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| Registros recuperados: 225 | |
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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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| Gervais, Ophelie; Renault, Tristan; Arzul, Isabelle. |
| Bonamia ostreae has been associated with the decline of flat oyster Ostrea edulis populations in some European countries. This obligatory intracellular parasite persists and multiplies into hemocytes. Previous in vitro experiments showed that apoptosis is activated in hemocytes between 1 h and 4 h of contact with the parasite. The flat oyster uses the apoptosis pathway to defend against B. ostreae. However, the parasite might be also able to modulate this response in order to survive in its host. In order to investigate this hypothesis the apoptotic response of the host was evaluated using flow cytometry, transmission electron microscopy and by measuring the response of genes involved in the apoptotic pathway after 4 h. In parallel, the parasite response... |
| Tipo: Text |
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| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00454/56540/58246.pdf |
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| Morga, Benjamin; Arzul, Isabelle; Faury, Nicole; Segarra, Amelie; Chollet, Bruno; Renault, Tristan. |
| Bonamiosis due to the parasite Bonamia ostreae is a disease affecting the flat oyster Ostrea edulis. B. ostreae is a protozoan, affiliated to the order of haplosporidia and to the cercozoan phylum. This parasite is mainly intracellular, infecting haemocytes, cells notably involved in oyster defence mechanisms. Suppression subtractive hybridisation (SSH) was carried out in order to identify oyster genes differentially expressed during an infection of haemocytes with B. ostreae. Forward and reverse banks allowed obtaining 1104 and 1344 clones respectively, among which 391 and 480 clones showed a differential expression between both tested conditions (haemocytes alone versus haemocytes in contact with parasites). ESTs of interest including genes involved in... |
| Tipo: Text |
Palavras-chave: Bonamia ostreae; Protozoan; Ostrea edulis; Flat oyster; Haemocytes; Gene expression; Suppression subtractive hybridisation. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00018/12879/9828.pdf |
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| Saulnier, Denis; Pepin, Jean-francois; Guesdon, Stephane; Degremont, Lionel; Faury, Nicole; Haffner, Philippe; Renault, Tristan; Travers, Marie-agnes; Tourbiez, Delphine; Geairon, Philippe; Le Moine, Olivier; Seugnet, Jean-luc; Soletchnik, Patrick. |
| This study aims to improve understanding of causes of mortalities in oyster Crassostrea gigas in pertuis charentais related to environmental parameters and the kinetics of targeted infectious agents, such as bacteria Vibrio splendidus (group ) and V. aestuarianus and Ostreid herpesvirus OsHV-1. Two sampling campaigns were carried out on the site of Agnas in 2009 and 2010, before, during or following mortality events of spat from March to September. The approach is to detect and quantify in short time step infectious agents from tissues of farmed oysters placed on rack and in various samples taken nearby: native oysters and other species (wild mussels and barnacles), seawater and sediment. With physical and chemical automatic probes placed on the site,... |
| Tipo: Text |
Palavras-chave: Huître creuse; Crassostrea gigas; Mortalité; Virus herpès; Vibrions; Environnement; Pertuis Charentais; Pacific oyster; Crassostrea gigas; Mortality; Herpes virus; Vibrios; Environment; Pertuis Charentais. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00058/16920/14400.pdf |
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| Smolarz, Kasia; Renault, Tristan; Soletchnik, Patrick; Wolowicz, Macciek. |
| A flow cytometry protocol was applied for the detection of neoplasia in Macoma balthica L. from the Gulf of Gdansk (Baltic Sea, Poland). A simple method, based on an osmotic shock, was used to permeabilise gill cells. The cytometric pattern of normal clams consisted of 2 peaks, a major peak B and a smaller peak C. The cytometric pattern of affected clams consisted of 2 peaks named B' and C'. Two parameters were used to define the stages of abnormalities in M. balthica clams based on the percentage of cells in peaks B, C, B' and C' and on the ratio between the fluorescence value of peaks B, C, B' and C' in all individuals. Three stages of neoplasia were clearly distinguished by flow cytometry considering peak C'. Stage 1 was characterised by a major... |
| Tipo: Text |
Palavras-chave: Baltic Sea; Macoma balthica; Neoplasia; Cytogenetics; Histology; Flow cytometry. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-2918.pdf |
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| Degremont, Lionel; Lamy, Jean-baptiste; Pepin, Jean-francois; Travers, Marie-agnes; Renault, Tristan. |
| The Pacific oyster, Crassostrea gigas, is the most important commercial oyster species cultivated in the world. Meanwhile, the ostreid herpesvirus 1 (OsHV-1) is one of the major pathogens affecting the Pacific oyster, and numerous mortality outbreaks related to this pathogen are now reported worldwide. To assess the genetic basis of resistance to OsHV-1 infection in spat C. gigas and to facilitate breeding programs for such a trait, if any exist, we compared the mortality of half- and full-sib families using three field methods and a controlled challenge by OsHV-1 in the laboratory. In the field, three methods were tested: (A) one family per bag; (B) one family per small soft mesh bag and all families inside one bag; (C) same as the previous methods but... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00269/38066/36178.pdf |
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| Morga, Benjamin; Renault, Tristan; Faury, Nicole; Arzul, Isabelle. |
| Bonamiosis due to the parasite Bonamia ostreae has been associated with massive mortality in flat oyster stocks in Europe. Control of the disease currently relies on disease management practices and transfer restriction. Previously, massal selections based on survival to challenge to infection with B. ostreae have been applied to produce flat oyster families with resistant progeny. In an attempt to understand the molecular mechanisms involved in disease resistance, differentially expressed sequence tags between resistant and wild Ostrea edulis haemocytes, both infected with the parasite, were identified using suppression subtractive hybridisation. Expression of seven ESTs has been studied using quantitative reverse-transcriptase PCR. The base-line... |
| Tipo: Text |
Palavras-chave: Protozoan; Ostrea edulis; Flat oyster; Transcriptomic; Gene expression. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00071/18218/15790.pdf |
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| Alfjorden, A; Areskog, M; Bruno, D; Carnegie, R; Cheslett, D; Feist, S; Ford, S; Jones, S; Lillehaug, Atle; Madsen, L; Renault, Tristan; Ruane, N; Vennerstrom, P. |
| The ICES Working Group on Pathology and Diseases of Marine Organisms (WGPDMO) provides annual reviews of national reports on the disease status of wild and farmed fish and molluscs in the ICES area. In 2004, the group published a first report collating this information from 1998-2002. This second report aims to provide an update on the status of the major diseases described in the original report and also to provide an overview of new diseases which have emerged since the previous report was published. |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00585/69731/67620.pdf |
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| 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 |
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| Sauvage, Christopher; Pepin, Jean-francois; Lapegue, Sylvie; Boudry, Pierre; Renault, Tristan. |
| Ostreid herpes virus 1 (OsHV-1) infections, notably reported in Europe and the USA, are closely associated with significant mortalities of the Pacific oyster, Crassostrea gigas, especially during its early stages of life. In summer 2006, we monitored mortality by strict daily verification of three full-sib families of oysters reared under common conditions. We quantified OsHV-1 using real-time PCR in dead and living individuals during and after a mortality event. Mortality events were severe and brief, but significantly different between tested families (cumulative mortality ranging from 1.2 to 49%). Real-time PCR assays revealed different viral DNA loads in dead individuals from different families (P < 0.001). Moreover, the mean level of infection... |
| Tipo: Text |
Palavras-chave: Viral DNA quantification; Real time PCR; OsHV 1; Mortality; Crassostrea gigas. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6265.pdf |
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| Garcia, Celine; Thebault, Anne; Degremont, Lionel; Arzul, Isabelle; Miossec, Laurence; Robert, Maeva; Chollet, Bruno; Francois, Cyrille; Joly, Jean-pierre; Ferrand, Sylvie; Kerdudou, Nolwenn; Renault, Tristan. |
| Since its molecular characterisation, Ostreid herpesvirus 1 (OsHV-1) has been regularly detected in Crassostrea gigas in France. Although its pathogenicity was demonstrated on larval stages, its involvement during mortality outbreaks at the juvenile stage was highly suspected but not evidenced. To investigate mortality outbreaks, the French National Network for Surveillance and Monitoring of Mollusc Health (REPAMO) carried out two surveys in juvenile C. gigas. The first survey lasted from 1998 to 2006 and was an epidemiological inquiry occurring when oyster farmers reported mortality outbreaks. The second survey, a longitudinal one, was set up in 1998 to complete the network observations on OsHV-1. Data analysis showed a specific pattern of mortality... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00040/15110/12572.pdf |
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| Renault, Tristan; Bouquet, Anne Lise; Maurice, Julien-thomas; Lupo, Coralie; Blachier, Philippe. |
| number of bivalve species worldwide, including the Pacific oyster, Crassostrea gigas, have been affected by mass mortality events associated with herpesviruses, resulting in significant losses. A particular herpesvirus was purified from naturally infected larval Pacific oysters, and its genome was completely sequenced. This virus has been classified as Ostreid herpesvirus 1 (OsHV-1) within the family Malacoherpesviridae. Since 2008, mass mortality outbreaks among C. gigas in Europe have been related to the detection of a variant of OsHV-1 called µVar. Additional data are necessary to better describe mortality events in relation to environmental-parameter fluctuations and OsHV-1 detection. For this purpose, a single batch of Pacific oyster spat was deployed... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00207/31871/30320.pdf |
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| Segarra, Amelie; Baillon, Laury; Tourbiez, Delphine; Benabdelmouna, Abdellah; Faury, Nicole; Bourgougnon, Nathalie; Renault, Tristan. |
| Since 2008, massive mortality outbreaks associated with OsHV-1 detection have been reported in Crassostrea gigas spat and juveniles in several countries. Nevertheless, adult oysters do not demonstrate mortality in the field related to OsHV-1 detection and were thus assumed to be more resistant to viral infection. Determining how virus and adult oyster interact is a major goal in understanding why mortality events are not reported among adult Pacific oysters. Dual transcriptomics of virus-host interactions were explored by real-time PCR in adult oysters after a virus injection. Thirty-nine viral genes and five host genes including MyD88, IFI44, IkB2, IAP and Gly were measured at 0.5, 10, 26, 72 and 144 hours post infection (hpi). No viral RNA among the 39... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00213/32414/30887.pdf |
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| Moreau, Pierrick; Burgeot, Thierry; Renault, Tristan. |
| Pesticides are frequently detected in estuaries among the pollutants found in estuarine and coastal areas and may have major ecological consequences. They could endanger organism growth, reproduction or survival. In the context of high mortality outbreaks affecting Pacific oysters, Crassostrea gigas, in France since 2008, it appears of importance to determine the putative effects of pesticides on oyster susceptibility to infectious agents. Massive mortality outbreaks reported in this species, mainly in spring and summer, may suggest an important role played by the seasonal use of pesticides and freshwater input in estuarine areas where oyster farms are frequently located. To understand the impact of some pesticides detected in French waters, their effects... |
| Tipo: Text |
Palavras-chave: Immunity; Hemocytes; Pesticides; Pacific oyster; Crassostrea gigas; Flow cytometry; Bivalve. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00144/25555/23700.pdf |
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| Moreau, Pierrick; Faury, Nicole; Burgeot, Thierry; Renault, Tristan. |
| Since 2008, mass mortality outbreaks have been reported in all French regions producing Pacific oysters, and in several Member States of the European Union. These mass mortality events of Pacific oysters are related to OsHV-1 infection. They occur during spring and summer periods leaving suspect the quality of the marine environment and the role of seasonal use of pesticides associated with the arrival of freshwater in oyster rearing areas. Pesticides have been also detected in French coastal waters, especially in areas of oyster production. Using PMA real-time PCR we showed that a mixture of 14 pesticides has no effect on the integrity of virus capsids from viral suspension in the conditions tested. A contact of oysters with this pesticide mixture was... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00273/38405/36730.pdf |
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| Registros recuperados: 225 | |
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