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| Registros recuperados: 49 | |
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| Longeon, Arlette; Peduzzi, Jean; Barthelemy, Michel; Corre, Sophie; Nicolas, Jean-louis; Guyot, Museum National D'Histoire Naturelle. |
| A marine bacterium, X 153, was isolated from a pebble collected at St. Anne du Portzic (France). By 16S ribosomal DNA gene sequence analysis, X153 strain was identified as a Pseudoalteromonas sp. close to P. piscicida. The crude culture of X153 was highly active against human pathogenic strains involved in dermatologic diseases, and marine bacteria including various ichthyopathogenic Vibrio strains. The active substance occurred both in bacterial cells and in culture supernatant. An antimicrobial protein was purified to homogeneity by a 4-step procedure using size-exclusion and ion-exchange chromatography. The highly purified P-153 protein is anionic, and sodium dodecylsulfate polyacrylamide gel electrophoresis gives all apparent molecular mass of 87 kDa.... |
| Tipo: Text |
Palavras-chave: Probiotic bacteria; Pseudoalteromonas; Antimicrobial protein. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-426.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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| Azandegbe, Afi; Gamier, Matthieu; Andrieux, Francoise; Kerouel, Roger; Philippon, Xavier; Nicolas, Jean-louis. |
| Vibrio aestuarianus is frequently found in coastal areas and can infect and induce mortalities in the pacific oyster Crassostrea gigas. However, nothing is known about its distribution and seasonality in the estuarine environment, especially where oyster farming is practiced. Its occurrence was investigated in sediment and oyster haemolymph at 2 oyster farms in Brittany (France) over 2 yr during 2 periods, from June to September 2007 and from February to June 2008. Total heterotrophic bacteria (HB) were cultured on marine agar while total Vibrio spp. and V. aestuarianus were selectively numerated using thiosulfate citrate bile salts sucrose agar (TCBS agar) and the species-specific hybridisation method, respectively. PCR was performed to detect V.... |
| Tipo: Text |
Palavras-chave: Vibrio aestuarianus; Crassostrea gigas Sediment; Seasonal abundance; Colony-blot. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00017/12813/9756.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... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00242/35334/34576.pdf |
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| Travers, Marie-agnes; Degremont, Lionel; De Lorgeril, Julien; Azema, Patrick; Montagnani, Caroline; Benabdelmouna, Abdellah; Nicolas, Jean-louis; Le Roux, Frederique. |
| En 2012, le nombre de cas de mortalités d’huîtres creuses adultes rapportés dans le cadre du réseau Repamo, et dans lesquels la bactérie Vibrio aestuarianus a été isolée, a fortement augmenté. Afin d’apporter de premiers éléments de réponse concernant cette augmentation, les objectifs de cette étude étaient de déterminer si l’émergence/la ré-émergence de V. aestuarianus était associée (i) à l’apparition d’un génotype bactérien particulier et/ou (ii) à une sensibilité accrue de certains animaux. L’Ifremer dispose d’une collection de souches bactériennes appartenant majoritairement au genre Vibrio et qui comporte différents isolats de V. aestuarianus, collectés depuis 2001 pendant ou hors épisodes de mortalité. La comparaison de ces isolats en termes de... |
| Tipo: Text |
Palavras-chave: Vibrio aestuarianus; Huître creuse; Crassostrea gigas; Bactérie; Ré-émergenece; Virulence; Génome; Statut immunitaire; Génétique. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00229/34037/32430.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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| 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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| Azandegbe, Afi; Poly, Franck; Andrieux, Francoise; Kerouel, Roger; Philippon, Xavier; Nicolas, Jean-louis. |
| Bacterial community structure and some biogeochemical parameters were studied in the sediment of two Pacific oyster farming sites, Aber Benoît (AB) and Rivière d'Auray (RA) in Brittany (France), to examine the ecological impact of oysters and to evaluate the emission of sulfide and ammonia from sediment. At AB, the organic matter accumulated in the sediment beneath the oyster tables was rapidly mineralized, with strong fluxes of ammonia and sulfide that reached 1014 μmol m−2 h−1 - and 215 μmol m−2 h−1, respectively, in June 2007. At RA, the fluxes were about half as strong on average and better distributed through the year. The ammonia and sulfide concentrations in the overlying water never reached levels that would be toxic to oysters in either site, nor... |
| Tipo: Text |
Palavras-chave: Sediment; Biogeochemical parameters; Fluxes; Bacterial structure; Crassostrea gigas. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00079/19010/17083.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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| 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... |
| Tipo: Text |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00304/41535/40743.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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| Renault, Tristan; Allain, Gwenhael; Arzul, Isabelle; Chollet, Bruno; Cobret, Laetitia; De Decker, Sophie; Faury, Nicole; Ferrand, Sylvie; Francois, Cyrille; Garcia, Celine; Haffner, Philippe; Joly, Jean-pierre; Miossec, Laurence; Morga, Benjamin; Nicolas, Jean-louis; Omnes, Emmanuelle; Pepin, Jean-francois; Saulnier, Denis; Schikorski, David; Segarra, Amelie. |
| Abnormal mortality outbreaks occurred in the majority of Pacific oyster (Crassostrea gigas) producing areas in France in 2008 during the summer period. These outbreaks were usually sudden and severe (up to 100%) and affected essentially spat (oysters less than 1 year-old) and juveniles (12 to 18 month-old oysters). Crassostrea gigas was the single affected species Mortality outbreaks were first observed from mid May to mid June in Brittany, Vendée, Charente Maritime and Mediterranean coast A second episode of massive mortality events was reported at the end of June and the beginning of July. All oyster production sites were affected except some particular locations including Arcachon Bay and Brittany. Mortality occurred latter in Arcachon Bay in August.... |
| Tipo: Text |
Palavras-chave: Abnormal mortality; Oysters; Crassostrea gigas; Pathogens. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00014/12554/9420.pdf |
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| Paillard, Christine; Nicolas, Jean-louis; Le Chevalier, Patrick; Lambert, Christophe; Le Boulay, Christine; Berthe, Franck; Haras, Dominique. |
| The emergence of new vibriosis in the European Atlantic coasts has been associated with mass mortalities of molluscs causing important economic losses. For examples, Vibrio carchariae, a bacteria already isolated from shark, has been associated with a severe Haliotis epizooty in hatchery. In oysters, Crass()strea gigas, a strain closely related to Vibrio splendidus is suspected to be associated with summer mortalities. |
| Tipo: Text |
Palavras-chave: Pathogenic vibrios; Bivales; Vibriosis; Bacteriology. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/acte-3287.pdf |
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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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| Lassudrie, Malwenn; Soudant, Philippe; Nicolas, Jean-louis; Miner, Philippe; Le Grand, Jacqueline; Lambert, Christophe; Le Goic, Nelly; Hegaret, Helene; Fabioux, Caroline. |
| The Pacific oyster Crassostrea gigas is an important commercial species cultured throughout the world. Oyster production practices often include transfers of animals into new environments that can be stressful, especially at young ages. This study was undertaken to determine if a toxic Alexandrium bloom, occurring repeatedly in French oyster beds, could modulate juvenile oyster cellular immune responses (i.e. hemocyte variables). We simulated planting on commercial beds by conducting a cohabitation exposure of juvenile, “specific pathogen-free” (SPF) oysters (naïve from the environment) with previously field-exposed oysters to induce interactions with new microorganisms. Indeed, toxic Alexandrium spp. exposures have been reported to modulate bivalve... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Alexandrium; Harmful algal blooms; Hemocyte; Microbial challenge. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00314/42523/41894.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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| Lassudrie, Malwenn; Soudant, Philippe; Nicolas, Jean-louis; Fabioux, Caroline; Lambert, Christophe; Miner, Philippe; Le Grand, Jacqueline; Petton, Bruno; Hegaret, Helene. |
| Blooms of toxic dinoflagellates can co-occur with mass mortality events associated with herpesvirus OsHV-1 μVar infection that have been decimating Pacific oyster Crassostrea gigas spat and juveniles every summer since 2008 in France. This study investigated the possible effect of a harmful dinoflagellate, Alexandrium catenella, a producer of Paralytic Shellfish Toxins (PSTs), upon the oyster spat–herpesvirus interaction. Oyster spat from a hatchery were challenged by cohabitation with oysters contaminated in the field with OsHV-1 μVar and possibly other pathogens. Simultaneously, the oysters were exposed to cultured A. catenella. Infection with OsHV-1 μVar and PST accumulation were measured after 4 days of experimental exposure. Exposure to Alexandrium... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; OsHV-1 mu Var; Harmful algal blooms; Alexandrium; Host-pathogen interaction; PST accumulation. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00269/38000/36101.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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| Registros recuperados: 49 | |
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