Consulta: subjectFacets:"Azaspiracid"
Registros recuperados: 9
Data/hora: 04/06/2024 09:00:45

Évaluation d’une suite de bio-essais pour la détection et l’étude de composés lipophiles de micro-organismes marins issus de mollusques bivalves et de leur environnement
Provedor de dados: 5
Autores: Geiger, Marie.
The context of this study was the assessment of the safety of edible bivalve molluscs. Bivalve can indeed accumulate high concentrations of phycotoxins into their hepatopancreas, potentially leading to human intoxication outbreaks after consumption of such contaminated bivalves. In order to ensure the protection of shellfish consumers, regulated toxins are monitored using physico-chemical techniques. In parallel, emerging toxins, that can be putatively produced by microalgae or marine fungi, are monitored using the intraperitoneal mouse bioassay. However, this bioassay suffers ethical and methodological drawbacks. Thus, the objective of this work was to assess the ability of a bioassay suite to detect lipophilic toxins. This suite was composed of three...
Tipo: Text
Palavras-chave: Cytotoxicité; Larves de diptères; Activité antibactérienne; Toxines lipophiles; Micro-algues; Dinoflagellés; Micromycètes; Penicillium; Acide okadaïque; Azaspiracide; Pinnatoxine G; Vulcanodinium rugosum; Prorocentrum lima; Azadinium spinosum; Beauveria brongniartii; Cytotoxicity; Diptera larvae; Antibacterial activity; Lipophilic toxins; Microalgae; Dinoflagellates; Marine fungi; Penicillium; Okadaic acid; Azaspiracid; Pinnatoxin G; Vulcanodinium rugosum; Azadinium spinosum; Prorocentrum lima; Beauveria brongniartii.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00183/29426/27787.pdf

Dissolved azaspiracids are absorbed and metabolized by blue mussels (Mytilus edulis)
Provedor de dados: 5
Autores: Jauffrais, Thierry; Kilcoyne, Jane; Herrenknecht, Christine; Truquet, Philippe; Sechet, Veronique; Miles, Christopher O.; Hess, Philipp.
The relationship between azaspiracid shellfish poisoning and a small dinoflagellate, Azadinium spinosum, has been shown recently. The organism produces AZA1 and -2, while AZA3 and other analogues are metabolic products formed in shellfish. We evaluated whether mussels were capable of accumulating dissolved AZA1 and -2, and compared the toxin profiles of these mussels at 24 h with profiles of those exposed to live or lysed A. spinosum. We also assessed the possibility of preparative production of AZA metabolites by exposing mussels to semi-purified AZA1. We exposed mussels to similar concentration of AZAs: dissolved AZA1+2 (crude extract) at 7.5 and 0.75 µg L-1, dissolved AZA1+2 (7.5 µg L-1) in combination with Isochrysis affinis galbana, and lysed and live...
Tipo: Text
Palavras-chave: Dissolved marine biotoxins; AZA; Tissue distribution; Bivalve molluscs; LC-MS/MS; Azaspiracid.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00136/24757/22867.pdf

A new potentially toxic Azadinium species (Dinophyceae) from the Mediterranean Sea, A. dexteroporum sp. nov.
Provedor de dados: 5
Autores: Percopo, Isabella; Siano, Raffaele; Rossi, Rachele; Soprano, Vittorio; Sarno, Diana; Zingone, Adriana.
A new photosynthetic planktonic marine dinoflagellate, Azadinium dexteroporum sp. nov., is described from the Gulf of Naples (South Tyrrhenian Sea, Mediterranean Sea). The plate formula of the species, Po, cp, X, 4, 3a, 6, 6C, 5?S, 6'" and 2, is typical for this recently described genus. Azadinium dexteroporum is the smallest rep-resentative of the genus (8.5m average length, 6.2m average width) and shares the presence of a small antapical spine with the type species A.spinosum and with A.polongum. However, it differs from all other Azadinium species for the markedly asymmetrical Po plate and the position of the ventral pore, which is located at the right posterior end of the Po plate. Another peculiarity of A.dexteroporum is the pronounced concavity of...
Tipo: Text
Palavras-chave: Azadinium; Azaspiracid; Dinoflagellate; LC; MS-TOF; LTER-MC; Mediterranean Sea; Phylogeny; Taxonomy.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00171/28199/27278.pdf

Production and Isolation of Azaspiracid-1 and -2 from Azadinium spinosum Culture in Pilot Scale Photobioreactors
Provedor de dados: 5
Autores: Jauffrais, Thierry; Kilcoyne, Jane; Sechet, Veronique; Herrenknecht, Christine; Truquet, Philippe; Herve, Fabienne; Berard, Jean-baptiste; Nulty, Ciara; Taylor, Sarah; Tillmann, Urban; Miles, Christopher O.; Hess, Philipp.
Azaspiracid (AZA) poisoning has been reported following consumption of contaminated shellfish, and is of human health concern. Hence, it is important to have sustainable amounts of the causative toxins available for toxicological studies and for instrument calibration in monitoring programs, without having to rely on natural toxin events. Continuous pilot scale culturing was carried out to evaluate the feasibility of AZA production using Azadinium spinosum cultures. Algae were harvested using tangential flow filtration or continuous centrifugation. AZAs were extracted using solid phase extraction (SPE) procedures, and subsequently purified. When coupling two stirred photobioreactors in series, cell concentrations reached 190,000 and 210,000 cell·mL−1 at...
Tipo: Text
Palavras-chave: Solid phase extraction; Photobioreactor; Chemostat; Dinoflagellate; Micro-algae; LC-MS/MS; Tangential flow filtration; Azaspiracid; HP-20.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00088/19875/17526.pdf

Adding new pieces to the Azadinium (Dinophyceae) diversity and biogeography puzzle: Non-toxigenic Azadinium zhuanum sp. nov. from China, toxigenic A. poporum from the Mediterranean, and a non-toxigenic A. dalianense from the French Atlantic
Provedor de dados: 5
Autores: Luo, Zhaohe; Krock, Bernd; Mertens, Kenneth; Nezan, Elisabeth; Chomerat, Nicolas; Bilien, Gwenael; Tillmann, Urban; Gu, Haifeng.
The marine planktonic dinophyceaen genus Azadinium is a primary source of azaspiracids, but due to their small size its diversity may be underestimated and information on its biogeography is still limited. A new Azadinium species, A. zhuanum was obtained from the East China Sea and Yellow Sea of China by incubating surface sediments. Five strains were established by isolating single germinated cells and their morphology was examined with light microscopy and scanning electron microscopy. Azadinium zhuanum was characterized by a plate pattern of Po, cp, X, 4′, 2a, 6′′, 6C, 5S, 6′′′, 2′′′′, by a distinct ventral pore at the junction of Po, the first and fourth apical plates, and a conspicuous antapical spine. Moreover, Azadinium poporum was obtained for the...
Tipo: Text
Palavras-chave: Azadinium; Azaspiracid; AZA-2; AZA-2 phosphate; Biogeography; China; French Atlantic; Mediterranean Sea.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00386/49765/51155.pdf

Effect of Azadinium spinosum on the feeding behaviour and azaspiracid accumulation of Mytilus edulis
Provedor de dados: 5
Autores: Jauffrais, Thierry; Contreras, Andrea; Herrenknecht, Christine; Truquet, Philippe; Sechet, Veronique; Tillmann, Urban; Hess, Philipp.
Azadinium spinosum, a small toxic dinoflagellate, was recently isolated and identified as a primary producer of azaspiracid toxins (AZAs). Previous experiments related to AZA accumulation in blue mussels upon direct feeding with A. spinosum revealed increased mussel mortality and had negative effects on the thickness of the digestive gland tubules. Therefore we conducted follow up experiments in order to study effects of A. spinosum on mussel feeding behaviour. Individual assessment of mussel feeding time activity (FTA), clearance rate (CR), filtration rate (TFR), absorption rate (AR), faeces and pseudofaeces production were carried out on mussel fed either toxic (A. spinosum) or non-toxic (Isochrisis aff. galbana (T-Iso)) diets. Furthermore, AZA...
Tipo: Text
Palavras-chave: Bivalve molluscs; Mussel; Ecophysiology; AZA biotransformation; AZA accumulation; Trophic transfer; Dinoflagellate; Azaspiracid.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00090/20174/17832.pdf

Structure Elucidation, Relative LC–MS Response and In Vitro Toxicity of Azaspiracids 7–10 Isolated from Mussels (Mytilus edulis)
Provedor de dados: 5
Autores: Kilcoyne, Jane; Twiner, Michael J.; Mccarron, Pearse; Crain, Sheila; Giddings, Sabrina D.; Foley, Barry; Rise, Frode; Hess, Philipp; Willdns, Alistair L.; Miles, Christopher O.
Azaspiracids (AZAs) are marine biotoxins produced by dinoflagellates that can accumulate in shellfish, which if consumed can lead to poisoning events. AZA7–10, 7–10, were isolated from shellfish and their structures, previously proposed on the basis of only LC–MS/MS data, were confirmed by NMR spectroscopy. Purified AZA4–6, 4–6, and 7–10 were accurately quantitated by qNMR and used to assay cytotoxicity with Jurkat T lymphocyte cells for the first time. LC–MS(MS) molar response studies performed using isocratic and gradient elution in both selected ion monitoring and selected reaction monitoring modes showed that responses for the analogues ranged from 0.3 to 1.2 relative to AZA1, 1. All AZA analogues tested were cytotoxic to Jurkat T lymphocyte cells in a...
Tipo: Text
Palavras-chave: Azaspiracid; Structure confirmation; LC-MS molar response; NMR; Mass spectrometry; Purification; Jurkat T; Toxicity.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00269/38059/36190.pdf

Azaspiracid accumulation, detoxification and biotransformation in blue mussels (Mytilus edulis) experimentally fed Azadinium spinosum
Provedor de dados: 5
Autores: Jauffrais, Thierry; Marcaillou-le Baut, Claire; Herrenknecht, Christine; Truquet, Philippe; Sechet, Veronique; Nicolau, Elodie; Tillmann, Urban; Hess, Philipp.
Azadinium spinosum (Elbrächter and Tillmann), a small marine dinoflagellate, has been recently described as a de novo producer of azaspiracid-1 and -2 (AZA1 and -2) diarrhoeic toxins. A culture of A. spinosum was established in our laboratory and optimised for pilot-scale production of this organism, to evaluate and understand AZA1 and -2 accumulation and biotransformation in blue mussels (Mytilus edulis) fed with A. spinosum.  Adult mussels were continuously exposed to A. spinosum over 1 week in 160 L cylindrical conical tanks. Three different diets were tested for contamination: 5000, 10 000 cells mL−1 of A. spinosum and a mixture of 5000 cells mL−1 of A. spinosum with 5000 cells mL−1 of Isochrysis aff. galbana (T-Iso, CCAP 927/14). During the subsequent...
Tipo: Text
Palavras-chave: Azaspiracid; Azadinium spinosum; Marine biotoxins; AZA; Tissue distribution; Histology; Bivalve molluscs; Liquid chromatography coupled to tandem mass spectrometry.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00088/19877/17566.pdf

Effects of Heating on Proportions of Azaspiracids 1–10 in Mussels (     Mytilus edulis     ) and Identification of Carboxylated Precursors for Azaspiracids 5, 10, 13, and 15
Provedor de dados: 5
Autores: Kilcoyne, Jane; Mccarron, Pearse; Hess, Philipp; Miles, Christopher O.
Azaspiracids (AZAs) are marine biotoxins that induce human illness following the consumption of contaminated shellfish. European Union regulation stipulates that only raw shellfish are tested, yet shellfish are often cooked prior to consumption. Analysis of raw and heat-treated mussels (Mytilus edulis) naturally contaminated with AZAs revealed significant differences (up to 4.6-fold) in AZA1–3 (1–3) and 6 (6) values due to heat-induced chemical conversions. Consistent with previous studies, high levels of 3 and 6 were detected in some samples that were otherwise below the limit of quantitation before heating. Relative to 1, in heat-treated mussels the average (n = 40) levels of 3 (range, 11–502%) and 6 (range, 3–170%) were 62 and 31%, respectively. AZA4...
Tipo: Text
Palavras-chave: Azaspiracid; Decarboxylation; Hydroxylation; Chemical conversion; Heating mass spectrometry; Metabolism.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00303/41433/41005.pdf