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| Registros recuperados: 83 | |
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| Zendong, Suzie Zita; Mccarron, Pearse; Herrenknecht, Christine; Sibat, Manoella; Amzil, Zouher; Cole, Richard B.; Hess, Philipp. |
| Measurement of marine algal toxins has traditionally focussed on shellfish monitoring while, over the last decade, passive sampling has been introduced as a complementary tool for exploratory studies. Since 2011, liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been adopted as the EU reference method (No.15/2011) for detection and quantitation of lipophilic toxins. Traditional LC-MS approaches have been based on low-resolution mass spectrometry (LRMS), however, advances in instrument platforms have led to a heightened interest in the use of high-resolution mass spectrometry (HRMS) for toxin detection. This work describes the use of HRMS in combination with passive sampling as a progressive approach to marine algal toxin surveys. Experiments... |
| Tipo: Text |
Palavras-chave: Monitoring; Marine toxins; Passive sampling; SPATT; Matrix effects. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00277/38848/37388.pdf |
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| Laabir, Mohamed; Collos, Yves; Masseret, Estelle; Grzebyk, Daniel; Abadie, Eric; Savar, Veronique; Sibat, Manoella; Amzil, Zouher. |
| Laboratory experiments were designed to study the toxin content and profile of the Alexandrium catenella strain ACT03 (isolated from Thau Lagoon, French Mediterranean) in response to abiotic environmental factors under nutrient-replete conditions. This dinoflagellate can produce various paralytic shellfish toxins with concentrations ranging from 2.9 to 50.3 fmol/cell. The toxin profile was characterized by carbamate toxins (GTX3, GTX4 and GTX5) and N-sulfocarbamoyl toxins (C1, C2, C3 and C4). C2 dominated at 12-18 degrees C, but only for salinities ranging from 10 to 25 psu, whereas GTX5 became dominant at temperatures ranging from 21 to 30 degrees C at almost all salinities. There was no significant variation in the cellular toxin amount from 18 degrees C... |
| Tipo: Text |
Palavras-chave: Alexandrium catenella; PSP toxins; Temperature; Salinity; Light. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00148/25969/24056.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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| Ayache, Nour; Hervé, Fabienne; Martin-jézéquel, Veronique; Amzil, Zouher; Caruana, Amandine. |
| Several coastal countries including France have experienced serious and increasing problems related to Pseudo‐nitzschia toxic blooms. These toxic blooms occur in estuarine and coastal waters potentially subject to fluctuations in salinity. In this study, we document for the first time the viability, growth, photosynthetic efficiency and toxin production of two strains of Pseudo‐nitzschia australis grown under conditions with sudden salinity changes. Following salinity variation, the two strains survived over a restricted salinity range of 30 to 35, with favorable physiological responses, as the growth, effective quantum yield and toxin content were high compared to the other conditions. In addition, high cellular quotas of domoic acid (DA) were observed at... |
| Tipo: Text |
Palavras-chave: Amnesic shellfish poisoning; Domoic acid; Harmful algae; Pseudo-nitzschia australis; Salinity stress. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00462/57385/59465.pdf |
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| Ben Haddouch, Asia; Amanhi, Rachid; Amzil, Zouher; Taleb, Hamib; Rovillon, Georges-augustin; Adly, Farida; Loutfi, Mohammed. |
| Forthe Moroccan Phycotoxins Monitoring that is part of theSafety of theCoastal Monitoring Network(RSSL),shellfish sampleswereharvestedfromdifferentlocations at NorthAtlantic of Morocco whereharmful algaeblooms were known to have occurred. Forallshellfishsamples found positive by themouse bioassay fordiarrheicshellfishpoisoning(DSP)toxins,liquid chromatography coupled to tandem massspectrometry(LC-MS-MS) in order to search thefollowinglipophilictoxins: okadaic acid (OA), dinophysistoxins(DTXs), pectenotoxins(PTXs), azaspiracids(AZAs), yessotoxins(YTXs), spirolides(SPXs) and gymnodimines (GYMs).Theresultsrevealeddifferentlipophilictoxinprofiles as a function of theshellfish sampling location. It has beennoticed that allthesamples contained OA and its... |
| Tipo: Text |
Palavras-chave: Diarrheictoxins; Lipophilic toxins; LC-MS/MS; Mouse test; Shellfish. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00372/48342/48495.pdf |
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| Lassus, Patrick; Amzil, Zouher; Bardouil, Michele; Baron, Regis; Bohec, Madeleine; Bougrier, Serge; Garen, Pierre; Laabir, Mohamed; Leguay, Didier; Masselin, Pierre; Truquet, Philippe; Sechet, Veronique; Bablon, Clotilde; Berard, Jean-baptiste; Carre, Camille; Cheignon, Valerie; Lecamp, Sylvain; Mabit, Marie. |
| L'objectif général de l'étude est de simuler les épisodes de contamination de certains bivalves (huîtres et moules) par les toxines d'Alexandrium minutum et A. calenella à partir d'un module expérimental adapté, et en vue de construire un modèle de contamination applicable à ces espèces. Ce modèle sera ensuite susceptible d'être couplé aux modèles biologiques locaux (estuaire de Penzé et étang de Thau) de déterminisme des blooms, ainsi qu'aux modèles hydrodynamiques développés par différentes équipes (Ifremer, Université de Montpellier). La première année (2001-2002) était consacrée à la simulation des contaminations en estuaire de Penzé (Alexandrium minulum) et au développement de cultures en masse d'A. calenella de Thau en bioréacteurs. |
| Tipo: Text |
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| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/00156/26711/24786.pdf |
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| Gueguen, Marielle; Baron, Regis; Bardouil, Michele; Truquet, Philippe; Haberkorn, Hansy; Lassus, Patrick; Barille, Laurent; Amzil, Zouher. |
| The aim of this study was to evaluate the importance of biotransformation of paralytic shellfish toxins during the detoxification process in contaminated oysters. Mathematical models based upon the detoxification patterns of digestive gland and other tissues were developed. It was demonstrated that biotransformations do not seem to play an important role in digestive gland or other tissue detoxification kinetics with our data set. Moreover, different toxin transfers from digestive gland toward other tissues were investigated. No significant transfer was highlighted in our data set. These first conclusions were drawn after comparing the results obtained from 13 biotransformations and identifiable transfer scenarios. Finally, to determine a more robust... |
| Tipo: Text |
Palavras-chave: Detoxification kinetics modelling; Biotransformation of saxitoxin analogues; Oyster. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00049/16047/14309.pdf |
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| Pousse, Emilien; Flye-sainte-marie, Jonathan; Alunno-bruscia, Marianne; Hegaret, Helene; Rannou, Eric; Pecquerie, Laure; Marques, Goncalo M.; Thomas, Yoann; Castrec, Justine; Fabioux, Caroline; Long, Marc; Lassudrie, Malwenn; Hermabessiere, Ludovic; Amzil, Zouher; Soudant, Philippe; Jean, Fred. |
| As other filter-feeders, Crassostrea gigas can concentrate paralytic shellfish toxins (PST) by consuming dinoflagellate phytoplankton species like Alexandrium minutum. Intake of PST in oyster tissues mainly results from feeding processes, i.e. clearance rate, pre-ingestive sorting and ingestion that are directly influenced by environmental conditions (trophic sources, temperature). This study aimed to develop a mechanistic model coupling the kinetics of PST accumulation and bioenergetics in C. gigas based on Dynamic Energy Budget (DEB) theory. For the first time, the Synthesizing Units (SU) concept was applied to formalize the feeding preference of oysters between non-toxic and toxic microalgae. Toxin intake and accumulation were both dependent on the... |
| Tipo: Text |
Palavras-chave: Alexandrium minutum; Paralytic shellfish toxins (PST); Dynamic Energy Budget (DEB); Modelling; Pacific oyster. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00455/56662/58407.pdf |
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| Lassus, Patrick; Amzil, Zouher; Baron, Regis; Sechet, Veronique; Barille, Laurent; Abadie, Eric; Bardouil, Michele; Sibat, Manoella; Truquet, Philippe; Berard, Jean-baptiste; Gueguen, Marielle. |
| In October and November 2003 a bloom of the toxic dinoflagellate Alexandrium catenella was observed in the North-east zone of Thau lagoon (French Mediterranean coast). Sea water samples were collected every hours to evaluate time-related variations of phytoplankton concentrations and to compare the relative ratio of A. catenella versus other phytoplankton species during the outbreak. From these observations, trials using recirculated sea water systems were performed to: i) evaluate the physiological effects on oyster of increasing proportions of A. catenella within a mixed microalgal diet where the non-toxic diatom Thalassiosira weissflogii was present at concentration: 1500 cells ml(-1), ii) compare the effect of two temperatures (12 degrees C and 18... |
| Tipo: Text |
Palavras-chave: Mediterranean Sea; Alexandrium catenella; Toxin content; Model; Crassostrea gigas; Paralytic shellfish poisoning. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2624.pdf |
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| Boullot, Floriane; Castrec, Justine; Bidault, Adeline; Dantas, Natanael; Payton, Laura; Perrigault, Mickael; Tran, Damien; Amzil, Zouher; Boudry, Pierre; Soudant, Philippe; Hegaret, Helene; Fabioux, Caroline. |
| Paralytic shellfish toxins (PST) bind to voltage-gated sodium channels (Nav) and block conduction of action potential in excitable cells. This study aimed to (i) characterize Nav sequences in Crassostrea gigas and (ii) investigate a putative relation between Nav and PST-bioaccumulation in oysters. The phylogenetic analysis highlighted two types of Nav in C. gigas: a Nav1 (CgNav1) and a Nav2 (CgNav2) with sequence properties of sodium-selective and sodium/calcium-selective channels, respectively. Three alternative splice transcripts of CgNav1 named A, B and C, were characterized. The expression of CgNav1, analyzed by in situ hybridization, is specific to nervous cells and to structures corresponding to neuromuscular junctions. Real-time PCR analyses showed... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Sodium channel; Alternative splicing; Alexandrium minutum; Paralytic shellfish toxins. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00368/47877/47892.pdf |
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| Ben Gharbia, Hela; Yahia, Ons Kefi-daly; Cecchi, Philippe; Masseret, Estelle; Amzil, Zouher; Herve, Fabienne; Rovillon, Georges-augustin; Nouri, Habiba; M'Rabet, Charaf; Couet, Douglas; Triki, Habiba Zmerli; Laabir, Mohamed. |
| Macrophytes are known to release allelochemicals that have the ability to inhibit the proliferation of their competitors. Here, we investigated the effects of the fresh leaves of two magnoliophytes (Zostera noltei and Cymodocea nodosa) and thalli of the macroalgae Ulva rigida on three HAB-forming benthic dinoflagellates (Ostreopsis cf. ovata, Prorocentrum lima, and Coolia monotis). The effects of C. nodosa and U. rigida were also tested against the neurotoxic planktonic dinoflagellate Alexandrium pacificum Litaker sp. nov (former Alexandrium catenella). Co-culture experiments were conducted under controlled laboratory conditions and potential allelopathic effects of the macrophytes on the growth, photosynthesis and toxin production of the targeted... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00411/52200/52917.pdf |
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| Chomérat, Nicolas; Bilien, Gwenael; Derrien, Amelie; Henry, Kévin; Ung, André; Viallon, Jérôme; Darius, Hélène Taiana; Mahana Iti Gatti, Clémence; Roué, Mélanie; Hervé, Fabienne; Réveillon, Damien; Amzil, Zouher; Chinain, Mireille. |
| To date, the genus Ostreopsis comprises eleven described species, of which seven are toxigenic and produce various compounds presenting a major threat to human and environmental health. The taxonomy of several of these species however remains controversial, as it was based mostly on morphological descriptions leading, in some cases, to ambiguous interpretations and even possible misidentifications. The species Ostreopsis lenticularis was first described by Y. Fukuyo from French Polynesia using light microscopy observations, but without genetic information associated. The present study aims at revisiting the morphology, molecular phylogeny and toxicity of O. lenticularis based on the analysis of 47 strains isolated from 4 distinct locales of French... |
| Tipo: Text |
Palavras-chave: ITS-5.8S rDNA; LSU rDNA; Microscopy; Ostreopsis lenticularis; Taxonomy; Toxins. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00486/59747/62887.pdf |
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| Amzil, Zouher; Sibat, Manoella; Chomerat, Nicolas; Grossel, Hubert; Marco-miralles, Francoise; Lemee, Rodolphe; Nezan, Elisabeth; Sechet, Veronique. |
| Dinoflagellates of the genus Ostreopsis are known to cause (often fatal) food poisoning in tropical coastal areas following the accumulation of palytoxin (PLTX) and/or its analogues (PLTX group) in crabs, sea urchins or fish. Ostreopsis spp. occurrence is presently increasing in the northern to north western Mediterranean Sea (Italy, Spain, Greece and France), probably in response to climate change. In France, Ostreopsis. cf. ovata has been associated with toxic events during summer 2006, at Morgiret, off the coast of Marseille, and a specific monitoring has been designed and implemented since 2007. Results from 2008 and 2009 showed that there is a real danger of human poisoning, as these demonstrated bioaccumulation of the PLTX group (PLTX and ovatoxin-a)... |
| Tipo: Text |
Palavras-chave: Ostreopsis cf. ovata; Palytoxin; Ovatoxin-a; LC-MS/MS; Seafood. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00071/18230/15799.pdf |
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| Rolland, Jean-luc; Pelletier, Kevin; Masseret, Estelle; Rieuvilleneuve, Fabien; Savar, Veronique; Santini, Adrien; Amzil, Zouher. |
| The pacific oyster Crassostrea gigas was experimentally exposed to the neurotoxic Alexandrium catenella and a non-producer of PSTs, Alexandrium tamarense (control algae), at concentrations corresponding to those observed during the blooming period. At fixed time intervals, from 0 to 48 h, we determined the clearance rate, the total filtered cells, the composition of the fecal ribbons, the profile of the PSP toxins and the variation of the expression of two a-amylase and triacylglecerol lipase precursor (TLP) genes through semi-quantitative RT-PCR. The results showed a significant decrease of the clearance rate of C. gigas fed with both Alexandrium species. However, from 29 to 48 h, the clearance rate and cell filtration activity increased only in oysters... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Alexandrium catenella; PSP toxins; Digestion; Gene expression. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00130/24170/22172.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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| Georges Des Aulnois, Maxime; Roux, Pauline; Caruana, Amandine; Réveillon, Damien; Briand, Enora; Hervé, Fabienne; Savar, Veronique; Bormans, Myriam; Amzil, Zouher; Atomi, Haruyuki. |
| Proliferation of microcystin (MC)-producing Microcystis aeruginosa in brackish waters has been described in several locations and represents a new concern for public and environmental health. While the impact of a sudden salinity increase on M. aeruginosa physiology has been studied, less is known about the mechanisms involved in salt tolerance after acclimation. This study aims to compare the physiological responses of two strains of M. aeruginosa (PCC 7820 and PCC 7806), which were isolated from contrasted environments, to increasing salinities. After acclimation, growth and MC production rates were determined and metabolomic analyses were conducted. For both strains, salinity decreased the biovolume, growth, and MC production rates and induced the... |
| Tipo: Text |
Palavras-chave: Acclimation; Metabolomic; Microcystis; Salinity; Sucrose; Trehalose; Ecophysiology. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00588/70031/68012.pdf |
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| Hess, Philipp; Abadie, Eric; Herve, Fabienne; Berteaux, Tom; Sechet, Veronique; Araoz, Romulo; Molgo, Jordi; Zakarian, Armen; Sibat, Manoella; Rundberget, Thomas; Miles, Christopher O.; Amzil, Zouher. |
| Following a review of official control data on shellfish in France, Ingril Lagoon had been identified as a site where positive mouse bioassays for lipophilic toxins had been repeatedly observed. These unexplained mouse bioassays, also called atypical toxicity, coincided with an absence of regulated toxins and rapid death times in mice observed in the assay. The present study describes pinnatoxin G as the main compound responsible for the toxicity observed using the mouse bioassay for lipophilic toxins. Using a well-characterised standard for pinnatoxin G, LC-MS/MS analysis of mussel samples collected from 2009 to 2012 revealed regular occurrences of pinnatoxin G at levels sufficient to account for the toxicity in the mouse bioassays. Baseline levels of... |
| Tipo: Text |
Palavras-chave: Cyclic imines; Shellfish toxin; Accumulation; Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS); Unexplained mouse toxicity. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00158/26960/25255.pdf |
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| Hess, Philipp; Herve, Fabienne; Abadie, Eric; Sechet, Veronique; Molgo, Jordi; Amzil, Zouher; Fessard, Valerie. |
| Suite à la découverte de la Pinnatoxine G comme agent responsable des toxicités atypiques à Ingril fin 2010, une étude a été commanditée afin d’approfondir les connaissances sur l’organisme producteur de cette toxine, Vulcanodinium rugosum, les toxines associées et leur toxicité. L’organisme, étant considéré « cryptique » dû à sa faible présence dans le milieu, a été suivi de manière plus proche à Ingril. Il est apparu dans la colonne d’eau en juillet et août 2012, et quelques échantillons ont pu être prélevés pour la mise en culture de souches supplémentaires. Une corrélation directe entre la croissance de l’organisme et la température est soupçonnée mais n’a pas encore pu être corroborée sur la période d’étude, faute d’un nombre suffisant... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00094/20518/18190.pdf |
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| Registros recuperados: 83 | |
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