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| Registros recuperados: 48 | |
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| Martenot, Claire; Segarra, Amelie; Baillon, Laury; Faury, Nicole; Houssin, Maryline; Renault, Tristan. |
| Immunohistochemistry (IHC) assays were conducted on paraffin sections from experimentally infected spat and unchallenged spat produced in hatchery to determine the tissue distribution of three viral proteins within the Pacific oyster, Crassostrea gigas. Polyclonal antibodies were produced from recombinant proteins corresponding to two putative membrane proteins and one putative apoptosis inhibitor encoded by ORF 25, 72, and 87, respectively. Results were then compared to those obtained by in situ hybridization performed on the same individuals, and showed a substantial agreement according to Landis and Koch numeric scale. Positive signals were mainly observed in connective tissue of gills, mantle, adductor muscle, heart, digestive gland, labial palps, and... |
| Tipo: Text |
Palavras-chave: OsHV-1; Viral proteins; Crassostrea gigas. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00326/43697/43124.pdf |
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| Azema, Patrick; Travers, Marie-agnes; Benabdelmouna, Abdellah; Degremont, Lionel. |
| French production of the Pacific cupped oyster, Crassostrea gigas, is currently threatened by two pathogens, OsHV-1 and V. aestuarianus. While oysters selected for their higher resistance to OsHV-1 are now available for the industry, the impact of V. aestuarianus on such oysters is unknown, especially for triploids. In addition, experimental infection has used the virus or the bacteria alone, but there have been no investigations of dual exposure to these pathogens. This study is the first report of single or dual exposure in spat (Spat1 and Spat2), juvenile and adult naïve oysters. For each of the two stocks evaluated, unselected oysters and oysters selected for their higher resistance to OsHV-1 infection were tested, as well as their triploid siblings of... |
| Tipo: Text |
Palavras-chave: Vibrio aestuarianus; OsHV-1; Dual exposure; Ploidy; Selection; Crassostrea gigas. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00347/45835/45918.pdf |
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| Degremont, Lionel; Maurouard, Elise; Godfrin, Yoann; Travers, Marie-agnes; Morga, Benjamin; Lamy, Jean-baptiste; Benabdelmouna, Abdellah. |
| Depuis 2012, le nombre de cas de mortalités d’huîtres creuses adultes (Crassostrea gigas) rapportés dans le cadre des réseaux de surveillance de l’Ifremer, et dans lesquels la bactérie Vibrio aestuarianus a été isolée, a fortement augmenté. Les objectifs de cette étude étaient (1) d’étudier la sensibilité des huîtres C. gigas à une infection à V. aestuarianus pour des lots diploïdes et triploïdes et (2) déterminer la réponse à la sélection pour une meilleure résistance à V. aestuarianus pour des huîtres C. gigas. Neuf stocks ont été utilisés, répartis en trois niveaux de sélection, chacun étant donc répliqué par trois pontes. Pour chaque stock, un lot diploïde (2n), un lot triploïde (3n_chim) produit par la rétention d’un globule polaire, et trois lots... |
| Tipo: Text |
Palavras-chave: Vibrio aestuarianus; OsHV-1; Sélection; Résistance; Triploïdes; Huître creuse; Crassostrea gigas; Vibrio aestuarianus; OsHV-1; Selective breeding; Disease resistance Pacific oyster; Crassostrea gigas; Triploids. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00404/51530/52140.pdf |
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| Cordier, Clémence; Stavrakakis, Christophe; Morga, Benjamin; Degrémont, Lionel; Voulgaris, Alexandra; Bacchi, Alessia; Sauvade, Patrick; Coelho, Franz; Moulin, Philippe. |
| Among water treatment processes, ultrafiltration is known to be efficient for the elimination of micro-organisms (bacteria and viruses). In this study, two pathogens were targeted, a bacterium, Vibrio aestuarianus and a virus, OsHV-1, with the objective to produce high quality water from seawater, in the case of shellfish productions. The retention of those microorganisms by ultrafiltration was evaluated at labscale. In the case of OsHV-1, the protection of oysters was validated by in vivo experiments using oysters spat and larvae, both stages being highly susceptible to the virus. The oysters raised using contaminated seawater which was then subsequently treated by ultrafiltration, had similar mortality to the negative controls. In the case of V.... |
| Tipo: Text |
Palavras-chave: Ultrafiltration; Biosecurisation; Pathogen retention; Sea water; OsHV-1; Shellfish production. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00634/74576/74466.pdf |
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| Agnew, M. Victoria; Friedman, Carolyn S.; Langdon, Christopher; Divilov, Konstantin; Schoolfield, Blaine; Morga, Benjamin; Degremont, Lionel; Dhar, Arun K.; Kirkland, Peter; Dumbauld, Brett; Burge, Colleen A.. |
| Pacific oysters, Crassostrea gigas, are one of the most productive aquaculture species in the world. However, they are threatened by the spread of Ostreid herpesvirus-1 (OsHV-1) and its microvariants (collectively “µvars”), which cause mass mortalities in all life stages of Pacific oysters globally. Breeding programs have been successful in reducing mortality due to OsHV-1 variants following viral outbreaks; however, an OsHV-1-resistant oyster line does not yet exist in the United States (US), and it is unknown how OsHV-1 µvars will affect US oyster populations compared to the current variant, which is similar to the OsHV-1 reference, found in Tomales Bay, CA. The goals of this study were to investigate the resistance of C. gigas juveniles produced by the... |
| Tipo: Text |
Palavras-chave: OsHV-1; Mu vars; Oyster; Virus; Tolerance; Virulence; QPCR. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00665/77739/79862.pdf |
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| Pernet, Fabrice; Gachelin, Sonia; Stanisière, Jean-yves; Petton, Bruno; Fleury, Elodie; Mazurié, Joseph. |
| The intertidal zone is characterized by a sharp vertical gradient of environmental stress, which structures species distribution and their interactions. Few studies, however, have examined the influence of tidal height on host–pathogen interactions. Here, we investigated how the tidal height influence outbreak of the Ostreid herpesvirus type 1 (OsHV-1) affecting the Pacific oyster. A volunteer network composed of 20 oyster growers monitored the survival of 28 batches of oysters during an epizootic event in Southern Brittany, France. Oysters were spat from wild collection or hatchery production. The sampling sites were spread over a 150-km2 area with a tidal height ranging from 0.98 to 2.90 m. Concomitantly, we followed survival of oyster spats in relation... |
| Tipo: Text |
Palavras-chave: Aquaculture; Citizen science; Marine epidemiology and health; OsHV-1; Risk analysis. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00491/60271/63981.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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| Pernet, Fabrice; Lagarde, Franck; Le Gall, Patrik; Roque D'Orbcastel, Emmanuelle. |
| We present the first large-scale, high-resolution spatial and temporal pattern of disease mortality caused by Ostreid herpesvirus 1 (OsHV-1) that has affected Pacific oyster Crassostrea gigas in France every year since 2008, in relation to local farm use. Mortality was monitored in healthy oyster spat deployed at 106 locations in the Thau Mediterranean lagoon during the epizootic that occurred in spring 2011. We conducted a field survey of farming practices in the areas where the sentinel oysters were placed before the epizootic. We found that the risk of disease mortality in sentinel oysters was higher within the bivalve farming area than outside it, suggesting that the infection pressure is much higher in areas with intensive farming activity. The risk... |
| Tipo: Text |
Palavras-chave: Aquaculture; Epidemiology; OsHV-1; Shellfish farming. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00201/31248/30662.pdf |
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| Leprêtre, Maxime; Faury, Nicole; Segarra, Amelie; Claverol, Stéphane; Degremont, Lionel; Palos-ladeiro, Mélissa; Armengaud, Jean; Renault, Tristan; Morga, Benjamin. |
| Massive mortality outbreaks affecting Pacific oysters (Crassostrea gigas) spat/juveniles are often associated with the detection of a herpesvirus called ostreid herpesvirus type 1 (OsHV-1). In this work, experimental infection trials of C. gigas spat with OsHV-1 were conducted using two contrasted Pacific oyster families for their susceptibility to viral infection. Live oysters were sampled at 12, 26, and 144 h post infection (hpi) to analyze host-pathogen interactions using comparative proteomics. Shotgun proteomics allowed the detection of seven viral proteins in infected oysters, some of them with potential immunomodulatoy functions. Viral proteins were mainly detected in susceptible oysters sampled at 26 hpi, which correlates with the mortality and... |
| Tipo: Text |
Palavras-chave: Proteomics; Interactions; Antiviral response; OsHV-1; Pacific oysters. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00669/78075/80307.pdf |
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| Soletchnik, Patrick; Mazurie, Joseph; Allain, Gwenhael; Bedier, Edouard; Benabdelmouna, Abdellah; Blin, Jean-louis; Bouquet, Anne-lise; Cochet, Hélène; Degremont, Lionel; Gaussem, Florian; Gervasoni, Erika; Glize, Philippe; Petton, Bruno; Roussel, Pierre-yves; Pernet, Fabrice. |
| This paper summarizes knowledge about relations between husbandry practices and oyster spat mortalities since 2008 in France. These relations are strictly analyzed from a panel of experiments set on the shore (in outdoor experiments) by Ifremer teams and technical institutes all over French coasts. Results show some practices are able to reduce spat mortality with some influencing factors relevant of spat quality (sanitary status, natural or genetic selection) or husbandry practices. Spat “free” of virus is able to survive up to 90% when it is isolated and confined in ponds or nursery, during an epidemic crisis. When outbreaks occurred in oyster beds, natural or nursery spat died in almost same proportions. In 2010, some studies conducted in Mediterranean... |
| Tipo: Text |
Palavras-chave: Surmortalité; Naissain; Huître creuse; OsHV-1; Pratiques culturales; Mortality; Spat; Cupped oyster; Crassostrea gigas; OsHV-1; Cultural practices. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00032/14280/25847.pdf |
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| Pernet, Fabrice; Tamayo, David; Petton, Bruno. |
| Mortalities of oyster seed of Crassostrea gigas associated with ostreid herpes virus OsHV-1 μVar have been observed in many oyster producing countries since 2008. The objective of this study was to further investigate whether low temperature treatments can offer a viable option to mitigate oyster mortalities. An experiment was set-up to further evaluate the effect of low temperature treatments (10 and 13°C vs. 21°C) and their duration (6 d to 83 d) on the survival of oysters previously infected with OsHV-1 μVar by means of exposure to field conditions in areas where mortalities were occurring. Average survival of oysters infected with OsHV-1μVar was 71% after 83 d at low temperatures compared to only 23% in controls maintained at 21°C. During... |
| Tipo: Text |
Palavras-chave: Bivalve; Disease; OsHV-1; Oyster; Temperature; Virus. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00259/37047/35555.pdf |
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| Degremont, Lionel; Nourry, Max; Maurouard, Elise. |
| The ostreid herpesvirus 1 (OsHV-1) is one of the major pathogens affecting the Pacific oyster Crassostrea gigas, and numerous mortality outbreaks have been observed worldwide. We report the first results of our experimental breeding program using mass selection focused on survival and resistance to OsHV-1 after four generations of selection for two lines. These lines originated from two stocks of adult wild oysters sampled from the Marennes-Oléron Bay in 2008. Each line was spawned in February 2009 to produce the base populations. Both lines were then either protected from OsHV-1 or tested in the field in 2009 where they were exposed to OsHV-1. For each line during 2010 to 2013, one generation per year was produced using either the survivors of the... |
| Tipo: Text |
Palavras-chave: Survival; Crassostrea gigas; Realized heritability; Selection response; OsHV-1; Disease resistance. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00266/37751/36064.pdf |
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| Martenot, Claire; Faury, Nicole; Morga, Benjamin; Degremont, Lionel; Lamy, Jean-baptiste; Houssin, Maryline; Renault, Tristan. |
| Viral entry mechanisms of herpesviruses constitute a highly complex process which implicates several viral glycoproteins and different receptors on the host cell surfaces. This initial infection stage was currently undescribed for Ostreid herpes virus 1 (OsHV-1), a herpesvirus infecting bivalves including the Pacific oyster, Crassostrea gigas. To identify OsHV-1 glyproteins implicated in the attachment of the virus to oyster cells, three viral putative membrane proteins, encoded by ORF 25, 41, and 72, were selected and polyclonal antibodies against these targets were used to explore first interactions between the virus and host cells. In addition, effects of dextran sulfate, a negative charged sulfated polysaccharide, were investigated on OsHV-1 infection.... |
| Tipo: Text |
Palavras-chave: OsHV-1; Antiviral antibodies; Dextran sulfate; Interaction; Crassostrea gigas; Infection. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00501/61273/64847.pdf |
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| Moreau, Pierrick. |
| The thesis work is part of the very current issue on mass mortality outbreaks affecting Pacific oyster, C. gigas, spat and juveniles and questions about the involvement of pesticides in this phenomenon. The first part of this thesis was devoted to study the effects of pesticides on hemocyte parameters in the Pacific oyster (in vitro and in vivo). The immunomodulator effect of selected pesticides (alone or in mixture) has been explored principally through flow cytometry. The second part concerned the study of the effects of a pesticides mixture on OsHV-1 itself. No direct effects have been reported on the viral particles in presence of the pollutants. Moreover, pesticide effects on Pacific oysters were also explored through experimental pathology assays... |
| Tipo: Text |
Palavras-chave: Pacific oyster; Pesticides; OsHV-1; Autophagy; Immunity; Hemocyte; Pathology. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00226/33740/32149.pdf |
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| Azema, Patrick; Maurouard, Elise; Lamy, Jean-baptiste; Degremont, Lionel. |
| Mortality associated with ostreid herpesvirus 1 (OsHV-1) has significantly impacted Crassostrea gigas farmers all around the world. Although selective breeding programs to improve OsHV-1 resistance can significantly reduce the mortality rate below 20%, husbandry practices have also been one way to limit or decrease mortality. The main objectives of this study were to describe the influence of two husbandry practices on OsHV-1-induced mortality in C. gigas spat and how different family lines respond to husbandry practices to gain a better understanding of the potential benefits of breeding management as a tool to adapt to improved practices. The first analysis investigated the importance of the size of C. gigas when challenged with OsHV-1 for the first... |
| Tipo: Text |
Palavras-chave: Mortality; Crassostrea gigas; Size; OsHV-1; Growing height. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00366/47717/47758.pdf |
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| Bai, Chang-ming; Morga, Benjamin; Rosani, Umberto; Shi, Jie; Li, Chen; Xin, Lu-sheng; Wang, Chong-ming. |
| Ostreid herpesvirus 1 (OsHV-1) is an important pathogen associated with mass mortalities of cultivated marine mollusks worldwide. Since no cell line allows OsHV-1 replication in vitro, it is difficult to isolate enough high-purity viral DNA for High-Throughput Sequencing (HTS). We developed an efficient approach for the enrichment of OsHV-1 DNA for HTS with long-range PCR. Twenty-three primer pairs were designed to cover 99.3% of the reference genome, and their performances were examined on ten OsHV-1 infected samples. Amplicon mixtures from six successfully amplified samples were sequenced with Illumina platform, and one of them (ZK0118) was also sequenced with the PacBio platform. PacBio reads were assembled into 2 scaffolds compared to 9−68 scaffolds... |
| Tipo: Text |
Palavras-chave: Long-range PCR; OsHV-1; High-throughput sequencing; Evolution; Diversity. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00464/57566/64184.pdf |
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| Registros recuperados: 48 | |
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