Consulta: creatorFacets:"Chomérat, Nicolas"
Registros recuperados: 12
Data/hora: 02/06/2024 11:53:48

Unsuspected intraspecific variability in the toxin production, growth and morphology of the dinoflagellate Alexandrium pacificum R.W. Litaker (Group IV) blooming in a South Western Mediterranean marine ecosystem, Annaba Bay (Algeria)
Provedor de dados: 5
Autores: Hadjadji, Imen; Laabir, Mohamed; Frihi, Hocine; Collos, Yves; Shao, Zhao Jun; Berrebi, Patrick; Abadie, Eric; Amzil, Zouher; Chomérat, Nicolas; Rolland, Jean-luc; Rieuvilleneuve, Fabien; Masseret, Estelle.
Physiological plasticity gives HABs species the ability to respond to variations in the surrounding environment. The aim of this study was to examine morphological and physiological variability in Alexandrium pacificum R.W. Litaker (Group IV) (former Alexandrium catenella) blooming in Annaba bay, Algeria. Monoclonal cultures of up to 30 strains of this neurotoxic dinoflagellate were established by the germination of single resting cysts from the surface sediment of this southern Mediterranean marine ecosystem. Ribotyping confirmed formally for the first time that A. pacificum is developing in Eastern Algerian waters. Toxin analyses of A. pacificum strains revealed substantial intraspecific variability in both the profile and toxin amount. However, the...
Tipo: Text
Palavras-chave: Alexandrium pacificum; Mediterranean; Toxin profile; Growth; Intraspecific variability.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00624/73620/73598.pdf

Taxonomy and toxicity of Prorocentrum from Perhentian Islands (Malaysia), with a description of a non-toxigenic species Prorocentrum malayense sp. nov. (Dinophyceae)
Provedor de dados: 5
Autores: Lim, Zhen Fei; Luo, Zhaohe; Lee, Li Keat; Hii, Kieng Soon; Teng, Sing Tung; Chan, Leo Lai; Chomérat, Nicolas; Krock, Bernd; Gu, Haifeng; Lim, Po Teen; Leaw, Chui Pin.
Thirteen isolates of Prorocentrum species were established from the coral reefs of Perhentian Islands Marine Park, Malaysia and underwent morphological observations and molecular characterization. Six species were found: P. caipirignum, P. concavum, P. cf. emarginatum, P. lima, P. mexicanum and a new morphotype, herein designated as P. malayense sp. nov. Prorocentrum malayense, a species closely related to P. leve, P. cf. foraminosum, P. sp. aff. foraminossum, and P. concavum (Clade A sensu Chomérat et al. 2018), is distinguished from its congeners as having larger thecal pore size and a more deeply excavated V-shaped periflagellar area. Platelet arrangement in the periflagellar area of P. malayense is unique, with the presence of platelet 1a and 1b,...
Tipo: Text
Palavras-chave: Diarrhetic shellfish poisoning; ITS2 secondary structure; Morphology; Periflagellar area; Phylogeny.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00485/59650/65985.pdf

Ostreopsis cf. ovata Bloom in Currais, Brazil: Phylogeny, Toxin Profile and Contamination of Mussels and Marine Plastic Litter
Provedor de dados: 5
Autores: Tibiriçá, Carlos Eduardo J. A.; Leite, Isabel P.; Batista, Talita V. V.; Fernandes, Luciano F.; Chomérat, Nicolas; Herve, Fabienne; Hess, Philipp; Mafra, Luiz.
Ostreopsis cf. ovata is a toxic marine benthic dinoflagellate responsible for harmful blooms affecting ecosystem and human health, mostly in the Mediterranean Sea. In this study we report the occurrence of a summer O. cf. ovata bloom in Currais, a coastal archipelago located on the subtropical Brazilian coast (~25° S). This bloom was very similar to Mediterranean episodes in many aspects: (a) field-sampled and cultivated O. cf. ovata cells aligned phylogenetically (ITS and LSU regions) along with Mediterranean strains; (b) the bloom occurred at increasing temperature and irradiance, and decreasing wind speed; (c) cell densities reached up to 8.0 × 104 cell cm−2 on fiberglass screen and 5.6 × 105 cell g−1 fresh weight on seaweeds; (d) and toxin profiles...
Tipo: Text
Palavras-chave: Harmful algal bloom; Benthic microalgae; Toxic dinoflagellates; Ovatoxin; Toxin transfer; Seafood safety; Marine pollution; Plastic litter; Biofilm formation.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00509/62037/66177.pdf

Ciguatoxin Occurrence in Food-Web Components of a Cuban Coral Reef Ecosystem: Risk-Assessment Implications
Provedor de dados: 5
Autores: Díaz-asencio, Lisbet; Clausing, Rachel J.; Vandersea, Mark; Chamero-lago, Donaida; Gómez-batista, Miguel; Hernández-albernas, Joan I.; Chomérat, Nicolas; Rojas-abrahantes, Gabriel; Litaker, Wayne; Tester, Patricia; Diogène, Jorge; Alonso-hernández, Carlos M.; Dechraoui Bottein, Marie-yasmine.
In Cuba, ciguatera poisoning associated with fish consumption is the most commonly occurring non-bacterial seafood-borne illness. Risk management through fish market regulation has existed in Cuba for decades and consists of bans on selected species above a certain weight; however, the actual occurrence of ciguatoxins (CTXs) in seafood has never been verified. From this food safety risk management perspective, a study site locally known to be at risk for ciguatera was selected. Analysis of the epiphytic dinoflagellate community identified the microalga Gambierdiscus. Gambierdiscus species included six of the seven species known to be present in Cuba (G. caribaeus, G. belizeanus, G. carpenteri, G. carolinianus, G. silvae, and F. ruetzleri). CTX-like...
Tipo: Text
Palavras-chave: Caribbean; Ciguatoxicity; QPCR; Trophic transfer; Ish; Food safety; Food security; Science-based management; Foodborne disease.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00597/70947/69189.pdf

A taxonomical study of benthic Prorocentrum species (Prorocentrales, Dinophyceae) from Anse Dufour (Martinique Island, eastern Caribbean Sea)
Provedor de dados: 5
Autores: Chomérat, Nicolas; Bilien, Gwenael; Zentz, Frédéric.
About 30 benthic Prorocentrum species have been described, some of which producing okadaic acid and derivatives involved in diarrhetic shellfish poisoning. The western Caribbean has been extensively studied for benthic dinoflagellates associated with ciguatera, and fifteen Prorocentrum species were described from mangroves and coral reefs of Belize. In contrast, no study reported the diversity of this genus in the Eastern Caribbean, especially in the Lesser Antilles. This study adds to the biodiversity knowledge in Martinique Island by investigating one site of the Caribbean coast from 2010 to 2017. Sediment samples were collected each year in March and studied taxonomically. Identification was realized morphologically by scanning electron microscopy,...
Tipo: Text
Palavras-chave: Caribbean; Dinoflagellates; LSU rDNA; Phylogeny; Prorocentrum; Taxonomy.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00469/58075/60483.pdf

Taxonomic characterization of a brackish water, bloom-forming Peridiniopsis species (Peridiniales, Dinophyceae) from Iraq
Provedor de dados: 5
Autores: Hameed, Hameed A.; Saburova, Maria; Chomérat, Nicolas.
Background The occurrence of a small brackish water bloom-forming dinoflagellate belonging to the genus Peridiniopsis is reported for the first time from the Shatt Al-Arab River in Iraq. Based on the study of cell morphology, this taxon was attributed to the recently described Peridiniopsis minima, recorded so far only from the Jiulongjiang River, China. Results The description of P. minima was extended to include some previously unreported details of the thecal surface, apical pore complex, and sulcus structure using light and scanning electron microscopy. Cells of this species from Iraq were oval to rhombic in shape and slightly dorso-ventrally compressed, with distinct red eyespot and endosymbiont nucleus. Cells were covered by a thin theca with the...
Tipo: Text
Palavras-chave: Dinophyceae; Dinoflagellates; Iraq; Morphology; Peridiniopsis; Shatt Al-Arab River; Taxonomy; SEM.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00664/77594/79608.pdf

Ostreopsis lenticularis Y. Fukuyo (Dinophyceae, Gonyaulacales) from French Polynesia (South Pacific Ocean): A revisit of its morphology, molecular phylogeny and toxicity
Provedor de dados: 5
Autores: Chomérat, Nicolas; Bilien, Gwenael; Derrien, Amelie; Henry, Kévin; Ung, André; Viallon, Jérôme; Darius, Hélène Taiana; Mahana Iti Gatti, Clémence; Roué, Mélanie; Hervé, Fabienne; Réveillon, Damien; Amzil, Zouher; Chinain, Mireille.
To date, the genus Ostreopsis comprises eleven described species, of which seven are toxigenic and produce various compounds presenting a major threat to human and environmental health. The taxonomy of several of these species however remains controversial, as it was based mostly on morphological descriptions leading, in some cases, to ambiguous interpretations and even possible misidentifications. The species Ostreopsis lenticularis was first described by Y. Fukuyo from French Polynesia using light microscopy observations, but without genetic information associated. The present study aims at revisiting the morphology, molecular phylogeny and toxicity of O. lenticularis based on the analysis of 47 strains isolated from 4 distinct locales of French...
Tipo: Text
Palavras-chave: ITS-5.8S rDNA; LSU rDNA; Microscopy; Ostreopsis lenticularis; Taxonomy; Toxins.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00486/59747/62887.pdf

Direct evidence for toxin production by   Pseudo-nitzschia plurisecta   (Bacillariophyceae) and extension of its distribution area
Provedor de dados: 5
Autores: Caruana, Amandine; Ayache, Nour; Raimbault, Virginie; Rétho, Michael; Hervé, Fabienne; Bilien, Gwenael; Amzil, Zouher; Chomérat, Nicolas.
We confirm an amnesic shellfish poisoning risk associated with domoic acid production by the species Pseudo-nitzschia plurisecta and determine the toxin profile, which includes three domoic acid isomers. Although the species was reported once in European waters, along the Spanish Atlantic coast, here we describe and characterize P. plurisecta collected during the first occurrence in French Atlantic waters. Three strains (IFR-PPL-15.1, 15.2 and 15.3) were isolated from French coastal water samples in June 2015. These strains were identified and characterized by microscopic observation, molecular (ITS region sequencing and phylogenetic analysis) and metabolite (toxins and pigments) analyses. The cell shape is lanceolate and the valve contains a central...
Tipo: Text
Palavras-chave: Coastal monitoring; Domoic acid; Pigment composition; Pseudo-nitzschia plurisecta; Taxonomic identification; Toxic diatoms.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00505/61687/66033.pdf

Laciniporus arabicus   gen. et sp. nov. (Dinophyceae, Peridiniales), a new thecate, marine, sand-dwelling dinoflagellate from the northern Indian Ocean (Arabian Sea)
Provedor de dados: 5
Autores: Saburova, Maria; Chomérat, Nicolas.
A new thecate, photosynthetic, sand‐dwelling marine dinoflagellate, Laciniporus arabicus gen. et sp. nov., is described from the subtidal sediments of the Omani coast in the Arabian Sea, northern Indian Ocean, based on detailed morphological and molecular data. Cells of L. arabicus are small (16.2‐30.1 μm long and 13.1‐23.2 μm wide), dorsoventrally compressed, with a small apical flap‐shaped projection pointing to the left. The thecal plate pattern is distinguished by minute first precingular plate and sulcus, which extends into the epitheca, with large anterior and right sulcal plates. The Kofoidian thecal tabulation is Po, X, 4′, 2a, 7′′, 6c, 6s, 5′′′, 2′′′′. Morphologically, the revealed plate pattern has an affinity to the Peridiniales, and LSU rDNA...
Tipo: Text
Palavras-chave: Arabian Sea; Benthic dinoflagellates; Dinophyceae; Laciniporus arabicus; Molecular phylogeny; Morphology; Oman; Peridiniales; Taxonomy.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00454/56614/58315.pdf

Discovery of a New Clade Nested Within the Genus Alexandrium (Dinophyceae): Morpho-molecular Characterization of Centrodinium punctatum (Cleve) F.J.R. Taylor
Provedor de dados: 5
Autores: Li, Zhun; Mertens, Kenneth; Nézan, Elisabeth; Chomérat, Nicolas; Bilien, Gwenael; Iwataki, Mitsunori; Shin, Hyeon Ho.
Investigation of phytoplankton from East China Sea of the Pacific Ocean, offshore Réunion Island of the Indian Ocean, and the French Atlantic coast revealed a species of poorly known armored fusiform dinoflagellate. To clarify this species, morphology and phylogeny based on mitochondrial and nuclear protein gene sequence (Cox1, Cob and Hsp90) concatenated with the SSU, ITS region and LSU rDNA sequences were analysed. Epifluorescence and scanning electron microscopy observations revealed that the nucleus of the specimen was elongated, sausage-shaped and located equatorially on the left lateral side of the cell, and that the plate formula is Po, 3′, 1a, 6″, 6C, 8S, 5‴, 1p, 2′‴. These morphological features indicate that the species can be assigned to...
Tipo: Text
Palavras-chave: Fusiform dinoflagellate; Centrodinium; Alexandrium; Morphology; Phylogeny.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00483/59496/62364.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

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