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1.
Int J Environ Health Res ; : 1-12, 2024 May 03.
Article de Anglais | MEDLINE | ID: mdl-38700266

RÉSUMÉ

Bisphenol A (BPA) is a chemical compound extensively employed in plastic manufacturing, and this pollutant has been detected in diverse aquatic organisms, notably bivalves. In order to comprehend the ecological and toxicological consequences of BPA Bisphenol A in these organisms, it is essential to examine the physiological and biochemical effects and identify areas where our understanding is lacking. This knowledge is crucial for determining the environn ental threat posed by bisphenol A and assisting decision-makers in establishing the appropriate priorities. This investigation aimed to assess the impact of BPA on the biochemical and physiological parameters of the freshwater mussel Potomida littoralis. In a laboratory setting, mussels were subjected to two different levels of BPA (20 and 100 µg/L) for a duration of 21 days. Filtration rate was calculated from the clearance of neutral red, fed to mussels at different BPA concentrations. The mussel's filtration rate capacity declined as BPA exposure intensified, potentially due to the mussel's attempt to close its valves and minimize BPA absorption, thus preventing cellular damage. In the digestive gland tissue, key antioxidant and detoxification defenses, including catalase (CAT) activity, glutathione-S-transferase (GST) activity, and levels of H2O2 and glutathione (GSH), were activated, particularly at the 100 µg/L BPA concentration. This activation helped protect against lipid damage at higher BPA concentrations. This study underscores the significance of preventing and regulating BPA release into the environment to avert detrimental consequences for aquatic ecosystems.

2.
Mar Pollut Bull ; 193: 115230, 2023 Aug.
Article de Anglais | MEDLINE | ID: mdl-37406401

RÉSUMÉ

The health status of Mytilus galloprovincialis native from a polluted habitat was surveyed before and after 30 and 60 days of in situ transplantation and in vivo experiments. The results showed a reduction in filtration rate by 24 % and 45 %, respectively, after 60 days of in vivo and in situ experiments compared to the rates at polluted sites. The respiration rate reached a minimum of 0.081 ± 0.05 mg O2.L-1 after 60 days of in situ transplantation. Moreover, the antioxidant activities were changed in a time-dependent manner for both transplantation conditions. The highest superoxide dismutase and catalase activities corresponded to the stressed mussels and declined by 76 % and 54 %, respectively, after 60 days of in situ transplantation. Changes in lipid peroxidation and acetylcholinesterase activity were observed in internal organs following 60 days of transplantation. At this time slot, the lowest content of metals and microplastics was also noticed.


Sujet(s)
Mytilus , Polluants chimiques de l'eau , Animaux , Acetylcholinesterase , Décontamination , Matières plastiques , Polluants chimiques de l'eau/analyse , Antioxydants , Écosystème , Marqueurs biologiques
3.
Animals (Basel) ; 13(4)2023 Feb 07.
Article de Anglais | MEDLINE | ID: mdl-36830370

RÉSUMÉ

The effects of pharmaceutical under aquatic biota are still not well established. In this investigation, we assessed the results of a common pharmaceutical's, triclosan (TCS), treatment on physiological and biochemical status of the Mediterranean mussels. Filtration and respiration rates were statistically reduced after treatment with highest considered concentration TCS2 = 100 µg·L-1. However, no modification (p > 0.05) was detected after treatment with TCS1 = 50 µg·L-1. For biochemical responses, oxidative stress parameters including H2O2 level and antioxidant enzymes were enhanced following concentration in considered organs. In parallel, Malondialdheyde content was measured in mussels after TCS treatment and lipid peroxidation occurred at high TCS concentration. Neurotoxicity evaluated by acetylcholinesterase (AChE) activity was induced in gills and digestive glands after exposure to TCS2. Overall, physiological impairment, oxidative stress, lipid peroxidation and neurotoxicity could be induced by triclosan in mussels. The association of physiological and biochemical biomarkers constitute a useful tool to measure the impact of pharmaceuticals in marine organism.

4.
Mar Pollut Bull ; 185(Pt A): 114252, 2022 Dec.
Article de Anglais | MEDLINE | ID: mdl-36272318

RÉSUMÉ

An experiment conducted with 'open microcosm' made by connected sedimentary compartments with different qualities was for 30 days to evaluate the migratory behaviour of nematodes as induced by exposure to pyrene. The nematofauna was collected along with sediment from a reference site in Bizerte lagoon. Following one week acclimatization period, the populated sediments were topped with azoic sediments, with a pyrene concentration of 150 µg kg-1. The concentration of pyrene from sediments was measured on a weekly basis. A stable status of nematode assemblages was reached between the upper and lower compartments in each microcosm, whatever the treatment type. An upward exploratory phase was observed during the first two weeks within the assemblages, possibly induced by the repellent chemodetection of pyrene. This observation was confirmed by the toxicokinetic properties and molecular interactions of pyrene with the germ-line development Protein 3 and sex-determining protein of Caenorhabditis elegans as nematode model.


Sujet(s)
Nematoda , Polluants chimiques de l'eau , Animaux , Sédiments géologiques , Toxicocinétique , Polluants chimiques de l'eau/toxicité , Nematoda/physiologie , Pyrènes/toxicité , Pyrènes/métabolisme , Caenorhabditis elegans
5.
Toxicol Mech Methods ; 32(8): 569-579, 2022 Oct.
Article de Anglais | MEDLINE | ID: mdl-35313786

RÉSUMÉ

Purpose: In recent years, the increase in the biopesticides synthesis for alternative agricultural uses has required their impacts study. Among these compounds, several of them are known to exert endocrinedisrupting (EDs) effects causing deregulation of physiological functions affecting cell signaling pathways involved in neural cell differentiation leading to developmental neurotoxicity. The objective of our study was to determine the impact of the biopesticide A6 structurally related to estrogenic EDs on zebrafish larvae, to define its toxicity, the mechanisms responsible, and to monitor the locomotors activity at nanomolar concentrations (0. 0.5, 5 and 50 nM).Materials and methods: Using imaging analysis tools, immunohistochemistry, quantitative PCR, and an automated behavior recording system (Zebrabox) we were able to assess these effects.Results: We have shown through its blue fluorescence properties that it accumulates in different parts of the body such as the intestine, adipose tissue, muscles, yolk sac and head. A6 also disrupted swimming behavior by affecting the expression of tyrosine hydroxylase (TH) in dopaminergic neurons.Conclusions: In conclusion, our study provided a mechanistic understanding of the A6 neurotoxic effect which could be the result of its binding to the estrogen receptor.


Sujet(s)
Neurochimie , Pesticides , Animaux , Expression des gènes , Larve , Tyrosine 3-monooxygenase/génétique , Tyrosine 3-monooxygenase/métabolisme , Danio zébré/génétique , Danio zébré/métabolisme
6.
J Hazard Mater ; 421: 126789, 2022 01 05.
Article de Anglais | MEDLINE | ID: mdl-34365235

RÉSUMÉ

Microbial communities inhabiting soil-water-sediment continuum in coastal areas provide important ecosystem services. Their adaptation in response to environmental stressors, particularly mitigating the impact of pollutants discharged from human activities, has been considered for the development of microbial biomonitoring tools, but their use is still in the infancy. Here, chemical and molecular (16S rRNA gene metabarcoding) approaches were combined in order to determine the impact of pollutants on microbial assemblages inhabiting the aquatic network of a soil-water-sediment continuum around the Ichkeul Lake (Tunisia), an area highly impacted by human activities. Samples were collected within the soil-river-lake continuum at three stations in dry (summer) and wet (winter) seasons. The contaminant pressure index (PI), which integrates Polycyclic aromatic hydrocarbons (PAHs), alkanes, Organochlorine pesticides (OCPs) and metal contents, and the microbial pressure index microgAMBI, based on bacterial community structure, showed significant correlation with contamination level and differences between seasons. The comparison of prokaryotic communities further revealed specific assemblages for soil, river and lake sediments. Correlation analyses identified potential "specialist" genera for the different compartments, whose abundances were correlated with the pollutant type found. Additionally, PICRUSt analysis revealed the metabolic potential for pollutant transformation or degradation of the identified "specialist" species, providing information to estimate the recovery capacity of the ecosystem. Such findings offer the possibility to define a relevant set of microbial indicators for assessing the effects of human activities on aquatic ecosystems. Microbial indicators, including the detection of "specialist" and sensitive taxa, and their functional capacity, might be useful, in combination with integrative microbial indices, to constitute accurate biomonitoring tools for the management and restoration of complex coastal aquatic systems.


Sujet(s)
Hydrocarbures aromatiques polycycliques , Polluants chimiques de l'eau , Marqueurs biologiques , Écosystème , Surveillance de l'environnement , Sédiments géologiques , Humains , Lacs , Hydrocarbures aromatiques polycycliques/analyse , ARN ribosomique 16S/génétique , Rivières , Sol , Polluants chimiques de l'eau/analyse
7.
Environ Sci Pollut Res Int ; 29(11): 16529-16548, 2022 Mar.
Article de Anglais | MEDLINE | ID: mdl-34651273

RÉSUMÉ

A microcosm experiment was carried out to determine how benzo(a)pyrene (BaP) may affect marine meiofauna community, with a main emphasis on nematode structure and functional traits. Three increasing concentrations of BaP (i.e. 100, 200 and 300 ng/l, respectively) were used for 30 days. The results revealed a gradual decrease in the abundance of all meiobenthic groups (i.e. nematodes, copepods, amphipods, polychaetes and oligochaetes), except for isopods. Starting at concentrations of 200 and 300 ng/l BaP, respectively, significant changes were observed at community level. At taxonomic level, the nematode communities were dominated at the start of the experiment and also after being exposed or not to BaP by Odontophora villoti, explicable through its high ecologic ubiquity and the presence of well-developed chemosensory organs (i.e. amphids), which potentially increased the avoidance reaction following exposure to this hydrocarbon. Moreover, changes in the activity of several biochemical biomarkers (i.e. catalase 'CAT', gluthatione S-transferase 'GST', and ethoxyresorufin-O-deethylase 'EROD') were observed in the nematode species Oncholaimus campylocercoides, paralleled by significant decreases in CAT activity for non-gravid females compared to controls at concentrations of 25 ng/l BaP and associated with significant increase in GST and EROD activities for both types of individuals.


Sujet(s)
Copepoda , Nematoda , Animaux , Benzo[a]pyrène , Marqueurs biologiques , Cytochrome P-450 CYP1A1
8.
Environ Sci Pollut Res Int ; 29(2): 2566-2578, 2022 Jan.
Article de Anglais | MEDLINE | ID: mdl-34370198

RÉSUMÉ

A microcosm bioassay was designed to assess the efficacy of wastewater treatment methods used in sewage plants. The taxonomic and feeding characteristics of a meiobenthic nematode assemblage from Ghar El Melh lagoon (Tunisia) were used to achieve this goal. Nematode assemblages were exposed for 30 days to untreated wastewater (UW) obtained from the sewage treatment plant of Sidi Ahmed (Tunisia) and three mixtures with treated wastewater (TW33 = 33%, TW66 = 66%, and TW100 = 100%). Concerning the nematode abundance, the exposure to either treated wastewater (TW33-100) or untreated wastewater (UW) had no significant effect. In contrast, Shannon-Wiener index and Pielou's Evenness were clearly reduced by contamination with both types of wastewater, with a more pronounced negative impact prior to treatment in the sewage plant. The multivariate analyzes revealed a change in the taxonomic composition of the nematofauna in response to the contamination by untreated or treated wastewater. The relative abundances of species in wastewater replicates compared to controls reflected this taxonomic restructuring. Finally, Ascolaimus elongatus, Terschellingia communis, and Kraspedonema octogoniata were less represented in all experimentally treated units and could be considered as 'sensitive taxa to wastewater'. While, Paracomesoma dubium, appears to be a 'tolerant and/or opportunistic' species, showing increased relative abundances under all wastewater treatments.


Sujet(s)
Nematoda , Purification de l'eau , Animaux , Eaux d'égout , Tunisie
9.
Environ Pollut ; 292(Pt A): 118281, 2022 Jan 01.
Article de Anglais | MEDLINE | ID: mdl-34626706

RÉSUMÉ

This study was conducted to assess the impact and efficiency of the bioaugmentation as a bioremediation technique in annoying effects of a polycyclic aromatic hydrocarbon (phenanthrene) on a community of free-living nematodes from Bizerte bay (Tunisia). For this purpose, closed microcosms were exposed to three doses of phananthrene (0.1 µg kg-1, 1 µg kg-1 and 10 µg kg-1), in combination or not with a strain of Shewanella oneidensis. After 40 days of the exposure, results were obtained at the numerical, taxonomic and feeding levels. The results of univariate analyses revealed significant decreases in most univariate indices for phenanthrene treated communities compared to controls, with a discernible increase in the proportion of epistrate feeders. After bioaugmentation, similar patterns were observed for univariate and multivariate analyses, with the exception of the highest treatment, which showed no difference from the controls. The results obtained showed that the bioaugmentation with Shewanellea oneidensis was highly effective in reducing the negative impact of the highest dose of phenanthrene (10 µg kg-1 Dry Weight) tested on meiobenthic nematodes. Furthermore, a combination of Shewanellea oneidensis and four omnivore-carnivore nematode taxa could be suggested as an effective method in the bioremediation of phenanthrene-contaminated sediment.


Sujet(s)
Nematoda , Phénanthrènes , Shewanella , Animaux , Dépollution biologique de l'environnement , Sédiments géologiques
10.
Chemosphere ; 287(Pt 3): 132262, 2022 Jan.
Article de Anglais | MEDLINE | ID: mdl-34543897

RÉSUMÉ

Coastal marine systems are the most sensitive zones to emerging pollutants. The present study aims to investigate the effect of Diuron on the meiofaunal assemblages, collected from the Bizerte channel (Tunisia). Microcosm experiments were set up using four increasing Diuron concentrations [D1 (10 ng g-1 dry weight (DW)), D2 (50 ng g-1 DW), D3 (250 ng g-1 DW) and (1250 ng g-1 DW)] compared to non-contaminated sediments (controls) and all plots were incubated for 30 days. Our results show that Diuron-supplemented sediments provoked the significant decrease of meiofaunal abundance as well as a change in nematodes' diversity and structure composition. All univariate indices, as well as the cumulative k-dominance, were lower in the Diuron than the control plot. Additionally, the ordination of treatments according to the two-dimensional nMDS plots analysis showed a clear structural separation of the Diuron treated replicates from the controls based on the functional groups lists. These current data emphasize the utility of the use of biological traits in the detection of disturbances in the aquatic biotope.


Sujet(s)
Nematoda , Polluants chimiques de l'eau , Animaux , Climat , Diuron/toxicité , Surveillance de l'environnement , Sédiments géologiques , Phénotype , Tunisie , Polluants chimiques de l'eau/analyse , Polluants chimiques de l'eau/toxicité
11.
Mar Pollut Bull ; 169: 112556, 2021 Aug.
Article de Anglais | MEDLINE | ID: mdl-34082359

RÉSUMÉ

Organophosphorus derivatives are widely used in human health care and have been detected in aquatic ecosystems. These compounds may pose significant risks to non-target exposed organisms and only limited studies are available on bioconcentration and the effects of organophosphorus derivatives on marine organisms. The aim of this work was to evaluate the possible toxic effects of two concentrations (20 and 40 µg/L) of γ-oximo- and γ-amino-phosphonates and phosphine oxides in mediterranean clams Ruditapes decussatus exposed for 14 days using different biomarkers and the changes of filtration and respiration rate. The use of clams in ecotoxicity evaluation is thus mandatory to assess the feasibility of assessing oxidative stress on R. decussatus after being exposed to γ-oximo- and γ-amino-phosphonates and phosphine oxides. The oxidative status was analyzed by measuring oxidative stress biomarkers RNS and ROS production in mitochondria, superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferases (GSTs), lipid peroxidation (LPO) and acetylcholinesterase (AChE), whose alteration was indicative of organophosphorus exposure, in both gills and digestive gland of the clams. No significant alterations in RNS, ROS production, SOD, CAT and AChE activities and MDA content were observed in both organs of clams treated with γ-oximophosphine oxides. It was possible then to hypothesize that γ-oximophosphine oxides may have probably exerted an incomplete alteration of antioxidant defenses and damage, which was changed by the activation of defense mechanisms. On the contrary, oxidative stress parameters were changed after exposure to γ-amino-phosphonates and phosphine oxides. In addition, metals accumulation, filtration and respiration rates were altered following exposure to all the studied organophosphorus compounds.


Sujet(s)
Bivalvia , Phosphonates , Polluants chimiques de l'eau , Animaux , Marqueurs biologiques/métabolisme , Bivalvia/métabolisme , Catalase/métabolisme , Écosystème , Branchies/composition chimique , Peroxydation lipidique , Phosphonates/métabolisme , Stress oxydatif , Oxydes/toxicité , Phosphines , Superoxide dismutase/métabolisme , Polluants chimiques de l'eau/analyse
12.
Environ Pollut ; 276: 116759, 2021 May 01.
Article de Anglais | MEDLINE | ID: mdl-33639491

RÉSUMÉ

The majority of experimental studies carried out to date, regarding the effects of pollutants on meiofauna have been conducted by means of closed systems, and rarely using open ones. The current work explored the impact of three Polycyclic Aromatic Hydrocarbons (PAHs), anthracene, pyrene and benzo[a]pyrene, applied alone or combined, on meiobenthic nematodes using both systems. The results revealed that single PAHs impacted the nematofauna similarly in closed or open systems with a higher toxicity observed for benzo[a]pyrene. However, the closed microcosms contaminated with PAHs became organically enriched, resulting in more non-selective deposit feeders and omnivores-carnivores. Taxonomic and functional effects related to combinations of PAHs were close to those of individual treatments in closed systems, however, for open ones, the outcomes were different. The caudal morphology influenced the response of taxa during their avoidance/endurance of hydrocarbons in open systems where the effects of PAHs mixtures appeared not only additive but also synergetic. Based on the results of the study, the use of open systems is preferred to closed ones as the research outcomes were more accurate and representing better conditions prevailing in nature.


Sujet(s)
Nematoda , Hydrocarbures aromatiques polycycliques , Animaux , Anthracènes/toxicité , Benzo[a]pyrène/toxicité , Hydrocarbures aromatiques polycycliques/toxicité , Pyrènes
13.
Environ Pollut ; 277: 116727, 2021 May 15.
Article de Anglais | MEDLINE | ID: mdl-33640809

RÉSUMÉ

The response taxonomic and trophic of meiobenthic organisms, especially marine nematodes to polybrominated diphenyl ether (BDE-47) was studied using a community from Bizerte lagoon (Nord-East Tunisia). Four concentrations of BDE-47 [D1 (2.5 µg/kg dw), D2 (25 µg/kg dw), D3 (50 µg/kg dw), and D4 (100 µg/kg dw)] were applied, and responses were determined 30 days after exposure. Species abundance and all univariate indices were significantly affected in all treated microcosms compared to the control. The non-parametric cluster based on species abundance separated the nematode population into two groups: control + all treated microcosms. After grouping nematode species according to their trophic diversity, their abundance showed differential responses. The non-metric multi-dimensional scaling analysis and cumulative k-dominance based on the abundance of trophic groups abundances reflected significant separation between the control microcosm and each treatment condition. The correspondence analysis 2D plot generated from nematode species and trophic groups abundance showed the control microcosm was dominated by microvores, represented by two species of Terschellingia. However, when treated with the highest concentration of BDE-47, the community was occupied by the resistant trophic groups of facultative predators and epigrowth feeders represented by Metoncholaimus pristiurus and Paracomesoma dubium, respectively.


Sujet(s)
Éthers de polyhalogénophényle , Nematoda , Animaux , Éthers de polyhalogénophényle/toxicité , Tunisie
14.
Sci Total Environ ; 770: 145251, 2021 May 20.
Article de Anglais | MEDLINE | ID: mdl-33508666

RÉSUMÉ

Trophic web structuring in aquatic sediments is dependent on the biological interactions between metazoans and microbial communities. The presence of pollutants in these biotas can therefore impact the meiofauna structure via the modification of the microbial communities. The current study examined in a laboratory bioassay the response of meiobenthic communities, particularly marine nematode taxa from the Bizerte Lagoon to the effect of the most detected polybrominated diphenyl ether in this aquatic environment, BDE-47. Four doses [D1 (2.5 ppb Dry weight (DW)), D2 (25 ppb DW), D3 (50 ppb DW), and D4 (100 ppb DW)] were gradually applied and sediment microcosms were incubated for 30 days in the presence or absence of meiofauna. Our results show that BDE-47-enriched sediments decreased the meiofaunal taxa and bacterial abundance. A lower taxonomic diversity of the nematodes' general structure was observed with all doses used. The numerical analysis of the two dimensional (2D) non-metric multidimensional scaling (nMDS) plots and the evolution of the relative abundances of each functional group of nematode genus assemblages revealed that the abundance of all biological traits was modified. Nevertheless, only three of the functional traits, adult length, feeding group, and amphid shape, showed a clear difference between the control and the treated microcosms. The similarity percentage analysis (SIMPER) revealed that the average dissimilarity between nematode genera communities and biological traits increased with BDE-47-enriched sediments. The nMDS second-stage ordination of inter-matrix rank correlations for matrices including genera and biological traits showed that the amphid shape was the functional trait closest to the generic distribution. Finally, the Principal Component Analysis (PCA) for the nematode biological traits and bacteria indicated a positive correlation of these microbes with the functional groups [1A, Cr, and ef], and a negative correlation only with the "cla"-type tail shape.


Sujet(s)
Nematoda , Polluants chimiques de l'eau , Animaux , Bactéries , Sédiments géologiques , Éthers de polyhalogénophényle/analyse , Polluants chimiques de l'eau/analyse
15.
Biomarkers ; 26(3): 240-247, 2021 May.
Article de Anglais | MEDLINE | ID: mdl-33459570

RÉSUMÉ

CONTEXT: The Au-TiO2NPs have a wide range of applications and can easily enter the cells. Due to their properties, they can cause toxicity. OBJECTIVE: It was aimed to test the toxic effects of Au-TiO2 NPs in the brain, heart, kidney and liver of rats in this work. MATERIALS AND METHODS: All used rats in this work were treated using diverse concentrations (doses) of NPs (100 and 200 mg/kg bw) for 21 days. SOD, CAT, AChE activities and MDA, H2O2, NO contents were evaluated in different organs. RESULTS: The Au-TiO2 NPs exposure induced biochemical changes in different organs of rats in view of oxidative stress and neurotoxicity by the alteration of the activity of the enzyme of neurotransmitter (AChE activity). CONCLUSION: The Au-TiO2 NPs have the potential to interact with rat's biochemical status and cause undesirable effects. One of those damaging effects was oxidative stress and neurotoxicity. CLINICAL SIGNIFICANCE: The study signifies the impact of usage of Au-TiO2 NPs in the medical field for further exploration.


Sujet(s)
Encéphale/effets des médicaments et des substances chimiques , Or/toxicité , Nanoparticules métalliques/toxicité , Syndromes neurotoxiques/étiologie , Stress oxydatif/effets des médicaments et des substances chimiques , Titane/toxicité , Animaux , Marqueurs biologiques/métabolisme , Encéphale/métabolisme , Rein/effets des médicaments et des substances chimiques , Rein/métabolisme , Rein/anatomopathologie , Foie/effets des médicaments et des substances chimiques , Foie/métabolisme , Foie/anatomopathologie , Mâle , Myocytes cardiaques/effets des médicaments et des substances chimiques , Myocytes cardiaques/métabolisme , Myocytes cardiaques/anatomopathologie , Syndromes neurotoxiques/métabolisme , Syndromes neurotoxiques/anatomopathologie , Rat Wistar , Facteurs temps
16.
Environ Technol ; 42(23): 3651-3662, 2021 Sep.
Article de Anglais | MEDLINE | ID: mdl-32149584

RÉSUMÉ

The phosphate fertilizer and phosphoric acid industries increase phosphogypsum levels in the aquatic environment leading to various disturbing effects. In the present work, we investigated the bio-uptake of heavy metals following the exposure of Ruditapes decussatus to three concentrations of phosphogypsum, 10, 20 and 40 g kg-1, under laboratory conditions. The amounts of Zn, Cd and Pb in several organs of the clam Ruditapes decussatus was determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). Phosphogypsum acts on the behaviour of R. decussatus by increasing filtration rates. The most treatments showed significantly higher metal concentration in all tissues than the controls. Excavation behaviour was altered in treated bivalves compared to controls. The filtration rate (FR) of clams was significantly affected by exposure to phosphogypsum. Indeed, FR increased in clams exposed to phosphogypsum. Phosphogypsum has decreased SOD, CAT and MDA activities in the gills, digestive gland, gonad and muscles according to the concentration indicating a defense against oxidative stress. AChE was significantly inhibited in clams from all the sampling sites compared to controls. The considered parameters could be useful biomarkers for the evaluation of phosphogypsum toxicity in threatened biota. This study was conducted as part of a further investigation into the use of a comprehensive approach combining chemical and biological parameters to assess the health status of the Gabes gulf population. It provides the first database referring to phosphogypsum contamination and its biological effect in this ecosystem. The present study fills in a needed gap in the literature.


Sujet(s)
Bivalvia , Polluants chimiques de l'eau , Animaux , Sulfate de calcium , Écosystème , Branchies , Phosphore , Polluants chimiques de l'eau/analyse , Polluants chimiques de l'eau/toxicité
17.
Aquat Toxicol ; 228: 105632, 2020 Nov.
Article de Anglais | MEDLINE | ID: mdl-33010638

RÉSUMÉ

An experiment was carried out using microcosms to evaluate the impact of the fluoroquinolone antibiotic on nematode trophic groups structure and bacterial abundance. Sediment samples were experimentally enriched with four increasing doses of ciprofloxacin [D1 (50 ppm), D2 (100 ppm), D3 (200 ppm) and D4 (500 ppm)] and compared to non-enriched sediments (used as control). Ciprofloxacin changed the trophic composition of nematodes taxa where the relative abundance of microvores (M), epigrowth feeders (EF) and ciliate consumers (CF), raised in a control microcosm, was highly affected and significantly decreased in response to the increasing doses. Nevertheless, the abundance of deposit feeders (DF), optional predators (FP) and exclusive predators (Pr) showed a significant increase. Results from the multivariate analysis showed a clear impact of this antibiotic on nematode trophic assemblages. Microcosms treated with the three highest doses [D2, D3 and D4] were different from the control. The exceptions were those treated with the lowest dose, D1, and which were grouped with the control. The SIMPER analysis results showed that the average dissimilarity continuously increased in the treated microcosms compared to the control. Furthermore, our results have shown that ciprofloxacin also leads to a significant decrease in bacterial density with the highest dose, which could explain the results obtained for nematode trophic groups distribution. Thus, the bacteriophages nematodes only use bacteria as a nutrition source and the lack or presence in small quantity of this food could induce a decrease in their abundance as well as changing of nematodes groups repartition. Our work demonstrates that the nematode responses were dependent on sediment enrichment with ciprofloxacin and opens new perspectives on the potential impact of antibiotics on functional nematode diversity.


Sujet(s)
Antibactériens/toxicité , Organismes aquatiques/effets des médicaments et des substances chimiques , Bactéries/croissance et développement , Ciprofloxacine/toxicité , Écosystème , Sédiments géologiques/composition chimique , Nematoda/physiologie , Animaux , Bactéries/effets des médicaments et des substances chimiques , Analyse de regroupements , Géographie , Sédiments géologiques/microbiologie , Région méditerranéenne , Analyse multifactorielle , Nematoda/effets des médicaments et des substances chimiques , Densité de population , Analyse en composantes principales , Polluants chimiques de l'eau/toxicité
18.
Ecotoxicol Environ Saf ; 205: 111084, 2020 Dec 01.
Article de Anglais | MEDLINE | ID: mdl-32810644

RÉSUMÉ

A microcosm experiment was conducted to evaluate the impacts of the fluoroquinolone antibiotic ciprofloxacin on meiobenthic taxa abundance, nematode genus structure, and functional trait parameters. Sediment samples were experimentally enriched with four different doses of ciprofloxacin [D1 (50 ppm Dry weight 'DW'), D2 (100 ppm DW), D3 (200 ppm DW), and D4 (500 ppm DW)] and were then compared with non-enriched sediments (controls). After one month of exposure, the data showed that ciprofloxacin had altered the meiofaunal taxa abundance. A change in the structure of nematofaunal genera was observed, particularly with the highest dose (D4), which was characterized by the lowest taxonomic diversity. The SIMPER analysis revealed that the average dissimilarity between nematode communities increased with increasing doses of ciprofloxacin. Two dimensional (2D) non-metric multidimensional scaling (nMDS) plots and relative abundances of functional groups of nematode genus assemblages revealed that all functional trait abundances were affected, particularly with the highest dose. However, only the amphid shape and feeding group functions showed a clear distribution separation between the control and ciprofloxacin treatments. The nMDS second-stage ordination of inter-matrix rank correlations for matrices including genus and functional traits showed that the tail shape was the closest functional trait to the generic distribution. Thus, only the curves of cumulative dominance related to the tail shape mirrored discernibly the sedimentary concentrations in ciprofloxacin.


Sujet(s)
Antibactériens , Ciprofloxacine , Nematoda , Animaux , Sédiments géologiques/composition chimique , Analyse multifactorielle
19.
Mar Pollut Bull ; 157: 111375, 2020 Aug.
Article de Anglais | MEDLINE | ID: mdl-32658716

RÉSUMÉ

At the end of March 2020, ivermectin was confirmed as a drug for COVID-19 treatment. A significant amount of ivermectin could deposit into sediments of the semi-closed Mediterranean Sea, where three European COVID-19 epicenters are located: Italy, Spain, and France. Meiobenthic nematodes were exposed to three ivermectin doses (1.8 ng.g-1, 9 ng.g-1, and 18 ng.g-1) for 10 days. Ivermectin caused a great reduction in abundance. However, the diversity indices decreased only at high doses. Ivermectin disadvantaged the 1B-Cr-Id functional type (non-selective deposit feeders and nematodes with circular or indistinct amphids) and benefited the 2A-REL-Sp type (epistrate feeders and nematodes with rounded or elongated loop amphids). Thus, Trophic Diversity and Amphideal Diversity index values increased with sedimentary ivermectin enrichment. Large amphideal foveas were more efficient for 2A-REL-Sp nematodes to avoid ivermectin. The responses of the functional type 2A-REL-Sp and corresponding taxa predict post-COVID-19 environmental concerns and the bioaccumulation of ivermectin in seafoods.


Sujet(s)
Antiviraux/toxicité , Infections à coronavirus , Ivermectine , Nematoda , Pandémies , Pneumopathie virale , Animaux , Betacoronavirus , COVID-19 , Infections à coronavirus/traitement médicamenteux , France , Humains , Italie , Ivermectine/toxicité , Mer Méditerranée , SARS-CoV-2 , Espagne , Traitements médicamenteux de la COVID-19
20.
Pestic Biochem Physiol ; 165: 104463, 2020 May.
Article de Anglais | MEDLINE | ID: mdl-32359554

RÉSUMÉ

Cypermethrin (Cyp) is a kind of pyrethroids compound that is broadly used against different species of insects and pests. Cyp can also elicit a range of neurotoxic, immunotoxic, genotoxic and reproductive toxic effects on various experimental organisms. The aim of this study was to evaluate the protective effects of Hibiscus sabdariffa against the toxicity damage induced by Cyp exposure. The Hibiscus sabdariffa calyxes extract was given to mice (200-500 mg/kg bw). The mice, which were treated with Cyp and Hibiscus sabdariffa, were divided into six groups of six mice each. Groups I, IV and VI were used as control and groups II CYP control (20 mg/kg body weight)., groups III and V were treated with Hibiscus sabdariffa extract (200 and 500 mg/kg body weight) plus (20 mg/kg body weight) for 21 days Furthermore, HPLC was used to identify the compound fraction. This result showed Cyp -induced biochemical changes in all organs of mice. Cyp caused decreased CAT activity, inhibition of AChE activity and increased the levels of H2O2 and MDA in brain, heart, liver and kidney. Hibiscus sabdariffa exhibited antioxidant effect and significantly attenuated the neurotoxicity of Cyp. Hibiscus sabdariffa exhibits neuroprotective effects and can be an effective and novel alternative approach to reduce the risk caused by pyrethroid compound.


Sujet(s)
Hibiscus , Pyréthrines , Animaux , Peroxyde d'hydrogène , Souris , Stress oxydatif , Extraits de plantes
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