Consulta: creatorFacets:"Sibat, Manoella"
Registros recuperados: 40
Data/hora: 06/06/2024 19:18:34

First Evidence of Palytoxin and 42-Hydroxy-palytoxin in the Marine Cyanobacterium Trichodesmium
Provedor de dados: 5
Autores: Kerbrat, Anne Sophie; Amzil, Zouher; Pawlowiez, Ralph; Golubic, Stjepko; Sibat, Manoella; Darius, Helene Taiana; Chinain, Mireille; Laurent, Dominique.
Marine pelagic diazotrophic cyanobacteria of the genus Trichodesmium (Oscillatoriales) are widespread throughout the tropics and subtropics, and are particularly common in the waters of New Caledonia. Blooms of Trichodesmium are suspected to be a potential source of toxins in the ciguatera food chain and were previously reported to contain several types of paralyzing toxins. The toxicity of water-soluble extracts of Trichodesmium spp. were analyzed by mouse bioassay and Neuroblastoma assay and their toxic compounds characterized using liquid chromatography coupled with tandem mass spectrometry techniques. Here, we report the first identification of palytoxin and one of its derivatives, 42-hydroxy-palytoxin, in field samples of Trichodesmium collected in...
Tipo: Text
Palavras-chave: Cyanobacteria; Trichodesmium; Palytoxin; 42-hydroxy-palytoxin; Clupeotoxism.
Ano: 2011
URL: https://archimer.ifremer.fr/doc/00040/15143/12576.pdf

Report on the first detection of pectenotoxin-2, spirolide-A and their derivatives in French shellfish
Provedor de dados: 5
Autores: 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

Influence of Environmental Factors on the Paralytic Shellfish Toxin Content and Profile of Alexandrium catenella (Dinophyceae) Isolated from the Mediterranean Sea
Provedor de dados: 5
Autores: 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

Chemically mediated interactions between Microcystis and Planktothrix: Impact on their physiology and metabolic profiles
Provedor de dados: 5
Autores: 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...
Tipo: Text
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00374/48515/48794.pdf

High resolution mass spectrometry for quantitative analysis and untargeted screening of algal toxins in mussels and passive samplers
Provedor de dados: 5
Autores: 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

Contribution of marine invertebrates to Ciguatera poisoning : the case study of French Polynesia
Provedor de dados: 5
Autores: Darius, Ht; Viallon, J; Gatti, Cm; Chinain, M; Roué, M; Sibat, Manoella; Amzil, Zouher; Hess, Philipp; Vandersea, Mw; Litaker, Rw; Tester, Pa.
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00450/56181/57729.pdf

First insight on metabolomics workflows and differences between dinoflagellate: characterization and discrimination of modern and ancient strains and their algal growth
Provedor de dados: 5
Autores: Mondeguer, Florence; Souard, Florence; Guitton, Yann; Latimier, Marie; Quere, Julien; Sibat, Manoella; Hess, Philipp; Siano, Raffaele.
Aquatic ecosystems worldwide have been negatively affected by eutrophication, many of them driven by increasing nutrient inputs from untreated domestic sewage and industrial and agricultural wastewater. During their life cycle, Alexandrium minutum and Scrippsiella donghaienis can produce resistant and revivable cysts that can accumulate in the sediments of the coastal marine environment for hundreds of years. As a working hypothesis, we presumed that these two genera have preserved their adaptation to such ecosystem changes in the form of cysts in the old sediments. From revivified cysts, some cultures of toxic and non-toxic dinoflagellates (A. minutum and S. donghaienis) were analyzed by a untargeted metabolomics approach by LC-HRMS to study the possible...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00440/55199/56664.pdf

Toxicological Investigations on the Sea Urchin Tripneustes gratilla (Toxopneustidae, Echinoid) from Anaho Bay (Nuku Hiva, French Polynesia): Evidence for the Presence of Pacific Ciguatoxins
Provedor de dados: 5
Autores: 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

Effects of pH and Nutrients (Nitrogen) on Growth and Toxin Profile of the Ciguatera-Causing Dinoflagellate Gambierdiscus polynesiensis (Dinophyceae)
Provedor de dados: 5
Autores: Longo, Sébastien; Sibat, Manoella; Taiana Darius, Hélène; Hess, Philipp; Chinain, Mireille.
Ciguatera poisoning is a foodborne disease caused by the consumption of seafood contaminated with ciguatoxins (CTXs) produced by dinoflagellates in the genera Gambierdiscus and Fukuyoa. Ciguatera outbreaks are expected to increase worldwide with global change, in particular as a function of its main drivers, including changes in sea surface temperature, acidification, and coastal eutrophication. In French Polynesia, G. polynesiensis is regarded as the dominant source of CTXs entering the food web. The effects of pH (8.4, 8.2, and 7.9), Nitrogen:Phosphorus ratios (24N:1P vs. 48N:1P), and nitrogen source (nitrates vs. urea) on growth rate, biomass, CTX levels, and profiles were examined in four clones of G. polynesiensis at different culture age (D10, D21,...
Tipo: Text
Palavras-chave: Gambierdiscus polynesiensis; French Polynesia; Ciguatera; Ciguatoxins; LC-MS; MS; Toxin profile; Nitrate; Urea; Culture medium acidification.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00662/77382/78981.pdf

Relative Molar Response of lipophilic marine algal toxins in liquid chromatography electrospray ionization mass spectrometry
Provedor de dados: 5
Autores: Zendong, Suzie Zita; Sibat, Manoella; Herrenknecht, Christine; Hess, Philipp; Mccarron, Pearse.
Rationale Accurate quantitative analysis of lipophilic toxins by liquid chromatography-mass spectrometry (LC-MS) requires calibration solution reference materials (RMs) for individual toxin analogs. Untargeted analysis is aimed at identifying a vast number of compounds and thus validation of fully quantitative untargeted methods is not feasible. However, a semi-quantitative approach allowing for profiling is still required and will be strengthened by knowledge of the relative molar response (RMR) of analogs in liquid chromatography-mass spectrometry (LC-MS) with electrospray ionization (ESI). Methods RMR factors were evaluated for toxins from the okadaic acid (OA/DTXs), yessotoxin (YTX), pectenotoxin (PTX), azaspiracid (AZA) and cyclic imine (CI) toxin...
Tipo: Text
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00387/49877/50434.pdf

Maitotoxin-4, a Novel MTX Analog Produced by Gambierdiscus excentricus
Provedor de dados: 5
Autores: Pisapia, Francesco; Sibat, Manoella; Herrenknecht, Christine; Lhaute, Korian; Gaiani, Greta; Ferron, Pierre-jean; Fessard, Valerie; Fraga, Santiago; Nascimento, Silvia M.; Litaker, R. Wayne; Holland, William C.; Roullier, Catherine; Hess, Philipp.
Maitotoxins (MTXs) are among the most potent toxins known. These toxins are produced by epi-benthic dinoflagellates of the genera Gambierdiscus and Fukuyoa and may play a role in causing the symptoms associated with Ciguatera Fish Poisoning. A recent survey revealed that, of the species tested, the newly described species from the Canary Islands, G. excentricus, is one of the most maitotoxic. The goal of the present study was to characterize MTX-related compounds produced by this species. Initially, lysates of cells from two Canary Island G. excentricus strains VGO791 and VGO792 were partially purified by (i) liquid-liquid partitioning between dichloromethane and aqueous methanol followed by (ii) size-exclusion chromatography. Fractions from...
Tipo: Text
Palavras-chave: Gambierdiscus excentricus; Maitotoxin-4; Bioguided fractionation; Size-exclusion chromatography (LH-20); Neuro-2a (N2a) assay; LC-HRMS/MS (Q-Tof 6550); LC-LRMS/MS (API4000 QTrap).
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00392/50320/51001.pdf

Innovative metabolomic workflows to study growth kinetics dinoflagellate cysts revived from modern and ancient sediments
Provedor de dados: 5
Autores: Mondeguer, Florence; Souard, Florence; Guitton, Yann; Allard, Pierre-marie; Elie, Nicolas; Sibat, Manoella; Latimier, Marie; Quere, Julien; Wolfender, Jean-luc; Siano, Raffaele; Hess, Philipp.
Aquatic ecosystems worldwide have been negatively affected by eutrophication, many of them driven by increasing nutrient inputs from untreated domestic sewage and industrial and agricultural wastewater. During their life cycle, Alexandrium minutum and Scrippsiella donghaienis can produce resistant and revivable cysts that can accumulate in the sediments of the coastal marine environment for hundreds of years. As a working hypothesis, we presumed that these two genera have preserved their adaptation to such ecosystem changes in the form of cysts in the old sediments. From revivified cysts, some cultures of toxic and non-toxic dinoflagellates (A. minutum and S. donghaienis) were analyzed by a metabolomic approach to study the possible adaptive responses of...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00464/57591/59769.pdf

Assessment of Ciguatera and Other Phycotoxin-Related Risks in Anaho Bay (Nuku Hiva Island, French Polynesia): Molecular, Toxicological, and Chemical Analyses of Passive Samplers
Provedor de dados: 5
Autores: Roué, Mélanie; Smith, Kirsty F.; Sibat, Manoella; Viallon, Jérôme; Henry, Kévin; Ung, André; Biessy, Laura; Hess, Philipp; Darius, Hélène Taiana; Chinain, Mireille.
Ciguatera poisoning is a foodborne illness caused by the consumption of seafood contaminated with ciguatoxins (CTXs) produced by dinoflagellates from the genera Gambierdiscus and Fukuyoa. The suitability of Solid Phase Adsorption Toxin Tracking (SPATT) technology for the monitoring of dissolved CTXs in the marine environment has recently been demonstrated. To refine the use of this passive monitoring tool in ciguateric areas, the effects of deployment time and sampler format on the adsorption of CTXs by HP20 resin were assessed in Anaho Bay (Nuku Hiva Island, French Polynesia), a well-known ciguatera hotspot. Toxicity data assessed by means of the mouse neuroblastoma cell-based assay (CBA-N2a) showed that a 24 h deployment of 2.5 g of resin allowed...
Tipo: Text
Palavras-chave: Ciguatera monitoring; Gambierdiscus; Ciguatoxins; SPATT passive samplers; HP20 resin; CBA-N2a; LC-MS; MS; WS artificial substrate; QPCR; HTS metabarcoding.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00629/74143/73670.pdf

Preliminary metabolomic approach on cyanobacterial co-cultures: Chemically mediated interactions between Microcystis and Planktothrix
Provedor de dados: 5
Autores: 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

Chemically mediated interactions between   Microcystis   and   Planktothrix   : impact on their growth, morphology and metabolic profiles
Provedor de dados: 5
Autores: Briand, Enora; Reubrecht, Sébastien; Mondeguer, Florence; Sibat, Manoella; Hess, Philipp; Amzil, Zouher; Bormans, Myriam.
Freshwater cyanobacteria are known for their ability to produce bioactive compounds, some of which have been described as allelochemicals. Using a combined approach of co‐cultures and analyses of metabolic profiles, we investigated chemically mediated interactions between two cyanobacterial strains, Microcystis aeruginosa PCC7806 and Planktothrix agardhii PCC7805. More precisely, we evaluated changes in growth, morphology and metabolite production and release by both interacting species. Co‐culture of Microcystis with Planktothrix resulted in a reduction of the growth of Planktothrix together with a decrease of its trichome size and alterations in the morphology of its cells. The production of intracellular compounds by Planktothrix showed a slight...
Tipo: Text
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00470/58152/60632.pdf

Use of Mass Spectrometry to Determine the Diversity of Toxins Produced by Gambierdiscus and Fukuyoa Species from Balearic Islands and Crete (Mediterranean Sea) and the Canary Islands (Northeast Atlantic)
Provedor de dados: 5
Autores: Estevez, Pablo; Sibat, Manoella; Leão-martins, José Manuel; Tudó, Angels; Rambla-alegre, Maria; Aligizaki, Katerina; Diogène, Jorge; Gago-martinez, Ana; Hess, Philipp.
Over the last decade, knowledge has significantly increased on the taxonomic identity and distribution of dinoflagellates of the genera Gambierdiscus and Fukuyoa. Additionally, a number of hitherto unknown bioactive metabolites have been described, while the role of these compounds in ciguatera poisoning (CP) remains to be clarified. Ciguatoxins and maitotoxins are very toxic compounds produced by these dinoflagellates and have been described since the 1980s. Ciguatoxins are generally described as the main contributors to this food intoxication. Recent reports of CP in temperate waters of the Canary Islands (Spain) and the Madeira archipelago (Portugal) triggered the need for isolation and cultivation of dinoflagellates from these areas, and their...
Tipo: Text
Palavras-chave: Maitotoxins; Ciguatoxins; Gambierdiscus; Fukuyoa; LC-MS; MS; HRMS; QToF; Ciguatera poisoning.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00629/74081/73530.pdf

Tissue Distribution and Elimination of Ciguatoxins in Tridacna maxima (Tridacnidae, Bivalvia) Fed Gambierdiscus polynesiensis
Provedor de dados: 5
Autores: 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

Tectus niloticus (Tegulidae, Gastropod) as a Novel Vector of Ciguatera Poisoning: Detection of Pacific Ciguatoxins in Toxic Samples from Nuku Hiva Island (French Polynesia)
Provedor de dados: 5
Autores: 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

Ovatoxin-a and Palytoxin Accumulation in Seafood in Relation to Ostreopsis cf. ovata Blooms on the French Mediterranean Coast
Provedor de dados: 5
Autores: 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

Quantitative analysis of azaspiracids in Azadinium spinosum cultures
Provedor de dados: 5
Autores: 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

Pinnatoxin G is responsible for atypical toxicity in mussels (Mytilus galloprovincialis) and clams (Venerupis decussata) from Ingril, a French Mediterranean lagoon
Provedor de dados: 5
Autores: 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

Liquid Chromatography Coupled to High-Resolution Mass Spectrometry for the Confirmation of Caribbean Ciguatoxin-1 as the Main Toxin Responsible for Ciguatera Poisoning Caused by Fish from European Atlantic Coasts
Provedor de dados: 5
Autores: Estevez, Pablo; Sibat, Manoella; Leão-martins, José Manuel; Reis Costa, Pedro; Gago-martínez, Ana; Hess, Philipp.
Ciguatera poisoning (CP) is a common seafood intoxication mainly caused by the consumption of fish contaminated by ciguatoxins. Recent studies showed that Caribbean ciguatoxin-1 (C-CTX1) is the main toxin causing CP through fish caught in the Northeast Atlantic, e.g., Canary Islands (Spain) and Madeira (Portugal). The use of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) combined with neuroblastoma cell assay (N2a) allowed the initial confirmation of the presence of C-CTX1 in contaminated fish samples from the abovementioned areas, nevertheless the lack of commercially available reference materials for these particular ciguatoxin (CTX) analogues has been a major limitation to progress research. The EuroCigua project allowed the...
Tipo: Text
Palavras-chave: Ciguatoxins; HRMS; Q-TOF; Ciguatera poisoning; C-CTX1; Fragmentation pathways.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00624/73630/73067.pdf

Workflows novateurs pour une analyse métabolomique plus claire et plus intégrative
Provedor de dados: 5
Autores: Mondeguer, Florence; Allard, Pierre-marie; Souard, Florence; Elie, Nicolas; Guitton, Yann; Sibat, Manoella; Siano, Raffaele.
During their life cycle, Alexandrium minutum and Scrippsiella donghaienis can produce resistant and revivable cysts that can accumulate in marine sediments for hundreds of years. Our working hypothesis assumes that these two genera have "recorded" their adaptation to ecosystem changes in these cells preserved in the form of cysts. From these revived cysts, toxic and non-toxic dinoflagellate cultures (Alexandrium minutum and Scrippsiella donghaienis) were analyzed by a metabolomic approach to investigate the possible adaptive responses of phytoplankton to these changes in coastal ecosystems. The strains were obtained from isotopically dated sediments, 1986 and 1996 for "old" and 2006 for "modern". In total, 84 samples were obtained. Each experimental...
Tipo: Text
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00485/59662/62721.pdf

Intraspecific Variability in the Toxin Production and Toxin Profiles of In Vitro Cultures of Gambierdiscus polynesiensis (Dinophyceae) from French Polynesia
Provedor de dados: 5
Autores: Longo, Sebastien; Sibat, Manoella; Viallon, Jérôme; Darius, Hélène Taiana; Hess, Philipp; Chinain, Mireille.
Ciguatera poisoning (CP) is a foodborne disease caused by the consumption of seafood contaminated with ciguatoxins (CTXs) produced by dinoflagellates in the genera Gambierdiscus and Fukuyoa. The toxin production and toxin profiles were explored in four clones of G. polynesiensis originating from different islands in French Polynesia with contrasted CP risk: RIK7 (Mangareva, Gambier), NHA4 (Nuku Hiva, Marquesas), RAI-1 (Raivavae, Australes), and RG92 (Rangiroa, Tuamotu). Productions of CTXs, maitotoxins (MTXs), and gambierone group analogs were examined at exponential and stationary growth phases using the neuroblastoma cell-based assay and liquid chromatography–tandem mass spectrometry. While none of the strains was found to produce known MTX compounds,...
Tipo: Text
Palavras-chave: Gambierdiscus polynesiensis; Ciguatera; Ciguatoxins; Gambierone; 44-methylgambierone; LC-MS/MS; CBA-N2a; Toxin profiles.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00599/71134/69449.pdf

Experimental evidence of dietary ciguatoxin accumulation in an herbivorous coral reef fish
Provedor de dados: 5
Autores: Clausing, Rachel J.; Losen, Barbara; Oberhaensli, Francois R.; Darius, H. Taiana; Sibat, Manoella; Hess, Philipp; Swarzenski, Peter W.; Chinain, Mireille; Bottein, Marie-yasmine Dechraoui.
Ciguatoxins (CTXs) are potent algal toxins that cause widespread ciguatera poisoning and are found ubiquitously in coral reef food webs. Here we developed an environmentally-relevant, experimental model of CTX trophic transfer involving dietary exposure of herbivorous fish to the CTX-producing microalgae Gambierdiscus polynesiensis. Juvenile Naso brevirostris were fed a gel-food embedded with microalgae for 16 weeks (89 cells g.1 fish daily, 0.4 ¦Ìg CTX3C equiv kg.1 fish). CTXs in muscle tissue were detectable after 2 weeks at levels above the threshold for human intoxication (1.2 ¡À 0.2 ¦Ìg CTX3C equiv kg.1). Although tissue CTX concentrations stabilized after 8 weeks (¡«3 ¡À 0.5 ¦Ìg CTX3C equiv kg.1), muscle toxin burden (total ¦Ìg CTX in muscle tissue)...
Tipo: Text
Palavras-chave: Ciguatoxin; Bioaccumulation; Growth dilution; Trophic transfer; Herbivorous fish; Experimental model.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00442/55339/60476.pdf

Metabolomic Profiles of Dinophysis acuminata and Dinophysis acuta Using Non-Targeted High-Resolution Mass Spectrometry: Effect of Nutritional Status and Prey
Provedor de dados: 5
Autores: Garcia-portela, Maria; Reguera, Beatriz; Sibat, Manoella; Altenburger, Andreas; Rodriguez, Francisco; Hess, Philipp.
Photosynthetic species of the genus Dinophysis are obligate mixotrophs with temporary plastids (kleptoplastids) that are acquired from the ciliate Mesodinium rubrum, which feeds on cryptophytes of the Teleaulax-Plagioselmis-Geminigera clade. A metabolomic study of the three-species food chain Dinophysis-Mesodinium-Teleaulax was carried out using mass spectrometric analysis of extracts of batch-cultured cells of each level of that food chain. The main goal was to compare the metabolomic expression of Galician strains of Dinophysis acuminata and D. acuta that were subjected to different feeding regimes (well-fed and prey-limited) and feeding on two Mesodinium (Spanish and Danish) strains. Both Dinophysis species were able to grow while feeding on both...
Tipo: Text
Palavras-chave: Dinophysis physiology; Lipophilic toxins; Non-targeted analysis; Metabolomics.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00439/55077/56508.pdf

Sélection de workflows adaptés à une analyse métabolomique plus transparente et intégrative
Provedor de dados: 5
Autores: Mondeguer, Florence; Allard, Pierre-marie; Souard, Florence; Elie, Nicolas; Guitton, Yann; Sibat, Manoella; Siano, Raffaele.
During their life cycle, Alexandrium minutum and Scrippsiella donghaienis can produce resistant and revivable cysts that can accumulate in marine sediments for hundreds of years. Our working hypothesis assumes that these two genera have "recorded" their adaptation to ecosystem changes in these cells preserved in the form of cysts. From these revived cysts, toxic and non-toxic dinoflagellate cultures (Alexandrium minutum and Scrippsiella donghaienis) were analyzed by a metabolomic approach to investigate the possible adaptive responses of phytoplankton to these changes in coastal ecosystems. The strains were obtained from isotopically dated sediments, 1986 and 1996 for "ancient" and 2006 for "modern". In total, 84 samples were obtained. Each experimental...
Tipo: Text
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00498/60941/64339.pdf

Toxicity and Growth Assessments of Three Thermophilic Benthic Dinoflagellates (Ostreopsis cf. ovata, Prorocentrum lima and Coolia monotis) Developing in the Southern Mediterranean Basin
Provedor de dados: 5
Autores: 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

Characterization of toxin-producing strains of Dinophysis spp. (Dinophyceae) isolated from French coastal waters, with a particular focus on the D. acuminata-complex
Provedor de dados: 5
Autores: Séchet, Veronique; Sibat, Manoella; Bilien, Gwenael; Carpentier, Liliane; Rovillon, Georges-augustin; Raimbault, Virginie; Malo, Florent; Gaillard, Sylvain; Perrière-rumebe, Myriam; Hess, Philipp; Chomérat, Nicolas.
Dinoflagellates of the genus Dinophysis are the most prominent producers of Diarrhetic Shellfish Poisoning (DSP) toxins which have an impact on public health and on marine aquaculture worldwide. In particular, Dinophysis acuminata has been reported as the major DSP agent in Western Europe. Still, its contribution to DSP events in the regions of the English Channel and the Atlantic coast of France, and the role of the others species of the Dinophysis community in these areas are not as clear. In addition, species identification within the D. acuminata complex has proven difficult due to their highly similar morphological features. In the present study, 30 clonal strains of the dominant Dinophysis species have been isolated from French coasts including the...
Tipo: Text
Palavras-chave: Dinophysis spp; . Phylogeny; Taxonomy; Toxin profiles.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00679/79081/81880.pdf

Detoxification enhancement in the gymnodimine-contaminated grooved carpet shell, Ruditapes decussatus (Linne)
Provedor de dados: 5
Autores: Medhioub, Walid; Gueguen, Marielle; Lassus, Patrick; Bardouil, Michele; Truquet, Philippe; Sibat, Manoella; Nejib, Medhioub; Philippe, Soudant; Mejdeddine, Kraiem; Amzil, Zouher.
In the Gulf of Gabes (Tunisia, Eastern Mediterranean sea), the grooved carpet shell Ruditapes decussatus has been seen to contain persistent levels of gymnodimine (GYM) for several years. The present experimental work represents the first attempt to assess detoxification kinetics of fast-acting toxins (FAT) in marine molluscs fed specific diets of non-toxic algae (Isochrysis galbana). To find an optimal detoxification method, two experiments were performed in which clams were first fed the toxic dinoflagellate Karenia selliformis to artificially contaminate them with GYM, thus simulating the effect of natural toxic episodes. As a second step, the same clams were fed a non-toxic algae, I. galbana. to speed up the detoxification process. Changes in toxin...
Tipo: Text
Palavras-chave: Ruditapes decussates; Grooved carpet shell; Karenia selliformis; Gymnodimine; Toxicity; Detoxification.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/2010/publication-7488.pdf

Evidence for the Range Expansion of Ciguatera in French Polynesia: A Revisit of the 2009 Mass-Poisoning Outbreak in Rapa Island (Australes Archipelago)
Provedor de dados: 5
Autores: Chinain, Mireille; Mahana Iti Gatti, Clémence; Ung, André; Cruchet, Philippe; Revel, Taina; Viallon, Jérôme; Sibat, Manoella; Varney, Patrick; Laurent, Victoire; Hess, Philipp; Taiana Darius, Hélène.
Ciguatera poisoning (CP) results from the consumption of seafood contaminated with ciguatoxins (CTXs). This disease is highly prevalent in French Polynesia with several well-identified hotspots. Rapa Island, the southernmost inhabited island in the country, was reportedly free of CP until 2007. This study describes the integrated approach used to investigate the etiology of a fatal mass-poisoning outbreak that occurred in Rapa in 2009. Symptoms reported in patients were evocative of ciguatera. Several Gambierdiscus field samples collected from benthic assemblages tested positive by the receptor binding assay (RBA). Additionally, the toxicity screening of ≈250 fish by RBA indicated ≈78% of fish could contain CTXs. The presence of CTXs in fish was confirmed...
Tipo: Text
Palavras-chave: Ciguatera poisoning; French Polynesia; Gambierdiscus; Ciguatoxins; Epidemiology; Toxicological analyses; Risk management; Climate change.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00662/77362/78933.pdf

Influence of environmental parameters on Karenia selliformis toxin content in culture
Provedor de dados: 5
Autores: 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

Characterization of ovatoxin-h, a new ovatoxin analog, and evaluation of chromatographic columns for ovatoxin analysis and purification
Provedor de dados: 5
Autores: 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

First report on azaspiracid and yessotoxin groups detection in French shellfish
Provedor de dados: 5
Autores: 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

Modelling the accumulation of PSP toxins in Thau Lagoon oysters (Crassostrea gigas) from trials using mixed cultures of Alexandrium catenella and Thalassiosira weissflogii
Provedor de dados: 5
Autores: 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

Spirolide uptake and detoxification by Crassostrea gigas exposed to the toxic dinoflagellate Alexandrium ostenfeldii
Provedor de dados: 5
Autores: Medhioub, Walid; Lassus, Patrick; Truquet, Philippe; Bardouil, Michele; Amzil, Zouher; Sechet, Veronique; Sibat, Manoella; Soudant, Philippe.
Oysters (Crassostrea gigas) were exposed 4 days to cultures of the toxic dinoflagellate Alexandrium ostenfeldii (strain CCMP1773) that produces spirolides belonging to fast acting toxins (FAT) and let depurate for 7 days. During depuration, oysters were either fed the non-toxic algae Isochrysis galbana Tahitian clone (T. Iso) or starved. The objectives of this experiment were to evaluate (i) spirolide uptake and depuration by oysters (ii) spirolide effects on oysters and (iii) oyster recovery according to food supply during depuration. A. ostenfeldii cells were filtered and ingested by oysters while faeces contained numerous intact cells of the toxic diet. This suggested that ingested cells were not totally digested by oysters. Contents of spirolides (SPX)...
Tipo: Text
Palavras-chave: Spirolides; Alexandrium ostenfeldii; Contamination; Depuration; Crassostrea gigas; Inflammatory responses.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00098/20953/18740.pdf

First report on amnesic and diarrhetic toxins detection in French scallops during 2004-05 monitoring surveys
Provedor de dados: 5
Autores: 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

Metabolomic Analysis of Marine Microalgae Using High Resolution Mass Spectrometry for Taxonomic Comparisons and Screening of Marine Biotoxins
Provedor de dados: 5
Autores: Hess, Philipp; Mondeguer, Florence; Glauner, Thomas; Wust, Bernard; Sibat, Manoella; Zendong, Suzie Zita; Herrenknecht, Christine; Sechet, Veronique.
Out of the circa 5000 microalgae known, around 100 marine species of unicellular algae have been shown to produce several hundred biotoxins worldwide. Such biotoxins may be harmful to man through consumption of fish and shellfish exposed to such algae or through direct contact. Many official methods aimed at the detection of such toxins had traditionally been based on biological assays, due to the lack of reference compounds. Recently, legislation for shellfish safety in Europe introduced targeted MS screening for lipophilic toxins. Due to globalization of trade and climate change, there is a need to develop methods for untargeted screening to fully protect consumer safety, e.g. LC-HRMS. For this purpose we studied the metabolomes of marine microalgae...
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00179/29037/27473.pdf

Evidence of the bioaccumulation of ciguatoxins in giant clams (Tridacna maxima) exposed to Gambierdiscus spp. cells
Provedor de dados: 5
Autores: Roue, Melanie; Darius, Helene Taiana; Picot, Sandy; Ung, Andre; Viallon, Jerome; Gaertner-mazouni, Nabila; Sibat, Manoella; Amzil, Zouher; Chinain, Mireille.
Ciguatera Fish Poisoning (CFP) is a foodborne disease classically related to the consumption of tropical coral reef fishes contaminated with ciguatoxins (CTXs), neurotoxins produced by dinoflagellates of the Gambierdiscus genus. Severe atypical ciguatera-like incidents involving giant clams, a marine resource highly consumed in the South Pacific, are also frequently reported in many Pacific Islands Countries and Territories. The present study was designed to assess the ability of giant clams to accumulate CTXs in their tissues and highlight the potential health risks associated with their consumption. Since giant clams are likely to be exposed to both free-swimming Gambierdiscus cells and dissolved CTXs in natural environment, ex situ contamination...
Tipo: Text
Palavras-chave: Giant clams; Ex situ contamination; Ciguatoxins; Gambierdiscus polynesiensis; LC-MS/MS; Neuroblastoma cell-based assay.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00343/45415/45123.pdf

Diversity and Toxicity of the Genus Coolia Meunier in Brazil, and Detection of 44-Methyl Gambierone in Coolia tropicalis
Provedor de dados: 5
Autores: Tibiriçá, Carlos Eduardo Junqueira De Azevedo; Sibat, Manoella; Fernandes, Luciano Felício; Bilien, Gwenael; Chomérat, Nicolas; Hess, Philipp; Mafra, Luiz L.
Coolia is a genus of marine benthic dinoflagellates which is widely distributed in tropical and temperate zones. Toxicity has been reported in selected Coolia species, although the identity of causative compounds is still controversial. In this study, we investigated the taxonomical and toxicological aspects of Coolia species from Brazil. Since light- and electron microscopy-based morphology was not enough to distinguish small-celled species, ITS and LSU D1-D3 phylogenetic analyses were used for species definition. Cultures of Coolia palmyrensis and Coolia santacroce were established from samples collected along the northeastern Brazilian coast, the first record of both species in South Atlantic waters. Cultures of Coolia malayensis and Coolia tropicalis...
Tipo: Text
Palavras-chave: Benthic microalgae; Toxic dinoflagellates; Toxicity assay; Cooliatoxin; 44-methyl gambierone.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00630/74186/73789.pdf