A novel metabolite of Streptomyces coeruleorubidus exhibits antibacterial activity against Streptococcus agalactiae through modulation of physiological performance, inflammatory cytokines, apoptosis, and oxidative stress-correlated gene expressions in Nile tilapia (Oreochromis niloticus).

Using the unique structures found in natural materials to produce new antibacterial drugs is crucial. Actinobacteria is well-known for its ability to produce naturally occurring chemicals with a variety of structural features that can be used as weapons against infectious bacteria. In the present study, the Streptomyces coeruleorubidus metabolites were characterized and their efficacy in suppressing Streptococcus agalactiae growth was carried out both in vitro and in vivo. The metabolites of S. coeruleorubidus were purified and identified as octasiloxane-hexadecamethyl (OHM). In vivo antibacterial activity of OHM revealed an inhibitory minimum concentration value of 0.5 µg/ml against S. agalactiae and induced ultrastructural cell changes revealed by scanning electron microscope. The safe concentration of OHM was determined as 0.8 mg/L for Nile tilapia. Four in vivo treatments were treated with 0 and 0.8 mg/L OHM and with or without challenge by S. agalactiae (1 × 107 CFU/mL) named control, OHM, S. agalactiae, and S. agalactiae + OHM groups. The OHM treatment improved the survival of Nile tilapia by 33.33% than S. agalactiae challenge group. Waterborne OHM treatment significantly mitigated the deleterious effects of S. agalactiae on hematological, hepato-renal functions, stress indicators, and antioxidant balance. OHM significantly alleviated nitric oxide levels, complement 3, IgM, and lysozyme activity, downregulation of liver antioxidant genes expression in S. agalactiae group. Furthermore, the addition of OHM to challenged fish with S. agalactiae-significantly reversed dramatic negative regulation of inflammatory, apoptosis, and immune related gene expression (caspase-3, bax, pcna, tnf-α, ifn-γ, il-8 il-1ß, il-10, tgf-ß, and bcl-2 in the Nile tilapia spleen. Additionally, the damaged hepatic and splenic structure induced by bacterial infection was restored with OHM treatment. Finally, S. coeruleorubidus metabolites (mainly OHM) revealed in vitro and in vivo antibacterial activity and showed alleviated effects on the physiological status of S. agalactiae infected tilapia.

Dietary microalgal-fabricated selenium nanoparticles improve Nile tilapia biochemical indices, immune-related gene expression, and intestinal immunity.

BACKGROUND: Feed supplements, including essential trace elements are believed to play an important role in augmenting fish immune response. In this context, selenium nanoparticles (SeNPs) in fish diets via a green biosynthesis strategy have attracted considerable interest. In this investigation, selenium nanoparticles (SeNPs, 79.26 nm) synthesized from the green microalga Pediastrum boryanum were incorporated into Nile tilapia diets to explore its beneficial effects on the immune defense and intestinal integrity, in comparison with control basal diets containing inorganic Se source. Nile tilapia (No. 180, 54-57 g) were fed on three formulated diets at concentrations of 0, 0.75, and 1.5 mg/kg of SeNPs for 8 weeks. After the trial completion, tissue bioaccumulation, biochemical indices, antioxidant and pro-inflammatory cytokine-related genes, and intestinal histological examination were analyzed. RESULTS: Our finding revealed that dietary SeNPs significantly decreased (P < 0.05) serum alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and cholesterol, while increasing (P < 0.05) high-density lipoproteins (HDL). The Se concentration in the muscle tissues showed a dose-dependent increase. SeNPs at a dose of 1.5 mg/kg significantly upregulated intestinal interleukin 8 (IL-8) and interleukin 1 beta (IL-1ß) gene transcription compared with the control diet. Glutathione reductase (GSR) and glutathione synthetase (GSS) genes were significantly upregulated in both SeNPs-supplemented groups compared with the control. No apoptotic changes or cell damages were observed as indicated by proliferating cell nuclear antigen (PCNA) and caspase-3 gene expression and evidenced histopathologically. SeNPs supplementation positively affects mucin-producing goblet cells (GCs), particularly at dose of 1.5 mg/kg. CONCLUSION: Therefore, these results suggest that Green synthesized SeNPs supplementation has promising effects on enhancing Nile tilapia immunity and maintaining their intestinal health.

Phenotypic, molecular detection, and Antibiotic Resistance Profile (MDR and XDR) of Aeromonas hydrophila isolated from Farmed Tilapia zillii and Mugil cephalus.

In the present study, Aeromonas hydrophila was isolated from Tilapia zillii and Mugil cephalus samples collected during different seasons from various Suez Canal areas in Egypt. The prevalence of A. hydrophila, virulence genes, and antibiotic resistance profile of the isolates to the commonly used antibiotics in aquaculture were investigated to identify multiple drug resistance (MDR) and extensive drug-resistant (XDR) strains. In addition, a pathogenicity test was conducted using A. hydrophila, which was isolated and selected based on the prevalence of virulence and resistance genes, and morbidity of natural infected fish. The results revealed that A. hydrophila was isolated from 38 of the 120 collected fish samples (31.6%) and confirmed phenotypically and biochemically. Several virulence genes were detected in retrieved A. hydrophila isolates, including aerolysin aerA (57.9%), ser (28.9%), alt (26.3%), ast (13.1%), act (7.9%), hlyA (7.9%), and nuc (18.4%). Detection of antibiotic-resistant genes revealed that all isolates were positive for blapse1 (100%), blaSHV (42.1%), tetA (60.5%), and sul1 (42.1%). 63.1% of recovered isolates were considered MDR, while 28.9% of recovered isolates were considered XDR. Some isolates harbor both virulence and MDR genes; the highest percentage carried 11, followed by isolates harboring 9 virulence and resistance genes. It could be concluded that the high prevalence of A. hydrophila in aquaculture species and their diverse antibiotic resistance and virulence genes suggest the high risk of Aeromonas infection and could have important implications for aquaculture and public health.

Fishmeal substitution by zooplankton or Daphnia magna biomass meals in the diet of Nile tilapia: Effects on growth, gut histological changes, bacterial abundance and stress tolerance.

Fishmeal substitution with sustainable feed sources is highly essential towards sustainable production. This study aimed to investigate the effects of substituting fishmeal (FM) with Daphnia magna biomass meal (DBM) or zooplankton biomass meal (ZBM) on growth performance, liver and intestinal histology, gut bacterial abundance and stress tolerance of Nile tilapia, Oreochromis niloticus, fry. Nile tilapia fry (0.23 ± 0.04 g) were randomly assigned to five groups of three replicates. The control diet comprised 300 g/kg FM, and the FM was substituted with DBM or ZBM at levels of 25% and 50% (DBM-25, DBM-50, ZBM-25 and ZBM-50 respectively) in the other experimental diets. The experiment lasted 56 days in 1.5 m3 concrete tanks. The results revealed that weight gain and feed conversion ratio (FCR) significantly (p ≤ 0.035 and 0.025 respectively) improved with a polynomial response with a peak at 25% ZBM and a linear increase with DBM up to 50% of FM. Histometric indices of the distal intestine showed improvements (p ≤ 0.001) in villus height, villus width, crypt depth and muscle thickness of fish fed DBM or ZBM compared to the control. In the meantime, there were no histological abnormalities in the liver sections. The replacement of FM with DBM or ZBM could modulated gut bacterial abundance, including total bacterial count, Escherichia coli, Bacillus subtilis, and Lactobacillus sp. The fish-fed DBM or ZBM-containing diets had higher (p ≤ 0.05) tolerances to salinity stress than the control group. In conclusion, DBM or ZBM could replace FM up to 50% and 25%, respectively with improved fish growth performance, FCR, gut histology and tolerance to salinity stress.

Effects of extended dietary supplementation with Santalum album essential oil on hemato-biochemical changes, innate immune response, antioxidant status, and expression of related gene in Nile tilapia (Oreochromis niloticus).

The effects of long-term dietary supplementation with sandalwood (Santalum album L.) essential oil (SEO) was investigated on hemato-biochemical biomarkers, immune status, antioxidant capacity, and resistance against Staphylococcus aureus in Nile tilapia (Oreochromis niloticus). Five groups (with four replicates) of O. niloticus (12.60 ± 0.20 g) were fed diets supplemented with SEO at doses of 0, 0.5, 1.0, 2.0, and 4.0 mL/kg diet for 60 days. Results indicated a substantial increase in blood protein levels and lower serum cholesterol, cortisol, glucose, urea, creatinine levels and, transaminase activities of fish fed a 2.0-mL SEO/kg diet. Serum lysozyme activity, nitric oxide, complement-3 levels, and phagocytic activity were significantly improved in O. niloticus after 60 days of feeding SEO-supplemented diets. Dietary SEO at level of 2.0-mL SEO/kg diet increased the activities of SOD, CAT, and GPx, and decreased MDA levels in liver homogenate. In addition, dietary 2.0-mL SEO/kg diet significantly upregulated antioxidant genes expression (CAT, SOD, GPx, GST, and GSR) with downregulation of apoptotic genes (HSP70, TLR2, caspase-3, and PCNA) in the liver. Furthermore, SEO-enriched diets significantly down-regulated pro-inflammatory (TNF-α, IL-1ß, and IL-8) and up-regulated anti-inflammatory cytokine genes (TFG-ß and IL-10) in the spleen. Moreover, SEO fortification increased the relative percentage of survival against S. aureus challenge and regulated immune-antioxidant genes in the spleen after the challenge. Overall, the results revealed that long-term using SEO might strengthen the physiological performance, hepatic oxidant/antioxidant balance, innate immune response, and resistance of O. niloticus against bacterial infections.

Phytochemical and Potential Properties of Seaweeds and Their Recent Applications: A Review.

Since ancient times, seaweeds have been employed as source of highly bioactive secondary metabolites that could act as key medicinal components. Furthermore, research into the biological activity of certain seaweed compounds has progressed significantly, with an emphasis on their composition and application for human and animal nutrition. Seaweeds have many uses: they are consumed as fodder, and have been used in medicines, cosmetics, energy, fertilizers, and industrial agar and alginate biosynthesis. The beneficial effects of seaweed are mostly due to the presence of minerals, vitamins, phenols, polysaccharides, and sterols, as well as several other bioactive compounds. These compounds seem to have antioxidant, anti-inflammatory, anti-cancer, antimicrobial, and anti-diabetic activities. Recent advances and limitations for seaweed bioactive as a nutraceutical in terms of bioavailability are explored in order to better comprehend their therapeutic development. To further understand the mechanism of action of seaweed chemicals, more research is needed as is an investigation into their potential usage in pharmaceutical companies and other applications, with the ultimate objective of developing sustainable and healthier products. The objective of this review is to collect information about the role of seaweeds on nutritional, pharmacological, industrial, and biochemical applications, as well as their impact on human health.

Moringa oleifera alleviated oxidative stress, physiological and molecular disruption induced by acute thermal stress in grass carp, Ctenopharyngodon idella.

The present study was designed to investigate the protective effect of dietary Moringa oleifera leaf meal (MLM) supplementation against high temperature-induced stress in grass carp (Ctenopharyngodon idella). A total of 180 apparent healthy juvenile grass carp (15.48 g ± 0.054) were divided into three groups in triplicate (20 fish in each replicate). Fish were fed with diets containing 0, 1, and 5% MLM for 60 days and then subjected to a high-temperature challenge for 48 h (32-33 °C). The results revealed that feeding fish with 1 and 5% MLM resulted in a significant increase in weight gain and specific growth rate compared to the control. In addition, feed conversion ratio was significantly reduced in groups fed with MLM. No significant difference was reported in the serum cortisol level among different experimental groups before heat stress while serum glucose level significantly decreased in fish fed with 5% MLM. Serum alanine transaminase, aspartate transaminase, and alkaline phosphatase significantly decreased in fish fed with 1 and 5% MLM before and after heat stress. Hepatic lipid peroxidation significantly decreased in fish fed with MLM for 60 days. A non-significant increase in hepatic reduced glutathione level was reported in fish fed with 1 and 5% MLM before heat stress. Catalase and superoxide dismutase activities increased significantly in the liver of fish fed with 5% MLM. No significant change was observed in the expression profile of heat shock protein (hsp) 70 and 90 before heat stress. Meanwhile, after heat stress, up to a fivefold increase was recorded in mRNA level of hsp 70 and fourfold increase in the expression level of hsp 90 in the liver of the control fish which were not fed with MLM-supplemented diets. Fish fed with 1 and 5% MLM showed a significant decrease in the expression of hsp 70 and a non-significant decrease in the expression of hsp 90. Results of the present study suggest that supplementing the diet of grass carp with 5% MLM could improve growth and physiological performance and provide resistance against high temperature-induced stress.

Effects of aqueous and ethanolic leaf extracts from drumstick tree (Moringa oleifera) on gilthead seabream (Sparus aurata L.) leucocytes, and their cytotoxic, antitumor, bactericidal and antioxidant activities.

Aqueous and ethanolic extracts of drumstick, Moringa oleifera, leaves were evaluated in vitro to ascertain their principal active components and determine their immunostimulant, cytotoxic, antitumoral, bactericidal and antioxidant activities. Phytochemical screening of M. oleifera leaf extracts showed a greater abundance of phenolic and cyanogenic glycosides in aqueous than in ethanolic extracts, characterized by several flavonoids, condensed tannins and saponins. No significant effects on gilthead seabream (Sparus aurata) head-kidney leucocyte activities (phagocytic ability and capacity, respiratory burst and peroxidase) were detected after incubation for 24 h with different concentrations (0.001/1 mg mL-1) of either extract. In addition, the aqueous extract showed a marked cytotoxic effect on both SAF-1 (at doses above 0.01 mg mL-1) and PLHC-1 (at doses above 0.25 mg mL-1) cell lines. The ethanolic extract improved the viability of SAF-1 cells and decreased the viability of PLHC-1 cells when used at higher concentrations. Both the ethanolic and, particularly, the aqueous extracts showed significant bactericidal activity on pathogenic Vibrio anguillarum and Photobacterium damselae strains. The antiradical activity of M. oleifera, as determined by the ABTS assay, increased in a linear dose-response with increasing extract concentrations. The results as a whole for the cytotoxic, bactericidal and antioxidant activities of M. oleifera leaf extracts point to their possible use as additives in functional diets for farmed fish.

Dietary supplementation of drumstick tree, Moringa oleifera, improves mucosal immune response in skin and gills of seabream, Sparus aurata, and attenuates the effect of hydrogen peroxide exposure.

In aquatic animals, the mucosal barrier is the first line of innate immune defence against external chemicals and pathogens. In this study, the effects of dietary Moringa oleifera leaf (MOL) supplementation on skin and gill mucosal immunity, antioxidants and stress responses were evaluated in seabream (Sparus aurata) fingerlings exposed to hydrogen peroxide (H2O2). A total of 144 specimens (10.11 ± 0.41 g) were divided into four treatments (three replicates per treatment contained 12 specimens each) and fed a non-supplemented control diet or a 1, 2.5 or 5% MOL-supplemented diet. After three weeks of feeding, six specimens from each aquarium were sampled for blood, mucus and tissues. The other six fish in each aquarium were subjected to H2O2 exposure. The results revealed that MOL did not negatively affect either cortisol or glucose levels. MOL supplementation significantly (P < 0.05) improved skin mucosal immunity-related characteristics, including phosphatase, peroxidase and lysozyme activity and IgM levels. Additionally, MOL upregulated the expression of antioxidant genes (sod and cat), an anti-inflammatory gene (tgf-ß), tight junction protein genes (occludin and zo-1), c3, and igm in both the skin and gills. However, H2O2 exposure significantly (P < 0.05) increased both cortisol and glucose levels and disrupted skin mucosal immune function by significantly (P < 0.05) decreasing phosphatase, peroxidase, protease, antiprotease and lysozyme activity and IgM levels. H2O2 exposure severely decreased the mRNA levels of the studied genes. MOL dietary supplementation at the 5% level successfully attenuated the negative effects of H2O2 on the mucosal immune response in both the skin and gills. In conclusion, dietary MOL supplementation at the 5% level is recommended to improve S. aurata mucosal immune function under both normal and stress conditions. Additionally, exposure to H2O2 disrupts the mucosal immunity of fish. This contributes knowledge on the routes involved in mucosal innate immunity and could help to understand the fish resistance against chemicals exposure. Graphical abstract.

Effects of dietary inclusion of Moringa oleifera leaves on growth and some systemic and mucosal immune parameters of seabream.

The effect of the dietary incorporation of drumstick, Moringa oleifera, leaf meal (MOL; 0, 5, 10 and 15%) on the growth, feed utilization, some skin mucus and systemic immune parameters and intestinal immune-related gene expression in gilthead seabream (Sparus aurata) specimens. The experiment lasted 4 weeks. The results revealed that MOL can be incorporated in S. aurata diet up to 10% with no significant negative effect on growth and feed utilization. However, there was a significant decrease with MOL at a level of 15% after 2 weeks of feeding. The systemic immune status of fish fed with the different levels of MOL showed an improvement in head kidney leucocyte phagocytosis, respiratory burst and peroxidase activities. Also, serum humoral components, including protease, ACH50 and lysozyme activities and IgM level, increased with MOL inclusion especially at the 5% level. MOL at 5% improved skin-mucosal immunity such as protease, antiprotease, peroxidase and lysozyme activities. Moreover, the feeding of MOL revealed an upregulation of the intestinal mucosal immunity genes (lyso and c3), tight junction proteins (occludin and zo-1) and anti-inflammatory cytokines (tgf-ß) with a downregulation of pro-inflammatory cytokine (tnf-α). Therefore, it is recommended to incorporate MOL in S. aurata diets at a level of 5% for the best immune status or 10% for the high growth performance and acceptable immune surveillance. Graphical abstract ᅟ.

Dietary supplementation of organic selenium improves growth, survival, antioxidant and immune status of meagre, Argyrosomus regius, juveniles.

Oxidative stress is considered one of the main obstacles to immune competence and high mortality rate of marine fish larvae due to the high dietary polyunsaturated fatty acids and accelerated metabolic rate. This study was carried out to assess the effect of different dietary selenium (Se) yeast on growth, antioxidant status, hematological changes, and cellular and humoral immune parameters in meagre (Argyrosomus regius). Juvenile specimens (3.20 ± 0.17 g) were randomly assigned to four experimental groups, a control group fed a basal diet and another three groups fed Se-supplemented diets at doses of 1, 2 and 3 mg Se-yeast kg-1 diet for 63 days and the final analyzed selenium concentrations were 0.77, 1.51, 2.97 and 3.98 mg Se kg-1 diet, respectively. The results indicated that growth performance, feed conversion ratio and survival were significantly improved with 2.97 and 3.98 mg Se-yeast kg-1 compared to the control group. The catalase, superoxide dismutase activities and total antioxidant status were significantly increased, and thiobarbituric reactive substances in liver homogenate were significantly decreased with increasing Se supplementation respect to the control fish in a dose-dependent manner. Furthermore, hematological and innate immune parameters (immunoglobulin, lysozyme, myeloperoxidase, ACH50 and respiratory burst activity) were also significantly higher in fish fed the Se-yeast supplemented diets compared to the control group. The results demonstrated that the supplementation of 3.98 mg Se-yeast kg-1 diet improves growth performance, antioxidant balance and innate immune status of meagre juveniles.

Usage of Chlorella and diverse microalgae for CO2 capture - towards a bioenergy revolution.

To address climate change threats to ecosystems and the global economy, sustainable solutions for reducing atmospheric carbon dioxide (CO2) levels are crucial. Existing CO2 capture projects face challenges like high costs and environmental risks. This review explores leveraging microalgae, specifically the Chlorella genus, for CO2 capture and conversion into valuable bioenergy products like biohydrogen. The introduction section provides an overview of carbon pathways in microalgal cells and their role in CO2 capture for biomass production. It discusses current carbon credit industries and projects, highlighting the Chlorella genus's carbon concentration mechanism (CCM) model for efficient CO2 sequestration. Factors influencing microalgal CO2 sequestration are examined, including pretreatment, pH, temperature, irradiation, nutrients, dissolved oxygen, and sources and concentrations of CO2. The review explores microalgae as a feedstock for various bioenergy applications like biodiesel, biooil, bioethanol, biogas and biohydrogen production. Strategies for optimizing biohydrogen yield from Chlorella are highlighted. Outlining the possibilities of further optimizations the review concludes by suggesting that microalgae and Chlorella-based CO2 capture is promising and offers contributions to achieve global climate goals.

Effect of dietary intervention with Capsicum annuum extract on growth performance, physiological status, innate immune response, and related gene expression in Nile tilapia.

The red pepper (Capsicum annuum) has gained great attention recently because of its biological and pharmacological characteristics. The present approach aimed to evaluate the effects of C. annuum alcoholic extract (CAE) supplementation on Nile tilapia (Oreochromis niloticus) growth performance, physiological status, some metabolic, immune, and regulatory genes expression, and resistance against Streptococcus agalactiae infection. Fish (22.26 ± 0.19 g) were assigned to four treatments (five replicates, each with 10 fish replicate-1) and fed tested diets for 60 days. The experimental diets were supplemented with CAE at 0, 0.4, 0.8, and 1.6 g kg-1, expressed as CAE0, CAE0.4, CAE0.8, and CAE1.6, respectively. The findings exhibited that CAE dietary supplementation improved growth performance, feed utilization, elevated growth hormone level, and digestive enzyme activities (amylase and protease), and lowered leptin hormone in a level-dependent manner. Boosting the mRNA expression of the transporter proteins (solute carrier family 15 member 2 and solute carrier family 26 member 6) and insulin-like growth factor-1 genes with a decrease in the myostatin gene expression was noticed in the CAE-fed groups. The innate immune (serum bactericidal activity %, complement 3, and phagocytic activity %) and antioxidant (glutathione peroxidase and total antioxidant capacity) parameters were significantly (p < 0.05) improved, and the serum malondialdehyde level was significantly decreased by CAE dietary inclusion. A marked upregulation in the mRNA expression of interleukins (il-1ß, il-6, il-8, and il-10), transforming growth factor-ß, glutathione peroxidase, and glutathione synthetase genes were observed in CAE-fed groups. Dietary CAE decreased the cumulative mortalities after the challenge with S. agalactiae by 20, 13.33, and 10% in CAE0.4, CAE0.8, and CAE1.6, respectively, compared to the control (40%). Overall, dietary supplementation with CAE could improve growth performance and physiological status, and modulate the expression of several regulatory genes in Nile tilapia. The recommended level of CAE is 1.6 g kg-1 to augment growth and health status.

Effects of α-sitosterol on growth, hematobiochemical profiles, immune-antioxidant resilience, histopathological features and expression of immune apoptotic genes of Nile tilapia, Oreochromis niloticus, challenged with Candida albicans.

In this study, the effect of the Streptomyces misakiensis metabolite (α- sitosterol, 0, 20, 40, 60, and 80 mg/kg) dietary supplementation on growth performance, antioxidant-immune stability and Candida albicans resistance of Nile tilapia was evaluated. The results revealed that the incorporation of α-sitosterol at doses of 60 and 80 mg/kg into the diet significantly improved the growth rate of Nile tilapia. The fish receiving 80 mg/kg showed an increased level of high-density lipoprotein, total protein, globulin, and albumin, and significantly reduced levels of indicators of hepato-renal damage, glucose, triglycerides, low-density lipoprotein, and total cholesterol. Dietary α-sitosterol induced a considerable increase in hepatopancreas glutathione peroxidase, superoxide dismutase and catalase activities and a significant drop in malondialdehyde levels. Supplementing the diet with 80 mg/kg of α-sitosterol increased nitric oxide, complement-3, nitro blue tetrazolium levels, lysozyme, and phagocytic activities. In particular, supplementing with α-sitosterol at 60-80 mg/kg of diet significantly enhanced the expression of pro/anti-inflammatory markers (il1b, il10, tgfb, ifng, tnfa and il8) after the C. albicans challenge. Also, there was a decrease in cumulative mortality percent, pro-apoptotic markers (casp3, bax and hsp70) and an increase in anti-apoptotic indicators (bcl2). Interestingly, following the C. albicans challenge, fish that received 0 and 20 mg α-sitosterol/kg exhibited significant inflammation in the hepatopancreas, spleen, and intestine. On the other hand, inflammation could be alleviated by feeding 60-80 mg α-sitosterol/kg. Due to these findings, α-sitosterol could be an innovative option to enhance growth, general physiological status, immune service, and antifungal resistance of Nile tilapia against C. albicans.

Proven anti-virulence therapies in combating methicillin- and vancomycin-resistant Staphylococcus aureus infections.

Introduction: Despite years of efforts to develop new antibiotics for eradicating multidrug-resistant (MDR) and multi-virulent Methicillin-Resistant Staphylococcus aureus (MRSA) and Vancomycin-Resistant Staphylococcus aureus (VRSA) infections, treatment failures and poor prognoses in most cases have been common. Therefore, there is an urgent need for new therapeutic approaches targeting virulence arrays. Our aim is to discover new anti-virulence therapies targeting MRSA and VRSA virulence arrays. Methodology: We employed phenotypic, molecular docking, and genetic studies to screen for anti-virulence activities among selected promising compounds: Coumarin, Simvastatin, and Ibuprofen. Results: We found that nearly all detected MRSA and VRSA strains exhibited MDR and multi-virulent profiles. The molecular docking results aligned with the phenotypic and genetic assessments of virulence production. Biofilm and hemolysin productions were inhibited, and all virulence genes were downregulated upon treatment with sub-minimum inhibitory concentration (sub-MIC) of these promising compounds. Ibuprofen was the most active compound, exhibiting the highest inhibition and downregulation of virulence gene products. Moreover, in vivo and histopathological studies confirmed these results. Interestingly, we observed a significant decrease in wound area and improvements in re-epithelialization and tissue organization in the Ibuprofen and antimicrobial treated group compared with the group treated with antimicrobial alone. These findings support the idea that a combination of Ibuprofen and antimicrobial drugs may offer a promising new therapy for MRSA and VRSA infections. Conclusion: We hope that our findings can be implemented in clinical practice to assist physicians in making the most suitable treatment decisions.

Antagonistic Effect of Zinc Oxide Nanoparticles Dietary Supplementation Against Chronic Copper Waterborne Exposure on Growth, Behavioral, Biochemical, and Gene Expression Alterations of African Catfish, Clarias gariepinus (Burchell, 1822).

The harmful impact of waterborne copper (Cu) as a common abiotic stressor in aquatic environments has gained much more interest. The present study aimed to investigate the utilization of zinc oxide nanoparticles (ZnONPs) dietary supplementation to mitigate the chronic toxicity of Cu in African catfish (Clarias gariepinus). Two hundred and forty fish (92.94 ± 0.13 g) were assigned into six groups for 60 days. Control (C), ZnONPs20, and ZnONPs30 groups were fed on basal diets fortified with 0, 20, and 30 mg kg-1 ZnONPs without Cu exposure. Cu, Cu + ZnONPs20, and Cu + ZnONPs30 groups were exposed to Cu at a dose of 10 mg L-1 and fed on basal diets fortified with 0, 20, and 30 mg kg-1 ZnONPs, respectively. The results revealed that the Cu-exposed fish experienced abnormal clinical signs and behavioral changes. The growth indices and acetylcholine esterase activity were significantly decreased (P < 0.05) in the Cu group. Meanwhile, hepatorenal and serum stress indices (P < 0.05) were significantly elevated with chronic Cu exposure. In addition, a higher expression of stress (P < 0.05) (heat shock protein 60 and hypoxia-inducible factor-1 alpha) and apoptotic-related genes (C/EBP homologous protein, caspase-3, and Bcl-2 Associated X-protein) with down-regulation (P < 0.05) of the anti-apoptotic-related genes (B-cell lymphoma 2 and proliferating cell nuclear antigen) was noticed in the Cu-exposed fish. Histopathological alterations in the gills, liver, kidney, and spleen were markedly reported in the Cu-exposed group. The dietary supplementation with ZnONPs significantly alleviated the negative impacts of chronic waterborne-Cu exposure on growth performance, physiological changes, gene expression, and tissue architecture, especially at 30 mg kg-1 diet level. In particular, the inclusion of ZnONPs at the 30 mg kg-1 diet level produced better outcomes than the 20 mg kg-1 diet. Overall, ZnONPs could be added as a feed supplement in the C. gariepinus diet to boost the fish's health and productivity and alleviate the stress condition brought on by Cu exposure.

Effects of tea tree oil and cefepime treatments on morphological, genetic, histopathological, immunohistochemistry, and biochemical assessments in liver and kidney of Escherichia coli infected rats.

The current study evaluated the influence of the treatment with tea tree oil and cefepime on morpho- genetic, histo-immunohistochemical, and biochemical assessments in rats experimentally challenged with Escherichia coli ATCC 4157™. Thirty adult male rats were divided into control, E. coli infected positive group (1×108CFU/I/P/once), E. coli with cefepime-supplemented group (45 mg/kg bw/I/M/day), E. coli with tea tree oil treated group (1.5 ml/per os/day), and the E. coli-challenged group that received a combination of tea tree oil and cefepime. E. coli infection induced morphological changes in color and texture of both liver and kidney. The transcription levels of the PHLPP2 and Nrf2 genes were noticeably lowered in all treated groups related to the E. coli group. Regarding the TLR4 expression, it was clearly up-regulated in the E. coli group in comparison to other groups, while CD14 gene decreased clearly in all treated groups compared to the positive group. The findings revealed that RBC, HGB, and PCV were clearly higher in the positive group compared to all treated groups. AST, ALT, and ALP, total bilirubin and its fractions, urea, and creatinine maximized in the positive group and decreased by the treatment, especially in the E+CF+oil treated group. Regarding the redox balance, MDA levels of MDA were notably reduced in the E+CF+oil treated group compared to the positive and the other treated groups. GSH, SOD, and GPX were significantly induced in the E. coil-treated group and decreased significantly with treatment. Overall, cefepime is highly safe especially when dually supplied with tea tree oil for mitigating E. coli adverse impact.

Antioxidant, Immunostimulant, and Growth-Promoting Effects of Dietary Annona squamosa Leaf Extract on Nile Tilapia, Oreochromis niloticus, and Its Tolerance to Thermal Stress and Aeromonas sobria Infection.

Plant extracts are a phytochemically-rich alternative to antibiotic and synthetic feed additives, with high systemic bioactivity in animals. The present study aimed to evaluate the effect of a hydroalcoholic extract of custard apple (Annona squamosa) leaf (ASLE) on the growth, hematobiochemical parameters, digestive enzyme activities, redox status, nonspecific immune response, and cold and bacterial infection tolerance in Nile tilapia (Oreochromis niloticus). A total of 300 Nile tilapia fingerlings (11.87 ± 0.48 g) were fed ASLE-supplemented diets at increasing levels of 0, 5, 10, 15, and 20 g/kg for 60 days. At the end of the feeding period, the fish were experimentally challenged with cold water stress or Aeromonas sobria, and mortalities were recorded for 10 days. The results revealed that the growth performance and feed conversion ratio were significantly improved with an increasing level of ASLE supplementation. The hematologic profile and hepato-renal functions were retained within a healthy range in the various groups supplemented with an ASLE diet. Antioxidant status was significantly improved in the serum of fish fed ASLE-supplemented diets, in terms of superoxide dismutase (SOD), catalase (CAT) activities, reduced glutathione, and total antioxidant capacity. Meanwhile, the myeloperoxidase (MPO) and malondialdehyde (MDA) levels decreased significantly. Similarly, there was a noticeable improvement in the hepatic CAT and SOD activities and a reduction of hepatic MDA. Marked improvements in lysozyme activity, nitric oxide production, complement3 level, and phagocytic activity were recorded in groups fed ASLE-supplemented diets, which peaked with the 20 g ASLE/kg diet. Moreover, the serum glucose and cortisol levels significantly declined in groups fed ASLE at levels of 15-20 g/kg compared to the other groups. Supplementation with ASLE increased the activities of protease, lipase, and α-amylase. ASLE supplementation at a concentration of 10-20 g/kg diet enhanced the resistance of Nile tilapia to A. sobria infection. According to this study, ASLE supplementation enhanced the antioxidant balance, non-specific immune response, physiological status, resistance against infection, and growth performance of Nile tilapia at supplementation levels of 10-20 g/kg diet.

Algal Extracts for Green Synthesis of Zinc Oxide Nanoparticles: Promising Approach for Algae Bioremediation.

Zinc oxide nanoparticles (ZnO-NPs) possess unique properties, making them a popular material across various industries. However, traditional methods of synthesizing ZnO-NPs are associated with environmental and health risks due to the use of harmful chemicals. As a result, the development of eco-friendly manufacturing practices, such as green-synthesis methodologies, has gained momentum. Green synthesis of ZnO-NPs using biological substrates offers several advantages over conventional approaches, such as cost-effectiveness, simplicity of scaling up, and reduced environmental impact. While both dried dead and living biomasses can be used for synthesis, the extracellular mode is more commonly employed. Although several biological substrates have been successfully utilized for the green production of ZnO-NPs, large-scale production remains challenging due to the complexity of biological extracts. In addition, ZnO-NPs have significant potential for photocatalysis and adsorption in the remediation of industrial effluents. The ease of use, efficacy, quick oxidation, cost-effectiveness, and reduced synthesis of harmful byproducts make them a promising tool in this field. This review aims to describe the different biological substrate sources and technologies used in the green synthesis of ZnO-NPs and their impact on properties. Traditional synthesis methods using harmful chemicals limit their clinical field of use. However, the emergence of algae as a promising substrate for creating safe, biocompatible, non-toxic, economic, and ecological synthesis techniques is gaining momentum. Future research is required to explore the potential of other algae species for biogenic synthesis. Moreover, this review focuses on how green synthesis of ZnO-NPs using biological substrates offers a viable alternative to traditional methods. Moreover, the use of these nanoparticles for industrial-effluent remediation is a promising field for future research.

Exposure to oxyfluorfen-induced hematobiochemical alterations, oxidative stress, genotoxicity, and disruption of sex hormones in male African catfish and the potential to confront by Chlorella vulgaris.

The present study evaluated the effect of chronic exposure to oxyfluorfen (OXY) on different physiological responses of male African catfish, Clarias gariepinus, and the ameliorative effect of Chlorella vulgaris. The fish (160 ± 5.10 g) were exposed to 1/20 LC50 of OXY (0.58 mg/L) for 60 consecutive days with or without co-administration of C. vulgaris (25 g/kg diet) in triplicate groups. The results revealed that chronic exposure to a sublethal level of OXY induced severe anemia and leukopenia. OXY-exposed fish experienced hypoproteinemia, marked lower AchE levels, and a significant increase in glucose, liver, and kidney function biomarkers. The DNA fragmentation of the liver increased by 15 % in fish compared to the control. On the other hand, lipid peroxidation, superoxide dismutase, and catalase activities were markedly increased in the liver and testes homogenates of the OXY-exposed fish. Meanwhile, total antioxidant capacity and glutathione S-transferase levels declined in the same tissues. Exposure to OXY induced a significant reduction in testosterone and luteinizing hormone levels and a significant increase in follicle stimulating hormone and estradiol. Meanwhile, C. vulgaris dietary supplementation succeeded in alleviating the negative impact of OXY on hematobiochemical parameters and restoring the antioxidant balance in the liver and testes. Furthermore, it ameliorated endocrine disruption and repaired sex hormone levels. In conclusion, exposure to OXY could induce systemic stress, oxidative stress, and endocrine disruption in male C. gariepinus. The dietary supplementation of C. vulgaris could be a potential protective strategy against the toxicity of OXY.