title: Effects of Enteromyxum leei (Myxozoa) infection on gilthead sea bream (Sparus aurata) (Teleostei) intestinal mucus: glycoprotein profile and bacterial adhesion.
abstract: The intestinal myxosporean parasite Enteromyxum leei causes severe desquamative enteritis in gilthead sea bream (Sparus aurata) (Teleostei) that impairs nutrient absorption causing anorexia and cachexia. In fish, as in terrestrial vertebrates, intestinal goblet cells are responsible for the adherent mucus secretion overlying epithelial cells, which constitutes a first line of innate immune defense against offending microorganisms but serves also as substrate and nutrient source for the commensal microflora. The secreted intestinal mucus of parasitized (n = 6) and unexposed (n = 8) gilthead sea bream was isolated, concentrated, and subjected to downward gel chromatography. Carbohydrate and protein contents (via PAS and Bradford stainings), terminal glycosylation (via lectin ELISA), and Aeromonas hydrophila and Vibrio alginolyticus adhesion were analyzed for the isolated intestinal mucins. Parasitized fish, compared with unexposed fish, presented intestinal mucus mucins with a lower glycoprotein content and glycosylation degree at the anterior and middle intestine, whereas both glycoprotein content and glycosylation degree increased at the posterior intestine section, though only significantly for the total carbohydrate content. Additionally, a slight molecular size increase was detected in the mucin glycoproteins of parasitized fish. Terminal glycosylation of the mucus glycoproteins in parasitized fish pointed to an immature mucin secretion (N-acetyl-α-D-galactosamine increase, α-L-fucose, and neuraminic-acid-α-2-6-galactose reduction). Bacterial adhesion to large-sized mucus glycoproteins (>2,000 kDa) of parasitized fish was significantly lower than in unexposed fish.
authors.affiliation: Instituto de Acuicultura Torre de Sal, Consejo Superior de Investigaciones Científicas, Torre de Sal s/n, 12595 Ribera de Cabanes, Castellón, Spain. estensoro@iats.csic.es
authors.forename: Itziar
authors.initials: I
authors.lastname: Estensoro
authors.forename: Verena
authors.initials: V
authors.lastname: Jung-Schroers
authors.forename: Pilar
authors.initials: P
authors.lastname: Álvarez-Pellitero
authors.forename: Dieter
authors.initials: D
authors.lastname: Steinhagen
authors.forename: Ariadna
authors.initials: A
authors.lastname: Sitjà-Bobadilla
mesh_terms: D016980:Aeromonas hydrophila / Q000502:physiology; D000818:Animals; D001422:Bacterial Adhesion; D002850:Chromatography, Gel; D005393:Fish Diseases / Q000469:parasitology* / Q000473:pathology; D006023:Glycoproteins / Q000032:analysis*; D009093:Mucus / Q000737:chemistry* / Q000378:metabolism*; D055764:Myxozoa / Q000472:pathogenicity*; D010273:Parasitic Diseases, Animal / Q000469:parasitology* / Q000473:pathology; D021541:Sea Bream; D044149:Vibrio alginolyticus / Q000502:physiology
chemical_list: D006023:Glycoproteins; C047874:gastric mucus glycoproteins