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| Registros recuperados: 37 | |
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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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| 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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| 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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| 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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| 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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| Sechet, Veronique; Quilliam, Michael; Lassus, Patrick. |
| L'hypothèse de la toxinogénèse bactérienne autonome dans le cadre des efflorescences marines toxiques de type DSP a été examinée. 18 souches bactériennes isolées à partir de culture de Prorocentrum lima et 12 souches obtenues à partir de prélèvements dans le milieu marin de Dinophysis sacculus (Baie de Vilaine) et de D. acuminata (Concarneau) ont été cultivées en milieu liquide, milieu de Shiba, pauvre en phosphore inorganique. La nouvelle espèce de bactérie présumée toxique, Roseobacter algicola, isolée préalablement à partir de P. lima, au laboratoire "Phycotoxines et Nuisances", a également été testée. Après extraction méthanolique et prépurification sur cartouches de silice, les résidus ont été estérifiés par le 9-antryldiazométhane afin d'être dosés... |
| Tipo: Text |
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| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00104/21575/19155.pdf |
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| Jauffrais, Thierry; Contreras, Andrea; Herrenknecht, Christine; Truquet, Philippe; Sechet, Veronique; Tillmann, Urban; Hess, Philipp. |
| Azadinium spinosum, a small toxic dinoflagellate, was recently isolated and identified as a primary producer of azaspiracid toxins (AZAs). Previous experiments related to AZA accumulation in blue mussels upon direct feeding with A. spinosum revealed increased mussel mortality and had negative effects on the thickness of the digestive gland tubules. Therefore we conducted follow up experiments in order to study effects of A. spinosum on mussel feeding behaviour. Individual assessment of mussel feeding time activity (FTA), clearance rate (CR), filtration rate (TFR), absorption rate (AR), faeces and pseudofaeces production were carried out on mussel fed either toxic (A. spinosum) or non-toxic (Isochrisis aff. galbana (T-Iso)) diets. Furthermore, AZA... |
| Tipo: Text |
Palavras-chave: Bivalve molluscs; Mussel; Ecophysiology; AZA biotransformation; AZA accumulation; Trophic transfer; Dinoflagellate; Azaspiracid. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00090/20174/17832.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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| Martin-jezequel, Veronique; Calu, Guillaume; Candela, Leo; Amzil, Zouher; Jauffrais, Thierry; Sechet, Veronique; Weigel, Pierre. |
| Over the last century, human activities have altered the global nitrogen cycle, and anthropogenic inputs of both inorganic and organic nitrogen species have increased around the world, causing significant changes to the functioning of aquatic ecosystems. The increasing frequency of Pseudo-nitzschia spp. in estuarine and coastal waters reinforces the need to understand better the environmental control of its growth and domoic acid (DA) production. Here, we document Pseudo-nitzschia spp. growth and toxicity on a large set of inorganic and organic nitrogen (nitrate, ammonium, urea, glutamate, glutamine, arginine and taurine). Our study focused on two species isolated from European coastal waters: P. multiseries CCL70 and P. australis PNC1. The nitrogen... |
| Tipo: Text |
Palavras-chave: Pseudo-nitzschia; Toxic diatoms; Nitrogen; Amino acids; Domoic acid. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00308/41912/41188.pdf |
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| Mondeguer, Florence; Abadie, Eric; Herve, Fabienne; Bardouil, Michele; Sechet, Veronique; Raimbault, Virginie; Berteaux, Tom; Zendong, Suzie Zita; Palvadeau, Hubert; Amzil, Zouher; Hess, Philipp; Fessard, Valérie; Huguet, Antoine; Sosa, Silvio; Tubaro, Aurelia; Aráoz, Rómulo; Molgó, Jordi. |
| Pour tenter d’apporter des réponses aux questions soulevées par une précédente étude commanditée pour approfondir les connaissances sur Vulcanodinium rugosum, l’organisme producteur de la Pinnatoxine G (PnTX G) (Hess et al., 2012), les objectifs de cette nouvelle étude sont les suivants : - Elargissement de la zone initiale de prélèvement d’Ingril à toute la lagune méditerranéenne et mise à profit de l’augmentation du nombre d’échantillons pour vérifier l’impact de l’effet matrice dans l’analyse LC-SM/MS. - Mise en culture en masse de Vulcanodinium rugosum et - Conduite d’une expérience de contamination in vivo sur des moules pour vérifier l’accumulation de la PnTX-G et comprendre les mécanismes de la métabolisation des PnTXs et de ses composés associés..... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00285/39635/38126.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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| Jauffrais, Thierry; Marcaillou-le Baut, Claire; Herrenknecht, Christine; Truquet, Philippe; Sechet, Veronique; Nicolau, Elodie; Tillmann, Urban; Hess, Philipp. |
| Azadinium spinosum (Elbrächter and Tillmann), a small marine dinoflagellate, has been recently described as a de novo producer of azaspiracid-1 and -2 (AZA1 and -2) diarrhoeic toxins. A culture of A. spinosum was established in our laboratory and optimised for pilot-scale production of this organism, to evaluate and understand AZA1 and -2 accumulation and biotransformation in blue mussels (Mytilus edulis) fed with A. spinosum. Adult mussels were continuously exposed to A. spinosum over 1 week in 160 L cylindrical conical tanks. Three different diets were tested for contamination: 5000, 10 000 cells mL−1 of A. spinosum and a mixture of 5000 cells mL−1 of A. spinosum with 5000 cells mL−1 of Isochrysis aff. galbana (T-Iso, CCAP 927/14). During the subsequent... |
| Tipo: Text |
Palavras-chave: Azaspiracid; Azadinium spinosum; Marine biotoxins; AZA; Tissue distribution; Histology; Bivalve molluscs; Liquid chromatography coupled to tandem mass spectrometry. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00088/19877/17566.pdf |
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| Abadie, Eric; Kaci, Lamia; Berteaux, Tom; Hess, Philipp; Sechet, Veronique; Masseret, Estelle; Rolland, Jean-luc; Laabir, Mohamed. |
| ulcanodinium rugosum, a recently described dinoflagellate species producing a potent neurotoxin (pinnatoxin G), has been identified in French Mediterranean lagoons and was responsible for recurrent episodes of shellfish toxicity detected by mouse bioassay. Until now, the biology and physiology of V. rugosum have not been fully investigated. We studied the growth characteristics and toxicity of a V. rugosum strain (IFR-VRU-01), isolated in the Ingril lagoon in June 2009 (North-Western French Mediterranean Sea). It was cultivated in Enriched Natural Sea Water (ENSW) with organic (urea) and inorganic (ammonium and nitrate) nitrogen, at a temperature of 25 °C and irradiance of 100 μmol/m2·s−1. Results showed that ammonium was assimilated by cells more rapidly... |
| Tipo: Text |
Palavras-chave: Vulcanodinium rugosum; Pinnatoxin G; Ingril lagoon; Growth; Nitrogen source. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00276/38748/37290.pdf |
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| Hess, Philipp; Geiger, Marie; Brochard, Solène; Lepretre, Thomas; Fessard, Valerie; Antignac, Jean-philippe; Dupont, Jacques; Sechet, Veronique; Vanel, Faustine; Mondeguer, Florence; Herve, Fabienne; Leborgne, Sabrina; Deslanglois, Gwenaëlle; Marshall, Lindsey; Rounds, Lucy; Guitton, Yann; Amzil, Zouher; Grovel, Olivier; Ruiz, Nicolas; Pouchus, Francois. |
| Cette étude s’est inscrite dans un contexte d’évaluation de la salubrité des mollusques bivalves destinés à la consommation humaine. Ces organismes peuvent en effet accumuler des toxines, en particulier de microalgues, en concentrations importantes, pouvant induire des intoxications chez les personnes les consommant. Afin d’assurer la protection des consommateurs, les toxines réglementées sont recherchées dans les coquillages par techniques physico-chimiques. En parallèle, les toxines émergentes, potentiellement produites par d’autres organismes que les micro-algues telles que les micromycètes, peuvent être detectées par l’utilisation du test de toxicité aigüe sur souris. Cependant, ce bio-essai présente de très nombreux inconvénients, notamment éthiques... |
| Tipo: Text |
Palavras-chave: Cytotoxicité; Toxicité sur larves de diptères; Activité antibactérienne; Bactéries marines; Toxines lipophiles; Micro-algues; Dinoflagellés; Micromycètes; Penicillium; Acide okadaïque; Azaspiracide; Pinnatoxine G; Vulcanodinium rugosum; Prorocentrum lima; Azadinium spinosum; Beauveria brongniartii. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00253/36470/35015.pdf |
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| Jauffrais, Thierry; Herrenknecht, Christine; Sechet, Veronique; Sibat, Manoella; Tillmann, Urban; Krock, Bernd; Kilcoyne, Jane; Miles, Christopher O.; Mccarron, Pearse; Amzil, Zouher; Hess, Philipp. |
| Azaspiracids (AZAs) are secondary metabolites of Azadinium spinosum, that have been shown to cause diarrhetic shellfish poisoning when accumulated in bivalve molluscs. We describe here an analytical procedure for the determination of AZAs in cultures of A. spinosum with a focus on the potential formation of AZA methyl-esters as artefacts in the extraction and sample pre-treatment. A. spinosum cells were collected from bioreactor cultures, using centrifugation or filtration. Different extraction procedures were evaluated for formation of methyl-ester artefacts, yield, and matrix effects. Filtration of cultures using glass-fibre filters led to increased formation of methyl-esters. Hence centrifugation is recommended for recovery of cells. The type of... |
| Tipo: Text |
Palavras-chave: Extraction procedure; Extraction artefact; Matrix effects; LC-MS/MS; Azaspiracid methyl ester; Dinoflagellate; Liquid chromatography-mass spectrometry. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00077/18812/16463.pdf |
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| Jauffrais, Thierry; Kilcoyne, Jane; Sechet, Veronique; Herrenknecht, Christine; Truquet, Philippe; Herve, Fabienne; Berard, Jean-baptiste; Nulty, Ciara; Taylor, Sarah; Tillmann, Urban; Miles, Christopher O.; Hess, Philipp. |
| Azaspiracid (AZA) poisoning has been reported following consumption of contaminated shellfish, and is of human health concern. Hence, it is important to have sustainable amounts of the causative toxins available for toxicological studies and for instrument calibration in monitoring programs, without having to rely on natural toxin events. Continuous pilot scale culturing was carried out to evaluate the feasibility of AZA production using Azadinium spinosum cultures. Algae were harvested using tangential flow filtration or continuous centrifugation. AZAs were extracted using solid phase extraction (SPE) procedures, and subsequently purified. When coupling two stirred photobioreactors in series, cell concentrations reached 190,000 and 210,000 cell·mL−1 at... |
| Tipo: Text |
Palavras-chave: Solid phase extraction; Photobioreactor; Chemostat; Dinoflagellate; Micro-algae; LC-MS/MS; Tangential flow filtration; Azaspiracid; HP-20. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00088/19875/17526.pdf |
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| Registros recuperados: 37 | |
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