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| Registros recuperados: 73 | |
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| Saulnier, Denis; De Decker, Sophie; Haffner, Philippe. |
| Because Vibrio aestuarianus is known to cause serious infections in Pacific oyster Crassostrea gigas, a real-time PCR assay was developed targeting the dnaJ gene of this bacterium. Only V. aestuarianus strains isolated from C. gigas mortality events in different geographic areas and the reference strain tested positive, whereas no amplification products was obtained with type strains belonging to 23 other species of Vibrio. Sensitivity and reproducibility of the method were assessed using either seawater or oyster homogenate samples spiked with one V aestuarianus strain. All these samples were stored at -20 degrees C in order to mimic retrospective or grouped natural sample analysis without quantification bias due to prolonged freezing. Analysis of... |
| Tipo: Text |
Palavras-chave: V. aestuarianus; Vibrio; Taqman; Real time PCR; Pathogen; Oyster; Crassostrea gigas. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6447.pdf |
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| Cardona, Emilie; Saulnier, Denis; Lorgeoux, Benedicte; Chim, Liet; Gueguen, Yannick. |
| This study compares the antioxidant and antimicrobial transcriptional expression of blue shrimps reared according to two different systems, BioFloc Technology (BFT) and Clear sea Water (CW) and their differential responses when facing an experimental sublethal hydrogen peroxide stress. After 30 days of rearing, juvenile shrimps were exposed to H2O2 stress at a concentration of 30 ppm during 6 hours. The oxidative stress caused by H2O2 was examined in the digestive glands of the shrimp, in which antioxidant enzyme (AOE) and antimicrobial peptide (AMP) gene expression were analysed by quantitative real-time PCR. Results showed that rearing conditions did not affect the expression of genes encoding AOEs or AMPs. However, H2O2 stress induced a differential... |
| Tipo: Text |
Palavras-chave: Biofloc; Shrimps; Antimicrobial peptides; Antioxidant enzymes. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00270/38116/36269.pdf |
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| Gueguen, Yannick; Saulnier, Denis; Santini, Adrien; Magre, Kevin; Garen, Pierre; Bernagout, Solene; Nohl, Marine; Bouisset, Patrick; Helme, Herehia; Planes, Serge; Le Moullac, Gilles. |
| This study was designed to identify in the pearl oyster Pinctada margaritifera, used as a bio-accumulator, molecular biomarkers for the presence of heavy metals in the lagoon environment. Pearl oysters were exposed to 2 concentrations (1 and 10 μg L− 1) of cadmium (Cd) and chromium (Cr) compared to a control. Twelve target genes encoding proteins potentially involved in the response to heavy metal contamination with antioxidant, detoxification or apoptosis activities were selected. P. margaritifera accumulated Cd but not Cr, and mortality was related to the amount of Cd accumulated in tissues. In response to Cd-Cr contamination, metallothionein (MT) was significantly up-regulated by Cd-Cr at both concentrations, while 7 others (SOD, CAT, GPX, GSTO, GSTM,... |
| Tipo: Text |
Palavras-chave: Pinctada margaritifera; French Polynesia; Cadmium; Chromium; Gene expression; Metallothionein. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00376/48707/49146.pdf |
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| De Decker, Sophie; Normand, Julien; Saulnier, Denis; Pernet, Fabrice; Castagnet, Sophie; Boudry, Pierre. |
| Several Vibrio species are known to be pathogenic to the Pacific oyster Crassostrea gigas. Survival varies according to pathogen exposure and high mortality events usually occur in summer during gametogenesis. In order to study the effects of gametogenetic status and ploidy (a factor known to affect reproduction allocation in oysters) on vibriosis survival, we conducted two successive experiments. Our results demonstrate that a common bath challenge with pathogenic Vibrio splendidus and Vibrio aestuarianus on a mixture of mature, spawning and non-mature oysters can lead to significant mortality. Previous bath challenges, which were done using only non-mature oysters, had not produced mortality. Immunohisto-chemical analyses showed the affinity of Vibrio... |
| Tipo: Text |
Palavras-chave: Experimental vibriosis; Crassostrea gigas; Vibrio; Survival distribution function; Triploidy; Reproductive effort. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00030/14108/11368.pdf |
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| Bardon-albaret, Agnes; Gasset, Eric; Teissier, Alexandre; Teiri, W; Maamaatuaiahutapu, M; David, R; Tayale, Alexandre; Belliard, Corinne; Levy, Peva; Basset, Caline; Sicard, Julien; Magre, Kevin; Herne, Antoine; Reverter, Myriam; Sasal, Pierre; Coves, Denis; Saulnier, Denis. |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00281/39246/37819.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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| Rouze, Heloise; Lecellier, Gael; Saulnier, Denis; Berteaux-lecellier, Veronique. |
| Coral disease outbreaks have increased over the last three decades, but their causal agents remain mostly unclear (e.g., bacteria, viruses, fungi, protists). This study details a 14-month-long survey of coral colonies in which observations of the development of disease was observed in nearly half of the sampled colonies. A bimonthly qPCR method was used to quantitatively and qualitatively evaluate Symbiodinium assemblages of tagged colonies, and to detect the presence of Vibrio spp. Firstly, our data showed that predisposition to disease development in general, and, more specifically, infection by Vibrio spp. in Acropora cytherea depended on which clades of Symbiodinium were harbored. In both cases, harboring clade D rather than A was beneficial to the... |
| Tipo: Text |
Palavras-chave: Coral disease; Dynamic; Resistance; Symbiodinium assemblages; Vibrio. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00307/41848/41080.pdf |
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| Joubert, Caroline; Linard, Clementine; Le Moullac, Gilles; Soyez, Claude; Saulnier, Denis; Teaniniuraitemoana, Vaihiti; Ky, Chin-long; Gueguen, Yannick. |
| In this study, we analyzed the combined effect of microalgal concentration and temperature on the shell growth of the bivalve Pinctada margaritifera and the molecular mechanisms underlying this biomineralization process. Shell growth was measured after two months of rearing in experimental conditions, using calcein staining of the calcified structures. Molecular mechanisms were studied though the expression of 11 genes encoding proteins implicated in the biomineralization process, which was assessed in the mantle. We showed that shell growth is influenced by both microalgal concentration and temperature, and that these environmental factors also regulate the expression of most of the genes studied. Gene expression measurement of shell matrix protein... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00210/32095/30535.pdf |
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| Simon-colin, Christelle; Gueguen, Yannick; Bachere, Evelyne; Kouzayha, Achraf; Saulnier, Denis; Gayet, Nicolas; Guezennec, Jean. |
| Cultured pearls are the product of grafting and rearing of Pinctada margaritifera pearl oysters in their natural environment. Nucleus rejections and oyster mortality appear to result from bacterial infections or from an inappropriate grafting practice. To reduce the impact of bacterial infections, synthetic antibiotics have been applied during the grafting practice. However, the use of such antibiotics presents a number of problems associated with their incomplete biodegradability, limited efficacy in some cases, and an increased risk of selecting for antimicrobial resistant bacteria. We investigated the application of a marine antimicrobial peptide, tachyplesin, which is present in the Japanese horseshoe crab Tachypleus tridentatus, in combination with... |
| Tipo: Text |
Palavras-chave: Pearl oyster; Exopolysaccharide; Tachyplesin; Antimicrobial. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00275/38599/37128.pdf |
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| Faury, Nicole; Saulnier, Denis; Thompson, F; Gay, Melanie; Swings, J; Leroux, Frederique. |
| Polyphasic analysis of five new Vibrio isolates originating from the haernolymph of diseased cultured oysters is described. The new isolates were closely related to Vibrio splendidus, having 98 % 16S rRNA gene sequence similarity. gyrB phylogenetic analysis, fluorescent amplified-fragment length polymorphism (FAFLP) fingerprinting and DNA-DNA hybridization experiments clearly showed that the new isolates form a tight genomic group that is different from the currently known Vibrio species. It is proposed to accommodate these isolates in a novel species, Vibrio crassostreae sp. nov. (type strain LGP 7(T) =LMG 22240(T)=Clp 108327(T)). Phenotypic and chemotaxonomic features that differentiate V. crassostreae from other known Vibrio species include arginine... |
| Tipo: Text |
Palavras-chave: Identification; Vibrio; Crasssotrea gigas; Ostreiculture. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-591.pdf |
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| Le Roux, Frederique; Goubet, A; Thompson, F; Faury, Nicole; Gay, Melanie; Swings, J; Saulnier, Denis. |
| Polyphasic analysis of four new Vibrio isolates originating from the haemolymph of diseased cultured oysters is described. The new isolates were closely related to Vibrio splendidus, having 98 % 16S rRNA gene sequence similarity. Phylogenetic analysis based on DNA gyrase subunit B (gyrB), RNA polymerase Quo factor (rpoD), replication origin-binding protein (rctB) and transmembrane regulatory protein (toxR) genes, fluorescent amplified fragment length polymorphism and DNA-DNA hybridization experiments clearly showed that the new isolates form a tight genomic group that is different from the currently known Vibrio species. It is proposed that these new isolates should be accommodated in a novel species, Vibrio gigantis sp. nov. Phenotypic features that... |
| Tipo: Text |
Palavras-chave: Vibrio gigantis; Haemoplymph; Disease; Crassostrea gigas; Oyster culture. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-792.pdf |
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| De Decker, Sophie; Saulnier, Denis. |
| The understanding of reciprocal interactions between Crassostrea gigas and Vibrio sp., whether these be virulent or avirulent, is vital for the development of methods to improve the health status of cultured oysters. We describe an original non-invasive experimental infection technique using cohabitation, designed to explore these interactions. Using real-time PCR techniques we examined the dynamics of virulent and avirulent Vibrio sp. in oyster hemolymph and tank seawater, and made a parallel study of the expression of four genes involved in oyster immune defense: Cg-BPI, Cg-EcSOD, Cg-IκB, Cg-TIMP. No mortality occurred in control animals, but oysters put in cohabitation for 2–48 h with animals previously infected by two Vibrio pathogens suffered... |
| Tipo: Text |
Palavras-chave: Oyster-Vibrio interactions; Pathogenesis; Immune response; Non-invasive experimental challenge; Real-time PCR. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00025/13604/10681.pdf |
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| Registros recuperados: 73 | |
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