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Nekouei O, Vanderstichel R, Kaukinen KH, Thakur K, Ming T, Patterson DA, Trudel M, Neville C, Miller KM. Comparison of infectious agents detected from hatchery and wild juvenile Coho salmon in British Columbia, 2008-2018. PLoS One 2019; 14:e0221956. [PMID: 31479469 PMCID: PMC6719873 DOI: 10.1371/journal.pone.0221956] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 08/19/2019] [Indexed: 02/03/2023] Open
Abstract
Infectious diseases are potential contributors to decline in Coho salmon (Oncorhynchus kisutch) populations. Although pathogens are theoretically considered to pose higher risk in high-density rearing environments like hatcheries, there is no direct evidence that hatchery-origin Coho salmon increase the transmission of infectious agents to sympatric wild populations. This study was undertaken to compare prevalence, burden, and diversity of infectious agents between hatchery-reared and wild juvenile Coho salmon in British Columbia (BC), Canada. In total, 2,655 juvenile Coho salmon were collected between 2008 and 2018 from four regions of freshwater and saltwater in BC. High-throughput microfluidics qPCR was employed for simultaneous detection of 36 infectious agents from mixed-tissue samples (gill, brain, heart, liver, and kidney). Thirty-one agents were detected at least once, including ten with prevalence >5%. Candidatus Brachiomonas cysticola, Paraneuclospora theridion, and Parvicapsula pseudobranchiocola were the most prevalent agents. Diversity and burden of infectious agents were substantially higher in marine environment than in freshwater. In Mainland BC, infectious burden and diversity were significantly lower in hatchery smolts than in wild counterparts, whereas in other regions, there were no significant differences. Observed differences in freshwater were predominantly driven by three parasites, Loma salmonae, Myxobolus arcticus, and Parvicapsula kabatai. In saltwater, there were no consistent differences in agent prevalence between hatchery and wild fish shared among the west and east coasts of Vancouver Island. Although some agents showed differential infectious patterns between regions, annual variations likely contributed to this signal. Our findings do not support the hypothesis that hatchery smolts carry higher burdens of infectious agents than conspecific wild fish, reducing the potential risk of transfer to wild smolts at this life stage. Moreover, we provide a baseline of infectious agents in juvenile Coho salmon that will be used in future research and modeling potential correlations between infectious profiles and marine survival.
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Affiliation(s)
- Omid Nekouei
- Department of Health Management, University of Prince Edward Island, Charlottetown, PE, Canada
- * E-mail:
| | - Raphael Vanderstichel
- Department of Health Management, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Karia H. Kaukinen
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Krishna Thakur
- Department of Health Management, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Tobi Ming
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - David A. Patterson
- Fisheries and Oceans Canada, Cooperative Resource Management Institute, School of Resources and Environment Management, Simon Fraser University, Burnaby, BC, Canada
| | - Marc Trudel
- St. Andrews Biological Station, Fisheries and Oceans Canada, St. Andrews, NB, Canada
| | - Chrys Neville
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
| | - Kristina M. Miller
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada
- Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada
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Atkinson SD, Hallett SL, Díaz-Morales D, Bartholomew JL, Buron ID. First Myxozoan Infection (Cnidaria: Myxosporea) in a Marine Polychaete from North America and Erection of Actinospore Collective Group Saccimyxon. J Parasitol 2019. [DOI: 10.1645/18-183] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Affiliation(s)
- Stephen D. Atkinson
- Department of Microbiology, Oregon State University, Nash Hall 226, Corvallis, Oregon 97331
| | - Sascha L. Hallett
- Department of Microbiology, Oregon State University, Nash Hall 226, Corvallis, Oregon 97331
| | - Dakeishla Díaz-Morales
- Department of Environmental Science, University of Puerto Rico, Rio Piedras, San Juan, Puerto Rico 00931-3346
| | - Jerri L. Bartholomew
- Department of Microbiology, Oregon State University, Nash Hall 226, Corvallis, Oregon 97331
| | - Isaure de Buron
- Department of Biology, College of Charleston, 205 Ft. Johnson Road, Charleston, South Carolina 29412
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Nylund A, Hansen H, Brevik ØJ, Hustoft H, Markussen T, Plarre H, Karlsbakk E. Infection dynamics and tissue tropism of Parvicapsula pseudobranchicola (Myxozoa: Myxosporea) in farmed Atlantic salmon (Salmo salar). Parasit Vectors 2018; 11:17. [PMID: 29306320 PMCID: PMC5756351 DOI: 10.1186/s13071-017-2583-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 12/11/2017] [Indexed: 11/10/2022] Open
Abstract
Background The myxosporean parasite Parvicapsula pseudobranchicola commonly infects farmed Atlantic salmon in northern Norway. Heavy infections are associated with pseudobranch lesions, runting and mortality in the salmon populations. The life-cycle of the parasite is unknown, preventing controlled challenge experiments. The infection dynamics, duration of sporogony, tissue tropism and ability to develop immunity to the parasite in farmed Atlantic salmon is poorly known. We conducted a field experiment, aiming at examining these aspects. Methods Infections in a group of Atlantic salmon were followed from before sea-transfer to the end of the production (604 days). Samples from a range of tissues/sites were analysed using real-time RT-PCR and histology, including in situ hybridization. Results All salmon in the studied population rapidly became infected with P. pseudobranchicola after sea-transfer medio August. Parasite densities in the pseudobranchs peaked in winter (November-January), and decreased markedly to March. Densities thereafter decreased further. Parasite densities in other tissues were low. Parasite stages were initially found to be intravascular in the pseudobranch, but occurred extravascular in the pseudobranch tissue at 3 months post-sea-transfer. Mature spores appeared in the pseudobranchs in the period with high parasite densities in the winter (late November-January), and were released (i.e. disappeared from the fish) in the period January-March. Clinical signs of parvicapsulosis (December-early February) were associated with high parasite densities and inflammation in the pseudobranchs. No evidence for reinfection was seen the second autumn in sea. Conclusions The main site of the parasite in Atlantic salmon is the pseudobranchs. Blood stages occur, but parasite proliferation is primarily associated with extravascular stages in the pseudobranchs. Disease and mortality (parvicapsulosis) coincide with the completion of sporogony. Atlantic salmon appears to develop immunity to P. pseudobranchicola. Further studies should focus on the unknown life-cycle of the parasite, and the pathophysiological effects of the pseudobranch infection that also could affect the eyes and vision. Electronic supplementary material The online version of this article (10.1186/s13071-017-2583-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Are Nylund
- Department of Biology, University of Bergen, 5020, Bergen, Norway
| | - Haakon Hansen
- Norwegian Veterinary Institute, PO Box 750 Sentrum, N-0106, Oslo, Norway
| | - Øyvind J Brevik
- Cermaq group AS, Dronning Eufemias gate16, P.O. Box 144, N-0102, Oslo, Norway
| | - Håvard Hustoft
- Department of Biology, University of Bergen, 5020, Bergen, Norway
| | - Turhan Markussen
- Norwegian Veterinary Institute, PO Box 750 Sentrum, N-0106, Oslo, Norway.,Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Heidrun Plarre
- Department of Biology, University of Bergen, 5020, Bergen, Norway
| | - Egil Karlsbakk
- Department of Biology, University of Bergen, 5020, Bergen, Norway. .,Institute of Marine Research, PO Box 1870, Nordnes, N-5817, Bergen, Norway.
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Özer A, Yurakhno V, Öztürk T, Kornyychuk YM. Myxosporean parasites of Ceratomyxa merlangi and Myxidium gadi in whiting Merlangius merlangus: a comparative epizootiological analysis based on samples from two localities off southern and northern coasts of the Black Sea. Parasitol Res 2017; 116:2463-2469. [PMID: 28710529 DOI: 10.1007/s00436-017-5550-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/29/2017] [Indexed: 11/25/2022]
Abstract
Totally 690 and 423 whiting Merlangius merlangus samples were collected from two localities off Southern (Sinop) and Northern coasts (Balaklava Bay) of the Black Sea, respectively, and examined for myxosporeans in the period from May 2011 to March 2014. Ceratomyxa merlangi and Myxidium gadi were the only myxosporean parasites identified in the content of gall bladder and their infection indices of prevalence (%) and intensity were calculated for length classes and sex of fish as well as for the seasons at both sampling localities. Overall infection prevalence of C. merlangi was 22.6% in Sinop and 27.9% in Balaklava samples while those values of M. gadi were 18.4% and 28.6% in Sinop and Balaklava samples, respectively. Both parasite species were also found to be co-existed in whiting samples. This is the first comprehensive epizootiological study yielded comparable data on C. merlangi and M. gadi infections in whiting in the southern and northern coasts of the Black Sea.
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Affiliation(s)
- A Özer
- Faculty of Fisheries and Aquatic Sciences, Sinop University, 57000, Sinop, Turkey.
| | - V Yurakhno
- A. O. Kovalevsky Institute of Marine Biological Research of RAS, 2 Nakhimov ave, Sevastopol, 299011, Crimea, Russia
| | - T Öztürk
- Faculty of Fisheries and Aquatic Sciences, Sinop University, 57000, Sinop, Turkey
| | - Y M Kornyychuk
- A. O. Kovalevsky Institute of Marine Biological Research of RAS, 2 Nakhimov ave, Sevastopol, 299011, Crimea, Russia
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Rangel LF, Rocha S, Casal G, Castro R, Severino R, Azevedo C, Cavaleiro F, Santos MJ. Life cycle inference and phylogeny of Ortholinea labracis n. sp. (Myxosporea: Ortholineidae), a parasite of the European seabass Dicentrarchus labrax (Teleostei: Moronidae), in a Portuguese fish farm. J Fish Dis 2017; 40:243-262. [PMID: 27307300 DOI: 10.1111/jfd.12508] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 04/22/2016] [Accepted: 04/25/2016] [Indexed: 06/06/2023]
Abstract
Ortholinea labracis n. sp. is described and its life cycle is inferred from a Southern Portuguese fish farm, with basis on microscopic and molecular procedures. This myxosporean parasite infects the urinary bladder of the European seabass Dicentrarchus labrax and the intestinal epithelium of a marine oligochaete of the genus Tectidrilus. Myxospores subspherical in valvular view and ellipsoidal in sutural view measuring 7.6 ± 0.3 (6.8-8.7) μm in length, 7.2 ± 0.2 (6.7-7.7) μm in width and 6.5 ± 0.4 (5.8-7.7) μm in thickness. Two polar capsules, 3.0 ± 0.2 (2.6-3.4) μm long and 2.4 ± 0.1 (2.0-2.9) μm wide, located at the same level, but with divergent orientation and opening to opposite sides of the suture line. Sequencing of the SSU rRNA gene revealed a similarity of 100% between the analysed myxospores and triactinomyxon actinospores. The phylogenetic setting of O. labracis n. sp. shows subgrouping in correlation with tissue tropism, but identifies this parasite as another exception to the main division of Myxosporea into the main freshwater and marine lineages.
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Affiliation(s)
- L F Rangel
- Laboratory of Animal Pathology, Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
| | - S Rocha
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
- Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - G Casal
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
- Department of Sciences, University Institute of Health Sciences, CESPU, Gandra, Portugal
| | - R Castro
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
| | - R Severino
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
| | - C Azevedo
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
- Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
- Zoology Department, College of Sciences, King Saud University, Riyadh, Saudi Arabia
| | - F Cavaleiro
- Laboratory of Animal Pathology, Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
| | - M J Santos
- Laboratory of Animal Pathology, Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
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Rangel LF, Castro R, Rocha S, Severino R, Casal G, Azevedo C, Cavaleiro F, Santos MJ. Tetractinomyxon stages genetically consistent with Sphaerospora dicentrarchi (Myxozoa: Sphaerosporidae) found in Capitella sp. (Polychaeta: Capitellidae) suggest potential role of marine polychaetes in parasite's life cycle. Parasitology 2016; 143:1067-73. [DOI: 10.1017/s0031182016000512] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
SUMMARYKnown life cycles of myxosporean parasites have two hosts, but very few life cycles have been disclosed, especially in the marine environment.Sphaerospora dicentrarchiSitjà-Bobadilla and Álvarez-Pellitero, 1992 is a systemic parasite from the European seabass,Dicentrarchus labrax(Linnaeus, 1758), a highly valuable commercial fish. It affects its health, leading to aquaculture production losses. During 2013 and 2014, an actinospore survey was conducted in a total of 5942 annelids collected from a fish farm in Algarve and from the Aveiro Estuary, in Portugal. A new tetractinomyxon actinospore was found in a capitellid polychaete, belonging to the generaCapitellacollected at the fish farm. The tetractinomyxons were pyriform measuring 11·1 ± 0·7µm in length and 7·2 ± 0·4µm in width, and presented three rounded polar capsules measuring 2·4 ± 0·3µm in diameter. The molecular analysis of the 18S rRNA gene sequences from the tetractinomyxons revealed a similarity of 100% with the DNA sequences deposited in the GenBank fromS. dicentrarchimyxospores collected from the European seabass and the spotted seabass in the same fish farm and 99·9% similarity with the DNA sequence obtained from the myxospores found infecting the European seabass in the Aveiro Estuary. Therefore, the new tetractinomyxons are inferred to represent the actinospore phase of theS. dicentrarchilife cycle.
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Thabet A, Mansour L, Al Omar SY, Tlig-Zouari S. Ceratomyxa tunisiensis n. sp. (Myxosporea: Bivalvulida) from the Gallbladders of Two Carangid Fish Caught Off the Coast of Tunisia. J Eukaryot Microbiol 2015; 63:86-92. [PMID: 26194329 DOI: 10.1111/jeu.12251] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 07/11/2015] [Indexed: 11/28/2022]
Abstract
A new coelozoic Myxozoan species, Ceratomyxa tunisiensis n. sp., was found infecting the gallbladders of two carangid fish, Caranx rhonchus and Trachurus trachurus (Perciforme, Carangidae), from the Gulf of Gabès, on the southern coast of Tunisia. The parasite develops in spherical mono-, diplo-, or polysporic tropozoites in the gallbladder of the hosts. Mature spores are typical of the genus Ceratomyxa. They are transversely elongated and narrowly crescent-shaped with a slightly convex anterior and concave posterior, and measure 23 ± 0. 27 (20-25) μm width × 6 ± 0.26 (5-8) μm in length. Spore shell valves are symmetrical with rounded ends. Two spherical polar capsules situated on either side of the sutural line measure 2.2 μm (2.0-3.0) in diam. Periodical sampling of C. rhonchus and T. trachurus from Marsh 2012 to February 2013 showed that infection due to C. tunisiensis occurs in 59% and 69% of the examined fish, respectively. Molecular analysis based on the small subunit (SSU) rRNA sequence shows high genetic divergence with all other ceratomyxid species. A Maximum Likelihood phylogenetic tree shows association with the species C. leatharjecketi Fiala, kova, Kodadkova, Freeman, Bartošova-Sojkova, and Atkinson, 2015 reported from the gallbladder of Aluterusmonoceros (L.) caught in the Andaman Sea, off Malaysia. Nonetheless, the SSU rRNA sequences of C. tunisiensis and C. leatharjecketi have only a 90% similarity.
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Affiliation(s)
- Aouatef Thabet
- Unité de Recherche de Biologie intégrative et Ecologie évolutive etFonctionnelle des Milieux Aquatiques, Département de Biologie, Faculté des Sciences de Tunis, Université De Tunis El Manar, Tunis, Tunisia.,Faculté des Sciences de Gabes, Université de Gabes, Cité Erriadh, 6072, Zrig Gabès, Tunisia
| | - Lamjed Mansour
- Unité de Recherche de Biologie intégrative et Ecologie évolutive etFonctionnelle des Milieux Aquatiques, Département de Biologie, Faculté des Sciences de Tunis, Université De Tunis El Manar, Tunis, Tunisia.,Zoology Department, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Suliman Y Al Omar
- Zoology Department, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Sabiha Tlig-Zouari
- Unité de Recherche de Biologie intégrative et Ecologie évolutive etFonctionnelle des Milieux Aquatiques, Département de Biologie, Faculté des Sciences de Tunis, Université De Tunis El Manar, Tunis, Tunisia
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Rangel LF, Rocha S, Castro R, Severino R, Casal G, Azevedo C, Cavaleiro F, Santos MJ. The life cycle of Ortholinea auratae (Myxozoa: Ortholineidae) involves an actinospore of the triactinomyxon morphotype infecting a marine oligochaete. Parasitol Res 2015; 114:2671-8. [DOI: 10.1007/s00436-015-4472-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 04/07/2015] [Indexed: 12/01/2022]
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Hansen H, Poppe TT, Markussen T, Karlsbakk E. Seatrout (Salmo trutta) is a natural host for Parvicapsula pseudobranchicola (Myxozoa, Myxosporea), an important pathogen of farmed Atlantic salmon (Salmo salar). Parasit Vectors 2015; 8:218. [PMID: 25890219 PMCID: PMC4397713 DOI: 10.1186/s13071-015-0828-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 03/25/2015] [Indexed: 11/10/2022] Open
Abstract
Background Parvicapsula pseudobranchicola (Myxozoa) causes widespread infections in farmed Atlantic salmon in northern Norway. Heavily infected salmon become runts, probably due to vision impairment or blindness. The salmon are likely infected by waterborne actinospores, released by an alternating annelid host, but the life cycle of P. pseudobranchicola is unknown. Seatrout and Arctic charr have been considered possible hosts for the parasite, but firm evidence has been lacking. Findings We show for the first time the presence of mature spores of P. pseudobranchicola in seatrout. The seatrout were infected with high intensities of P. pseudobranchicola in the pseudobranchs in early April. The presence of mature spores in early spring suggests that the fish had been infected late the previous year, a pattern of infection similar to that observed for farmed salmon stocked in autumn. Although heavily infected, the fish did not display any symptoms consistent with parvicapsulosis. The results suggest that the life cycle of P. pseudobranchicola is more adapted to seatrout, rather than to Atlantic salmon. Conclusions The presence of mature spores of P. pseudobranchicola in seatrout confirms that seatrout is a natural host for this myxosporean and this is also the first record of these spores in the pseudobranch of a wild salmonid. Furthermore, wild trout from non-farming areas may become heavily infected with P. pseudobranchicola, developing pseudobranch pathology resembling that of farmed Atlantic salmon suffering from parvicapsulosis.
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Affiliation(s)
- Haakon Hansen
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum, N-0106, Oslo, Norway.
| | - Trygve T Poppe
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum, N-0106, Oslo, Norway. .,Norwegian University of Life Sciences, School of Veterinary Medicine, P.O. Box 5003, N-1432, Ås, Norway.
| | - Turhan Markussen
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum, N-0106, Oslo, Norway.
| | - Egil Karlsbakk
- Institute of Marine Research, P.O. Box 1870, 5817, Nordnes Bergen, Norway.
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Markussen T, Agusti C, Karlsbakk E, Nylund A, Brevik Ø, Hansen H. Detection of the myxosporean parasite Parvicapsula pseudobranchicola in Atlantic salmon (Salmo salar L.) using in situ hybridization (ISH). Parasit Vectors 2015; 8:105. [PMID: 25889266 PMCID: PMC4334612 DOI: 10.1186/s13071-015-0718-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Accepted: 02/05/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Parvicapsula pseudobranchicola is a marine myxosporean parasite infecting farmed Atlantic salmon (Salmo salar). A major site for the parasite is the pseudobranch, which may be destroyed in heavily infected fish. Parvicapsulosis may be associated with significant mortality, although the main effect of infections seems to be runting. In situ hybridization (ISH) is, in the absence of specific antibodies, the preferred method for the detection of cell- and tissue tropisms of myxozoans in the early phases of infection of the host, and provides information about the possible association between the pathogen and pathology. A positive diagnosis of parvicapsulosis is based on histopathology and PCR. The aim of the present work was to develop a specific, sensitive and robust ISH assay for the detection of P. pseudobranchicola in tissues. METHODS The ISH method was designed to specifically target P. pseudobranchicola 18S rDNA/rRNA using a locked nucleic acid (LNA) modified oligonucleotide probe. The method was tested on paraffin embedded P. pseudobranchicola infected pseudobranchs. The infections were confirmed by light microscopy revealing the presence of typical P. pseudobranchicola trophozoites and spores, and the presence of parasite was confirmed with real-time RT-PCR. RESULTS Specific regions stained by ISH overlapped well with the parasitized and degenerated regions in neighbouring HE stained sections. No staining was observed in pseudobranchs of Atlantic salmon which had been held in P. pseudobranchicola-free water. CONCLUSIONS We report here the development of a sensitive ISH assay for the detection of P. pseudobranchicola in paraffin embedded tissue. The technique will be valuable in the study of host entry, early proliferation, pre-spore development, pathology and tissue tropism in Atlantic salmon.
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Affiliation(s)
- Turhan Markussen
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum, , N-0106, Oslo, Norway.
| | - Celia Agusti
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum, , N-0106, Oslo, Norway. .,Present address: Institute of Food Safety and Infection Biology, Norwegian University of Life Sciences, P.O. Box 8146, , Dep., NO-0033, Oslo, Norway.
| | - Egil Karlsbakk
- Institute of Marine Research, P.O. Box 1870, , Nordnes, 5817, Bergen, Norway.
| | - Are Nylund
- Department of Biology, University of Bergen, Thormøhlensgt 55, N-5020, Bergen, Norway.
| | - Øyvind Brevik
- Cermaq Group AS, Dronning Eufemias gate 16, N-0191, Oslo, Norway.
| | - Haakon Hansen
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum, , N-0106, Oslo, Norway.
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Abstract
Myxosporeans are among the most common parasites of marine fish. Their economic importance is mainly as pathogens of both wild and farmed fish, but they have also been used as biological tags in population studies of their fish hosts. Here we review the literature and show the distribution of different families of Myxosporea infecting marine fishes in the world's oceans - the North Atlantic, South Atlantic, North Pacific, South Pacific and Indian. We also analyse their distribution in different orders of marine fishes. New families, genera and species of marine Myxosporea are continually being described and many more await description. Some regions, in particular the North Atlantic, have been more thoroughly investigated than others, so the analyses we present may not reflect the true distributions and we acknowledge that these may change considerably as other regions are investigated more fully. The distribution of myxosporean families in different taxonomic groups of marine fishes can indicate phylogenetic relationships between parasite and host and suggest the origins of different myxosporean taxa. We present some examples, while recognizing that new molecular information on phylogenetic relationships within the Myxozoa will lead to major changes in classification.
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12
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Kodádková A, Dyková I, Tyml T, Ditrich O, Fiala I. Myxozoa in high Arctic: Survey on the central part of Svalbard archipelago. Int J Parasitol Parasites Wildl 2014; 3:41-56. [PMID: 24918076 PMCID: PMC4047956 DOI: 10.1016/j.ijppaw.2014.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 02/14/2014] [Accepted: 02/17/2014] [Indexed: 12/20/2022]
Abstract
Morphological and molecular characterisation for nine myxosporeans is provided. Comparison of myxosporean diversity from the Arctic with other regions is performed. The taxon sampling of the marine urinary clade is markedly increased. Evolutionary trends within the marine urinary clade are discussed.
Myxosporeans (Myxozoa), microscopic metazoan parasitic organisms, are poorly studied in the Arctic region. Our survey of benthic and pelagic fish (n = 234) collected in Isfjorden (Svalbard, Norway) together with detailed morphological and molecular examination revealed the presence of nine myxosporean species. We compared observed myxosporean diversity with diversity documented in regions close to the Arctic and revealed that water depth rather than geographic distribution is an important factor influencing myxosporean fauna. We describe three new myxosporean species: Zschokkella siegfriedi n. sp. from kidney of Boreogadus saida, Parvicapsula petuniae n. sp. from the urinary bladder of Gymnocanthus tricuspis, and Sinuolinea arctica n. sp. from the urinary bladder of Myoxocephalus scorpius. We characterise Latyspora-like organism from kidney of Clupea harengus. We provide new data for Ceratomyxa porrecta, Myxidium gadi, Myxidium finnmarchicum, Schulmania aenigmatosa, and Parvicapsula irregularis comb. nov. The phylogenetic analyses including the newly obtained SSU and LSU rDNA data revealed that most of the species studied cluster in the marine urinary clade within the marine myxosporean lineage. Newly obtained sequences including the first molecular data for the member of the genus Schulmania, substantially enriched the Zschokkella subclade. C. porrecta and the two Myxidium species cluster within the Ceratomyxa and marine Myxidium clade, respectively. Newly described species, Z. siegfriedi n. sp., was revealed to be morphologically indistinguishable but genetically diverse from Zschokkella hildae known from numerous gadid fish. Therefore, we consider Z. siegfriedi to be a cryptic myxosporean species that might be misidentified with Z. hildae. A Latyspora-like organism was found to be taxonomically problematic due to its suture line and its distant phylogenetic position from the type species Latyspora scomberomori did not allow us to assign it to the genus Latyspora. Based on an increased taxon sampling and SSU + LSU rDNA-based phylogeny, evolutionary trends within the marine urinary clade are investigated.
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Affiliation(s)
- Alena Kodádková
- Faculty of Science, University of South Bohemia in České Budějovice, Branišovská 31, 370 05 České Budějovice, Czech Republic ; Institute of Parasitology, Biology Centre of the Academy of Sciences of the Czech Republic, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Iva Dyková
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Tomáš Tyml
- Faculty of Science, University of South Bohemia in České Budějovice, Branišovská 31, 370 05 České Budějovice, Czech Republic ; Institute of Parasitology, Biology Centre of the Academy of Sciences of the Czech Republic, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Oleg Ditrich
- Faculty of Science, University of South Bohemia in České Budějovice, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Ivan Fiala
- Institute of Parasitology, Biology Centre of the Academy of Sciences of the Czech Republic, Branišovská 31, 370 05 České Budějovice, Czech Republic
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13
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Karlsbakk E, Einen ACB, Bartosová P. Sphaeromyxa artedielli sp. n. (Myxozoa: Sphaeromyxidae), a parasite of sculpins (Cottidae) in northern Norway. Folia Parasitol (Praha) 2014; 60:425-32. [PMID: 24471284 DOI: 10.14411/fp.2013.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Sphaeromyxa artedielli sp. n. is described from the gall bladder of the Atlantic hookear sculpin Artediellus atlanticus Jordan et Evermann (Cottidae; type host) from northern Norway. The parasite was also found to infect Triglops murrayi Günther (Cottidae). Spores are produced in disporic pansporoblasts in large flat plasmodia. Spores are straight and fusiform with truncated ends, and measure 16.5-18.7 microm x 4.9-6.2 microm. Valves are thick, striated and suture line is straight. Two equal ovoid polar capsules measure 4.2-6.8 microm x 2.9-4.4 microm and contain irregularly folded polar filaments. Distinctive features include spore shape and size, spore length/width relationship, striated valves, equal polar capsules and a short intercapsular distance. Sphaeromyxa bonaerensis Timi et Sardella, 1998, Sphaeromyxa cannolii Sears, Anderson et Greiner, 2011, and Sphaeromyxa sevastopoli Naidenova, 1970 produce straight spores with truncated ends that are of similar length as those of the new species. Sphaeromyxa cannolii differs in showing smooth spores with unequal polar capsules. The new species differs from S. bonaerensis and S. sevastopoli in significantly wider spores and polar capsules. Sphaeromyxa balbianii Thélohan, 1892, a species originally described with significantly smaller spores than S. artedielli sp. n., has previously been recorded from T. murrayi. We show that S. artedielli sp. n. differs from S. balbianii from the type host Gaidropsarus vulgaris (Cloquet) by its SSU rDNA sequence, and suggest that Atlantic records of Sphaeromyxa spp. from T. murrayi represent S. artedielli sp. n. The closest relative to S. artedielli sp. n. according to the SSU rDNA sequences, S. longa Dunkerly, 1921, differs clearly by spore size and shape. In the SSU rDNA-based phylogenetic analyses, S. artedielli sp. n. groups with other Sphaeromyxa spp. with straight spores and truncated ends in a clade that represents a sister-group to Sphaeromyxa spp. with arcuate spores and rounded ends. Our results indicate that an SSU rDNA pseudogene is present in S. balbianii.
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Affiliation(s)
| | | | - Pavla Bartosová
- Institute of Parasitology, Biology Centre of the Academy of Sciences of the Czech Republic, Ceské Budĕjovice, Czech Republic
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