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1.
An experiment was conducted to determine the effect of Neoparamoeba sp. infection on the innate immune responses of Atlantic salmon. Atlantic salmon were experimentally infected with Neoparamoeba sp. and serially sampled 0, 1, 4, 6, 8 and 11 days post-exposure (dpe). Histological analysis of infected fish gill arches identified the presence of characteristic amoebic gill disease lesions as early as 1 dpe with a steady increase in the number of affected gill filaments over time. Immune parameters investigated were anterior kidney phagocyte function (respiratory burst, chemotaxis and phagocytosis) and total plasma protein and lysozyme. In comparison with non-exposed control fish basal respiratory burst responses were suppressed at 8 and 11 dpe, while phorbol myristate acetate-stimulated activity was significantly suppressed at 11 dpe. Variable differences in phagocytic activity and phagocytic rate following infection were identified. There was an increase in the chemotactic response of anterior kidney macrophages isolated from exposed fish relative to control fish at 8 dpe. Total protein and lysozyme levels were not affected by Neoparamoeba sp. exposure.  相似文献   

2.
Anterior kidney leucocytes obtained from Atlantic salmon, Salmo salar L., 2 days after administration of laminaran, were assayed for their capacity to reduce nitroblue tetrazolium to formazan, and for their activity of lysosomal acid phosphatase after intraperitoneal (15 mgkg?1), peroral (150 mg kg?1) or peranal (150 mg kg?1) administration. Leucocytes obtained from salmon treated by an intraperitoneal injection of laminaran produced significantly more superoxide anion than cells obtained from fish treated with dextran or sodium chloride immediately after cell isolation. Immediately after extraction, the activity of acid phosphatase in anterior kidney leucocytes obtained from salmon injected with laminaran was significantly higher than in cells harvested from fish treated with dextran or sodium chloride. Furthermore, cells obtained from salmon treated by peroral instillation of laminaran showed significantly enhanced production of superoxide anion compared with leucocytes from fish treated with either sodium chloride or dextran. The acid phosphatase activity in anterior kidney leucocytes from salmon treated by peroral and peranal instillation of laminaran was significantly higher than in cells from fish treated either with sodium chloride or dextran. Finally, fluorescence microscopic examination of tissue sections from fish treated peranally by intubation with fluorescein labelled laminaran revealed fluorescent vesicles in intestinal epithelial cells and in anterior kidney macrophages.  相似文献   

3.
Unmethylated CpG dinucleotides within bacterial DNA or synthetic oligodeoxynucleotides (ODNs) can activate immune cells. A panel of synthetic oligodeoxynucleotides was evaluated in vitro for their ability to enhance the innate immune response of common carp (Cyprinus carpio L.). In vitro addition of CpG-ODNs enhanced the phagocytic activity and superoxide anion production of stimulated kidney phagocytes. The CpG-ODNs also induced lymphocyte proliferation in the fish kidney cells. The ODNs containing multiple CpGs generally resulted in greater stimulatory capacity, although CpGs located at the terminus of an ODN were ineffective. These results indicated that CpG-ODNs enhance the innate immune response of common carp.  相似文献   

4.
Abstract. The stimulatory effect of LPS ( Vibrio anguillarum ), laminaran and sulphated laminaran, aqueous soluble β(1,6)-branched β(l,3)-D-glucan obtained from Laminaria hyperborea , on head kidney macrophages of Atlantic salmon, Salmo salar L., is reported. The macrophages, after stimulation with LPS or laminaran, showed pronounced spreading, membrane ruffling and increased organellc content when examined by light microscopy. LPS stimulation induced enhanced phagocytic and pinocytic activity, higher intraccllular production of superoxide anion, and higher activity of acid phosphatase compared to control cells. Native laminaran stimulated the cells to pinocytose more fluid phase, increase the intracellular production of superoxide anion and to elevate the activity of acid phosphatase. Sulphated laminaran induced higher production of superoxide anion and higher activity of acid phosphatase by macrophages than in control cells.  相似文献   

5.
Previous studies have demonstrated that beta-glucans stimulate Atlantic salmon, Salmo salar L., head kidney macrophages both in vitro and in vivo and increase protection against various pathogens. Based on our previous work that showed potent immunostimulatory CpG motif-containing oligodeoxynucleotides increased resistance to amoebic gill disease (AGD), the present study investigated the immunostimulatory effects of three commercial beta-glucan-containing feeds and their ability to increase resistance to AGD. All three commercial beta-glucans were able to stimulate the respiratory burst activity of Atlantic salmon head kidney macrophages in vitro, albeit at different times and concentrations. However, dietary incorporation of the beta-glucans was unable to stimulate the in vivo respiratory burst activity of head kidney macrophages, or serum lysozyme production, and did not increase resistance against AGD. However, this trial showed for the first time that a small subpopulation of Atlantic salmon subjected to a severe AGD infection was able to resist becoming heavily infected and furthermore survive the challenge.  相似文献   

6.
Sea water-adapted Atlantic salmon, Salmo salar L., were given a 2-h bath in a 2.5 mg L−1 levamisole (as levamisole hydrochloride) solution in fresh-water. Following bathing, the fish were held in full salinity sea water for 2 weeks before being subjected to a number of immunological assays. Heightened activity of the nonspecific defence system was demonstrated by increases in phagocytic index, phagocytic capacity and phagocytic activity, increased levels of the reactive oxygen intermediate, superoxide anion, and an increased lytic activity of both the mucus and the serum. These results indicate that levamisole is effective in augmenting parts of the nonspecific defence system of Atlantic salmon. This is the first record of the use and efficacy of levamisole as an immunomodulator in Atlantic salmon.  相似文献   

7.
As the supply of marine fish oil is becoming a limiting factor in the production of Atlantic salmon (Salmo salar), new diets and alternative sources of energy are being tested. Plant oils are natural potential candidates to replace fish oil, but the different levels of essential polyunsaturated fatty acids may influence the health and growth of salmon. In this study, we have investigated the resistance to transport stress and bacterial infection, phagocytic activity in head kidney macrophages and eicosanoid metabolism in salmon fed three different diets. In high-energy fishmeal based diets, 50% and 100% of the supplementary fish oil (FO) was replaced with soybean oil (SO). The three dietary groups were fed for 950 day-degrees at 5 °C (27 weeks) and 12 °C (11 weeks) before challenging the fish with Aeromonas salmonicida, analyzing the lipid composition of head kidney and examining macrophage function in vivo and in vitro. Dietary fatty acids affected the lipid composition of the kidney. The level of eicosanoid precursor’s 20:4n-6 and 20:3n-6 were 3 and 7-fold higher in the 100% SO group compared with the FO group. The total fraction of n-3 lipids in kidney was 19% in the SO group, compared to 16% and 12% in the 50% or 100% SO groups, respectively. However, the production of leucotriene B4 (LTB) and prostaglandin E2 (PGE) immunoreactive materiel from exogenously added arachidonic acid in head kidney macrophages was only affected by the composite diet (increased) at 5 °C. In addition, the phagocytic activity of kidney macrophages in vivo and in vitro was not affected by diet. No effect of diet was observed on transport stress or susceptibility to a bacterial infection with Aeromonas salmonicida. Atlantic salmon therefore seems to tolerate a diet solely based on soybean oil as lipid source, without any detrimental effects on growth, health and immune functions.  相似文献   

8.
Laminarin is a β‐glucan from the brown algae Laminaria digitata (J.V. Lamour), which can activate innate immune responses. With the aim of developing a strategy to evaluate specific phenotypical parameters of the effects of laminarin in trout innate immunity, we (i) fed fish with laminarin‐supplemented diet (0.2 g kg?1 day?1) for 21 days and (ii) treated fish with a single dose of intraperitoneal injected laminarin (0.08 g kg?1 fish). The evaluation of cellular and humoral immune parameters was established at phenotypic level by the phagocytic activity of headkidney macrophages and detection of inflammatory cytokines in head kidney and gill tissue by indirect ELISA. Results showed that both delivery methods of laminarin produce an increase in the phagocytic activity in head kidney macrophages and a significant increase in the production of TNFα and IL‐8 in gill tissue at day 21. Additionally, some of these parameters were significantly correlated (P < 0.025), which places them as new potential combined markers to detect activation of trout defense mechanisms by laminarin. These results highlight the importance of developing new protocols to quantitate immune parameters, in order to evaluate immunostimulants in fish farming.  相似文献   

9.
Duplicate groups of three genetic strains of Atlantic salmon smolts were cultured on diets containing either fish oil (FO) or a blend of vegetable oils (VO). Fatty acid compositions of liver and peripheral blood leucocytes were compared. The effect of different strains and diets on innate immune parameters and plasma prostaglandin E2 were also measured. Two strains were selected as being either 'fat' or 'lean' in terms of muscle adiposity. The third strain was a commercial stock (MH). Total replacement of dietary FO with VO resulted in reduced docosahexaenoic (DHA; 22:6 n -3) and eicosapentaenoic acids (EPA; 20:5 n -3) in liver, while oleic (18:1 n -9), linoleic (18:2 n -6) and α-linolenic (18:3 n -3) acids were all increased in VO-fed fish. Fatty acid compositions of blood leucocytes showed similar changes. Evaluation of innate immune function showed that in the fat strain, circulating leucocytes were significantly lower in VO fish. The lean strain also had significantly higher serum lysozyme activity than MH fish. Reduced haematocrit was seen in VO lean fish compared with FO lean fish. This study provides evidence of strain-induced differences in liver and leucocyte fatty acid compositions and innate immunity in Atlantic salmon fed either FO- or VO-based diets.  相似文献   

10.
Atlantic salmon, Salmo salar L., (14 g) were fed a practical fish-meal-based diet supplemented with 0. 10, 20. 40, 80 and 160 mg pyridoxine (PN) per kg feed for 20 weeks. Tissue vitamin B6 contents were significantly reduced in fish fed the non-supplemented diet compared with fish fed PN-supplemented diets. Serum haemolytic complement activity and head kidney lysozyme activity, and the specific antibody response following immunization with Vibrio salmonicida. were not influenced by the dietary regimes. Challenge with Aeromonas salmonicida showed that increasing the dietary levels of vitamin B6 did not improve the resistance to furunculosis. Growth, mortality and haematology were not affected by supplementing a practical diet with vitamin B6 In conclusion, feed levels of vitamin B6 higher than the minimum dietary requirement did not enhance immune functions and disease resistance in Atlantic salmon.  相似文献   

11.
Nucleotides from yeast RNA were evaluated for their ability to enhance the non-specific immune responses in carp, Cyprinus carpio . Oral administration of nucleotides to fish daily for 3 days resulted in enhanced responses of phagocytic and nitroblue tetrazolium (NBT) activities in kidney phagocytic cells. This activation of kidney cells was observed for at least 10 days post-treatment. The serum complement and lysozyme activities also increased in fish treated with nucleotides. Furthermore, the number of Aeromonas hydrophila in nucleotide-treated fish significantly decreased in the blood, kidney and liver after intraperitoneal injection. Thus yeast nucleotides appear to enhance non-specific immune responses in fish.  相似文献   

12.
13.
An analysis of the immune activity of herbal extract in vivo and in vitro assays was performed to explore the feasibility of using primary shrimp hemocyte culture to screen herbal immunostimulants. In vitro experiment was conducted by adding herbal extract into the medium of primary cultured hemocytes and incubating for 24h. In vivo experiment was carried out by feeding shrimp with diets incorporated with herbal extract for 21 days. Challenge test can be used to directly reflect comprehensive immune capacity of organisms. Four immune indexes, total hemocyte counts (THC and lysozyme, phenoloxidase (PO), and phagocytic activity were examined both in vitro and in vivo. The results showed that effects of herbal extract on THC or lysozyme activity were different between in vitro and in vivo. On the contrary, effects of herbal extract on PO activity and phagocytic activity in vitro and in vivo showed a strong correlation. Herbal extract, which enhanced PO activity and phagocytic activity in vitro, had ultimate immune-promoting function in vivo. Therefore, it was feasible to use primary hemocyte culture to screen herbal immunostimulants by determining the effects of herbal immunostimulants on PO and phagocytic activities.  相似文献   

14.
Head kidney macrophages from Atlantic cod, Gadus morhua L., were isolated by density sedimentation and maintained under serum-free conditions for up to one week. The cells adhered and spread well on glass and plastic, were highly phagocytic, and had typical macrophage morphology as shown by phase contrast and scanning and transmission electron microscopy. Histochemical studies with the light microscope showed that the macrophages were acid phosphatase and non-specific esterase positive, and alkaline phosphatase and peroxidase negative. Compared with unstimulated control cells, LPS-treated cells showed enhanced superoxide anion formation, as measured by the reduction of nitroblue tetrazolium, and increased levels of acid phosphatase activity.  相似文献   

15.
16.
Atlantic salmon (Salmo salar) were fed 6 experimental diets containing three levels of arachidonic acid (ARA) (0.18 g kg?1, 0.28 g kg?1 and 0.63 g kg?1 for low, medium and high levels, respectively) and two levels of vitamin E (150 and 730 mg kg?1 for low and high levels, respectively). At the end of the experimental period, fatty acids in the liver and immunity markers (lysozyme activity, respiratory burst and phagocytic activity) were determined and fish subjected to a challenge test against the salmonid rickettsial syndrome (SRS) pathogen. ARA, vitamin E or their interaction did not exert an effect on fish performance, whereas ARA alone clearly increased the deposition of ARA. Dietary vitamin E only enhanced liver vitamin E deposition, while the interaction of ARA and vitamin E influenced lysozyme activity and EPA/ARA ratio pointing out the effect of both nutrients on the fish immune system and metabolism. Only the medium concentration contributed to reducing mortality when the fish were exposed to the SRS pathogen. In conclusion, different levels of supplementation with ARA and vitamin E in the diet had no effect on productivity, but did have effects on immune markers and cumulative mortality when fish were exposed to the SRS pathogen.  相似文献   

17.
The study was to determine the effect of long-term administration of different dosages of levamisole on growth, immune response and disease resistance against Aeromonas hydrophila & Edwardsiella tarda in Labeo rohita fingerlings. Fish were fed with four different dosages of levamisole (0, 125, 250 and 500 mg kg−1 diet) for 56 days. Different serum biochemical and haematological parameters such as serum total protein content, albumin content, globulin content, albumin/globulin ratio, glucose content, leucocytes count; cellular immune parameters including superoxide anion production, phagocytic activities, lymphokine production index; humoural immune parameters including lysozyme, complement and serum bactericidal activities were evaluated after 14 days interval. After 56 days, fish were divided into two subgroups under each treatment group for challenge with pathogens A. hydrophila and E. tarda . The cumulative mortality (%) and agglutinating antibody titre was recorded on 28th day postchallenge. WBC count, phagocytic ratio, lymphokine production index, lysozyme activity and serum bactericidal activity were increased upon administration of levamisole dosages for long term. However, the growth performance and survival against pathogens was not significantly changed over 56 days administration of levamisole. But incorporation of moderate dosage of levamisole for 42 days results better immune response without effect on growth and survival of L. rohita fingerlings.  相似文献   

18.
The effect of aqueous extract of Cratoxylum formosum on innate immune response and disease resistance in tilapia Oreochromis niloticus was investigated. The fish were fed diets containing 0% (control), 0.5% (diet 1), 1% (diet 2), and 1.5% (diet 3) of C. formosum aqueous extract for 30 days. At the end of the experimental period, parameters of innate immune response including phagocytosis of blood leukocytes, lysozyme activity in plasma, and respiratory bust activity were examined. Feeding the fish with diet 2 and diet 3 for 20 days enhanced phagocytic activity and for 30 days stimulated lysozyme and respiratory burst activities. Diet 1 increased the phagocytic activity at 30 days, but did not affect the other measured parameters. All parameters were not significantly changed (P > 0.05) in the control group throughout the experiment. Following 30 days of feeding, fish were infected with S. agalactiae. The cumulative mortalities of bacterial-infected tilapia that were fed diet 1, diet 2, and diet 3 were 56, 12, and 10%, respectively, compared with 85% in the control group. These results indicate that the aqueous extract of C. formosum may elevate the innate immune response and enhance disease resistance in tilapia.  相似文献   

19.
Presmolt Atlantic salmon were fed a fish meal based experimental diet supplemented with graded levels of ascorbate-2-monophosphate (AP), equivalent to 40, 400, 2000 and 4000 mg ascorbic acid (AA)/kg for 6 months prior to a bacterial challenge experiment. The liver AA concentration reflected the dietary intake of AP, but not linearly. Growth, hematology and acid phosphatase activity in zymosan stimulated macrophages were not affected by dietary AP. Serum hemolytic complement activity was higher in fish fed the highest AP level, but the variation was not significant. Production of specific antibodies was significantly higher in fish fed the highest AP level 11 and 17 weeks after vaccination. Bacterial challenge with Aeromonas salmonicida showed increased survival in the 4000 AP group. Lysozyme activity in headkidney and serum complement activity and serum iron in fish surviving the challenge were higher in the 4000 AP group, indicating important roles of vitamin C on lysozyme, complement and iron in non-specific disease resistance. The results indicate that high dietary levels of AP favourably affect health in Atlantic salmon. Disease resistance was, however, not correlated with the AA status in the liver.  相似文献   

20.
免疫增强剂对河鲫鱼白细胞吞噬和溶菌酶活性的影响   总被引:2,自引:0,他引:2  
在饵料中添加不同含量的免疫增强剂(0.2%,0.5%,0.8%)连续投喂21d。在0,1,4,7,14,21d检测河鲫鱼(Carassius auratus)血液白细胞的吞噬活性、血清和体表粘液的溶菌酶活性。结果表明,该免疫增强剂可使河鲫鱼血液中白细胞吞噬活性、血清和体表粘液的溶菌酶活性都有明显提高。在停止投喂后7d,血清溶菌酶的活性逐渐降低与对照组无显著差异(P>0.05),但白细胞吞噬活性依然显著差异于对照组(P<0.05)。  相似文献   

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