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| Registros recuperados: 83 | |
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| Gueguen, Marielle; Bardouil, Michele; Baron, Regis; Lassus, Patrick; Truquet, Philippe; Massardier, Julie; Amzil, Zouher. |
| Contamination of shellfish by paralytic shellfish poisoning ( PSP) toxins poses an economic threat to shellfish farmers. As contaminated shellfish cannot be harvested for long periods of time, it would be very useful to develop processes to optimise and shorten their detoxification. In this study, Pacific oysters Crassostrea gigas were first experimentally contaminated over a period of 13 days with a continuous flow of toxic Alexandrium minutum cultures at concentrations ranging from 150 to 200 cell ml(-1) ( toxin content after 13 days of contamination 438 mu g STX equiv. 100 g(-1) wet weight). Then, two different detoxification treatments were tested and showed detoxification rates greater than those observed in coastal environments. The first treatment... |
| Tipo: Text |
Palavras-chave: Alexandrium minutum; Crassostrea gigas; Detoxification; Inorganic matter; Organic matter; PSP; Paralytic shellfish poisoning. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3896.pdf |
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| Reveillon, Damien; Abadie, Eric; Sechet, Veronique; Brient, Luc; Savar, Veronique; Bardouil, Michele; Hess, Philipp; Amzil, Zouher. |
| beta-N-methylamino-L-alanine (BMAA) is a neurotoxic non-protein amino acid suggested to be involved in neurodegenerative diseases. It was reported to be produced by cyanobacteria, but also found in edible aquatic organisms, thus raising concern of a widespread human exposure. However, the chemical analysis of BMAA and its isomers are controversial, mainly due to the lack of selectivity of the analytical methods. Using factorial design, we have optimized the chromatographic separation of underivatized analogues by a hydrophilic interaction chromatography coupled to tandem mass spectrometry (HILIC-MS/MS) method. A combination of an effective solid phase extraction (SPE) clean-up, appropriate chromatographic resolution and the use of specific mass spectral... |
| Tipo: Text |
Palavras-chave: Cyanotoxins; BMAA; DAB; AEG; HILIC-MS/MS; Cyanobacteria; Bivalve mollusks; French Mediterranean. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00245/35579/34112.pdf |
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| Kerbrat, Anne Sophie; Amzil, Zouher; Pawlowiez, Ralph; Golubic, Stjepko; Sibat, Manoella; Darius, Helene Taiana; Chinain, Mireille; Laurent, Dominique. |
| Marine pelagic diazotrophic cyanobacteria of the genus Trichodesmium (Oscillatoriales) are widespread throughout the tropics and subtropics, and are particularly common in the waters of New Caledonia. Blooms of Trichodesmium are suspected to be a potential source of toxins in the ciguatera food chain and were previously reported to contain several types of paralyzing toxins. The toxicity of water-soluble extracts of Trichodesmium spp. were analyzed by mouse bioassay and Neuroblastoma assay and their toxic compounds characterized using liquid chromatography coupled with tandem mass spectrometry techniques. Here, we report the first identification of palytoxin and one of its derivatives, 42-hydroxy-palytoxin, in field samples of Trichodesmium collected in... |
| Tipo: Text |
Palavras-chave: Cyanobacteria; Trichodesmium; Palytoxin; 42-hydroxy-palytoxin; Clupeotoxism. |
| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00040/15143/12576.pdf |
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| Jauffrais, Thierry; Sechet, Veronique; Truquet, Philippe; Amzil, Zouher; Herrenknecht, Christine; Hess, Philipp. |
| Azadinium spinosum, a small dinoflagellate has recently been discovered and identified as the primary producer of azaspiracid-1 (AZA) and -2. Since AZA poisoning has been reported following consumption of contaminated shellfish it is important to have these toxins available for toxicological studies, and a sustainable production of AZAs as calibrants in monitoring programs without having to rely on natural events. In order to address this concern, continuous pilot scale cultures were carried out to evaluate the feasibility of AZA production from A. spinosum. Algae were cultured using two 100 L chemostats in series (R1 and R2), with agitation and pH control. Four different dilution rates were tested (0.15, 0.2, 0.25 and 0.3 day−1) to evaluate chemostat... |
| Tipo: Text |
Palavras-chave: Solid phase adsorption; Chemostat; Photobioreactor; Microalgae; LC-MS/MS; Tangential flow filtration. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00152/26349/24437.pdf |
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| Chapelle, Annie; Le Bec, Claude; Amzil, Zouher; Dreanno, Catherine; Guillou, Laure; Klouch, Khadidja; Labry, Claire; Le Gac, Mickael; Pineau-guillou, Lucia; Siano, Raffaele; Abernot, Chantal; Andrieux, Francoise; Caradec, Florian; Destombe, Christophe; Dia, A.; Doner, Anne; Duval, Julia; Gouriou, Jeremie; Lazure, Pascal; Le Brun, Luc; Le Gal, Dominique; Malestroit, Pascale; Petton, Sebastien; Plus, Martin; Quere, Julien; Savar, Veronique; Schmitt, Sophie; Terre, A.; Youenou, Agnes. |
| Suite à l’événement de grande ampleur d’efflorescence d’Alexandrium minutum et des toxicités associées en Rade de Brest en 2012, un projet a été élaboré avec la Région Bretagne dans le cadre du développement du port de Brest. L’Ifremer a organisé un échantillonnage dans l’estuaire de la rivière de Daoulas, zone la plus touchée en 2012, au cours des printemps-été 2013 et 2014. Un suivi de la présence d’A. minutum dans les sédiments a également été réalisé en hiver 2014. De ces suivis, des mesures réalisées au laboratoire à ce jour, des simulations du modèle Prévimer ainsi que des résultats du réseau Rephy et Velyger, il ressort que: * La rade de Brest peut aujourd’hui être considérée comme une zone à risque pour Alexandrium minutum. En effet, depuis 2012... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00254/36487/35029.pdf |
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| Darius, Helene Taiana; Roue, Melanie; Sibat, Manoella; Viallon, Jerome; Gatti, Clemence Mahana Iti; Vandersea, Mark W.; Tester, Patricia A.; Litaker, R. Wayne; Amzil, Zouher; Hess, Philipp; Chinain, Mireille. |
| Ciguatera fish poisoning (CFP) is a foodborne disease caused by the consumption of seafood (fish and marine invertebrates) contaminated with ciguatoxins (CTXs) produced by dinoflagellates in the genus Gambierdiscus. The report of a CFP-like mass-poisoning outbreak following the consumption of Tectus niloticus (Tegulidae, Gastropod) from Anaho Bay on Nuku Hiva Island (Marquesas archipelago, French Polynesia) prompted field investigations to assess the presence of CTXs in T. niloticus. Samples were collected from Anaho Bay, 1, 6 and 28 months after this poisoning outbreak, as well as in Taiohae and Taipivai bays. Toxicity analysis using the neuroblastoma cell-based assay (CBA-N2a) detected the presence of CTXs only in Anaho Bay T. niloticus samples. This is... |
| Tipo: Text |
Palavras-chave: Ciguatera poisoning; Ciguatoxins; Tectus niloticus; Gastropods; Gambierdiscus polynesiensis; QPCR assays; CBA-N2a; LC-MS; MS. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00426/53798/54719.pdf |
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| Medhioub, Amel; Medhioub, Walid; Amzil, Zouher; Sibat, Manoella; Bardouil, Michele; Ben Neila, Idriss; Mezghani, Salah; Hamza, Asma; Lassus, Patrick. |
| Karenia selliformis strain GM94GAB was isolated in 1994 from the north of Sfax, Gabes gulf, Tunisia. This species, which produces gymnodimine (GYM) a cyclic imine, has since been responsible for chronic contamination of Tunisian clams. A study was made by culturing the microalgae oil enriched Gaillard f/2 medium. The influence of growing conditions oil toxin content was studied, examining the effects of (i) different culture Volumes (0.25 to 40 litre flasks), (ii) two temperature ranges (17-15 degrees C et 20-21 degrees C) and (iii) two salinities (36 and 44). Chemical analyses were made by mass spectrometry coupled with liquid chromatography (LC-MS/MS). Results showed that (i) the highest growth rate (0.34 +/- 0.14 div d(-1)) was obtained at 20 degrees C... |
| Tipo: Text |
Palavras-chave: Mouse bioassay; Gymnodimine; Toxicity; Growth; Karenia selliformis. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7383.pdf |
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| Pisapia, Francesco; Holland, William C.; Hardison, D. Ransom; Litaker, R. Wayne; Fraga, Santiago; Nishimura, Tomohiro; Adachi, Masao; Lam Nguyen-ngoc,; Sechet, Veronique; Amzil, Zouher; Herrenknecht, Christine; Hess, Philipp. |
| Species in the epi-benthic dinoflagellate genus Gambierdiscus produce ciguatoxins (CTXs) and maitotoxins (MTXs), which are among the most potent marine toxins known. Consumption of fish contaminated with sufficient quantities of CTXs causes Ciguatera Fish Poisoning (CFP), the largest cause of non-bacterial food poisoning worldwide. Maitotoxins, which can be found in the digestive system of fish, could also contribute to CFP if such tissues are consumed. Recently, an increasing number of Gambierdiscus species have been identified; yet, little is known about the variation in toxicity among Gambierdiscus strains or species. This study is the first assessment of relative CTX- and MTX-toxicity of Gambierdiscus species from areas as widespread as the... |
| Tipo: Text |
Palavras-chave: Ciguatera fish poisoning; Gambierdiscus; Ciguatoxins; Maitotoxins; Neuro-2a assay; Erythrocyte lysis assay. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00374/48552/49411.pdf |
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| Belin, Catherine; Soudant, Dominique; Amzil, Zouher. |
| In France, REPHY (Observation and Surveillance Network for Phytoplankton and Hydrology in coastal waters) and REPHYTOX (Monitoring Network for Phycotoxins in marine organisms) have been contributing to long-term time series on ocean health for more than 30 years. The aim of this paper is to describe these networks and to highlight their key results. Over the last 20 years, phytoplankton flora analysis on French coasts from the Channel to Mediterranean has shown that the five “emblematic” taxa are Chaetoceros, Skeletonema, Cryptophyceae, Leptocylindrus and Pseudo-nitzschia. The latter, together with the taxa of interest Dinophysis + Phalacroma, Alexandrium, and Karenia, have been consistently recorded along the entire French coastline. However, when taking... |
| Tipo: Text |
Palavras-chave: Monitoring network; Phytoplankton time-series; Dominant species; DST-Diarrheic; Shellfish Toxins; PST-Paralytic Shellfish Toxins; AST-Amnesic Shellfish Toxins. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00617/72948/72699.pdf |
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| Medhioub, Walid; Ramondenc, Simon; Vanhove, Audrey; Vergnes, Agnes; Masseret, Estelle; Savar, Veronique; Amzil, Zouher; Laabir, Mohamed; Rolland, Jean-luc. |
| This study assessed the apoptotic process occurring in the hemocytes of the Pacific oyster, Crassostrea gigas, exposed to Alexandrium catenella, a paralytic shellfish toxins (PSTs) producer. Oysters were experimentally exposed during 48 h to the toxic algae. PSTs accumulation, the expression of 12 key apoptotic-related genes, as well as the variation of the number of hemocytes in apoptosis was measured at time intervals during the experiment. Results show a significant increase of the number of hemocytes in apoptosis after 29 h of exposure. Two pro-apoptotic genes (Bax and Bax-like) implicated in the mitochondrial pathway were significantly upregulated at 21 h followed by the overexpression of two caspase executor genes (caspase-3 and caspase-7) at 29 h,... |
| Tipo: Text |
Palavras-chave: Shellfish; Toxins; Apoptosis; Gene expression. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00176/28744/27213.pdf |
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| Belin, Catherine; Amzil, Zouher. |
| Toxin monitoring is carried out along the coasts of France by a national network, REPHY, which is the National Monitoring Network for Phytoplankton and Phycotoxins. Sampling strategy differs according to the type of zone coastal or offshore and to the family of toxins. For PSP and ASP toxins, monitoring is based on the detection of toxic phytoplankton species. For lipophilic toxins, a systematic analysis of toxins is performed in risk areas during high risk periods. Experimental monitoring for palytoxins has also been conducted along the Mediterranean coast since 2007. The total number of toxin analyses is in the order of 2500 to 3000 per year. The detailed results for each family of toxins showed that the most frequent toxic events for the period from... |
| Tipo: Text |
Palavras-chave: Monitoring; Phytoplankton; Toxin; Sampling; Shellfish; French coasts. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00077/18821/16398.pdf |
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| Brissard, Charline; Herve, Fabienne; Sibat, Manoella; Sechet, Veronique; Hess, Philipp; Amzil, Zouher; Herrenknecht, Christine. |
| The presence of Ostreopsis cf. ovata on the Mediterranean coast represents a serious concern to human health due to production of toxins–putative palytoxin and ovatoxins (ovatoxin-a, -b, -c, -d, -e, -f and -g). However, purified ovatoxins are not widely available and their toxicities are still unknown. In the present study, we report on HR LC-MS/MS analysis of a French Ostreopsis cf. ovata strain (IFR-OST-0.3 V) collected at Villefranche-sur-Mer (France) during a bloom in 2011. Investigation of this strain of Ostreopsis cf. ovata cultivated in our laboratory by ultra-high performance liquid chromatography coupled to high resolution mass spectrometry (UHPLC-HRMS) confirmed the production of ovatoxins -a to–e and revealed the presence of a new ovatoxin... |
| Tipo: Text |
Palavras-chave: Ostreopsis cf. ovata; Palytoxin; Ovatoxins; U-HPLC/HR-MSn; Chromatographic separation. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00252/36302/34831.pdf |
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| Roue, Melanie; Darius, Helene Taiana; Ung, Andre; Viallon, Jerome; Sibat, Manoella; Hess, Philipp; Amzil, Zouher; Chinain, Mireille. |
| Ciguatera is a foodborne disease caused by the consumption of seafood contaminated with ciguatoxins (CTXs). Ciguatera-like poisoning events involving giant clams (Tridacna maxima) are reported occasionally from Pacific islands communities. The present study aimed at providing insights into CTXs tissue distribution and detoxification rate in giant clams exposed to toxic cells of Gambierdiscus polynesiensis, in the framework of seafood safety assessment. In a first experiment, three groups of tissue (viscera, flesh and mantle) were dissected from exposed individuals, and analyzed for their toxicity using the neuroblastoma cell-based assay (CBA-N2a) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses. The viscera, flesh, and mantle were... |
| Tipo: Text |
Palavras-chave: Giant clams; Ex situ exposure to toxic algae; Ciguatoxins; Gambierdiscus polynesiensis; Anatomical distribution; Toxin elimination; CBA-N2a; LC-MS/MS. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00440/55123/56579.pdf |
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| Gueguen, Marielle; Lassus, Patrick; Laabir, Mohamed; Bardouil, Michele; Baron, Regis; Sechet, Veronique; Truquet, Philippe; Amzil, Zouher; Barille, Laurent. |
| The occurrence of new phytoplankton species in a coastal area may be explained by the import of shellfish containing whole live algal cells in their digestive tracts. Indeed, shellfish containing toxic algal cells can induce both primary contaminations in safe areas ( initially free from toxic microalgae), and secondary contaminations of other shellfish growing in the same area via the faeces of the imported animals. To mitigate this problem, shellfish need to be placed in a separate holding tank and their intestinal content purged. For a deeper understanding of the risks associated with transferring contaminated shellfish, oysters ( Crassostrea gigas) and mussels ( Mytilus edulis) were purposely fed either Alexandrium minutum or A. catenella (... |
| Tipo: Text |
Palavras-chave: Risk assessment; Toxic phytoplankton; Uptake; Gut passage; Mytilus edulis; Crassostrea gigas. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3897.pdf |
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| Darius, Helene Taiana; Roue, Melanie; Sibat, Manoella; Viallon, Jerome; Gatti, Clemence Mahana Iti; Vandersea, Mark W.; Tester, Patricia A.; Litaker, R. Wayne; Amzil, Zouher; Hess, Philipp; Chinain, Mireille. |
| The sea urchin Tripneustes gratilla (Toxopneustidae, Echinoids) is a source of protein for many islanders in the Indo-West Pacific. It was previously reported to occasionally cause ciguatera-like poisoning; however, the exact nature of the causative agent was not confirmed. In April and July 2015, ciguatera poisonings were reported following the consumption of T. gratilla in Anaho Bay (Nuku Hiva Island, Marquesas archipelago, French Polynesia). Patient symptomatology was recorded and sea urchin samples were collected from Anaho Bay in July 2015 and November 2016. Toxicity analysis using the neuroblastoma cell–based assay (CBA-N2a) detected the presence of ciguatoxins (CTXs) in T. gratilla samples. Gambierdiscus species were predominant in the benthic... |
| Tipo: Text |
Palavras-chave: Ciguatera poisoning; Ciguatoxins; Tripneustes gratilla; Sea urchin; Echinoidea; Gambierdiscus polynesiensis; Windowscreens; Artificial substrates; QPCR assays; CBA-N2a; LC-MS/MS. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00436/54716/56153.pdf |
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| Rolland, Jean-luc; Medhioub, Walid; Vergnes, Agnes; Abi-khalil, Celina; Savar, Veronique; Abadie, Eric; Masseret, Estelle; Amzil, Zouher; Laabir, Mohamed. |
| To better understand the effect of Paralytic Shellfish Toxins (PSTs) accumulation in the digestive gland of the Pacific oyster, Crassostrea gigas, we experimentally exposed individual oysters for 48 h to a PSTs producer, the dinoflagellate Alexandrium catenella. In comparison to the effect of the non-toxic Alexandrium tamarense, on the eight apoptotic related genes tested, Bax and BI.1 were significantly upregulated in oysters exposed 48 h to A. catenella. Among the five detoxification related genes tested, the expression of cytochrome P450 (CYP1A) was shown to be correlated with toxin concentration in the digestive gland of oysters exposed to the toxic dinoflagellate. Beside this, we observed a significant increase in ROS production, a decrease in... |
| Tipo: Text |
Palavras-chave: Shellfish; Toxin; Biomarker; Expression; Phytoplankton. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00225/33606/32003.pdf |
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| Amzil, Zouher; Royer, Florence; Sibat, Manoella; Fiant, Liliane; Gelin, Muriel; Le Gal, Dominique; Francoise, Sylvaine. |
| In the context of the French phytoplankton and phycotoxins monitoring network (REPHY), shellfish scallops were harvested systematically during the authorised fishing season for the purpose of investigating paralytic toxins (PSP-mouse test), amnesic toxins (ASPchemical analysis), and lipophilic toxins (DSP-mouse test). For all shellfish samples that tested positive in the DSP mouse bioassay used for lipophilic toxins detection, liquid chromatography coupled with mass spectrometry (LC-MS/MS) was used to search for the following lipophilic toxins: okadaic acid, dinophysistoxins, pectenotoxins, azaspiracids, yessotoxins, spirolides, and gymnodimine. In order to investigate the presence of okadaic acid esters (DTX3), alkaline hydrolysis was performed on all... |
| Tipo: Text |
Palavras-chave: Scallops; Domoic acid; Okadaic acid and derivatives; Dinophysis. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00015/12577/9447.pdf |
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| Registros recuperados: 83 | |
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