratory, Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada. Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - S G Hinch
- Pacific Salmon Ecology Laboratory, Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada. Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - D A Patterson
- Pacific Salmon Ecology Laboratory, Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada. Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- Cooperative Resource Management Institute, School of Resource and Environmental Management, Fisheries and Oceans Canada, Burnaby, BC, Canada. Fisheries and Oceans Canada, Cooperative Resource Management Institute, School of Resource and Environmental Management, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - K M Miller
- Fisheries and Oceans Canada, Molecular Genetics Section, Pacific Biological Station, Nanaimo, BC V9T 6N7, Canada
| | - S J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6 Canada
| |
Collapse
|
8
|
Teffer AK, Hinch S, Miller K, Jeffries K, Patterson D, Cooke S, Farrell A, Kaukinen KH, Li S, Juanes F. Cumulative Effects of Thermal and Fisheries Stressors Reveal Sex-Specific Effects on Infection Development and Early Mortality of Adult Coho Salmon ( Oncorhynchus kisutch). Physiol Biochem Zool 2020; 92:505-529. [PMID: 31397628 DOI: 10.1086/705125] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Multiple stressors are commonly encountered by wild animals, but their cumulative effects are poorly understood, especially regarding infection development. We conducted a holding study with repeated gill and blood sampling to characterize the effects of cumulative stressors on infection development in adult coho salmon. Treatments included chronic thermal stress (15°C vs. 10°C) and acute gill net entanglement with an air exposure (simulating fisheries bycatch release). The potential loadings of 35 infectious agents and the expression of 17 host immune genes were quantified using high-throughput quantitative polymerase chain reaction, while host physiology was characterized with chemical analysis of blood. Temporal increases in infectious agent richness and loads were concurrent with decreased expression of immune genes in fish sampled in the river. In the laboratory, mortality was minimal in cool water regardless of fishery treatment (<15%). Elevated water temperature under laboratory conditions increased mortality of males and females (8% and 28% mortality, respectively, delayed by >1 wk) and enhanced mortality associated with handling and biopsy (∼40% both sexes). Experimental gillnetting at high temperature further enhanced female mortality (73%). Fish held at high temperature demonstrated heavier infectious agent loads, osmoregulatory impairment, suppressed female maturation, and upregulation of inflammatory and extracellular immune genes. At high temperature, heavy Parvicapsula minibicornis loads were associated with premature mortality. Females exhibited physiological impairment from both stressors after 1 wk, and infection burdens correlated poorly with immune gene regulation compared with males. Cumulative effects of multiple stressors on female mortality are likely a function of physiological impairment and enhanced infections at high temperature.
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
McMurtrie J, Verner-Jeffreys DW, Cochrane-Dyet T, White P, van Aerle R, Ryder D, Stone D, Green M, Feist SW, Cano I. Health assessment of the cleaner fish ballan wrasse Labrus bergylta from the British south-west coast. DISEASES OF AQUATIC ORGANISMS 2019; 136:133-146. [PMID: 31621646 DOI: 10.3354/dao03394] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Wild-caught ballan wrasse Labrus bergylta are translocated en masse from the British south-west coast to Scotland for use as cleaner fish to tackle Atlantic salmon Salmo salar sea lice infestations; however, very little is known about the background health status of this species. This is the first health assessment of wild ballan wrasse from the British south-west. Wild-caught ballan wrasse (n = 75) from coastal populations off Dorset and Cornwall were subjected to a full health screen for viral, bacterial and parasitic infections and associated pathology. A range of metazoan and protozoan parasites were observed in histological sections, including copepods (sea lice Caligus centrodonti), nematodes, cestodes, digenean metacercariae, Cryptocaryon-like ciliates and an intestinal coccidian (Eimeria sp.) observed in 26.6% of the samples. The mycoplasma Acholeplasma laidlawii was associated with cytopathic effect in cell culture inoculated with tissue homogenates. The opportunistic pathogen Photobacterium damselae damselae was isolated from a single fish with a systemic infection. The isolate was confirmed to possess the virulence factors hlyAch and plpV, previously associated with cell toxicity and pathogenicity to fish. There are no immediate concerns for the continued mass translation of ballan wrasse, however careful monitoring of the population is recommended.
Collapse
Affiliation(s)
- Jamie McMurtrie
- Cefas Weymouth Laboratory, Centre for Environment, Fisheries and Aquaculture Science, Weymouth DT4 8UB, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Teffer AK, Miller KM. A Comparison of Nonlethal and Destructive Methods for Broad-Based Infectious Agent Screening of Chinook Salmon Using High-Throughput qPCR. JOURNAL OF AQUATIC ANIMAL HEALTH 2019; 31:274-289. [PMID: 31343778 DOI: 10.1002/aah.10079] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 07/20/2019] [Indexed: 06/10/2023]
Abstract
Molecular tools, such as high-throughput quantitative polymerase chain reaction (HT-qPCR), are useful for monitoring multiple infectious agents in wild animal populations (i.e., broad-based screening). If destructive tissue samples cannot be obtained due to experimental design requirements (e.g., bio-telemetry; holding with repeated biopsy) or the conservation status of host species, then nonlethally sampled tissues can be substituted. However, infection profiles have been found to differ between nonlethally and destructively sampled tissues. We present a comparative analysis of nonlethal (gill and blood) and destructive (pool of internal and external tissue) approaches for broad-based infectious agent screening of adult Chinook Salmon Oncorhynchus tshawytscha. Of a possible 47 agents, 16 were detected overall by nonlethal and destructive methods. Our results indicated moderate differences in infection profiles among tissues, with limitations of each tissue type dependent on the ecology of each agent. The gill was the most comprehensive screening tissue, as more infectious agents were detected overall in gill (n = 16) than in blood (n = 12) or multi-tissue pools (n = 15). The agreement in the estimated agent prevalence between tissue types ranged from poor to excellent, while overall agent community structure (the combined prevalence of all agents) showed low agreement between tissue types. Two agents occurred at 100% prevalence in all tissue types. Nine agents, including types of bacteria and gill parasites, were more prevalent in gill than in blood, while five agents, including one virus and several microparasites, were more prevalent in blood. Future studies should pair microscopy and histopathology with HT-qPCR to better characterize host health and disease development relative to molecular detection of agents across tissue types.
Collapse
Affiliation(s)
- Amy K Teffer
- Department of Biology, University of Victoria, Post Office Box 1700, Station CSC, Victoria, British Columbia, V8W 2Y2, Canada
| | - Kristina M Miller
- Fisheries and Oceans Canada, Molecular Genetics Section, Pacific Biological Station, 3190 Hammond Bay Road, Nanaimo, British Columbia, V9T 6N7, Canada
| |
Collapse
|
12
|
Draft Genome Sequence of the Type Strain Aeromonas salmonicida subsp. salmonicida ATCC 33658. GENOME ANNOUNCEMENTS 2017; 5:5/40/e01064-17. [PMID: 28982999 PMCID: PMC5629056 DOI: 10.1128/genomea.01064-17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Here, we report the draft genome sequence of the type strain Aeromonas salmonicida subsp. salmonicida ATCC 33658 isolated from Salmo salar The size of the genome is 4,728,143 bp with a G+C content of 58.5%. The A. salmonicida subsp. salmonicida ATCC 33658 genome lacks essential virulence genes that were likely lost during genomic rearrangements.
Collapse
|
13
|
Assis GBN, de Oliveira TF, Gardner IA, Figueiredo HCP, Leal CAG. Sensitivity and specificity of real-time PCR and bacteriological culture for francisellosis in farm-raised Nile tilapia (Oreochromis niloticus L.). JOURNAL OF FISH DISEASES 2017; 40:785-795. [PMID: 27670740 DOI: 10.1111/jfd.12559] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/09/2016] [Accepted: 08/11/2016] [Indexed: 06/06/2023]
Abstract
Despite the worldwide occurrence of Francisella noatunensis subsp. orientalis (Fno) infection in farmed tilapia, sensitivity and specificity estimates of commonly used diagnostic tests have not been reported. This study aimed to estimate the sensitivity and specificity of bacteriological culture and qPCR to detect Fno infection. We tested 559 fish, sampled from four farms with different epidemiological scenarios: (i) healthy fish in a hatchery free of Fno; (ii) targeted sampling of diseased fish with suggestive external clinical signs of francisellosis during an outbreak; (iii) convenience sampling of diseased and clinically healthy fish during an outbreak; and (iv) sampling of healthy fish in a cage farm without a history of outbreaks, but with francisellosis reported in other farms in the same reservoir. The qPCR had higher median sensitivity (range, 48.8-99.5%) than culture (range, 1.6-74.4%). Culture had a substantially lower median sensitivity (1.6%) than qPCR (48.8%) to detect Fno in carrier tilapia (farm 4). Median specificity estimates for both tests were >99.2%. The qPCR is the superior test for use in surveillance and monitoring programmes for francisellosis in farmed Nile tilapia, but both tests have high sensitivity and specificity which make them fit for use in the diagnosis of Fno outbreaks.
Collapse
Affiliation(s)
- G B N Assis
- AQUAVET, Laboratory of Aquatic Animal Diseases, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - T F de Oliveira
- AQUAVET, Laboratory of Aquatic Animal Diseases, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - I A Gardner
- Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - H C P Figueiredo
- AQUAVET, Laboratory of Aquatic Animal Diseases, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
- AQUACEN - National Reference Laboratory of Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - C A G Leal
- AQUAVET, Laboratory of Aquatic Animal Diseases, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
- AQUACEN - National Reference Laboratory of Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| |
Collapse
|
14
|
Brosnahan CL, Humphrey S, Knowles G, Ha HJ, Pande A, Jones JB. Nocardiosis in freshwater reared Chinook salmon (Oncorhynchus tshawytscha). N Z Vet J 2017; 65:214-218. [DOI: 10.1080/00480169.2017.1314794] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- CL Brosnahan
- Animal Health Laboratory, Ministry for Primary Industries, 66 Ward Street, Upper Hutt, New Zealand
| | - S Humphrey
- Animal Health Laboratory, Ministry for Primary Industries, 66 Ward Street, Upper Hutt, New Zealand
| | - G Knowles
- Vetman Animal Health, 25 Fruitgrowers Rd, PO Box 44, Clyde, New Zealand
| | - HJ Ha
- Animal Health Laboratory, Ministry for Primary Industries, 66 Ward Street, Upper Hutt, New Zealand
| | - A Pande
- Animal Health Laboratory, Ministry for Primary Industries, 66 Ward Street, Upper Hutt, New Zealand
| | - JB Jones
- Animal Health Laboratory, Ministry for Primary Industries, 66 Ward Street, Upper Hutt, New Zealand
| |
Collapse
|
15
|
Teffer AK, Hinch SG, Miller KM, Patterson DA, Farrell AP, Cooke SJ, Bass AL, Szekeres P, Juanes F. Capture severity, infectious disease processes and sex influence post-release mortality of sockeye salmon bycatch. CONSERVATION PHYSIOLOGY 2017; 5:cox017. [PMID: 28852514 PMCID: PMC5569998 DOI: 10.1093/conphys/cox017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 02/17/2017] [Accepted: 03/07/2017] [Indexed: 05/21/2023]
Abstract
Bycatch is a common occurrence in heavily fished areas such as the Fraser River, British Columbia, where fisheries target returning adult Pacific salmon (Oncorhynchus spp.) en route to spawning grounds. The extent to which these encounters reduce fish survival through injury and physiological impairment depends on multiple factors including capture severity, river temperature and infectious agents. In an effort to characterize the mechanisms of post-release mortality and address fishery and managerial concerns regarding specific regulations, wild-caught Early Stuart sockeye salmon (Oncorhynchus nerka) were exposed to either mild (20 s) or severe (20 min) gillnet entanglement and then held at ecologically relevant temperatures throughout their period of river migration (mid-late July) and spawning (early August). Individuals were biopsy sampled immediately after entanglement and at death to measure indicators of stress and immunity, and the infection intensity of 44 potential pathogens. Biopsy alone increased mortality (males: 33%, females: 60%) when compared with non-biopsied controls (males: 7%, females: 15%), indicating high sensitivity to any handling during river migration, especially among females. Mortality did not occur until 5-10 days after entanglement, with severe entanglement resulting in the greatest mortality (males: 62%, females: 90%), followed by mild entanglement (males: 44%, females: 70%). Infection intensities of Flavobacterium psychrophilum and Ceratonova shasta measured at death were greater in fish that died sooner. Physiological indicators of host stress and immunity also differed depending on longevity, and indicated anaerobic metabolism, osmoregulatory failure and altered immune gene regulation in premature mortalities. Together, these results implicate latent effects of entanglement, especially among females, resulting in mortality days or weeks after release. Although any entanglement is potentially detrimental, reducing entanglement durations can improve post-release survival.
Collapse
Affiliation(s)
- Amy K. Teffer
- Department of Biology, University of Victoria, Victoria, BC V8P 5C2, Canada
- Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Scott G. Hinch
- Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Kristi M. Miller
- Fisheries and Oceans Canada, Molecular Genetics Section, Pacific Biological Station, Nanaimo, BC V9T 6N7, Canada
| | - David A. Patterson
- Fisheries and Oceans Canada, Cooperative Resource Management Institute, School of Resource and Environmental Management, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Anthony P. Farrell
- Department of Zoology, Department of Land and Food Systems, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Steven J. Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Arthur L. Bass
- Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Petra Szekeres
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Francis Juanes
- Department of Biology, University of Victoria, Victoria, BC V8P 5C2, Canada
| |
Collapse
|
16
|
Bartkova S, Kokotovic B, Skall HF, Lorenzen N, Dalsgaard I. Detection and quantification of Aeromonas salmonicida in fish tissue by real-time PCR. JOURNAL OF FISH DISEASES 2017; 40:231-242. [PMID: 27193829 DOI: 10.1111/jfd.12505] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 04/21/2016] [Accepted: 04/21/2016] [Indexed: 06/05/2023]
Abstract
Furunculosis, a septicaemic infection caused by the bacterium Aeromonas salmonicida subsp. salmonicida, currently causes problems in Danish seawater rainbow trout production. Detection has mainly been achieved by bacterial culture, but more rapid and sensitive methods are needed. A previously developed real-time PCR assay targeting the plasmid encoded aopP gene of A. salmonicida was, in parallel with culturing, used for the examination of five organs of 40 fish from Danish freshwater and seawater farms. Real-time PCR showed overall a higher frequency of positives than culturing (65% of positive fish by real-time PCR compared to 30% by a culture approach). Also, no real-time PCR-negative samples were found positive by culturing. A. salmonicida was detected by real-time PCR, though not by culturing, in freshwater fish showing no signs of furunculosis, indicating possible presence of carrier fish. In seawater fish examined after an outbreak and antibiotics treatment, real-time PCR showed the presence of the bacterium in all examined organs (1-482 genomic units mg-1 ). With a limit of detection of 40 target copies (1-2 genomic units) per reaction, a high reproducibility and an excellent efficiency, the present real-time PCR assay provides a sensitive tool for the detection of A. salmonicida.
Collapse
Affiliation(s)
- S Bartkova
- National Veterinary Institute, Section for Bacteriology and Pathology, Technical University of Denmark, Frederiksberg C, Denmark
| | - B Kokotovic
- National Veterinary Institute, Section for Bacteriology and Pathology, Technical University of Denmark, Frederiksberg C, Denmark
| | - H F Skall
- Department of Animal Science, Aarhus University, Aarhus N, Denmark
| | - N Lorenzen
- Department of Animal Science, Aarhus University, Aarhus N, Denmark
| | - I Dalsgaard
- National Veterinary Institute, Section for Bacteriology and Pathology, Technical University of Denmark, Frederiksberg C, Denmark
| |
Collapse
|
17
|
Fernández-Álvarez C, González SF, Santos Y. Development of a SYBR green I real-time PCR assay for specific identification of the fish pathogen Aeromonas salmonicida subspecies salmonicida. Appl Microbiol Biotechnol 2016; 100:10585-10595. [PMID: 27838837 DOI: 10.1007/s00253-016-7929-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 10/03/2016] [Accepted: 10/10/2016] [Indexed: 10/20/2022]
Abstract
A SYBR Green I real-time polymerase chain reaction protocol for specific detection of the fish pathogen Aeromonas salmonicida subsp. salmonicida was developed and validated for rapid diagnosis of typical furunculosis. The sequence of the aopO gene of A. salmonicida subsp. salmonicida, which encodes for a serine/threonine protein kinase linked to virulence, was chosen for primer design. The selected primers amplified a 119-bp internal fragment of the aopO gene. The specificity test proved that 100 % (40/40) of the A. salmonicida subsp. salmonicida strains tested showed a positive amplification with subspecies-specific melting temperatures (Tm) of 80.75 ± 0.35 °C. Atypical A. salmonicida subspecies and other non-related bacterial fish pathogens did not amplify or showed unspecific melting profiles, except for one strain of A. salmonicida subsp. achromogenes and one strain of A. salmonicida subsp. smithia. The detection sensitivity was 21 fg of purified bacterial DNA per reaction, corresponding to 1-2 bacterial cells and 6-60 bacteria per reaction for seeded kidney and blood. The assay was highly reproducible with low variation coefficient values for intra-run and inter-run assays. The assay also allowed the specific detection of A. salmonicida subsp. salmonicida in tissues of fish naturally and experimentally infected. No amplification was detected when tissues from healthy fish or fish affected by other diseases were tested. The SYBR Green real-time PCR and melt curve analysis developed in this study is a rapid and accurate method for the specific identification of A. salmonicida subsp. salmonicida isolates and its detection on tissues of fish affected by furunculosis.
Collapse
Affiliation(s)
- Clara Fernández-Álvarez
- Departamento de Microbiología y Parasitología, Edificio CIBUS Facultad de Biología and Instituto de Investigación y Análisis Alimentario, Universidad de Santiago de Compostela, 15782, Santiago de Compostela, Spain.
| | - Santiago F González
- Institute for Research in Biomedicine, Università della Suvizzera Italiana, 6500, Bellinzona, Switzerland
| | - Ysabel Santos
- Departamento de Microbiología y Parasitología, Edificio CIBUS Facultad de Biología and Instituto de Investigación y Análisis Alimentario, Universidad de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| |
Collapse
|
18
|
Gulla S, Duodu S, Nilsen A, Fossen I, Colquhoun DJ. Aeromonas salmonicida infection levels in pre- and post-stocked cleaner fish assessed by culture and an amended qPCR assay. JOURNAL OF FISH DISEASES 2016; 39:867-877. [PMID: 26514414 DOI: 10.1111/jfd.12420] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 08/28/2015] [Accepted: 08/28/2015] [Indexed: 06/05/2023]
Abstract
Due to increasing resistance to chemical therapeutants, the use of 'cleaner fish' (primarily wrasse, Labridae, species) has become popular in European salmon farming for biocontrol of the salmon louse, Lepeophtheirus salmonis (Krøyer). While being efficient de-licers, cleaner fish mortality levels in salmon cages are commonly high, and systemic bacterial infections constitute a major problem. Atypical furunculosis, caused by Aeromonas salmonicida A-layer types V and VI, is among the most common diagnoses reached in clinical investigations. A previously described real-time PCR (qPCR), targeting the A. salmonicida A-layer gene (vapA), was modified and validated for specific and sensitive detection of all presently recognized A-layer types of this bacterium. Before stocking and during episodes of increased mortality in salmon cages, cleaner fish (primarily wild-caught wrasse) were sampled and screened for A. salmonicida by qPCR and culture. Culture indicated that systemic bacterial infections are mainly contracted after salmon farm stocking, and qPCR revealed A. salmonicida prevalences of approximately 4% and 68% in pre- and post-stocked cleaner fish, respectively. This underpins A. salmonicida's relevance as a contributing factor to cleaner fish mortality and emphasizes the need for implementation of preventive measures (e.g. vaccination) if current levels of cleaner fish use are to be continued or expanded.
Collapse
Affiliation(s)
- S Gulla
- Norwegian Veterinary Institute, Oslo/Trondheim, Norway
- Vaxxinova Norway AS, Bergen, Norway
| | - S Duodu
- Norwegian Veterinary Institute, Oslo/Trondheim, Norway
| | - A Nilsen
- Norwegian Veterinary Institute, Oslo/Trondheim, Norway
| | - I Fossen
- Møreforskning AS, Kristiansund, Norway
| | - D J Colquhoun
- Norwegian Veterinary Institute, Oslo/Trondheim, Norway
- Institute for Biology, University of Bergen, Bergen, Norway
| |
Collapse
|
19
|
Menanteau-Ledouble S, Kumar G, Saleh M, El-Matbouli M. Aeromonas salmonicida: updates on an old acquaintance. DISEASES OF AQUATIC ORGANISMS 2016; 120:49-68. [PMID: 27304870 DOI: 10.3354/dao03006] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Aeromonas salmonicida is the oldest known infectious agent to be linked to fish disease and constitutes a major bacterial pathogen of fish, in particular of salmonids. This bacterium can be found almost worldwide in both marine and freshwater environments and has been divided into several sub-species. In this review, we present the most recent developments concerning our understanding of this pathogen, including how the characterization of new isolates from non-salmonid hosts suggests a more nuanced picture of the importance of the so‑called 'atypical isolates'. We also describe the clinical presentation regarding the infection across several fish species and discuss what is known about the virulence of A. salmonicida and, in particular, the role that the type 3 secretion system might play in suppressing the immune response of its hosts. Finally, isolates have displayed varied levels of antibiotic resistance. Hence, we review a number of solutions that have been developed both to prevent outbreaks and to treat them once they occur, including the application of pre- and probiotic supplements.
Collapse
Affiliation(s)
- Simon Menanteau-Ledouble
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
| | | | | | | |
Collapse
|