Nucleospora cyclopteri n. sp., an intranuclear microsporidian infecting wild lumpfish, Cyclopterus lumpus L., in Icelandic waters

Particle and Fibre Toxicology

Árni Kristmundsson³  Jacob M Kasper²  Mark A Freeman¹ 

[1] Institute of Ocean and Earth Sciences, University of Malaya, Kuala Lumpur 50603, Malaysia;BioPol, Einbúastígur 2, 545, Skagaströnd, Iceland;Institute for Experimental Pathology, University of Iceland, Keldur v/Vesturlandsveg, 112, Reykjavik, Iceland

关键词: Kidney;    Clinical signs;    Lymphocyte;    Nucleospora;    Microsporidia;    Intranuclear;    Cyclopterus lumpus;    Lumpfish;   

Others  :  1228054
DOI  :  10.1186/1756-3305-6-49

 received in 2012-11-22, accepted in 2013-02-17,  发布年份 2013

【 摘 要 】

Background

Commercial fisheries of lumpfish Cyclopterus lumpus have been carried out in Iceland for centuries. Traditionally the most valuable part is the eggs which are harvested for use as a caviar substitute.

Previously reported parasitic infections from lumpfish include an undescribed intranuclear microsporidian associated with abnormal kidneys and mortalities in captive lumpfish in Canada. During Icelandic lumpfish fisheries in spring 2011, extensive enlargements to the kidneys were observed in some fish during processing. The aim of this study was to identify the pathogen responsible for these abnormalities.

Methods

Lumpfish from the Icelandic coast were examined for the causative agent of kidney enlargement. Fish were dissected and used in histological and molecular studies.

Results

Lumpfish, with various grades of clinical signs, were observed at 12 of the 43 sites sampled around Iceland. From a total of 77 fish examined, 18 had clear clinical signs, the most prominent of which was an extensive enlargement and pallor of the kidneys. The histopathology of the most severely affected fish consisted of extensive degeneration and necrosis of kidney tubules and vacuolar degeneration of the haematopoietic tissue. Intranuclear microsporidians were detected in all organs examined in fish with prominent clinical signs and most organs of apparently healthy fish using the new PCR and histological examination. One or multiple uniformly oval shaped spores measuring 3.12 ± 0.15 × 1.30 ± 0.12 μm were observed in the nucleus of affected lymphocytes and lymphocyte precursor cells. DNA sequencing provided a ribosomal DNA sequence that was strongly supported in phylogenetic analyses in a clade containing other microsporidian parasites from the Enterocytozoonidae, showing highest similarity to the intranuclear microsporidian Nucleospora salmonis.

Conclusions

Intranuclear microsporidian infections are common in wild caught lumpfish from around the Icelandic coast. Infections can cause severe clinical signs and extensive histopathological changes, but are also present, at lower levels, in fish that do not show clinical signs. Some common features exist with the intranuclear microsporidian previously reported from captive Canadian lumpfish, but DNA sequence data is required from Canadian fish to confirm conspecificity.

Based on phylogenetic analysis and the intranuclear location of the parasite, the name Nucleospora cyclopteri n. sp. is proposed.

【 授权许可】

   
2013 Freeman et al; licensee BioMed Central Ltd.

【 图 表 】

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【 参考文献 】

• [1]Ingolfsson A, Kristjánsson BK: Diet of juvenile lumpsucker Cyclopterus lumpus (cyclopteridae) in floating seaweed: effects of ontogeny and prey availability. Copeia 2002, 2:472-476.
• [2]Jónsson G: Íslenskir fiskar (Icelandic fishes). Reykjavik: Fjölvaútgáfan; 2003.
• [3]Thorsteinsson V: The ageing validation of the lumpsucker (Cyclopterus lumpus) and the age composition of the lumpsucker in Icelandic lumpsucker fisheries. [ http://www.hafro.is/Bokasafn/Greinar/ices_1981_G58.pdf webcite]
• [4]State of stocks 2011/2012 Prospects 2012/2013. Reykjavik: Marine Research Institute; 2012. [ http://www.hafro.is/Astand/2012/Astandsskyrsla_hafrannsoknastofnunarinnar_2012_lokaprentun.pdf webcite]
• [5]Mullins JE, Powell M, Speare DJ, Cawthorn R: An intranuclear microsporidian in lumpfish Cyclopterus lumpus. Dis Aquat Org 1994, 20:7-13.
• [6]Capella-Gutiérrez S, Marcet-Houben M, Gabaldón T: Phylogenomics supports microsporidia as the earliest diverging clade of sequenced fungi. BMC Biol 2012, 10:47. BioMed Central Full Text
• [7]Lom J, Dyková I: Microsporidia (Phylum Microspora). In Protozoan parasites of fishes. Development in Aquaculture and Fisheries Science. Amsterdam: Elsevier; 1992:125-157.
• [8]Freeman MA, Bell AS, Sommerville C: A hyperparasitic microsporidian infecting the salmon louse, Lepeophtheirus salmonis: an rDNA-based molecular phylogenetic study. J Fish Dis 2003, 26:667-676.
• [9]Palsson OK, Schopka SA, Stefansson G, Steinarsson BA: Icelandic groundfish survey data used to improve precision in stock assessments. J Northw Atl Fish Sci 1989, 9:53-72.
• [10]Vossbrinck CR, Baker MD, Didier ES, Debrunner-Vossbrinck BA, Shadduck JA: Ribosomal DNA sequences of Encephalitozoon hellem and Encephalitozoon cuniculi: species identification and phylogenetic construction. J Euk Microbiol 1993, 40:354-362.
• [11]Pomport-Castillon C, Romestand B, De Jonckheere JF: Identification and phylogenetic relationship of microsporidia by riboprinting. J Euk Microbiol 1997, 44:540-544.
• [12]Freeman MA, Yokoyama H, Ogawa K: A microsporidian parasite of the genus Spraguea in the nervous tissues of the Japanese anglerfish Lophius litulon. Folia Parasitol 2004, 51:167-176.
• [13]Zhang Z, Schwartz S, Wagner L, Miller W: A greedy algorithm for aligning DNA sequences. J Comput Biol 2000, 7:203-214.
• [14]Thompson JD, Gibson TJ, Plewniak F, Jeanmougin F, Higgins DG: The CLUSTAL-X windows interface: flexible strategies for multiple sequence alignment aided by quality analysis tools. Nucl Acids Res 1997, 24:4876-4882.
• [15]Hall TA: BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symp Ser 1999, 41:95-98.
• [16]Saitou N, Nei M: The neighbour-joining method: a new method for reconstructing phylogenetic trees. Mol Biol Evol 1987, 4:406-425.
• [17]Stentiford GD, Bateman KS, Dubuffet A, Chambers E, Stone DM: Hepatospora eriocheir (Wang and Chen, 2007) gen. et comb. nov. infecting invasive Chinese mitten crabs (Eriocheir sinensis) in Europe. J Invertebr Pathol 2011, 108:156-166.
• [18]Guindon S, Dufayard JF, Lefort V, Anisimov M, Hordijk W, Gascuel O: New algorithms and methods to estimate maximum-likelihood phylogenies: assessing the performance of PhyML 3.0. Syst Biol 2010, 59:307-321.
• [19]Ronquist F, Huelsenbeck JP, MrBayes 3: Bayesian phylogenetic inference under mixed models. Bioinformatics 2003, 19:1572-1574.
• [20]Nylander JAA, Ronquist F, Huelsenbeck JP, Nieves-Aldrey JL: Bayesian phylogenetic analysis of combined data. Syst Biol 2004, 53:47-67.
• [21]Gresoviac SJ, Khattra JS, Nadler SA, Kent ML, Devlin RH, Vivares CP, De La Fuente E, Hedrick RP: Comparison of small subunit ribosomal RNA gene and internal transcribed spacer sequences among isolates of the intranuclear microsporidian Nucleospora salmonis. J Eukaryot Microbiol 2000, 47:379-387.
• [22]Desportes I, Le Charpentier Y, Galian A, Bernard F, Cochand-Priollet B, Lavergne A, Ravisse P, Modigliani R: Occurrence of a new microsporidian: Enterocytozoon bieneusi n. g. n. sp. in the enterocytes of human patients with AIDS. J Protozool 1985, 32:250-254.
• [23]Sestak K, Aye PP, Buckholt M, Mansfield KG, Lackner AA, Tzipori S: Quantitative evaluation of Enterocytozoon bieneusi infection in simian immunodeficiency virus-infected rhesus monkeys. J Med Primatol 2003, 32:74-81.
• [24]Chilmonczyk S, Cox WT, Hedrick RP: Enterocytozoon salmonis n. sp.: an intranuclear microsporidium from salmonid fish. J Protozool 1991, 38:254-259.
• [25]Hedrick RP, Groff JM, Baxa DV: Experimental infections with Enterocytozoon salmonis Chilmonczyk, Cox, Hedrick (Microsporea): an intranuclear microsporidium from Chinook salmon Oncorhynchus tshawytscha. Dis Aquat Org 1991, 10:103-108.
• [26]Nilsen F, Ness A, Nylund A: Observations on an intranuclear microsporidian in lymphoblast from farmed Atlantic halibut larvae (Hippoglossus hippoglossus L.). J Eukaryot Microbiol 1995, 42:131-135.
• [27]Freeman MA, Sommerville C: Desmozoon lepeophtherii n. gen., n. sp., (Microsporidia: Enterocytozoonidae) infecting the salmon louse Lepeophtheirus salmonis (Copepoda: Caligidae). Parasit Vectors 2009, 2:58. BioMed Central Full Text
• [28]El Alaoui H, Grésoviac SJ, Vivarés C: Ocurrence of the microsporidian parasite Nucleospora salmonis in four species of salmonids from Massif Central of France. Folia Parasitol 2006, 53:37-43.
• [29]Hedrick RP, Groff JM, MacDowell TS, Willis M, Cox WT: Haematopoietic intranuclear microsporidian infections with features of leukemia in chinook salmon Oncorhynchus tshawytscha. Dis Aquat Org 1990, 8:189-197.
• [30]Morrison JK, MacConnell E, Chapman PF, Westgard RL: A microsporidium-induced lymphoblastosis in chinook salmon Oncorhynchus tshawytscha in freshwater. Dis Aquat Org 1990, 8:99-104.
• [31]Khattra JS, Gresoviac SJ, Kent ML, Myers MS, Hedrick RP, Devlin RH: Molecular detection and phylogenetic placement of a microsporidian from English sole (Pleuronectes vetulus) affected by X-cell pseudotumors. J Parasitol 2000, 86:867-871.
• [32]Lom J, Nilsen F: Fish microsporidia: fine structural diversity and phylogeny. Int J Parasitol 2003, 33:107-127.
• [33]Freeman MA, Sommerville C: Original observations of Desmozoon lepeophtherii, a microsporidian hyperparasite infecting the salmon louse Lepeophtheirus salmonis, and its subsequent detection by other researchers. Parasit Vectors 2011, 4:231. BioMed Central Full Text
• [34]Nylund S, Nylund A, Watanbe K, Arnesen CE, Karlsbakk E: Paranucleospora theridion n. gn., n. sp. (Microsporidia, Enterocytozoonidae) with a life cycle in the salmon louse (Lepeophtheirus salmonis, Copepoda) and Atlantic salmon (Salmo salar). J Eukaryot Microbiol 2010, 57:95-114.
• [35]Heuch PA, Øines Ø, Knutsen JA, Schram TA: Infection of wild fishes by the parasitic copepod Caligus elongatus on the south east coast of Norway. Dis Aquat Org 2007, 77:149-158.
• [36]Dunn AM, Smith JE: Microsporidian life cycles and diversity: the relationship between virulence and transmission. Microbes Infect 2001, 3:381-388.
• [37]Terry RS, Smith JE, Bouchon D, Rigaud T, Duncanson P, Sharpe RG, Dunn AM: Ultrastructural characterization and molecular taxonomic identification of Nosema granulosis n. sp., a transovarially transmitted feminizing (TTF) microsporidium. J Eukaryot Microbiol 1999, 46:492-499.
• [38]Bruno DW, Munro ALS: Observations on Renibacterium salmoninarum and the salmonid egg. Dis Aquat Org 1986, 1:83-87.
• [39]Haugland GT, Jakobsen RA, Vestvik N, Ulven K, Stokka L: Phagocytosis and respiratory burst activity in lumpsucker (Cyclopterus lumpus L.) leucocytes analysed by flow cytometry. PLoS One 2012, 7:10.