Abstract
Baltic cod livers have during recent years been found increasingly and heavily infected with third-stage larvae of Contracaecum osculatum. The infections are associated with an increasing population of grey seals which are final hosts for the parasite. Heavy worm burdens challenge utilization and safety of the fish liver products, and technological solutions for removal of worms are highly needed. We investigated the attachment of the worm larvae in liver tissue by use of histochemical techniques and found that the cod host encapsulates the worm larvae in layers of host cells (macrophages, fibroblasts) supported by enclosures of collagen and calcium. A series of incubation techniques, applying compounds targeting molecules in the capsule, were then tested for their effect to induce worm escape/release reactions. Full digestion solutions comprising pepsin, NaCl, HCl and water induced a fast escape of more than 60% of the worm larvae within 20 min and gave full release within 65 min but the liver tissue became highly dispersed. HCl alone, in concentrations of 48 and 72 mM, triggered a corresponding release of worm larvae with minor effect on liver integrity. A lower HCl concentration of 24 mM resulted in 80% release within 35 min. Water and physiological saline had no effect on worm release, and 1% pepsin in water elicited merely a weak escape reaction. In addition to the direct effect of acid on worm behaviour it is hypothesised that the acid effect on calcium carbonate in the encapsulation, with subsequent release of reaction products, may contribute to activation of C. osculatum larvae and induce escape reactions. Short-term pretreatment of infected cod liver and possibly other infected fish products, using low acid concentrations is suggested as part of a technological solution for worm clearance as low acid concentrations had limited macroscopic effect on liver integrity within 35 min.
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References
Bahlool QM, Skovgaard A, Kania PW, Buchmann K (2013) Effects of excretory/secretory products from Anisakis simplex (Nematoda) on immune gene expression in rainbow trout (Oncorhynchus mykiss). Fish Shellfish Immunol 35:734–739
Bier JW, Jackson GJ, Earl FL, Knollenberg WG (1976) Gross and microscopic pathology with larval Anisakis sp. and Phocanema Sp. nematodes from fish. Trans Am Microsc Soc 95:264–265
Boily F, Marcogliese D (1995) Geographical variations in abundance of larval anasakine nematodes in Atlantic cod (Gadus morhua) and American plaice (Hippoglossoides platessoides) from the gulf of St. Lawrence. Can J Fish Aquat Sci 52:105–115
Buchmann K (2007) An introduction to fish parasitological methods—classical and molecular techniques. Biofolia Publishers, Frederiksberg, pp 11–130
Buchmann K (2012) Fish immune responses against endoparasitic nematodes—experimental models. J Fish Dis 35:623–635
Buchmann K, Mehrdana F (2016) Effects of anisakid nematodes Anisakis simplex (s.l.), Pseudoterranova decipiens (s.l.) and Contracaecum osculatum (s.l.) on fish and consumer health. Food Waterb Parasitol 4:13–22
Chai YL, Murrell KD, Lymberry AJ (2005) Fish-borne parasitic zoonoses: status and issues. Int J Parasitol 35:1233–1254
Dezfuli BS, Fernandes CE, Galindo GM, Castaldelli G, Manera M, De Pasquale JA, Lorenzoni M, Bertin S, Giari L (2016a) Nematode infection in liver of the fish Gymnotus inaequilabiatus (Gymnotiformes: Gymnotidae) from the Pantanal region in Brazil: pathobiology and inflammatory response. Parasit Vectors 9:473. doi:10.1186/s13071-016-1772-2
Dezfuli BS, Manera M, Bosi G, De Pasquale JA, D’ Amelio S, Castaldelli G, Giari L (2016b) Anguilla anguilla intestinal immune response to natural infection with Contracaecum rudolphii A larvae. J Fish Dis 39:1187–1200
Eero M, Hjelm J, Behrens J, Buchmann K, Cardinale M, Casini M, Kirkegaard E, Horbowy J (2015) Eastern Baltic cod in distress: biological changes and challenges for stock assessment. ICES J Mar Sci 72(8):2180–2186
Fagerholm HP (1982) Parasites of fish in Finland. VI Nematodes. Acta Acad Aboen 40(6):5–128
Gay M, Bao M, MacKenzie K, Pascual S, Buchmann K, Bourgau O, Couvreur C, Mattiucci S, Paoletti M, Hastie LC, Levsen A, Pierce GJ (2017) Infection levels and species diversity of ascaridoid nematodes in Atlantic cod, Gadus morhua, are correlated with geographic area and fish size. Fish Res. doi:10.1016/j.fishres.2017.06.006
Godliauskienė R, Petraitis J, Jarmalaitė I, Naujalis E (2012) Analysis of dioxins, furans and DL-PCBs in food and feed samples from Lithuania and estimation of human intake. Food ChemToxicol 50(11):4169–4174
Haarder S, Kania P, Galatius A, Buchmann K (2014) Increased Contracaecum osculatum infection in Baltic cod (Gadus morhua) livers (1982–2012) associated with increasing grey seal (Halichoerus grypus) populations. J Wildl Dis 50:537–543
Horbowy J, Podolska M, Nadolna-Altyn K (2016) Increasing occurrence of anisakid nematodes in the liver cod (Gadus morhua) from the Baltic Sea: does infection affect the condition and mortality of fish? Fish Res 179:98–103
Kiernan JA (1990) Histological & Histochemical Methods: Theory & Practice, 2nd edn. Pergamon Press Ltd, Oxford
Køie M, Fagerholm HP (1995) The life cycle of Contracaecum osculatum (Rudolphi, 1802) sensu stricto (Nematoda, Ascaridoidea, Anisakidae) in view of experimental infections. Parasitol Res 81:481–489
Lin AH, Nepstad I, Floorvaag E, Egaas E, Van Do T (2014) An extended study of seroprevalence of anti-Anisakis simplex IgE antibodies in Norwegian blood donors. Scand J Immunol 79:61–67
Lunneryd SG, Bostrom MK, Aspholm PE (2015) Sealworm (Pseudoterranova decipiens) infection in grey seals (Halichoerus grypus), cod (Gadus morhua) and shorthorn sculpin (Myoxocephalus scorpius) in the Baltic Sea. Parasitol Res 114:257–264
Mattiucci S, Paggi L, Nascetti G, Ishikura H, Kikuchi K, Sato N, Cianchi R, Bullini L (1998) Allozyme and morphological identification of shape: Anisakis, Contracaecum and Pseudoterranova from Japanese waters (Nematoda, Ascaridoidea). Syst Parasitol 40(2):81–92
Mehrdana F, Buchmann K (2017) Excretory/secretory products of anisakid nematodes: biological and pathological roles. Acta Vet Scand 59(42):1–12
Mehrdana F, Bahlool QZM, Skov J, Marana MH, Sindberg D, Mundeling M, Overgaard BC, Korbut R, Strøm SB, Kania PW, Buchmann K (2014) Occurrence of zoonotic nematodes Pseudoterranova decipiens, Contracaecum osculatum and Anisakis simplex in cod (Gadus morhua) from the Baltic Sea. Vet Parasitol 205:581–587
Mehrdana F, Kania PW, Nazemi S, Buchmann K (2017) Immunomodulatory effects of excretory/secretory compounds from Contracaecum osculatum larvae in a zebrafish inflammation model. PLoS One 12(7):e0181277. doi:10.1371/journal.pone.0181277
Nadolna K, Podolska M (2014) Anisakid larvae in the liver of cod (Gadus morhua L.) from the Southern Baltic Sea. J Helminthol 88:237–246
Nadolna-Altyn K, Podolska M, Szostakowska B (2017) Great sandeel (Hyperoplus lanceolatus) as a putative transmitter of parasite Contracaecum osculatum (Nematoda: Anisakidae). Parasitol Res 116:1931–1936
Nagasawa K (2012) The biology of Contracaecum osculatum sensu lato and C. osculatum A (Nematoda: Anisakidae) in Japanese waters: a review. Biosph Sci 51:61–69
Perdiguero-Alonso D, Montero F, Raga JA, Kostadinova A (2008) Composition and structure of the parasite faunas of cod, Gadus morhua L. (Teleostei: Gadidae) in the North East Atlantic. Parasit Vectors 1:1–18
Schaum E, Müller W (1967) Die heterocheilidiasis. Eine Infektion des mensches mit Larven von Fisch Ascariden. Dtsch Med Wochenschr 92:2230–2233 (in German)
Shamsi S, Butcher AR (2011) First report of human anisakidosis in Australia. Med J Aust 194:199–200
Strøm SB, Haarder S, Korbut R, Mejer H, Thamsborg SM, Kania PW, Buchmann K (2015) Third-stage nematode larvae of Contracaecum osculatum from Baltic cod (Gadus morhua) elicit eosinophilic granulomatous reactions when penetrating the stomach mucosa of pigs. Parasitol Res 114:1217–1220
Zhu XQ, Podolska M, Liu JS., Yu HQ, Chen HH, Lin ZX, Lin RQ (2007) Identification of anisakid nematodes with zoonotic potential from Europe and China by single-strand conformation polymorphism analysis of nuclear ribosomal DNA. Parasitol Res 101(6):1703–1707
Zuo S, Huwer B, Bahlool Q, Al-Jubury A, Christensen ND, Korbut R, Kania P, Buchmann K (2016) Host size dependent anisakid infection in Baltic cod Gadus morhua associated with differential food preferences. Dis Aquat Org 120:69–75
Zuo S, Kania PW, Mehrdana F, Marana MH, Buchmann K (2017) Contracaecum osculatum and other anisakid nematodes in grey seals and cod in the Baltic sea: molecular and ecological links. J Helminthol 26:1–9. doi:10.1017/S0022149X17000025
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The present study was supported by the European Union’s Horizon 2020 research and innovation programme through the grant agreement No. 634429 (Parafishcontrol).
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Zuo, S., Barlaup, L., Mohammadkarami, A. et al. Extrusion of Contracaecum osculatum nematode larvae from the liver of cod (Gadus morhua). Parasitol Res 116, 2721–2726 (2017). https://doi.org/10.1007/s00436-017-5580-1
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DOI: https://doi.org/10.1007/s00436-017-5580-1