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| Registros recuperados: 23 | |
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| Moreau, Pierrick; Moreau, Kevin; Morga, Benjamin; Tourbiez, Delphine; Travers, Marie-agnes; Rubinsztein, David; Renault, Tristan. |
| Mass mortality outbreaks of Pacific oysters, Crassostrea gigas, are reported in different areas around the world affecting seriously the shellfish aquaculture sector. Two pathogens are associated with these mortality outbreaks, ostreid herpesvirus 1 (OsHV-1) and Vibrio aestuarianus. In this contexte, a better knowledge is needed in terms of oyster immunity. For this purpose, as an important degradation pathway autophagy was investigated in the Pacific oysters. An in silico research of genes involved in autophagy using the C. gigas genome allowed identification of homologs of ATG1 and ATG8/LC3(Microtubule-associated protein 1A/1B-light chain 3). Gene expression and protein detection were analysed using real-time PCR and western blot, respectively. ATG1 and... |
| Tipo: Text |
Palavras-chave: Autophagy; Pacific oyster; Crassostrea gigas; OsHV-1; Vibrio aestuarianus. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00218/32876/31345.pdf |
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| Moreau, Pierrick; Moreau, Kevin; Segarra, Amelie; Tourbiez, Delphine; Travers, Marie-agnes; Rubinsztein, David C.; Renault, Tristan. |
| Recent mass mortality outbreaks around the world in Pacific oysters, Crassostrea gigas, have seriously affected the aquaculture economy. Although the causes for these mortality outbreaks appear complex, infectious agents are involved. Two pathogens are associated with mass mortality outbreaks, the virus ostreid herpesvirus 1 (OsHV-1) and the bacterium Vibrio aestuarianus. Here we describe the interactions between these 2 pathogens and autophagy, a conserved intracellular pathway playing a key role in innate immunity. We show for the first time that autophagy pathway is present and functional in Pacific oysters and plays an important role to protect animals from infections. This study contributes to better understand the innate immune system of Pacific... |
| Tipo: Text |
Palavras-chave: Autophagy; Crassostrea gigas; OsHV-1; Pacific oyster; Vibrio aestuarianus; ATG; Autophagy-related; Atg8-PE; Atg8-phosphatidylethenolamine; DNA; Deoxyribonucleic acid; Hpi; Hours postinfection; LC3-II; Cleaved; Lipidated and autophagosome-associated form of LC3; MAP1LC3A; B (LC3A; B); Microtubule-associated proteins 1 light chain 3 alpha. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00269/37989/36072.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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| Stavrakakis, Christophe; Papin, Mathias; Dupuy, Beatrice; Riou, Karen; Penisson, Christian; Nourry, Max; Hatt, Philippe-jacques; Buchet, Vincent; Palvadeau, Hubert. |
| L'eau qui alimente des structures d’élevage ou encore des plateformes expérimentales aquacoles (et potentiellement l’eau qui en est issue) peut être contaminée par des agents pathogènes infectant les coquillages, et plus particulièrement les huîtres, ou encore par des agents pathogènes entériques représentant un risque pour les consommateurs. Par ailleurs, la production possible d'huîtres tétraploïdes dans les installations d’élevage implique l’étude de solutions de traitement adaptées pour éviter tout rejet de gamètes, larves ou naissain d’animaux polyploïdes dans l'environnement. Le projet DESIMER a donc pour objectif d’étudier et de comparer différentes techniques de désinfection de l’eau de mer : la chloration, l’ozonation et le rayonnement UV afin de... |
| Tipo: Text |
Palavras-chave: Désinfection; Traitement de l’eau; Sous-produits; Vibrio aestuarianus; OsHV-1; Crassostrea gigas.; Disinfection; Water Treatment; By-products; Vibrio aestuarianus; OsHV-1; Crassostrea gigas.. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00376/48756/49141.pdf |
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| Degremont, Lionel; Maurouard, Elise; Godfrin, Yoann; Travers, Marie-agnes; Morga, Benjamin; Lamy, Jean-baptiste; Benabdelmouna, Abdellah. |
| Depuis 2012, le nombre de cas de mortalités d’huîtres creuses adultes (Crassostrea gigas) rapportés dans le cadre des réseaux de surveillance de l’Ifremer, et dans lesquels la bactérie Vibrio aestuarianus a été isolée, a fortement augmenté. Les objectifs de cette étude étaient (1) d’étudier la sensibilité des huîtres C. gigas à une infection à V. aestuarianus pour des lots diploïdes et triploïdes et (2) déterminer la réponse à la sélection pour une meilleure résistance à V. aestuarianus pour des huîtres C. gigas. Neuf stocks ont été utilisés, répartis en trois niveaux de sélection, chacun étant donc répliqué par trois pontes. Pour chaque stock, un lot diploïde (2n), un lot triploïde (3n_chim) produit par la rétention d’un globule polaire, et trois lots... |
| Tipo: Text |
Palavras-chave: Vibrio aestuarianus; OsHV-1; Sélection; Résistance; Triploïdes; Huître creuse; Crassostrea gigas; Vibrio aestuarianus; OsHV-1; Selective breeding; Disease resistance Pacific oyster; Crassostrea gigas; Triploids. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00404/51530/52140.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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| Engelsma, M; Roozenburg, I; Joly, Jean-pierre. |
| In summer 2006 an extensive mortality of Pacific oysters Crassostrea gigas occurred in Lake Grevelingen, the Netherlands. A sample of Pacific oysters was investigated for the presence of shellfish pathogens as potential causes of the mortality. Yellow-green lesions were observed in several oysters upon clinical inspection. Histopathology showed that 6 out of 36 oysters had a suspected bacterial infection, including 4 Nocardia-like infections. Two bacterial species, Vibrio aestuarianus and Nocardia crassostreae, were isolated from haemolymph samples and identified using PCR and sequencing of the 16S rRNA gene. This is the first isolation of N. crassostreae from shellfish in European waters. The near full-length 16S rRNA sequence of this Dutch Nocardia sp.... |
| Tipo: Text |
Palavras-chave: Summer mortalities; Ostrea edulis; Crassostrea gigas; Vibrio aestuarianus; Nocardia crassostreae. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4568.pdf |
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| Castagnet, Sophie. |
| Depuis une quinzaine d'années, des mortalités massives d'huîtres creuses Crassostrea gigas, sont observées sur le littoral français durant la période estivale. Des études ont démontré que les mortalités sont plurifactorielles et qu'elles sont la résultante d'interactions entre l'environnement, l'huître (physiologie et génétique) et certains agents infectieux. Durant ce stage, les interactions entre l'huître creuse et deux bactéries de genre Vibrio (Vibrio splendidus et Vibrio aestuarianus), fréquemment associées aux mortalités, ont été étudiées, afin de tenter de comprendre le lien entre les facteurs de l'hôte (origine génétique et physiologie de la reproduction) et les vibrions (production d'un facteur de virulence), pouvant impacter la sensibilité de... |
| Tipo: Text |
Palavras-chave: Ecophysiologie; Génétique; Huître creuse; Crassostrea gigas; Vibrio splendidus; Vibrio aestuarianus; Microbiologie. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00033/14442/11741.pdf |
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| Barbosa-solomieu, Valerie; Renault, Tristan; Travers, Marie-agnes. |
| Massive mortality outbreaks in cultured bivalves have been reported worldwide and they have been associated with infection by a range of viral and bacterial pathogens. Due to their economic and social impact, these episodes constitute a particularly sensitive issue in Pacific oyster (Crassostrea gigas) production. Since 2008, mortality outbreaks affecting C. gigas have increased in terms of intensity and geographic distribution. Epidemiologic surveys have lead to the incrimination of pathogens, specifically OsHV-1 and bacteria of the Vibrio genus, in particular Vibrio aestuarianus. Pathogen diversity may partially account for the variability in the outcome of infections. Host factors (age, reproductive status…) including their genetic background that has... |
| Tipo: Text |
Palavras-chave: Pacific oyster; Spat; OsHV-1; Vibrio aestuarianus; Mortality. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00274/38534/37051.pdf |
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| Garnier, Matthieu; Labreuche, Yannick; Nicolas, Jean-louis. |
| Eleven Vibrio isolates invading the hemolymph of live and moribund oysters (Crassostrea gigas) collected in the field and from a hatchery in France, were characterized by a polyphasic approach. Phylogenetic analysis of 16S rRNA, gyrB and toxR genes indicated high homogeneity between these strains and the Vibrio aestuarianus type strain (ATCC35048(T)), and confirmed previous 16S rRNA analysis. In contrast, DNA:DNA hybridization was from 61% to 100%, while phenotypic characters and virulence tests showed a large diversity between the strains. Nevertheless, several common characters allowed the isolates to be distinguished from the reference strain. On the basis of several distinct phenotypic characteristics, it is proposed to establish two subspecies within... |
| Tipo: Text |
Palavras-chave: Polyphasic approach; Summer mortalities; Crassostrea gigas; Pathogen; French isolates; Vibrio aestuarianus. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4961.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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| 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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| Azema, Patrick; Travers, Marie-agnes; Benabdelmouna, Abdellah; Degremont, Lionel. |
| French production of the Pacific cupped oyster, Crassostrea gigas, is currently threatened by two pathogens, OsHV-1 and V. aestuarianus. While oysters selected for their higher resistance to OsHV-1 are now available for the industry, the impact of V. aestuarianus on such oysters is unknown, especially for triploids. In addition, experimental infection has used the virus or the bacteria alone, but there have been no investigations of dual exposure to these pathogens. This study is the first report of single or dual exposure in spat (Spat1 and Spat2), juvenile and adult naïve oysters. For each of the two stocks evaluated, unselected oysters and oysters selected for their higher resistance to OsHV-1 infection were tested, as well as their triploid siblings of... |
| Tipo: Text |
Palavras-chave: Vibrio aestuarianus; OsHV-1; Dual exposure; Ploidy; Selection; Crassostrea gigas. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00347/45835/45918.pdf |
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| Registros recuperados: 23 | |
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