title: Protective effects of the prebiotic on the immunological indicators of rainbow trout (Oncorhynchus mykiss) infected with Aeromonas hydrophila.
abstract: The aim of this study was to investigate the protective effects of dietary administration of commercial prebiotic, Immunogen, on immunological indicators, enzymatic responses and stress tolerance in juvenile (81.65 ± 1.49) rainbow trout (Oncorhynchus mykiss) following Aeromonas hydrophila infection. The first group of fish was fed with the diet containing 2 g kg(-1) Immunogen whilst the control group received the diet free of Immunogen. There were three replicates per group. After 6 weeks feeding, the control group were divided into two treatments injected with saline buffer (control), and 1.5 × 10(8) CFU A. hydrophila respectively. The fish fed with the Immunogen supplemented diet were also injected with 1.5 × 10(8) CFU A. hydrophila. Our results revealed that dietary Immunogen increased the level of white blood cell (WBC) and percentage of lymphocyte (P < 0.05), however, the level of red blood cell (RBC), Hematocrit (Hct), hemoglobin (Hb) and percent of monocyte decreased in Untreated-Challenged group but unaffected in the group fed with Immunogen (P < 0.05). The level of lysozyme, alternative complement, antiprotease activity, total protein, albumin and globulin decreased in Untreated- Challenged group compared to control group. However, there was an increase in the level of lysozyme, alternative complement, antiprotease activity, bactericidal activity, in the Treated- Challenged group compared to other groups (P < 0.05). Serum alkali phosphatase (ALT) and aspartate aminotransferase, significantly increased fallowing challenge with A. hydrophila but in the Treated-Challenged group, there was no significant difference compared to the control group (P < 0.05). Lactate dehydrogenase (LDH) level was not different between groups (P > 0.05). Serum cortisol and glucose levels were higher in the challenge group, but these levels were lower in fish under challenge that were fed Immunogen-supplemented diet in contrast to the group fed control diet. The stress responses affected by A. hydrophila challenge (P < 0.05). Serum sodium, potassium and calcium concentration decreased by A. hydrophila exposure (P < 0.05), and Immunogen showed protection effect against this change.
authors.affiliation: Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Electronic address: p.yarahmadi@ut.ac.ir.
authors.forename: Peyman
authors.initials: P
authors.lastname: Yarahmadi
authors.affiliation: Young Reseasch and Elite Club, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran.
authors.forename: Hamed
authors.initials: H
authors.lastname: Ghafari Farsani
authors.affiliation: Department of Fisheries and Environmental Sciences, Faculty of Natural Resources, University of Tehran, Karaj, Iran.
authors.forename: Amin
authors.initials: A
authors.lastname: Khazaei
authors.affiliation: Department of Fisheries and Environmental Sciences, Faculty of Natural Resources, University of Tehran, Karaj, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Khodadadi
authors.affiliation: Department of Fisheries and Environmental Sciences, Faculty of Natural Resources, University of Tehran, Karaj, Iran.
authors.forename: Ghasem
authors.initials: G
authors.lastname: Rashidiyan
authors.affiliation: Center for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Victoria, Australia; Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
authors.forename: M Ali
authors.initials: MA
authors.lastname: Jalali
mesh_terms: D016980:Aeromonas hydrophila / Q000502:physiology; D000821:Animal Feed / Q000032:analysis; D000818:Animals; D004032:Diet / Q000662:veterinary; D060467:Disease Resistance; D005393:Fish Diseases / Q000276:immunology* / Q000382:microbiology; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D016905:Gram-Negative Bacterial Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D060226:Head Kidney / Q000276:immunology; D056724:Immunity, Humoral / Q000276:immunology*; D009113:Muramidase / Q000235:genetics / Q000378:metabolism; D017686:Oncorhynchus mykiss / Q000276:immunology*; D056692:Prebiotics; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
chemical_list: D029941:Fish Proteins; D018840:HSP70 Heat-Shock Proteins; D056692:Prebiotics; D014409:Tumor Necrosis Factor-alpha; D009113:Muramidase
keywords: Aeromonas hydrophila; Immunogen; Immunology; Physiological responses; Rainbow trout; Stress tolerance