Growth, Hepatic Enzymatic Activity, and Quality of European Seabass Fed on Hermetia illucens and Poultry By-Product Meal in a Commercial Farm.

Protein meals from insects in combination with poultry by-product meal appear to be promising ingredients for replacing conventional proteins in the diets of carnivorous fish. The present study explored the effects on growth performance, hepatic enzymatic activity, and fillet physical and nutritional characteristics during a 66-day feeding trial performed on European seabass. A total of 3000 fish were distributed into three tanks, where the control group was fed with a commercial diet (CG) and a second group was fed in duplicate with the experimental diet (SSH) containing 10% Hermetia illucens larva meal, 30% poultry by-product meal, and <5.5 g/100 g of feed of marine origin proteins. All fish showed good growth performance. Glucose-6-phosphate dehydrogenase, aspartate aminotransferase, and 3-hydroxyacyl-CoA dehydrogenase activities were higher in the SSH group than in the CG group. The fillet fatty acid profile was largely unaffected by diet, except for a few fatty acids. Fish fed the SSH diet had a lower C22:1n-11 content than CG, thus suggesting an increased ß-oxidation. The oxidative status of muscle lipids was not affected by the diet. In conclusion, the present study showed that European seabass can be successfully fed the SSH diet for two months in a commercial setting.

The Effects of Short-Chain Fatty Acids in Gut Immune and Oxidative Responses of European Sea Bass (Dicentrarchus labrax): An Ex Vivo Approach.

This study aimed to evaluate the intestinal interactions between three short-chain fatty acids (SCFA), namely, acetate, propionate, and butyrate, and pathogenic bacteria (Vibrio anguillarum) in intestinal explants of European sea bass (Dicentrarchus labrax) juveniles. The anterior intestine of 12 fish with an average weight of 100 g (killed by excess anesthesia with 2-phenoxyethanol) were sampled and placed in 24-well plates. The experimental treatments consisted of a control medium and a control plus 1 mM or 10 mM of sodium acetate (SA), sodium butyrate (SB), and sodium propionate (SP). After 2 h of incubation, the explants were challenged with Vibrio anguillarum at 1 × 107 CFU/mL for 2 h. After the bacterial challenge, and regardless of the SCFA treatment, the oxidative stress-related genus catalase (cat) and superoxide dismutase (sod) were down-regulated and glutathione peroxidase (gpx) was up-regulated. Furthermore, the immune-related genes, i.e., the tumor necrosis factor (TNF-α), interleukin 8 (IL-8), transforming growth factor (TGF-ß), and nuclear factor (NF-Kß) were also up-regulated, and interleukin 10 (IL-10) was down-regulated. During the pre-challenge, sodium propionate and sodium butyrate seemed to bind the G-protein coupled receptor (grp40L), increasing its expression. During the challenge, citrate synthase (cs) was down-regulated, indicating that the SCFAs were used as an energy source to increase the immune and oxidative responses. Overall, our results suggest that sodium propionate and sodium butyrate may boost European sea bass immune response at the intestine level.

Black soldier fly larvae meal as a potential modulator of immune, inflammatory, and antioxidant status in gilthead seabream juveniles.

This study aimed to evaluate the effects of fish meal (FM) replacement with defatted Hermetia illucens larvae meal (HM) on the hematological profile, immune parameters, intestinal inflammatory status, and antioxidant response in gilthead seabream juveniles. Four diets were formulated, replacing FM with HM at 0%, 22%, 60%, and 100% levels, corresponding to an inclusion level of 15 (diet HM15), 30 (diet HM30), and 45% (diet HM45), respectively. Over 67 days, fish were fed these diets until apparent visual satiation. Results showed no significant differences in immune parameters or hematological profiles, except for a decrease in hemoglobin and hematocrit levels. In the liver, glucose-6-phosphate dehydrogenase and glutathione peroxidase decreased linearly with HM content, especially at 100% replacement. Glutathione reductase activity was also reduced with HM inclusion, being lower in fish fed diet HM30 compared to the control. Fish fed diet HM15 showed lower hepatic superoxide dismutase activity, while catalase activity and lipid peroxidation remained unaffected. In the intestine, antioxidant enzyme activity was not influenced by HM, but lipid peroxidation linearly decreased with HM inclusion, being lower in the HM30 diet compared to the control. The inclusion of HM reduced the expression of intestinal pro-inflammatory genes (interleukin-1ß and cyclooxygenase-2) while the expression of transforming growth factor ß was higher in fish fed diet HM30 compared to the control and HM45 diets. In conclusion, up to 45% dietary inclusion of HM showed no adverse effects, improving liver antioxidant status, reducing intestinal oxidative stress, and regulating inflammatory gene expression.

Oleic acid as modulator of oxidative stress in European sea bass (Dicentrarchus labrax) juveniles fed high dietary lipid levels.

Although the benefits of oleic acid (OA) have been established in mammals, its effects on fish remain understudied. The aim of this study was to evaluate the antioxidant potential of OA in the liver, intestine, and muscle of European sea bass juveniles fed diets containing different lipid levels. For that purpose, six diets with 16 or 22% lipids and 0, 1, and 2% OA were formulated and triplicate groups of European sea bass juveniles (21.4 g) were fed with these experimental diets for 9 weeks. Increasing dietary lipid levels or OA supplementation did not affect antioxidant enzyme activity in the liver and muscle. Superoxide dismutase (SOD) activity in the intestine increased with both the dietary lipid and OA levels, while glucose 6 phosphate dehydrogenase (G6PDH) activity increased only with dietary OA supplementation. Reduced glutathione (GSH) and total glutathione (tGSH) content were higher in the liver and intestine of fish fed the low-lipid diets, while in the high-lipid diets it was lower in the muscle than in the liver and intestine. Present findings suggest that OA plays a role in the antioxidant defense mechanisms of European sea bass, particularly at the intestine level, but additional research is required to further assess the potential benefits of incorporating OA into the diets.

Dietary ARA, DHA, and Carbohydrate Ratios Affect the Immune Status of Gilthead Sea Bream Juveniles upon Bacterial Challenge.

This study aims to assess the effects of different dietary n-6/n-3 long-chain polyunsaturated fatty acid ratios and CHO content in the immune response of gilthead seabream. For that purpose, gilthead sea bream juveniles (initial body weight = 47.5 g) were fed for 84 days with four isoproteic (47% crude protein) and isolipidic (18% crude lipids) diets with high (20%) or low (5%) level of gelatinized starch (HS or LS diets, respectively) and included approximately 2.4% ARA or DHA. At the end of the trial, the DHA-enriched groups presented increased red blood cell (RBC) count, hemoglobin, plasmatic nitric oxide (NO) content, and antiprotease and alternative complement activities. The ARA groups had increased thrombocyte count, and plasmatic bactericidal activity against Vibrio anguillarum was lower in the fish fed the ARA/LS diet. After the feeding trial, the fish were challenged with an intraperitoneal injection (i.p.) of killed Photobacterium damselae subsp. piscicida (Phdp) and sampled at 4 and 24 h after the challenge. At 4 h after i.p., the ARA groups presented increased plasma total immunoglobulins (Ig) and bactericidal activity against V. anguillarum. In addition, the fish fed the ARA/LS diet presented lower white blood cell (WBC) and alternative complement activity. At 24 h after i.p., the ARA groups presented increased RBC, WBC, and thrombocyte numbers, total IG, plasma peroxidase activity, and casp3 expression in the distal intestine. The HS groups presented increased plasma NO content and bactericidal activity against Phdp and decreased protease, antiprotease activity, and bactericidal activity against V. anguillarum. In conclusion, high dietary DHA levels seemed to improve the immune status of unchallenged gilthead sea bream juveniles, while high dietary ARA levels improved the fish immune response to a bacterial challenge. The energy provided by dietary starch seems to be important to promote a fast response by the fish immune system after a challenge.

Solid-State Fermentation as Green Technology to Improve the Use of Plant Feedstuffs as Ingredients in Diets for European Sea Bass (Dicentrarchus labrax) Juveniles.

This study aimed to evaluate the utilization by juvenile European sea bass of a SSFed PF mixture with Aspergillus niger CECT 2088. A 22-day digestibility and a 50-day growth trial were performed testing four diets, including 20 or 40% of an unfermented or SSFed PF mixture (rapeseed, soybean, rice bran, and sunflower seed meals, 25% each). SSF of the PF added cellulase and ß-glucosidase activity to the diets. Mycotoxin contamination was not detected in any of the experimental diets except for residual levels of zearalenone and deoxynivalenol (100 and 600 times lower than that established by the European Commission Recommendation-2006/576/EC). In diets including 20% PF, SSF did not affect growth but increased apparent digestibility coefficients of protein and energy, feed efficiency, and protein efficiency ratio. On the contrary, in diets including 40% PF, SSF decreased growth performance, feed intake, feed and protein efficiency, and diet digestibility. SSF decreased the intestinal amylase activity in the 40% SSFed diet, while total alkaline proteases decreased in the 20% and 40% SSFed diets. Hepatic amino acid catabolic enzyme activity was not modulated by SSF, and plasma total protein, cholesterol, and triglyceride levels were similar among dietary treatments. In conclusion, dietary inclusion of moderate levels of the SSFed PF, up to 20%, improves the overall feed utilization efficiency without negatively impacting European sea bass growth performance. The replacement of PF with the SSFed PF mixture may contribute to reducing the environmental footprint of aquaculture production.

Enrichment of a Plant Feedstuff Mixture's Nutritional Value through Solid-State Fermentation.

Plant feedstuffs are the main ingredients of animal feed. Owing to food-feed competition, increasing the utilization efficiency of these feedstuffs is important for animal nutrition. This can be achieved via solid-state fermentation (SSF). SSF of a plant feedstuff mixture (PFM) (25% rapeseed meal, soybean meal, rice bran, and sunflower meal) by three fungi (Aspergillus ibericus MUM 03.29, Aspergillus niger CECT 2088, and Aspergillus niger CECT 2915) resulted in an increase in protein content by 5%, irrespective of fungi, a reduction in cellulose content by 9 to 11%, and of hemicellulose content by 21 to 34%, relative to unfermented PFM. Enzyme production was measured: the highest cellulase (123.7 U/g), xylanase (431.8 U/g), and beta-glucosidase (117.9 U/g) activity were achieved with A. niger CECT 2088. Principal component analysis showed a positive correlation between all fermented PFMs and enzyme production, protein content, digestibility, and fiber reduction. Bioprocessing of the PFM by SSF increased its nutritional value and digestibility, making it more appealing for animal feeds.

Feeding Yellow Worms to Meagre: Effects on Whole-Body Fatty Acid Profile and Hepatic and Intestine Oxidative Status.

This study aimed to determine the effects of dietary inclusion of Tenebrio molitor larvae (yellow worms) meal (TM) on meagre fish (Argyrosomus regius) whole-body fatty acids (FA) profile and hepatic and intestine oxidative status. For that purpose, fish were fed for 9 weeks a fishmeal-based diet (control) or diets including 10%, 20%, or 30% TM. With the increase in dietary TM level, whole-body oleic acid, linoleic acid, monounsaturated FA, and n-6 polyunsaturated FA (PUFA) increased while saturated FA (SFA), n-3 PUFA, n-3 long chain-PUFA, SFA:PUFA ratio, n3:n6 ratio, and FA retention decreased. Hepatic superoxide dismutase (SOD), glucose-6-phosphate dehydrogenase (G6PDH), and glutathione reductase (GR) activities increased and catalase (CAT) and glutathione peroxidase (GPX) activities decreased with dietary TM inclusion. Hepatic total and reduced glutathione were lower in fish fed 20% TM. Intestinal CAT activity and oxidized glutathione increased and GPX activity decreased with dietary TM inclusion. Intestine SOD, G6PDH, and GR activities increased and malondialdehyde concentration decreased in fish fed the diets with lower TM inclusion levels. Liver and intestine oxidative stress index and liver malondialdehyde concentration were unaffected by dietary TM. In conclusion, to avoid major whole-body FA changes or antioxidant status imbalances, it is recommended to limit TM to 10% inclusion in meagre diets.

Hepatic, Muscle and Intestinal Oxidative Status and Plasmatic Parameters of Greater Amberjack (Seriola dumerili, Risso, 1810) Fed Diets with Fish Oil Replacement and Probiotic Addition.

The present study was conducted to investigate the effects of dietary fish oil replacement with a mixture of vegetable oils and probiotic supplementation on plasma biochemical parameters, oxidative stress, and antioxidant ability of Seriola dumerili. Specimens with an initial weight of 175 g were used. Four feeds were formulated with 0% (FO-100), 75% (FO-25), and 100% (FO-0 and FO-0+ with the addition of Lactobacillus probiotics) substitution of fish oil with a mixture of linseed, sunflower, and palm oils. After 109 days, no significant differences were observed in the activity of antioxidant enzymes in the liver, foregut, and hindgut, only glucose-6-phosphate dehydrogenase activity in the liver was higher in the fish fed the FO-100 diet than in those fed the FO-0 diet. No significant differences were observed in the total, reduced, and oxidized glutathione and the oxidative stress index in the liver. In addition, lipid peroxidation in the liver and red muscle values were higher in the fish fed the FO-100 diet than in the fish fed the FO-0+ diet, however, the foregut of the fish fed the FO-100 diet presented lower values than that of the fish fed the FO replacement diet, with and without probiotics. There were significant differences in cholesterol levels in the FO-100 group; they were significantly higher than those observed with the fish diets without fish oil. To sum up, fish oil can be replaced by up to 25% with vegetable oils in diets for Seriola dumerili juveniles, but total fish oil substitution is not feasible because it causes poor survival. The inclusion of probiotics in the FO-0+ diet had no effects on the parameters measured.

Solid-State Fermentation of Plant Feedstuff Mixture Affected the Physiological Responses of European Seabass (Dicentrarchus labrax) Reared at Different Temperatures and Subjected to Salinity Oscillation.

This study aimed to evaluate the effects of dietary inclusion of plant feedstuff mixture (PFM) pre-treated by solid-state fermentation (SSF) on the physiological responses of European seabass. For that purpose, two diets were formulated to contain: 20% inclusion level of non-fermented plant ingredients mixture (20Mix) and 20Mix fermented by A. niger in SSF conditions (20Mix-SSF). Seabass juveniles (initial body weight: 20.9 ± 3.3 g) were fed the experimental diets, reared at two different temperatures (21 and 26 °C) and subjected to weekly salinity oscillations for six weeks. Growth performance, digestive enzyme activities, humoral immune parameters, and oxidative stress indicators were evaluated. A reduction in weight gain, feed intake, and thermal growth coefficient was observed in fish fed the fermented diet (20Mix-SSF). Salinity oscillation led to an increase in weight gain, feed efficiency, daily growth index, and thermal growth coefficient, regardless of dietary treatment. Higher rearing temperatures also increased daily growth index. No dietary effect was observed on digestive enzymes activities, whereas rearing temperature and salinity oscillation modulated digestive enzyme activities. Oxidative stress responses were significantly affected by experimental diets, temperature, and salinity conditions. Catalase and glutathione peroxidase activities showed an interactive effect. Fish reared at 21 °C showed higher enzymatic activity when fed the 20Mix-SSF. Conversely, fish reared at 26 °C showed higher GPx activity when fed the 20Mix diet. Fish reared at 26 °C showed reduced peroxidase and lysozyme activities, while salinity fluctuation led to increased lysozyme activity and decreased ACH50 activity. ACH50 activity increased in fish fed the 20Mix-SSF. Overall, the dietary inclusion of PFM fermented by A. niger was unable to mitigate the impact of environmental stress on physiological performance in European seabass. In fact, fermented feed caused an inhibition of growth performances and an alteration of some physiological stress indicators.

Fatty acid-sensing mechanisms in the hypothalamus of European sea bass (Dicentrarchus labrax): The potential role of monounsaturated and polyunsaturated fatty acids.

This study aimed to evaluate the hypothalamus fatty acid (FA)-sensing mechanisms response to different FA in European sea bass. For that purpose, fish (body weight of 90 g) were intraperitoneally (IP) injected (time 0 h) with five long-chain unsaturated fatty acids, namely, docosahexaenoic acid (DHA; C22:5n3); eicosapentaenoic acid (EPA; C20:4n3); α-linolenic (ALA; C18:3n3); linoleic acid (LA; C18:2n6) and oleic acid (OA; C18:1n9) at a dose of 300 µg kg-1, or with 0.9% saline solution (control). Feed intake (FI) was recorded at 3, 6, and 24 h after the IP injection. One week later, fish were IP injected with the same FA, and the hypothalamus was collected 3 h after the IP injection for measurement of molecules related to FI regulation and FA-sensing mechanisms. Cumulative FI (g/kg/day) was not affected by treatments. However, compared to the control, FI increased with the OA treatment at 6 h after the IP injection. FI decreased with mealtime in the DHA and LA groups. Gene expression of orexigenic (npy/agrp) and anorexigenic (cart2/pomc1) neurons was not affected by the FA treatments. Attending the enzymes involved in the FA-sensing mechanisms activation, compared to the control carnitine palmitoyltransferase I (CPT1) and ATP citrate lyase (ACLY) activity were not affected by FA treatments. Contrarily the key enzymes of lipid metabolisms, malic enzyme and hydroxyacylCoA dehydrogenase was higher in fish that received the EPA and OA treatment, than fish treated to the control. Overall, the results of the present study indicate that gene expression of orexigenic and anorexigenic neurons was not affected at 3 h after IP injection with different FA. However, the activity of key enzymes of lipid metabolism was differently affected by circulating FA, indicating that FA-sensing mechanisms respond to different FA. Further studies are required involving different sampling times to further characterize the response of FA-sensing mechanisms to FA. These findings may be of relevance to the aquaculture industry in an era where alternative lipid sources are being increasingly used.

Shelf-Life Performance of Fish Feed Supplemented with Bioactive Extracts from Fermented Olive Mill and Winery By-Products.

Fortifying fish feeds with bioactive compounds, such as enzymes and antioxidants, has been an adopted strategy to improve feed nutritional quality and sustainability. However, feed additives can lose activity/effectiveness during pelleting and storage processes. This work aimed to monitor functional activity stability in feeds supplemented with a bioactive extract, including cellulases, xylanases, and antioxidants. This bioactive extract (FBE) was produced by Aspergillus ibericus under solid-state fermentation of olive mill and winery by-products. Two isoproteic and isolipidic diets were formulated and unsupplemented or supplemented with lyophilized FBE (0.26% w/w). Both diets were stored at room temperature (RT) or 4 °C for 4 months. Results showed that feed storage at 4 °C enhanced the stability of the enzymes and cellulase was more stable than xylanase. Compared to RT, storage at 4 °C increased cellulase and xylanase half-life by circa 60 and 14%. Dietary FBE supplementation increased antioxidant activity and storage at 4 °C reduced antioxidant activity loss, while in the unsupplemented diet, antioxidant activity decreased to the same level in both storage temperatures. Dietary supplementation with FBE reduced lipid peroxidation by 17 and 19.5% when stored at 4 °C or RT, respectively. The present study is a step toward improving the storage conditions of diets formulated with bioactive compounds.

Potential of Red, Green and Brown Seaweeds as Substrates for Solid State Fermentation to Increase Their Nutritional Value and to Produce Enzymes.

Seaweeds are valuable feedstocks with the potential to be used as ingredients in aquafeeds. However, their use are still limited, given their recalcitrant polysaccharide structure. To break this structure, a biotechnological approach such as solid-state fermentation (SSF) by filamentous fungi can be used, which simultaneously increases the nutritional value of the biomass. However, SSF has hardly been studied in seaweeds; thus, in this study, five different seaweeds (Gracilaria sp., Porphyra dioica, Codium tomentosum, Ulva rigida, and Alaria esculenta) were used as substrates in SSF with Aspergillus ibericus MUM 03.49 and A. niger CECT 2915. Firstly, the seaweeds were fully characterized, and, then, changes in the crude protein and carbohydrate contents were assessed in the fermented biomass, as well as any carbohydrases production. The SSF of U. rigida with both fungi resulted in the maximum xylanase and ß-glucosidase activities. The maximum cellulase activity was achieved using Gracilaria sp. and U. rigida in the SSF with A. niger. The protein content increased in C. tomentosum after SSF with A. ibericus and in U. rigida after SSF with both fungi. Moreover, U. rigida's carbohydrate content decreased by 54% and 62% after SSF with A. ibericus and A. niger, respectively. Seaweed bioprocessing using SSF is a sustainable and cost-effective strategy that simultaneously produces high-value enzymes and nutritionally enhanced seaweeds to be included in aquafeeds.

Oxidative Stress Response of Meagre to Dietary Black Soldier Fly Meal.

This study aimed to assess the effect of Hermetia illucens meal (HM) dietary inclusion on meagre oxidative status. Thus, fish were fed a fishmeal-based diet (CTR diet) and three other diets with increasing levels of HM inclusion, namely 10%, 20%, and 30% (diets HM10, HM20, and HM30, respectively). At the end of the trial, hepatic and intestine superoxide dismutase, catalase, and glucose-6-phosphate dehydrogenase activities and malondialdehyde concentration were unaffected by the diet composition. Liver glutathione peroxidase activity was higher in the fish fed the HM20 diet than in the fish fed the CTR and HM30 diets, and glutathione reductase activity linearly increased with the dietary HM level. The hepatic total glutathione and reduced glutathione contents were significantly lower in fish fed the HM20 diet than in fish fed the CTR and HM10 diets. In the intestine, the oxidized glutathione (GSSG) content and oxidative stress index linearly increased with the increase in dietary HM level, with the GSSG content of fish fed the HM20 diet being significantly higher than of fish fed the CTR diet. In conclusion, 30% HM might be included in meagre diets without negatively affecting hepatic and intestine oxidative status.

The Interplay between Central and Peripheral Systems in Feed Intake Regulation in European Seabass (Dicentrarchus labrax) Juveniles.

The present study aimed to evaluate the effects of feeding or feed deprivation on the orexigenic and anorexigenic responses at the central (whole brain) and peripheral (anterior and posterior intestine, stomach, and liver) system levels in European seabass. For this purpose, a group of fish (208 g) was fed a single meal daily for 8 days (fed group) and another group was feed-deprived for 8 days (unfed group). Compared to the fed group, in the whole brain, feed deprivation did not induce changes in npy, agrp1, and cart2 expression, but increased agrp2 and pomc1 expression. In the anterior intestine, feed deprivation increased cck expression, while in the posterior intestine, the npy expression increased and pyyb decreased. In the stomach, the ghr expression decreased regardless of the feeding status. The hepatic lep expression increased in the unfed fish. The present results suggest a feed intake regulation mechanism in European seabass similar to that observed in other teleosts.

Valorization of Brewer's Spent Grain Using Biological Treatments and its Application in Feeds for European Seabass (Dicentrarchus labrax).

Brewer's spent grain (BSG) is the main brewery industry by-product, with potential applications in the feed and food industries due to its carbohydrate composition. In addition, the lignocellulosic nature of BSG makes it an adequate substrate for carbohydrases production. In this work, solid-state fermentation (SSF) of BSG was performed with Aspergillus ibericus, a non-mycotoxin producer fungus with a high capacity to hydrolyze the lignocellulosic matrix of the agro-industrial by-products. SSF was performed at different scales to produce a crude extract rich in cellulase and xylanase. The potential of the crude extract was tested in two different applications: -(1) - the enzymatic hydrolysis of the fermented BSG and (2) - as a supplement in aquafeeds. SSF of BSG increased the protein content from 25% to 29% (w/w), while the fiber content was reduced to 43%, and cellulose and hemicellulose contents were markedly reduced to around 15%. The scale-up of SSF from 10 g of dry BSG in flasks to 50 g or 400 g in tray-type bioreactors increased 55% and 25% production of cellulase and xylanase, up to 323 and 1073 U g-1 BSG, respectively. The optimum temperature and pH of maximal activities were found to be 55°C and pH 4.4 for xylanase and 50°C and pH 3.9 for cellulase, cellulase being more thermostable than xylanase when exposed at temperatures from 45°C to 60°C. A Box-Behnken factorial design was applied to optimize the hydrolysis of the fermented BSG by crude extract. The crude extract load was a significant factor in sugars release, highlighting the role of hydrolytic enzymes, while the load of fermented BSG, and addition of a commercial ß-glucosidase were responsible for the highest phenolic compounds and antioxidant activity release. The lyophilized crude extract (12,400 and 1050 U g-1 lyophilized extract of xylanase and cellulase, respectively) was also tested as an enzyme supplement in aquafeed for European seabass (Dicentrarchus labrax) juveniles. The dietary supplementation with the crude extract significantly improved feed and protein utilization. The processing of BSG using biological treatments, such as SSF with A. ibericus, led to the production of a nutritionally enriched BSG and a crude extract with highly efficient carbohydrases capable of hydrolyzing lignocellulosic substrates, such as BSG, and with the potential to be used as feed enzymes with remarkable results in improving feed utilization of an important aquaculture fish species.

In vitro modulation of gilthead seabream (Sparus aurata L.) leukocytes by Bacillus spp. extracellular molecules upon bacterial challenge.

Stimulation of the fish immune system using immunostimulants is an environmentally friendly strategy to minimize bacterial outbreaks in aquaculture. Different biological and synthetic immunostimulants can enhance non-specific innate immune responses by directly activating immune cells. An example are Bacillus spp., known for their immunostimulatory effects, although the exact mechanisms by which Bacillus spp. offer protection against diseases remains to be elucidated. Furthermore, most studies have focused on Bacillus spp. cells, while the immunostimulant effect of their extracellular metabolome, known to harbour biologically important metabolites, including antimicrobial molecules, has been scarcely evaluated. Here, we evaluated the in vitro immune-modulatory properties of extracellular extracts of three Bacillus spp. strains (B. subtilis FI314, B. vezelensis FI436 and B. pumilus FI464), previously isolated from fish-guts and characterized for their in vitro and in vivo antimicrobial activity against a wide range of fish pathogens. Bacillus spp. extracellular extracts did not affect immune cells viability, but remarkably increased pathogens' phagocytosis when seabream head-kidney leukocytes were challenged with Vibrio anguillarum and Edwardsiella tarda. All extracts significantly increased the engulfment of bacterial pathogens 1 h post-infection. Cells stimulated with the extracellular extracts showed an up-regulation of the expression of immune-relevant genes associated with inflammation, including IL-1ß, IL-6, and COX-2. In cells challenged with E. tarda, FI314 extracellular extract significantly increased the expression of IL-1ß, IL-6, and COX-2, while FI436 and FI464 significantly increased IL-6 expression. The results of this study revealed that the extracellular molecules from Bacillus spp. fish isolates improved the in vitro response of gilthead seabream immune cells and are thus promising candidates to act as immunostimulants, helping fish fight diseases.

Current Evidence in Migraine Surgery: A Systematic Review.

INTRODUCTION: Migraine headache is a widespread neurovascular disorder with an enormous social and economic impact. A subgroup of patients cannot be managed with pharmacological therapy. Although surgical decompression of extracranial sensory nerves has been proposed as a valid alternative treatment option, the medical community remains reluctant to accept it. MATERIALS AND METHODS: This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. An electronic search was performed in September 2020 on PubMed, ScienceDirect, CENTRAL, and Google Scholar databases for original articles reporting outcomes on migraine surgery. RESULTS: The search strategy revealed a total of 922 studies, of which 52 were included in the review. Significant improvement was reported in 58.3% to 100% and complete elimination in 8.3% to 86.8% of patients across studies. No major complications were reported. DISCUSSION: This systematic review demonstrates that migraine surgery is an effective and safe procedure, with a positive impact in patients' quality of life and a reduction in long-term costs. CONCLUSION: There is considerable scientific evidence suggesting extracranial migraine surgery is an effective and safe procedure. This surgery should be considered in properly selected migraineurs refractory to medical treatment.

Bone and joint tuberculosis in paediatrics: a 13-year retrospective study.

Introduction. Bone and joint tuberculosis (BJTB) is rare in developed countries, particularly in the paediatric population.Hypothesis/Gap Statement. The clinical features and sequelae of paediatric BJTB in Europe are not well characterized and should be assessed to achieve a better approach.Aim. To assess the management and outcomes of paediatric BJTB.Methodology. Longitudinal observational study of all paediatric patients (0-17 years old) diagnosed with BJTB between 2008 to 2020 in a tertiary-care hospital.Results. We identified 18 patients with BJTB, with a median age of 10 years (IQR 6-14.8), 66.7 % male. Most (72 %) were diagnosed after 2015 and were foreign-born (88.9 %), mainly from Portuguese-speaking African countries, and none had HIV. The most common symptoms were pain (77.8 %), fever (50 %) and bone deformity (44.4 %). Spinal TB (STB) affected 13 (72.2 %) and extra-spinal TB (ESTB) 9 (50 %) patients, and 4 (27.7 %) had both conditions. Diagnostic positive procedures included positive nucleic acid amplification technique (NAAT) (44.4 %), Mycobacterium tuberculosis isolation (44.4 %) and compatible histology (33.3 %). All completed antituberculous drugs for a median of 12 months (IQR 12-13) and nine (50 %) had surgery. Overall, acute complications occurred in 16 (88.9 %) patients - 11/13 (84.6 %) with STB and 5/5 (100 %) with ESTB - and included abscesses, spinal compression, spine deformity and pathological fractures. Sequelae were still present at the 12-month follow-up in seven cases (46.7 %), and were more common in foreign-born patients sent to Portugal to receive medical treatment (66.7 vs 20 %).Conclusions. Paediatric BJTB is difficult to diagnose and has high morbidity, requiring long-term follow-up. Over the last decade, foreign-born TB seems to be increasing, with still longer treatment courses and more acute complications and sequelae.