title: Strong effect of long-term Sparicotyle chrysophrii infection on the cellular and innate immune responses of gilthead sea bream, Sparus aurata.
abstract: One thousand healthy recipient gilthead sea bream, Sparus aurata, cohabited with 250 donor fish parasitized by Sparicotyle chrysophrii (Van Beneden and Hesse, 1963) (Monogenea: Polyopisthocotylea), a common parasite of the gills of this fish species. Controls consisted of 1000 healthy fish kept in a separate tank. After 10 weeks, fish were weighed and parasite load, hemoglobin concentration and immunological parameters were assessed. Rather than the absence of parasite, hemoglobin concentration was a better marker of the health status of the fish, because S.chrysophrii had detached from the strongly anemic gills of some animals leaving fish with affected immune system but without parasites. The parasite infection seemed to trigger a cellular response of the fish immune system but to inhibit its humoral components. Thus, parasitized fish may control the parasite infection through the action of reactive oxygen species but they may become more sensitive to potential secondary bacterial or parasitical infections. This phenomenon was demonstrated not only through significant differences between recipient and control fish but also through strong correlations between those parameters and parasite load, fish weight and/or hemoglobin concentration.
authors.affiliation: Laboratory of Fish Nutrition and Pathology, Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Aghios Kosmas, Helliniko 16777, Greece. Electronic address: morgane@hcmr.gr.
authors.forename: M A
authors.initials: MA
authors.lastname: Henry
authors.affiliation: Laboratory of Fish Nutrition and Pathology, Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Aghios Kosmas, Helliniko 16777, Greece.
authors.forename: C
authors.initials: C
authors.lastname: Nikoloudaki
authors.affiliation: Laboratory of Fish Nutrition and Pathology, Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Aghios Kosmas, Helliniko 16777, Greece.
authors.forename: C
authors.initials: C
authors.lastname: Tsigenopoulos
authors.affiliation: Laboratory of Fish Nutrition and Pathology, Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Aghios Kosmas, Helliniko 16777, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Rigos
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001835:Body Weight / Q000276:immunology; D002590:Cestode Infections / Q000276:immunology*; D005880:Gills / Q000469:parasitology*; D006454:Hemoglobins / Q000378:metabolism*; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D007113:Immunity, Innate; D018836:Inflammation Mediators / Q000378:metabolism; D018384:Oxidative Stress; D059208:Parasite Load; D010986:Platyhelminths / Q000276:immunology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D021541:Sea Bream / Q000276:immunology*
chemical_list: D015415:Biomarkers; D006454:Hemoglobins; D018836:Inflammation Mediators; D017382:Reactive Oxygen Species
keywords: Antibody; Antiprotease activity; Ceruloplasmin; Complement; Lysozyme; Nitric oxide