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Antibiotics serve as the cornerstone of the treatment of bacterial diseases in the aquaculture sector. In this study, 210 Nile tilapias (Oreochromis niloticus) weighing approximately 60 ± 2.5 g b.w. were randomly divided into seven treatments (T1–7). The fish were experimentally infected with Aeromonas hydrophila and then treated with oxytetracycline (OTC) after the appearance of clinical symptoms. The fish were fed Moringa oleifera diet alone or M. oleifera diet before OTC treatment to alleviate the effects of OTC treatment. The effects of OTC treatment and M. oleifera were assessed by measuring the gene expressions of cytokines (interleukin [IL]‐1β, IL‐6, tumour necrosis factor‐α, IL‐10 and heat shock protein‐70), antioxidant enzymes (catalase, superoxide dismutase, lipid peroxidase and total antioxidant capacity) and liver enzymes (aspartate aminotransaminase, alanine aminotransaminase and alkaline phosphatase). Although OTC treatment protected fish from A. hydrophila, leading to a decreased mortality rate (49.96%), it exerted deleterious effects on their immune and oxidative statuses. Thus, we recommend that M. oleifera be included in the feed of O. niloticus, especially those exposed to bacterial infection. [ABSTRACT FROM AUTHOR]

Antibiotic‐resistant Aeromonas veronii isolates (4) were identified from moribund Oreochromis niloticus by phenotypic and genotypic characterization using 16S rDNA gene sequence analysis. Antibacterial efficacy of silver nanoparticles (AgNPs) was assessed in vitro and in vivo against A. veronii isolates. A minimum inhibitory concentration (MIC) and 48 h lethal concentration 50% (LC50) for AgNPs were estimated to be 3.125 μg/ml and 8.77 mg/L respectively. Four hundred fifty fish were divided into 10 groups in triplicate (15/replica). Two control groups were untreated with AgNPs: The first (G1) was not infected, whereas the second (G2) was experimentally infected with A. veronii. AgNPs were added to aquarium water with fish either noninfected (G3–G6) or infected (G7–G10) with A. veronii. AgNPs concentrations were 100, 250, 500 and 750 μg/L, respectively, for both sets of fish groups. Fish infected with A. veronii but untreated with AgNPs showed septicaemic symptoms, a high mortality rate (71%) and poorer haematological parameters (red blood cells [RBCs], haemoglobin concentration [Hb], hematocrit [HCT%], mean cell volume [MCV] and mean cell haemoglobin [MCH]); impaired nonspecific immune responses (total protein, albumin, globulin and lysozymes); reduced antioxidant capacity (catalase [CAT], peroxidase and superoxide dismutase [SOD]); a significant increase in creatinine, uric acid, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP); and genotoxic effects in gills. Treatment with AgNPs increased fish survival; improved haematological, immunological and antioxidant activities; and optimized liver and kidney function. The most favourable outcome was seen using an AgNPs concentration of 750 μg/L. Various histopathological changes were found among experimental fish. [ABSTRACT FROM AUTHOR]

The latest outbreak of a coronavirus disease in 2019 (COVID‐19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), evolved into a worldwide pandemic with massive effects on health, quality of life, and economy. Given the short period of time since the outbreak, there are several knowledge gaps on the comparative and zoonotic aspects of this new virus. Within the One Health concept, the current EAACI position paper dwells into the current knowledge on SARS‐CoV‐2's receptors, symptoms, transmission routes for human and animals living in close vicinity to each other, usefulness of animal models to study this disease and management options to avoid intra‐ and interspecies transmission. Similar pandemics might appear unexpectedly and more frequently in the near future due to climate change, consumption of exotic foods and drinks, globe‐trotter travel possibilities, the growing world population, the decreasing production space, declining room for wildlife and free‐ranging animals, and the changed lifestyle including living very close to animals. Therefore, both the society and the health authorities need to be aware and well prepared for similar future situations, and research needs to focus on prevention and fast development of treatment options (medications, vaccines). [ABSTRACT FROM AUTHOR]

Titanium dioxide nanoparticles (TiO2 NPs) are used in numerous products, such as paints, pharmaceuticals, environmental sanitizing agents and even as a whitening food additive (E171). Residual TiO2 NPs are considered among the emerging contaminants of aquatic environments. However, the effect of such exposure on intestinal microbiota population, microbial disease resistance and the immune-related gene expression of Nile tilapia (Oreochromis niloticus) is largely obscure. Three groups of fish were nurtured on diets containing 1 mg/ml TiO2 NPs with three different sizes (53, 31 and 13 nm), beside the control group for four weeks before sampling fish tissues. Fish groups fed on TiO2NPs diets showed significantly increased higher levels of tumour necrosis factor (TNF-α), interleukin (IL-6) and IL-1β, along with insignificant changes in IL-8 and IL-10 compared with the control group. These changes indicate a strong inflammatory response. Treated fish groups showed a marked decrease in the count of some intestinal microbiota, aeromonas, pseudomonas and lactobacillus. Fish were challenged against A. hydrophila, and a higher mortality rate was observed in the group fed on smaller TiO2 NPs (13 nm). The levels of antioxidant enzymes such as catalase, glutathione peroxidase and superoxide dismutase were significantly increased in groups fed on TiO2 NPs, while metallothionein levels were only slightly changed. In conclusion, feeding fish with diets containing TiO2 NPs (13 and 31 nm) for 4 weeks alters the intestinal microbiota population and provides additional information on the toxic impacts of TiO2 NPs on the health and immune status of O. niloticus. [ABSTRACT FROM AUTHOR]

Adverse reactions to insects occur in both human and veterinary patients. Systematic comparison may lead to improved recommendations for prevention and treatment in all species. In this position paper, we summarize the current knowledge on insect allergy induced via stings, bites, inhalation or ingestion, and compare reactions in companion animals to those in people. With few exceptions, the situation in human insect allergy is better documented than in animals. We focus on a review of recent literature and give overviews of the epidemiology and clinical signs. We discuss allergen sources and allergenic molecules to the extent described, and aspects of diagnosis, prophylaxis, management and therapy. [ABSTRACT FROM AUTHOR]

Bioassay-guided fractionation and chemical investigation of Colvillea racemosa stems led to identification of two new α, β -dihydroxydihydrochalcones, colveol A ( 1 ) and colveol B ( 2 ) along with fifteen known compounds. The structures were elucidated via interpretation of spectroscopic data. The absolute configurations of the dihydrochalcones 1 and 2 were assigned by a combination of chemical modification and electronic circular dichroism data. The isolated compounds were evaluated for their inhibition activity toward recombinant human monoamine oxidases (rhMAO-A and -B). Compound 1 demonstrated preferential inhibition against hMAO-A isoenzyme (IC 50 0.62 μM, SI A/B 0.02) while S -naringenin ( 13 ) and isoliquiritigein ( 15 ) demonstrated preferential hMAO-B inhibition (IC 50 0.27 and 0.51 μM, SI A/B 31.77 and 44.69, respectively). Fisetin ( 11) showed inhibition against hMAO-A with IC 50 value of 4.62 μM and no inhibitory activity toward hMAO-B up to 100 μM. Molecular docking studies for the most active compounds were conducted to demonstrate the putative binding modes. It suggested that 1 interacts with Gln215, Ala111, Phe352, and Phe208 amino acid residues which have a role in the orientation and stabilization of the inhibitor binding to hMAO-A, while S -naringenin ( 13 ) occupies both entrance and substrate cavities and interacts with Tyr326, a critical residue in inhibitor recognition in hMAO-B. [ABSTRACT FROM AUTHOR]

Snakebites worldwide represent a significant health hazard to humans and animals. Currently antivenom therapeutics is only the cure if given on proper time otherwise leads to death. The objective of this study was to evaluate the immunological effect of lactoferrin (Lf) in production of Naja nigricollis snake antibodies. Camel and cow milk whey were used as a source of 80 kDa Lf in a crude form and separated from milk whey using SDS-PAGE. This investigation was conducted through four experiments. In first experiment, we immunized of horses with N. nigricollis venom and camel milk whey; increased the anti-sera potency to (65 LD50) in comparison to the control group (45 LD50). For second experiment, we immunized of horses with the venom and cow milk whey which led to increase the anti-sera potency to (55.8 LD50) as compared to the control group (42.5 LD50). In the third experiment, using of standard bovine lactoferrin with the venom, the anti-sera potency increased to (75 LD50) as compared to the control group (50 LD50). In fourth experiment, we used of complete Freund's adjuvant with the venom; increase the anti-sera potency to (65 LD50) in compare to the control group (49.2 LD50). The immunological effect of lactoferrin was studied using Lymphocyte Transformation Test (LTT). The LTT mean values were 3.076±0.09 and 2.49±0.05 for the horses immunized with N. nigricollis venom / lactoferrin and the control group (horses injected with N. nigricollis venom without lactoferrin), respectively. This is the first study concluded that milk whey have the adjuvant effect on the antibodies levels and immunostimulatory effect in production of snake antisera from horses due to presence of lactoferrin. This specific property could be targeted as potential strategy for treatment of snake venom. [ABSTRACT FROM AUTHOR]

The ectonucleotidases CD39 and CD73 degrade immune stimulatory ATP to adenosine that inhibits T and NK cell responses via the A adenosine receptor (ADORA2A). This mechanism is used by regulatory T cells (T) that are associated with increased mortality in OvCA. Immunohistochemical staining of human OvCA tissue specimens revealed further aberrant expression of CD39 in 29/36 OvCA samples, whereas only 1/9 benign ovaries showed weak stromal CD39 expression. CD73 could be detected on 31/34 OvCA samples. While 8/9 benign ovaries also showed CD73 immunoreactivity, expression levels were lower than in tumour specimens. Infiltration by CD4 and CD8 T cells was enhanced in tumour specimens and significantly correlated with CD39 and CD73 levels on stromal, but not on tumour cells. In vitro, human OvCA cell lines SK-OV-3 and OaW42 as well as 11/15 ascites-derived primary OvCA cell cultures expressed both functional CD39 and CD73 leading to more efficient depletion of extracellular ATP and enhanced generation of adenosine as compared to activated T. Functional assays using siRNAs against CD39 and CD73 or pharmacological inhibitors of CD39, CD73 and ADORA2A revealed that tumour-derived adenosine inhibits the proliferation of allogeneic human CD4 T cells in co-culture with OvCA cells as well as cytotoxic T cell priming and NK cell cytotoxicity against SK-OV3 or OAW42 cells. Thus, both the ectonucleotidases CD39 and CD73 and ADORA2A appear as possible targets for novel treatments in OvCA, which may not only affect the function of T but also relieve intrinsic immunosuppressive properties of tumour and stromal cells. [ABSTRACT FROM AUTHOR]