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| Registros recuperados: 49 | |
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| Goudenege, David; Travers, Marie-agnes; Lemire, Astrid; Petton, Bruno; Haffner, Philippe; Labreuche, Yannick; Tourbiez, Delphine; Mangenot, Sophie; Calteau, Alexandra; Mazel, Didier; Nicolas, Jean-louis; Jacq, Annick; Le Roux, Frederique. |
| Oyster diseases caused by pathogenic vibrios pose a major challenge to the sustainability of oyster farming. In France since 2012 a disease affecting specifically adult oysters has been associated with the presence of Vibrio aestuarianus. Here, by combining genome comparison, phylogenetic analyses and high throughput infections of strains isolated before or during the recent outbreaks, we show that virulent strains cluster into two V. aestuarianus lineages independently of the sampling dates. The bacterial lethal dose was not different between strains isolated before or after 2012. Hence the emergence of a new highly virulent clonal strain is unlikely. Each lineage comprises nearly identical strains, the majority of them being virulent, suggesting that... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00226/33685/32530.pdf |
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| Robert, Rene; Nicolas, Jean-louis; Conan, Rony. |
| For lack of antibiotics, King scallop larviculture faces high mortalities. In the experimental mollusc hatchery of Argenton (Brittany, France), the presence of a vibrio, Vibrio pectinicida, associated with the stocks seems to be responsible for this low survival rate. As prophylactic methods are difficult to implement in the current structures (water sterilization, egg decontamination, isolation of the stocks), the addition of chloramphenicol is the only solution to protect the stocks. However, the use of this antibiotic, considered as dangerous for man, has been prohibited in animal production throughout the whole of Europe since 1994. The action of two other antibiotics, the erythromycine and the oxolinic acid, has been searched for in Pecten maximus... |
| Tipo: Text |
Palavras-chave: Acide oxolinique; Erythromycine; Antibiotiques; Coquille St Jacques; Pecten maximus L.; Développement larvaire. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/1998/publication-6199.PDF |
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| Robert, Rene; Chretiennot-dinet, Marie-josèphe; Kaas, Raymond; Martin-jezequel, Véronique; Moal, Jeanne; Le Coz, Jean-rene; Nicolas, Jean-louis; Bernard, Eudes; Connan, Jean-paul; Le Dean, Loic; Le Gourrierec, Gaetane; Leroy, Bertrand; Quere, Claudie. |
| in mollusc hatcheries. Consequently, we assessed themost commonly used species to establish their growth and size profiles, their cytomorphological, biochemical, biomolecular identification as well as their cytometer signs, and also their ability to grow under extreme conditions of temperature and salinity. This work aimed at matching the conformity of the strains used in Argenton (dispatched to most of the French commercial hatcheries) to those of a referenced culture collection. A previous screening preceded this study, because of the 45 species and/or clones held originally, Argenton kept no more than 15 species. As most of the latter are also represented in referenced collection, our strains are therefore correctly identified. On the other hand, the... |
| Tipo: Text |
Palavras-chave: Ecological limits; Biomolecular profile; Flow cytometry; Biochemical composition; Cytomorphology; Phytoplankton; Mollusc; Hatchery; Ecotolérance; Profil biomoléculaire; Cytométrie en flux; Composition biochimique; Cytomorphologie; Phytoplancton; Mollusques; Ecloserie. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/rapport-1546.pdf |
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| Tanniou, A.; Vandanjon, L.; Incera, M.; Serrano Leon, Esteban; Husa, V.; Le Grand, Jacqueline; Nicolas, Jean-louis; Poupart, N.; Kervarec, N.; Engelen, A.; Walsh, R.; Guerard, F.; Bourgougnon, N.; Stiger-pouvreau, Valerie. |
| Sargassum muticum, an invasive brown macroalga presently distributed along European Atlantic coasts from southern Portugal to the south coast of Norway, was studied on a large geographical scale for its production of phenolic compounds with potential industrial applications and their chemical and biological activities. S. muticum can produce high biomass in Europe, which could be exploited to supply such compounds. S. muticum was collected in Portugal, Spain, France, Ireland and Norway (three sites/country) to examine the effect of the latitudinal cline and related environmental factors. Assays focused particularly on polyphenols and their activities. Crude acetone–water extracts were purified using solid phase extraction (SPE) and antioxidant and... |
| Tipo: Text |
Palavras-chave: Antioxidant activities; Antibacterial activities; Latitudinal gradient; Phenolic compounds; Solid phase extraction; Sargassum muticum. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00171/28221/32175.pdf |
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| Omnes, Marie-helene; Temey, Yann; Daniel, Jean-yves; Nicolas, Jean-louis. |
| Bacterial infections have been suspected to be one cause of variable success in the incubation of turbot (Scophthalmus maximus) eggs. The assessment of bacterial flora (bacterial environment) associated with ova, sperm and developing eggs was conducted just at stripping gametes and during incubation. Gametes were collected in sterile conditions before fertilization. Eggs were held in an open-circulation 401 incubator, at 13 degree C during 6 days until hatching. Samples of those were collected every day. They were rinsed several times with sterile seawater, counted and grown. Viable counts of bacteria were determined on two media, Zobell and TCBS agar. Epibiotic bacteria on the surface of the eggs and impact on the chorion were observed at scanning... |
| Tipo: Text |
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| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00199/31015/29425.pdf |
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| Nicolas, Jean-louis; Corre, S; Gauthier, Gilles; Robert, Rene; Ansquer, Dominique. |
| Scallop Pecten maximus larvae have been cultured at the Argenton and Tinduff (Brittany, France) hatcheries with antibiotic treatment (chloramphenicol at 8 ppm) for 15 yr. Without treatment, outbreak of disease has normally occurred between Day 12 and Day 19 or sometimes earlier. A bacteriological study of larvae reared with and without antibiotic was performed over a 4 yr period. Among the collected strains, 2 clusters (C and F) of vibrios were present at high densities only in larvae cultured without treatment. One cluster (C) was routinely isolated over the 4 yr of study, while the other (F) was collected only in the third year. Their virulence with respect to scallop larvae and their lack of infectivity with respect to oyster larvae were demonstrated in... |
| Tipo: Text |
Palavras-chave: Larvae; Bivalve; Vibrio; Scallop. |
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00090/20077/17716.pdf |
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| Cochennec-laureau, Nathalie; Baud, Jean-pierre; Bedier, Edouard; Boudry, Pierre; Huvet, Arnaud; Nicolas, Jean-louis; Pepin, Jean-francois; Petton, Bruno. |
| Ce bilan comprend deux parties : la première est dédiée à une synthèse des travaux présentés lors des journées « Surmortalités des huîtres creuses, Crassostrea gigas » les 8 et 9 décembre 2009 et, la seconde partie, à une proposition d'un projet de recherche spécifique 2010-2012 en complément des propositions de « sortie de crise ». Contexte Les mortalités estivales de l'huître creuse, Crassostrea gigas, sont décrites depuis une vingtaine d'années en France mais également au Japon, en Corée, aux USA et en Australie. Ces phénomènes ou « syndrome des mortalités estivales » ont fait l'objet d'une étude pluridisciplinaire en France entre 2001 et 2006 (Défi MOREST). Toutefois, en 2008 et 2009, l'ostréiculture française a du faire face à deux épisodes de... |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/2010/acte-7393.pdf |
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| Gay, Melanie; Waechter, Magali; Lambert, Christophe; Escoubas, Jean-michel; Cochennec, Nathalie; Nicolas, Jean-louis; Berthe, Franck; Le Roux, Frédérique. |
| Nowadays, cupped oyster, Crassostrea gigas, production is the main shellfish production in France. Spats cultivated on most farms are usually collected in the wild, but hatchery spats are becoming more numerous, and represent around 10% of today's cultivated spats. During the summer period, when the temperatures are higher, high mortality rates have been regularly observed in cupped in oyster C. gigas (60 to 100%) spats since 1991, both in hatcheries-nurseries and in their natural habitat. Over the last five years, these episodes have become a big concern for all the professionals. |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Pathogène; Vibrio splendidus; Bactériologie. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/acte-3277.pdf |
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| Labreuche, Yannick; Lambert, Christophe; Soudant, Philippe; Boulo, Viviane; Huvet, Arnaud; Nicolas, Jean-louis. |
| The strategies used by bacterial pathogens to circumvent host defense mechanisms remain largely undefined in bivalve molluscs. In this study, we investigated experimentally the interactions between the Pacific oyster (Crassostrea gigas) immune system and Vibrio aestuarianus strain 01/32, a pathogenic bacterium originally isolated from moribund oysters. First, an antibiotic-resistant V. aestuarianus strain was used to demonstrate that only a limited number of bacterial cells was detected in the host circulatory system, suggesting that the bacteria may localize in some organs. Second, we examined the host defense responses to V. aestuarianus at the cellular and molecular levels, using flow-cytometry and real-time PCR techniques. We showed that hemocyte... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Oyster; Pathogenesis; Vibrio aestuarianus; Bivalve immunity. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2182.pdf |
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| Madec, Stephanie; Pichereau, Vianney; Jacq, Annick; Paillard, Mathieu; Boisset, Claire; Guerard, Fabienne; Paillard, Christine; Nicolas, Jean-louis. |
| Vibrio tapetis causes the brown ring disease in the Japanese clam Ruditapes philippinarum while Vibrio aestuarianus is associated with massive oyster mortalities. As extracellular proteins are often associated with the virulence of pathogenic bacteria, we undertook a proteomic approach to characterize the secretomes of both vibrios. The extracellular proteins (ECPs) of both species were fractionated by SEC-FPLC and in vitro assays were performed to measure the effects of each fraction on hemocyte cellular parameters (phagocytosis and adhesion). Fractions showing a significant effect were subjected to SDS-PAGE, and proteins were identified by nano LC-MS/MS. 45 proteins were identified for V. aestuarianus and 87 for V. tapetis. Most of them belonged to outer... |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00242/35334/34576.pdf |
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| Le Roux, Frédérique; Gay, Melanie; Lambert, Christian; Waechter, Magali; Poubalanne, Saravanne; Chollet, Bruno; Nicolas, Jean-louis; Berthe, Franck. |
| French mollusc production is based mainly on the Pacific cupped oyster, Crassostrea gigas. Since 1991, annual mass mortality of juveniles has been reported during summer months. These recurring episodes concern professionals who fear that like Portugese oyster, C. angulata, C gigas could in turn disappear following one of these epizooties. Previously, bacteriological analysis of moribund oyster juveniles yielded an isolate of a Vibrio splendidus biovar H strain, named TNEMF6. This isolate was demonstrated to be pathogenic to Crassostrea gigas spat by experimental challenge. To study the association between summer oyster mortality and presence of TNEMF6 cluster strains, Vibrionaceae fauna were isolated from infected spat along the French Atlantic coast... |
| Tipo: Text |
Palavras-chave: Vibrio splendidus; Virulence; Epidemiology; PCR RFLP; Oyster mortality. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-565.pdf |
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| Normand, Julien; Li, Ronghua; Quillien, Virgile; Nicolas, Jean-louis; Boudry, Pierre; Pernet, Fabrice; Huvet, Arnaud. |
| Pacific oyster Crassostrea gigas suffers from chronic or sporadic mortality outbreaks worldwide, resulting from infectious diseases and/or physiological disorders triggered by environmental factors. Since 2008, ostreid herpesvirus OsHV-1 μVar has been identified as the main agent responsible for mass mortality of juvenile oysters in Europe. Previous studies of genome-wide expression profiling have provided candidate genes that potentially contribute to genetically-based resistance to summer mortality. To assess their value in determining resistance to the juvenile mass mortality that has occurred in France since 2008, we analyzed the expression of 17 candidate genes in an experimental infection by OsHV-1 μVar, and in an in vivo field experiment. Individual... |
| Tipo: Text |
Palavras-chave: Molluscs; Gene expression profiling; Inhibitor of kappa B; Summer mortality; Ostreid herpesvirus. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00177/28823/27325.pdf |
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| Person-le Ruyet, Jeanine; Baudin-laurenc, Félix; Devauchelle, Nicole; Metailler, Robert; Nicolas, Jean-louis; Robin, Jean; Guillaume, Jean. |
| Turbot, Scophthalmus maximus Rafinesque, 1810: Psetta maxima Linnaeus, 1758, is a marine demersal carnivorous flatfish of the Scophthalmidae family, relatively abundant in Europe: from 68°N down to Morocco 30°N. It is also abundant in the Mediterranean Sea as far as Turkey. But it is lacking in the Black Sea, where two very close species, S. maeoticus and S. ponticus, are naturally found (Figure 1). Turbot are caught on sand, gravel, or mixed bottoms at a depth of 20 to 70 m. The total annual catch is less than 10,000 for all Europe in spite of the high market price: from 10 to 25 U.S. $/kg according to the country and the size of the fish (0.65 to 15 kg). Turbot was selected for aquaculture in the early 1970s, both in the United Kingdom and France due to... |
| Tipo: Text |
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| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00048/15930/13356.pdf |
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| Nicolas, Jean-louis; Renault, Tristan; Gagnaire, Beatrice; Garcia, Celine; Le Roux, F; Miossec, Laurence; Pepin, Jean-francois; Saulnier, Denis. |
| L'un des objectifs principaux des travaux en pathologie des mollusques est d'identifier et d'étudier des agents infectieux capables d'induire des maladies et des mortalités chez les coquillages, en particulier, chez I'huître creuse, Crassostrea gigas, espèce principalement exploitée en France. Ces travaux semblent d'autant plus indispensables qu'il n'existait pas, jusqu'à ces dernières années, de maladies identifiées chez I'huître creuse en Europe excepté le virus herpès suspecté dès 1995 de provoquer des mortalités de naissain (Renault et al, 1995). Les principales maladies des espèces proches sont dues à des parasites comme Haplosporidium nelsoni (Ford et Heskin, 1987) et Perkinsus marinus Olivier et al, 1 998) pour Crassostrea virginica, Marteilia... |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00304/41535/40743.pdf |
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| Huvet, Arnaud; Royer, J.; Moal, J.; Burgeot, Thierry; Lapègue, Sylvie; Boulo, Viviane; Nicolas, Jean-louis; Lambert, C.. |
| Les résultats du programme MOREST démontrent l'existence d'une composante génétique à la survie estivale du naissain et nous permettent de disposer aujourd'hui d'huTtres « résistantes» (R) et « susceptibles» (S) aux mortalités estivales (Dégremont et aL, 2002, 2005). La forte héritabilité estimée face à un tel système multifactoriel permet de suspecter que le caractère sélectionné puisse être gouverné par un ou un trés petit nombre de gènes sur une région chromosomique donnée. D'après le modèle d'interaction suspecté entre l'environnement, l'huître et des pathogènes opportunistes, une hiérarchie des facteurs, conduisant aux mortalités, permet de montrer qu'aucun d'entre eux ne peut provoquer à lui seul les mortalités mais que leur combinaison est... |
| Tipo: Text |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00306/41706/40917.pdf |
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| Asmani, Katia; Petton, Bruno; Le Grand, Jacqueline; Mounier, Jerome; Robert, Rene; Nicolas, Jean-louis. |
| The first aim of this study was to determine the stocking density limits for Pacific oyster Crassostrea gigas larvae reared in flow-through system (FTS) and recirculating aquaculture systems (RAS). The second aim was to examine biofilm formation on the larval tank wall and its interaction with larvae growth. Three larvae concentrations were tested: 50, 150, and 300 mL−1. Chemical parameters and larvae performance were measured. The biofilm was observed by scanning electron microscopy, and its bacterial composition was investigated by pyrosequencing analysis of part of the 16S rRNA gene. The highest growth (13 µm day–1), survival (87%) and metamorphosis (50%) rates were observed in FTS at 50 larvae mL–1, while lower and similar performances occurred at... |
| Tipo: Text |
Palavras-chave: Pacific oyster; Larval culture; High stocking density; Biofilm; Filamentous bacteria. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00395/50611/51324.pdf |
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| Jacq, E; Moal, Jeanne; Samain, Jean-francois; Corre, S; Daniel, J; Nicolas, Jean-louis; Cochard, Jean-claude; Fera, P. |
| Larval rearings were performed with seawater either freshly pumped or after storage in a pond. Concerning bacterial populations these waters were characterized by a high diversity, little sized bacteria whose few of them (1%) were cultivable on Zobell medium. In the tanks, the bacterial ecosystem was modified by the presence of antibiotics, larvae and algae: the diversity was lowered, the cellular volume was increased by a factor 2 to 5, 100% bacteria were cultivable and chloramphenicol resistant, and their metabolism changed. Taxonomic screening showed no differences among the two waters neither at the beginning nor at the end of the rearings. However, depending on the water (stored or not) differences were identified for bacterial physiology and... |
| Tipo: Text |
Palavras-chave: Marine aquaculture; Pond culture; Scallop culture; Ecology; Antibiotics; Organic matter; Grazing; Carbohydrates; Mathematical models; Modelling; Growth; Bacterial diseases; Biological production; Culture tanks; Larvae; Rearing. |
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-914.pdf |
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| Genard, Bertrand; Larouche, Olivier; Nicolas, Jean-louis; Miner, Philippe; Beaudin, Marie-lou; Tremblay, Rejean. |
| The aim of this project was to evaluate the impact of probiotic (Phaeobacter gallaeciensis, X34 strain) treatment on the complete development (from veliger to metamorphosis) of Pecten maximus larvae in the context of a bacterial challenge and in conditions more representative of hatchery practices. To that effect, the present study was divided into two main steps. In the first, we used in vitro analyses (antibiograms and microplate assays) to validate the inhibition abilities of X34 on the growth of four Vibrio pathogen species. During the second step, we added pathogens (Vibrio pectenicida) into rearing tanks after two weeks of pre-treatment with the probiotic and then followed the larval development of Pecten maximus through the monitoring of survival... |
| Tipo: Text |
Palavras-chave: Probiotics; Hatchery; Bacterial challenge; Larval development; Pecten maximus; Phaeobacter gallaeciensis; Vibrio. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00213/32429/30895.pdf |
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| Labreuche, Yannick; Soudant, Philippe; Goncalves, Madeleine; Lambert, Christophe; Nicolas, Jean-louis. |
| Vibrio aestuarianus strain 01/32 was previously shown to be pathogenic to Crassostrea gigas juveniles. To investigate virulence mechanisms of this pathogen, we studied the toxicity to oysters of its extracellular products (ECPs). ECPs displayed lethality to animals, with a LD50 value of 3.3 mu g/g body weight. To determine the oyster cellular immune responses induced by these ECPs, we further examined in vitro their effects on C. gigas hemocytes, using flow cytometric-based hemocyte assays. Treatment of hemolymph with ECPs caused a significant inhibition of hemocyte phagocytosis and adhesive capabilities. In contrast, the pathway of reactive oxygen species production was enhanced by higher ECP concentrations. Exposure of hemocytes to live bacteria induced... |
| Tipo: Text |
Palavras-chave: Vibrio aestuarianus; ECPs; Crassostrea gigas; ROS production; Adhesion; Phagocytosis; Flow cytometry; Bivalve immunity. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1035.pdf |
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| Registros recuperados: 49 | |
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