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Registros recuperados: 83 | |
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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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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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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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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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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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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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Amzil, Zouher; Sibat, Manoella; Royer, Florence; Savar, Veronique. |
The French Phytoplankton and Phycotoxins monitoring network (REPHY) recently found positive or dubious negative shellfish samples using lipophilic toxins mouse bioassay. These samples were analyzed by liquid chromatography (LC) in combination with mass spectrometry (MS) to detect the following toxins: okadaic acid (OA), dinophysistoxins (DTXs), pectenotoxins (PTXs), azaspiracids (AZAs), yessotoxins (YTXs), spirolides (SPXs) and gymnodimines (GYMs). Over the 2006-2007 period, chemical analyses revealed various lipophilic toxin profiles according to shellfish sampling locations. In addition to OA and/or PTX-2 and their derivatives, several other compounds were found for the first time in France: (1) during the summer of 2006, AZA-1 and AZA-2 in Queen... |
Tipo: Text |
Palavras-chave: LC MS/MS analyses; Shellfish; Yessotoxin group; Azaspiracid group; Lipophilic toxins. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4560.pdf |
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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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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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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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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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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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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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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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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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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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Registros recuperados: 83 | |
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