1
|
Baiko D, Lisnerová M, Bartošová-Sojková P, Holzer AS, Blabolil P, Schabuss M, Fiala I. Solving the Myxidium rhodei (Myxozoa) puzzle: insights into its phylogeny and host specificity in Cypriniformes. Parasite 2024; 31:35. [PMID: 38949637 PMCID: PMC11216160 DOI: 10.1051/parasite/2024030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 05/16/2024] [Indexed: 07/02/2024] Open
Abstract
Myxidium rhodei Léger, 1905 (Cnidaria: Myxozoa) is a kidney-infecting myxosporean that was originally described from the European bitterling Rhodeus amarus. Subsequently, it has been documented based on spore morphology in more than 40 other cypriniform species, with the roach Rutilus rutilus being the most commonly reported host. This study introduces the first comprehensive data assessment of M. rhodei, conducted through morphological, ecological and molecular methods. The morphological and phylogenetic analyses of SSU rDNA sequences of Myxidium isolates obtained from European bitterling and roach did not support parasite conspecificity from these fish. In fact, the roach-infecting isolates represent three distinct parasite species. The first two, M. rutili n. sp. and M. rutilusi n. sp., are closely related cryptic species clustering with other myxosporeans in the freshwater urinary clade, sharing the same tissue tropism. The third one, M. batuevae n. sp., previously assigned to M. cf. rhodei, clustered in the hepatic biliary clade sister to bitterling-infecting M. rhodei. Our examination of diverse cypriniform fishes, coupled with molecular and morphological analyses, allowed us to untangle the cryptic species nature of M. rhodei and discover the existence of novel species. This underscores the largely undiscovered range of myxozoan diversity and highlights the need to incorporate sequence data in diagnosing novel species.
Collapse
Affiliation(s)
- Dariya Baiko
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences České Budějovice 37005 Czech Republic
- Faculty of Science, University of South Bohemia in České Budějovice České Budějovice 37005 Czech Republic
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University Oldenburg Oldenburg 26129 Germany
| | - Martina Lisnerová
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences České Budějovice 37005 Czech Republic
| | - Pavla Bartošová-Sojková
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences České Budějovice 37005 Czech Republic
| | - Astrid S. Holzer
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences České Budějovice 37005 Czech Republic
- Fish Health Division, University of Veterinary Medicine Vienna 1210 Austria
| | - Petr Blabolil
- Faculty of Science, University of South Bohemia in České Budějovice České Budějovice 37005 Czech Republic
- Institute of Hydrobiology, Biology Centre of the Czech Academy of Sciences České Budějovice 37005 Czech Republic
| | | | - Ivan Fiala
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences České Budějovice 37005 Czech Republic
- Faculty of Science, University of South Bohemia in České Budějovice České Budějovice 37005 Czech Republic
| |
Collapse
|
2
|
Saleh M, Hummel K, Schlosser S, Razzazi-Fazeli E, Bartholomew JL, Holzer A, Secombes CJ, El-Matbouli M. The myxozoans Myxobolus cerebralis and Tetracapsuloides bryosalmonae modulate rainbow trout immune responses: quantitative shotgun proteomics at the portals of entry after single and co-infections. Front Cell Infect Microbiol 2024; 14:1369615. [PMID: 38803570 PMCID: PMC11129561 DOI: 10.3389/fcimb.2024.1369615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 04/05/2024] [Indexed: 05/29/2024] Open
Abstract
Introduction Little is known about the proteomic changes at the portals of entry in rainbow trout after infection with the myxozoan parasites, Myxobolus cerebralis, and Tetracapsuloides bryosalmonae. Whirling disease (WD) is a severe disease of salmonids, caused by the myxosporean M. cerebralis, while, proliferative kidney disease (PKD) is caused by T. bryosalmonae, which instead belongs to the class Malacosporea. Climate change is providing more suitable conditions for myxozoan parasites lifecycle, posing a high risk to salmonid aquaculture and contributing to the decline of wild trout populations in North America and Europe. Therefore, the aim of this study was to provide the first proteomic profiles of the host in the search for evasion strategies during single and coinfection with M. cerebralis and T. bryosalmonae. Methods One group of fish was initially infected with M. cerebralis and another group with T. bryosalmonae. After 30 days, half of the fish in each group were co-infected with the other parasite. Using a quantitative proteomic approach, we investigated proteomic changes in the caudal fins and gills of rainbow trout before and after co-infection. Results In the caudal fins, 16 proteins were differentially regulated post exposure to M. cerebralis, whereas 27 proteins were differentially modulated in the gills of the infected rainbow trout post exposure to T. bryosalmonae. After co-infection, 4 proteins involved in parasite recognition and the regulation of host immune responses were differentially modulated between the groups in the caudal fin. In the gills, 11 proteins involved in parasite recognition and host immunity, including 4 myxozoan proteins predicted to be virulence factors, were differentially modulated. Discussion The results of this study increase our knowledge on rainbow trout co-infections by myxozoan parasites and rainbow trout immune responses against myxozoans at the portals of entry, supporting a better understanding of these host-parasite interactions.
Collapse
Affiliation(s)
- Mona Saleh
- Division of Fish Health, University of Veterinary Medicine, Vienna, Austria
| | - Karin Hummel
- VetCore, University of Veterinary Medicine, Vienna, Austria
| | | | | | - Jerri L. Bartholomew
- Department of Microbiology, Oregon State University, Corvallis, OR, United States
| | - Astrid Holzer
- Division of Fish Health, University of Veterinary Medicine, Vienna, Austria
| | - Christopher J. Secombes
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Scotland, United Kingdom
| | | |
Collapse
|
3
|
Akram N, El-Matbouli M, Saleh M. The Immune Response to the Myxozoan Parasite Myxobolus cerebralis in Salmonids: A Review on Whirling Disease. Int J Mol Sci 2023; 24:17392. [PMID: 38139218 PMCID: PMC10743445 DOI: 10.3390/ijms242417392] [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: 11/03/2023] [Revised: 12/03/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
Salmonids are affected by the economically significant whirling disease (WD) caused by the myxozoan parasite Myxobolus cerebralis. In the past, it was endemic to Eurasia, but it has now spread to different regions of North America, Europe, New Zealand, and South Africa. Among salmonids, rainbow trout is considered the most highly susceptible host. Upon entering to the host's body, the parasite invades the spine and cranium, resulting in whirling behaviour, a blackened tail, and destruction of cartilage. The disease is characterized by the infiltration of numerous inflammatory cells, primarily lymphocytes and macrophages, with the onset of fibrous tissue infiltration. Several efforts have been undertaken to investigate the role of various immune modulatory molecules and immune regulatory genes using advanced molecular methods including flow cytometry and transcriptional techniques. Investigation of the molecular and cellular responses, the role of STAT3 in Th17 cell differentiation, and the inhibitory actions of suppressors of cytokine signaling (SOCS) on interferons and interleukins, as well as the role of natural resistance-associated macrophage proteins (Nramp) in WD have significantly contributed to our understanding of the immune regulation mechanism in salmonids against M. cerebralis. This review thoroughly highlights previous research and discusses potential future directions for understanding the molecular immune response of salmonids and the possible development of prophylactic approaches against WD.
Collapse
Affiliation(s)
| | | | - Mona Saleh
- Division of Fish Health, Department of Farm Animals and Veterinary Public Health, University of Veterinary Medicine, 1210 Vienna, Austria; (N.A.)
| |
Collapse
|
4
|
Baxa DV, Nehring RB. Effect of substrate on the proliferation of Myxobolus cerebralis in the mitochondrial lineages of the Tubifex tubifex host. Parasitol Res 2022; 121:2503-2516. [PMID: 35895112 PMCID: PMC9378325 DOI: 10.1007/s00436-022-07587-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 06/24/2022] [Indexed: 10/31/2022]
Abstract
The study goal was to examine the effects of sand and mud on the propagation of Myxobolus cerebralis, the whirling disease agent, in four mitochondrial 16S ribosomal DNA lineages (I, III, V, VI) of its oligochaete host, Tubifex tubifex (Tt). In all the lineage groups held continuously in either substrate (non-shifted) or transferred from sand to mud (shifted), substrate influenced parasite proliferation only in lineage III. Sporogenesis and release of triactinomyxon spores (TAMs) were more prevalent in lineage III Tt in mud compared to sand. Low-infection prevalence and lack of parasite development in lineage I is associated with the greater number of resistant worms and were not affected by substrate type. Substrate did not impact Tt from lineages V and VI that failed to develop any parasite stages in either substrate even after shifting from sand to mud. The relationship between the microbial community in the substrate and parasite proliferation in lineage III was described but not analyzed due to small sample size. Substrate-associated bacteria were hypothesized as essential dietary source for the oligochaete host feeding selectively on fine (mud)-microflora. Progeny was produced by all lineage groups shifted to mud with disparate survival profiles in lineage V and VI and high mortalities in lineage III. Our study demonstrates that substrate type can alter parasite proliferation in lineage III. Conversely, parasite development and infectivity were not altered in lineage V and VI that are refractory to the parasite nor among the more resistant phenotypes (I), regardless of substrate type.
Collapse
Affiliation(s)
- Dolores V Baxa
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA. .,Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA.
| | - R Barry Nehring
- Colorado Division of Parks and Wildlife, 2300 South Townsend Avenue, Montrose, CO, 81401, USA
| |
Collapse
|
5
|
Holzer AS, Piazzon MC, Barrett D, Bartholomew JL, Sitjà-Bobadilla A. To React or Not to React: The Dilemma of Fish Immune Systems Facing Myxozoan Infections. Front Immunol 2021; 12:734238. [PMID: 34603313 PMCID: PMC8481699 DOI: 10.3389/fimmu.2021.734238] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/01/2021] [Indexed: 11/13/2022] Open
Abstract
Myxozoans are microscopic, metazoan, obligate parasites, belonging to the phylum Cnidaria. In contrast to the free-living lifestyle of most members of this taxon, myxozoans have complex life cycles alternating between vertebrate and invertebrate hosts. Vertebrate hosts are primarily fish, although they are also reported from amphibians, reptiles, trematodes, mollusks, birds and mammals. Invertebrate hosts include annelids and bryozoans. Most myxozoans are not overtly pathogenic to fish hosts, but some are responsible for severe economic losses in fisheries and aquaculture. In both scenarios, the interaction between the parasite and the host immune system is key to explain such different outcomes of this relationship. Innate immune responses contribute to the resistance of certain fish strains and species, and the absence or low levels of some innate and regulatory factors explain the high pathogenicity of some infections. In many cases, immune evasion explains the absence of a host response and allows the parasite to proliferate covertly during the first stages of the infection. In some infections, the lack of an appropriate regulatory response results in an excessive inflammatory response, causing immunopathological consequences that are worse than inflicted by the parasite itself. This review will update the available information about the immune responses against Myxozoa, with special focus on T and B lymphocyte and immunoglobulin responses, how these immune effectors are modulated by different biotic and abiotic factors, and on the mechanisms of immune evasion targeting specific immune effectors. The current and future design of control strategies for myxozoan diseases is based on understanding this myxozoan-fish interaction, and immune-based strategies such as improvement of innate and specific factors through diets and additives, host genetic selection, passive immunization and vaccination, are starting to be considered.
Collapse
Affiliation(s)
- Astrid S Holzer
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czechia
| | - M Carla Piazzon
- Fish Pathology Group, Institute of Aquaculture Torre de la Sal - Consejo Superior de Investigaciones Científicas (IATS-CSIC), Castellón, Spain
| | - Damien Barrett
- Department of Microbiology, Oregon State University, Corvallis, OR, United States
| | - Jerri L Bartholomew
- Department of Microbiology, Oregon State University, Corvallis, OR, United States
| | - Ariadna Sitjà-Bobadilla
- Fish Pathology Group, Institute of Aquaculture Torre de la Sal - Consejo Superior de Investigaciones Científicas (IATS-CSIC), Castellón, Spain
| |
Collapse
|
6
|
Myxozoan parasites vary in river herring according to life history stage and habitat. Parasitol Res 2021; 120:3709-3723. [PMID: 34599358 DOI: 10.1007/s00436-021-07329-y] [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: 07/09/2021] [Accepted: 09/23/2021] [Indexed: 10/20/2022]
Abstract
Anadromous river herring have declined in many parts of their range, leading to fisheries management efforts to help repopulate this species by improving connectivity of rivers and restoring populations by fish transfers. With data lacking on parasites in these species, this study sought to better understand myxozoans across various life stages and habitats in river herring populations in New Jersey, USA. We compared fish from riverine habitats during early-life growth and adults returning to spawn, marine-phase fish, and landlocked Alewife populations. Three myxozoan species were identified in young-of-the-year (YOY) anadromous river herring, including Kudoa clupeidae in the skeletal musculature, Myxobolus mauriensis in the rib cartilage, and an uncharacterized coelozoic myxozoan within the lumen of mesonephric tubules. In YOY river herring, Blueback Herring were 2 times more likely to be infected by K. clupeidae than Alewife (p = 0.019) and in the Maurice River, fish were 4 times more likely to be infected with M. mauriensis than fish from Great Egg Harbor River (p = 0.000) and 11 times more likely than the Delaware River (p = 0.001). Spawning adult river herring were infected with a previously undescribed myxozoan parasite infecting the kidney. Sequencing the 18S rDNA indicated this species is closely related to Ortholinea species. Myxobolus mauriensis and the Ortholinea-like species were absent from marine-phase river herring indicating that infections were linked to river environments occurring during early-life growth and spawning, respectively. No myxozoans were present in landlocked Alewife, showing that similar infections occurring in rivers were absent in lake environments in the region.
Collapse
|
7
|
Patrick CJ, Anderson KE, Brown BL, Hawkins CP, Metcalfe A, Saffarinia P, Siqueira T, Swan CM, Tonkin JD, Yuan LL. The application of metacommunity theory to the management of riverine ecosystems. WIRES. WATER 2021; 8:1-21. [PMID: 35874117 PMCID: PMC9301706 DOI: 10.1002/wat2.1557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
River managers strive to use the best available science to sustain biodiversity and ecosystem function. To achieve this goal requires consideration of processes at different scales. Metacommunity theory describes how multiple species from different communities potentially interact with local-scale environmental drivers to influence population dynamics and community structure. However, this body of knowledge has only rarely been used to inform management practices for river ecosystems. In this paper, we present a conceptual model outlining how the metacommunity processes of local niche sorting and dispersal can influence the outcomes of management interventions and provide a series of specific recommendations for applying these ideas as well as research needs. In all cases, we identify situations where traditional approaches to riverine management could be enhanced by incorporating an understanding of metacommunity dynamics. A common theme is developing guidelines for assessing the metacommunity context of a site or region, evaluating how that context may affect the desired outcome, and incorporating that understanding into the planning process and methods used. To maximize the effectiveness of management activities, scientists and resource managers should update the toolbox of approaches to riverine management to reflect theoretical advances in metacommunity ecology.
Collapse
Affiliation(s)
- Christopher J Patrick
- Department of Biological Sciences, Virginia Institute of Marine Science, College of William and Mary, 1370 Greate Rd., Gloucester Point, VA 23062
| | - Kurt E Anderson
- Department of Evolution, Ecology, and Organismal Biology, 900 University Ave., University of California, Riverside, CA, 92521, USA
| | - Brown L Brown
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24060, USA
| | - Charles P Hawkins
- Department of Watershed Sciences, Ecology Center, and National Aquatic Monitoring Center, Utah State University, Logan, Utah, USA
| | - Anya Metcalfe
- United States Geological Survey, Grand Canyon Monitoring and Research Center, 2255 North Gemini Drive, Flagstaff, AZ 86001
| | - Parsa Saffarinia
- Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, CA, 95616, USA
| | - Tadeu Siqueira
- Institute of Biosciences, São Paulo State University (Unesp), Av. 24A 1515, Rio Claro, São Paulo 13506-900 Brazil
| | | | - Jonathan D Tonkin
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Lester L Yuan
- United States Environmental Protection Agency - Office of Water
| |
Collapse
|
8
|
Cortez MH, Duffy MA. The Context-Dependent Effects of Host Competence, Competition, and Pathogen Transmission Mode on Disease Prevalence. Am Nat 2021; 198:179-194. [PMID: 34260871 DOI: 10.1086/715110] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractBiodiversity in communities is changing globally, including the gain and loss of host species in host-pathogen communities. Increased host diversity can cause infection prevalence in a focal host to increase (amplification) or decrease (dilution). However, it is unclear what general rules govern the context-dependent effects, in part because theories for pathogens with different transmission modes have developed largely independently. Using a two-host model, we explore how the pathogen transmission mode and characteristics of a second host (disease competence and competitive ability) influence disease prevalence in a focal host. Our work shows how the theories for pathogens with environmental transmission, density-dependent direct transmission, and frequency-dependent direct transmission can be unified. Our work also identifies general rules about how host and pathogen characteristics affect amplification/dilution. For example, higher-competence hosts promote amplification, unless they are strong interspecific competitors; strong interspecific competitors promote dilution, unless they are large sources of new infections; and dilution occurs under frequency-dependent direct transmission more than density-dependent direct transmission, unless interspecific host competition is sufficiently strong. Our work helps explain how the characteristics of the pathogen and a second host affect disease prevalence in a focal host.
Collapse
|
9
|
Cortez MH. Using sensitivity analysis to identify factors promoting higher versus lower infection prevalence in multi-host communities. J Theor Biol 2021; 526:110766. [PMID: 34019849 DOI: 10.1016/j.jtbi.2021.110766] [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: 12/22/2020] [Revised: 05/04/2021] [Accepted: 05/12/2021] [Indexed: 10/21/2022]
Abstract
Relationships between host species richness and levels of disease in a focal host are likely to be context-dependent, depending on the characteristics of which particular host species are present in a community. I use a multi-host epidemiological model with environmental transmission to explore how the characteristics of the host species (e.g., competence and competitive ability), host density, and the pathogen transmission mechanism affect the proportion of infected individuals (i.e., infection prevalence) in a focal host. My sensitivity-based approach identifies the indirect pathways through which specific ecological and epidemiological processes affect focal host infection prevalence. This in turn yields predictions about the context-dependent rules governing whether increased host species richness increases (amplifies) or decreases (dilutes) infection prevalence in a focal host. For example, in many cases, amplification and dilution are predicted to occur when added host species are sources or sinks of infectious propagules, respectively. However, if the added host species have strong and asymmetric competitive effects on resident host species, then amplification and dilution are predicted to occur when the added host species have stronger competitive effects on resident host species that are sources or sinks of infectious propagules, respectively. My results also predict that greater dilution and less amplification is more likely to occur under frequency-dependent direct transmission than density-dependent direct transmission when (i) the added hosts have lower competence than resident host species and (ii) interspecific competition between the added host species and resident host species is lower; the opposite conditions promote greater amplification and less dilution under frequency-dependent direct transmission. This work helps identify and explain the mechanisms shaping the context-dependent relationships between host species richness and disease in multi-host communities.
Collapse
Affiliation(s)
- Michael H Cortez
- Depart of Biological Science, Florida State University, Tallahassee, FL 32306, United States.
| |
Collapse
|
10
|
Shivam S, El-Matbouli M, Kumar G. Development of Fish Parasite Vaccines in the OMICs Era: Progress and Opportunities. Vaccines (Basel) 2021; 9:179. [PMID: 33672552 PMCID: PMC7923790 DOI: 10.3390/vaccines9020179] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 02/07/2023] Open
Abstract
Globally, parasites are increasingly being recognized as catastrophic agents in both aquaculture sector and in the wild aquatic habitats leading to an estimated annual loss between 1.05 billion and 9.58 billion USD. The currently available therapeutic and control measures are accompanied by many limitations. Hence, vaccines are recommended as the "only green and effective solution" to address these concerns and protect fish from pathogens. However, vaccine development warrants a better understanding of host-parasite interaction and parasite biology. Currently, only one commercial parasite vaccine is available against the ectoparasite sea lice. Additionally, only a few trials have reported potential vaccine candidates against endoparasites. Transcriptome, genome, and proteomic data at present are available only for a limited number of aquatic parasites. Omics-based interventions can be significant in the identification of suitable vaccine candidates, finally leading to the development of multivalent vaccines for significant protection against parasitic infections in fish. The present review highlights the progress in the immunobiology of pathogenic parasites and the prospects of vaccine development. Finally, an approach for developing a multivalent vaccine for parasitic diseases is presented. Data sources to prepare this review included Pubmed, google scholar, official reports, and websites.
Collapse
Affiliation(s)
- Saloni Shivam
- Clinical Division of Fish Medicine, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (S.S.); (M.E.-M.)
- Central Marine Fisheries Research Institute, Karwar 581301, India
| | - Mansour El-Matbouli
- Clinical Division of Fish Medicine, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (S.S.); (M.E.-M.)
| | - Gokhlesh Kumar
- Clinical Division of Fish Medicine, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (S.S.); (M.E.-M.)
| |
Collapse
|
11
|
Ganeva VO, Korytář T, Pecková H, McGurk C, Mullins J, Yanes-Roca C, Gela D, Lepič P, Policar T, Holzer AS. Natural Feed Additives Modulate Immunity and Mitigate Infection with Sphaerospora molnari (Myxozoa:Cnidaria) in Common Carp: A Pilot Study. Pathogens 2020; 9:pathogens9121013. [PMID: 33276442 PMCID: PMC7761334 DOI: 10.3390/pathogens9121013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/20/2020] [Accepted: 11/28/2020] [Indexed: 01/06/2023] Open
Abstract
Myxozoans are a diverse group of cnidarian parasites, including important pathogens in different aquaculture species, without effective legalized treatments for fish destined for human consumption. We tested the effect of natural feed additives on immune parameters of common carp and in the course of a controlled laboratory infection with the myxozoan Sphaerospora molnari. Carp were fed a base diet enriched with 0.5% curcumin or 0.12% of a multi-strain yeast fraction, before intraperitoneal injection with blood stages of S. molnari. We demonstrate the impact of these treatments on respiratory burst, phagocytosis, nitric oxide production, adaptive IgM+ B cell responses, S. molnari-specific antibody titers, and on parasite numbers. Both experimental diets enriched B cell populations prior to infection and postponed initial parasite proliferation in the blood. Curcumin-fed fish showed a decrease in reactive oxygen species, nitric oxide production and B cell density at late-stage infection, likely due to its anti-inflammatory properties, favoring parasite propagation. In contrast, multi-strain yeast fraction (MsYF)-fed fish harbored the highest S. molnari-specific antibody titer, in combination with the overall lowest parasite numbers. The results demonstrate that yeast products can be highly beneficial for the outcome of myxozoan infections and could be used as effective feed additives in aquaculture.
Collapse
Affiliation(s)
- Vyara O. Ganeva
- Biology Center of the Czech Academy of Sciences, Institute of Parasitology, 37005 České Budějovice, Czech Republic; (V.O.G.); (T.K.); (H.P.)
| | - Tomáš Korytář
- Biology Center of the Czech Academy of Sciences, Institute of Parasitology, 37005 České Budějovice, Czech Republic; (V.O.G.); (T.K.); (H.P.)
- South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia, 37005 České Budějovice, Czech Republic; (C.Y.-R.); (D.G.); (P.L.); (T.P.)
| | - Hana Pecková
- Biology Center of the Czech Academy of Sciences, Institute of Parasitology, 37005 České Budějovice, Czech Republic; (V.O.G.); (T.K.); (H.P.)
| | - Charles McGurk
- Skretting Aquaculture Research Centre, 4016 Stavanger, Norway; (C.M.); (J.M.)
| | - Julia Mullins
- Skretting Aquaculture Research Centre, 4016 Stavanger, Norway; (C.M.); (J.M.)
| | - Carlos Yanes-Roca
- South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia, 37005 České Budějovice, Czech Republic; (C.Y.-R.); (D.G.); (P.L.); (T.P.)
| | - David Gela
- South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia, 37005 České Budějovice, Czech Republic; (C.Y.-R.); (D.G.); (P.L.); (T.P.)
| | - Pavel Lepič
- South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia, 37005 České Budějovice, Czech Republic; (C.Y.-R.); (D.G.); (P.L.); (T.P.)
| | - Tomáš Policar
- South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia, 37005 České Budějovice, Czech Republic; (C.Y.-R.); (D.G.); (P.L.); (T.P.)
| | - Astrid S. Holzer
- Biology Center of the Czech Academy of Sciences, Institute of Parasitology, 37005 České Budějovice, Czech Republic; (V.O.G.); (T.K.); (H.P.)
- Correspondence: ; Tel.: +420-38777-5452
| |
Collapse
|
12
|
Saleh M, Friedl A, Srivastava M, Secombes CJ, El-Matbouli M. Modulation of local and systemic immune responses in brown trout (Salmo trutta) following exposure to Myxobolus cerebralis. FISH & SHELLFISH IMMUNOLOGY 2020; 106:844-851. [PMID: 32891791 DOI: 10.1016/j.fsi.2020.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/27/2020] [Accepted: 09/03/2020] [Indexed: 06/11/2023]
Abstract
Myxobolus cerebralis, the etiological agent of Whirling Disease (WD), is a freshwater myxozoan parasite with considerable economic and ecological relevance for salmonids. There are differences in disease susceptibility between species and strains of salmonids. Recently, we have reported that the suppressor of cytokine signaling SOCS1 and SOCS3 are key in modulating rainbow trout (Oncorhynchus mykiss) immune responses and that resistant fish apparently exhibit effective Th17 cell response after exposure to M. cerebralis. It is unclear whether such molecules and pathways are also involved in the immune response of M. cerebralis infected brown trout (Salmo trutta). Hence, this study aimed to explore their role during immune modulation in infected brown trout, which is considered resistant to this parasite. Fish were exposed to the triactinomyxon (TAM) stages of M. cerebralis and quantitative real-time PCR (RT-qPCR) was carried out to examine local (caudal fin) and systemic (head kidney, spleen) immune transcriptional changes associated with WD over time in infected and control fish. All of the immune genes in the three tissues studied were differentially expressed in infected fish at multiple time points. Brown trout reduced the parasite load and demonstrated effective immune responses, likely by keeping pro-inflammatory and anti-inflammatory cytokines in balance whilst stimulating efficient Th17-mediated immunity. This study increases knowledge on the brown trout immune response to M. cerebralis and helps us to understand the underlying mechanisms of WD resistance.
Collapse
Affiliation(s)
- Mona Saleh
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Austria.
| | - Adina Friedl
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Austria.
| | - Mitaly Srivastava
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Austria.
| | - Christopher J Secombes
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Scotland, UK.
| | - Mansour El-Matbouli
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Austria.
| |
Collapse
|
13
|
Picard-Sánchez A, Estensoro I, Perdiguero P, Del Pozo R, Tafalla C, Piazzon MC, Sitjà-Bobadilla A. Passive Immunization Delays Disease Outcome in Gilthead Sea Bream Infected With Enteromyxum leei (Myxozoa), Despite the Moderate Changes in IgM and IgT Repertoire. Front Immunol 2020; 11:581361. [PMID: 33013935 PMCID: PMC7516018 DOI: 10.3389/fimmu.2020.581361] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 08/17/2020] [Indexed: 12/16/2022] Open
Abstract
Passive immunization constitutes an emerging field of interest in aquaculture, particularly with the restrictions for antibiotic use. Enteromyxum leei is a myxozoan intestinal parasite that invades the paracellular space of the intestinal epithelium, producing a slow-progressing disease, leading to anorexia, cachexia and mortalities. We have previously demonstrated that gilthead sea bream (GSB, Sparus aurata) that survive E. leei infection become resistant upon re-exposure, and this resistance is directly related to the presence of high levels of specific IgM in serum. Thus, the current work was aimed to determine if passive immunization could help to prevent enteromyxosis in GSB and to study in detail the nature of these protective antibodies. Serum from a pool of resistant (SUR) or naïve (NAI) animals was intracoelomically injected 24 h prior to the E. leei-effluent challenge and at 9 days post-challenge (dpc). Effluent challenge lasted for 23 days, and then the injected groups were allocated in separate tanks with clean water. A non-lethal parasite diagnosis was performed at 56 dpc. At the final sampling (100 dpc), blood, serum and tissues were collected for histology, molecular diagnosis and the detection of circulating antibodies. In parallel, we performed an immunoglobulin repertoire analysis of the fish generating SUR and NAI sera. The results showed that, fish injected with parasite-specific antibodies (spAbs) became infected with the parasite, but showed lower disease signs and intensity of infection than the other groups, indicating a later establishment of the parasite. Repertoire analysis revealed that E. leei induced a polyclonal expansion of diverse IgM and IgT subsets that could be in part an evasion strategy of the parasite. Nonetheless, GSB was able to produce sufficient levels of parasite-spAbs to avoid re-infection of surviving animals and confer certain degree of protection upon passive transfer of antibodies. These results highlight the crucial role of spAb responses against E. leei and set the basis for the development of effective treatment or prophylactic methods for aquaculture.
Collapse
Affiliation(s)
- Amparo Picard-Sánchez
- Fish Pathology Group, Institute of Aquaculture Torre de la Sal (IATS-CSIC), Castellón, Spain
| | - Itziar Estensoro
- Fish Pathology Group, Institute of Aquaculture Torre de la Sal (IATS-CSIC), Castellón, Spain
| | | | - Raquel Del Pozo
- Fish Pathology Group, Institute of Aquaculture Torre de la Sal (IATS-CSIC), Castellón, Spain
| | | | - M Carla Piazzon
- Fish Pathology Group, Institute of Aquaculture Torre de la Sal (IATS-CSIC), Castellón, Spain
| | - Ariadna Sitjà-Bobadilla
- Fish Pathology Group, Institute of Aquaculture Torre de la Sal (IATS-CSIC), Castellón, Spain
| |
Collapse
|
14
|
STAT3/SOCS3 axis contributes to the outcome of salmonid whirling disease. PLoS One 2020; 15:e0234479. [PMID: 32542025 PMCID: PMC7295227 DOI: 10.1371/journal.pone.0234479] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 05/26/2020] [Indexed: 12/15/2022] Open
Abstract
There are differences in disease susceptibility to whirling disease (WD) among strains of rainbow trout. The North American strain Trout Lodge (TL) is highly susceptible, whereas the German Hofer (HO) strain is more resistant. The suppressor of cytokine signaling (SOCS) proteins are key in inhibiting cytokine signaling. Their role in modulating the immune response against whirling disease is not completely clear. This study aimed at investigating the transcriptional response of SOCS1 and SOCS3 genes to Myxobolus cerebralis along with that of several upstream regulators and immune response genes. M. cerebralis induced the expression of SOCS1, the IL-6-dependent SOCS3, the anti-inflammatory cytokine IL-10 and the Treg associated transcription factor FOXP3 in TL fish at multiple time points, which likely caused a restricted STAT1 and STAT3 activity affecting the Th17/Treg17 balance. The expression of SOCS1 and the IL-6-dependent SOCS3 was induced constraining the activation of STAT1 and STAT3 in TL fish, thereby causing Th17/Treg17 imbalance and leaving the fish unable to establish a protective immune response against M. cerebralis or control inflammatory reactions increasing susceptibility to WD. Conversely, in HO fish, the expression of SOCS1 and SOCS3 was restrained, whereas the expression of STAT1 and IL-23-mediated STAT3 was induced potentially enabling more controlled immune responses, accelerating parasite clearance and elevating resistance. The induced expression of STAT1 and IL-23-mediated STAT3 likely maintained a successful Th17/Treg17 balance and enabled fish to promote effective immune responses favouring resistance against WD. The results provide insights into the role of SOCS1 and SOCS3 in regulating the activation and magnitude of host immunity in rainbow trout, which may help us understand the mechanisms that underlie the variation in resistance to WD.
Collapse
|
15
|
Henneguyosis in gills of Metynnis hypsauchen: an Amazon freshwater fish. J Parasit Dis 2019; 44:213-220. [PMID: 32174727 DOI: 10.1007/s12639-019-01183-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 11/22/2019] [Indexed: 10/25/2022] Open
Abstract
This study describes aspects of infection caused by Myxozoa of the genus Henneguya sp. in gills of fish belonging to the species Metynnis hypsauchen. Two sampling were made in the Capim river, close to the Ribeira community, in the municipality of Ipixuna do Pará, State of Pará, Brazil, during the months of August 2018 and March 2019. The animals were captured and transported live to the Laboratório de Pesquisa Carlos Azevedo, at the Universidade Federal Rural da Amazônia (UFRA), in Belém, Pará, Brazil. The animals were examined, and after parasitism was confirmed, Differential Interference Contrast Microscopes were used, to evaluate the parasite spores. Ziehl-Neelsen stain techniques were used in histology. Necroscopic analyses of Metynnis hypsauchen specimens found parasites in 80% of the hosts (16/20), with whitish-colored cysts in the branchial filaments, containing mature spores of the genus Henneguya. The histopathological analysis indicated large areas with cystic lesions with associated ischemic necrosis. The descriptions from this study indicate that the parasite drastically compromises the host's respiratory system. Additionally, it is worth noting that parasite fauna studies of fishes in the Capim river are still a vast topic for research; this is the first record of infection by Henneguya sp. in Metynnis hypsauchen, captured in the Capim river in Ipixuna do Pará.
Collapse
|
16
|
Saleh M, Montero R, Kumar G, Sudhagar A, Friedl A, Köllner B, El-Matbouli M. Kinetics of local and systemic immune cell responses in whirling disease infection and resistance in rainbow trout. Parasit Vectors 2019; 12:249. [PMID: 31113489 PMCID: PMC6528198 DOI: 10.1186/s13071-019-3505-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 05/14/2019] [Indexed: 11/10/2022] Open
Abstract
Background Whirling disease (WD), caused by the myxozoan parasite Myxobolus cerebralis, is responsible for high mortalities in rainbow trout hatcheries and natural populations. To elucidate how resistant and susceptible rainbow trout strains respond to early invasion, a well-established model of WD was used to demonstrate the kinetics of local and systemic immune responses in two rainbow trout strains, the susceptible American Trout Lodge (TL) and the more resistant German Hofer strain (HO). Methods Parasite load and cellular immune responses were compared across several time points after M. cerebralis exposure to elucidate the kinetics of immune cells in resistant and susceptible rainbow trout in response to early invasion. In the course of the 20 days following exposure, leukocyte kinetics was monitored by flow cytometry in the caudal fin (CF), head kidney (HK) and spleen (SP). For the analysis of the leukocyte composition, cells were stained using a set of monoclonal antibodies with known specificity for distinct subpopulations of rainbow trout leukocytes. Results Experiments indicated general increases of CF, HK and SP myeloid cells, while decreases of B cells and T cells in the SP and HK were observed at several time points in the TL strain. On the other hand, in the HO strain, increases of T cells were dominant in CF, HK and SP at multiple time points. The differences between HO and TL were most distinct at 2, 4, 12 and 48 hours post-exposure (hpe) as well as at 4 days post-exposure (dpe), with the vast majority of innate immune response cells having higher values in the susceptible TL strain. Alteration of the leukocyte populations with augmented local cellular responses and excessive immune reactions likely lead to subsequent host tissue damage and supports parasite invasion and development in TL. Conclusions The findings of this study highlight the significance of effective local and systemic immune reaction and indicate proper activation of T lymphocytes critical for host resistance during M. cerebralis infection. The present study provides insights into the cellular basis of protective immune responses against M. cerebralis and can help us to elucidate the mechanisms underlying the variation in resistance to WD.
Collapse
Affiliation(s)
- Mona Saleh
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria.
| | - Ruth Montero
- Institute of Immunology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - Gokhlesh Kumar
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Arun Sudhagar
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Adina Friedl
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Bernd Köllner
- Institute of Immunology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - Mansour El-Matbouli
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| |
Collapse
|
17
|
Co-existence of Myxobolus spp. (Myxozoa) in gray mullet (Mugil cephalus) juveniles from the Mediterranean Sea. Parasitol Res 2018; 118:159-167. [DOI: 10.1007/s00436-018-6151-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 11/12/2018] [Indexed: 10/27/2022]
|
18
|
Schall MK, Blazer VS, Walsh HL, Smith GD, Wertz T, Wagner T. Spatial and temporal variability of myxozoan parasite, Myxobolus inornatus, prevalence in young of the year smallmouth bass in the Susquehanna River Basin, Pennsylvania. JOURNAL OF FISH DISEASES 2018; 41:1689-1700. [PMID: 30117566 DOI: 10.1111/jfd.12878] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/29/2018] [Accepted: 06/30/2018] [Indexed: 06/08/2023]
Abstract
A myxozoan parasite, Myxobolus inornatus, is one disease agent identified in young of the year (YOY) smallmouth bass in the Susquehanna River Basin, Pennsylvania. We investigated spatial and temporal variability in M. Inornatus prevalence across the Susquehanna River Basin and at several out-of-basin sites. We examined potential land use drivers of M. Inornatus prevalence including agricultural and developed land use. In 1,267 YOY smallmouth bass collected from 32 sites during 2013-2016, M. Inornatus was documented in 43.6% of samples. Among-site variability in parasite prevalence was greater than among-year variability. The effect of agricultural land use on M. Inornatus prevalence had a high probability of being positively correlated at multiple spatial scales (probability of positive effect > 0.80). The effect of developed land use on M. Inornatus prevalence had a relatively high probability of being negatively correlated at multiple spatial scales (probability of negative effect > 0.70). Our results suggest that land use practices could be related to M. Inornatus infection of smallmouth bass. Further study will be necessary to determine whether disease dynamics are a consequence of effects on the host, alterations of instream habitat mediating invertebrate host dynamics and/or survival and dispersal of the parasite infective stage.
Collapse
Affiliation(s)
- Megan K Schall
- Intercollege Graduate Degree Program in Ecology, Pennsylvania Cooperative Fish and Wildlife Research Unit, Pennsylvania State University, University Park, Pennsylvania
| | - Vicki S Blazer
- U.S. Geological Survey, Fish Health Branch, Leetown Science Center, Kearneysville, West Virginia
| | - Heather L Walsh
- West Virginia University Research Corporation, Morgantown, West Virginia
| | | | - Timothy Wertz
- Pennsylvania Department of Environmental Protection, Harrisburg, Pennsylvania
| | - Tyler Wagner
- U.S. Geological Survey, Pennsylvania Cooperative Fish and Wildlife Research Unit, Pennsylvania State University, University Park, Pennsylvania
| |
Collapse
|
19
|
Ellipsomyxa arariensis n. sp. (Myxozoa: Ceratomyxidae), a new myxozoan parasite of Pygocentrus nattereri Kner, 1858 (Teleostei: Characidae) and Pimelodus ornatus Kner, 1858 (Teleostei: Pimelodidae) from Marajó Island, in the Brazilian Amazon region. Parasitol Res 2018; 117:3537-3545. [DOI: 10.1007/s00436-018-6051-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/09/2018] [Indexed: 11/25/2022]
|
20
|
Blatchley Iii ER, Cullen JJ, Petri B, Bircher K, Welschmeyer N. The Biological Basis for Ballast Water Performance Standards: "Viable/Non-Viable" or "Live/Dead"? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:8075-8086. [PMID: 29927584 DOI: 10.1021/acs.est.8b00341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The shipping industry is critical to international commerce; however, contemporary shipping practices involve uptake and discharge of ballast water, which introduces the potential for transfer of nonindigenous, invasive species among geographically distinct habitats. To counteract this hazard, regulations for ballast water management have been implemented by the International Maritime Organization (IMO) and by regulatory agencies such as the United States Coast Guard (USCG). IMO and USCG discharge standards are numerically identical, but involve different definitions of treatment end points, which are based on fundamentally different biological assays for quantification of ballast water treatment effectiveness. Available assays for quantification of the responses of organisms in the 10-50 μm size range include vital stains based on fluorescein diacetate (FDA), sometimes used in combination with 5-chloromethylfluorescein diacetate (CMFDA), observations of motility, and the most probable number dilution culture method (MPN). The mechanisms and implications of these assays are discussed relative to the Type Approval process, which quantitatively evaluates compliance with ballast water discharge standards (BWDSs) under controlled shipboard and land-based tests. For antimicrobial processes that accomplish treatment by preventing subsequent replication of the target species, the FDA/CMFDA and MPN methods can yield dramatically different results. An important example of a treatment process that is affected by the choice of assay is ultraviolet (UV) irradiation. Results of laboratory and field experiments have demonstrated UV-based technologies to be effective for accomplishing the objectives of ballast water treatment (inactivation of cellular reproduction), when the MPN assay is used as the basis for evaluation. The FDA, CMFDA, motility, and MPN methods are subject to well recognized sources of error; however, the MPN method is based on a response that is consistent with the objectives of ballast water management as well as the mechanism of action of UV-based inactivation. Complementary assays are available for use in compliance testing; however, the development of relevant indicative tests remains as a research priority. Historical lessons learned from applications of vital stains (and other indirect methods) for quantification of microbial responses to UV irradiation in other settings also support the use of assays that provide a direct measure of growth and reproduction, such as MPN. Collectively, these observations point to the use of MPN assays as the standard for type testing, especially when UV-based treatment is employed.
Collapse
Affiliation(s)
- Ernest R Blatchley Iii
- Lyles School of Civil Engineering and Division of Environmental & Ecological Engineering , Purdue University , 550 Stadium Mall Drive , West Lafayette , Indiana 47907 , United States
| | - John J Cullen
- Department of Oceanography , Dalhousie University , P.O. Box 15000, Halifax , Nova Scotia B3H 4R2 , Canada
| | - Brian Petri
- Trojan Technologies , 3020 Gore Road , London , Ontario N5 V 4T7 , Canada
| | - Keith Bircher
- Calgon Carbon Corporation , 3000 GSK Drive , Moon Township , Pennsylvania 15108 , United States
| | - Nicholas Welschmeyer
- Moss Landing Marine Laboratories , 8272 Moss Landing Rd. , Moss Landing California 95039 , United States
| |
Collapse
|
21
|
Gupta A, Kaur H. 18S and 28S rDNA identity and phylogeny of two novel myxosporeans infecting gills of cyprinid carps inhabiting a cold water wetland in northern India. Microb Pathog 2018; 120:97-108. [DOI: 10.1016/j.micpath.2018.04.042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 04/16/2018] [Accepted: 04/23/2018] [Indexed: 10/17/2022]
|
22
|
Kotob MH, Kumar G, Saleh M, Gorgoglione B, Abdelzaher M, El-Matbouli M. Differential modulation of host immune genes in the kidney and cranium of the rainbow trout (Oncorhynchus mykiss) in response to Tetracapsuloides bryosalmonae and Myxobolus cerebralis co-infections. Parasit Vectors 2018; 11:326. [PMID: 29848363 PMCID: PMC5977764 DOI: 10.1186/s13071-018-2912-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 05/22/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Most of the studies on fish diseases focus on single infections, although in nature co-infections occur more often. The two freshwater myxozoan parasites of salmonids, having high economic and ecologic relevance are Tetracapsuloides bryosalmonae (Malacosporea), the etiological agent of proliferative kidney disease, and Myxobolus cerebralis (Myxosporea), the etiological agent of whirling disease. The present study aims to investigate immune modulation in rainbow trouts (Oncorhynchus mykiss) during single and co-infections by these parasites. METHODS Fish were initially infected with T. bryosalmonae (one group) and M. cerebralis (another group) separately. At 30 days post-exposure (dpe), both the single species infected groups were co-infected, respectively, with the other parasite. Posterior kidney and cartilage cranium samples were collected at 30, 60, 90 and 120 dpe and RT-qPCR was performed on them to assess the transcription of suppressors of cytokine signaling (SOCS) -1 and -3, Janus kinase-1 (JAK-1) and signal transducer and activator of transcription-3 (STAT-3) genes. RESULTS Kidney samples from the T. bryosalmonae-infected group showed upregulation of all immune genes tested between 60-120 dpe. Crania from the single M. cerebralis-infected group and the M. cerebralis and T. bryosalmonae co-infected group exhibited upregulation of SOCS-1 and JAK-1 between 60-120 dpe and SOCS-3 at 120 dpe. However, only in the single M. cerebralis-infected group, was a statistically significant expression of STAT-3 observed at 30 and 60 dpe. CONCLUSIONS The results of this study indicate that both T. bryosalmonae and M. cerebralis induce overexpression of SOCS-1 and SOCS-3 genes and modulate the host immune response during the development of parasite to cause immunosuppression.
Collapse
Affiliation(s)
- Mohamed H Kotob
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.,Department of Pathology, Faculty of Veterinary Medicine, Assiut University, Assiut, 71526, Egypt
| | - Gokhlesh Kumar
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Mona Saleh
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Bartolomeo Gorgoglione
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.,Department of Biological Sciences, Wright State University, Dayton, OH, 45435, USA
| | - Mahmoud Abdelzaher
- Department of Pathology, Faculty of Veterinary Medicine, Assiut University, Assiut, 71526, Egypt
| | - Mansour El-Matbouli
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.
| |
Collapse
|
23
|
Myxobolus okamurae sp. nov. (Myxosporea: Myxozoa) causing severe gill myxoboliosis in the cyprinid Labeo bata in a cold water wetland, Punjab (India). Microb Pathog 2018; 115:86-92. [DOI: 10.1016/j.micpath.2017.12.041] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 12/12/2017] [Accepted: 12/14/2017] [Indexed: 11/18/2022]
|
24
|
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] [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.
Collapse
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
| |
Collapse
|
25
|
Gupta A, Kaur H. A new pathogen, Myxobolus holzerae (Myxosporea: Myxozoa) causing severe gill disease in an Indian major carp Labeo rohita in a cold water wetland, Punjab (India). Microb Pathog 2017; 111:244-251. [DOI: 10.1016/j.micpath.2017.08.044] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 08/20/2017] [Accepted: 08/30/2017] [Indexed: 10/18/2022]
|
26
|
Kotob MH, Gorgoglione B, Kumar G, Abdelzaher M, Saleh M, El-Matbouli M. The impact of Tetracapsuloides bryosalmonae and Myxobolus cerebralis co-infections on pathology in rainbow trout. Parasit Vectors 2017; 10:442. [PMID: 28946913 PMCID: PMC5613476 DOI: 10.1186/s13071-017-2347-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 08/28/2017] [Indexed: 11/25/2022] Open
Abstract
Background Myxozoan parasites pose emerging health issues for wild and farmed salmonid fish. Rainbow trout (Oncorhynchus mykiss) is a particularly susceptible species to Tetracapsuloides bryosalmonae (Malacosporea), the etiological agent of Proliferative Kidney Disease (PKD), and to Myxobolus cerebralis (Myxosporea), the etiological agent of Whirling Disease (WD). The objective of this study was to investigate the impact of myxozoan co-infections on the pathogenesis of PKD and WD in the rainbow trout. Methods Two groups of rainbow trout (96 fish each) were primarily infected with T. bryosalmonae and triactinomyxons of M. cerebralis; after 30 days half of the fish in each group were co-infected with these parasites vice versa and remaining half was continued as single infection. Mortalities and clinical signs were recorded at different time points. Histopathology and immunohistochemistry were performed to assess the extent of each infection and estimate the parasite burden between groups. Results Fish firstly infected with M. cerebralis and co-infected with T. bryosalmonae exhibited exacerbated pathological changes of both parasitic diseases and elicited a higher mortality rate. A higher kidney swelling index (grade 4) appeared together with more severe cartilage destruction and displacement, when compared to the pathological changes in fish upon single infections with T. bryosalmonae or M. cerebralis. Conversely, fish firstly infected with T. bryosalmonae and co-infected with M. cerebralis also exhibited typical pathological changes of both parasitic diseases, but with a lower mortality rate, similar as caused by the single T. bryosalmonae or M. cerebralis infection. WD clinical signs were milder, without skeletal deformities, while kidney swelling index was similar to single infection with T. bryosalmonae (grade 2 to 3). Conclusions In this study, a co-infection with myxozoan parasites was for the first time successfully achieved in the laboratory under controlled conditions. The impact of co-infections in concurrent myxozoan infections mainly depends on the primary pathogen infecting the host, which could alter the outcomes of the secondary pathogen infection. The primary M. cerebralis infection followed by T. bryosalmonae had a much more serious impact and elicited a synergistic interaction. Contrasting results were instead seen in rainbow trout primarily infected with T. bryosalmonae and then co-infected with M. cerebralis.
Collapse
Affiliation(s)
- Mohamed H Kotob
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.,Department of Pathology, Faculty of Veterinary Medicine, Assiut University, Assiut, 71526, Egypt
| | - Bartolomeo Gorgoglione
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.,Department of Biological Sciences, University of Toledo, Toledo, OH, 43606, USA
| | - Gokhlesh Kumar
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Mahmoud Abdelzaher
- Department of Pathology, Faculty of Veterinary Medicine, Assiut University, Assiut, 71526, Egypt
| | - Mona Saleh
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Mansour El-Matbouli
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.
| |
Collapse
|
27
|
Sarker S, Menanteau-Ledouble S, Kotob MH, El-Matbouli M. A RNAi-based therapeutic proof of concept targets salmonid whirling disease in vivo. PLoS One 2017; 12:e0178687. [PMID: 28575083 PMCID: PMC5456292 DOI: 10.1371/journal.pone.0178687] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 05/17/2017] [Indexed: 11/29/2022] Open
Abstract
Myxobolus cerebralis is a cnidarian-myxozoan parasite that causes salmonid whirling disease. M. cerebralis alternates between two hosts: (1) a vertebrate salmonid and (2) an invertebrate oligochaete, Tubifex tubifex. There is no successful treatment for salmonid whirling disease. MyxSP-1 is a M. cerebralis serine protease implicated in whirling disease pathogenesis. We hypothesized that short-interfering RNA (siRNA)-induced RNA interference (RNAi) can silence MyxSP-1 in the invertebrate host and abrogate the M. cerebralis life cycle. This would preclude whirling disease infection in the salmonid host. To test this hypothesis, we first developed a siRNA delivery protocol in T. tubifex. Second, we determined the effective dose for siRNA treatment of M. cerebralis-infected T. tubifex. M. cerebralis-infected T. tubifex were treated with different concentrations of MyxSP-1 or negative control siRNAs (1μM, 2μM, 5μM or 7μM) at 15°C for 24h, 48h, 72h and 96h, respectively. We monitored MyxSP-1 knockdown using real-time quantitative PCR (qPCR). siRNA treatment with MyxSP-1 siRNA at 2μM concentration for 24h at 15°C showed maximum significant MyxSP-1 knockdown in T. tubifex. Third, we determined the time points in the M. cerebralis life cycle in T. tubifex at which siRNA treatment was most effective. M. cerebralis-infected T. tubifex were treated with MyxSP-1 or negative control siRNAs (2μM concentration for 24h at 15°C) at 24 hours post-infection (24hpi), 48hpi, 72hpi, 96hpi, 1 month post-infection (1mpi), 2mpi and 3mpi, respectively. We observed that siRNA treatment of T. tubifex was most effective at 1mpi, 2mpi and 3mpi. Fourth, we immersed specific-pathogen-free rainbow trout fry in water inhabited by MyxSP-1 siRNA-treated T. tubifex (at 1mpi, 2mpi and 3mpi). The salmonids did not develop whirling disease and showed significant MyxSP-1 knockdown. We also observed long-term RNAi in T. tubifex. Together these results demonstrate a novel RNAi-based therapeutic proof of concept in vivo against salmonid whirling disease.
Collapse
Affiliation(s)
- Subhodeep Sarker
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
- Discipline of Pharmacology, School of Medical Sciences, Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia
- * E-mail: (SS); (ME-M)
| | - Simon Menanteau-Ledouble
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Mohamed H. Kotob
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
- Department of Pathology, Faculty of Veterinary Medicine, Assiut University, Asyut, Egypt
| | - Mansour El-Matbouli
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
- * E-mail: (SS); (ME-M)
| |
Collapse
|
28
|
Molnár K, Gibson DI, Majoros G, Székely C, Sándor D, Cech G. Malformations of the gill filaments of the ruffe Gymnocephalus cernuus (L.) (Pisces) caused by echinostomatid metacercariae. JOURNAL OF FISH DISEASES 2016; 39:1357-1367. [PMID: 27087601 DOI: 10.1111/jfd.12469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 01/13/2016] [Accepted: 01/14/2016] [Indexed: 06/05/2023]
Abstract
In parasite surveys of fishes from Lake Balaton and its tributaries in Hungary, infections with metacercariae of a species of the digenean genus Echinochasmus (Trematoda: Echinostomatidae) were found in seven species of fish. In ruffe, Gymnocephalus cernuus, malformations of the gill filaments apparently caused by these infections were observed. These malformations were in the form of bifurcations of the filaments at about their mid-length. At the point where the filaments bifurcate, an Echinochasmus metacercaria was always embedded in the cartilaginous ray of the gill filament. All specimens of the ruffe were found to be infected by these metacercariae, and each ruffe specimen was infected by 30-300 metacercariae. Such a bifurcation was found in all of the ruffe specimens, but, apart from these gill malformations, the metacercariae produced only local changes in the cartilage. In the other six infected fish species, only local signs were observed in the cartilage. Experimental infections of chicks with metacercariae resulted in the finding of the sexual adult (marita) of an unidentified species of Echinochasmus. ITS sequences of the adult and metacercaria corresponded with each other, and also with a cercaria isolated from a gravel snail (Lithoglyphus naticoides), with a 99.5-100% similarity.
Collapse
Affiliation(s)
- K Molnár
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary
| | - D I Gibson
- Department of Life Sciences, Natural History Museum, London, UK
| | - G Majoros
- Department of Parasitology and Zoology, Faculty of Veterinary Sciences, Szent István University, Budapest, Hungary
| | - C Székely
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary
| | - D Sándor
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary
| | - G Cech
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary.
| |
Collapse
|
29
|
Lovy J, Hutcheson JM. Myxobolus mauriensisn. sp. Infecting Rib Cartilage of Young-of-the-Year River Herring in New Jersey: Notes on Pathology, Prevalence, and Genetics. J Parasitol 2016; 102:419-28. [DOI: 10.1645/15-939] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Jan Lovy
- Office of Fish and Wildlife Health and Forensics, New Jersey Division of Fish and Wildlife, 605 Pequest Road, Oxford, New Jersey 07863
| | - Josette M. Hutcheson
- Office of Fish and Wildlife Health and Forensics, New Jersey Division of Fish and Wildlife, 605 Pequest Road, Oxford, New Jersey 07863
| |
Collapse
|
30
|
Kelley GO, Zagmutt-Vergara FJ, Leutenegger CM, Myklebust KA, Adkison MA, McDowell TS, Marty GD, Kahler AL, Bush AL, Gardner IA, Hedrick RP. Evaluation of Five Diagnostic Methods for the Detection and Quantification of Myxobolus Cerebralis. J Vet Diagn Invest 2016; 16:202-11. [PMID: 15152834 DOI: 10.1177/104063870401600305] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Diagnostic methods were used to identify and quantify Myxobolus cerebralis, a myxozoan parasite of salmonid fish. In this study, 7-week-old, pathogen-free rainbow trout ( Oncorhynchus mykiss) were experimentally infected with M. cerebralis and at 7 months postinfection were evaluated with 5 diagnostic assays: 1) pepsin–trypsin digest (PTD) to detect and enumerate spores found in cranial cartilage, 2) 2 different histopathology grading scales that provide a numerical score for severity of microscopic lesions in the head, 3) a conventional single-round polymerase chain reaction (PCR), 4) a nested PCR assay, and 5) a newly developed quantitative real-time TaqMan PCR. There were no significant differences ( P > 0.05) among the 5 diagnostic assays in distinguishing between experimentally infected and uninfected control fish. The 2 histopathology grading scales were highly correlated ( P < 0.001) for assessment of microscopic lesion severity. Quantification of parasite levels in cranial tissues using PTD and real-time TaqMan PCR was significantly correlated r = 0.540 ( P < 0.001). Lastly, 104 copies of the 18S rDNA gene are present in the M. cerebralis genome, a feature that makes this gene an excellent target for PCR-based diagnostic assays. Also, 2 copies of the insulin growth factor–I gene are found in the rainbow trout genome, whose detection can serve both as an internal quality control for amplifiable DNA and as a basis to quantify pathogen genome equivalents present in quantitative PCR assays.
Collapse
Affiliation(s)
- Garry O Kelley
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Abstract
The Myxozoa comprise over 2,000 species of microscopic obligate parasites that use both invertebrate and vertebrate hosts as part of their life cycle. Although the evolutionary origin of myxozoans has been elusive, a close relationship with cnidarians, a group that includes corals, sea anemones, jellyfish, and hydroids, is supported by some phylogenetic studies and the observation that the distinctive myxozoan structure, the polar capsule, is remarkably similar to the stinging structures (nematocysts) in cnidarians. To gain insight into the extreme evolutionary transition from a free-living cnidarian to a microscopic endoparasite, we analyzed genomic and transcriptomic assemblies from two distantly related myxozoan species, Kudoa iwatai and Myxobolus cerebralis, and compared these to the transcriptome and genome of the less reduced cnidarian parasite, Polypodium hydriforme. A phylogenomic analysis, using for the first time to our knowledge, a taxonomic sampling that represents the breadth of myxozoan diversity, including four newly generated myxozoan assemblies, confirms that myxozoans are cnidarians and are a sister taxon to P. hydriforme. Estimations of genome size reveal that myxozoans have one of the smallest reported animal genomes. Gene enrichment analyses show depletion of expressed genes in categories related to development, cell differentiation, and cell-cell communication. In addition, a search for candidate genes indicates that myxozoans lack key elements of signaling pathways and transcriptional factors important for multicellular development. Our results suggest that the degeneration of the myxozoan body plan from a free-living cnidarian to a microscopic parasitic cnidarian was accompanied by extreme reduction in genome size and gene content.
Collapse
|
32
|
Sarker S, Kallert DM, Hedrick RP, El-Matbouli M. Whirling disease revisited: pathogenesis, parasite biology and disease intervention. DISEASES OF AQUATIC ORGANISMS 2015; 114:155-175. [PMID: 25993890 DOI: 10.3354/dao02856] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Whirling disease (WD) is an ecologically and economically debilitating disease of rainbow trout Oncorhynchus mykiss caused by the actinosporean spores of the parasite Myxobolus cerebralis. M. cerebralis has a complex, 2-host life cycle alternating between salmonid fish and the oligochaete host Tubifex tubifex. The parasite alternates between 2 spore forms as transmission stages: an actinosporean triactinomyxon spore that is produced in the oligochaete host and a myxosporean spore that develops in the salmonid host. Waterborne triactinomyxon spores released from infected T. tubifex oligochaetes attach to the salmonid host by polar filament extrusion elicited by chemical (nucleoside) and mechanical (thigmotropy) stimuli-a process which is rapidly followed by active penetration of the sporoplasms into the fish epidermis. Upon penetration, sporoplasms multiply and migrate via peripheral nerves and the central nervous system to reach the cartilage where they form trophozoites which undergo further multiplication and subsequent sporogenesis. M. cerebralis myxospores are released into the aquatic environment when infected fish die and autolyse, or when they are consumed and excreted by predators. Myxospores released into the water are ingested by susceptible T. tubifex where they develop intercellularly in the intestine over a period of 3 mo through 4 developmental stages to give rise to mature actinospores. In this article, we review our current understanding of WD-the parasite and its alternate hosts, life cycle and development of the parasite in either host, disease distribution, susceptibility and resistance mechanisms in salmonid host and strategies involved in diagnosis, prevention and control of WD.
Collapse
Affiliation(s)
- Subhodeep Sarker
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
| | | | | | | |
Collapse
|
33
|
Parental genetic diversity of brown trout (Salmo trutta m. fario) brood stock affects offspring susceptibility to whirling disease. Parasit Vectors 2015; 8:141. [PMID: 25886048 PMCID: PMC4362631 DOI: 10.1186/s13071-015-0744-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 02/16/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Whirling disease, caused by the myxozoan parasite Myxobolus cerebralis, has high economical and ecological importance worldwide. Susceptibility to the disease varies considerably among salmonid species. In brown trout (Salmo trutta) the infection is usually subclinical with low mortality, which increases the risk of parasite dissemination, especially when farm fish are used for stocking natural habitats. The influence of intraspecific genetic differences (especially the level of homozygosity) on susceptibility is unknown. Therefore, we examined the possible correlations between parental genetic diversity and offspring susceptibility of brown trout stocks to whirling disease. METHODS Two brown trout brood stocks from a German and a Hungarian fish farm were genetically characterized using microsatellite and lineage-specific genetic markers. The individual inbreeding coefficient f and pairwise relatedness factor r were estimated based on eight microsatellite markers. Brood stock populations were divided into groups according to low and high f and r value estimates and subjected to selective fertilization. The offspring from these separate groups were exposed to M. cerebralis actinospores, and the infection prevalence and intensity was measured and statistically analysed. RESULTS The analysis of phylogeographic lineage heritage revealed high heterogeneity in the Hungarian brood stock since > 50% of individuals were Atlantic-Danubian hybrids, while only pure Atlantic-descending specimens were detected in the German population. Based on f msat and r msat estimations, classified non-inbred (NIB), inbred (IB) and a group of closely related fish (REL) were created. The susceptibility of their offspring varied considerably. Although there was no significant difference in the prevalence of M. cerebralis infection, the mean intensity of infection differed significantly between NIB and IB groups. In REL and IB groups, a high variability was observed in infection intensity. No external clinical signs were observed in the exposed brown trout groups. CONCLUSIONS Our findings indicate that the allelic diversity of brown trout brood stock may constitute a significant factor in disease susceptibility, i.e. the intensity of parasite infection in the subsequent generation.
Collapse
|
34
|
Barry Nehring B, Schisler G, Chiaramonte L, Horton A, Poole B. Assessment of the Long-Term Viability of the Myxospores of Myxobolus cerebralis as Determined by Production of the actinospores by Tubifex tubifex. JOURNAL OF AQUATIC ANIMAL HEALTH 2015; 27:50-56. [PMID: 26306333 DOI: 10.1080/08997659.2014.976671] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
While whirling disease was first observed in Rainbow Trout Oncorhynchus mykiss in 1893, the complete life cycle of Myxobolus cerebralis (Mc), the causative agent of the disease, was not understood until 1984, when it was shown to involve two obligate hosts, a salmonid fish and the aquatic oligochaete Tubifex tubifex (Tt). The viability of the triactinomyxon (TAM) actinospores produced by Tt has been well studied, and is known to be temperature dependent and measured in days and weeks. Assertions that Mc myxospores produced by infected fish remain viable for years or even decades were made during the mid-20th century, decades before the Mc life cycle was described. Moreover, the duration of myxospore viability has not been well studied since the life cycle was elucidated. In a series of time-delay treatments, we assessed the long-term viability of Mc myxospores by exposure to Mc-susceptible Tt oligochaetes and quantified TAM production. As the time delay between inoculation and incubation of Mc myxospores in sand and water and exposure to Tt oligochaetes increased, TAM production decreased exponentially. Production among the 15-d time-delay replicates was reduced 74.7% compared with the 0-d treatment. Likewise, total TAM production was reduced 94.5, 99.4, and 99.9%, respectively, in the 90-, 120-, and 180-d time-delay treatments. Linear regression analysis of our data and the absence of TAM production among replicates of Mc myxospores held at 5°C for 365 d prior to exposure to Mc-susceptible Tt oligochaetes indicate that the long-term viability of Mc myxospores is less than 1 year under the conditions of this study.
Collapse
|
35
|
Hurst CN, Bartholomew JL. Lack of Protection following Re-Exposure of Chinook Salmon to Ceratonova shasta (Myxozoa). JOURNAL OF AQUATIC ANIMAL HEALTH 2015; 27:20-24. [PMID: 25494609 DOI: 10.1080/08997659.2014.970716] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The recent identification of multiple genotypes of the salmonid parasite Ceratonova shasta with different virulence levels in Chinook Salmon Oncorhynchus tshawytscha suggests that it is possible to immunize fish against subsequent infection and disease. We hypothesized that exposure of Chinook Salmon to the less-virulent parasite genotype (II) prior to the more virulent parasite genotype (I) would decrease disease and/or result in fewer mature parasites compared with fish only infected with the more virulent genotype. To test this hypothesis, fish were challenged in a combination of field and laboratory exposures, and we measured infection prevalence, percent morbidity, and mature parasite production. Neither mortality nor mature parasite production were reduced when fish were exposed to genotype II prior to genotype I compared with fish exposed only to genotype I, suggesting that protection against C. shasta using a less-virulent genotype of the parasite does not occur.
Collapse
Affiliation(s)
- C N Hurst
- a Department of Microbiology , Oregon State University , Nash Hall 226, Corvallis , Oregon 97331 , USA
| | | |
Collapse
|
36
|
Ayre KK, Caldwell CA, Stinson J, Landis WG. Analysis of regional scale risk of whirling disease in populations of Colorado and Rio Grande cutthroat trout using a Bayesian belief network model. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2014; 34:1589-605. [PMID: 24660663 DOI: 10.1111/risa.12189] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Introduction and spread of the parasite Myxobolus cerebralis, the causative agent of whirling disease, has contributed to the collapse of wild trout populations throughout the intermountain west. Of concern is the risk the disease may have on conservation and recovery of native cutthroat trout. We employed a Bayesian belief network to assess probability of whirling disease in Colorado River and Rio Grande cutthroat trout (Oncorhynchus clarkii pleuriticus and Oncorhynchus clarkii virginalis, respectively) within their current ranges in the southwest United States. Available habitat (as defined by gradient and elevation) for intermediate oligochaete worm host, Tubifex tubifex, exerted the greatest influence on the likelihood of infection, yet prevalence of stream barriers also affected the risk outcome. Management areas that had the highest likelihood of infected Colorado River cutthroat trout were in the eastern portion of their range, although the probability of infection was highest for populations in the southern, San Juan subbasin. Rio Grande cutthroat trout had a relatively low likelihood of infection, with populations in the southernmost Pecos management area predicted to be at greatest risk. The Bayesian risk assessment model predicted the likelihood of whirling disease infection from its principal transmission vector, fish movement, and suggested that barriers may be effective in reducing risk of exposure to native trout populations. Data gaps, especially with regard to location of spawning, highlighted the importance in developing monitoring plans that support future risk assessments and adaptive management for subspecies of cutthroat trout.
Collapse
Affiliation(s)
- Kimberley Kolb Ayre
- Institute of Environmental Toxicology, Huxley College of the Environment, Western Washington University, Bellingham, WA, USA
| | | | | | | |
Collapse
|
37
|
Borkhanuddin MH, Cech G, Molnár K, Németh S, Székely C. Description of raabeia, synactinomyxon and neoactinomyxum developing stages of myxosporeans (Myxozoa) infecting Isochaetides michaelseni Lastočkin (Tubificidae) in Lake Balaton and Kis-Balaton Water Reservoir, Hungary. Syst Parasitol 2014; 88:245-59. [PMID: 24935127 DOI: 10.1007/s11230-014-9496-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 04/27/2014] [Indexed: 10/25/2022]
Abstract
Molecular and morphometric investigations were conducted on the actinosporean morphotypes of myxosporeans surveyed in oligochaetes of Lake Balaton and Kis-Balaton Water reservoir. Oligochaetes belonging to the species Isochaetides michaelseni Lastočkin and Branchiura sowerbyi Beddard as well as to the genera Nais Dujardin, Dero Müller and Aeolosoma Ehrenberg were studied during an 18-month period. Actinosporeans were obtained exclusively from I. michaelseni (7,818 specimens) with very low prevalence (0.01-0.06%). Four new actinosporean morphotypes of the collective groups raabeia (2 types), synactinomyxon (1 type) and neoactinomyxum (1 type) were found and described, including the first synactinomyxon collective group from Hungarian biotopes and a new raabeia morphotype. Except for Synactinomyxon type 1, the 18S rDNA analysis revealed that the spores did not match any myxospore entity found in the GenBank.
Collapse
|
38
|
Scholz T, Choudhury A. Parasites of Freshwater Fishes In North America: Why So Neglected? J Parasitol 2014; 100:26-45. [DOI: 10.1645/13-394.1] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
|
39
|
Baerwald MR. Temporal expression patterns of rainbow trout immune-related genes in response to Myxobolus cerebralis exposure. FISH & SHELLFISH IMMUNOLOGY 2013; 35:965-971. [PMID: 23867493 DOI: 10.1016/j.fsi.2013.07.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 07/08/2013] [Indexed: 06/02/2023]
Abstract
Infection of salmonids by the myxozoan parasite Myxobolus cerebralis can cause whirling disease, which is responsible for high mortalities in rainbow trout hatcheries and natural populations in the United States. Although considerable research has provided insight into disease pathology, host invasion, and inheritance patterns of resistance, the causal genetic variants and molecular mechanisms underlying host resistance or susceptibility remain elusive. A previous study found that expression changes of specific metallothionein genes following M. cerebralis infection are implicated in whirling disease resistance. The present study examines the dynamic transcriptional response to infection of several upstream regulators of the metallothionein gene family (IL-1β, KLF2, STAT3, STAT5), along with innate immune response genes (IFN-γ, IRF1 and iNOS). Pathogen loads and gene expression were compared across multiple time points after M. cerebralis exposure to elucidate how resistant and susceptible rainbow trout strains transcriptionally respond to early invasion. IL-1β, IFN-γ, IRF1, and iNOS all showed increased expression following M. cerebralis exposure for one or both strains across multiple time points. The interferon-related genes IFN-γ and IRF1 had consistently increased expression in the susceptible strain in comparison to the resistant strain, likely due to a less effective initial immune response. STAT3 was the only gene with consistently increased expression in the resistant strain following infection while remaining unchanged in the susceptible strain. Given its pleiotropic effects on immune response, STAT3 is an excellent candidate for future research of whirling disease resistance mechanisms.
Collapse
Affiliation(s)
- Melinda R Baerwald
- Genomic Variation Laboratory, Department of Animal Science, University of California Davis, One Shields Avenue, Davis, CA 95616, USA.
| |
Collapse
|
40
|
Baxa DV, Stover A, Clifford M, Kurobe T, Teh SJ, Moyle P, Hedrick RP. Henneguya sp. in yellowfin goby Acanthogobius flavimanus from the San Francisco Estuary. SPRINGERPLUS 2013; 2:420. [PMID: 24024104 PMCID: PMC3765604 DOI: 10.1186/2193-1801-2-420] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 08/27/2013] [Indexed: 11/16/2022]
Abstract
Myxozoan spores were observed in yellowfin goby Acanthogobius flavimanus collected from Suisun Marsh, San Francisco Estuary (SFE). Although histopathological changes associated with the parasite were not observed, the spores formed plasmodia that partially blocked the gastric and intestinal mucosa and gut lumen and may affect the perfomance and survival of the yellowfin goby. Morphological features of the spores resembled Henneguya sp. and molecular analysis of the 18S ribosomal DNA (Domain III) confirmed close similarity to H. rhinogobii and H. pseudorhinogobii isolated from the Japanese freshwater goby. The yellowfin goby myxozoan however, is likely an undescribed species based on phylogenetic analysis and morphologic features. Detailed description of vegetative and spore stages are currently lacking for proposal to a new species of Henneguya. A specific PCR test was developed, which confirmed a 100% prevalence of the parasite among randomly collected gobies in group 1 (N = 30) and group 2 (N = 15) at termination of the study at one month in captivity. The myxozoan was also detected from 18 gobies (12%) that died in the first group within two weeks in captivity. Apparently healthy gobies that served as controls did not reveal the presence of the myxozoan by PCR. This study documents the occurrence of a potentially new species of myxozoan in the yellowfin goby and underscores the detection of a parasitic infection in an introduced fish in the SFE. Although the pathogenesis of the myxozoan was not assessed and the prevalence as reported here is restricted to a comparatively small collection site in Suisun slough, the reemergence, identification, and ecological relevance of the parasite on goby populations in the SFE may be investigated in the future using the specific diagnostic tool developed in this study.
Collapse
Affiliation(s)
- Dolores V Baxa
- />School of Veterinary Medicine, Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, CA 95616 USA
- />School of Veterinary Medicine, Department of Medicine and Epidemiology, University of California, Davis, CA 95616 USA
| | - Alison Stover
- />Wildlife, Fish, and Conservation Biology, Center for Watershed Sciences, University of California, Davis, CA 95616 USA
| | - Mark Clifford
- />California Department of Fish and Wildlife, #3 North Old Stage Road, Mt. Shasta, CA 96067 USA
| | - Tomofumi Kurobe
- />School of Veterinary Medicine, Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, CA 95616 USA
| | - Swee J Teh
- />School of Veterinary Medicine, Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, CA 95616 USA
| | - Peter Moyle
- />Wildlife, Fish, and Conservation Biology, Center for Watershed Sciences, University of California, Davis, CA 95616 USA
| | - Ronald P Hedrick
- />School of Veterinary Medicine, Department of Medicine and Epidemiology, University of California, Davis, CA 95616 USA
| |
Collapse
|
41
|
Schmidt-Posthaus H, Steiner P, Müller B, Casanova-Nakayama A. Complex interaction between proliferative kidney disease, water temperature and concurrent nematode infection in brown trout. DISEASES OF AQUATIC ORGANISMS 2013; 104:23-34. [PMID: 23670077 DOI: 10.3354/dao02580] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Proliferative kidney disease (PKD) is a temperature-dependent disease caused by the myxozoan Tetracapsuloides bryosalmonae. It is an emerging threat to wild brown trout Salmo trutta fario populations in Switzerland. Here we examined (1) how PKD prevalence and pathology in young-of-the-year (YOY) brown trout relate to water temperature, (2) whether wild brown trout can completely recover from T. bryosalmonae-induced renal lesions and eliminate T. bryosalmonae over the winter months, and (3) whether this rate and/or extent of the recovery is influenced by concurrent infection. A longitudinal field study on a wild brown trout cohort was conducted over 16 mo. YOY and age 1+ fish were sampled from 7 different field sites with various temperature regimes, and monitored for infection with T. bryosalmonae and the nematode Raphidascaris acus. T. bryosamonae was detectable in brown trout YOY from all sampling sites, with similar renal pathology, independent of water temperature. During winter months, recovery was mainly influenced by the presence or absence of concurrent infection with R. acus larvae. While brown trout without R. acus regenerated completely, concurrently infected brown trout showed incomplete recovery, with chronic renal lesions and incomplete translocation of T. bryosalmonae from the renal interstitium into the tubular lumen. Water temperature seemed to influence complete excretion of T. bryosalmonae, with spores remaining in trout from summer-warm rivers, but absent in trout from summer-cool rivers. In the following summer months, we found PKD infections in 1+ brown trout from all investigated river sites. The pathological lesions indicated a re-infection rather than a proliferation of remaining T. bryosalmonae. However, disease prevalence in 1+ trout was lower than in YOY.
Collapse
Affiliation(s)
- Heike Schmidt-Posthaus
- Centre for Fish and Wildlife Health, Institute of Animal Pathology, University of Berne, Laenggassstrasse 122, PO Box 8466, 3001 Berne, Switzerland
| | | | | | | |
Collapse
|
42
|
McKenzie VJ, Peterson AC. Pathogen pollution and the emergence of a deadly amphibian pathogen. Mol Ecol 2013; 21:5151-4. [PMID: 23075064 DOI: 10.1111/mec.12013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Imagine a single pathogen that is responsible for mass mortality of over a third of an entire vertebrate class. For example, if a single pathogen were causing the death, decline and extinction of 30% of mammal species (including humans), the entire world would be paying attention. This is what has been happening to the world's amphibians - the frogs, toads and salamanders that are affected by the chytrid fungal pathogen, Batrachochytrium dendrobatidis (referred to as Bd), which are consequently declining at an alarming rate. It has aptly been described as the worst pathogen in history in terms of its effects on biodiversity (Kilpatrick et al. 2010). The pathogen was only formally described about 13 years ago (Longcore et al. 1999), and scientists are still in the process of determining where it came from and investigating the question: why now? Healthy debate has ensued as to whether Bd is a globally endemic organism that only recently started causing high mortality due to shifting host responses and/or environmental change (e.g. Pounds et al. 2006) or whether a virulent strain of the pathogen has rapidly disseminated around the world in recent decades, affecting new regions with a vengeance (e.g. Morehouse et al. 2003; Weldon et al. 2004; Lips et al. 2008). We are finally beginning to shed more light on this question, due to significant discoveries that have emerged as a result of intensive DNA-sequencing methods comparing Bd isolates from different amphibian species across the globe. Evidence is mounting that there is indeed a global panzootic lineage of Bd (BdGPL) in addition to what appear to be more localized endemic strains (Fisher et al. 2009; James et al. 2009; Farrer et al. 2011). Additionally, BdGPL appears to be a hypervirulent strain that has resulted from the hybridization of different Bd strains that came into contact in recent decades, and is now potentially replacing the less-virulent endemic strains of the pathogen (Farrer et al. 2011). In a new study published in this issue of Molecular Ecology, Schloegel et al. (2012) identify an additional unique Bd lineage that is endemic to the Atlantic Brazilian rainforests (Bd-Brazil) and provide striking evidence that the Bd-Brazil lineage has sexually recombined with the BdGPL lineage in an area where the two lineages likely came into contact as a result of classic anthropogenically mediated 'pathogen pollution'(see below). Fungal pathogens, including Bd, have the propensity to form recombinant lineages when allopatric populations that have not yet formed genetic reproductive barriers are provided with opportunities to intermingle, and virulent strains may be selected for because they tend to be highly transmissible (Fisher et al. 2012). As Schloegel et al. (2012) point out, the demonstrated ability for Bd to undergo meiosis may also mean that it has the capacity to form a resistant spore stage (as yet undiscovered), based on extrapolation from other sexually reproducing chytrids that all have spore stages.
Collapse
Affiliation(s)
- Valerie J McKenzie
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA.
| | | |
Collapse
|
43
|
Neudecker RA, McMahon TE, Vincent ER. Spatial and temporal variation of whirling disease risk in Montana spring creeks and rivers. JOURNAL OF AQUATIC ANIMAL HEALTH 2012; 24:201-212. [PMID: 23025590 DOI: 10.1080/08997659.2012.694833] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Spring creeks are important spawning and rearing areas for wild trout, but the stable flows, cool temperatures, and high nutrient levels that characterize these unique habitats may also make them highly susceptible to establishment and proliferation of the whirling disease pathogen Myxobolus cerebralis. We evaluated the spatial and temporal dynamics in whirling disease risk by using sentinel rainbow trout Oncorhynchus mykiss fry in nine different spring creeks and their conjoining rivers or reservoirs in Montana over a 20-month period. Whirling disease risk was high in five of the seven pathogen-positive spring creek study sites; at these sites, prevalence levels exceeded 90% and over 50% of sentinel fry had moderate to high infection severity scores. Spring creeks generally had higher disease prevalence and severity than paired river or reservoir sites. Fine sediment levels varied widely among springs creeks with high and low whirling disease risk, and we found no significant association between fine sediment level and infection severity. The low risk measured for some spring creeks was likely attributable to the pathogen invasion being in its early stages rather than to environmental characteristics limiting the severity of infection. High whirling disease risk occurred over a wide range of temperatures at spring creek sites (4.5-13°C) and river sites (1.7-12.5°C). There was an unusual seasonal cycle of infection in spring creeks, with peak infection levels occurring from late fall to early spring and declining to near zero in late spring to early fall. The low infection risk during spring suggests that spring-spawning trout would be at a low risk of infection, even in spring creeks with otherwise high disease severity. In contrast, fry of fall-spawning trout may be much more susceptible to infection in spring creek environments.
Collapse
Affiliation(s)
- Ryen A Neudecker
- Ecology Department, Fish and Wildlife Ecology and Management Program , Montana State University, Bozeman, MT, USA
| | | | | |
Collapse
|
44
|
Vittecoq M, Grandhomme V, Champagnon J, Guillemain M, Crescenzo-Chaigne B, Renaud F, Thomas F, Gauthier-Clerc M, van der Werf S. High influenza a virus infection rates in Mallards bred for hunting in the Camargue, South of France. PLoS One 2012; 7:e43974. [PMID: 22952832 PMCID: PMC3428329 DOI: 10.1371/journal.pone.0043974] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 07/27/2012] [Indexed: 11/19/2022] Open
Abstract
During the last decade, the role of wildlife in emerging pathogen transmission to domestic animals has often been pointed out. Conversely, far less attention has been paid to pathogen transmission from domestic animals to wildlife. Here, we focus on the case of game restocking, which implies the release of millions of animals worldwide each year. We conducted a 2-year study in the Camargue (Southern France) to investigate the influence of hand-reared Mallard releases on avian influenza virus dynamics in surrounding wildlife. We sampled Mallards (cloacal swabs) from several game duck facilities in 2009 and 2010 before their release. A very high (99%) infection rate caused by an H10N7 strain was detected in the game bird facility we sampled in 2009. We did not detect this strain in shot ducks we sampled, neither during the 2008/2009 nor the 2009/2010 hunting seasons. In 2010 infection rates ranged from 0 to 24% in hand-reared ducks. The 2009 H10N7 strain was fully sequenced. It results from multiple reassortment events between Eurasian low pathogenic strains. Interestingly, H10N7 strains had previously caused human infections in Egypt and Australia. The H10 and N7 segments we sequenced were clearly distinct from the Australian ones but they belonged to the same large cluster as the Egyptian ones. We did not observe any mutation linked to increased virulence, transmission to mammals, or antiviral resistance in the H10N7 strain we identified. Our results indicate that the potential role of hand-reared Mallards in influenza virus epizootics must be taken into account given the likely risk of viral exchange between game bird facilities and wild habitats, owing to duck rearing conditions. Measures implemented to limit transmission from wildlife to domestic animals as well as measures to control transmission from domestic animals to wild ones need to be equally reinforced.
Collapse
|
45
|
Wagner EJ, Bartley M, Arndt R, Oplinger RW, Routledge MD. Comparison of hatchery and field performance between a whirling-disease-resistant strain and the Ten Sleep strain of rainbow trout. JOURNAL OF AQUATIC ANIMAL HEALTH 2012; 24:110-120. [PMID: 22838082 DOI: 10.1080/08997659.2012.675938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A whirling-disease-resistant strain of rainbow trout Oncorhynchus mykiss (GRHL strain) derived from a backcross of an F1 hybrid of two strains (German strain x Harrison Lake strain) with German strain females, was compared with the Ten Sleep (TS) strain of rainbow trout. The GRHL strain had consistently superior growth and feed conversion in two consecutive hatchery trials. Hatching and mortality rates were similar between strains. Both strains were stocked into two Utah reservoirs (Hyrum, Porcupine), and a third, Causey Reservoir, was monitored as a control for seasonal variation in prevalence of Myxobolus cerebralis. A total of 1,323 salmonids captured by gill net in spring and fall sampling between 2006 and 2008 were tested for M. cerebralis via pepsin-trypsin digest methods. Only eight of these (< 1% per species) had clinical signs consistent with whirling disease. In both reservoirs, GRHL survived better than the TS and had higher growth rates. The prevalence of M. cerebralis was significantly lower for GRHL (18.1%) than TS (50.0%) in Porcupine Reservoir. In Hyrum Reservoir the trend was similar, but prevalence was lower and did not significantly differ between GRHL (9.6%) and TS (23.1%). For infected fish, no significant differences were observed between strains in myxospore counts in either Hyrum (GRHL = 911-28,244 spores/fish [spf], TS = 1,822-155,800 spf) or Porcupine (GRHL = 333-426,667spf, TS = 333-230,511 spf) reservoirs. Unmarked rainbow trout in both reservoirs had significantly higher myxospore counts than stocked fish of either strain. There were significant differences in M. cerebralis prevalence and myxospore loads among other naturally reproducing salmonids in the reservoirs. The trend in susceptibility was cutthroat trout Oncorhynchus clarkii > kokanee Oncorhynchus nerka > brown trout Salmo trutta. The GRHL performed well in both hatchery and field settings and is recommended for stocking programs.
Collapse
Affiliation(s)
- Eric J Wagner
- Fisheries Experiment Station, 1465 West 200 North, Logan, Utah 84321, USA.
| | | | | | | | | |
Collapse
|
46
|
Hedrick RP, McDowell TS, Adkison MA, Myklebust KA, Mardones FO, Petri B. Invasion and initial replication of ultraviolet irradiated waterborne infective stages of Myxobolus cerebralis results in immunity to whirling disease in rainbow trout. Int J Parasitol 2012; 42:657-66. [PMID: 22580732 DOI: 10.1016/j.ijpara.2012.04.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 04/12/2012] [Accepted: 04/15/2012] [Indexed: 10/28/2022]
Abstract
Myxobolus cerebralis is a microscopic metazoan parasite (Phylum Myxozoa: Myxosporea) associated with salmonid whirling disease. There are currently no vaccines to minimise the serious negative economical and ecological impacts of whirling disease among populations of salmonid fish worldwide. UV irradiation has been shown to effectively inactivate the waterborne infective stages or triactinomyxons of M. cerbralis in experimental and hatchery settings but the mechanisms by which the parasite is compromised are unknown. Treatments of triactinomyxons with UV irradiation at doses from 10 to 80 mJ/cm(2) either prevented (20-80 mJ/cm(2)) or significantly inhibited (10 mJ/cm(2)) completion of the parasite life cycle in experimentally exposed juvenile rainbow trout (Oncorhynchus mykiss). However, even the highest doses of UV irradiation examined (80 mJ/cm(2)) did not prevent key steps in the initiation of parasite infection, including attachment and penetration of the epidermis of juvenile rainbow trout as demonstrated by scanning electron and light microscopy. Furthermore, replication of UV-treated parasites within the first 24h following invasion of the caudal fin was suggested by the detection of concentrations of parasite DNA by quantitative PCR comparable to that among fish exposed to an equal concentration of untreated triactinomyxons. Subsequent development of parasites treated with an 80 mJ/cm(2) dose of UV irradiation however, was impaired as demonstrated by the decline and then lack of detection of parasite DNA; a trend beginning at 10 days and continuing thereafter until the end of the study at 46 days post parasite exposure. Treatments of triactinomyxons with a lower dose of UV irradiation (20 mJ/cm(2)) resulted in a more prolonged survival with parasite DNA detected, although at very low concentrations, in fish up to 49 days post parasite exposure. The successful invasion but only short-term survival of parasites treated with UV in rainbow trout resulted in a protective response to challenges with fully infective triactinomyxons. Prior treatments of juvenile rainbow trout with UV-treated triactinomyxons (10 and 20 mJ/cm(2)) resulted in a reduced prevalence of infection and significantly lower concentrations of cranial myxospores (two direct measures of the severity of whirling disease) compared with trout receiving no prior treatments when assessed 5 months post parasite exposure to fully infective triactinomyxons.
Collapse
Affiliation(s)
- Ronald P Hedrick
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
| | | | | | | | | | | |
Collapse
|
47
|
Lodh N, Stevens L, Kerans B. Prevalence of Myxobolus cerebralis Infections Among Genetic Lineages of Tubifex tubifex at Three Locations in the Madison River, Montana. J Parasitol 2011; 97:531-4. [DOI: 10.1645/ge-2497.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
48
|
Hartigan A, Fiala I, Dyková I, Jirků M, Okimoto B, Rose K, Phalen DN, Šlapeta J. A suspected parasite spill-back of two novel Myxidium spp. (Myxosporea) causing disease in Australian endemic frogs found in the invasive Cane toad. PLoS One 2011; 6:e18871. [PMID: 21541340 PMCID: PMC3081827 DOI: 10.1371/journal.pone.0018871] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2010] [Accepted: 03/22/2011] [Indexed: 01/21/2023] Open
Abstract
Infectious diseases are contributing to the decline of endangered amphibians. We identified myxosporean parasites, Myxidium spp. (Myxosporea: Myxozoa), in the brain and liver of declining native frogs, the Green and Golden Bell frog (Litoria aurea) and the Southern Bell frog (Litoria raniformis). We unequivocally identified two Myxidium spp. (both generalist) affecting Australian native frogs and the invasive Cane toad (Bufo marinus, syn. Rhinella marina) and demonstrated their association with disease. Our study tested the identity of Myxidium spp. within native frogs and the invasive Cane toad (brought to Australia in 1935, via Hawaii) to resolve the question whether the Cane toad introduced them to Australia. We showed that the Australian brain and liver Myxidium spp. differed 9%, 7%, 34% and 37% at the small subunit rDNA, large subunit rDNA, internal transcribed spacers 1 and 2, but were distinct from Myxidium cf. immersum from Cane toads in Brazil. Plotting minimum within-group distance against maximum intra-group distance confirmed their independent evolutionary trajectory. Transmission electron microscopy revealed that the brain stages localize inside axons. Myxospores were morphologically indistinguishable, therefore genetic characterisation was necessary to recognise these cryptic species. It is unlikely that the Cane toad brought the myxosporean parasites to Australia, because the parasites were not found in 261 Hawaiian Cane toads. Instead, these data support the enemy-release hypothesis predicting that not all parasites are translocated with their hosts and suggest that the Cane toad may have played an important spill-back role in their emergence and facilitated their dissemination. This work emphasizes the importance of accurate species identification of pathogens relevant to wildlife management and disease control. In our case it is paving the road for the spill-back role of the Cane toad and the parasite emergence.
Collapse
Affiliation(s)
- Ashlie Hartigan
- Faculty of Veterinary Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Ivan Fiala
- Institute of Parasitology, Biology Centre, Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Iva Dyková
- Institute of Parasitology, Biology Centre, Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Miloslav Jirků
- Institute of Parasitology, Biology Centre, Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Ben Okimoto
- Honolulu Zoo, Honolulu, Oahu, Hawaii, United States of America
| | - Karrie Rose
- Australian Registry of Wildlife Health, Taronga Conservation Society Australia, Mosman, New South Wales, Australia
| | - David N. Phalen
- Faculty of Veterinary Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Jan Šlapeta
- Faculty of Veterinary Science, The University of Sydney, Sydney, New South Wales, Australia
- * E-mail:
| |
Collapse
|
49
|
Hartigan A, Phalen DN, Slapeta J. Museum material reveals a frog parasite emergence after the invasion of the cane toad in Australia. Parasit Vectors 2010; 3:50. [PMID: 20537137 PMCID: PMC2901343 DOI: 10.1186/1756-3305-3-50] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Accepted: 06/10/2010] [Indexed: 11/10/2022] Open
Abstract
Background A parasite morphologically indistinguishable from Myxidium immersum (Myxozoa: Myxosporea) found in gallbladders of the invasive cane toad (Bufo marinus) was identified in Australian frogs. Because no written record exists for such a parasite in Australian endemic frogs in 19th and early 20th century, it was assumed that the cane toad introduced this parasite. While we cannot go back in time ourselves, we investigated whether material at the museum of natural history could be used to retrieve parasites, and whether they were infected at the time of their collection (specifically prior to and after the cane toad translocation to Australia in 1935). Results Using the herpetological collection at the Australian Museum we showed that no myxospores were found in any animals (n = 115) prior to the cane toad invasion (1879-1935). The green and golden bell frog (Litoria aurea), the Peron's tree frog (Litoria peronii), the green tree frog (Litoria caerulea) and the striped marsh frog (Limnodynastes peronii) were all negative for the presence of the parasite using microscopy of the gallbladder content and its histology. These results were sufficient to conclude that the population was free from this disease (at the expected minimum prevalence of 5%) at 99.7% confidence level using the 115 voucher specimens in the Australian Museum. Similarly, museum specimens (n = 29) of the green and golden bell frog from New Caledonia, where it was introduced in 19th century, did not show the presence of myxospores. The earliest specimen positive for myxospores in a gallbladder was a green tree frog from 1966. Myxospores were found in eight (7.1%, n = 112) frogs in the post cane toad introduction period. Conclusion Australian wildlife is increasingly under threat, and amphibian decline is one of the most dramatic examples. The museum material proved essential to directly support the evidence of parasite emergence in Australian native frogs. This parasite can be considered one of the luckiest parasites, because it has found an empty niche in Australia. It now flourishes in > 20 endemic and exotic frog species, but its consequences are yet to be fully understood.
Collapse
Affiliation(s)
- Ashlie Hartigan
- Faculty of Veterinary Science, University of Sydney, New South Wales 2006, Australia.
| | | | | |
Collapse
|
50
|
Infection dynamics of two renal myxozoans in hatchery reared fry and juvenile Atlantic cod Gadus morhua L. Parasitology 2010; 137:1501-13. [PMID: 20500915 DOI: 10.1017/s0031182010000247] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In order to study the infection dynamics of 2 renal myxozoans, Zschokkella hildae Auerbach, 1910 and Gadimyxa atlantica Køie, Karlsbakk and Nylund, 2007 in cultured Atlantic cod, Gadus morhua L. aged 3-19 months, a specific single-round PCR assay and a double-label in situ hybridization protocol were developed. The results demonstrated that the 2 myxozoans show spatial separation of their development with regard to spore formation inside the renal tubules versus the collecting ducts and ureters, as well as temporal separation with Z. hildae proliferating and developing spores only once the G. atlantica infection decreases, despite the presence of both myxozoans in the smallest fry studied. These results strongly suggest within-host competition of the 2 myxozoans with potential suppression of Z. hildae by G. atlantica until G. morhua acquires immunity against G. atlantica. The quantification of the G. atlantica infection inside the renal tubules before and after a 29-day experimental growth performance study using fry from hatcheries with differing filtration systems showed that the intensity of infection with G. atlantica seems to be controlled if prolonged exposure to the myxozoan transmission stages takes place from hatching onwards. Surprisingly, growth rates in the trial were inversely affected suggesting that G. atlantica does not negatively influence cod fry growth performance.
Collapse
|