title: Effect of heat-inactivated fish and non-fish derived probiotics on the innate immune parameters of a teleost fish (Sparus aurata L.).
abstract: The in vitro effects of four heat-inactivated bacterial species on the cellular innate immune responses of the gilthead seabream (Sparus aurata L.) were investigated. Head-kidney leucocytes were isolated and incubated for 30 min with two bacteria isolated from seabream skin (Pdp11 and 51M6; members of the Vibrionaceae and in the genus Shewanella) and two bacteria used as probiotics in humans and cattle (Lactobacillus delbrüeckii subsp. lactis and Bacillus subtilis) at 5 x 10(5), 5 x 10(6) or 5 x 10(7)CFU/ml. After incubation, different cellular innate immune parameters (leucocyte peroxidase content, phagocytosis, respiratory burst activity and cytotoxicity) were evaluated. The leucocyte peroxidase content was significantly higher after incubation with 51M6 at 5 x 10(7)CFU/ml. Head-kidney phagocytes were able to engulf the four bacterial species in all four cases, L. delbrüeckii subsp. lactis and B. subtilis being the most actively phagocytized. The incubation of seabream leucocytes with 51M6, L. delbrüeckii subsp. lactis and B. subtilis resulted in a great increase in respiratory burst activity. Cytotoxic activity was generally stimulated in a dose-dependent manner, the enhancement obtained with 5 x 10(7)CFU/ml being statistically significant. The usefulness of in vitro assays for screening and selecting candidate probiotic bacteria, as well as for optimising their effective dose, is discussed in relation with their immune-modulatory properties.
authors.affiliation: Fish Innate Immune System Group, Department of Cell Biology, Faculty of Biology, University of Murcia, Campus de Espinardo, 30100 Murcia, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Salinas
authors.forename: Patricia
authors.initials: P
authors.lastname: Díaz-Rosales
authors.forename: Alberto
authors.initials: A
authors.lastname: Cuesta
authors.forename: José
authors.initials: J
authors.lastname: Meseguer
authors.forename: Mariana
authors.initials: M
authors.lastname: Chabrillón
authors.forename: M Angel
authors.initials: MA
authors.lastname: Moriñigo
authors.forename: M Angeles
authors.initials: MA
authors.lastname: Esteban
mesh_terms: D001412:Bacillus subtilis / Q000276:immunology*; D003601:Cytotoxicity Tests, Immunologic / Q000662:veterinary; D005434:Flow Cytometry / Q000662:veterinary; D048668:Lactobacillus delbrueckii / Q000276:immunology*; D007962:Leukocytes / Q000201:enzymology / Q000276:immunology / Q000382:microbiology; D009195:Peroxidase / Q000032:analysis; D010587:Phagocytosis / Q000276:immunology; D019936:Probiotics / Q000494:pharmacology*; D016897:Respiratory Burst / Q000276:immunology; D021541:Sea Bream / Q000276:immunology*; D020592:Shewanella / Q000276:immunology*
chemical_list: D009195:Peroxidase