Consulta: creatorFacets:"Le Roux, Frédérique"
Registros recuperados: 17
Data/hora: 11/06/2024 03:37:17

Caractérisation de bactéries pathogènes, Vibrio splendidus, isolées de bivalves marins
Provedor de dados: 5
Autores: 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

First record of Marteilia sp in mussels Mytilus galloprovincialis in Croatia
Provedor de dados: 5
Autores: Zrncic, Snjevana; Le Roux, Frédérique; Oraic, Drazen; Sostaric, Branko; Berthe, Franck.
Marteiliosis is a disease of molluscs caused by Marteilia refringens in Europe and M. sydneyi in Australia. During routine examination of cultured mussels Mytilus galloprovinciallis in the northern Adriatic, the occurrence of Marteilia sp. was recorded with a prevalence of 5 %. This parasite was not detected in flat oysters reared in the same area. The affiliation of the detected parasite in M. galloprovinciallis was confirmed by in situ hybridization using a M. refringens probe, specific at the genus level. DNA of these infected mussels originating from the same area will be used to clarify the taxonomic position of this species within the genus Marteilia using a molecular approach.
Tipo: Text
Palavras-chave: Taxonomy; Detection; Mytilus galloprovincialis; Parasite; Marteilia maurini.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/publication-817.pdf

Taxonomie et virulence de vibrions pathogènes d'huîtres creuses Crassostrea gigas
Provedor de dados: 5
Autores: Le Roux, Frédérique.
As the emergence of new vibriosis in the European Atlantic coasts has been associated with mass mortalities of molluscs cuasing important economic losses, the project obectives are to provide knowledge and operational tools to evaluate the impact of vibriosis on farmed japenese oyster Crassostrea gigas. Facing the diversity of Vibrio species associated to bivalve disease outbreaks, the difficulties of identification and the detemrination of their pathogenic abilities we propose a double approach to correlate phenotype/geneotype of a bacteria with risk of disease : 1) by genotyping we will evaluate if specific strains are associated with disease. 2) by evaluating likely virulence mechanisms implicated in pathogenesis, we will characterise the genes...
Tipo: Text
Palavras-chave: Taxonomie; Marqueur génétique; Pathogène; Génotype; Phénotype; Crassotrea gigas; Huître; Vibrioses; Diagnostique.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/these-3699.pdf

Comparative analysis of Vibrio splendidus-related strains isolated during Crassostrea gigas mortality events
Provedor de dados: 5
Autores: 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

Characterization of Vibrio isolated from Crassostrea gigas spat suffering summer mortality outbreaks (slides)
Provedor de dados: 5
Autores: Gay, Melanie; Renault, Tristan; Le Roux, Frédérique.
The pathogens related to summer mortality outbreaks are a herpes virus and two bacterial strains one belonging to Vibrio splendidus biovar II and the other to Vibrio splendidus spp. However, the feature pathogen/opportunist of these strains is still unknown. Several strains belonging to the genus Vibrio have been identified as pathogen for different mollusk species. In the context of the French program Morest, experiments of cohabitation have been used to demonstrate the potential presence of a transmissible infectious agent in batches of oysters suffering from summer mortality outbreaks. More than one hundred Vibrio strains have been isolated from these experiments. These strains have been phenotypically and genotypically characterized. Their virulence...
Tipo: Text
Palavras-chave: Vibrio splendidus; Vibrio lentus; Crassostrea gigas; Summer; Spat; Pathogen; Disease transmission; Oyster culture; Mortality; Microbial contamination; Oysters.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/acte-3343.pdf

Two Vibrio splendidus related strains collaborate to kill Crassostrea gigas: taxonomy and host alterations
Provedor de dados: 5
Autores: Gay, Melanie; Renault, Tristan; Pons, Anne-marie; Le Roux, Frédérique.
For several years, strains phenotypically related to Vibrio splendidus have been associated with mortality outbreaks of molluscs. A former study on Crassostrea gigas demonstrated the genetic diversity of V splendidus strains associated with diseased animals. Another study suggested that different strains may act in an additive/synergistic way leading to higher C. gigas mortality rates. Here, a strain pair (31+32) was characterised at taxonomic and virulence levels. Using a polyphasic approach, these strains were confirmed to be V splendidus-related, without a clear discrimination between V. kanaloae and V. pomeroyi since hybridisation rates with both these strains were above 70%. Following experimental infection of C. gigas by injection in the adductor...
Tipo: Text
Palavras-chave: Histopathology; Molecular taxonomy; Agonism; Vibriosis.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/publication-2912.pdf

Epidémiologie moléculaire des espèces Marteilia en Europe
Provedor de dados: 5
Autores: Le Roux, Frédérique; Audemard, Corinne; Cochennec, Nathalie; Thebault, Anne; Berthe, Franck.
Responsible for massive epizootics, the Marteilia type parasites are very dangerous infectious agents for oysters. As a matter of fact, in France the spreading out of the parasitosis caused by Marteilia refringens disturbed dangerously the flat oyster, Ostrea edulis, production; destroying a large percentage of the farms on the Atlantic coast. The fight against marteiliose implies a good management of the contamination risk, that is to say the identification of the parasite(s), the characterization of the host(s), vector(s) or reservoir(s) and the understanding of the parasite's transmission mode.
Tipo: Text
Palavras-chave: Bivalves; Biologie Moléculaire; Marteilia refringens; Epidémiologie.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/acte-3271.pdf

Cg-TIMP, un inhibiteur de metalloproteinase isolé chez Crassostrea gigas : étude de son rôle dans la réparation des lésions et dans les mécanismes de défense
Provedor de dados: 5
Autores: Escoubas, Jean-michel; Montagnani, Caroline; Le Roux, Frédérique; De Lorgeril, Julien; Berthe, Franck; Bachere, Evelyne.
We isolated complementary DNA (Cg-TIMP) from Crassostrea gigas that codes for a protein highly homologous to vertebrate tissue inhibitors of metalloproteinases (TIMPs). In vertebrates, TIMPs are multifunctional proteins that play a key role in extracellular matrix metabolism. They are involved in physiological processes (e.g. embryonic development, damage repair, angiogenesis) and pathological processes (e.g. inflammatory reactions, cancer).
Tipo: Text
Palavras-chave: Proteine; Cg TIMP; ADN; Crassostrea gigas.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/acte-3268.pdf

Les parasites du groupe "Mikrocell" : Qui est qui?
Provedor de dados: 5
Autores: Cochennec, Nathalie; Le Roux, Frédérique; Berthe, Franck; Thebault, Anne.
Bonamiose, a disease caused by the protozoa Bonamia ostreae, has destroyed the flat oyster Ostrea edulis production, in France but also in Europe and in the United States since 1979. Another species of Bonamia has been monitored in New-Zealand, in Australia and lately in Chile. In Canada and Australia, two other parasites have been described in cupped oyster: Mikrocytos mackini and Mikrocytos roughleyi. All these small size protozoa are grouped under the name "Mikrocell". For most of them, light and electronic microscope descriptions have been realised. Based on those criteria, different taxonomic positions have been proposed. However, these analysis are still questioned today.
Tipo: Text
Palavras-chave: Bivalves; Haplosporidia; Parasites; Pathologie.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/acte-3270.pdf

Pipetman et bottes en caoutchouc à la recherche d'hôte(s) de Marteilia refringens
Provedor de dados: 5
Autores: Audemard, Corinne; Le Roux, Frédérique; Sauriau, Pierre-guy; Sautour, Benoît; Combes, C.; Coustau, C.; Blachier, Philippe; Berthe, Franck.
Over the last thirty years, the French production of flat oyster Ostrea edulis dropped from15,000 tons/year to 1,500 tons. Marteilia refringens, a parasite of the flat oyster's digestive gland, is partly responsible for this drop. The fight against this pathogen agent requires a better knowledge of its parasitic cycle. The main hypothesis is the existence of a heteroxenous cycle, that is to say a cycle involving more than one host. However, for thirty years this or these hosts have not been found, and the cycle of Marteilia refringens remains unknown.
Tipo: Text
Palavras-chave: Claires ostréicoles; Parasite; Détection; Biologie moléculaire; Marteilia refringens.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/acte-3272.pdf

Identification of a plasmid associated with virulence in Vibrio nigripulchritudo, a pathogen of the shrimp Litopenaeus stylirostris
Provedor de dados: 5
Autores: Reynaud, Yann; Saulnier, Denis; Mazel, Didier; Goarant, Cyrille; Le Roux, Frédérique.
Tipo: Text
Palavras-chave: Pathogenic vibrios; Pathology; Litopeneaus stylirostris; Vibrio nigripulchritudo.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3432.pdf

Could Mikrocytos roughleyi be a mis-classified haplosporidian?
Provedor de dados: 5
Autores: Cochennec, Nathalie; Le Roux, Frédérique; Berthe, Franck; Hine, Mike.
Bonamiosis refers to diseases of oysters caused by Bonamia ostreae in the Northern Hemisphere and Bonamia sp. in the Southern Hemisphere. Similarly, Mikrocytosis usually refers to diseases of oysters caused by Mikrocytos mackini on the west coast of Canada and Mikrocytos roughleyi on the east coast of Australia.
Tipo: Text
Palavras-chave: Oysters; Diseases; Pathology; Mikrocytos roughleyi.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/acte-3286.pdf

Needle in a haystack: involvement of the copepod Paracartia grani, in the life-cycle of the oyster pathogen Marteilia refringens
Provedor de dados: 5
Autores: Audemard, Corinne; Le Roux, Frédérique; Barnaud, Antoine; Collins, Catherine; Sautour, B; Sauriau, Pierre-guy; De Montaudouin, X; Coustau, C; Combes, C; Berthe, Franck.
Marteilia refringens is a major pathogen of the European flat oyster, Ostrea edulis Linnaeus. Since its description, the lifecycle of this protozoan parasite has eluded discovery. Attempts to infect oysters experimentally have been unsuccessful and led to the hypothesis of a complex life-cycle involving several hosts. Knowledge of this life-cycle is of central importance in order to manage oyster disease. However, the exploration of M. refringens life-cycle has been previously limited by the detection tools available and the tremendous number of species to be screened in enzootic areas. In this study, these two restrictions were circumvented by the use of both molecular detection tools and a mesocosm with low biodiversity. Screening of the entire fauna of...
Tipo: Text
Palavras-chave: Experimental transmission; In situ hybridization; PCR; Paracartia grani; Ostrea edulis; Marteilia refringens.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/2002/publication-2778.pdf

Nutrition and reproduction are key parameters in the interaction process leading to Crassostrea gigas oyster summer mortality in France
Provedor de dados: 5
Autores: Samain, Jean-francois; Degremont, Lionel; Soletchnik, Patrick; Ropert, Michel; Bedier, Edouard; Mazurie, Joseph; Mazurie, Joseph; Martin, Jean-louis; Moal, Jeanne; Mathieu, Michel; Pouvreau, Stephane; Lambert, Christophe; Escoubas, Jean-michel; Nicolas, Jean-louis; Le Roux, Frédérique; Renault, Tristan; Burgeot, Thierry; Bacher, Cedric; Boudry, Pierre.
Complex interactions between oyster, environment and pathogens were observed during the MOREST (2001-2005) project on summer mortality events of Crassostrea gigas oysters in France. The talk will show how nutrition level increasing reproductive intensity generates a risk for pathogen infection under synergistic effect of temperature and stress. Moreover, a genetic component is associated to specific reproductive performances and spawning behaviour. To better understand origin of such resistance or susceptibility to summer mortality, other characteristics as stress susceptibility, energy management and hemocyte activities of oysters from the two phenotypes were compared. This first comparison suggests interactions between stress, reproduction and defence...
Tipo: Text
Palavras-chave: Genetic; Pathologie; Mortality; Crassostrea gigas; Pacific oyster; Reproduction; Nutrition; Physilogy.
Ano: 2006
URL: https://archimer.ifremer.fr/doc/2006/acte-3467.pdf

Emergence de maladies chez les organismes d'intérêt aquacole : quelques scénarios illustrés d'exemples
Provedor de dados: 5
Autores: Saulnier, Denis; Reynaud, Yann; Arzul, Isabelle; Miossec, Laurence; Le Roux, Frédérique; Goarant, Cyrille.
According to the world organisation for animal health (OIE) an emerging disease is defined as a recently admitted serious illness, whose aetiology can, or not, have already been established, and which is likely to be propagated within a population or between populations, for example at the time of international exchanges of aquatic animals and/or products of aquatic animals. Even though the emerging diseases that affect human health have been much studied, those which affect marine organisms and species of aquaculture interest in particular are poorly documented. By restricting emergence to only infectious diseases, we aim at presenting in a non-exhaustive way some scenarios of the emergence of the diseases of aquacultured species by illustrating them with...
Tipo: Text
Palavras-chave: Cyprinus carpio; Ostrea edulis; Bonamia ostreae; Peneides; Vibrio nigripulchritudo; Herpesvirus; Agent pathogène.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2980.pdf

Validation of in situ hybridisation and histology assays for the detection of the oyster parasite Marteilia refringens
Provedor de dados: 5
Autores: Thebault, Anne; Bergman, S; Pouillot, R; Le Roux, Frédérique; Berthe, Franck.
An in situ hybridisation technique has been developed for the detection of infection in oysters with Marteilia refringens with particular emphasis on light infections or confirmation of suspected cases by means of histology. Although validation of new diagnostic methods is usually achieved by comparison with standard techniques, in our case the sensitivity and specificity of the standard (histology) had not previously been established. Another point to consider is that surveillance and monitoring frequently target populations displaying different levels of prevalence under different field conditions. The objective of our study was to evaluate the sensitivity and specificity values of in situ hybridisation and histology for the detection of M refringens,...
Tipo: Text
Palavras-chave: Ostrea edulis; Marteilia refringens; Latent models; Specificity; Sensitivity; Validation; Diagnostic.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-3624.pdf

Bilans depuis 1999 et évolution de la stratégie du REPAMO
Provedor de dados: 5
Autores: Thebault, Anne; Martin, Anne-genevieve; Pichot, Yves; Chollet, Bruno; Robert, Maeva; Le Coguic, Yvette; Tige, Gilbert; Hirata, Toshio; Mazurie, Joseph; Le Saux, Jean-claude; Masson, Nadine; Auby, Isabelle; Maurer, Daniele; Le Roux, Frédérique; Cochennec, Nathalie; Renault, Tristan; Berthe, Franck; Grizel, Henri.
The main objectives of the Mollusc Pathology Network (REPAMO) are to prevent introductions or outbreaks of infectious agents, prevent spread within a farm and especially from one farm to another, to study ways of decreasing the impact of infectious agent and to monitor the development of these pathogens in order to guarantee the health status of oysters exchanged with our commercial partners. On the whole, REPAMO's activities have not changed and include: - monitoring the development of diseases that have to be reported to authorities and carrying out analyses to classify zones: bonamiosis and marteiliosis; - baseline monitoring of farmed and wild populations of bivalve molluscs; - studying cases of abnormal mortality events; - controlling mollusc...
Tipo: Text
Palavras-chave: Mollusques; Réseau surveillance; Pathologie; REPAMO.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/acte-3265.pdf