1
|
Twardek WM, Chapman JM, Miller KM, Beere MC, Li S, Kaukinen KH, Danylchuk AJ, Cooke SJ. Evidence of a hydraulically challenging reach serving as a barrier for the upstream migration of infection-burdened adult steelhead. CONSERVATION PHYSIOLOGY 2019; 7:coz023. [PMID: 31191906 PMCID: PMC6553125 DOI: 10.1093/conphys/coz023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Revised: 04/15/2019] [Accepted: 04/30/2019] [Indexed: 05/04/2023]
Abstract
Anadromous fishes such as steelhead trout, Oncorhynchus mykiss, are exposed to a suite of infectious agents and migratory challenges during their freshwater migrations. We assessed infectious agent load and richness and immune system gene expression in gill tissue of Bulkley River (British Columbia, CA) steelhead captured at and upstream of a migratory barrier to evaluate whether infectious burdens impacted migration success. We further considered the potential influences of water temperature, sex and fish size on host infectious agents and transcription profiles. There were eight infectious agents detected in steelhead gill tissue, with high prevalence of the bacteria Candidatus Branchiomonas cysticola (80%) and Flavobacterium psychrophilum (95%) and the microparasite Sphaerothecum destruens (53%). Fish sampled at the falls had significantly greater relative loads of Ca. B. cysticola and F. psychrophilum, higher infectious agent richness and differential gene expression compared to fish captured upstream. Flavobacterium psychrophilum was only associated with immune gene expression (particularly humoral immunity) of fish sampled at the falls, while water temperature was positively correlated with genes involved in the complement system, metabolic stress and oxidative stress for fish captured upstream. This work highlights interesting differences in agent-host interactions across fisheries and suggests that hydraulic barriers may reduce the passage of fish with the heaviest infectious agent burdens, emphasizing the selective role of areas of difficult passage. Further, this work expands our knowledge of infectious agent prevalence in wild salmonids and provides insight into the relationships between infectious agents and host physiology.
Collapse
Affiliation(s)
- W M Twardek
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, Colonel By Dr., Ottawa, ON, Canada
- Corresponding author: Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, 1125 Colonel By Dr., Ottawa, ON, K1S 5B6, Canada. Tel: +613 986 3786.
| | - J M Chapman
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, Colonel By Dr., Ottawa, ON, Canada
| | - K M Miller
- Fisheries and Oceans Canada, Pacific Biological Station, Hammond Bay Rd, Nanaimo, BC, Canada
| | - M C Beere
- British Columbia Ministry of Forests, Lands, Natural Resource Operations and Rural Development, Fisheries Branch, Alfred Ave, Smithers, BC, Canada
| | - S Li
- Fisheries and Oceans Canada, Pacific Biological Station, Hammond Bay Rd, Nanaimo, BC, Canada
| | - K H Kaukinen
- Fisheries and Oceans Canada, Pacific Biological Station, Hammond Bay Rd, Nanaimo, BC, Canada
| | - A J Danylchuk
- Department of Environmental Conservation, University of Massachusetts Amherst, Holdsworth Way, Amherst, MA, USA
| | - S J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, Colonel By Dr., Ottawa, ON, Canada
| |
Collapse
|
2
|
Braden LM, Barker DE, Koop BF, Jones SRM. Differential modulation of resistance biomarkers in skin of juvenile and mature pink salmon, Oncorhynchus gorbuscha by the salmon louse, Lepeophtheirus salmonis. FISH & SHELLFISH IMMUNOLOGY 2015; 47:7-14. [PMID: 26272636 DOI: 10.1016/j.fsi.2015.08.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 07/29/2015] [Accepted: 08/07/2015] [Indexed: 06/04/2023]
Abstract
Juvenile pink salmon larger than 0.7 g reject the sea louse, Lepeophtheirus salmonis, and are considered resistant to the infection. Robust innate defense responses in the skin contribute to the observed resistance. In contrast adult pink salmon captured at sea or shortly before spawning carry large numbers of the parasite, suggesting inability to control the infection. The purpose of this research is to better understand these apparently contradictory conclusions by comparing a suite of genetic and cellular markers of resistance to L. salmonis in the skin of juvenile and mature pink salmon. The expression of major histocompatibility factor II, C-reactive protein, interleukin-1β, interleukin-8 and cyclooxygenase-2 was down-regulated in mature but not juvenile pink salmon. Similarly, skin at the site of parasite attachment in juvenile salmon was highly populated with MHIIβ(+) and IL-1β(+) cells that were either absent, or at reduced levels at similar sites in mature salmon. In addition, mucocyte density was relatively low in the skin of mature salmon, irrespective of louse infection. In juveniles, the higher mucocyte density decreased following louse attachment. We show that in mature pink salmon, genetic and histological responses in skin are depressed and speculate that salmonid defense against L. salmonis is modulated by maturation.
Collapse
Affiliation(s)
- Laura M Braden
- Department of Biology, University of Victoria, Victoria, B.C., V8W 3N5, Canada
| | - Duane E Barker
- Fisheries & Aquaculture Department, Vancouver Island University, Nanaimo, B.C., V9R 5S5, Canada
| | - Ben F Koop
- Department of Biology, University of Victoria, Victoria, B.C., V8W 3N5, Canada
| | - Simon R M Jones
- Department of Biology, University of Victoria, Victoria, B.C., V8W 3N5, Canada; Fisheries and Ocean Canada, Pacific Biological Station, Nanaimo, B.C., V9T 6N7, Canada.
| |
Collapse
|
3
|
Shelley LK, Osachoff HL, van Aggelen GC, Ross PS, Kennedy CJ. Alteration of immune function endpoints and differential expression of estrogen receptor isoforms in leukocytes from 17β-estradiol exposed rainbow trout (Oncorhynchus mykiss). Gen Comp Endocrinol 2013; 180:24-32. [PMID: 23036733 DOI: 10.1016/j.ygcen.2012.09.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 09/02/2012] [Accepted: 09/07/2012] [Indexed: 10/27/2022]
Abstract
While the endocrine system is known to modulate immune function in vertebrates, the role of 17β-estradiol (E2) in cellular immune function of teleosts is poorly understood. The cellular and molecular responses of juvenile rainbow trout (Oncorhynchus mykiss) to E2 treatment were evaluated by exposing fish to 0.47±0.02μg/L E2 (mean±SEM) for either 2 or 7d, with a subsequent 14d recovery period. After 2 and 7d of exposure to E2, hematocrit was significantly lower than in control fish. Lipopolysaccharide-induced lymphocyte proliferation was elevated on day 2 and concanavalin A-induced lymphocyte proliferation was reduced following 7d of E2 exposure. Four estrogen receptor (ER) transcripts were identified in purified trout head kidney leukocytes (HKL) and peripheral blood leukocytes (PBL). While the mRNA abundance of ERβ1 and ERβ2 was unaffected by treatment, ERα1 was up-regulated in HKL and PBL following 7d of E2 exposure. ERα2 was up-regulated in HKL after 7d of E2 exposure, but down-regulated in PBL after 2 and 7d of treatment. All parameters that were altered during the E2 exposure period returned to baseline levels following the recovery period. This study reports the presence of the full repertoire of ERs in purified HKL for the first time, and demonstrates that ERα transcript abundance in leukocytes can be regulated by waterborne E2 exposure. It also demonstrated that physiologically-relevant concentrations of E2 can modulate several immune functions in salmonids, which may have widespread implications for xenoestrogen-associated immunotoxicity in feral fish populations inhabiting contaminated aquatic environments.
Collapse
Affiliation(s)
- Lesley K Shelley
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | | | | | | | | |
Collapse
|
4
|
Li M, Leatherland JF, Woo PTK. Cortisol and dexamethasone increase the in vitro multiplication of the haemoflagellate, Cryptobia salmositica, possibly by interaction with a glucocorticoid receptor-like protein. Int J Parasitol 2012; 43:353-60. [PMID: 23262305 DOI: 10.1016/j.ijpara.2012.11.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 11/19/2012] [Accepted: 11/21/2012] [Indexed: 11/17/2022]
Abstract
Cryptobia salmositica is a pathogenic haemoflagellate of Pacific salmon, Oncorhynchus spp., on the west coast of North America. The in vitro multiplication of the parasite was significantly enhanced by the addition of cortisol (within a range consistent with physiological levels in salmonid fishes; 10-50 ng ml(-1)) to the culture medium (MEM supplemented with FBS). However, higher cortisol concentrations (100 and 200 ng ml(-1)) either had no enhancing effects or resulted in lower replication rates compared with the controls. The synthetic glucocorticoid, dexamethasone (Dex), also stimulated the replication of the parasite and mifepristone (RU486), a synthetic steroid that has glucocorticoid receptor (GR) antagonist properties, inhibited the stimulatory actions of both cortisol and Dex, when added to the medium at a concentration of 100 ng ml(-1) co-culture with cortisol or Dex. Furthermore, the dose-dependent effects of glucocorticoids (cortisol and Dex) on the multiplication of the haemoflagellate were correlated with the initial size of the inocula. The study revealed a novel relationship between the parasite and its host, in which the host's cortisol is used by the parasite to enhance its replication. Also, since C. salmositica responds to both native and synthetic glucocorticoids and to the GR antagonist, RU486, and exhibits a biphasic (hormetic) response to the amount of cortisol in the medium, we propose that the glucocorticoid exerts its effects via an interaction with GR-like proteins in C. salmositica that are functionally similar to those present in vertebrate cells.
Collapse
Affiliation(s)
- Mao Li
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | | | | |
Collapse
|
5
|
Shelley LK, Ross PS, Miller KM, Kaukinen KH, Kennedy CJ. Toxicity of atrazine and nonylphenol in juvenile rainbow trout (Oncorhynchus mykiss): effects on general health, disease susceptibility and gene expression. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2012; 124-125:217-226. [PMID: 22982499 DOI: 10.1016/j.aquatox.2012.08.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 08/02/2012] [Accepted: 08/02/2012] [Indexed: 06/01/2023]
Abstract
Atrazine (ATZ) and nonylphenol (NP) are commonly identified contaminants in aquatic habitats; however, few studies have considered the impact of these endocrine disrupters on immune function and resistance to disease. This study examined the immunotoxicological effects of ATZ and NP at multiple levels of biological organization. Juvenile rainbow trout (Oncorhynchus mykiss) were exposed to a solvent control (0.00625%, v/v anhydrous ethanol), or sub-lethal concentrations of ATZ (59 μg/L and 555 μg/L) or NP (2.3 μg/L or 18 μg/L) for 4d. At the end of exposure, fish were assessed for a number of physiological endpoints, including a host resistance challenge, and liver gene expression was assessed using a salmonid microarray (cGRASP, 32K version 1). While the low ATZ and low NP treatments had no measurable effects on the physiological endpoints measured, fish exposed to the high ATZ concentration (555 μg/L) exhibited significantly elevated plasma cortisol, a decrease in SSI, and decreased lymphocytes and increased monocytes in peripheral blood, with suppression of early immune system processes apparent at the molecular level. In contrast, fish exposed to the high NP concentration (18 μg/L) showed physiological (e.g. significantly elevated LSI) and gene expression changes (e.g. induction of vitellogenin) consistent with estrogenic effects, as well as decreased lymphocytes in the peripheral blood and more limited alterations in immune system related pathways in the liver transcriptome. Fish exposed to high ATZ or NP concentrations incurred higher mortality than control fish following a disease challenge with Listonella anguillarum, while fish exposed to the lower concentrations were unaffected. Microarray analysis of the liver transcriptome revealed a total of 211 unique, annotated differentially regulated genes (DRGs) following high ATZ exposure and 299 DRGs following high NP exposure. Functional (enrichment) analysis revealed effects on immune system function, metabolism, oxygen homeostasis, cell cycle, DNA damage, and other processes affected by ATZ or NP exposure. Overall, this study provides evidence at multiple levels of biological organization that both ATZ and NP are immunotoxic at sub-lethal concentrations and highlights the potential risk posed by these chemicals to wild fish populations.
Collapse
Affiliation(s)
- Lesley K Shelley
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | | | | | | | | |
Collapse
|
6
|
Abstract
While intensive aquaculture has and will continue to supply the ever growing population with highly nutritious protein, it also comes with problems which include more frequent outbreaks of diseases in fish farms and transmission of diseases between farmed and wild fish. We have selected four Phyla of economically important fish parasites for our present discussion-a haemoflagellate (Cryptobia salmositica), a microsporidian, (Loma salmonae), a monogenean (Gyrodactylus salaries) and two copepods (Lepeophtheirus salmonis, Caligus rogercresseyi). This review consists of two parts with a brief description of each parasite and its biology related to transmission, followed by discussions on epizootic outbreaks in both wild and farmed fish, interactions between wild and farmed fish, and disease prevention and control.
Collapse
Affiliation(s)
- F C Guo
- Novartis Animal Health Canada Inc., Aqua Heath Business, Victoria, PE, C0A 2G0, Canada.
| | | |
Collapse
|
7
|
Morley NJ. Environmental risk and toxicology of human and veterinary waste pharmaceutical exposure to wild aquatic host-parasite relationships. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2009; 27:161-175. [PMID: 21783935 DOI: 10.1016/j.etap.2008.11.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2008] [Revised: 11/09/2008] [Accepted: 11/12/2008] [Indexed: 05/31/2023]
Abstract
Pollution of the aquatic environment by human and veterinary waste pharmaceuticals is an increasing area of concern but little is known about their ecotoxicological effects on wildlife. In particular the interactions between pharmaceuticals and natural stressors of aquatic communities remains to be elucidated. A common natural stressor of freshwater and marine organisms are protozoan and metazoan parasites, which can have significant effects on host physiology and population structure, especially under the influence of many traditional kinds of toxic pollutants. However, little is known about the effects of waste pharmaceuticals to host-parasite dynamics. In order to assess the risk waste pharmaceuticals pose to aquatic wildlife it has been suggested the use of toxicological data derived from mammals during the product development of pharmaceuticals may be useful for predicting toxic effects. An additional similar source of information is the extensive clinical studies undertaken with numerous classes of drugs against parasites of human and veterinary importance. These studies may form the basis of preliminary risk assessments to aquatic populations and their interactions with parasitic diseases in pharmaceutical-exposed habitats. The present article reviews the effects of the most common classes of pharmaceutical medicines to host-parasite relationships and assesses the risk they may pose to wild aquatic organisms. In addition the effects of pharmaceutical mixtures, the importance of sewage treatment, and the risk of developing resistant strains of parasites are also assessed.
Collapse
Affiliation(s)
- Neil J Morley
- School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK
| |
Collapse
|