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| Le Guyader, Soizick; Le Saux, Jean-claude; Ambert-balay, Katia; Krol, Joanna; Serais, Ophelie; Parnaudeau, Sylvain; Giraudon, Helene; Delmas, Gilles; Pommepuy, Monique; Pothier, Pierre; Atmar, Robert L.. |
| Following a flooding event close to a shellfish production lagoon, 205 cases of gastroenteritis were linked to oyster consumption. Twelve stool samples from different individuals were collected. Analysis showed that eight samples were positive for multiple enteric viruses, and one stool sample had seven different enteric viruses. Analysis of shellfish implicated in the outbreak allowed detection of the same diversity of enteric viruses, with some viral genomic sequences being identical to those obtained from stool sample analysis. Shellfish were contaminated by as many as five different enteric viruses. For the first time in Europe, Aichi virus was identified in oyster samples. Shellfish samples collected over 3 weeks following the outbreak showed a... |
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| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6099.pdf |
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| Le Guyader, Soizick; Krol, Joanna; Ambert-balay, Katia; Ruvoen-clouet, Nathalie; Desaubliaux, Benedicte; Parnaudeau, Sylvain; Le Saux, Jean-claude; Ponge, Agnes; Pothier, Pierre; Atmar, Robert L.; Le Pendu, Jacques. |
| Noroviruses have been recognized to be the predominant agents of nonbacterial gastroenteritis outbreaks in humans, and their transmission via contaminated shellfish consumption has been demonstrated. Norovirus laboratory experiments, volunteer challenge studies, and community gastroenteritis outbreak investigations have identified human genetic susceptibility factors related to histo-blood group antigen expression. Following a banquet in Brittany, France, in February 2008, gastroenteritis cases were linked to oyster consumption. This study identified an association of the norovirus illnesses with histo-blood group expression, and oyster contamination with norovirus was confirmed by qualitative and quantitative analyses. The secretor phenotype was... |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11309/8050.pdf |
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| Le Guyader, Soizick; Parnaudeau, Sylvain; Schaeffer, Julien; Bosch, Albert; Loisy, Fabienne; Pommepuy, Monique; Atmar, Robert L.. |
| Noroviruses (NoVs) are the most common viral agents of acute gastroenteritis in humans, and high concentrations of NoVs are discharged into the environment. As these viruses are very resistant to inactivation, the sanitary consequences are contamination of food, including molluscan shellfish. There are four major problems with NoV detection in shellfish samples: low levels of virus contamination, the difficulty of efficient virus extraction, the presence of interfering substances that inhibit molecular detection, and NoV genetic variability. The aims of this study were to adapt a kit for use with a method previously shown to be efficient for detection of NoV in shellfish and to use a one step real-time reverse transcription-PCR method with addition of an... |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6137.pdf |
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| Maalouf, Haifa; Zakhour, Maha; Le Pendu, Jacques; Le Saux, Jean-claude; Atmar, Robert L.; Le Guyader, Francoise S.. |
| Bivalve molluscan shellfish, such as oysters, filter large volumes of water as part of their feeding activities and are able to accumulate and concentrate different types of pathogens, particularly noroviruses, from fecal human pollution. Based on our previous observation of a specific binding of the Norwalk strain (prototype norovirus genogroup I) to the oyster digestive tract through an A-like carbohydrate structure indistinguishable from human blood group A antigen and on the large diversity between strains in terms of carbohydrate-binding specificities, we evaluated the different ligands implicated in attachment to oysters tissues of strains representative of two main genogroups of human norovirus. The GI.1 and GII.4 strains differed in that the latter... |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00011/12215/9045.pdf |
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| Miura, Takayuki; Parnaudeau, Sylvain; Grodzki, Marco; Okabe, Satoshi; Atmar, Robert L.; Le Guyader, Soizick. |
| Norovirus is the most common agent implicated in food-borne outbreaks and is frequently detected in environmental samples. These viruses are highly diverse, and three genogroups (genogroup I [GI], GII, and GIV) infect humans. Being noncultivable viruses, real-time reverse transcription-PCR (RT-PCR) is the only sensitive method available for their detection in food or environmental samples. Selection of consensus sequences for the design of sensitive assays has been challenging due to sequence diversity and has led to the development of specific real-time RT-PCR assays for each genogroup. Thus, sample screening can require several replicates for amplification of each genogroup (without considering positive and negative controls or standard curves). This... |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00162/27313/25544.pdf |
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| Loisy, Fabienne; Atmar, Robert L.; Cohen, Jean; Bosch, Albert; Le Guyader, Soizick. |
| The potential of rotavirus 2/6-virus-like-particles (VLP2/6) for use as tracers in the marine environment was investigated. The stability of bovine rotavirus (strain RF) and VLP2/6 in natural seawater at 25degreesC for six days was studied. ELISA and western blot methods were used to quantify the particles. The rates of decline of rotavirus particles and VLP2/6 were similar (approximately 0.5 log 10 per day). Western blot analysis showed that the integrity of capsid proteins VP2 and VP6 was conserved during the incubation time. These results demonstrate that VLP2/6 particles have the same stability in seawater as rotavirus particles. Thus, VLP2/6 can be used as a tracer, which should be of particular value for studying the fate of rotavirus particles in... |
| Tipo: Text |
Palavras-chave: Stability; Tracer; Seawater; Virus like particles; Rotavirus. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/2004/publication-330.pdf |
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| Maalouf, Haifa; Schaeffer, Julien; Parnaudeau, Sylvain; Le Pendu, Jacques; Atmar, Robert L.; Crawford, Sue E.; Le Guyader, Soizick. |
| Noroviruses (NoVs) are the main agents of gastroenteritis in humans and the primary pathogens of shellfish-related outbreaks. Some NoV strains bind to shellfish tissues by using carbohydrate structures similar to their human ligands, leading to the hypothesis that such ligands may influence bioaccumulation. This study compares the bioaccumulation efficiencies and tissue distributions in oysters (Crassostrea gigas) of three strains from the two principal human norovirus genogroups. Clear differences between strains were observed. The GI.1 strain was the most efficiently concentrated strain. Bioaccumulation specifically occurred in digestive tissues in a dose-dependent manner, and its efficiency paralleled ligand expression, which was highest during the cold... |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00036/14753/12087.pdf |
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| Le Guyader, Soizick; Atmar, Robert L.; Le Pendu, Jacques. |
| Shellfish are known as vectors for human pathogens and despite regulation based on enteric bacteria they are still implicated in viral outbreaks. Among shellfish, oysters are the most common vector of contamination, and the pathogens most frequently involved in these outbreaks are noroviruses, responsible for acute gastroenteritis in humans. Analysis of shellfish-related outbreak data worldwide show an unexpected high proportion of NoV GI strains. Recent studies performed in vitro, in vivo and in the environment indicate that oysters are not just passive filters, but can selectively accumulate norovirus strains based on viral carbohydrate ligands shared with humans. These observations contribute to explain the GI bias observed in shellfish-related... |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00114/22516/20238.pdf |
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