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[Transketolase activity in thiamine deficiency of the kidney in rainbow trout (Salmo gairdneri) following continous feeding with raw hearring].

The feeding of crude, thiaminase-containing herring to rainbow trout produced external symptoms of thiamine deficiency after a period of 150 days. The level of transketolase activity in the kidney decreased continuously until the first appearance of deficiency symptoms, while the TPP effect showed an upward trend. After prolonged feeding of crude herring the decline of transketolase activity is accompanied by a deficiency of the apoenzyme of transketolase. The administration of thiamine-containing food to the thiamine-deficient animals induced an immediate increase n transketolase activity. On…

Chronic Cortisol Exposure Reshapes Chromatin Accessibility and Gene Expression: Implications for Growth and Welfare in Rainbow Trout (Oncorhynchus mykiss).

Cortisol, the principal glucocorticoid in teleosts, coordinates the physiological response to stress by regulating metabolism, protein turnover, and growth. Although the molecular effects of acute cortisol exposure have been extensively characterized, the epigenomic mechanisms underlying skeletal muscle remodeling during prolonged cortisol elevation remain poorly understood. Here, we investigated how chronic cortisol reshapes chromatin accessibility and gene expression in rainbow trout (Oncorhynchus mykiss) skeletal muscle using an integrative ATAC-seq and RNA-seq approach. Fish received a sin…

Protective effects of gamma-irradiated ice-nucleating Pseudomonas syringae on quality loss in rainbow trout during freeze-thaw cycles.

This study investigated the protective effects of gamma-irradiated ice-nucleating Pseudomonas syringae, known as P. syringae parabiotics (PBs), on the freezing behavior, physicochemical quality, and microstructural integrity of rainbow trout mince during six freeze-thaw (F-T) cycles. PBs were added to the mince at levels of 2 × 102 to 2 × 104 inactivated cells/g and compared with the viable cell treatment (2 × 103 CFU/g). The results demonstrated a pronounced protective effect of 2 × 102 inactivated cells/g (PBs-2) and 2 × 103 inactivated cells/g (PBs-3) during repeated F-T cycles. PBs-2 exhib…

Nitrate bioaccumulation, growth performance and survival of rainbow trout (Oncorhynchus mykiss) in aquaponics with elevated water NO3-N levels.

Aquaponics systems offer a sustainable method for the combined production of fish and plants, but they may lead to elevated nitrogenous compounds in water to satisfy plant nitrogen requirements. However, limited information is available on nitrate accumulation in fish flesh under increased nitrate nitrogen (NO3-N) conditions. This study assessed the performance of rainbow trout reared in an aquaponics system exposed to NO3-N levels exceeding optimal thresholds. Although water NO3-N concentrations surpassed recommended values, nitrate levels in fish flesh remained low and within acceptable food…

Evaluating the Processing and Nutrient Digestibility of Defatted Nannochloropsis sp. QH25 Co-Product for Sustainable Rainbow Trout Aquaculture Diets.

The sustainability limitations of fishmeal and fish oil have increased interest in nutrient- rich microalgal co-products for aquafeeds. This study evaluated the effects of processing on the nutritional composition and apparent digestibility of a defatted Nannochloropsis sp. QH25 co-product in rainbow trout (Oncorhynchus mykiss). Experiment 1 assessed the effects of extrusion at 90 °C or 127 °C, with or without precooking, and enzymatic treatment with protease, xylanase, and β-glucanase. Based on nutrient composition, the 90 °C extrusion treatment without precooking was selected for Experiment …

Comparative evaluation of muscle quality, nutritional composition, and flavor in rainbow trout (Oncorhynchus mykiss) cultured between freshwater and seawater.

Rainbow trout is an important fish species that can be cultured in both freshwater and seawater. Nevertheless, its muscle quality has not been systematically evaluated until now. This study was conducted for the comparison of meat quality in rainbow trout cultured between freshwater and seawater. Results showed that seawater significantly improved growth performance and muscle hardness, gumminess, and chewiness. It also promoted the accumulation of Na+, Cl-, Ca2+, and sweet-tasting amino acids. In addition, seawater-cultured rainbow trout had higher contents of unsaturated fatty acids and inos…

Bacterial Isolates Associated with Mortality Events in Brown Trout (Salmo trutta) Restocking Farms in Spain: A Descriptive Field Study.

This study aimed to identify bacterial isolates associated with mortality events in Salmo trutta rearing farms in Spain and to assess their … monitoring to mitigate bacterial diseases and limit the spread of antimicrobial resistance in brown trout farming. These findings align with a One Health perspective, linking aquaculture practices, ecosystem integrity, and public health.

Early metabolic and transcriptomic regulation in rainbow trout (Oncorhynchus mykiss) liver by 11-deoxycorticosterone through two corticosteroid receptors pathways.

Cortisol hormone is considered the main corticosteroid in fish stress, acting through glucocorticoid (GR) or mineralocorticoid (MR) receptor. The 11-deoxycorticosterone (DOC) corticosteroid is also secreted during stress and could complement the cortisol effects, but this still not fully understood. Hence, we evaluated the early transcriptomic response of rainbow trout (Oncorhynchus mykiss) liver by DOC through GR or MR. Thirty juvenile trout were pretreated with an inhibitor of endogenous cortisol synthesis (metyrapone) by intraperitoneal injection in presence or absence of GR (mifepristone) …

Рекомбинантный аденовирус, нацеленный на типичную Aeromonas лососевицику, вызывает адаптивную иммунную реакцию на антитела после иммунизации радужной форели.

Aeromonas лососьицида, самый старый известный патоген рыбы, который в настоящее время является эндемичным во всем мире как в пресной, так и в морской воде, причиняет серьезные экономические потери земледельчеству. Несмотря на то, что за последние несколько десятилетий было проведено много исследований по вопросу о предотвращении фураскоза, он по-прежнему распространен во многих рыболовецких промыслах. В этом исследовании была успешно разработана и опробована рекомбинантная аденовирусная вакцина, содержащая высокоиммуногенный ген Вапа (pad-easy-cmv-Vapa). Затем после иммунизации радужной форели

Совпадение в аннотации оригинала
Aeromonas salmonicida, the oldest known fish pathogen and currently endemic throughout most of the world in both fresh and marine waters, ca … and specific antibody levels in the peripheral blood were then determined after immunizing rainbow trout. In addition, relative levels of IgM and IgT in the head kidney and hindgut before and after immunization were measured by quantitative reverse transcription PCR. Western blotting results indicated that the recombinant adenovirus could infect HEK-29 …

Rainbow Trout Erythrocytes ex vivo Transfection With a DNA Vaccine Encoding VHSV Glycoprotein G Induces an Antiviral Immune Response.

Fish red blood cells (RBCs), are integral in several biologic processes relevant to immunity, such as pathogen recognition, pathogen binding … e of fish RBCs in immune responses induced by DNA vaccines. We show for the first time that rainbow trout RBCs express gpG of viral hemorrhagic septicaemia virus (VHSV) (GVHSV) when transfected with the DNA vaccine ex vivo and modulate the expression of immune genes and proteins. Functional network analysis of transcriptome profiling of RBCs expressing …

Isolation characterization, virulence potential of Weissella ceti responsible for weissellosis outbreak in rainbow trout (Oncorhynchus mykiss) cultured in Mexico.

Weissella ceti, a Gram-positive nonmotile bacterium, is currently an emerging pathogen within rainbow trout (Oncorhynchus mykiss) farms in China, Brazil, the United States, and Japan. This study is the first to isolate, identify, and characterize W. ceti isolates from rainbow trout farmed in Mexico. In late 2015, a severe disease outbreak caused a 60% mortality rate among 20,000 fish. The diseased rainbow trout (100-300 g average) exhibited severe cachexia, body darkening, abdominal distension, exophthalmia, haemorrhages, and corneal opacity. Internally, diseased fish had pale gills; multifoca…

Different IgM+ B cell subpopulations residing within the peritoneal cavity of vaccinated rainbow trout are differently regulated by BAFF.

In teleost fish, IgM+ B cells are one of the main responders against inflammatory stimuli in the peritoneal cavity, as IgM+ B cells dominate the peritoneum after intraperitoneal stimulation, also increasing the levels of secreted IgM. BAFF, a cytokine known to play a major role in B cell biology, has been shown to be up-regulated along with its receptors in the peritoneum of rainbow trout upon antigenic exposure, however, the regulatory mechanisms underneath this response remain unclear. In this study, we have identified two different IgM+ B cell types residing in the peritoneal cavity of prev…

VP2 (PTA motif) encoding DNA vaccine confers protection against lethal challenge with infectious pancreatic necrosis virus (IPNV) in trout.

IPNV in Atlantic salmon is represented by various strains with different virulence and immunogenicity linked to various motifs of the VP2 capsid. IPNV variant with P217, T221, A247 (PTA) motif is found to be avirulent in Atlantic salmon, but virulent in rainbow trout, and other salmonid species. This study describes a DNA vaccine delivered intramuscularly encoding the VP2 protein of infectious pancreatic necrosis virus (IPNV) with PTA motif that confers high protection in rainbow trout (Oncorhynchus mykiss). Intramuscular injection of 2, 5 and 10 μg of DNA (pcDNA3.1-VP2) in rainbow trout fry (…

Intestinal ammonia transport in freshwater and seawater acclimated rainbow trout (Oncorhynchus mykiss): evidence for a Na+ coupled uptake mechanism.

In vitro gut sac experiments were performed on freshwater and 60% seawater acclimated trout (Oncorhynchus mykiss) under treatments designed to discern possible mechanisms of intestinal ammonia transport. Seawater acclimation increased ammonia flux rate into the serosal saline (Jsamm) in the anterior intestine, however it did not alter Jsamm in the mid- or posterior intestine suggesting similar mechanisms of ammonia handling in freshwater and seawater fish. Both fluid transport rate (FTR) and Jsamm were inhibited in response to basolateral ouabain treatment, suggesting a linkage of ammonia upta…

Molecular characterisation and infection dynamics of Dentitruncus truttae from trout (Salmo trutta and Oncorhynchus mykiss) in Krka River, Croatia.

Dentitruncus truttae (Acanthocephala, Palaeacanthocephala) is an intestinal parasite of fish that can cause extensive damage to the host digestive tract, yet little is known about its epidemiology and genetic variability. It is a member of the Illiosentidae family with a worldwide distribution restricted to parts of southeast Europe. Its usual host is brown trout (Salmo trutta), but we report here the first detection in the intestine of rainbow trout (Oncorhynchus mykiss). We examined the physiology of D. truttae-infected S. trutta and O. mykiss, seasonal and spatial variability of D. truttae …

Incidence of class 1 integron and other antibiotic resistance determinants in Aeromonas spp. from rainbow trout farms in Australia.

There is limited information on antibiotic resistance determinants present in bacteria of aquaculture origin in Australia. The presence of integron and other resistance determinants was investigated in 90 Aeromonas isolates derived from nine freshwater trout farms in Victoria (Australia). Polymerase chain reaction was carried out for the detection of integrase genes Int1, Int2 and Int3, gene cassette array, integron-associated aadA, sul1 and qac1 genes, streptomycin resistance genes strA-strB, β-lactamase resistance genes bla(TEM) and bla(SHV) , and tetracycline resistance genes tetA-E and tet…

Toxicity of single walled carbon nanotubes to rainbow trout, (Oncorhynchus mykiss): respiratory toxicity, organ pathologies, and other physiological effects.

Mammalian studies have raised concerns about the toxicity of carbon nanotubes (CNTs), but there is very limited data on ecotoxicity to aquatic life. We describe the first detailed report on the toxicity of single walled carbon nanotubes (SWCNT) to rainbow trout, using a body systems approach. Stock solutions of dispersed SWCNT were prepared using a combination of solvent (sodium dodecyl sulphate, SDS) and sonication. A semi-static test system was used to expose rainbow trout to either a freshwater control, solvent control, 0.1, 0.25 or 0.5 mgl(-1) SWCNT for up to 10 days. SWCNT exposure caused…

Regeneration of ultraviolet-sensitive cones in the retinal cone mosaic of thyroxin-challenged post-juvenile rainbow trout (Oncorhynchus mykiss).

Previous studies in our laboratory have examined the loss of ultraviolet-sensitive (UVS) cones and UV sensitivity. This study looks at the question of regeneration of UVS cones and its topographic distribution, along with several other measures of the cone mosaic. Topography of the cone mosaic in rainbow trout smolts (post-metamorphic juveniles) was examined under normal growth conditions and during an exogenous thyroid hormone (TH) challenge. Growth of trout retina was studied over six weeks. Retinas sampled at 0, 3 and 6 weeks were embedded in EPON resin, and thick (1 micro m) tangential sec…

Intracellular pH regulation and buffer capacity in CO2/HCO3-buffered media in cultured epithelial cells from rainbow trout gills.

The influence of a CO2/HCO3(-)-buffered medium on intracellular pH regulation of gill pavement cells from freshwater rainbow trout was examined in monolayers grown in primary culture on glass coverslips; intracellular pH (pHi) was monitored by continuous spectrofluorometric recording from cells loaded with 2',7'-bis(2-carboxyethyl)-5(6)-carboxy-fluoroscein. When cells in HEPES-buffered medium at normal pH = 7.70 were transferred to normal CO2/HCO3(-)-buffered medium ¿PCO2 = 3.71 mmHg, [HCO3-] = 6.1 mmol l(-1), extracellular pH (pHe) = 7.70¿, they exhibited a brief acidosis but subsequently reg…

Copper exposure impairs intra- and extracellular acid-base regulation during hypercapnia in the fresh water rainbow trout (Oncorhynchus mykiss).

In order to evaluate the impact of water-borne copper on acid-base regulation in fresh water rainbow trout, chronically cannulated fish were exposed to copper (0.6 mg 1(-1)), hypercapnia (water PCO2 of 6 mmHg) or a combination of copper and hypercapnia, while a fourth untreated group served as the control. Blood samples obtained at 0 h, 4 h and 24 h were analysed for acid-base status, ion concentrations and respiratory parameters. Tissue samples from caudal skeletal muscle, liver and gill filaments were examined for intracellular acid-base status, ion- and water contents, and copper concentrat…