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1.
Dis Aquat Organ ; 136(3): 227-234, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31724555

RESUMO

Chryseobacterium spp. (Family Flavobacteriaceae) are emergent fish pathogens in Europe, Asia and North America. In 2016-2017, 7 bacterial isolates were recovered from posterior kidney or spleen of cultured diseased rainbow trout Oncorhynchus mykiss (n = 1), green sturgeon Acipenser medirostris (n = 1), white sturgeon A. transmontanus (n = 2), blue ram cichlid Mikrogeophagus ramirezi (n = 1), and returning fall Chinook salmon O. tshawytscha (n = 2) from different freshwater systems. Bacterial colonies were visible after 24-48 h incubation at 20°C on agar media. Isolates were Gram-negative, rod-shaped, catalase and oxidase positive. Amplification and partial sequence analysis of the 16S rRNA and gyrB genes allocated the microorganisms to the genus Chryseobacterium sharing 97.2-99.6% similarity to 6 described Chryseobacterium spp. at the 16S rRNA locus, and 87.8-99.1% similarity at gyrB. Phylogenetic analyses in conjunction with percent sequence identity suggest some of the recovered isolates may represent novel Chryseobacterium subspecies or species. The pathogenicity of 5 isolates was evaluated experimentally in rainbow trout (n = 60), brown trout Salmo trutta (n = 60) and white sturgeon (n = 36) in flow-through freshwater at 18°C. Approximately 107 CFU fish-1 was injected in the epaxial musculature of anesthetized animals. Limited mortality was observed and no bacteria were recovered from dead or moribund fish post-challenge. Thirty days post-challenge, survivors were euthanized and multiple tissues were collected and fixed for histological analysis. No consistent histopathological changes were observed in challenged or control fish. While results suggest the recovered Chryseobacterium spp. may be opportunistic pathogens, further research is warranted to better understand the role of these bacteria in fish disease.


Assuntos
Chryseobacterium , Doenças dos Peixes , Oncorhynchus mykiss , Animais , California , Masculino , Filogenia , RNA Ribossômico 16S , Ovinos
2.
Sci Total Environ ; 693: 133295, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31635005

RESUMO

In this paper, we applied an individual-based model to study the population-level impacts of sub-lethal stressors affecting the metabolic pathways of three closely related trout species: Oncorhynchus mykiss (rainbow trout, RT), Salmo trutta (brown trout, BT) and Oncorhynchus calrki stomias (greenback cutthroat trout, GCT). Both RT and BT are well-studied species, and the former is widely used as a standard cold-water test species. These species are known to outcompete GCT, which is listed as threatened under the US Endangered Species Act. Our goal was to understand the extent to which stressor effects, which are often measured at the individual level, on taxonomically-related (i.e., surrogate) species can be informative of impacts on population dynamics in species that cannot be tested (e.g., listed species). When comparing stressor effects among species, we found that individual-level responses to each stressor were qualitatively comparable. Individual lengths and number of eggs decreased by similar percentages with respect to baseline, even if small quantitative differences were present depending on the physiological mode of action of the stressor. Individual-level effects in GCT were slightly greater when ingestion efficiency decreased, whereas effects in GCT and RT were greater when maintenance costs increased, and effects in BT were slightly greater when costs of growth increased. In contrast, results at the population level differed markedly among species with GCT the most impacted by sub-lethal stress effects on individual metabolism. Our findings suggest that using non-listed species to assess the risks of stressors to listed species populations may be misleading, even if the species are closely related and show similar individual-level responses. Mechanistic population models that incorporate species life history and ecology can improve inter-species extrapolation of stressor effects.


Assuntos
Oncorhynchus mykiss , Animais , Dinâmica Populacional , Alimentos Marinhos , Estresse Fisiológico
3.
Aquat Toxicol ; 215: 105282, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31509759

RESUMO

Aquatic ecosystems are now chronically polluted by a cocktail of many chemical substances. There is now clear evidence of associations between exposure to pollutants and greater susceptibility to pathogens. The aim of the present study was to characterize the defense capacities of rainbow trout (Oncorhynchus mykiss), chronically exposed to pendimethalin (PD), to subsequent experimental challenge with the infectious hematopoietic necrosis virus (IHNV). Immunological responses were examined at different organizational levels, from individuals to gene expression. No negative effects of PD were noted on the Fulton index nor on the liver or spleen somatic indices (LSI; SSI) before viral infection, but the infectious stress seems to generate a weak but significant decrease in Fulton and LSI values, which could be associated with consumption of energy reserves. During the viral challenges, the distribution of cumulative mortality was slightly different between infected groups. The impact of the virus on fish previously contaminated by PD started earlier and lasted longer than controls. The proportion of seropositive fish was lower in the fish group exposed to PD than in the control group, with similar quantities of anti-IHNV antibodies secreted in positive fish, regardless of the treatment. While no significant differences in C3-1 expression levels were detected throughout the experiment, TNF1&2, TLR3, Il-1ß and IFN expression levels were increased in all infected fish, but the difference was more significant in fish groups previously exposed to herbicide. On the other hand, ß-def expression was decreased in the pendimethalin-IHNV group compared to that in fish only infected by the virus (control-IHNV group).


Assuntos
Herbicidas/toxicidade , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Vírus da Necrose Hematopoética Infecciosa/fisiologia , Oncorhynchus mykiss/genética , Oncorhynchus mykiss/imunologia , Infecções por Rhabdoviridae/imunologia , Infecções por Rhabdoviridae/veterinária , Compostos de Anilina/toxicidade , Animais , Doenças dos Peixes/genética , Doenças dos Peixes/imunologia , Doenças dos Peixes/virologia , Regulação da Expressão Gênica/efeitos dos fármacos , Oncorhynchus mykiss/virologia , Infecções por Rhabdoviridae/genética , Infecções por Rhabdoviridae/patologia , Poluentes Químicos da Água/toxicidade
4.
Environ Sci Technol ; 53(20): 12062-12070, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31553583

RESUMO

We studied the role of the fish intestine as a barrier for organic chemicals using the epithelial barrier model built on the rainbow trout (Oncorhynchus mykiss) intestinal cell line, RTgutGC and the newly developed exposure chamber, TransFEr, specifically designed to work with hydrophobic and volatile chemicals. Testing 11 chemicals with a range of physicochemical properties (logKOW: 2.2 to 6.3, logHLC: 6.1 to 2.3) and combining the data with a mechanistic kinetic model enabled the determination of dominant processes underlying the transfer experiments and the derivation of robust transfer rates. Against the current assumption in chemical uptake modeling, chemical transfer did not strictly depend on the logKOW but resulted from chemical-specific intracellular accumulation and biotransformation combined with paracellular and active transport. Modeling also identified that conducting elaborate measurements of the plastic parts, including the polystyrene insert and the PET filter, is unnecessary and that stirring in the TransFEr chamber reduced the stagnant water layers compared to theoretical predictions. Aside from providing insights into chemical uptake via the intestinal epithelium, this system can easily be transferred to other cell-based barrier systems, such as the fish gill or mammalian intestinal models and may improve in vitro-in vivo extrapolation and prediction of chemical bioaccumulation into organisms.


Assuntos
Oncorhynchus mykiss , Poluentes Químicos da Água , Animais , Biotransformação , Brânquias , Intestinos , Compostos Orgânicos
5.
Sci Total Environ ; 691: 1297-1309, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31466209

RESUMO

Per- and poly-fluorinated substances (PFAS) are widely found in freshwater ecosystems because of their resistance to degradation. Among them, several long-chain perfluoroalkyl acids bioaccumulate in aquatic vertebrates, but our understanding of the mechanisms of absorption, distribution and elimination is still limited in fish. For this purpose, we developed a 10-compartment physiologically-based toxicokinetic (PBTK) model to elucidate perfluorooctane sulfonate (PFOS) kinetics in adult rainbow trout. This PBTK model included various physiological characteristics: blood perfusion to each organ, plasmatic fraction, PFOS free fraction, and growth of individuals. The parameters were optimized using Bayesian inferences. First, only PFOS absorption by diet was considered in the model as well as its elimination by urine, bile and feces. Then two mechanistic hypotheses, assumed to govern PFOS toxicokinetics in fish, namely the enterohepatic cycle and the absorption and elimination though gills, were tested. Improvement of the model's fit to the data was studied in each organ by comparing predictions with observed data using relative error. The experimental data set was obtained from an exposure experiment, where adult rainbow trout were fed with a PFOS-spiked diet for 42 days, followed by a 35-day depuration period. In all cases, PFOS concentrations were accurately predicted in organs and feces by the model. The results of this PBTK model demonstrated that feces represented the major elimination route for PFOS while urine was a minor route. Also, PFOS branchial uptake can be substantial despite low concentrations of the compound in water, and elimination through gills should not be neglected. Finally, the enterohepatic cycle is likely to play a minor role in PFOS toxicokinetics. Overall, this PBTK model accurately described PFOS distribution in rainbow trout and provides information on the relative contribution of absorption and elimination pathways.


Assuntos
Fluorcarbonetos/metabolismo , Oncorhynchus mykiss/metabolismo , Poluentes Químicos da Água/metabolismo , Alcanossulfonatos/metabolismo , Ácidos Alcanossulfônicos/metabolismo , Animais , Caprilatos/metabolismo , Toxicocinética
6.
Aquat Toxicol ; 215: 105283, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31470336

RESUMO

Recent studies have demonstrated that white sturgeon are more sensitive to acute exposure to Cu than rainbow trout (Oncorhynchus mykiss), especially during early life-stages. However, the physiological mechanisms underlying this difference in sensitivity to Cu is not known. In the present study, we first confirmed the higher sensitivity (lower 96 h LC50 values) of white sturgeon to Cu at three different life stages (larva, swim-up, and juvenile) relative to their counterparts in rainbow trout. We also demonstrated that acute exposure to Cu (50 µg/L for 4.5 h) caused a significantly greater reduction in the rate of waterborne Na uptake in white sturgeon relative to that in rainbow trout across all three life-stages. In agreement with this observation, we also found that acute exposure to Cu (20 µg/L for 48 h) elicits a significantly greater decrease in whole body Na level in all life stages of white sturgeon compared to rainbow trout. In contrast, white sturgeon demonstrated a higher or similar level of Cu body burden relative to rainbow trout during acute Cu exposure (20 µg/L for 24 h), thereby indicating that Cu bioaccumulation is not a good indicator of its toxicity in these species. Overall, our study demonstrated that the differences in sensitivity to acute Cu exposure between white sturgeon and rainbow trout can be explained on the basis of differential effects of Cu on Na homeostasis.


Assuntos
Cobre/toxicidade , Peixes/fisiologia , Homeostase/efeitos dos fármacos , Oncorhynchus mykiss/fisiologia , Sódio/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Exposição Ambiental , Dose Letal Mediana , Oncorhynchus mykiss/sangue , ATPases Translocadoras de Prótons/metabolismo , Sódio/sangue , ATPase Trocadora de Sódio-Potássio/metabolismo , Testes de Toxicidade Aguda , Qualidade da Água
7.
Aquat Toxicol ; 214: 105264, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31377504

RESUMO

A by-product of mitochondrial substrate oxidation and electron transfer to generate cellular energy (ATP) is reactive oxygen species (ROS). Superoxide anion radical and hydrogen peroxide (H2O2) are the proximal ROS produced by the mitochondria. Because low levels of ROS serve critical regulatory roles in cell physiology while excessive levels or inappropriately localized ROS result in aberrant physiological states, mitochondrial ROS need to be tightly regulated. While it is known that regulation of mitochondrial ROS involves balancing the rates of production and removal, the effects of stressors on these processes remain largely unknown. To illuminate how stressors modulate mitochondrial ROS homeostasis, we investigated the effects of temperature and cadmium (Cd) on H2O2 emission and consumption in rainbow trout liver mitochondria. We show that H2O2 emission rates increase with temperature and Cd exposure. Energizing mitochondria with malate-glutamate or succinate increased the rate of H2O2 emission; however, Cd exposure imposed different patterns of H2O2 emission depending on the concentration and substrate. Specifically, mitochondria respiring on malate-glutamate exhibited a saturable graded concentration-response curve that plateaued at 5 µM while mitochondria respiring on succinate had a biphasic concentration-response curve characterized by a spike in the emission rate at 1 µM Cd followed by gradual diminution at higher Cd concentrations. To explain the observed substrate- and concentration-dependent effects of Cd, we sequestered specific mitochondrial ROS-emitting sites using blockers of electron transfer and then tested the effect of the metal. The results indicate that the biphasic H2O2 emission response imposed by succinate is due to site IIF but is further modified at sites IQ and IIIQo. Moreover, the saturable graded H2O2 emission response in mitochondria energized with malate-glutamate is consistent with effect of Cd on site IF. Additionally, Cd and temperature acted cooperatively to increase mitochondrial H2O2 emission suggesting that increased toxicity of Cd at high temperature may be due to increased oxidative insult. Surprisingly, despite their clear stimulatory effect on H2O2 emission, Cd, temperature and bioenergetic status did not affect the kinetics of mitochondrial H2O2 consumption; the rate constants and half-lives for all the conditions tested were similar. Overall, our study indicates that the production processes of rainbow trout liver mitochondrial H2O2 metabolism are highly responsive to stressors and bioenergetics while the consumption processes are recalcitrant. The latter denotes the presence of a robust H2O2 scavenging system in liver mitochondria that would maintain H2O2 homeostasis in the face of increased production and reduced scavenging capacity.


Assuntos
Cádmio/toxicidade , Metabolismo Energético , Mitocôndrias Hepáticas/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Temperatura Ambiente , Animais , Respiração Celular/efeitos dos fármacos , Transporte de Elétrons , Feminino , Peróxido de Hidrogênio/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias Hepáticas/efeitos dos fármacos , NAD/metabolismo , Oncorhynchus mykiss/fisiologia , Poluentes Químicos da Água/toxicidade
8.
Genet Sel Evol ; 51(1): 42, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31387519

RESUMO

BACKGROUND: Columnaris disease (CD) is an emerging problem for the rainbow trout aquaculture industry in the US. The objectives of this study were to: (1) identify common genomic regions that explain a large proportion of the additive genetic variance for resistance to CD in two rainbow trout (Oncorhynchus mykiss) populations; and (2) estimate the gains in prediction accuracy when genomic information is used to evaluate the genetic potential of survival to columnaris infection in each population. METHODS: Two aquaculture populations were investigated: the National Center for Cool and Cold Water Aquaculture (NCCCWA) odd-year line and the Troutlodge, Inc., May odd-year (TLUM) nucleus breeding population. Fish that survived to 21 days post-immersion challenge were recorded as resistant. Single nucleotide polymorphism (SNP) genotypes were available for 1185 and 1137 fish from NCCCWA and TLUM, respectively. SNP effects and variances were estimated using the weighted single-step genomic best linear unbiased prediction (BLUP) for genome-wide association. Genomic regions that explained more than 1% of the additive genetic variance were considered to be associated with resistance to CD. Predictive ability was calculated in a fivefold cross-validation scheme and using a linear regression method. RESULTS: Validation on adjusted phenotypes provided a prediction accuracy close to zero, due to the binary nature of the trait. Using breeding values computed from the complete data as benchmark improved prediction accuracy of genomic models by about 40% compared to the pedigree-based BLUP. Fourteen windows located on six chromosomes were associated with resistance to CD in the NCCCWA population, of which two windows on chromosome Omy 17 jointly explained more than 10% of the additive genetic variance. Twenty-six windows located on 13 chromosomes were associated with resistance to CD in the TLUM population. Only four associated genomic regions overlapped with quantitative trait loci (QTL) between both populations. CONCLUSIONS: Our results suggest that genome-wide selection for resistance to CD in rainbow trout has greater potential than selection for a few target genomic regions that were found to be associated to resistance to CD due to the polygenic architecture of this trait, and because the QTL associated with resistance to CD are not sufficiently informative for selection decisions across populations.


Assuntos
Cruzamento , Mapeamento Cromossômico , Doenças dos Peixes/genética , Infecções por Flavobacteriaceae/veterinária , Flavobacterium , Oncorhynchus mykiss/genética , Animais , Resistência à Doença/genética , Feminino , Pesqueiros , Infecções por Flavobacteriaceae/genética , Padrões de Herança , Masculino , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Seleção Genética
9.
Med Lav ; 110(3): 202-214, 2019 06 28.
Artigo em Italiano | MEDLINE | ID: mdl-31268427

RESUMO

INTRODUCTION: Cement-based material containing asbestos was found in the water of a pond in the city of Milan, Italy, where recreational fishing activities take place. Some fishes are in 'no-kill' fishing areas, others are caught and consumed. OBJECTIVE: To verify the presence of asbestos in water, sediments and some fish species living in the pond. To verify the presence of asbestos in fish feed and to test fish exposure by ingestion. METHODS: Samples of water, sediments, fish feed and fish species have been collected and the presence of asbestos fibers has been ascertained in the different matrices. RESULTS: No traces of asbestos were found in water. Instead, the asbestos content in sediments was beyond regulatory limits. Asbestos was detected also in benthic fish species, and in rainbow trout (Oncorhynchus mykiss) that does not reproduce in the pond but must be restocked periodically through aquaculture. In the meat of the grass carp (Ctenopharyngodon idella) 36,000,000 fibers/100 g of wet cloth have been found. Values up to 15,000,000 ff/100 g of wet cloth have been detected in the rainbow trout. Asbestos has also been found in animal feeds, in particular crocidolite fibers and asbestos tremolite bundles. CONCLUSIONS: Benthic fish species have likely been contaminated by their close contact with the polluted bottom of the pond. Instead, the presence of asbestos in the trout is probably linked to a previous contamination during farming, since this fish spend a brief period of time in the water of the pond. Asbestos distribution and concentration exclude a risk for public health; however, some values of asbestos found in fish meat deserve attention. Accordingly, precautionary indications have been given to the Municipality of Milan and to the fishermen association. A larger scale monitoring of water, food and animal feed is worth performing to better assess exposure by ingestion.


Assuntos
Aquicultura , Asbestos , Carpas , Oncorhynchus mykiss , Animais , Asbestos/análise , Itália , Tanques
10.
Ecotoxicol Environ Saf ; 182: 109385, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31260918

RESUMO

The present study was the first approach conducted under environmental concentrations of Gd-DOTA and Gd-DTPA-BMA to assess cellular impacts of these compounds. Gd-DOTA (Gadoteric acid) is one of the most stable contrast agent, currently used as Dotarem® formulation during Magnetic Resonance Imaging exams. The study was mainly performed on a Zebra Fish cell line (ZF4; ATCC CRL-2050). At the concentrations of 0.127 nM and 63.59 nM (respectively 20 ng and 10 µg of Gd/L), we did not observed any toxicity of Dotarem® but a slowdown of the cell growth was clearly measured. The effect is independent of medium renewing during 6 days of cell culturing. The same effect was observed i-with Gd-DOTA on another fish cell line (RT W1 gills; ATCC CRL-2523) and ii-with another contrast agent (Gd-DTPA-BMA - Omniscan®) on ZF4 cells. On the ZF4 cell line, the diminution of the cell growth was of the same order during 20 days of exposure to a culture medium spiked with 63.59 nM of Dotarem® and was reversible within the following 8 days when Dotarem® was removed from the medium. As shown by using modified DOTA structure (Zn-DOTA), the effect may be due to the chelating structure of the contrast agent rather than to the Gd ion. Until now, the main attention concerning the impact of Gd-CA on living cells concerned the hazard due to Gd release. According to our results, quantifying the presence of Gd-CA chelating structures in aquatic environments must be also monitored.


Assuntos
Meios de Contraste/toxicidade , Gadolínio DTPA/toxicidade , Compostos Heterocíclicos/toxicidade , Meglumina/toxicidade , Compostos Organometálicos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/análise , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Quelantes , Imagem por Ressonância Magnética , Oncorhynchus mykiss , Peixe-Zebra
11.
Environ Pollut ; 252(Pt B): 1448-1454, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31265955

RESUMO

The Keban Reservoir, which is the second man-made waterbody in Turkey, has the biggest rainbow trout production in the country. In this study, the impacts of rainbow trout farms on water and sediment chemistry were investigated. Water and sediment samples were taken at distances of 0, 10, 25, 50 and 100 m from the edge of the cages at the three fish farms, and at the respective reference stations. Samples were also taken at 0 m stations and reference stations in the late August when there were no fish in the cages. Physico-chemical variables and trace metals were analysed in all samples. Due to likely high dilution rates and recycling processes in the water column of the reservoir, little changes in the water quality parameters associated with wastes of the fish farms were noticed. When compared with those in the sediment samples at the stations near the edge of cages, the lower concentrations of total phosphorus (TP), total nitrogen (TN), organic matter (OM), total carbon (TC), sulfide (S2-), arsenic (As), cobalt (Co), copper (Cu), manganese (Mn) and zinc (Zn), and higher values of redox potential (Eh) were found at the reference stations. According to organic enrichment classification based on S2- and Eh values, sediments of the three fish farms in the period when there were fish in the cages fell into the oxic category, whereas sediments in the August (no fish farming activity) fell into the normal category. Also, it was found in the August that most of sediment quality parameters at the 0 m stations had close values to those at the reference stations. These results revealed that a three-month period when there were no fish in the cages allows for sediments to return to reference station conditions.


Assuntos
Monitoramento Ambiental/métodos , Pesqueiros , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise , Água/química , Animais , Arsênico/análise , Carbono/análise , Cobre/análise , Fazendas , Peixes , Nitrogênio/análise , Oncorhynchus mykiss , Fósforo/análise , Alimentos Marinhos/análise , Oligoelementos/análise , Turquia , Qualidade da Água , Zinco/análise
12.
Bull Environ Contam Toxicol ; 103(3): 391-399, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31338521

RESUMO

The aim of the study was to investigate acute (96-h LC50) toxicity of the complex metal (Zn, Pb, Cd, Cu, Ni and Cr) mixture (MIX) to European perch (Perca fluviatilis) and rainbow trout (Oncorhynchus mykiss), and to examine differences between locomotor and respiratory endpoints based on rapidness and sensitivity of fish responses to short-term (2 h) metal mixture exposure. MIX was prepared taking into consideration the maximum-permissible-concentrations (MPC) set for these metals in EU inland waters (Directive 2008/105/EC). The studied behavioral and respiratory responses of O. mykiss, in contrast to those of P. fluviatilis, were found to be significantly affected by the relationship between exposure duration and treatment. In O. mykiss, gill ventilation frequency (GVF) was found to be the most rapid and sensitive endpoint of all the investigated ones. However, the investigated behavioral and respiratory endpoints of P. fluviatilis showed its behavioral insensitivity to MIX exposure.


Assuntos
Comportamento Animal/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Metais/toxicidade , Oncorhynchus mykiss/fisiologia , Percas/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Respiração
13.
Aquat Toxicol ; 214: 105259, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31352075

RESUMO

The potential of using gene expression signature as a biomarker of toxicants exposure was explored in the microalga Chlamydomonas reinhardtii exposed 2 h to mercury (Hg) as inorganic mercury (IHg) and methyl mercury (MeHg) in presence of copper (Cu) and Suwannee River Humic Acid (SRHA). Total cellular Hg (THg = IHg + MeHg) decreased in presence of SRHA for 0.7 nM IHg and 0.4 nM MeHg, but increased for 70 nM IHg exposure. In mixtures of IHg + MeHg and (IHg or MeHg) + Cu, SRHA decreased THg uptake, except for 0.7 nM IHg + 0.4 nM MeHg which was unchanged (p-value>0.05). In the absence of SRHA, 0.5 µM Cu strongly decreased intracellular THg concentration for 70 nM IHg, while it had no effect for 0.7 nM IHg and 0.4 nM MeHg. The expression of single transcripts was not correlated with measured THg uptake, but a subset of 60 transcripts showed signatures specific to the exposed metal(s) and was congruent with exposure concentration. Notably, the range of fold change values of this subset correlated with THg bioaccumulation with a two-slope pattern in line with [THg]intra/[THg]med ratios. Gene expression signature seems a promising approach to complement chemical analyses to assess bioavailability of toxicants in presence of other metals and organic matter.


Assuntos
Chlamydomonas reinhardtii/genética , Exposição Ambiental , Perfilação da Expressão Gênica , Mercúrio/toxicidade , Compostos de Metilmercúrio/toxicidade , Animais , Disponibilidade Biológica , Cádmio/toxicidade , Chlamydomonas reinhardtii/efeitos dos fármacos , Chlamydomonas reinhardtii/metabolismo , Feminino , Substâncias Húmicas/análise , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , NAD/metabolismo , Oncorhynchus mykiss/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Temperatura Ambiente , Poluentes Químicos da Água/toxicidade
14.
Fish Shellfish Immunol ; 92: 621-628, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31260736

RESUMO

Intestine in fish is a complex multifunctional organ, not only plays roles in digestion and absorption of nutrient, but also has critical role in immunity. The present study evaluated the effects of different levels of dietary sodium butyrate [Butirex® C4 (Butirex)] on intestinal immune-,antioxidant-and tight junction-related gene expression injuvenile rainbow trout(Oncorhynchusmykiss). 240 healthy rainbow trout were dispensed in 12 fiberglass tanks appointed to four treatments [0 (control), 1.5 (B1.5), 2.5 (B2.5) and 5 (B5)g Butirex per kg diet]. After a 45-day feeding trial, the fish fed with the Butirex-supplemented diets showed higher intestinal lysozyme (LYZ), complement(ACH50) and bactericidal activities; the elevations in ACH50 and bactericidal activities depended on Butirex levels (P < 0.05). The Butirex-supplemented groups, particularly the B2.5 group, had significantly higher LYZ gene expression compared to the control group (P < 0.05). Butirex at 2.5 and 5 g/kg levels led to significantly higher IL-1ß gene expression. B2.5 and B5 had significantly lower and higher TNF-α gene expression compared to the control group (P < 0.05). The B2.5 group had significantly higher TGF-B, and significantly lower IL-8 compared to the control group (P < 0.05). The B1.5 and B2.5 group had significantly higher IL-10 gene expression compared to the control group (P < 0.05). The B2.5 and B5 groups had significantly higher SOD gene expression compared to the other groups; the highest expression was related to the B2.5 group (P < 0.05). Dietary Butirex supplementation significantly up-regulated CAT and GPx genes expression compared to the control group; the highest expression as related to the B2.5 and B5 groups (P < 0.05). The B2.5 group had significantly lower CLD12 gene expression compared to the control group (P < 0.05). The B2.5 and B5 groups had significantly higher CLD3, OCLD and ZO-1 gene expression compared to the control. The highest CLD3, ZO-1 gene expressions was related to the B2.5, and B5 groups respectively (P < 0.05). After challenge with Streptococcus iniae, B2.5 and B5 had significantly higher survival compared to the control group (55.6 ±â€¯7.70 and 68.9 ±â€¯10.2 vs. 33.3 ±â€¯6.67). In conclusion, Butirex is efficient immune stimulant and health booster in rainbow trout, which augments the fish resistance to disease. Modulation of immune components, cytokines, antioxidant system and intestinal integrity might involve in improving disease resistance in Butirex-treated fish. Although most of the examined genes were modulated by 2.5 g/kg Butirex under normal conditions, 5 g/kg level is recommended under pathogenic state to mitigate mortality.


Assuntos
Ácido Butírico/metabolismo , Resistência à Doença/efeitos dos fármacos , Doenças dos Peixes/imunologia , Imunidade Inata/efeitos dos fármacos , Oncorhynchus mykiss/imunologia , Transcriptoma/efeitos dos fármacos , Ração Animal/análise , Animais , Antioxidantes/metabolismo , Ácido Butírico/administração & dosagem , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Proteínas de Peixes/metabolismo , Intestinos/efeitos dos fármacos , Oncorhynchus mykiss/metabolismo , Distribuição Aleatória , Sódio na Dieta/administração & dosagem , Infecções Estreptocócicas/imunologia , Streptococcus iniae/fisiologia , Proteínas de Junções Íntimas/metabolismo , Transcriptoma/imunologia
15.
Fish Shellfish Immunol ; 92: 736-745, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31284045

RESUMO

Viral diseases in aquaculture were challenging because there are few preventative measures and/or treatments. Our previous study indicated that imidazole arctigenin derivatives possessed antiviral activities against infectious hematopoietic necrosis virus (IHNV). Based on the structure-activity relationship in that study, a new imidazole arctigenin derivative, 4-(8-(2-ethylimidazole)octyloxy)-arctigenin (EOA), was designed, synthesized and its anti-IHNV activity was evaluated. By comparing inhibitory concentration at half-maximal activity (IC50), we found that EOA (IC50 = 0.56 mg/L) possessed a higher antiviral activity than those imidazole arctigenin derivatives in our previous study. Besides, EOA could significantly decrease cytopathic effect (CPE) and viral titer induced by IHNV in epithelioma papulosum cyprinid (EPC) cells. In addition, EOA significantly inhibited apoptosis induced by IHNV in EPC cells. Further data verified that EOA inhibited IHNV replication in rainbow trout, with reducing 32.0% mortality of IHNV-infected fish. The results suggested that EOA was more stable with a prolonged inhibitory half-life in the early stage of virus infection (1-4 days). Consistent with above results, EOA repressed IHNV glycoprotein gene expression in virus sensitive tissues (kidney and spleen) in the early stage of virus infection. Moreover, histopathological evaluation showed that tissues from the spleen and kidney of fish infected with IHNV exhibited pathological changes. But there were no lesions in any of the tissues from the control group and EOA-treaten group. In accordance with the histopathological assay, EOA could elicited anti-inflammation response in non-viral infected rainbow trout by down-regulating the expression of cytokine genes (IL-8, IL-12p40, and TNF-α). Altogether, EOA was expected to be a therapeutic agent against IHNV infection in the field of aquaculture.


Assuntos
Antivirais/farmacologia , Doenças dos Peixes/prevenção & controle , Furanos/farmacologia , Vírus da Necrose Hematopoética Infecciosa/efeitos dos fármacos , Lignanas/farmacologia , Oncorhynchus mykiss , Animais , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos/veterinária , Doenças dos Peixes/virologia , Testes de Sensibilidade Microbiana/veterinária , Infecções por Rhabdoviridae/prevenção & controle , Infecções por Rhabdoviridae/veterinária , Infecções por Rhabdoviridae/virologia
16.
Chemosphere ; 235: 952-958, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31299708

RESUMO

Ecological risk of chemicals to aquatic-phase amphibians has historically been evaluated by comparing estimated environmental concentrations in surface water to surrogate toxicity data from fish species. Despite their obvious similarities, there are biological disparities among fish and amphibians that could affect their exposure and response to chemicals. Given the alarming decline in amphibians, in which anthropogenic pollutants play at least some role, investigating the risk of chemicals to amphibians is becoming increasingly important. Here, we evaluate relative sensitivity of fish and larval aquatic-phase amphibians to 45 different pesticides using existing data from three standardized toxicity test designs: (1) amphibian metamorphosis assay (AMA) with the African clawed frog (Xenopus laevis); (2) fish short-term reproduction assay (FSTRA) with the fathead minnow (Pimephales promelas); (3) fish early life stage test (ELS) with fathead minnows or rainbow trout (Oncorhynchus mykiss). The advantage of this dataset over previous work is that the underlying studies are consistent in exposure method, study duration, test species, endpoints measured, and number of concentrations tested. We found very strong positive relationships between fish and frog lowest adverse effect concentrations (LOAEC) for survival [Spearman's rank correlation (rs) = 0.88], body weight (rs = 0.86), and length (rs = 0.89) with only one out of 45 chemicals (propiconazole) exhibiting 100-folder greater sensitivity in frogs relative to fish. While our results suggest comparable toxicity for pesticides between fish and aquatic-phase amphibians under these test conditions, further research with a greater diversity of amphibians and exposure scenarios will help determine the relevance of these results across species and life stages.


Assuntos
Cyprinidae/embriologia , Metamorfose Biológica/efeitos dos fármacos , Oncorhynchus mykiss/embriologia , Praguicidas/toxicidade , Poluentes Químicos da Água/toxicidade , Xenopus laevis/embriologia , Animais , Ecologia , Larva/efeitos dos fármacos , Reprodução , Medição de Risco/métodos , Alimentos Marinhos
17.
Vet Immunol Immunopathol ; 213: 109885, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31307670

RESUMO

Protec™ is a commercial aquafeed (Skretting Italia) containing a combination of glucans, vitamin C, vitamin E and zinc (immune support pack). No research information concerning its capability to improve fish immune response is available, so in this study the potential immunomodulatory effects of Protec™ were investigated in rainbow trout (Oncorhynchus mykiss). Head kidney (HK) leukocytes from adult fish (100 g, n = 6) were in vitro incubated with Protec™ immune support pack resulting in significantly higher respiratory burst activity and proliferation. Specifically, sonicated Protec™ immune support pack (160 µg/ml) induced a respiratory burst response similar to that promoted by zymosan and lipopolysaccharide (LPS), while non-sonicated Protec™ immune support pack induced a response comparable to that of cells stimulated with phorbol myristate acetate (PMA). Moreover, the proliferation of leukocytes exposed to sonicated Protec™ immune support pack (20 µg/ml) was significantly higher than that of cells stimulated with zymosan, and it was comparable to the proliferation of cells stimulated with phytohaemagglutinin (PHA) and LPS. Afterwards, a feeding trial was performed in a rainbow trout farm. Two groups of juvenile rainbow trout (10 g) were acclimated for 7 weeks before the experiment and fed daily with a commercial control diet (Optiline HE, Skretting Italia) at 2% BW/day. At the end of acclimation, one group of fish was fed with Protec™ diet (Skretting Italia) at 2% BW/day whereas the other group continued to feed the control diet at the same level for further 4 weeks. Then, fish were sampled (HK leukocytes from n = 6 fish/group, serum from n = 12 fish/group) or intraperitoneally vaccinated against lactococcosis (n = 160/dietary group/time point). Fish fed the same diets for further 4 weeks after vaccination, then feeding returned to the control diet in both groups until the end of the trial. The specific antibody response was recorded at 4 and 8 weeks after vaccination (n = 12 fish/group). The administration of Protec™ significantly enhanced the respiratory burst activity of leukocytes and the synthesis of specific IgM against Lactococcus garvieae, whereas the serum lysozyme activity was unaffected. The present research suggests that the administration of Protec™ can improve both innate and adaptive immune response of rainbow trout, proving to be an interesting strategy for enhancing the immune reactivity of fish to vaccines.


Assuntos
Ração Animal , Anticorpos Antibacterianos/sangue , Infecções por Bactérias Gram-Positivas/veterinária , Imunidade Inata , Lactococcus , Oncorhynchus mykiss/imunologia , Imunidade Adaptativa , Adjuvantes Imunológicos/administração & dosagem , Animais , Proliferação de Células , Dieta/veterinária , Feminino , Doenças dos Peixes/imunologia , Infecções por Bactérias Gram-Positivas/imunologia , Imunoglobulina M/sangue , Leucócitos/imunologia , Oncorhynchus mykiss/microbiologia , Explosão Respiratória
18.
Ecotoxicol Environ Saf ; 182: 109311, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31272021

RESUMO

Effects of sub-lethal concentrations (0 (control), 0.009, 0.014, and 0.023 ppm) of the organophosphate insecticide "malathion" to rainbow trout (Oncorhynchus mykiss) after the determination of LC50-96 h value (0.093 ppm) were evaluated. Changes in biomarkers of neurotoxicity (acetylcholinesterase (AChE) activity), genotoxicity (DNA damage), and hematological parameters (red (RBC) and white (WBC) blood cell count, hemoglobin (Hb), hematocrit (Hct), mean cell hemoglobin (MCH), mean cell volume (MCV), and mean cell hemoglobin concentration (MCHC)) were assessed for a 15-day exposure. A significant time- and dose-dependent reduction in AChE activities of gill, muscle, brain, and liver tissues was found. However, the AChE activity was less affected by malathion concentration than by exposure time. DNA damage of erythrocytes at different malathion concentrations increased by increasing the experimental time up to the fourth day. A decrease in the count of WBC, RBC, and Hct and an increase in the number of MCH and MCV were observed by increasing malathion exposure dose and time (p < 0.05). An increase in the malathion concentration and exposure time significantly resulted in a decrease in Hb and an increase in MCHC. A significant improvement in AChE activity; DNA damage; and RBC, Hb, Hct, MCV, and MCH indices was detected during a 30-day recovery period, but the WBC count changed insignificantly. The recovery pattern based on 100% water exchange with clean water could be a successful strategy to improve the biomarker responses of rainbow trout habituating in contaminated aquatic environments.


Assuntos
Acetilcolinesterase/metabolismo , Malation/toxicidade , Oncorhynchus mykiss/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Dano ao DNA , Índices de Eritrócitos , Eritrócitos/efeitos dos fármacos , Hematócrito , Hemoglobinas/análise , Dose Letal Mediana , Contagem de Leucócitos
19.
Toxicol Lett ; 313: 101-107, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31254606

RESUMO

Fumonisins are common contaminants of maize. The neutral red assay, using the RTL-W1 trout liver cell line, and the fish embryo test (FET), using zebrafish, were selected to assess the effect of pH on the cytotoxicity, acute toxicity and teratogenicity of fumonisin B1 (FB1). The results demonstrated that FB1 exerts low cytotoxicity towards RTL-W1 cells without pH adjustment (IC50 1 746 µM), and no cytotoxicity after pH-adjustment to physiological conditions. The LC50 value for FB1 in the FET (1 058 µM at 48 h) confirmed low acute toxicity. Adjusting the pH to physiological conditions reduced the acute toxicity of FB1 towards zebrafish embryos, emphasising the importance of acidity/basicity of the medium in toxicity testing. Hydrolysed FB1 was less toxic than FB1 (LC50 2 690 µM at 48 h), and neither were teratogenic towards zebrafish embryos. Results confirm that the FET may account for effects not observable in cell cultures.


Assuntos
Embrião não Mamífero/efeitos dos fármacos , Fumonisinas/toxicidade , Fígado/efeitos dos fármacos , Oncorhynchus mykiss , Peixe-Zebra/embriologia , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Concentração de Íons de Hidrogênio , Hidrólise , Concentração Inibidora 50 , Dose Letal Mediana , Fígado/patologia , Medição de Risco
20.
Sci Total Environ ; 687: 24-33, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31202010

RESUMO

The toxic effects produced by the co-exposure to low- and non-toxic concentrations of zinc oxide (ZnONPs) and copper nanoparticles (CuNPs) was assessed in rainbow trout following the OECD Test Guideline 203. Four groups of trouts were exposed for 96 h to a range of concentrations (0.0425-0.34 mg/L) of CuNPs (50 nm) in combination with a fixed non-toxic concentration (1.25 mg/L) of ZnONPs (25 nm) determined from an independent concentration-response study. One additional group was exposed to the highest concentration of CuNPs alone. Behaviour and mortality were observed during the experiment. After 96 h exposure, accumulated levels of Cu and Zn in the fish were measured by ICP-MS and ICP-OES, respectively. The induction of oxidative stress in liver and gills was evaluated by the glutathione-S-transferase (GST) activity and the reduced glutathione (GSH) / oxidized glutathione (GSSG) ratio. The ethoxyresorufin-O-deethylase (EROD) activity was also assessed. The results showed that CuNPs at the highest tested concentration do not cause acute toxicity, whereas exposure to all mixtures caused mortality, which was inversely proportional to the concentration of CuNPs (from 28% to 86% survival). Accumulated levels of Cu and Zn in the fish increased with the increasing concentrations of CuNPs, suggesting that the presence of CuNPs favours the entry of Zn. In general, the GST activity increased significantly in the gills of co-exposed groups, whereas the GSH/GSSG ratio was altered in the liver. The EROD activity was not modified. In conclusion, the co-exposure to these NPs potentiates their toxicity, observing an alteration of the GST activity and GSH/GSSG ratio in gill and liver, which was more pronounced at the lowest concentration of CuNPs. The lower toxic effect observed with the highest concentrations of CuNPs coincides with a greater internalization of Zn.


Assuntos
Cobre/toxicidade , Nanopartículas Metálicas/toxicidade , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/toxicidade , Animais , Oncorhynchus mykiss , Testes de Toxicidade Aguda
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