Immune Response Of Common Carp Research Articles

The role of TF-b in iron homeostasis and bacterial defense in common carp (Cyprinus carpio)

Transferrin (TF) is a prototypical biological macromolecule protein known for its iron-binding properties. TF proteins play a crucial role in modulating host iron homeostasis and defending against pathogen invasion. In this study, we utilized common carp (Cyprinus carpio) tissues and Epithelioma papulosum cyprinid (EPC) cells to establish experimental models of iron overload with FeCl3 or ferric amine citrate (FAC), and to establish experimental models of bacterial infection with Aeromonas hydrophila. The current research has successfully identified the CcTF-b gene in common carp, revealing an ORF of 2001 bp with N-terminal and C-terminal structures. CcTF-b exhibited inhibitory effects on the growth of LPS and LTA in vitro. In the experimental models, the upregulations of PTGS2a and PTGS2a-like mRNA and protein levels were observed. Overexpression or interference with CcTF-b levels can modulate the expression of ferroptosis-related genes, inflammatory cytokines, lipid reactive oxygen species, GSH/GSSH levels, and Fe2+ concentration. Significantly, the expression levels of Nrf2 and GPX4 mRNA and protein, as well as the bacterial load of A. hydrophila, could be also modulated either by upregulating or downregulating CcTF-b factors. In conclusion, in this study, these findings suggest that CcTF-b plays a critical role in the innate immune response of common carp.

Early mucosal responses in common carp (Cyprinus carpio) to the infection of Aeromonas hydrophila

Common carp (Cyprinus carpio), an economically important freshwater fish species, is worldwide farmed especially in Europe and Asia. The current high-density intensive rearing way leading to a high susceptibility to various pathogens, and Aeromonas hydrophila is one of the most frequently encountered bacteria, causing huge economic losses to the common carp industry. The mucosal barrier of fish constitutes the first line of defense against various pathogens, and some level of inter-connectivity exists among teleost mucosal tissues. However, the molecular basis for a common mucosal immune response at multiple sites or response at one site but during different timepoints following stimulation remains to be studied. In this study, we examined and systematically analyzed a total of 144 transcriptome files from three primary common carp mucosal tissues at four early timepoints following the infection of A. hydrophila. A total of 410 unigenes were significantly differentially expressed in all tested mucosal tissues. Through GO enrichment and KEGG pathway analysis, 28 key genes which might played critical roles in the common mucosal immune response of common carp during the early stage of bacterial infection were identified. Further WGCNA analysis showed that, besides the common response, three mucosal tissues exhibited tissue-specific gene regulatory network. Meanwhile, candidate hub genes in each tissue were identified, including trim3, rpl14, tln2, itpr1, and others. Our results will provide a fundamental basis for understanding the molecular mechanisms of teleost mucosal immunity, and might suggest strategies for developing novel teleost mucosal vaccines in aquaculture.

CcPTGS2a-like gene-mediated NF-κB/ERK signaling regulation in the common carp (Cyprinus carpio)

Prostaglandin-endoperoxide synthase 2 (PTGS2), a common biological macromolecule, is pivotal for innate immunity and pathogen recognition. In this study, we identified and characterized a CcPTGS2a-like gene in the common carp (Cyprinus carpio) with an open reading frame (ORF) of 1821 bp and epidermal growth factor and peroxidase domains. Our multiple sequence analysis revealed high homology between the amino acid sequence of CcPTGS2a-like and those of its homologs in other fish. CcPTGS2a-like mRNA and protein expressions were significantly upregulated in the spleen, head kidney, liver, and gill tissues upon exposure to Aeromonas hydrophila stimulation. CcPTGS2a-like protein recognized the conserved bacterial surface components and exhibited detectable bacterial binding activity. CcPTGS2a-like overexpression before exposure to A. hydrophila notably enhanced the survival rate of common carp, concomitant with decreased bacterial burden. The NF-κB/ERK signaling pathway initiated the immune response in common carp upon infection with A. hydrophila. CcPTGS2a-like overexpression or interference in the head kidney and Epithelioma papulosum cyprinid cells could modulate the p–NF–κB (p-p-65), p-IκBα, and p-ERK1/2 levels as well as the IL-1β and IL-6 mRNA expression. These results indicated potential CcPTGS2a-like involvement in the immune response of the common carp to bacterial infections through the NF-κB/ERK signaling pathway.

Selective autophagy receptor p62 promotes antibacterial and antiviral immunity in common carp (Cyprinus carpio)

Sequestosome 1 (SQSTM1/p62) is a selective autophagy adapter protein that participates in antiviral and bacterial immune responses and plays an important regulatory role in clearing the proteins to be degraded and maintaining intracellular protein homeostasis. In this study, two p62 genes were cloned from common carp (Cyprinus carpio), namely Ccp62-1 and Ccp62-2, and conducted bioinformatics analysis on them. The results showed that Ccp62s had the same structural domain (Phox and Bem1 domain, ZZ-type zinc finger domain, and ubiquitin-associated domain) as p62 from other species. Ccp62s were widely expressed in various tissues of fish, and highly expressed in immune organs such as gills, spleen, head kidney, etc. Subcellular localization study showed that they were mainly distributed in punctate aggregates in the cytoplasm. After stimulation with Aeromonas hydrophila and spring viraemia of carp virus (SVCV), the expression level of Ccp62s was generally up-regulated. Overexpression of Ccp62s in EPC cells could inhibit SVCV replication. Upon A. hydrophila challenge, the bacterial load in Ccp62s-overexpressing group was significantly reduced, the expression levels of pro-inflammatory cytokines and interferon factors were increased, and the survival rate of the fish was improved. These results indicated that Ccp62s were involved in the immune response of common carp to bacterial and viral infections.

Stressing out-carp edema virus induces stress and modulates immune response in common carp.

Carp edema virus (CEV) is a fish poxvirus that primarily infects the gills of common carp. CEV causes koi sleepy disease (KSD), which is highly contagious and can result in mortality of up to 100%. In the present study, we analyzed the stress and immune responses during KSD in two strains of common carp with different resistance to CEV: susceptible koi and resistant Amur sazan. Experiments were performed at two temperatures: 12°C and 18°C. In the case of koi carp, we also analyzed the effect of supplementation of 0.6% NaCl into tank water, which prevents mortality of the CEV-infected fish (salt rescue model). We found that CEV-infected koi kept at 18°C had the highest viral load, which correlated with the most severe histopathological changes in the gills. CEV infection resulted in the activation of stress response reflected by the upregulated expression of genes involved in stress response in the stress axis organs and increased levels of cortisol and glucose in the blood plasma. These changes were the most pronounced in CEV-infected koi kept at 18°C. At both temperatures, the activation of antiviral immune response was observed in koi kept under freshwater and NaCl conditions upon CEV infection. Interestingly, a clear downregulation of the expression of adaptive immune genes was observed in CEV-infected koi kept under freshwater at 18°C. CEV induces a stress response and modulates adaptive immune response in koi, and this is correlated with the level of viral load and disease development.

Probiotic Supplement Enhances the Hematological Parameters and Immune Response of Common Carp against Fish Pathogen Aeromonas hydrophila

Probiotic bacteria play an important role in the growth and health of aquatic animals by improving their immune system. A 60-day experiment study was carried out to evaluate the effect of probiotic bacteria Bacillus subtilis dietary supplement enhances the hematological parameters and Immune response of fish Common carp against the pathogenic Aeromonas hydrophila. The experimental fish with an average mean weight of 15.15 ± 1.05 g were distributed randomly into 3 groups (Control (CTRL (Basal feed and without A. hydrophila), Exp1 (Basal feed and with A. hydrophila, and Exp2 (108 CFU/ml with probiotic supplement with A. hydrophila). On the 56th day, experimental groups were then challenged with A. hydrophila (1.0 × 107 CFU/mL), after 72 hrs of infection, blood samples were collected randomly from five fish from each group. Results showed that probiotic supplementation improved Hematological parameters such as RBCs, WBCs, Hb, PCV, and Immune response parameters (Nitroblue Tetrazolium Activity, aminotransferase, Serum lysozyme activity, total protein, and immunoglobulin). This present study suggests that the probiotic diet enhances the disease resistance against Aeromonas hydrophila in the culture of Common carp.

Season affects the estrogen system and the immune response of common carp.

The physiology of ectothermic animals, including fish, is strictly regulated by season-related external factors such as temperature or photoperiod. The immune response and the production of hormones, such as estrogens, are therefore also subject to seasonal changes.This study in common carp aimed to determine how the season affects the estrogen system and the immune response, including the antibacterial response during Aeromonas salmonicida infection. We compared the immune reaction in spring and autumn in the head kidney and liver and found that carp have higher levels of blood 17β-estradiol in autumn, while in the liver of these fish there is a higher constitutive expression of genes encoding vitellogenin, estrogen receptors and Cyp19 aromatase than in spring. Fish sampled in autumn also exhibited higher expression of immune-related genes in the liver. In contrast, in the head kidney from fish sampled in the autumn, the expression of genes encoding estrogen receptors and aromatase was lower than in spring, and a similar profile of expression was also measured in the head kidney for inos, arginases and il-10. In turn, during bacterial infection, we observed higher upregulation of the expression of inos, il-12p35, ifnγ-2, arginase 2 and il-10 in the liver of carp sampled in spring. In the liver of carp infected in spring a higher upregulation of the expression of the genes encoding CRPs was observed compared to fish infected during autumn. The opposite trend occurred in the head kidney, where the upregulation of the expression of the genes involved in the immune response was higher in fish infected in autumn than in those infected in spring. During the infection, also season-dependent changes occurred in the estrogen system.In conclusion, we demonstrated that season differentially affects the estrogenic and immune activity of the head kidney and liver. These results reinforce our previous findings that the endocrine and immune systems cooperate in maintaining homeostasis and fighting infection.

Effects of Multispecies Probiotic Combination on Growth Performance, Biochemical Indices, and Non-specific Immune Responses in Common Carp (Cyprinus carpio)

Background: Probiotic bacteria as an alternative to antibiotics are necessary for aquaculture due to the prevalence of recurrent diseases. Objectives: This study investigated the effect of a probiotic combination, including endogenous bacteria such as Lactobacillus plantarum, Lactobacillus bulgaricus, Lactobacillus acidophilus, and Lactobacillus rhamnosus, on the health status of common carp. Methods: The probiotic combination was added to carp basal diets in three treatments, 1 to 3, each containing 106 CFU g-1, 107 CFU g-1, and 108 CFU g-1 probiotic combination, respectively. A fourth group (group 4) was used as a control and received no probiotic treatment for six months. After 3 months, the fish’s growth performance, biochemical indices, and innate immune responses were evaluated. Results: The growth indices, such as the daily growth rate, specific growth rate, condition conversion factor, condition factor, and protein efficiency, significantly improved in treatments 2 and 3 compared to the other groups (P < 0.05). Investigation of complement, lysozyme, and serum bactericidal activity showed that probiotic treatments positively affected the immune system of common carp, with treatments 2 and 3 demonstrating a greater effect (P < 0.05). Biochemical factors were also investigated, showing decreased cholesterol and triglyceride levels in the probiotic treatment group. Moreover, the probiotic treatments resulted in a significant reduction in the activity of liver enzymes AST and ALP compared to the control group (P < 0.05). Conclusions: A probiotic combination with concentrations of 5 × 107 CFU g-1 and 5 × 108 CFU g-1 of food can positively impact common carp’s growth performance, immune system, and biochemical parameters. As no significant difference was seen between the two concentrations, the lower one is recommended.

Effect of Beneficial Colonization of Bacillus coagulans NRS 609 on Growth Performance, Intestinal Health, Antioxidant Capacity, and Immune Response of Common Carp (Cyprinus carpio L.)

This study is aimed at exploring the effects of Bacillus coagulans NRS 609 on the growth performance, intestinal health, antioxidant activity, and immune response in common carp (Cyprinus carpio L.) by colonizing the intestinal tract with the beneficial strain. Gavage B. coagulans with GFP-tag at 109 CFU/mL into common carp for 7 days. Results indicated that B. coagulans were maintained in the intestine for at least 14 days. Four groups fed B. coagulans at different levels of inclusion, including 0 (CK), 1 × 10 7 (A), 1 × 10 8 (B), and 1 × 10 9 (C) CFU/g of feed for 8 weeks. Experimental groups showed significantly better growth performance than the control ( P < 0.05 ). The treatment groups had higher digestive enzyme activity, villus height, and muscle thickness than the control ( P < 0.05 ). Supplementation with B. coagulans also altered the composition of the intestinal flora. In addition, an enhancement of the antioxidant enzyme and a reduction of malondialdehyde in the liver were observed with the addition of B. coagulans ( P < 0.05 ). Moreover, the cytokines of IL-1β and IL-12, IL-10, and TGF-β, significant upregulation in experimental groups ( P < 0.05 ). Based on the results, the optimal level of B. coagulans was 107 CFU/g in diets for common carp.

Improved immune response of common carp (Cyprinus carpio) by administration of mahang sirap (Macaranga involucrate) Leaf Extract

This study aims to test the effectiveness of Macaranga involucrata leaf extract as an immune response in carp to increase the number of leukocytes and phagocytic activity. M. involucrata extract was injected intramuscularly into carp. The method used is Completely Randomized Design (CRD). This study was conducted with five treatments, each of which was repeated three times. The treatments were P1 = 1% (v/v), P2 = 4% (v/v), P3 = 8% (v/v), P4 = 12% (v/v) and P5 (negative control). The results showed that M. involucrata extract could respond to an increase in the number of leukocytes and an increase in phagocytic activity. Responses to an increase in the number of leukocytes (12.27 x 108 cells/mL) and phagocytic activity (45.41%) were found in P4 treatment. Based on this study it was concluded that M. involucrata extract showed an increase in the immune response of carp.

Negative regulation of interferon regulatory factor 6 (IRF6) in interferon and NF-κB signalling pathways of common carp (Cyprinus carpio L.)

BackgroundInterferon (IFN) regulatory factors (IRFs) is a kind of transcription factors, which play an important role in regulating the expression of type I IFN and related genes. In mammals, IRF6 is not relevant with IFN expression, while zebrafish IRF6 was reported to be a positive regulator of IFN expression and could be phosphorylated by both MyD88 and TBK1. However, the role of IRF6 in the immune response and IFN transcription of common carp is unknown.ResultsIn the present study, the cDNA of IRF6 gene (CcIRF6) was cloned from common carp using RACE technique, with a total length of 1905 bp, encoding 471 amino acid residues, which possesses two functional domains of DBD and IAD. Similarity analysis showed that CcIRF6 had more than 50% similarity with IRFs of other vertebrates, and had the highest similarity with grass carp and zebrafish, among which the DBD domain was much more conserved. The phylogenetic analysis showed that CcIRF6 is in the branch of Osteichthyes and has the closest relationship with grass carp. In healthy common carp, the CcIRF6 was expressed in all the examined tissues, with the highest level in the oral epithelium, and the lowest level in the head kidney. After intraperitoneal injection of poly(I:C) or Aeromonas hydrophila, the expression of CcIRF6 increased in spleen, head kidney, foregut and hindgut of common carp. Moreover, poly(I:C), LPS, PGN and flagellin induced the expression of CcIRF6 in peripheral leukocytes and head kidney leukocytes of common carp in vitro. In EPC cells, CcIRF6 inhibited the expression of some IFN-related genes and pro-inflammatory cytokines, and dual luciferase reporter assay showed that CcIRF6 reduced the activity of IFN and NF-κB reporter genes.ConclusionsThe present study suggests that CcIRF6 is involved in the antiviral and antibacterial immune response of common carp, and negatively regulate the expression of IFN and NF-κB signalling pathways, which provides a theoretical basis for the study and prevention of fish disease pathogenesis.

Identification of three inflammatory Caspases in common carp (Cyprinus carpio L.) and its role in immune response against bacterial infection

Inflammatory Caspases are key effectors of the inflammasomes and play an important role in innate immune response. However, there are few studies on the homologs of inflammatory Caspases in bony fish. In the present study, three inflammatory Caspase genes were cloned from common carp and named CcCaspase-A1, CcCaspase-A2 and CcCaspase-B. Nucleotide sequences alignment revealed that the three Caspases were very similar in structure, which contained a PYD domain in the N-terminal, and a CASc domain in the C-terminal. In the phylogenetic tree, CcCaspase-A1 and CcCaspase-A2 were close to the Caspase-A of grass carp, and CcCaspase-B was close to the DrCaspase-B of zebrafish. In healthy common carp, the expression levels of CcCaspase-A1 and CcCaspase-A2 were the highest in the gills, and CcCaspase-B was the highest in the spleen. After immune stimulation with Edwardsiella tarda or Aeromonas hydrophila, the expression levels of all CcCaspases increased significantly. The fluorescence localization assays showed that all these CcCaspases were expressed in the cytoplasm, and were involved in the assembly of CcNLRP1 inflammasome. These results suggest that the inflammatory CcCaspases play a key role in immune response of common carp against bacterial infection, which may enrich the knowledge of inflammasome in fish, and provide basic data for the prevention and treatment of fish infectious diseases.

Effect of dietary β-mannanase supplementation on growth performance, digestibility, and gene expression levels of Cyprinus carpio (Linnaeus) fingerlings fed a plant protein-rich diet.

The aim of this study was to assess possible beneficial effects of dietary β-mannanase supplementation on the nutrient digestibility, growth performance, digestive and metabolic enzyme activity, and immune response of common carp (Cyprinus carpio) fed plant protein-rich diets. An experiment was conducted in triplicate, and a total of 225 fingerlings of common carp with an average body weight of 13.17 ± 0.12 g were stocked in 15 fiberglass tanks (15 fish/tank). Five dietary treatments (control 35% crude protein, plant-rich basal diet without supplement and four diets supplemented with β-mannanase from two sources (commercially available and locally isolated), each at two dosage levels (500 and 1,000 U/kg diet) were prepared and fed to respective groups of fish, twice a day (8:00 AM and 4:00 PM) at 4 % body weight. During the trial, changes in the level of DO and temperature ranged from 5.5 to 6.1 mg L−1 and 21.5 to 23.5°C, respectively. At the end of the feeding experiment, all fish in each tank were weighed and counted to determine growth parameters, while for the study of other indices, nine samples/treatment group were selected. The results of the study indicated a positive effect of both sources and dosage levels of β-mannanase supplementation on all studied indices, that is, significantly improved (P < 0.05), growth performance (%weight gain, specific growth rate), survival %, hematological indices (RBC, Hb, HCT, and MCHC), immunological indices (lysozyme activity, WBC, respiratory burst activity, and phagocytic activity), improved apparent digestibility of nutrients (crude protein, crude fat, and carbohydrates), and digestible energy. Furthermore, higher activity (P < 0.05) of the digestive enzymes (cellulase, lipase, and protease) and upregulation of MyoD gene in muscle and TNF-α gene in liver, intestine, and muscle were also observed, while the activity of serum AST (serum aspartate aminotransferase) and ALT (alanine transaminase) as compared to control group was significantly decreased (P < 0.05). Based on the results, β-mannanase supplementation (500 U/kg) could be recommended for obtaining better carp production when low-cost plant protein-rich diets are used.

Hepatopancreas toxicity and immunotoxicity of a fungicide, pyraclostrobin, on common carp

Pyraclostrobin (PYR), a strobilurin fungicide, has been widely used to control fungal diseases, posing potential risk to aquatic organisms. However, the toxic effects of PYR to fish remained largely unknown. In this study, common carp (Cyprinus carpio L.) was exposed to environmentally relevant levels of PYR (0, 0.5 and 5.0 μg/L) for 30 days to assess its chronic toxicity and potential toxicity mechanism. The results showed that long-term exposure to PYR induced hepatopancreas damage as evident by increased in serum transaminase activities (AST and ALT). Moreover, PYR exposure remarkably enhanced the expressions of hsp70 and hsp90, decreased the levels of antioxidant enzymes and biomarkers and promoted the reactive oxygen species (H2O2 and O2‐) and MDA contents in carp hepatopancreas. PYR exposure also upregulated apoptosis-related genes (bax, apaf-1, caspase-3 and caspase-9) and reduced anti-apoptosis gene bcl-2 in fish hepatopancreas. Moreover, PYR exposure altered the expressions of inflammatory cytokines (IL-1β, IL-6, TNF-α and TGF-β) in the serum and hepatopancreas and the level of NF-κB p65 in the hepatopancreas. Further research indicated that PYR exposure markedly changed the levels of immune parameters (LYZ, C3, IgM, ACP and AKP) in the serum and/or hepatopancreas, indicating that chronic PYR exposure also has immunotoxicity on fish. Additionally, we found that PYR exposure upregulated p38 and jnk MAPK transcription levels, suggesting that MAPK may be play important role in PYR-induced apoptosis and inflammatory response in the hepatopancreas of common carp. In summary, PYR exposure induced oxidative stress, triggered apoptosis, inflammatory and immune response in common carp, which can help to elucidate the possible toxicity mechanism of PYR in fish.

TRIM25 inhibits spring viraemia of carp virus replication by positively regulating RIG-I signaling pathway in common carp (Cyprinus carpio L.)

Common carp (Cyprinus carpio L.) is one of the most widely cultivated fish in China. Spring viraemia of carp virus (SVCV) is a highly pathogenic virus and has often caused excessive losses in carp pond fisheries. Innate immune play important roles against virus infection. To better understand the immune response of common carp against SVCV infection, transcriptome analysis was performed using the Illumina Novaseq 6000 platform. It was showed that a total of 3953 differentially expressed unigenes were identified, and the RLR signaling pathway were significantly enriched after SVCV infection. Subsequently, the role of RLR signaling pathway in SVCV infection was studied. The results showed that common carp RIG-I (CcRIG-I) and TRIM25 (CcTRIM25) significantly decreased the replication of SVCV by inducing the phosphorylation of TBK1, IRF3 and p65 and the expression of ifn-1, viperin, isg15 and mx. Further studies illustrated that CcTRIM25 could positive regulate CcRIG-I mediated downstream signaling pathway. Finally, the mechanism of CcTRIM25 promoting CcRIG-I-mediated signaling was investigated. CcTRIM25 could interact with the caspase activation and recruitment domain (CARD) of CcRIG-I and promoted K63-linked polyubiquitination of CcRIG-I. Altogether, the study revealed a mechanism of CcTRIM25 regulating CcRIG-I mediated immune response in SVCV infection.

Activation of the NLRP1 inflammasome and its ligand recognition in the antibacterial immune response of common carp (Cyprinus carpio)

NLRP1 (NLR family pyrin domain containing 1) is the first member of NOD-like receptors (NLRs) which can form inflammasome and play critical roles in innate immunity and pathogenesis of various diseases. To date, many NLRs and inflammasome-related genes have been identified in teleost, however, the activation of NLRP1 inflammasome is only found in zebrafish, and the activator of fish NLRP1 is unclear. In the present study, the activation of CcNLRP1 inflammasome and its function in innate immune defence of common carp was investigated. The expression of CcNLRP1 was induced in immune-related tissues of common carp upon challenge with Edwardsiella tarda and Aeromonas hydrophila. The colocalization of CcNLRP1 and CcASC, ASC oligomerization, and interaction between CcNLRP1CARD and CcASC was observed in 293T, Hela and EPC cells, suggesting that the CcNLRP1 inflammasome was activated in common carp. Furthermore, we found that MDP may be the specific ligand of CcNLRP1, which can activate the CcNLRP1 inflammasome. Taken together, the present study identifies a new inflammasome in common carp, and is beneficial to the control of infectious diseases in carp farming.

EFFICIENCY OF SYNBIOTIC AS FEED ADDITIVES ON GROWTH PERFORMANCE, SURVIVAL RATE AND HEALTH STATUS IN COMMON CARP CHALLENGED WITH SAPROLEGNIA SPP.

The present study was conducted to investigate the effects of Synbiotic (combination of probiotic and prebiotic) as feed additive on growth performance, survival rate and immune response against Saprolegnia spp. in common carp. A total of 100 C. carpio fingerlings, weighing 49.55–50.50 g were randomly distributed into five treatment groups in duplicate, fishes were fed with different concentrations as follows: (T1) 0.5 %, (T2)1.0 % ,(T3) 1.5 % and (T4 ) 2% as well as the control group were fed basal diet without any addition of synbiotic. Results showed significant increase (P&lt; 0.05) in all growth parameters (i.e. final weight, DWG, RGR, SGR (%), FCR, FCE) compared with the control group. The highest values were observed in fish fed on the diet containing 2% and 1.5% synbiotic. Also, survival rate recorded highest value (100%) in treatment supplemented with synbiotic 2% compared with control group (75%), suggesting that the high level (2%) improve growth rate and survival rate. At the end of experimental period six fish were randomly selected from each treatment and control (C) + for challenge test in a viable fungal suspension (1×105 live zoospores/ml) of Saprolegnia spp. Considerable changes have been observed in the mean values of WBCs. Respiratory burst activity showed significant increased in all synbiotic diet compared to C+ group. These results can be considered as a beneficial dietary for improving the growth rate and immune response in common carp.

Effects of Dietary Supplementation of PrimaLac, Inulin, and Biomin Imbo on Growth Performance, Antioxidant, and Innate Immune Responses of Common Carp (Cyprinus carpio)

Prebiotics, probiotics, and synbiotics have been successfully used in dietary supplements to achieve aquatic animal health and therefore increase the quality and sustainability of fish production. In the present study, four hundred and twenty common carps, Cyprinus carpio (25.37±0.22 g;mean±SE) were randomly attributed to seven treatments, fed with diets containing PrimaLac (probiotic), inulin (prebiotic), and Biomin Imbo (synbiotic), 1 and 2 g/kg for each supplement. After 60 days of feeding, an increase in final weight (FW), weight gain (WG), specific growth rate (SGR), and survival rate (SR) was recorded in the treatment groups compared to that of the control (P&lt;0.05). The food conversion ratio (FCR) in the treatment groups significantly decreased (P&lt;0.05). The treated groups showed significant improvements in serum immune parameters: lysozyme (LYZ), alternative complement (ACH50), total immunoglobulin (total Ig), and myeloperoxidase (MPO) (P&lt;0.05). Feeding fish with supplemented diets significantly showed enhanced antioxidant status: catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx). Malondialdehyde (MDA) activity was significantly lower in fish fed dietary additives (P&lt;0.05). Compared with the control group, enzyme parameters revealed that supplementation could significantly decrease alanine transaminase (ALT), alkaline phosphatase (ALP), and aspartate transaminase (AST) (P&lt;0.05). The biochemical parameters including triglyceride (TRIG), cholesterol (CHO), glucose (GLU), and cortisol (CORT) decreased with dietary supplementation (P&lt;0.05). Total protein (TP) increased in fish fed experimental diets (P&lt;0.05). Fish fed pro, pre, and synbiotic exhibited significantly higher digestive enzymes (amylase, lipase, and protease) (P&lt;0.05). Skin mucus parameters (total Ig, ACH50, LYZ, protease, and ALP) were significantly enhanced in groups fed dietary additives (P&lt;0.05). Thus, the best recommended inclusion level of supplementation is 2 g/kg for inulin and 2 g/kg for PrimaLac and doses of 1 or 2 g/kg for Biomin Imbo. Dietary PrimaLac, inulin, and Biomin Imbo could be recommended as beneficial feed additives to enhance growth performance, innate immune and antioxidant systems, and promoted biochemical parameters and digestion of common carp; also, the effect of dietary synbiotic was superior to that of prebiotic and probiotic.

The antioxidant responses of gills, intestines and livers and blood immunity of common carp (Cyprinus carpio) exposed to salinity and temperature stressors

Aquaculture activity is affected by various environmental factors, including water salinity and high temperatures. The present study investigated the impact of using varying water salinity (0, 5, 10, 15 and 20 ppt) on the growth behavior, immune responses and antioxidative responses of common carp. Fish were raised under optimal conditions except for water salinity for 8 weeks; fish were then subjected to high-temperature stress (32 °C) for 48 h. The results indicated a reduced final weight (FBW), weight gain (WG), specific growth rate (SGR), condition factor (CF), feed intake and feed efficiency ratio (FER) in common carp reared in 15 and 20 ppt (p < 0.05). The lowest FBW, WG, SGR, CF, feed intake and FER values were observed in fish reared in 20 ppt water salinity (p < 0.05). In gills, the superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were markedly decreased, but malondialdehyde (MDA) levels increased in fish challenged with 15 and 20 ppt before they were subjected to heat stress (p < 0.05). After heat stress, the SOD, CAT and GPx were decreased, and the MDA increased in fish reared in varying salinity levels (p < 0.05). Before heat stress, the intestinal SOD, CAT and GPx markers were decreased by 15 and 20 ppt, while the MDA level was increased by 15 and 20 ppt (p < 0.05). Generally, heat stress lowered the SOD, CAT and GPx activity in the intestines and liver tissues but increased MDA levels in common carp stressed by varying salinity levels (p < 0.05). The most decreased lysozyme activity, SOD, CAT and GPx and increased MDA levels were observed in common carp exposed to 20 ppt before and after heat stress (p < 0.05). After heat stress, fish exposed to 15 and 20 ppt had lower NBT than the remaining groups, and fish exposed to 20 ppt had the lowest values (p < 0.05). Overall, the heat stress markedly suppressed the antioxidant and immune responses of common carp reared in hypersalinity conditions.

EFFECTS OF EXTRACTS OF STOCHEOSPERMUM MARGINATUM AND ULVA LACTUCA ON THE HAEMATOLOGICAL AND IMMUNOLOGICAL PARAMETERS ON AEROMONAS HYDROPHILA INFECTED CYPRINUS CARPIO

Objective: Marine algae are the rich source of natural products with pharmacological and biological activities. In the present study the seaweeds Stocheospermum marginatum and Ulva lactuca extracts were used as a immuno stimulants of non-specific immune response in common carp were studied.&#x0D; Methods: The seaweeds Stocheospermum marginatum and Ulva lactuca chosen for the study and were extracted with ethanol. The fishes common carp (Cyprinus carpio) (weight 10±5g)] were divided into five groups. They were infected with A. hydrophila (1.6 × 104 CFU/fish). The infected fishes were injected with seaweeds extracts (0.30 mg) suspended in saline solution. One group was injected only saline (control) and one group was injected with ciprofloxacin (0.30 mg) (standard) suspended in saline. The experiment was carried out for 28 d. In every seven days interval the fishes were injected with seaweed extract and blood parameters of RBC, WBC, HB, Ht, MCV, MCH, and MCHC were recorded.&#x0D; Results: RBC was recorded on 28th day in group 3 (2.86±0.11×106 cells/mm3) followed by group 4 (2.13±0.04×106 cells/mm3). Similarly the WBC values also increase from initial day to final day.&#x0D; The phagocytic assay was same on 28th day in group 3 and group 4 (58.89±1.68). The lysozyme activity was more in group 3 on 28th day 1285±90.92 but the lowest activity recorded in group 4on 28th day 1205±34.35. The respiratory burst activity was higher in group 3 on 28th day 0.184±0.012. Overall results group 3 had the best activity when compared to others.&#x0D; Conclusion: From this study we can understand that the fish injected with seaweed extracts Stocheospermum marginatum and Ulva lactuca seweed as a good immunostimulant. The seaweeds Stoechospermum marginatum had alkaloids, phenol, quinone, saponin, steroid and terpenoid. Ulva lactuca containedalkaloids, sugar, flavenoid, phenol, quinone, steroid and terpenoid. These secondary metabolites were responsible for the immunostumilant activity.