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| Registros recuperados: 19 | |
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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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| Luna-acosta, Andrea; Saulnier, Denis; Pommier, Mylene; Haffner, Philippe; De Decker, Sophie; Renault, Tristan; Thomas-guyon, Helene. |
| Phenoloxidases (POs) are a group of copper proteins including tyrosinase, catecholase and laccase. In several insects and crustaceans, antibacterial substances are produced through the PO cascade, participating in the direct killing of invading microorganisms. However, although POs are widely recognised as an integral part of the invertebrate immune defence system, experimental evidence is lacking that these properties are conserved in molluscs, and more particularly in the Pacific oyster Crassostrea gigas. In the present study, Vibrio splendidus LGP32 and Vibrio aestuarianus 02/041 growths were affected, after being treated with C. gigas haemocyte lysate supernatant (HLS), and either a common substrate of POs, l-3,4-dihydroxyphenylalanine (l-DOPA), to... |
| Tipo: Text |
Palavras-chave: Phenoloxidases; Antibacterial activity; Vibrio; Bivalve; Immunity. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00045/15598/13001.pdf |
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| Saulnier, Denis; De Decker, Sophie; Haffner, Philippe; Cobret, Laetitia; Robert, Maeva; Garcia, Celine. |
| A 4-year bacteriological survey (2003-2007) of four molluscs cultivated in France and faced with mortality episodes was performed by the French shellfish pathology network. The more abundant bacteria isolated during 92 mortality episodes, occurring mainly in Pacific oyster Crassostrea gigas, were identified by genotyping methods. It allowed us both to confirm the representativeness of Vibrio splendidus and Vibrio aestuarianus bacterial strains and to identify both a large number of Vibrio harveyi-related strains mainly detected during 2007 oyster mortality outbreaks and to a lesser extent bacterial strains identified as Shewanella colwelliana. Because metalloprotease has been reported to constitute a virulence factor in a few Vibrio strains pathogenic for... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6974.pdf |
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| Goyard, Emmanuel; Goarant, Cyrille; Ansquer, Dominique; Brun, Pierre; De Decker, Sophie; Dufour, Robert; Galinie, C; Peignon, Jean-marie; Pham, Dominique; Vourey, Elodie; Harache, Yves; Patrois, Jacques. |
| Two populations of the Latin American shrimp Penaeus (Litopenaeus)stylirostris domesticated in Hawaii and in New Caledonia were previously shown to be genetically differentiated and proven highly inbred. In New Caledonia, where different Vibriosis affect shrimp production and antibiotic use is banned in growing ponds, the Hawaiian population was introduced to increase the allelic variability available for local shrimp farmers and start a genetic improvement program. Growth and survival rates of the two pure populations and the two-way F-1-hybrids obtained by breeding Hawaiian animals with New Caledonian animals were assessed in several simple experiments (earthen ponds, floating cages and experimental infection challenges) during two years on two... |
| Tipo: Text |
Palavras-chave: Vibriosis; Survival; Growth; Penaeus Litopenaeus stylirostris; Shrimp; Cross breeding; Genetic improvement. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4316.pdf |
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| De Decker, Sophie. |
| The New-Caledonian shrimp industry is based on the controlled reproduction of the shrimp Litopenaeus stylirostris, a species which was introduced in the 80s. The major difficulty to which the industry has been faced for 10 years is the occurrence of the “Syndrome 93”, which corresponds to mortality phases when the temperature falls down in April-May-June. This mortality is associated to the pathogenic bacteria Vibrio penaecida. An experiment of genetic selection based on the criterion ofsurvival to Syndrome 93 has been conducted at the Laboratory of Aquaculture of New Caledonia. The 3rd selected generation had demonstrated very encouraging results (survival rates improved by around 20% in experimental infections with V. penaeicida). These results have not... |
| Tipo: Text |
Palavras-chave: Amélioration génétique; L. stylirostris; Résistance; Syndrome 93; Genetic improvement; L. stylirostris; Disease resistance; Syndrome 93. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/00204/31527/29943.pdf |
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| De Decker, Sophie; Reynaud, Yann; Saulnier, Denis. |
| The aim of that studywas to explore the hypothesis that a quorumsensingmechanismmodulatesmetalloprotease gene expression of two Vibrio species pathogenic for oyster, at intraspecific (Vibrio splendidus) and interspecific (V. splendidus affecting V. aestuarianus) levels. Metalloprotease activities (Vsm for V. splendidus LGP32 and Vam for V. aestuarianus 02/041) and growth curves obtained by real-time PCR assay revealed cell density-dependent metalloprotease inductions triggered between 12 h and 16 h of culture. A quorum sensing assay was then developed using a conditioned medium prepared from supernatant of a mutant strain of V. splendidus LGP32 unable to produce metalloprotease. Specific real-time qPCR assays targeting metalloprotease genes vsm and vam... |
| Tipo: Text |
Palavras-chave: Quorum sensing; Crassostrea gigas; Vibrio; Metalloprotease; Gene expression. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00124/23539/21381.pdf |
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| Goarant, Cyrille; Reynaud, Yann; Ansquer, Dominique; De Decker, Sophie; Merien, Fabrice. |
| In a previous study, we demonstrated the existence of an emerging cluster of Vibrio nigripulchritudo that proved to be associated with shrimp mortality events in New Caledonia. Using sequence polymorphisms evidenced in this previous MultiLocus Sequence Typing study, we developed two new quantitative PCR assays permitting the detection and quantification of V. nigripulchritudo at the genospecies level using SYBR Green I chemistry and at the emerging cluster level using Fluorescence Resonance Energy Transfer technology with hybridization probes. The use of this molecular diagnostic tool evidenced the colonization of the shrimp pond ecosystem by the pathogenic cluster at least at the onset of the disease. This new tool will allow better investigation of the... |
| Tipo: Text |
Palavras-chave: Shrimp; Cluster specific; Vibrio; Pathogen; Mariculture; Real time PCR. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2729.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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| De Decker, Sophie. |
| The bacteria of the Vibrio genus are one of the most abundant groups in the aquatic ecosystems. Two species of vibrios, Vibrio splendidus and V. Aestuarianus, have been associated, in some cases, to mortality in flat oyster Crassostrea gigas farms, most of the time during the summer period. This doctoral thesis studies the Vibrio-host interaction and their modulations according to the host's pathogenic virulence and its genetic, physiologic and immunitary parameters. These factors will be characterised by in vitro and in vivo approaches (experimental infection). The characterization of contrasted genetic families according to their sensitivity to these vibrios will enable the implementation of new improvement strategies in oyster farms (prophylactic... |
| Tipo: Text |
Palavras-chave: Immunologie; Physiologie; Paramètres génétiques; Virulence; Oyster; Crassostrea gigas; Pathogène; Vibrio. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/acte-3431.pdf |
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| De Decker, Sophie; Normand, Julien; Duperthuy, Marylise; Boudry, Pierre; Saulnier, Denis. |
| Rearing of Crassostrea gigas is the most economically important aquaculture activity in France. Bacteria belonging to Vibrio genus constitute one of the most abundant bacterial group in marine ecosystems. Two Vibrio species, V. splendidus and V. aestuarianus, were associated with many cases of mortality events in reared C. gigas spat and juvenile oysters, commonly during summer. This summer mortality syndrome has been extensively documented as the result of complex interactions between pathogens, host and environmental conditions. This work aims to study the Vibrio-host interactions and their modulations according to the virulence of pathogens and the genetic and/or physiological parameters of the host. These factors will be characterized by in vitro and... |
| Tipo: Text |
Palavras-chave: Genetic; Pathogens; Interaction; Vibrio; Crassostrea gigas; Oyster. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/acte-3430.pdf |
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| Goyard, Emmanuel; Ansquer, Dominique; Brun, Pierre; De Decker, Sophie; Dufour, Robert; Goarant, Cyril; Patrois, Jacques; Peignon, Jean; Pham, Dominique. |
| Selective breeding of shrimp for viral resistance is established for species like L. vannamei and L. stylirostris. However, selection for bacterial infection resistance is not documented. In New Caledonia, "Syndrome 93" is a vibriosis that affects cultured shrimps during the cool season with survival from 15 to 30%. Current practises for breeders rearing at low densities do not improve the resistance of the offsprings mainly because selection pressures for "Syndrome 93" are low. Even after the fifth generation, survival improvement is not significant. |
| Tipo: Text |
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| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/00117/22848/20658.pdf |
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| Goarant, Cyrille; Reynaud, Yann; Ansquer, Dominique; De Decker, Sophie; Saulnier, Denis; Leroux, Frederique. |
| A collection of 57 isolates of Vibrio nigripulchritudo from either diseased or healthy shrimp and from shrimp farms environment was studied in order to gain a better understanding of the epidemiology of this pathogen, notably isolated from two distinct shrimp disease complexes. Molecular typing using two different techniques, arbitrarily primed PCR (AP-PCR) and multi-locus sequence typing (MLST), studied together with experimental pathology data allowed a relevant epidemiological insight into this possibly emerging pathogen. Additionally, results obtained with the two molecular typing techniques were congruent and allowed discriminating the strains associated with the "Summer Syndrome" from strains isolated from other contexts, especially the other shrimp... |
| Tipo: Text |
Palavras-chave: Virulence; Epidemiology; Typing; MLST; AP PCR; Mariculture; Vibriosis. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1913.pdf |
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| De Decker, Sophie. |
| L’élevage des crevettes pénéides a connu un développement spectaculaire à l’échelle mondiale depuis les années soixante-dix, en particulier grâce à la maîtrise de l’ensemble du cycle biologique en captivité de plusieurs espèces d’intérêt aquacole (Aquacop, 1979). Elle a en effet permis de s’affranchir de l’approvisionnement aléatoire en juvéniles de pêche et en géniteurs sauvages, et par voie de conséquence de domestiquer ces espèces, c'est-à-dire de les sélectionner spontanément pour de meilleures aptitudes à l’élevage. Cette évolution est similaire à celle de filières piscicoles. Cependant les pathologies infectieuses représentent un frein important au développement ultérieur de ces activités. De manière générale, une pathologie infectieuse est la... |
| Tipo: Text |
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| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/00204/31528/29944.pdf |
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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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| Goarant, Cyrille; Ansquer, Dominique; Herlin, Jose; Domalain, David; Imbert, Frederic; De Decker, Sophie. |
| The Summer Syndrome is a new shrimp disease that has been affecting a shrimp growout farm in New Caledonia since end of 1997. It was recognized to be caused by a systemic vibriosis due to Vibrio nigripulchritudo. This new disease turned out almost immediately enzootic in the shrimp farm involved and has affected all its crops ever since. Since the year 2000, V. nigripulchritudo strains have been found in several shrimp farms, although Summer Syndrome is still limited to one particular area, affecting, since 2003, two adjoining farms. As part of a multidisciplinary research program, a high-frequency survey was carried out during the summer 2002-2003 in two shrimp farms: one affected farm and another one in which pathogenic strains could be isolated but... |
| Tipo: Text |
Palavras-chave: Epidemiology; Vibrio; Diseases and their control; Shrimp. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1110.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: 19 | |
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