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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... |
| Tipo: Text |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6137.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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| Loisy, Fabienne; Atmar, R; Le Saux, Jean-claude; Cohen, J; Caprais, Marie-paule; Pommepuy, Monique; Le Guyader, Soizick. |
| Rotavirus virus-like particles (VLPs) and MS2 bacteriophages were bioaccumulated in bivalve mollusks to evaluate viral persistence in shellfish during depuration and relaying under natural conditions. Using this nonpathogenic surrogate virus, we were able to demonstrate that about 1 log(10) of VLPs was depurated after 1 week in warm seawater (22 degrees C). Phage MS2 was depurated more rapidly (about 2 log(10) in 1 week) than were VLPs, as determined using a single-compartment model and linear regression analysis. After being relayed in the estuary under the influence of the tides, VLPs were detected in oysters for up to 82 days following seeding with high levels of VLPs (concentration range between 10(10) and 10(9) particles per g of pancreatic tissue)... |
| Tipo: Text |
Palavras-chave: Seawater; Viral diseases; Bioaccumulation; Depuration; Contamination; Model; Pancreas; Regression analysis; Shellfish; Phages; Virus. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-1233.pdf |
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| Le Guyader, Soizick; Loisy, Fabienne; Atmar, R; Hutson, A; Estes, M; Ruvoen-clouet, N; Pommepuy, Monique; Le Pendu, J. |
| The primary pathogens related to shellfishborne gastroenteritis outbreaks are noroviruses. These viruses show persistence in oysters, which suggests an active mechanism of virus concentration. We investigated whether Norwalk virus or viruslike particles bind specifically to oyster tissues after bioaccumulation or addition to tissue sections. Since noroviruses attach to carbohydrates of the histo-blood group family, tests using immunohistochemical analysis were performed to evaluate specific binding of virus or viruslike particles to oyster tissues through these ligands. Viral particles bind specifically to digestive ducts (midgut, main and secondary ducts, and tubules) by carbohydrate structures with a terminal N-acetylgalactosamine residue in an alpha... |
| Tipo: Text |
Palavras-chave: Bioaccumulation; Shellfish; Escherichia coli; Pathogen; Oyster digestive tissue; Noroviruses. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1542.pdf |
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| Costantini, V; Loisy, Fabienne; Joens, L; Le Guyader, Soizick; Saif, L. |
| Food-borne diseases are a major cause of morbidity and hospitalization worldwide. Enteric caliciviruses are capable of persisting in the environment and in the tissues of shellfish. Human noroviruses (HuNoVs) have been implicated in outbreaks linked to shellfish consumption. The genetic and antigenic relatedness between human and animal enteric calliciviruses suggests that interspecies transmission may occur. To determine the occurrence of human and animal enteric calliciviruses in United States market oysters, we surveyed regional markets. Oysters were collected from 45 bays along the United States coast during the summer and winter of 2002 and 2003. Samples were analyzed by reverse transcription-PCR, and results were confirmed by hybridization and... |
| Tipo: Text |
Palavras-chave: Monitoring; Microbiology; Sampling; Oyster; Shellfish tissue; Human norovirus; Calicivirus. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1235.pdf |
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