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| Registros recuperados: 83 | |
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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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| Mondeguer, Florence; Sibat, Manoella; Reubrecht, Sébastien; Amzil, Zouher; Bormans, Myriam; Hess, Philipp; Briand, Enora. |
| Cyanobacterial proliferation is one of the most harmful hazards, in both freshwater and marine ecosystems. Cyanobacteria are well known for their ability to produce a wide variety of bioactive compounds, some of which have been described as allelochemicals. There is growing evidence that these secondary metabolites play an important role in shaping community composition through biotic interactions; however, for the most part, their biological role and mode of regulation of the production are poorly understood. In temperate eutrophic freshwaters, Microcystis and Planktothrix often co-occur, with Planktothrix being an early colonizer and Microcystis appearing subsequently. By integrating LC-MS/MS molecular networking and an innovative experimental design, we... |
| Tipo: Text |
Palavras-chave: Cyanobacteria; Cyanotoxins; Plankton interactions; Co_culture; LC_HRMS; Molecular Network; Metabolomics. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00405/51666/52215.pdf |
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| Balti, Rafik; Brodu, Nicolas; Zhang, Jiaxuan; Amzil, Zouher; Drouin, Delphine; Sechet, Veronique; Masse, Anthony. |
| The Paralytic shellfish neurotoxins (PST) are of increasing interest for biomedical applications. The chemical synthesis is often complex and expensive that’s why the purification by membrane filtration of PST from Alexandrium minutum dinoflagellate was investigated. Disrupted micro-alga cells by ultrasonic treatment were diafiltred to let pass toxins through an ultrafiltration membrane. Then, the mean permeate was concentrated and diafiltrated by nanofiltration. Mean permeate fluxes equal to 187, 135 and 135 L.h–1.m-2 were obtained during the first diafiltration, the concentration step and the final diafiltration respectively. Up to 57 % (mol/mol) and 78 % (mol/mol) of organic matters and salts were removed respectively. Divalent ions were sparsely... |
| Tipo: Text |
Palavras-chave: Paralytic shellfish poisoning; Nanofiltration; Membrane; Alexandrium minutum; Purification. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00451/56286/57865.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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| Belin, Catherine; Marcaillou-le Baut, Claire; Amzil, Zouher; Ledoux, Martial. |
| This document describes and harmonizes detection methods of diarrheic (DSP) and paralytic (PSP) phycotoxins, for the laboratories of the Direction of Coastal Environment of IFREMER, which work in the framework of the French Phytoplankton and Phycotoxins Monitoring Network. These toxins, produced by a few phytoplankton species which regularly occur in sea water, accumulate in shellfish, which become toxic. Analysis is performed on an extract of digestive gland (DSP), or of total flesh (PSP), of shellfish. The described methods are meuse-tests, which are, at the present time, the only methods available to be used in the framework of a monitoring network. The method for diarrheic toxins is not standardized, with a threshold adapted for monitoring purposes. At... |
| Tipo: Text |
Palavras-chave: Phycotoxines; Méthode de détection des toxines; Test-souris; Toxines diarrhéïques; DSP; Toxines paralysantes; PSP; Surveillance; Phycotoxins; Toxin detection method; Mouse-test; Diarrheic toxins; DSP; Paralytic toxins; PSP; Monitoring. |
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00429/54106/55438.pdf |
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| Amzil, Zouher; Sibat, Manoella; Royer, Florence; Masson, Nadine; Abadie, Eric. |
| In the context of the French Phytoplankton and Phycotoxins Monitoring Network (REPHY) programme, shellfish samples were harvested from different locations where harmful algae blooms were known to have occurred. For all shellfish samples found positive by the mouse bioassay for diarrhetic shellfish poisoning (DSP) toxins, liquid chromatography (LC) coupled with mass spectrometry (MS) was used to search for the following lipophilic toxins: okadaic acid (OA), dinophysistoxins (DTXs), pectenotoxins (PTXs), azaspiracids (AZAs), yessotoxins (YTXs), spirolides (SPXs) and gymnodimines (GYMs). In order to investigate the presence of acyl-OAs and/or acyl-DTX-1,-2 (DTX-3), alkaline hydrolysis was performed on all samples, and LC/ MS analyses were carried out on the... |
| Tipo: Text |
Palavras-chave: LC/MS analysis; Pectenotoxins; Spirolides; DSP toxins. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-6206.pdf |
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| Georges Des Aulnois, Maxime; Réveillon, Damien; Robert, Elise; Caruana, Amandine; Briand, Enora; Guljamow, Arthur; Dittmann, Elke; Amzil, Zouher; Bormans, Myriam. |
| The transfer of Microcystis aeruginosa from freshwater to estuaries has been described worldwide and salinity is reported as the main factor controlling the expansion of M. aeruginosa to coastal environments. Analyzing the expression levels of targeted genes and employing both targeted and non-targeted metabolomic approaches, this study investigated the e ect of a sudden salt increase on the physiological and metabolic responses of two toxic M. aeruginosa strains separately isolated from fresh and brackish waters, respectively, PCC 7820 and 7806. Supported by di erences in gene expressions and metabolic profiles, salt tolerance was found to be strain specific. An increase in salinity decreased the growth of M. aeruginosa with a lesser impact on the... |
| Tipo: Text |
Palavras-chave: Microcystis aeruginosa; Microcystin; Salt stress; Metabolomic; Transcript. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00615/72689/71692.pdf |
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| Reveillon, Damien; Sechet, Veronique; Hess, Philipp; Amzil, Zouher. |
| The neurotoxin β-N-methylamino-L-alanine (BMAA) is naturally present in some microalgal species in the marine environment. The accumulation of BMAA has widely been observed in filter-feeding bivalves that are known to consume primary producers constituting the base of complex aquatic food webs. This study was performed to assess the occurrence of BMAA and isomers in mollusks collected from nine representative shellfish production areas located on the three French coasts (Channel, Atlantic and Mediterranean sites). The use of a highly selective and sensitive HILIC-MS/MS method, with D5DAB as internal standard, revealed the systematic detection of BMAA and DAB, in concentrations ranging from 0.20 to 6.7 μg g-1 dry weight of digestive gland tissues of... |
| Tipo: Text |
Palavras-chave: BMAA; Chaetoceros; Thalassiosira; Phaeodactylum; Bivalves; Seafood. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00297/40780/39784.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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| 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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| 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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| Amzil, Zouher; Marcaillou-le Baut, Claire; Bohec, Madeleine. |
| Depuis janvier 1993, des épisodes de forte toxicité des coquillages ont été observés lors des contrôles de routine en différents points des côtes françaises. Les souris ayant reçu des extraits de coquillages, par voie intrapéritonéale, présentaient des symptômes de type neurologique et mouraient au bout de 5 à 15 minutes. Cette toxicité n'a pu être attribuée à l'existence de phycotoxines connues. Les études préliminaires réalisées sur les glandes digestives de moules toxiques, récoltées lors d'un de ces épisodes (rade de Toulon), nous ont permis d'acquérir les données suivantes : le principe actif possède une forte polarité, il est thermostable, et il est stable dans le temps et en milieu acide. L'intoxication par voie orale chez la souris a permis de... |
| Tipo: Text |
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| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00075/18596/16149.pdf |
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| Ben-gharbia, Hela; Yahia, Ons Kefi-daly; Amzil, Zouher; Chomerat, Nicolas; Abadie, Eric; Masseret, Estelle; Sibat, Manoella; Triki, Habiba Zmerli; Nouri, Habiba; Laabir, Mohamed. |
| armful benthic dinoflagellates, usually developing in tropical areas, are expanding to temperate ecosystems facing water warming. Reports on harmful benthic species are particularly scarce in the Southern Mediterranean Sea. For the first time, three thermophilic benthic dinoflagellates (Ostreopsis cf. ovata, Prorocentrum lima and Coolia monotis) were isolated from Bizerte Bay (Tunisia, Mediterranean) and monoclonal cultures established. The ribotyping confirmed the morphological identification of the three species. Maximum growth rates were 0.59 ± 0.08 d−1 for O. cf. ovata, 0.35 ± 0.01 d−1 for C. monotis and 0.33 ± 0.04 d−1 for P. lima. Toxin analyses revealed the presence of ovatoxin-a and ovatoxin-b in O. cf. ovata cells. Okadaic acid and... |
| Tipo: Text |
Palavras-chave: Ostreopsis cf. ovata; Prorocentrum lima; Coolia monotis; Southern Mediterranean Sea; Growth; Toxicity. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00355/46585/46393.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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| 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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| Gémin, Marin-pierre; Réveillon, Damien; Hervé, Fabienne; Pavaux, Anne-sophie; Tharaud, Maxime; Séchet, Veronique; Bertrand, Samuel; Lemée, Rodolphe; Amzil, Zouher. |
| Over the last fifteen years, blooms of the genus Ostreopsis have been reported more frequently and at higher abundances in the Mediterranean area. Ostreopsis cf. ovata is known to produce ovatoxins (OVTXs), structural analogues of palytoxin, which is one of the most potent non-polymeric toxins. However, the production of OVTXs is poorly characterized in situ. The present study focuses on toxin content and profile according to the bloom phase during summer 2017 in Villefranche-sur-Mer, France (NW Mediterranean Sea), depth (from 0.5 to 5 m) and three different macroalgal substrates of this epiphytic dinoflagellate (Padina pavonica, Dictyota spp. and Halopteris scoparia). Ovatoxin quantification of all samples was performed by liquid chromatography coupled to... |
| Tipo: Text |
Palavras-chave: Dinoflagellate; Benthic HABs; Ostreopsis cf. ovata; Ovatoxins; Mediterranean Sea. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00614/72566/74835.pdf |
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| Amzil, Zouher; Motteau, Lydie. |
| Dans le cadre du réseau de surveillance français en matière de toxines amnésiantes, l'acide domoïque a été détecté pour la première fois dans des échantillons de coquillages. En effet, le dosage de lacide domoïque (AD) par Chromatographie Liquide Haute Performance couplée à un détecteur Ultra Violet (CLHP/UV), méthode officielle, dans la partie comestible des bivalves est effectué dès que le seuil de 105 cellules par litre de diatomée du genre Pseudo-nitzchia spp. est dépassé. Les analyses réalisées pendant l'année 1999 ont révélé la présence de l'acide domoïque dans des bivalves prélevés en différents points des côtes françaises. Toutefois, la quantité maximale de toxine trouvée ne dépassait pas 3,2 µg d'AD par g de chair totale de coquillages, ce qui est... |
| Tipo: Text |
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| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00104/21574/19154.pdf |
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| Registros recuperados: 83 | |
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