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| Registros recuperados: 57 | |
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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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| Danic-tchaleu, Gwenaelle; Heurtebise, Serge; Morga, Benjamin; Lapegue, Sylvie. |
| Background Because of its typical architecture, inheritance and small size, mitochondrial (mt) DNA is widely used for phylogenetic studies. Gene order is generally conserved in most taxa although some groups show considerable variation. This is particularly true in the phylum Mollusca, especially in the Bivalvia. During the last few years, there have been significant increases in the number of complete mitochondrial sequences available. For bivalves, 35 complete mitochondrial genomes are now available in GenBank, a number that has more than doubled in the last three years, representing 6 families and 23 genera. In the current study, we determined the complete mtDNA sequence of Ostrea edulis, the European flat oyster. We present an analysis of features of... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00045/15628/13031.pdf |
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| Morga, Benjamin; Arzul, Isabelle; Chollet, Bruno; Gagnaire, Beatrice; Renault, Tristan. |
| Bonamiosis is a disease affecting the flat oyster Ostrea edulis and caused by the protozoa parasite Bonamia ostreae, which is affiliated to the haplosporidia order and the cercozoa phylum. This parasite is mainly intracellular, infecting haemocytes, circulating cells playing an important role in the oyster's defence mechanisms. Even though the parasite's cycle has not been completely understood yet, direct infection from infected oysters to healthy oysters is possible. This leads us to think that there is no intermediary host in the cycle. Very little data on the parasite's infection mechanisms or the host's defence mechanisms is available. In order to better comprehend the Bonamia ostreae / host interaction, some flat oyster's haemocytes have been put in... |
| Tipo: Text |
Palavras-chave: Intéraction; Hémocytes; Ostrea edulis; Bonamia ostreae; Parasitologie. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/acte-3366.pdf |
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| Morga, Benjamin. |
| The history of French oyster culture shows very well how fragile this farming is to stock overexploitation and diseases. The production of flat oyster, Ostrea edulis, fell dramatically after the appearance of two parasitic diseases: arteiliosis and bonamiosis. The curative means against bonamiosis (Bonamia ostreae) are restricted and imply a good knowledge of the parasite's life cycle and of its interaction with its host. Studying the expression of the parasite's and the host's genes during the infection seems essential in providing new adapted measures in order to maintain, if not relaunch the flat oyster culture. In this context, this thesis aims to understand the flat oyster-parasite interactions, and especially, the molecular basis of the resistance to... |
| Tipo: Text |
Palavras-chave: Biologie moléculaire; Gene; Parasite; Huîtres; Ostrea edulis. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/acte-3369.pdf |
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| Arzul, Isabelle; Bond, Celine; Gagnaire, Beatrice; Morga, Benjamin; Chollet, Bruno; Ferrand, Sylvie; Robert, Maeva; Renault, Tristan. |
| Bonamiosis due to the intrahaemocytic protistan parasite Bonamia ostreae is a European endemic disease affecting the flat oyster, Ostrea edulis. After its first description in June 1979ı in Brittany, the parasite rapidly spread to all French oyster farming areas and in other European countries through transfers of live molluscs. The parasite has been described in different ecosystems from estuaries to open sea and no clear correlations could he demonstrated between the disease development and environmental parameters like temperature or salinity. The infection can he directly transmitted by cohabitation between infected and non infected oysters. Nevertheless, the parasite life cycle, including its survival outside the host, is not completely... |
| Tipo: Text |
Palavras-chave: Impact; Salinity; Temperature; Flow cytometry; Bonamia ostreae; Parasite; Ostrea edulis; Oyster. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/acte-3372.pdf |
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| Lapegue, Sylvie; Heurtebise, Serge; Harrang, Estelle; Morga, Benjamin; Flahauw, Emilie; Sauvage, Christopher; Boudry, Pierre. |
| During the last five years, a great effort has been made to develop genomic tools in oyster species all over the world. In Europe, the Pacific cupped oyster, Crassostrea gigas, and the European flat oyster, Ostrea edulis received a special attention as they are the key species for local aquaculture. In particular, the Pacific oyster is a marine bivalve of major economical and ecological importance worldwide. Better knowledge of its physiology and its genetics contributes to optimize its aquaculture production using selective breeding or to understand its invasive behavior in some coastal areas. Current international developments of genomic resources include EST databases, BAC libraries, genome mapping and sequencing. The Genoscope (Evry, France) and the... |
| Tipo: Text |
Palavras-chave: Oysters; Crassostrea gigas; Ostrea edulis; Resistance pathogens; QTLs; Single Nucleotide Polymorphism. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00015/12584/9454.pdf |
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| Vincent Hubert, Francoise; Wacrenier, Candice; Morga, Benjamin; Lozach, Solen; Quenot, Emmanuelle; Mege, Mickael; Lecadet, Cyrielle; Gourmelon, Michele; Hervio-heath, Dominique; Le Guyader, Soizick. |
| The detection of viruses and bacteria which can pose a threat either to shellfish health or shellfish consumers remains difficult. The current detection methods rely on point sampling of water, a method that gives a snapshot of the microorganisms present at the time of sampling. In order to obtain better representativeness of the presence of these microorganisms over time, we have developed passive sampling using the adsorption capacities of polymer membranes. Our objectives here were to assess the feasibility of this methodology for field detection. Different types of membrane were deployed in coastal waters over 2 years and the microorganisms tested using qPCR were: human norovirus (NoV) genogroups (G)I and II, sapovirus, Vibrio spp. and the species... |
| Tipo: Text |
Palavras-chave: Norovirus; Ostreid herpes virus 1 μ Var; Vibrio spp; Microbial source tracking; Sea; Passive sampler; Oyster (Crassostrea gigas). |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00682/79375/81893.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... |
| Tipo: Text |
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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| 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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| Burge, Colleen A.; Reecez, Kimberly S.; Dhar, Arun K.; Kirkland, Peter; Morga, Benjamin; Degremont, Lionel; Faury, Nicole; Wippel, Bryanda J. T.; Macintyre, Alanna; Friedman, Carolyn S.. |
| Economically devastating mortality events of farmed and wild shellfish due to infectious disease have been reported globally. Currently, one of the most significant disease threats to Pacific oyster Crassostrea gigas culture is the ostreid herpesvirus 1 (OsHV-1), in particular the emerging OsHV-1 microvariant genotypes. OsHV-1 microvariants (OsHV-1 mu vars) are spreading globally, and concern is high among growers in areas unaffected by OsHV-1. No study to date has compared the relative virulence among variants. We provide the first challenge study comparing survival of naive juvenile Pacific oysters exposed to OsHV-1 mu vars from Australia (AUS mu var) and France (FRA mu var). Oysters challenged with OsHV-1 mu vars had low survival (2.5%a exposed to AUS... |
| Tipo: Text |
Palavras-chave: Ostreid herpesvirus 1; Microvariant; OsHV-1 mu vars; POMS; Pacific oyster; Crassostrea gigas; Viral disease; QPCR; Alkalinity; Emerging infectious diseases. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00631/74277/73889.pdf |
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| Hubert, Francoise; Morga, Benjamin; Renault, Tristan; Le Guyader, Soizick. |
| Aims This study was performed to develop passive sampling methodology for the detection of two viruses in seawater in the area of shellfish production, The Norovirus (NoV), a human pathogen implicated in gastroenteritis outbreaks linked to oyster consumption and the ostreid herpesvirus type 1 (OsHV-1) a virus associated with mass mortalities of Pacific oysters. Methods and Results Commercially membranes were tested for their capacity to adsorb virus: Zetapor, gauze, nylon, low density polyethylene (LDPE) and Polyvinylidene difluoride (PVDF). Laboratory exposures of membranes to contaminated water samples (stool, sewage, seawater) were performed. Our data shown that the amount of NoV GII genome per membrane measured with qRT-PCR increased with the time of... |
| Tipo: Text |
Palavras-chave: Norovirus; OsHV-1; Pacific oysters; Passive samplers; Seawater; Sewage. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00365/47646/47670.pdf |
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| Morga, Benjamin; Renault, Tristan; Faury, Nicole; Chollet, Bruno; Arzul, Isabelle. |
| Bonamia ostreae is a protozoan, affiliated to the order Haplosporidia and to the phylum Cercozoa. This parasite is intracellular and infects haemocytes, cells notably involved in oyster defence mechanisms. Bonamiosis due to the parasite B. ostreae is a disease affecting the flat oyster, Ostrea edulis. The strategies used by protozoan parasites to circumvent host defence mechanisms remain largely unknown in marine bivalve molluscs. In the present work, in vitro experiments were carried out in order to study the interactions between haemocytes from O. edulis and purified parasite. B. ostreae. We monitored cellular and molecular responses of oyster haemocytes by light microscopy, flow cytometry and real-time PCR 1, 2, 4 and 8 h p.i. Light microscopy was used... |
| Tipo: Text |
Palavras-chave: Bonamia ostreae; Protozoan; Ostrea edulis; Haemocytes; Real-time PCR; Flow cytometry; Super oxide dismutase. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00037/14874/18001.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... |
| Tipo: Text |
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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| Arzul, Isabelle; Gagnaire, Beatrice; Bond, Celine; Chollet, Bruno; Morga, Benjamin; Ferrand, Sylvie; Robert, Maeva; Renault, Tristan. |
| Bonamiosis due to the intrahaemocytic protistan parasite Bonamia ostreae is a European endemic disease affecting the flat oyster Ostrea edulis. The parasite has been described in various ecosystems from estuaries to open sea, but no clear correlation has yet been demonstrated between disease development and environmental parameters. In this study, the effect of temperature and salinity on the survival of purified parasites maintained in vitro in seawater was investigated by flow cytometry. Purified parasites were incubated in various seawater media (artificial seawater, natural seawater, seabed borewater) at various temperatures (4, 15 and 25°C) and subjected to a range of salinities from 5 to 45 g l1. Parasites were collected after 12, 24 and 48 h of... |
| Tipo: Text |
Palavras-chave: Salinity tolerance; Temperature tolerance; Cell viability; In vitro assays; Flow cytometry; Bonamia ostreae. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6443.pdf |
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| Registros recuperados: 57 | |
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