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Acclimation of the marine diatom Pseudo‐nitzschia australis to different salinity conditions: effects on growth, photosynthetic activity and domoic acid content ArchiMer
Ayache, Nour; Hervé, Fabienne; Lundholm, Nina; Amzil, Zouher; Caruana, Amandine.
oxic Pseudo‐nitzschia australis strains isolated from French coastal waters were studied to investigate their capacity to adapt to different salinities. Their acclimation to different salinity conditions (10, 20, 30, 35 and 40) was studied on growth, photosynthetic capacity, cell biovolume and domoic acid (DA) content. The strains showed ability to acclimate to a salinity range from 20 to 40, with optimal growth rates between salinities 30 and 40. The highest cell biovolume was observed at the lowest salinity 20 and was associated with the lowest growth rate. Salinity did not affect the photosynthetic activity; Fv/Fm values and the pigment contents remained high with no significant difference among salinities. An enhanced production of zeaxanthin was,...
Tipo: Text Palavras-chave: Acclimation; Climate change; Domoic acid; Pseudo-nitzschia australis; Physiology; Salinity.
Ano: 2020 URL: https://archimer.ifremer.fr/doc/00585/69684/67552.pdf
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Détection de l'acide okadaïque dans les moules toxiques : comparaisons de bioéssais ArchiMer
Marcaillou-le Baut, Claire; Masselin, Pierre; Bohec, Madeleine; Truquet, Philippe; Amzil, Zouher; Pouchus, Francois; Le Boterff, Jean; Verbist, Jean-françois; Vernoux, Jean-paul; Marais, Chantal; Simon, Jean-françois; Nizard, Gabrielle; Mercier, Géraldine; Choumiloff, Roxelan; Baron, Bruno.
Cette étude est le résultat d'un travail de trois équipes: elle porte sur la comparaison du test souris avec différents bioessais déjà pratiqués en routine dans les laboratoires participants. Ces bioessais sont : - un test sur micro crustacé dont la méthodologie est normalisée et qui est très utilisé en écotoxicologie aquatique ; - un test de cytotoxicité à court terme qui a été mis au point pour cette étude.
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Ano: 1992 URL: http://archimer.ifremer.fr/doc/00139/25035/23144.pdf
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Cyanobactéries dans le Lac d’Hossegor en 2013 ArchiMer
Rumebe, Myriam; Auby, Isabelle; Chomerat, Nicolas; Amzil, Zouher; Costa, Magali; Arrue, François.
Cette note concerne une efflorescence de cyanobactéries du genre Planktothrix dans le Lac marin d'Hossegor, en janvier 2013. La provenance de ces microalgues a été identifiée et leur innocuité démontrée grâce aux résultats d'analyses des phycotoxines.
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Ano: 2013 URL: http://archimer.ifremer.fr/doc/00167/27834/26040.pdf
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Cytodétection des phycotoxines diarrhéiques - Une alternative au test de toxicité aiguë sur souris pour la surveillance de la salubrité des coquillages ArchiMer
Amzil, Zouher.
The cytodetection test of diarrheic phycotoxin KB-cells (DRAME test) was developed to ultimately provide a substitute for the acute toxicity mouse-test currently used by IFREMER's phytoplankton monitoring network (REPHY). The cyctodetection test relies on the cell morphological changes induced by the phosphorylation of cytoskeleton proteins resulting from the inhibition of cell protein-phosphatases by okadaic-type toxins. The method is specific, sensitive and fast with results given on the same day. In addition, the method has been shown to produce a good correlation with the acute toxicity mouse-test as weil as with HPLC analyses of diarrheic phycotoxins. The cytodetection test was awarded the only Special Prize of the Jury at the 6th AMAL THEE Awards...
Tipo: Text Palavras-chave: Acide okadaïque; Inhibition des protéines phosphatases; Cytodétection; Cellules KB; Okadaic acid; Inhibition of protein-phosphatase; Cytodeteciton KB-cells.
Ano: 1996 URL: http://archimer.ifremer.fr/doc/00156/26730/24811.pdf
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Chemically mediated interactions between Microcystis and Planktothrix: Impact on their physiology and metabolic profiles ArchiMer
Briand, Enora; Reubrech, Sébastien; Mondeguer, Florence; Sibat, Manoella; Hess, Philipp; Amzil, Zouher; Bormans, Myriam.
Freshwater 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. We tested if the production of a range of peptides by co-existing species could be regulated through interspecific interactions. Using a combined approach of co-cultures and analyses...
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Ano: 2017 URL: http://archimer.ifremer.fr/doc/00374/48515/48794.pdf
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COLNACOQ. Composés lipophiles naturels dans l’environnement des coquillages. Rapport final ArchiMer
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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Projet de recherche sur l'identification de nouveaux composés toxiques dans les coquillages ArchiMer
Amzil, Zouher.
ln November 1992, an event affecting Shellfish health received extensive media coverage: an unknown toxin had been detected in oysters from the bay of MarennesOleron (France). This phenomenon remains unexplained to this day. Since then, a growing number of observations obtained in the context of the REPHY phytoplankton monitoring network, have reported a mouse-active substance found in Shellfish and belonging to none of the known phycotoxin classes. These observations have been reported in France as weil as abroad (Canada, Norway, Ireland, New Zealand ... ). Mice treated intraperitoneally with the DSP screening test- exhibit neurological symptoms with disorders of the central nervous system leading to early death (within 5 to 10 minutes). Several hundred...
Tipo: Text Palavras-chave: Toxicité atypique; Test-souris; Neurotoxicité; Identification de principe(s) actif(s); Atypical toxicity; Mouse-test; Neurotoxicity; Identification of active principle( s).
Ano: 1996 URL: http://archimer.ifremer.fr/doc/00156/26732/24813.pdf
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Quantitative analysis of azaspiracids in Azadinium spinosum cultures ArchiMer
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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Surveillance des toxines lipophiles dans les coquillages. Ananlyse statistique et comparaison des résultats obtenus par deux méthodes d'analyse : les bio-essais sur souris et les analyses chimiques par CL-SM/SM ArchiMer
Belin, Catherine; Soudant, Dominique; Amzil, Zouher.
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Ano: 2009 URL: http://archimer.ifremer.fr/doc/00014/12568/9438.pdf
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Pre-purification by membrane filtration of paralytic shellfish toxins from Alexandrium minutum dinoflagellate ArchiMer
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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Systematic detection of BMAA (β-N-methylamino-L-alanine) and DAB (2,4-diaminobutyric acid) in mollusks collected in shellfish production areas along the French coasts ArchiMer
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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Report on the first detection of pectenotoxin-2, spirolide-A and their derivatives in French shellfish ArchiMer
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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Alexandrium ostenfeldii growth and spirolide production in batch culture and photobioreactor ArchiMer
Medhioub, Walid; Sechet, Veronique; Truquet, Philippe; Bardouil, Michele; Amzil, Zouher; Lassus, Patrick; Soudant, Philippe.
Growth and spirolide production of the toxic dinoflagellate Alexandrium ostenfeldii (Danish strain CCMP1773) were studied in batch culture and a photobioreactor (continuous cultures). First, batch cultures were grown in 450 mL flasks without aeration and under varying conditions of temperature (16 and 22 degrees C) and culture medium (L1, f/2 and L1 with addition of soil extract). Second, cultures were grown at 16 degrees C in 8 L aerated flat-bottomed vessels using L1 with soil extract as culture medium. Finally, continuous cultures in a photobioreactor were conducted at 18 degrees C in L1 with soil extract; pH was maintained at 8.5 and continuous stirring was applied. This study showed that A. ostenfeldii growth was significantly affected by temperature....
Tipo: Text Palavras-chave: Alexandrium ostenfeldii; Batch; Growth; Photobioreactor; Spirolide production.
Ano: 2011 URL: http://archimer.ifremer.fr/doc/00049/16050/15784.pdf
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Influence of sudden salinity variation on the physiology and domoic acid production by two strains of Pseudo-nitzschia australis ArchiMer
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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Complex Toxin Profile of French Mediterranean Ostreopsis cf. ovata Strains, Seafood Accumulation and Ovatoxins Prepurification ArchiMer
Brissard, Charline; Herrenknecht, Christine; Sechet, Veronique; Herve, Fabienne; Pisapia, Francesco; Harcouet, Jocelyn; Lemee, Rodolphe; Chomerat, Nicolas; Hess, Philipp; Amzil, Zouher.
Ostreopsis cf. ovata produces palytoxin analogues including ovatoxins (OVTXs) and a putative palytoxin (p-PLTX), which can accumulate in marine organisms and may possibly lead to food intoxication. However, purified ovatoxins are not widely available and their toxicities are still unknown. The aim of this study was to improve understanding of the ecophysiology of Ostreopsis cf. ovata and its toxin production as well as to optimize the purification process for ovatoxin. During Ostreopsis blooms in 2011 and 2012 in Villefranche-sur-Mer (France, NW Mediterranean Sea), microalgae epiphytic cells and marine organisms were collected and analyzed both by LC-MS/MS and hemolysis assay. Results obtained with these two methods were comparable, suggesting ovatoxins...
Tipo: Text Palavras-chave: Ostreopsis cf. ovata; Palytoxin & ovatoxins; Culture; Seafood contamination; LC-MS/MS; Hemolysis assay; Mediterranean Sea.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00199/31025/29428.pdf
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Paralytic shellfish poison outbreaks in the Penze estuary: Environmental factors affecting toxin uptake in the oyster, Crassostrea gigas ArchiMer
Lassus, Patrick; Baron, Regis; Garen, Pierre; Truquet, Philippe; Masselin, Pierre; Bardouil, Michele; Leguay, Didier; Amzil, Zouher.
Several experiments using a self-regulated system were conducted to define the factors likely to influence the uptake of paralytic shellfish poison (PSP) by oysters in the Penze estuary (France, Brittany). Each 4-day experiment was carried out in a recirculated sea water system using 15 Pacific oysters (Crassostrea gigas) separated from each other and supplied with unfiltered natural seawater containing alternatively toxic (Alexandrium minutum) or non-toxic (Skeletonema costatum) algal diets. The food supply and exposure times to toxic diets were determined according to field studies of the Upstream and downstream movement of patches containing A. minutum. The experimental parameters corresponded roughly to the hydrological conditions generally observed in...
Tipo: Text Palavras-chave: Experimental contamination; Oyster toxicity; Dinophyceae; Toxin; PSP.
Ano: 2004 URL: http://archimer.ifremer.fr/doc/2004/publication-400.pdf
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Exposure to the Paralytic Shellfish Toxin Producer Alexandrium catenella Increases the Susceptibility of the Oyster Crassostrea gigas to Pathogenic Vibrios ArchiMer
Abi-khalil, Celina; Lopez-joven, Carmen; Abadie, Eric; Savar, Veronique; Amzil, Zouher; Laabir, Mohamed; Rolland, Jean-luc.
The multifactorial etiology of massive Crassostrea gigas summer mortalities results from complex interactions between oysters, opportunistic pathogens and environmental factors. In a field survey conducted in 2014 in the Mediterranean Thau Lagoon (France), we evidenced that the development of the toxic dinoflagellate Alexandrium catenella, which produces paralytic shellfish toxins (PSTs), was concomitant with the accumulation of PSTs in oyster flesh and the occurrence of C. gigas mortalities. In order to investigate the possible role of toxic algae in this complex disease, we experimentally infected C. gigas oyster juveniles with Vibrio tasmaniensis strain LGP32, a strain associated with oyster summer mortalities, after oysters were exposed to Alexandrium...
Tipo: Text Palavras-chave: Harmful algae; Environment; Interaction; Pathogens; Defense; Paralytic shellfish toxin.
Ano: 2016 URL: https://archimer.ifremer.fr/doc/00309/42016/41308.pdf
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From the sxtA4 Gene to Saxitoxin Production: What Controls the Variability Among Alexandrium minutum and Alexandrium pacificum Strains? ArchiMer
Geffroy, Solene; Lechat, Marc-marie; Le Gac, Mickael; Rovillon, Georges-augustin; Marie, Dominique; Bigeard, Estelle; Malo, Florent; Amzil, Zouher; Guillou, Laure; Caruana, Amandine.
Paralytic shellfish poisoning (PSP) is a human foodborne syndrome caused by the consumption of shellfish that accumulate paralytic shellfish toxins (PSTs, saxitoxin group). In PST-producing dinoflagellates such as Alexandrium spp., toxin synthesis is encoded in the nuclear genome via a gene cluster (sxt). Toxin production is supposedly associated with the presence of a 4th domain in the sxtA gene (sxtA4), one of the core genes of the PST gene cluster. It is postulated that gene expression in dinoflagellates is partially constitutive, with both transcriptional and post-transcriptional processes potentially co-occurring. Therefore, gene structure and expression mode are two important features to explore in order to fully understand toxin production processes...
Tipo: Text Palavras-chave: Alexandrium; Saxitoxins; SxtA4; Copy number variation; SxtA; Expression; Isoform.
Ano: 2021 URL: https://archimer.ifremer.fr/doc/00682/79402/81944.pdf
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Contribution of marine invertebrates to Ciguatera poisoning : the case study of French Polynesia ArchiMer
Darius, Ht; Viallon, J; Gatti, Cm; Chinain, M; Roué, M; Sibat, Manoella; Amzil, Zouher; Hess, Philipp; Vandersea, Mw; Litaker, Rw; Tester, Pa.
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Ano: 2018 URL: https://archimer.ifremer.fr/doc/00450/56181/57729.pdf
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β-N-methylamino-l-alanine (BMAA) and isomers: Distribution in different food web compartments of Thau lagoon, French Mediterranean Sea ArchiMer
Reveillon, Damien; Abadie, Eric; Sechet, Veronique; Masseret, Estelle; Hess, Philipp; Amzil, Zouher.
The neurotoxin BMAA (β-N-methylamino-l-alanine) and its isomer DAB (2,4-diaminobutyric acid) have been detected in seafood worldwide, including in Thau lagoon (French Mediterranean Sea). A cluster of amyotrophic lateral sclerosis (ALS), a neurodegenerative disease associated with BMAA, has also been observed in this region. Mussels, periphyton (i.e. biofilms attached to mussels) and plankton were sampled between July 2013 and October 2014, and analyzed using HILIC-MS/MS. BMAA, DAB and AEG (N-(2-aminoethyl)glycine) were found in almost all the samples of the lagoon. BMAA and DAB were present at 0.58 and 0.83, 2.6 and 3.3, 4.0 and 7.2 μg g−1 dry weight in plankton collected with nets, periphyton and mussels, respectively. Synechococcus sp., Ostreococcus...
Tipo: Text Palavras-chave: BMAA; Diatoms; Chaetoceros sp.; Seston; Mytilus galloprovincialis; HILIC-MS/MS.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00275/38607/37192.pdf
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