CNRS Environmental Stress and Aquatic Monitoring

Reims, France

CNRS Environmental Stress and Aquatic Monitoring

Reims, France
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Seemann F.,City University of Hong Kong | Knigge T.,CNRS Environmental Stress and Aquatic Monitoring | Duflot A.,CNRS Environmental Stress and Aquatic Monitoring | Marie S.,CNRS Environmental Stress and Aquatic Monitoring | And 3 more authors.
Journal of Applied Toxicology | Year: 2016

An increasing body of evidence suggests that sex steroids play an important role in the development and regulation of vertebrate immune defense. Therefore, compounds with estrogenic activity may influence the immune system via receptor-mediated pathways. The presence of estrogen receptors in immune cells and organs during the early stages of development may indicate that female steroid hormones are involved in the maturation of the fish immune system. This is of particular importance, as some marine fish are probably exposed to sources of exogenous estrogens while they reside in their estuarine nursery grounds. In this study, the influence of 17β-estradiol (E2) on estrogen receptor and cytokine gene expression was assessed in juvenile sea bass (Dicentrarchus labrax) together with characterization of the head kidney leukocyte populations and corresponding phagocytic activity during organ regionalization from 98 to 239 dph. E2 exposure, beginning at 90 dph resulted in indirect and delayed modifications of interleukin 1β and estrogen receptor α gene expression, which may affect B-lymphocyte proliferation in the sea bass head kidney. The E2 treatment of 120 dph fish led to an increase in estrogen receptor β2 and a decrease in transforming growth factor β1 gene expression, which coincided with decreased phagocytic activity of head kidney lymphocytes and monocytes/macrophages. Additionally, these changes were observed during developmental periods described as critical phases for B-lymphocyte development in mammals. Consequently, exogenous estrogens have the potential to modify the innate immune response in juvenile sea bass and to exert detrimental effects on head kidney development. © 2016 John Wiley & Sons, Ltd.


PubMed | Institute for Radiological Protection and Nuclear Safety and CNRS Environmental Stress and Aquatic Monitoring
Type: Journal Article | Journal: Ecotoxicology (London, England) | Year: 2016

Human activities have led to increased levels of various pollutants including metals in aquatic ecosystems. Increase of metallic concentrations in aquatic environments represents a potential risk to exposed organisms, including fish. The aim of this study was to characterize the environmental risk to fish health linked to a polymetallic contamination from former uranium mines in France. This contamination is characterized by metals naturally present in the areas (manganese and iron), uranium, and metals (aluminum and barium) added to precipitate uranium and its decay products. Effects from mine releases in two contaminated ponds (Pontabrier for Haute-Vienne Department and Saint-Pierre for Cantal Department) were compared to those assessed at four other ponds outside the influence of mine tailings (two reference ponds/department). In this way, 360 adult three-spined sticklebacks (Gasterosteus aculeatus) were caged for 28days in these six ponds before biomarker analyses (immune system, antioxidant system, biometry, histology, DNA integrity, etc.). Ponds receiving uranium mine tailings presented higher concentrations of uranium, manganese and aluminum, especially for the Haute-Vienne Department. This uranium contamination could explain the higher bioaccumulation of this metal in fish caged in Pontabrier and Saint-Pierre Ponds. In the same way, many fish biomarkers (antioxidant and immune systems, acetylcholinesterase activity and biometric parameters) were impacted by this environmental exposure to mine tailings. This study shows the interest of caging and the use of a multi-biomarker approach in the study of a complex metallic contamination.


PubMed | Institute for Radiological Protection and Nuclear Safety, CNRS Environmental Stress and Aquatic Monitoring and University of Reims Champagne Ardenne
Type: Journal Article | Journal: Fish physiology and biochemistry | Year: 2016

The aim of this study was to evaluate the effects of caging constraints on multiple fish biomarkers used during ecotoxicological studies (biometric data, immune and antioxidant systems, and energetic status). Two of these constraints were linked to caging: starvation and fish density in cages, and one in relation to the post-caging handling: a short transport. Three in situ experiments were conducted with three-spined sticklebacks (Gasterosteus aculeatus). The first experiment compared the effects of three densities (low, medium, and high). The second experiment compared effects of starvation in fish fed every two days with fish that were not fed. Finally comparisons between sticklebacks which have suffered a short car transport after caging and sticklebacks killed without preliminary transport were made. The lack of food had no effect on fish energetic reserves but negatively affected their condition index and their immune system. Transport and high density induced oxidative stress, defined as an overproduction of reactive oxygen species and a stimulation of the antioxidant system. These two constraints also harmed the leucocyte viability. In order not to have any impact on ecotoxicity biomarkers during in situ experiments, it is preferable to decrease fish density in cages, prevent transport before dissections, and feed fish when the caging lasts more than two weeks.


PubMed | CEA Cadarache Center, CNRS Environmental Stress and Aquatic Monitoring and University of Reims Champagne Ardenne
Type: Journal Article | Journal: Ecotoxicology (London, England) | Year: 2016

To get closer to the environmental reality, ecotoxicological studies should no longer consider the evaluation of a single pollutant, but rather combination of stress and their interaction. The aim of this study was to determine if responses of a fish to a sudden biological stress could be modified by a prior exposure to a chemical stress (a polymetallic contamination). For this purpose, in situ experiment was conducted in three ponds in the Haute-Vienne department (France). One pond was chosen for its high uranium concentration due to uranium mine tailings, and the two other ponds, which were not submitted to these tailings. Three-spined sticklebacks (Gasterosteus aculeatus) were caged in these ponds for 14days. After this period, fish were submitted to a biological stress, exerted by lipopolysaccharides injection after anesthesia, and were sacrificed 4days after these injections for multi-biomarkers analyses (leucocyte viability, phagocytic capacity and reactive oxygen species production, antioxidant peptide and enzymes, lipid peroxidation and DNA damage). The pond which received uranium mine tailings had higher metallic concentrations. Without biological stress, sticklebacks caged in this pond presented an oxidative stress, with increasing of reactive oxygen species levels, modification of some parts of the antioxidant system, and lipid peroxidation. Caging in the two most metal-contaminated ponds resulted in an increase of susceptibility of sticklebacks to the biological stress, preventing their phagocytic responses to lipopolysaccharides and modifying their glutathione contents and glutathione-S-transferase activity.


PubMed | IRSTEA, CNRS Laboratory of Oceanic Environments and Paleo-environments (EPOC), French Climate and Environment Sciences Laboratory, Free University of Colombia and 2 more.
Type: | Journal: Environmental science and pollution research international | Year: 2016

Quality assessment of environments under high anthropogenic pressures such as the Seine Basin, subjected to complex and chronic inputs, can only be based on combined chemical and biological analyses. The present study integrates and summarizes a multidisciplinary dataset acquired throughout a 1-year monitoring survey conducted at three workshop sites along the Seine River (PIREN-Seine program), upstream and downstream of the Paris conurbation, during four seasonal campaigns using a weight-of-evidence approach. Sediment and water column chemical analyses, bioaccumulation levels and biomarker responses in caged gammarids, and laboratory (eco)toxicity bioassays were integrated into four lines of evidence (LOEs). Results from each LOE clearly reflected an anthropogenic gradient, with contamination levels and biological effects increasing from upstream to downstream of Paris, in good agreement with the variations in the structure and composition of bacterial communities from the water column. Based on annual average data, the global hazard was summarized as moderate at the upstream station and as major at the two downstream ones. Seasonal variability was also highlighted; the winter campaign was least impacted. The model was notably improved using previously established reference and threshold values from national-scale studies. It undoubtedly represents a powerful practical tool to facilitate the decision-making processes of environment managers within the framework of an environmental risk assessment strategy.


PubMed | Laboratoire Of Parasitologie Mycologie, CNRS Environmental Stress and Aquatic Monitoring, IRSTEA and U.S. Department of Agriculture
Type: | Journal: Ecotoxicology and environmental safety | Year: 2016

The protozoa Toxoplasma gondii and Cryptosporidium parvum are public health priorities because their oocysts can persist in recreational, surface, drinking, river, and sea water sources for a long time. To evaluate the capacity of the freshwater crustacean Gammarus fossarum to accumulate T. gondii and C. parvum oocysts, gammarids were exposed to 200, 2000 or 20,000 oocysts per gammarid and per day for 21 days followed by 5 days of depuration. C. parvum DNA was detected by qPCR in G. fossarum in only one out of four pools for the highest concentration and after 14 days of exposure, and T. gondii DNA was detected after 7 days of exposure to the two highest concentrations. Our results document the capacity of G. fossarum to accumulate T. gondii in its tissues proportionally to the ambient concentration; the maximum number of oocysts was detected in gammarid tissues after exposure to 20,000 oocysts per day. Mean values of 3.26 (3), 21.71 (15.18), and 17.41 (10.89) oocysts were detected in gammarids after 7, 14, and 21 days, respectively, and after 5 days of depuration, T. gondii oocysts were still present in gammarid tissues. These results show for the first time that a freshwater crustacean can bioaccumulate T. gondii oocysts, suggesting that G. fossarum is a potential effective bioindicator of protozoan contamination in biomonitoring studies. Moreover, due to its key position in freshwater food webs, G. fossarum could also play a role in the trophic transfer of protozoa.


PubMed | Laboratoire Of Parasitologie Mycologie and CNRS Environmental Stress and Aquatic Monitoring
Type: Journal Article | Journal: Journal of applied microbiology | Year: 2016

The objective of this study was to evaluate if freshwater bivalves can be used to detect the presence of Toxoplasma gondii in water bodies.Zebra mussels (Dreissena polymorpha) were caged for 1 month upstream and downstream of the discharge points of wastewater treatment plants (WWTPs). Physiological status was assessed to assure good health of bivalves during transplantation. The presence of T. gondii was investigated in mussel tissues by qPCR. In autumn, T. gondii was detected in mussels caged downstream of the discharge points of two WWTPs. In spring, it was detected upstream of one WWTP.For the first time, T. gondii DNA has been shown in a continental mollusc in environmental conditions. This highlights the interest of an active approach that could be applied independently of the presence or accessibility of autochthonous populations, and underlines the presence of T. gondii in natural waters under pressure of WWTP discharge at a certain time of the year.This study shows that transplanted zebra mussels could be used as biosamplers to reveal contamination of freshwater systems by T. gondii.


PubMed | CNRS Environmental Stress and Aquatic Monitoring, CNRS Training and Research Center on Mediterranean Environments and CNRS Transfers and Interactions in Hydrosystems and Soils
Type: | Journal: The Science of the total environment | Year: 2016

The levels and fate of phthalate metabolites have been poorly evaluated in fish, despite their potential ecotoxicological impacts. The present study aims to characterize the levels of phthalate metabolites in muscle tissue of yellow eels (Anguilla anguilla) from two coastal Mediterranean lagoons, during three sampling periods. Nine phthalate metabolites were detected in >70% of the samples. Slightly higher levels of phthalate metabolites were detected in March and June compared to October, suggesting possible seasonal variations in environmental release and/or phthalate metabolization process by eels. The large sample size (N=117) made it possible to explore correlations between phthalate metabolites levels and individual parameters, such as body length, age, body condition and hepatic histo-pathologies. Body length and estimated age poorly correlated with phthalate metabolites, suggesting that eels did not accumulate phthalates during growth, contrary to persistent compounds. Eels presented different grades of hepatic fibrosis and lipidosis. A negative correlation was found between the severity of these pathologies in the liver and the sum of phthalate metabolites levels, supporting the hypothesis that eels with damaged liver are less able to metabolize xenobiotics.


PubMed | CNRS Environmental Stress and Aquatic Monitoring
Type: | Journal: Environmental science and pollution research international | Year: 2016

The aim of this study was to evaluate the coupled impact of an herbicide, ethofumesate, and temperature on the cellular energy metabolism of juvenile roach, especially on the glycolysis pathway. Juvenile roach were exposed to 0, 0.5, 5, and 50g/L of ethofumesate for 7days in laboratory conditions at two temperatures (10 and 17C). The energy reserves (carbohydrate, lipid, and protein) were quantified, since the availability of substrates regulates the glycolysis. Then, the glycolysis was studied at the biochemical level by the measurement of the glycolytic flux and at the molecular level with the measurement of the relative expression of four genes encoding for glycolysis enzymes. This study revealed different effect of ethofumesate on the glycolysis pathway according to the temperature of exposure. Indeed, at 10C, it appeared that only the molecular regulation level was affected, whereas, at 17C, ethofumesate acted on the biochemical level. The differences observed between the two exposures imply the establishment of different strategies in order to maintain to cope with stress according to the temperature of exposure.

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