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| Registros recuperados: 54 | |
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| Pepin, Jean-francois; Soletchnik, Patrick; Le Moine, Olivier; Polsenaere, Pierre; Genauzeau, Sylvie; Robert, Stephane; Grizon, James; Seugnet, Jean-luc; Schmitt, Anne; Chabirand, Jean-michel; Tourbiez, Delphine; Travers, Marie-agnes; Guesdon, Stephane. |
| We report in this work data of two independent studies carried out in the Pertuis Charentais for which a link might exist? A 30-years local time series study of hydro-climatic variations in water temperature and salinity, which show a significant warming of the water masses in the Marennes Oleron bay (+ 1.5 °C) associated with a significant drop ( > -15%) of freshwater intakes by nearby rivers. In this changing local climate context several major epizootics have appeared, severely affecting farmers and the production of Pacific oysters and mussels, from the first French shellfish-producing department (catching and growing, Agreste, 2012). Following massive mortality event of blue mussels in 2014, a specific study (MORBLEU) is conducted, trying to... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00415/52697/53567.pdf |
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| Lupo, Coralie; Travers, Marie-agnes; Tourbiez, Delphine; Barthélémy, Clement; Beaunée, Gaël; Ezanno, Pauline. |
| Vibrio aestuarianus is a bacterium related to mortality outbreaks in Pacific oysters, Crassostrea gigas, in France, Ireland, and Scotland since 2011. Knowledge about its transmission dynamics is still lacking, impairing guidance to prevent and control the related disease spread. Mathematical modeling is a relevant approach to better understand the determinants of a disease and predict its dynamics in imperfectly observed pathosystems. We developed here the first marine epidemiological model to estimate the key parameters of V. aestuarianus infection at a local scale in a small and closed oyster population under controlled laboratory conditions. Using a compartmental model accounting for free-living bacteria in seawater, we predicted the infection dynamics... |
| Tipo: Text |
Palavras-chave: Marine epidemiology; Parameter estimation; Compartmental model; ABC method; Global sensitivity analysis; Basic reproduction number R-0; Crassostrea gigas; Oyster mortality. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00495/60652/64148.pdf |
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| Allain, Thibault; Chaouch, Soraya; Thomas, Myriam; Travers, Marie-agnes; Valle, Isabelle; Langella, Philippe; Grellier, Philippe; Polack, Bruno; Florent, Isabelle; Bermudez-humaran, Luis G.. |
| Giardia duodenalis is a protozoan parasite responsible for giardiasis, a disease characterized by intestinal malabsorption, diarrhea and abdominal pain in a large number of mammal species. Giardiasis is one of the most common intestinal parasitic diseases in the world and thus a high veterinary, and public health concern. It is wellestablished that some probiotic bacteria may confer protection against this parasite in vitro and in vivo and we recently documented the implication of bile-salt hydrolase (BSH)-like activities from strain La1 of Lactobacillus johnsonii as mediators of these effects in vitro. We showed that these activities were able to generate deconjugated bile salts that were toxic to the parasite. In the present study, a wide collection of... |
| Tipo: Text |
Palavras-chave: Giardia duodenalis; Lactobacilli; Lactobacillus johnsonii; Lactobacillus gasseri; Probiotics; Bile salt hydrolases. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00424/53569/54417.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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| Lupo, Coralie; Dutta, Bhagat Lal; Petton, Sebastien; Ezanno, P; Tourbiez, Delphine; Travers, Marie-agnes; Pernet, Fabrice; Bacher, Cedric. |
| Vibrio aestuarianus infection in oyster populations causes massive mortality, resulting in losses for oyster farmers. Such dynamics result from host-pathogen interactions and contagion through water-borne transmission. To assess the spatiotemporal spread of V. aestuarianus infection and associated oyster mortality at a bay scale, we built a mathematical model informed by experimental infection data at 2 temperatures and spatially dependent marine connectivity of oyster farms. We applied the model to a real system and tested the importance of each factor using a number of modelling scenarios. Results suggest that introducing V. aestuarianus in a fully susceptible adult oyster population in the bay would lead to the mortality of all farmed oysters over 6 to... |
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Palavras-chave: Basic reproduction number; Crassostrea gigas; Hydrodynamics; Oyster disease; Sensitivity analysis; Vibrio aestuarianus. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00662/77459/79114.pdf |
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| Falaise, Charlotte; Francois, Cyrille; Travers, Marie-agnes; Morga, Benjamin; Haure, Joel; Tremblay, Rejean; Turcotte, Francois; Pasetto, Pamela; Gastineau, Romain; Hardivillier, Yann; Leignel, Vincent; Mouget, Jean-luc. |
| The search for novel compounds of marine origin has increased in the last decades for their application in various areas such as pharmaceutical, human or animal nutrition, cosmetics or bioenergy. In this context of blue technology development, microalgae are of particular interest due to their immense biodiversity and their relatively simple growth needs. In this review, we discuss about the promising use of microalgae and microalgal compounds as sources of natural antibiotics against human pathogens but also about their potential to limit microbial infections in aquaculture. An alternative to conventional antibiotics is needed as the microbial resistance to these drugs is increasing in humans and animals. Furthermore, using natural antibiotics for... |
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Palavras-chave: Biological activity; Antimicrobial; Antibacterial; Antifungal; Antiviral; Biological activity; Haslea; Microalgae; Sustainable aquaculture. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00349/46052/45719.pdf |
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| Travers, Marie-agnes; Mersni Achour, Rachida; Haffner, Philippe; Tourbiez, Delphine; Cassone, Anne-laure; Morga, Benjamin; Doghri, Ibtissem; Garcia, Celine; Renault, Tristan; Fruitier-arnaudin, Ingrid; Saulnier, Denis. |
| Nine dominant bacterial isolates were obtained from different batches of Crassostrea gigas spat experiencing high mortality rates in a French experimental hatchery/nursery in 2007. Using phenotypic analysis combined with multilocus sequence analysis, the isolates were shown to be genetically close to the Vibrio tubiashii type strain. Based on (1) analyses of the recA gene sequences; (2) the results of DNA–DNA hybridization assays between 07/118 T2 (LMG 27884 = CECT 8426), which is a representative strain, and the V. tubiashii type strain (69%); and (3) phenotypic traits, the bacteria were classified in a group close to American V. tubiashii strain. Its virulence (70% of mortalities) and the toxicity of the extracellular products of 07/118 T2 was... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas Pathogenicity Extracellular products Polyphasic approach; Real time PCR. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00189/30028/28743.pdf |
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| Azema, Patrick; Lamy, Jean-baptiste; Boudry, Pierre; Renault, Tristan; Travers, Marie-agnes; Degremont, Lionel. |
| Background In France, two main diseases threaten Pacific oyster production. Since 2008, Crassostrea gigas spat have suffered massive losses due to the ostreid herpesvirus OsHV-1, and since 2012, significant mortalities in commercial-size adults have been related to infection by the bacterium Vibrio aestuarianus. The genetic basis for resistance to V. aestuarianus and OsHV-1 and the nature of the genetic correlation between these two traits were investigated by using 20 half-sib sire families, each containing two full-sib families. For each disease, controlled infectious challenges were conducted using naïve oysters that were 3 to 26 months old. In addition, siblings were tested under field, pond and raceway conditions to determine whether laboratory... |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00372/48350/48518.pdf |
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| Benabdelmouna, Abdellah; Saunier, Alice; Ledu, Christophe; Travers, Marie-agnes; Morga, Benjamin. |
| In the context of the abnormal mass mortality of mussels in France since 2014, Flow CytoMetry (FCM) was used in 2015 and 2016 to study the DNA content and cell cycle characteristics of hemic circulating cells collected from 2000 mussels. The mussels were sampled from 12 wild and cultivated blue mussels stocks distributed along the French Atlantic coast from the south Brittany to Pertuis Charentais areas. During these surveys, various genetic abnormalities were frequently detected, and ploidy characteristics revealed contrasting profiles that corresponded to respective contrasting sanitary status, i.e. healthy mussels with high cytogenetic quality (HCQ) versus diseased mussels with low cytogenetic quality (LCQ). In the present work, FCM and hemocytology... |
| Tipo: Text |
Palavras-chave: Mussels; Hemocytes; Flow cytometry; Hemocytology; Cytogenetic quality; Neoplasia. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00455/56623/58443.pdf |
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| Mersni Achour, Rachida; Imbert-auvray, Nathalie; Huet, Valerie; Ben Cheick, Yosra; Faury, Nicole; Doghri, Ibtissem; Rouatbi, Sonia; Bordenave, Stéphanie; Travers, Marie-agnes; Saulnier, Denis; Fruitier-arnaudin, Ingrid. |
| Extracellular products (ECPs) of the French V. tubiashii strain 07/118 T2 were previously reported to be toxic for the Pacific oyster Crassostrea gigas. In this study we now assessed host cellular immune responses and bacterial potential effectors by which these ECPs can be associated with host damages. The adhesion capacity (28% inhibition) and phagocytosis ability (56% inhibition) of oyster hemocytes were the main functions affected following in vitro contact between hemocytes and V. tubiashii ECPs. This may be linked to the demonstration of the capability of ECPs to cleave various cellular substrates as oyster collagen. Moreover, a strong metalloproteolytic activity was recorded with general (azocasein) and specific (ADAM) substrates and characterized... |
| Tipo: Text |
Palavras-chave: ECPs; Oyster immune responses; Thermolysin-metalloprotease; Mass spectroscopy; ADAM substrate; Vibrio. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00211/32203/30642.pdf |
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| Destoumieux‐garzón, Delphine; Canesi, Laura; Oyanedel, Daniel; Travers, Marie-agnes; Charrière, Guillaume; Pruzzo, Carla; Vezzulli, Luigi. |
| n the marine environment, bivalve mollusks constitute habitats for bacteria of the Vibrionaceae family. Vibrios belong to the microbiota of healthy oysters and mussels, which have the ability to concentrate bacteria in their tissues and body fluids, including the hemolymph. Remarkably, these important aquaculture species respond differently to infectious diseases. While oysters are the subject of recurrent mass mortalities at different life stages, mussels appear rather resistant to infections. Thus, Vibrio species are associated to the main diseases affecting the worldwide oyster production. Here we review the current knowledge on Vibrio‐bivalve interaction in oysters (Crassostrea sp.) and mussels (Mytilus sp.). We discuss the transient versus stable... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00628/74032/73360.pdf |
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| Pepin, Jean-francois; Benabdelmouna, Abdellah; Degremont, Lionel; Guesdon, Stephane; Le Moine, Olivier; Morga, Benjamin; Bierne, Nicolas; Travers, Marie-agnes; Robert, Stephane; Soletchnik, Patrick. |
| Depuis 2014, des épisodes de mortalité anormale affectent les cheptels mytilicoles tant adultes que juvéniles. Dès l’année 2015, une première année d’étude a été réalisée au travers de l’action MORBLEU (Mortalité des moules Bleues). Elle a été menée dans les Pertuis charentais et la baie de Bourgneuf. Dans ce même contexte, elle a été reconduite en 2016 afin de poursuivre l’analyse des données collectées en 2015, renouveler une campagne d’étude et d’observation in situ, formuler des hypothèses autour de facteurs favorisants ces épisodes de mortalité de moules, développer des essais permettant de tester ces hypothèses dans le futur et produire des lots de moules pour ces essais et pour caractériser le potentiel adaptatif des animaux face aux épisodes de... |
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Palavras-chave: Moules; Mytilus edulis; Facteurs environnementaux; Mortalité; Equilibre microbien; Populations; Qualité cytogénétique; Anomalies hémocytaires; Expression de gènes; Physiologie. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00391/50288/50978.pdf |
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| Pepin, Jean-francois; Bouget, Jean-francois; Chabirand, Jean-michel; Chasselin, Leo; Costes, Louis; Grizon, James; Lejolivet, Aurore; Le Noc, Sandrine; Palvadeau, Hubert; Schmitt, Anne; Seugnet, Jean-luc; Soletchnik, Patrick; Travers, Marie-agnes; Tourbiez, Delphine; Guesdon, Stephane. |
| Since 2014 in France, in Charente maritime and Vendée, farmed and stocks of blue mussels experienced strong mortality events. In this context, the « MORBLEU » research project (DPMA-Ifremer agreement) was initiated to explore potentially aggravating factors, associated or correlated with mortality of mussels. Here, the work is to study biotic factors in mussels environment, looking for describe diversity and evolution of microbial communities (water column) before, during and after mortality events using NGS technology (metabarcoding) for environmental DNA analysis. We present, sampling strategy used from 2015 to 2018, Material & Methods and some preliminary results. |
| Tipo: Text |
Palavras-chave: MORBLEU; Moules; Mortalité; ADN environnemental; EDNA; Metabarcoding; Communautés microbiennes. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00505/61664/65579.pdf |
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| Registros recuperados: 54 | |
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