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Stimulation of non-specific immune responses in Nile tilapia by seaweed-based natural compounds is a potential solution for the deterrence of Tilapia Lake Virus (TiLV) outbreaks. The present study investigated the protective and immunostimulatory effects of different seaweed extracts against TiLV. The study deals with hot water extracts of ten seaweeds in total namely Gracilaria edulis, Ulva fasciata, Caulerpa toxifolia, Turbinaria ornata, Enteromorpha compressa, Sargassum wightii, Sargassum ilicifolium, Sargassum muticum, Hynea musciformis and Chaetomorpha aerea collected from the Gulf of Mannar coast of Mandapam and Rameswaram, Tamil Nadu. Among these, extracts of three seaweeds such as S. ilicifolium, U. fasciata, and E. compressa exhibited notable antiviral effects by inhibiting cytopathic effect without cell toxicity in striped snakehead (SSN1) cell line. These seaweed extracts were further incorporated into artificial pellet feed at different concentrations (100, 300 and 500 mg/kg). Of which, tilapia fed with diet containing S. ilicifolium at 500 mg/kg of feed showed the highest RPS value (58.34%) followed by U. fasciata (50%) and E. compressa (41.67%). Additionally, significant (P < 0.05) improvements in haematological parameters, immunological parameters and immune gene expression were observed in the S. ilicifolium-fed group at 24, 48 and 72 h post-infection. The findings highlight S. ilicifolium extract as a natural dietary immunostimulant that enhances the health, productivity and management of TiLV in tilapia farming, promoting a sustainable approach to mitigate disease outbreaks in commercial aquaculture. [ABSTRACT FROM AUTHOR]

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A literature review on the use of immunostimulating additives in fish breeding has been carried out. The immunity of fish, especially in the early stages of development, directly affects survival and growth rate. And unfavorable environmental conditions: such as hydrochemical parameters of water, high temperature, low dissolved oxygen content and other factors can cause the appearance of invasive diseases and lead to the death of fish. The purpose of this study was to review the possibilities of using immunostimulating substances in aquaculture and the effectiveness of their use. The addition of biologically active substances to the diet of fish can increase productivity, give greater resistance to various diseases at the initial stages of ontogenesis, as well as improve the physiological state of the body as a whole. Many supplements not only provide better fish health, but also increase the growth rate and mass accumulation. In recent years, more and more attention has been paid to the use of plant components as immune enhancers for aquaculture facilities, replacing antibiotics and medicines.

Protein deficiency is a major difficulty for human needs in the past few decades, while different types of aquatic species are rich in high quality protein. Therefore, aquaculture is considered as the main developing food production sector globally. Bacterial infections are the main problem for aquaculture, and their outbreaks have a great impact on productivity, and previously indiscriminate use of antibiotics to control them. However, the emergence of multidrug-resistant pathogens might lead to sudden infectious disease outbreaks resulting in serious economic loss. Immunostimulants application is an effective technique to protect and enhance the immune system of aquatic animals and therefore improve aquaculture production. Nutrient immunostimulants such as essential fatty acids, amino acids, vitamins, and minerals are the most important responsibility to improve aquaculture production, as well as the cost of this method, which is effective, non-toxic, and environment friendly. These nutrient immunostimulants are supportive to increase the immune system, antioxidant, anti-inflammatory, and infection resistance of aquatic animals. In addition, nutritional feed additives improved feed palatability and the excellence of aquatic products and also enhance gut functions. Some information is available on nutrient immunostimulants in aquaculture applications, and this review provides information on different kinds of nutritional administration used in aquaculture to enhance positive impacts on aquatic animals’ health as well as feed quality development. This review will provide theoretical references for the application of nutrient immunostimulants in aquatic feeds.

Curcumin, a polyphenol, targets multiple signaling molecules and shows activity at the cellular level, supporting its various health benefits. Thereafter, the present study examines the effects of different doses of dietary curcumin on growth indices, feed efficiency, serum metabolites, redox (oxidation) status, immunity, histological assessment, and antioxidant-related genes in red tilapia (Oreochromis sp, Oreochromis aureus x O. mossambicus). A total of 1200 red tilapia with an average weight of 19.1±0.03 g were distributed in 12 cement ponds (3×3.5×1m). Each treatment was assigned three pounds (n=100 replicates). For 60 days, fish were fed baseline diets containing 0, 0.4, 0.6, and 0.8 g of curcumin/kg of diet. The treated fish showed increased body weight and SGR (specific growth rate) compared to the T0 group (P<0.05). Curcumin in the diet significantly improved weight gain, percentages, and FCR (feed conversion ratio), with a dose-dependent effect (P < 0.05). Curcumin supplementation showed no influence on feed intake, fish mortality, or survival rate (P >0.05). The curcumin-treated fish groups improved tissue structure in hepatocytes, pancreatic lumens, hepatic blood sinusoids, and intestine tissue layers, particularly the mucosal layer. The T0.8 group had reduced liver enzymes (AST and ALT) and greater total protein and albumin levels (P<0.05). The T0.6 and T0.8 groups showed significantly lower MDA levels than the other groups (P < 0.05). Curcumin groups demonstrated significantly higher antioxidant indices (CAT, GPx, and SOD) compared to the basal diet (P<0.05). Curcumin administration resulted in significant improvements in IgM and lysosome levels (P<0.05). All supplemented groups had considerably (P<0.05) higher levels of SOD, CAT, and GPx mRNA than the control group. Consequently, administering 0.6–0.8 g/kg of curcumin to red tilapia (Oreochromis sp.) diets may improve the fish's growth, health, tissue composition, and antioxidant response. [ABSTRACT FROM AUTHOR]

Immunosaccharides such as β-glucans and fructooligosaccharide (FOS) strengthen the host's immune responses. This study examined the influences of three levels of the β-1, 3 glucan-FOS combination on Red tilapia performance. Four diets were prepared: T0 as a control, while T0.5, T1, and T1.5 indicate the addition of β-1, 3 glucan-FOS mixture at 0.5%, 1%, and 1.5%, respectively. Then, 240 red Tilapia (Oreochromis niloticus x O. mossambicus) (weight 6.1 ± 0.07gm) were allocated into four groups, and every group was fed tested diets for 56 days. After the feeding trial, growth parameters, erythrogram profile, liver and kidney function testes, glucose, histopathological analysis, and gene expressions for antioxidants, catalase (CAT) and glutathione peroxidase (GPX) besides growth hormone (GH) and insulin-like growth factor 1 IGF1-related markers were assessed. Red tilapia fed T0.5, T1, and T1.5 exhibited consistent growth, survival rate, and homeostasis compared with the control group. Different supplement concentrations displayed varying levels of responses. The hepatorenal biomarkers (alanine transaminase (ALT = SGPT) and aspartate transaminase (AST = SGOT), alkaline phosphatase (ALP = ALK), urea, and creatinine) and glucose showed a significant reduction in the supplemented groups compared with the control, especially in the T1 and T1.5 groups. The intestinal morphometric study revealed that fish group fed on T1 represented the best result, whereas group T1.5, followed by group T0.5, was moderately treated, compared to the control. The real-time quantitative reverse transcription PCR (qRT-PCR) analysis displayed up-regulated expression of antioxidant and growth-correlated genes in the T1.5 groups. After 56 days, the β-1,3 glucan-FOS fed groups also exhibited an increase in survival rates compared to the control when challenged with a pathogenic Vibrio alginolyticus. Current findings suggest that inclusion of β-1,3 glucan-FOS in diets could enhance red tilapia biochemical parameters, growth, and protection against pathogenic V. alginolyticus infection. [ABSTRACT FROM AUTHOR]

The purpose of the present research was to evaluate the effect of diets supplemented with activated yeast, crude chitin, and chitosan on the growth, immune, and antioxidant response of freshwater prawn Cryphiops (Cryphiops) caementarius. Adult male prawns were kept in individual culture vessels installed in aquarium tanks. The basal diet (control) was supplemented with activated Saccharomyces cerevisiae yeast (60 g/kg), crude chitin (20 g/kg), and chitosan (1 g/kg). Each dietary treatment consisted of three replicates. The diet supplemented with activated yeast causes greater growth, as well as a greater number of total hemocytes (82.54 × 105 cells/mL), semigranular (59 × 105 cells/mL), and granular (18.67 × 105 cells/mL) hemocytes and without atypical hemocytes. Furthermore, a higher number of hemocytes positive for prophenoloxidase (98%), a shorter hemolymph clotting time (42.87 s), a higher activity of acid phosphatase (12.50 U/mL) and glutathione‐S‐transferase (GST) (0.186 U/mL) were also observed in dietary yeast group. On the contrary, there were no differences in the activity of superoxide dismutase (SOD) enzyme in prawns from any dietary treatment. Results from this research demonstrate for the first time that the diet containing activated yeast increases the growth and immune response of the freshwater prawn through a significant increase in hemocyte and acid phosphatase levels, a decrease in hemolymph clotting time, and a greater number of proPO‐positive hemocytes. However, activated yeast is not effective in increasing the activity of antioxidant enzymes SOD and GST. Therefore, the activated yeast diet can be useful to improve the aquaculture production of C. (C.) caementarius and possibly of other commercially important crustaceans. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to evaluate the efficiency of tea polyphenols (TP) and medicinal plant mixtures (Astragalus membranaceus + Lonicera japonica, Rheum officinale Bail + Scutellaria baicalensis + Platycladus orientalis) combined with astaxanthin (AST), benzoic acid (BA), and yeast complex on the health status of Eriocheir sinensis. Method: A total of 630 crabs (male crabs: 41.51 ± 1.63 g; female crabs: 47.27 ± 0.79 g) were randomly distributed into seven groups with three replicates (male: female, 1:1). These crabs were fed as follows for 8 weeks: basal diet (M1), M2 (M1 + 100 mg/kg TP), M3 (M1 + 2.0 g/kg A. membranaceus + 20 g/kg L. japonica), M4 (M1 + 2.5 g/kg R. officinale Bail + 1.5 g/kg S. baicalensis + 1.0 g/kg P. orientalis), and M5, M6, M7 (M2, M3 and M4 with 600 mg/kg AST +1.0 g/kg BA + 20 mg/kg yeast complex added, respectively). Results and discussion: The results showed that the activities of acid phosphatase (ACP), alkaline phosphatase (AKP), and lysosome (LZM) in the hemolymph were significantly increased in M5, M6, and M7 (P < 0.05), and the highest phagocytosis index (PI) and LZM activity were observed in M7 of female crabs. Moreover, the antioxidant indicators superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx), and catalase (CAT) of hepatopancreas were also significantly improved in M5, M6, and M7 (P < 0.05), while the malondialdehyde (MDA) contents showed an opposite trend. Furthermore, a morphological examination also showed the improved histological structure of hepatopancreas in M7, especially as seen in the clear lumens, no vacuolation, and integrity of the basal membrane of the hepatopancreatic tubule. Taken together, these results suggested that 2.5 g/kg R. officinale Bail, 1.5 g/kg S. baicalensis, and 1.0 g/kg P. orientalis in combination with 600 mg/kg AST, 1.0 g/kg BA, and 20 mg/kg yeast complex could improve the non-specific immunity, antioxidant capacity, and hepatopancreatic health of E. sinensis. [ABSTRACT FROM AUTHOR]

Protein deficiency is a major difficulty for human needs in the past few decades, while different types of aquatic species are rich in high quality protein. Therefore, aquaculture is considered as the main developing food production sector globally. Bacterial infections are the main problem for aquaculture, and their outbreaks have a great impact on productivity, and previously indiscriminate use of antibiotics to control them. However, the emergence of multidrug-resistant pathogens might lead to sudden infectious disease outbreaks resulting in serious economic loss. Immunostimulants application is an effective technique to protect and enhance the immune system of aquatic animals and therefore improve aquaculture production. Nutrient immunostimulants such as essential fatty acids, amino acids, vitamins, and minerals are the most important responsibility to improve aquaculture production, as well as the cost of this method, which is effective, non-toxic, and environment friendly. These nutrient immunostimulants are supportive to increase the immune system, antioxidant, antiinflammatory, and infection resistance of aquatic animals. In addition, nutritional feed additives improved feed palatability and the excellence of aquatic products and also enhance gut functions. Some information is available on nutrient immunostimulants in aquaculture applications, and this review provides information on different kinds of nutritional administration used in aquaculture to enhance positive impacts on aquatic animals' health as well as feed quality development. This review will provide theoretical references for the application of nutrient immunostimulants in aquatic feeds. [ABSTRACT FROM AUTHOR]

Litopenaeus vannamei, a highly adaptable shrimp species known for its growth, thrives in environmental conditions with proper water quality. However, salinity stress poses a significant challenge, compromising shrimp survival and growth. To optimize shrimp feed, the inclusion of alginate and Spirulina sp. offers benefits such as enhanced growth and resistance to environmental stress. This research aims to assess the impact of adding Spirulina sp., alginate, and their combination on the survival rate, resistance to the salinity shock test, and growth of L. vannamei. In this study, a completely randomized design (CRD) method with nine different feed doses was used. The treatments included control, supplementation of Alg 1 (alginate 1 g/kg feed), Alg 3 (alginate 3 g/kg feed), Alg 5 (alginate 5 g/kg feed), Sp 3 (spirulina 3 mg/kg feed), Sp 6 (spirulina 6 mg/kg feed), Sp 9 (spirulina 9 mg/kg feed), AS 1+1 (alginate 1 g/kg feed + spirulina 1 mg/kg feed), AS 2+3 (alginate 2 g/kg feed + spirulina 3 mg/kg feed), and AS 3+5 (alginate 3 g/kg feed + spirulina 5 mg/kg feed). The supplementation of feed was given during the fourteen-day rearing period. The results of the study show that the supplementation of Sp 9 (spirulina 9 mg/kg feed) led to a significant growth (α = 0.05). All treatments supplemented with alginate and/or Spirulina sp. water extract had a significant effect (α = 0.05) on the resistance to the salinity shock test. The different treatments in L. vannamei feed supplementation significantly influenced (α = 0.05) shrimp survival. Polysaccharides and antioxidant properties in alginate and Spirulina sp. have an important role in increasing the growth and resistance to salinity shock of L. vannamei.

Atlantic salmon (Salmo salar) were fed diets containing black soldier fly larvae (BSFL) meal at two inclusion levels for 13 months in open sea-cages. BSFL meal replaced plant-based ingredients and dietary insect meal inclusion levels were at 5% and 10%. A commercial salmon diet was fed as a control diet. Fish were reared from ~173 g to ~ 4 kg andwere randomly distributed into nine open sea-cages with ~6000 salmon/cage (12×12m²; 1900m³). Fish from the sea-cages were sampled at two time points (mid and final samplings) to study the dietary effects of BSFL meal on the general health and welfare. Monthly assessments of sea-lice and gill score were conducted to evaluate the overall well-being of the salmon. The findings from the current study revealed that dietary inclusion of BSFL meal up to 10% did not have any significant effects in general growth, welfare or survival. However, significant positive response was observed in the general skin mucosal, hematological, and gene expression profiles of salmon. Notably, the group of salmon fed with 5% BSFL meal showed a significant decrease in plasma aspartate transaminase and alanine transaminase. Also, a significantly higher expression of interleukin1β in both skin and gill along with upregulation of matrix metallopeptidase9 and mucin18 in gill were observed in salmonfedBSFL at 5%, which aidedinincreased immune responses. A part fromthat, this group had significantly higher mucus secretions, decreased cortisol response and increased number of erythrocytes. Furthermore, the delousing stress had a significant effect on the plasma cortisol, and these responses were independent of the dietary effect. Moreover, these immune responses behaved differently at different fish size and time points, acknowledging the influence of various factors in immune modulation. Overall, the findings from this study showed the effects of dietary BSFL meal to modulate the immune status of salmon. This study aims to fill the existing knowledge gaps regarding the impact of incorporating BSFL meal as a functional feed ingredient into the salmon diet on health and immune status replicating real farm conditions. [ABSTRACT FROM AUTHOR]

Herbal plants contain active bio-compounds that may stimulate the nonspecific immune system of animals and, as a result, play an important role as growth promoters and immunostimulants. To this end, the present study was set up to assess the efficacy of herbal extracts derived from two aromatic plants, ginger (Zingiber officinale) and clove (Syzygium aromaticum), as natural immunostimulants on the survival, growth performance, and immune response of farmed prawn Penaeus monodon juveniles. Seven experimental diets with an average of 40% CP were supplemented with herbal extracts at percentages of 0, 1, 2, and 3, then administered to prawns with an average size of 0.16 ± 0.12 g (at stocking) for 14 weeks, followed by a 2-week challenge test against Vibrio harveyi. Extract inclusion positively impacted weight gain, feed conversion ratio (FCR), and specific growth rate (SGR). Also, extract inclusion significantly improved the survival rate of the prawn after the challenge (p < 0.05). Significantly high total hemocyte counts (THC) were observed in the 2% Z. officinale and 3% S. aromaticum treated groups before the challenge. The study indicates that the groups exposed to the herbal extracts derived from ginger (Z. officinale) and clove (S. aromaticum) demonstrated significant resistance against bacterial infection (p < 0.05). Ginger and clove extracts have been observed to optimally boost P. monodon growth, survival, and immunity, at inclusion levels of 2 and 3%, respectively, hence hold promising potential as natural alternatives to antibiotics in managing Vibrio harveyi infections and promoting the growth, survival, and immunity of P. monodon in prawn farming systems. [ABSTRACT FROM AUTHOR]

The human immune system responds to harmful foreign invaders frequently encountered by the body and employs defense mechanisms to counteract such assaults. Various exogenous and endogenous factors play a prominent role in maintaining the balanced functioning of the immune system, which can result in immune suppression or immune stimulation. With the advent of different immune-modulatory agents, immune responses can be modulated or regulated to control infections and other health effects. Literature provides evidence on various immunomodulators from different sources and their role in modulating immune responses. Due to the limited efficacy of current drugs and the rise in drug resistance, there is a growing need for new therapies for infectious diseases. In this review, we aim to provide a comprehensive overview of different immune-modulating agents and immune therapies specifically focused on viral infectious diseases. [ABSTRACT FROM AUTHOR]

Common carp are proper finfish species for intensification, though their feeds should be reinforced with functional additives to ensure high growth performance and health status. Thus, this study tested the combined effects of butyl hydroxytoluene (BHT) and vitamin C (VC) on the growth performance, blood biomarkers, and antioxidative capacity of common carp. Fish were allotted into four groups and fed on four diets where the control diet was free of VC or/and BHT, while the second and third diets contained dietary VC or BHT at 500 or 150 mg/kg, respectively. The fourth diet was supplemented with both VC (500 mg/kg) and BHT (150 mg/kg) (BHT+VC). After 70 days, feeding VC or/and BHT markedly affected the growth performance of common carp. Carps fed VC, BHT, or BHT+VC had higher (P<0.05) FBW, WG, and SGR than fish fed the control diet, while the FCR was lower (P<0.05) in fish fed both VC and BHT than the control. In addition, feeding BHT or both BHT+VC markedly (P<0.05) reduced the AST, ALT, and urea. The blood protein, albumin, and globulin were higher (P<0.05) in fish fed VC or/and BHT than in the control. Fish fed dietary VC, or BHT+VC, had lower (P<0.05) total cholesterol (T-CHO) and triglycerides (TG) than those fed on the control or BHT. The SOD, CAT, and GPX were significantly higher (P<0.05) in carp fed on dietary VC or/and BHT than in fish fed on the control diet. Nevertheless, the malondialdehyde level was lower (P<0.05) in carp fed on VC or BHT+VC diets than fish on the control or BHT diets. The lysozyme activity was significantly higher (P<0.05) in carp fed on the BHT+VC diet than in the control or VC. In conclusion, the study suggests that dietary BHT or/and VC can be added to the diets of common carp to enhance the growth performance, feed digestion, blood biomarkers, and antioxidative capacity. [ABSTRACT FROM AUTHOR]

The objective of this study was to explore the effects of black seed (Nigella sativa) and AQUA-IMMUNOPROTECT® on growth, feed utilization, serum constituents, and disease resistance against vibriosis in gilthead sea bream juveniles. The research involved three groups: TC (control) received a basal diet, TSI (received a basal diet with 2% AQUA-IMMUNOPROTECT®), and TNS (received a basal diet with 2% N. sativa). The experiment period extended for 2 months. Results revealed a significant rise in erythrogram (RBCs, HB, and PCV %), leucogram (total differential leucocytic count), serum total protein, and globulin in gilthead sea bream treated with 2% Nigella sativa supplemented diets after an 8-week trial. No substantial variations were found in liver enzymes, urea, uric acid, and creatinine between the groups. Respiratory burst activity was notably greater in the N. sativa group after 2 months of feeding compared to the other groups. In the experimental challenge, the control group experienced higher mortality rates than the other groups following an IP injection of V. harveyi at a dose of 106 CFU per 0.5 ml/fish (106 fish/challenge). Overall, the findings of this research indicate that N. sativa can enhance non-specific immunity and minimize susceptibility and pathogenicity to V. harveyi in gilthead sea bream. [ABSTRACT FROM AUTHOR]

Herbs and their by-products are important traditional medicines and food supplements; they provide numerous beneficial effects for animals. Consequently, probiotics are living cell organisms, nontoxic, and friendly microbes. Probiotics have numerous beneficial activities such as inhibition of pathogens, enhancement of the immune system, growth, disease resistance, improving water quality, reducing toxic effects, synthesis of vitamins, prevention of cancer, reduction of irritable bowel syndrome, and more positive responses in animals. Herbal and probiotic combinations have more active responses and produce new substances to enhance beneficial responses in animals. Herbal and probiotic mixture report is still limited applications for animals. However, the mechanisms by which they interact with the immune system and gut microbiota in animals are largely unclear. This review provides some information on the effect of herbal and probiotic blend on animals. This review discusses current research advancements to fulfill research gaps and promote effective and healthy animal production. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of dietary supplementation with the essential oil of Minthostachys mollis on growth, fillet composition, hematological parameters, and disease resistance in juvenile Brycon amazonicus. A total of 120 fish (47.8 ± 7.7 g and 15.2 ± 0.7 cm) were randomly distributed in 12 tanks of 600 L (10 fish per tank) and fed commercial diets (28% protein and 5% lipids) supplemented with different levels of essential oil (0, 0.5, 1.0, and 1.5%), with three repetitions three times a day for 30 days. After 30 days, growth, hematological parameters, and fillet composition were evaluated. Disease resistance was tested by intraperitoneal injection of Aeromonas hydrophila (1.1 × 1012 CFU/mL) in five fish per tank, and mortality and hematological parameters were evaluated after 10 days. The results showed that the growth and hematological parameters of fish supplemented with 0.5 and 1.0% essential oil did not differ from the control group, but with 1.5% supplementation weight parameters, condition factor (1.27) and the mean corpuscular volume (188.9 fL) decreased, while glucose levels (114.8 mg dL−1) increased. In the fillet composition, there was only an effect on protein, which increased (19.8–19.9%) in fish fed the diets supplemented with essential oil. The bacterial infection did not affect survival, in hematological parameters, only glucose (87.4 mg dL−1) decreased in fish supplemented with 1.5% essential oil. It can be concluded that supplementation with the essential oil of M. mollis can increase the protein content in the fillets of B. amazonicus juveniles. [ABSTRACT FROM AUTHOR]

Simple Summary: In salmonid aquaculture, new prophylactic methods are needed to combat infectious diseases. Bacterial inclusion bodies are nanostructured particles of recombinant proteins formed during recombinant protein production processes. They are mainly composed of functional recombinant proteins, highly stable without the need for encapsulation, and can be produced through a cost-effective bacterial process. Different applications of these nanoparticles have been described, including their ability to enhance immune function. These characteristics make them very attractive for use in aquaculture. This study explored the production of three immune-related proteins as inclusion bodies and evaluated their ability to stimulate the immune response in the rainbow trout RTS11 cell line. In addition, we characterized the scaling-up of inclusion bodies production by comparing two different scale systems. We successfully produced three proteins as inclusion bodies that are able to activate the immune response in a cell line. Regarding the scaling-up of production, we observed that the inclusion bodies produced in a bioreactor were the smallest and had a greater ability to activate the immune response in the RTS11 cell line than in the same protein produced in a shaken flask. More studies are needed to characterize the immune response activated by these inclusion bodies and the optimal production conditions in bioreactors for generating inclusion bodies, such as media, fed-batch production, and mechanical bacterial lysis. Recent studies have demonstrated that immune-related recombinant proteins can enhance immune function, increasing host survival against infectious diseases in salmonids. This research evaluated inclusion bodies (IBs) of antimicrobial peptides (CAMPIB and HAMPIB) and a cytokine (IL1βIB and TNFαIB) as potential immunostimulants in farmed salmonids. For this purpose, we produced five IBs (including iRFPIB as a control), and we evaluated their ability to modulate immune marker gene expression of three IBs in the RTS11 cell line by RT–qPCR. Additionally, we characterized the scale-up of IBs production by comparing two different scale systems. The results showed that CAMPIB can increase the upregulation of tnfα, il1β, il8, and il10, HAMPIB significantly increases the upregulation of tnfα, inos, and il10, and IL1βIB significantly upregulated the expression of tnfα, il1β, and cox2. A comparison of IL1βIB production showed that the yield was greater in shake flasks than in bioreactors (39 ± 1.15 mg/L and 14.5 ± 4.08 mg/L), and larger nanoparticles were produced in shake flasks (540 ± 129 nm and 427 ± 134 nm, p < 0.0001, respectively). However, compared with its shake flask counterpart, the IL1βIB produced in a bioreactor has an increased immunomodulatory ability. Further studies are needed to understand the immune response pathways activated by IBs and the optimal production conditions in bioreactors, such as a defined medium, fed-batch production, and mechanical bacterial lysis, to increase yield. [ABSTRACT FROM AUTHOR]

Nowadays, the use of seaweed derivatives in aquaculture has drawn attention for their potential as an immunostimulant and growth promotor. The sulfated polysaccharide extracted (SPE) from green (Caulerpa sp.; SPC) and brown (Padina sp.; SPP) seaweeds with two concentrations (0.05% and 0.1%); nominated in four groups: SPC0.05, SPC0.1, SPP0.05, SPP0.1 and control group (free of SPE) were used for juvenile rainbow trout (Oncorhynchus mykiss) diet. Fish (N: 150; 8.5 ± 0.2 g) were selected aleatory distributed in 15 circular tanks (triplicate for the group) and fed test diets for 56 days. The outcomes revealed that the supplementation of SPE up to 1 g kg−1 failed to show significant differences in the organosomatic indices as compared to the control group. The most inferior protein value of dress‐out fish composition was observed in the fish fed the control diet, which was statistically lower than the SCP0.1 group (p < 0.05), while no significant difference was observed in other macronutrient composition among the treatments. Total monounsaturated fatty acid (MUFA) had lower trend in the carcass of fish fed SPE supplemented diets, so that lowest MUFA were observed in SPC0.05 group (p < 0.05; 25.22 ± 4.29%). The lowest value of docosahexaenoic acid was observed in the control diet compared to the SPE‐supplemented diets (p < 0.05). The serum alternative complement pathway levels in all treatments tend to promote compared to the control treatment. A similar trend was observed for lysozyme activity. According to the results, the superoxide dismutase (SOD) value were highest in SPC0.05 and SPC0.1 compared to the other treatments (p < 0.05), while a further elevation of the SPEPadina sp. extracted level (SPP0.1) leads to a decrease in SOD value. Thiobarbituric acid reactive substances of plasma was indicated not to influence by sulfated polysaccharide extracts in the refrigerated storage. The lowest serum stress indicators were observed in fish fed SPP0.05 group postchallenge test. Taken together, our outcomes revealed that SPE of two species of seaweeds bestows benefits in some of the immunity and antioxidant system. Also, notable elevations in HUFA were observed in juvenile rainbow trout fed supplemented with SPE. [ABSTRACT FROM AUTHOR]

Immunostimulants were widely used in aquafeed due to their multiple important functions, including promoting growth, enhancing non‐specific defence mechanisms and resisting infectious diseases. But the efficiencies of the positive effects of immunostimulants were affected by the duration of the administration and their dose. Short‐term and normal‐dose of immunostimulants promoted the growth and enhance non‐specific immunity of aquatic animals. However, improper use led to several immune disorders, including immune tolerance, immune exhaustion and over‐immunity. The application of two immunostimulant diets in rotation technique and the intermittent use of immune stimulant diets may solve the problems associated with immune disorders, but this application method will be limited by both species and immunostimulants. The occurrence of immune disorders is accompanied by different degrees of gut microbiota dysbiosis, especially significantly up‐regulated the abundance of Proteobacteria. Besides, the gut symbiotic microbiota plays a significant role in host immunity. Consequently, the regulation of gut microbiota may be an effective way to modulate immune disorders caused by improper use of polysaccharide immunostimulants. Regulating the gut microbiota not only solves the negative effects caused by improper use of immunostimulants without restrictions on both species and immunostimulants, but also has the advantage of simplicity and convenience compared to conventional approaches. In summary, this article reviews the possible negative effects caused by improper use of immunostimulants on aquatic animals and compares regular approaches with regulating gut microbiota. And gut microbiota maybe be used as a therapeutic target to improve immune disorders caused by immunostimulants in aquatic animals. [ABSTRACT FROM AUTHOR]

Abstract Mannan oligosaccharides (MOS) have shown to stimulate immune response in different fish species, but the results may appear contradictory and have not been tested in conjunction with vaccination. We hypothesized that dietary MOS supplementation could enhance efficacy and immune responses after immunization with a novel hydrogen peroxide‐inactivated vaccine. Nile Tilapia, Oreochromis niloticus, fingerlings were distributed into four groups (supplemented or not, vaccinated or not) and were used to determine immune and hematological parameters and somatic indexes. For the bacterial challenge and vaccine efficacy test, fish were assigned to five experimental groups. Twenty‐eight days after the feeding trial and vaccination, the groups were challenged intraperitoneally and monitored for 21 days. The relative percent survival of the groups basal diet‐vaccinated and MOS diet‐vaccinated were 98.1% and 100.0%, respectively. The dietary inclusion of MOS after vaccination for 28 days had no influence on vaccine efficacy, which could be explained because of the high efficacy of the vaccine itself. Therefore, we suggest that the contribution of MOS supplementation to immune responses after vaccination in fish would be greater for vaccines with lower efficacy, or when tested for heterologous challenges or for crossed protection.

This editorial, published in the journal Frontiers in Veterinary Science, discusses the use of natural immunomodulators in veterinary medicine. The article highlights the use of Chinese herbal medicines, probiotics, and plant polysaccharides as immunomodulators in various animals. The authors emphasize the need for further research in this area to deepen our understanding of the role of natural immunomodulators in veterinary medicine. The article provides valuable insights into the field of veterinary science and its impact on animal health. [Extracted from the article]

Abstract Among the potential feed additives, β-glucans are known to positively affect the growth performance, blood parameters, and intestinal microbiota of fish, even the ornamental species. Therefore, the present study evaluated the effects of the dietary supplementation of different Saccharomyces cerevisiae β-glucans concentrations (0, 0.05, 0.1, and 0.2%) in juvenile angelfish (Pterophyllum scalare) over a 42-day period. Regarding growth performance, no effects were observed on most parameters. However, 0.2% β-glucans supplementation produced higher condition factor values, indicating a better nutritional status. Furthermore, β-glucans supplementation did not affect blood parameters. Regarding intestinal microbiota, β-glucans supplementation increased the abundance of the potentially beneficial bacterial genus Phascolarctobacterium. The high abundance of bacteria from the phylum Bacteroidetes, which can degrade β-glucans, may be attributed to the increased abundance of Phascolarctobacterium spp. In addition, 0.2% β-glucans supplementation produced more operational taxonomic units and higher Sobs (observed species richness), indicating effects on the overall bacterial community structure. These results demonstrate the potential application of β-glucans as a dietary supplement to improve the performance and modulate the intestinal microbiota of angelfish.

Activating cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) holds great potential for cancer immunotherapy by eliciting type-I interferon (IFN-I) responses. Yet, current approaches to cGAS-STING activation rely on STING agonists, which suffer from difficult formulation, poor pharmacokinetics, and marginal clinical therapeutic efficacy. Here, we report nature-inspired oligonucleotide, Svg3, as a cGAS agonist for cGAS-STING activation in tumor combination immunotherapy. The hairpin-shaped Svg3 strongly binds to cGAS and enhances phase separation to form Svg3-cGAS liquid-like droplets. This results in cGAS-specific immunoactivation and robust IFN-I responses. Remarkably, Svg3 outperforms several state-of-the-art STING agonists in murine and human cells/tissues. Nanoparticle-delivered Svg3 reduces tumor immunosuppression and potentiates immune checkpoint blockade therapeutic efficacy of multiple syngeneic tumor models in wild-type mice, but in neither cGas−/− nor Sting−/− mice. Overall, these results demonstrate the great potential of Svg3 as a cGAS agonistic oligonucleotide for cancer combination immunotherapy.

One of the major bottlenecks affecting the expansion of the freshwater aquaculture sector in developing countries is the outbreak of diseases. Fish farmers have traditionally relied on antibiotics and synthetic chemicals to control diseases. However, antibiotics and synthetic chemicals are associated with negative effects on the environment and consumers and their excessive use has resulted in antibiotic-resistant pathogens. In addition, the majority of freshwater fish farmers, especially small-scale farmers, have limited access to antibiotics and synthetic chemicals due to lack of resources. Medicinal plants have been reported to be suitable replacements in aquaculture, but their usage in aquaculture is still limited. The aim of this paper is to undertake a meta-analysis on the effect of medicinal plants on innate immune response and disease resistance in commonly farmed freshwater aquaculture fish species, namely Mozambique tilapia (Oreochromis mossambicus), African catfish (Clarias gariepinus), trout (Oncorhynchus mykiss), and cyprinids (Labeo rohita and Cyprinus carpio). The analysis showed that the mean effect size for respiratory burst (− 1.90 (95% CI − 2.40; − 1.40), I2 = 100%, P = 0); lysozyme activity (0.05 (95% CI − 0.38; 0.48), I2 = 97%, P < 0.01); white blood cells (− 0.69 (95% CI − 1.16; − 0.23), I2 = 89%, P < 0.01); and phagocytic activity (− 1.21 (95% CI − 2.08; − 0.35), I2 = 91%, P < 0.01) was significantly different. Mean effect size for survival rates was not significantly different (2.56 (95% CI 0.10; 5.01), I2 = 0%, P = 1). The funnel plots for all parameters were asymmetrical, which indicates possible publication bias or the presence of systematic differences or inconsistencies among studies. Overall, the meta-analysis showed that medicinal plants could enhance immunity and disease resistance in tilapia, African catfish, carp, and trout. These findings reinforce the observation that plant supplements can be used to prevent disease outbreaks in aquaculture. It is therefore recommended that freshwater fish farmers in African regions such as Southern Africa learn to produce their own diets supplemented with plants at their farms in order to prevent diseases in cultured fish. [ABSTRACT FROM AUTHOR]

Mannan oligosaccharides (MOS) have shown to stimulate immune response in different fish species, but the results may appear contradictory and have not been tested in conjunction with vaccination. We hypothesized that dietary MOS supplementation could enhance efficacy and immune responses after immunization with a novel hydrogen peroxide‐inactivated vaccine. Nile Tilapia, Oreochromis niloticus, fingerlings were distributed into four groups (supplemented or not, vaccinated or not) and were used to determine immune and hematological parameters and somatic indexes. For the bacterial challenge and vaccine efficacy test, fish were assigned to five experimental groups. Twenty‐eight days after the feeding trial and vaccination, the groups were challenged intraperitoneally and monitored for 21 days. The relative percent survival of the groups basal diet‐vaccinated and MOS diet‐vaccinated were 98.1% and 100.0%, respectively. The dietary inclusion of MOS after vaccination for 28 days had no influence on vaccine efficacy, which could be explained because of the high efficacy of the vaccine itself. Therefore, we suggest that the contribution of MOS supplementation to immune responses after vaccination in fish would be greater for vaccines with lower efficacy, or when tested for heterologous challenges or for crossed protection. [ABSTRACT FROM AUTHOR]

The use of microorganisms isolated from the natural environment can improve the culture conditions in aquaculture systems and the immune and antioxidant response capacity of cultured organisms. In this study, the immunochemical response and gene expression of Litopenaeus vannamei juveniles were analyzed following exposure to microorganisms isolated from marine sediments after in vitro characterization of their probiotic properties. Two yeasts and one bacterium strain were used by immersion method (48 to 216 h) at a concentration of 1 × 106 CFU/mL with the following treatments: (1) Control, without probiotics; (2) Positive Control, commercial immunostimulant (Laminarin; β-1,3, glucan); (3) Candida maris, strain A1; (4) Geotrichum candidum, strain A3; and (5) Curtobacterium sp., strain S13. Shrimp treated with microorganisms and commercial immunostimulants showed a significant increase (P<0.0500) in the soluble protein content in hemocytes compared with the control group. At 72h post-exposure (hpe), G. candidum, Curtobacterium sp., and laminarin treatments showed a significant increase (P<0.0500) in superoxide desmutase (SOD) activity compared with the control group. SOD enzyme gene expression showed a significant increase (P<0.0500) in all shrimp treated with microorganisms from 48 hpe. The results obtained showed that the use of three microorganisms isolated from a marine environment can stimulate the protein content in circulating hemocytes, antioxidant activity, and gene expression in juvenile L. vannamei. [ABSTRACT FROM AUTHOR]

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Abstract Soybean meal (SBM) is widely used in shrimp feed agro‐industry as a fish meal (FM) replacement. However, high levels of SBM may compromise animal health as a result of nutrient imbalance. This study aimed to investigate the effects of feed enzyme combination (a mixture of 6‐phytase, serine protease, and endo‐1,3(4)‐β‐glucanase) and functional immunostimulant combination (a mixture of brewer's yeast, nucleotides, vitamin C, and vitamin E) in improving the overall health of Pacific white shrimp fed soybean‐based diet. Four diets were formulated with different amounts of SBM, FM, and poultry meal (PM): 0% SBM (with 25% FM and 12.6% PM), 30% SBM (with 12.5% FM and 5.7% PM), 30% SBM plus 0.045% feed enzymes, and 30% SBM plus 0.1% functional immunostimulants. The postlarvae were fed the test diets for 45 days. Then, the body weight, survival, FCR, Vibrio spp. count, and immune responses were analyzed. The resistance of shrimp to Vibrio parahaemolyticus infection was also evaluated. The results suggest that the diet with 30% SBM was deleterious to the shrimp's health. Feed enzymes and functional immunostimulant supplements improved overall performance, immune function, and resistance to V. parahaemolyticus infection of shrimp fed the diet containing 30% SBM compared with the 30% SBM diet without feed supplements.

Purpose. To analyze the productive-biological and biochemical parameters of sturgeon larvae and fry under conditions of introduction of synthetic (Levamisole) and organic (Chitosan) immunostimulants into their diet. To evaluate the effect of supplements on the stability of homeostatic processes based on the analysis of enzyme activity. Methodology. The study was carried out on juvenile hybrid besters (♀ Huso huso х ♂ Acipenser ruthenus) and sterlet (Acipenser ruthenus) (BSS). Larvae and fry were fed with Artemia nauplii, which were the transfer of immunostimulants after a six-hour enrichment in the respective solution. Pre-larvae, larvae and fry of sturgeon were reared in a RAS at the Lviv Research Station of the Institute of Fisheries of the National Academy of Sciences of Ukraine. During cultivation, the main productive parameters were studied, which included: weight, body length, growth rates, mortality, output from each stage of cultivation. The activity of α-amylase was determined by the Karavey’s method. Alanine aminotransferase activity was determined by the Reitman–Frenkel’s method. Alkaline phosphatase activity was determined by reaction with phenylphosphate. Gamma-glutamyltranspeptidase activity was determined by reaction with L-gamma-glutamyl-p-nitroaniline. All data were statistically processed using Statistica 6.0 and MS Excel. Findings. Addition of Levamisole to the diet during the first week of exogenous feeding had a positive effect on the growth processes of sturgeon larvae. The average weight of experimental fish in the experimental group No. 1 increased during the week by 3.96 times, which was 9% higher than the control values. In the experimental group No. 2, which consumed Chitosan, no significant difference was found compared to the average weight of the control group. Average daily growth was 24.9% in the experimental group No. 1 and 20.7% in the group No. 2, and 22% in the group No. 3, which served as a control. After 21 days of the experiment, the average body weight of juvenile sturgeons in the group No. 1, which consumed Levamisole, increased to 0.794 g, which exceeded the control values by 50.5%. The average weight of juveniles in the experimental group No. 2 was 0.661 g, which was 25.28% higher than the control group. The average growth rates were 9.3% in the group No. 1, 12.1% in the group No. 2, and 11.3% in the group No. 3. The short-term positive effect of immunostimulants on the activity of digestive enzymes of sturgeons in the juvenile period was shown. The activity of α-amylase in the body of fish for 21 days under the action of both Levamisole and Chitosan was higher than in the control by 88.2 and 91.4%, respectively. The analysis of the effect of immunostimulants on the activity of transferases (AlAT, LF, GGTP) of the tissues of internal organs confirmed the strengthening of the nonspecific resistance of the body in the short period of their action due to the activation of the transport processes of dephosphorylation and transamination. In addition, the activity of none of the enzymes indicated the impairment of homeostasis. Originality. The advisability of using synthetic and organic immunostimulants in raising sturgeons has been demonstrated. The effect of these supplements on the productive and biochemical parameters of juvenile sturgeons was evaluated. Practical value. The obtained results will be useful for improving the technology of early rearing of sturgeon larvae and fry. The application of the acquired knowledge will allow reducing mortality during critical periods of their cultivation and will allow strengthening the non-specific immunity of these valuable fish species.

The current study aimed at assessing the immunostimulatory properties of silver nanoparticles (AgNPs) on Labeo rohita, and understanding how it affects the growth, cellular ultrastructure, the expression level of immune genes, and infection risk from Aeromonas hydrophila. Fish (avg wt: 30.1±3.26 g) were fed diets with four separate AgNP inclusion levels (0 µgKg−1 [basic diet, T1], 10 µgKg−1 [T2], 15 µgKg−1 [T3], and 20 µgKg−1 [T4]) for 56 days. After the feeding trial, growth, histological, immunological parameters, and protective immune response against A. hydrophila were assessed. The fish in the treatment groups including T1(control), the T3 growth indices, such as specific growth rate (7.56±0.26) and percent weight gain (231.05±3.21), was statistically higher (P < 0.05). In the immunological and oxidative parameters, levels of SOD and catalase decreased in correlation with a rise in the inclusion doses of AgNP in the liver, and a reduction in catalase values was recorded in the gill. With the addition of AgNP, the NBT value was decreased in the gill, and T3 had a considerably larger (P

In the present study, goldfish (Carassius auratus) were fed diets supplemented with different levels of methanolic crude extracts of Andrographis paniculata to assess their efficacy against Aeromonas hydrophila. The A. paniculata extract showed antibacterial activity against A. hydrophila at different concentrations and was characterised by FTIR and GC-MS analysis. The fishes (C. auratus) were divided into three groups, the control fishes were fed with a basel diet, the DI and DII group fishes were fed with a basel diet mixed with 0.1% and 1% of methanolic crude extracts of A. paniculata, respectively for 4 weeks. Then, haematological and immunological parameters were examined in each experimental and control group after the 2nd and 4th week. Finally, all group fish were challenged with A. hydrophila at the end of the 4th week, and their cytokine genes expression were investigated. The results showed that even at low concentrations (50 μg) of A. paniculata leaf extracts showed a potent antibacterial effect against A. hydrophila. GC-MS analysis revealed that the methanol precipitation contains Benzylamine, 2-hydroxy-N,N-DI-[2-aminoethyl]-, 18-Nonadecen-1-OL, and andrographolide. Similarly, FTIR analysis revealed aliphatic primary amine, conjugated ketone and alcohols, which are known antimicrobials. The extracts also changed the growth, haematological and immunological parameters of treated fishes by significantly increased the total RBC counts and haemoglobin level, along with the phagocytic, total immunoglobulin and myeloperoxidase activities when compared to the BD group. Moreover, fish fed with 1% of A. paniculata extract showed a higher survival rate (80%) against A. hydrophila. Furthermore, 1% of A. paniculata extract dietary was significantly up-regulated pro-anti-inflammatory cytokine gene expression, compared with the BD group. In conclusion, dietary A. paniculata extract supplementation beneficial for C. auratus, as it assesses their efficacy against A. hydrophila.

Introduction: Immunomodulators are molecules of synthetic or biological origin that help to regulate the immune system. Many studies have focuses on exploring for phytochemical compounds that used as immunomodulatory properties in Indonesia, as well as in Sulawesi. The immunomodulatory activity of rhizome extract of E. flexuosa, an endemic flowering plant of Sulawesi on male mice were studied. Methods: 25 male mice (Mus musculus) used were randomly divided into 5 groups and Staphylococcus aureus (ATCC 25923) was used as inducer. The negative control group was given 0.5% Na-CMC (Carboxymethyl Cellulosa Sodium), positive control group was given stimuno® and treatment groups were an ethanol extract of E. flexuosa with successive doses of 200, 400 and 800 mg/kg body weight (BW) respectively. Each group was given the preparation orally for 7 days and on the 8th day the test animals were induced by Staphylococcus aureus bacteria intraperitoneally. The mice were dissected and the peritoneal fluid was taken to determine the activity of the macrophage cells. Meanwhile, Thomson and Weil method was used to study the acute toxicity test and determine the lethal dose 50 (LD50). Results: The percentage of macrophage activity in each group of negative control, positive control, extract doses of 200, 400 and 800 mg/kg BW respectively were 40.40%, 82.65%, 53.05%, 69.38% and 82.06%. Based on the results obtained, it was shown that the E. flexuosa rhizome extract has an optimum dose of 800 mg/kg BW, which was not significantly different from the positive control. Meanwhile, the symptoms of toxicity began to appear from a dose of 600 mg/kg BW to a dose of 2400 mg/kg BW including decreased motor activity, tremor, ataxia, lids and writhing. LD50 expressed in LD50 within the criteria of being practically nontoxic. Conclusions: The E. flexuosa rhizome ethanolic extract showed the immunomodulatory activity at optimum dose of 800 mg/kg BW by the increasing of macrophage phagocytosis activity. Moreover, the extract was also practically non-toxic based on LD50 value. [ABSTRACT FROM AUTHOR]

Atlantic salmon (Salmo salar) were fed diets containing black soldier fly larvae (BSFL) meal at two inclusion levels for 13 months in open sea-cages. BSFL meal replaced plant-based ingredients and dietary insect meal inclusion levels were at 5% and 10%. A commercial salmon diet was fed as a control diet. Fish were reared from ~173 g to ~ 4 kg andwere randomly distributed into nine open sea-cages with ~6000 salmon/cage (12×12m2; 1900m3). Fish from the sea-cages were sampled at two time points (mid and final samplings) to study the dietary effects of BSFL meal on the general health and welfare. Monthly assessments of sea-lice and gill score were conducted to evaluate the overall well-being of the salmon. The findings from the current study revealed that dietary inclusion of BSFL meal up to 10% did not have any significant effects in general growth, welfare or survival. However, significant positive response was observed in the general skin mucosal, hematological, and gene expression profiles of salmon. Notably, the group of salmon fed with 5% BSFL meal showed a significant decrease in plasma aspartate transaminase and alanine transaminase. Also, a significantly higher expression of interleukin1β in both skin and gill along with upregulation of matrix metallopeptidase9 and mucin18 in gill were observed in salmonfedBSFL at 5%, which aidedinincreased immune responses. A part fromthat, this group had significantly higher mucus secretions, decreased cortisol response and increased number of erythrocytes. Furthermore, the delousing stress had a significant effect on the plasma cortisol, and these responses were independent of the dietary effect. Moreover, these immune responses behaved differently at different fish size and time points, acknowledging the influence of various factors in immune modulation. Overall, the findings from this study showed the effects of dietary BSFL meal to modulate the immune status of salmon. This study aims to fill the existing knowledge gaps regarding the impact of incorporating BSFL meal as a functional feed ingredient into the salmon diet on health and immune status replicating real farm conditions. [ABSTRACT FROM AUTHOR]

Effectively treating and preventing outbreaks is crucial for improving the economic benefits of aquaculture. Therefore, utilizing immunostimulants, either alone or in combination, is regarded as a promising strategy. In this study, β-glucan + APS (200 mg/kg + 200 mg/kg), β-glucan (200 mg/kg), APS (200 mg/kg), enrofloxacin (15 mg/kg), and sulfadiazine (15 mg/kg) were added to feed to assess the effects against Nocardia seriolae infection in largemouth bass (Micropterus salmoides) within 14 days. The survival rates did not differ between the enrofloxacin group and the β-glucan + APS group, but both were significantly higher than that of the control group. Additionally, the enrofloxacin group and the β-glucan + APS group exhibited the lowest bacterial loads and tissue damage. Importantly, the β-glucan + APS treatment significantly improved serum enzyme activities (total superoxide dismutase, lysozyme, total protein) and the expression of immune genes (IL-1β, TNF-α, IFN-γ, IgM) compared to the other treatment groups. The enrofloxacin group showed similar efficacy to the β-glucan + APS group in combating N. seriolae infection, but N. seriolae in the enrofloxacin group developed drug resistance. In summary, the combined use of β-glucan and APS is a promising strategy for treating bacterial diseases, thereby contributing to the promotion of sustainable aquaculture development. [ABSTRACT FROM AUTHOR]

Tilapia species are among the most cultivated fish worldwide due to their biological advantages but face several challenges, including environmental impact and disease outbreaks. Feed additives, such as probiotics, prebiotics, and other microorganisms, have emerged as strategies to protect against pathogens and promote immune system activation and other host responses, with consequent reductions in antibiotic use. Because these additives also influence tilapia's gut microbiota and positively affect the tilapia culture, we assume it is a flexible annex organ capable of being subject to significant modifications without affecting the biological performance of the host. Therefore, we evaluated the effect of probiotics and other additives ingested by tilapia on its gut microbiota through a meta-analysis of several bioprojects studying the tilapia gut microbiota exposed to feed additives (probiotic, prebiotic, biofloc). A total of 221 tilapia gut microbiota samples from 14 bioprojects were evaluated. Alpha and beta diversity metrics showed no differentiation patterns in relation to the control group, either comparing additives as a group or individually. Results also revealed a control group with a wide dispersion pattern even when these fish did not receive additives. After concatenating the information, the tilapia gut core microbiota was represented by four enriched phyla including Proteobacteria (31%), Fusobacteria (23%), Actinobacteria (19%), and Firmicutes (16%), and seven minor phyla Planctomycetes (1%), Chlamydiae (1%), Chloroflexi (1%), Cyanobacteria (1%), Spirochaetes (1%), Deinococcus Thermus (1%), and Verrucomicrobia (1%). Finally, results suggest that the tilapia gut microbiota is a dynamic microbial community that can plastically respond to feed additives exposure with the potential to influence its taxonomic profile allowing a considerable optimal range of variation, probably guaranteeing its physiological function under different circumstances. [ABSTRACT FROM AUTHOR]

Increased intensive cultivation of Punten Carp (Cyprinus carpio L.) is quite profitable, but on the other hand, it can result in a decrease in water quality due to uncontrolled leftover feed. Poor water quality can cause fish to become stressed and then susceptible to disease, one of which is Myxobolus koi parasite infestation. The purpose of this study was to determine the effect of immunostimulant treatment of whole protein M. koi spores on the blood profile of Myxobolus-infested punten carp. The method used was an experiment with two treatments, the treatment without M. koi spore whole protein (P0) and the treatment of commercial feed added with an immunostimulant from M. koi spore whole protein of 5 µg/kg feed (P1). The study was conducted for 28 days and observed on days 0, 7, 14, 21, and 28, including the calculation of the number of erythrocytes, leukocytes, leukocyte differential, and water quality as supporting data. The abundance of erythrocytes in fish treated with P1 (1.16x106 cells/mm³ -2.44x106 cells/mm³ ) was higher than in fish treated with P0 (1.09x106 cells/mm³ -1.55x106 cells/mm³ ). The abundance of leukocytes in fish treated with P1 (3.79x104 cells/mm³ - 11.31x104 cells/ mm³ ) was higher than in fish treated with P0 (3.51x104 cells/ mm3 - 6.58x104 cells/mm3 ). The results of differential observations of leukocytes in the P0 treatment found basophils (0.3- 1.3%), neutrophils (12.3-21.5%), eosinophils (2.5-4.9%), lymphocytes (61.9-76.8%) and monocytes (3.8-6.3%). The results of differential observations of leukocytes in the P1 treatment found basophils (0.3-1.0%), neutrophils (10.7-19.9%), eosinophils (2.4-3.9%), lymphocytes (61.8-72.6%) and monocytes (3.9-5.4%). [ABSTRACT FROM AUTHOR]

Despite the creation of more and more new generations of antibacterial agents, the correction of intestinal dysbiosis in animals currently remains one of the most complex and urgent problems in clinical veterinary medicine. The article presents an analysis of the pathogenetic manifestation (microbial background, hematological analytes) in decompensated intestinal dysbacteriosis in domestic cats in the dynamics of its correction. The aim of the study was to study the comparative effectiveness of various pharmacotherapy regimens for decompensated intestinal dysbacteriosis in cats. The data shows that when correcting decompensated intestinal dysbacteriosis in domestic cats, the most rational treatment regimen is the complex use of Lactobifadol probiotic (contains at least 1.0 106 CFU/g of lactic acid bacteria Lactobacillus acidophilus LG1-DEP-VGIKI and 8.0 107 CFU/g of bifidobacteria Bifidobacterium adolescentis B-1-DEP-VGNKI), Vetelact prebiotic (contains lactulose - not less than 50 %), Azoksivet immunomodulator (contains 1.5 mg of azoximer bromide in 1 ml), as well as infusion therapy (intravenous drip injection of 10 ml/kg of 0.9 % sodium chloride solution; 10 ml/kg of 5 % glucose solution; 5 ml/kg of rheosorbelact and 2.5 ml/kg of refortan). This was confirmed by the results of pathogenetic picture (analysis of the microbial background and individual hematological analytes), in the dynamics of pharmacotherapy, namely before the start of correction, as well as on days 7 and 14. The improvement of diagnostic approaches and methods for correcting the most severe degree of intestinal dysbacteriosis (the stage of decompensation) creates prerequisites for the future study of dysbiotic disorders of the intestinal tract in other animal species, considering the severity of its manifestation.

Medicinally important plant-foods offer a balanced immune function, which is essential for protecting the body against antigenic invasion, mainly by microorganisms. Immunomodulators play pivotal roles in supporting immune function either suppressing or stimulating the immune system's response to invading pathogens. Among different immunomodulators, plant-based secondary metabolites have emerged as high potential not only for immune defense but also for cellular immunoresponsiveness. These natural immunomodulators can be developed into safer alternatives to the clinically used immunosuppressants and immunostimulant cytotoxic drugs which possess serious side effects. Many plants of different species have been reported to possess strong immunomodulating properties. The immunomodulatory effects of plant extracts and their bioactive metabolites have been suggested due to their diverse mechanisms of modulation of the complex immune system and their multifarious molecular targets. Phytochemicals such as alkaloids, flavonoids, terpenoids, carbohydrates and polyphenols have been reported as responsible for the immunomodulatory effects of several medicinal plants. This review illustrates the potent immunomodulatory effects of 65 plant secondary metabolites, including dietary compounds and their underlying mechanisms of action on cellular and humoral immune functions in in vitro and in vivo studies. The clinical potential of some of the compounds to be used for various immune-related disorders is highlighted. [ABSTRACT FROM AUTHOR]

Soybean meal (SBM) is widely used in shrimp feed agro‐industry as a fish meal (FM) replacement. However, high levels of SBM may compromise animal health as a result of nutrient imbalance. This study aimed to investigate the effects of feed enzyme combination (a mixture of 6‐phytase, serine protease, and endo‐1,3(4)‐β‐glucanase) and functional immunostimulant combination (a mixture of brewer's yeast, nucleotides, vitamin C, and vitamin E) in improving the overall health of Pacific white shrimp fed soybean‐based diet. Four diets were formulated with different amounts of SBM, FM, and poultry meal (PM): 0% SBM (with 25% FM and 12.6% PM), 30% SBM (with 12.5% FM and 5.7% PM), 30% SBM plus 0.045% feed enzymes, and 30% SBM plus 0.1% functional immunostimulants. The postlarvae were fed the test diets for 45 days. Then, the body weight, survival, FCR, Vibrio spp. count, and immune responses were analyzed. The resistance of shrimp to Vibrio parahaemolyticus infection was also evaluated. The results suggest that the diet with 30% SBM was deleterious to the shrimp's health. Feed enzymes and functional immunostimulant supplements improved overall performance, immune function, and resistance to V. parahaemolyticus infection of shrimp fed the diet containing 30% SBM compared with the 30% SBM diet without feed supplements. [ABSTRACT FROM AUTHOR]

Atlantic salmon (Salmo salar) were fed diets containing black soldier fly larvae (BSFL) meal at two inclusion levels for 13 months in open sea-cages. BSFL meal replaced plant-based ingredients and dietary insect meal inclusion levels were at 5% and 10%. A commercial salmon diet was fed as a control diet. Fish were reared from ~173 g to ~ 4 kg and were randomly distributed into nine open sea-cages with ~6000 salmon/cage (12×12 m2; 1900 m3). Fish from the sea-cages were sampled at two time points (mid and final samplings) to study the dietary effects of BSFL meal on the general health and welfare. Monthly assessments of sea-lice and gill score were conducted to evaluate the overall well-being of the salmon. The findings from the current study revealed that dietary inclusion of BSFL meal up to 10% did not have any significant effects in general growth, welfare or survival. However, significant positive response was observed in the general skin mucosal, hematological, and gene expression profiles of salmon. Notably, the group of salmon fed with 5% BSFL meal showed a significant decrease in plasma aspartate transaminase and alanine transaminase. Also, a significantly higher expression of interleukin1β in both skin and gill along with upregulation of matrix metallopeptidase9 and mucin18 in gill were observed in salmon fed BSFL at 5%, which aided in increased immune responses. Apart from that, this group had significantly higher mucus secretions, decreased cortisol response and increased number of erythrocytes. Furthermore, the delousing stress had a significant effect on the plasma cortisol, and these responses were independent of the dietary effect. Moreover, these immune responses behaved differently at different fish size and time points, acknowledging the influence of various factors in immune modulation. Overall, the findings from this study showed the effects of dietary BSFL meal to modulate the immune status of salmon. This study aims to fill the existing knowledge gaps regarding the impact of incorporating BSFL meal as a functional feed ingredient into the salmon diet on health and immune status replicating real farm conditions.