6 results on '"Robert L. Atmar"'
Search Results
2. Human Norovirus Replication in Human Intestinal Enteroids as Model to Evaluate Virus Inactivation
- Author
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Veronica Costantini, Esther K. Morantz, Hannah Browne, Khalil Ettayebi, Xi-Lei Zeng, Robert L. Atmar, Mary K. Estes, and Jan Vinjé
- Subjects
norovirus ,human intestinal enteroids ,inactivation ,viruses ,replication ,virus inactivation ,Medicine ,Infectious and parasitic diseases ,RC109-216 - Abstract
Human noroviruses are a leading cause of epidemic and endemic acute gastroenteritis worldwide and a leading cause of foodborne illness in the United States. Recently, human intestinal enteroids (HIEs) derived from human small intestinal tissue have been shown to support human norovirus replication. We implemented the HIE system in our laboratory and tested the effect of chlorine and alcohols on human norovirus infectivity. Successful replication was observed for 6 norovirus GII genotypes and was dependent on viral load and genotype of the inoculum. GII.4 viruses had higher replication levels than other genotypes. Regardless of concentration or exposure time, alcohols slightly reduced, but did not completely inactivate, human norovirus. In contrast, complete inactivation of the 3 GII.4 viruses occurred at concentrations as low as 50 ppm of chlorine. Taken together, our data confirm the successful replication of human noroviruses in HIEs and their utility as tools to study norovirus inactivation strategies.
- Published
- 2018
- Full Text
- View/download PDF
3. Lack of Norovirus Replication and Histo-Blood Group Antigen Expression in 3-Dimensional Intestinal Epithelial Cells
- Author
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Melissa M. Herbst-Kralovetz, Andrea L. Radtke, Margarita K. Lay, Brooke E. Hjelm, Alice N. Bolick, Shameema S. Sarker, Robert L. Atmar, David H. Kingsley, Charles J. Arntzen, Mary K. Estes, and Cheryl A. Nickerson
- Subjects
norovirus replication ,3-D intestinal epithelial cell culture ,INT-407 ,blood group H type antigens ,Lewis blood-group system ,human intestinal epithelial cells ,Medicine ,Infectious and parasitic diseases ,RC109-216 - Abstract
Noroviruses (NoVs) are a leading cause of gastroenteritis worldwide. An in vitro model for NoV replication remains elusive, making study of the virus difficult. A previous study, which used a 3-dimensional (3-D) intestinal model derived from INT-407 cells reported NoV replication and extensive cytopathic effects (CPE). Using the same 3-D model, but with highly purified Norwalk virus (NV), we attempted to replicate this study. Our results showed no evidence of NV replication by real-time PCR of viral RNA or by immunocytochemical detection of viral structural and nonstructural proteins. Immunocytochemical analysis of the 3-D cultures also showed no detectable presence of histo-blood group antigens that participate in NV binding and host tropism. To determine the potential cause of CPE observed in the previous study, we exposed 3-D cultures to lipopolysaccharide concentrations consistent with contaminated stool samples and observed morphologic features similar to CPE. We conclude that the 3-D INT-407 model does not support NV replication.
- Published
- 2013
- Full Text
- View/download PDF
4. Norwalk Virus Shedding after Experimental Human Infection
- Author
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Robert L. Atmar, Antone R. Opekun, Mark A. Gilger, Mary K. Estes, Sue E. Crawford, Frederick H. Neill, and David Y. Graham
- Subjects
norovirus ,gastroenteritis ,RT-PCR ,Norwalk virus ,adult ,human ,Medicine ,Infectious and parasitic diseases ,RC109-216 - Abstract
Noroviruses are the most common cause of viral gastroenteritis in the United States. To determine the magnitude and duration of virus shedding in feces, we evaluated persons who had been experimentally infected with Norwalk virus. Of 16 persons, clinical gastroenteritis (watery diarrhea and/or vomiting) developed in 11; symptomatic illness lasted 1–2 days. Virus shedding was first detected by reverse transcription–PCR (RT-PCR) 18 hours after participant inoculation and lasted a median of 28 days after inoculation (range 13–56 days). The median peak amount of virus shedding was 95 × 109 (range 0.5–1,640 ×109) genomic copies/g feces as measured by quantitative RT-PCR. Virus shedding was first detected by antigen ELISA ≈33 hours (median 42 hours) after inoculation and lasted 10 days (median 7 days) after inoculation. Understanding of the relevance of prolonged fecal norovirus excretion must await the development of sensitive methods to measure virus infectivity.
- Published
- 2008
- Full Text
- View/download PDF
5. Norwalk Virus–specific Binding to Oyster Digestive Tissues
- Author
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Françoise S. Le Guyader, Fabienne Loisy, Robert L. Atmar, Anne M. Hutson, Mary K. Estes, Nathalie Ruvoën-Clouet, Monique Pommepuy, and Jacques Le Pendu
- Subjects
Norovirus ,calicivirus ,shellfish ,carbohydrate ,pathogen selection ,virus-like particles ,Medicine ,Infectious and parasitic diseases ,RC109-216 - Abstract
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 α linkage (same binding site used for recognition of human histo-blood group antigens). These data show that the oyster can selectively concentrate a human pathogen and that conventional depuration will not eliminate noroviruses from oyster tissue.
- Published
- 2006
- Full Text
- View/download PDF
6. Lack of Norovirus Replication and Histo-Blood Group Antigen Expression in 3-Dimensional Intestinal Epithelial Cells
- Author
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Mary K. Estes, Melissa M. Herbst-Kralovetz, Margarita K. Lay, David H. Kingsley, Robert L. Atmar, Brooke E. Hjelm, Cheryl A. Nickerson, Shameema Sarker, Andrea L. Radtke, Alice N. Bolick, and Charles J. Arntzen
- Subjects
Microbiology (medical) ,Lipopolysaccharides ,Epidemiology ,viruses ,Cell Culture Techniques ,Host tropism ,lcsh:Medicine ,human intestinal epithelial cells ,Viral Nonstructural Proteins ,medicine.disease_cause ,Real-Time Polymerase Chain Reaction ,Virus Replication ,Virus ,Microbiology ,lcsh:Infectious and parasitic diseases ,Cell Line ,Intestinal mucosa ,INT-407 ,medicine ,3-D intestinal epithelial cell culture ,Humans ,lcsh:RC109-216 ,norovirus replication ,Intestinal Mucosa ,rotating wall vessel bioreactor ,Cell Aggregation ,Viral Structural Proteins ,biology ,blood group H type antigens ,Research ,lcsh:R ,Norovirus ,Epithelial Cells ,biology.organism_classification ,Virology ,Cell aggregation ,Gastroenteritis ,Norwalk virus ,Viral Tropism ,Infectious Diseases ,Viral replication ,Tissue tropism ,Blood Group Antigens ,RNA, Viral ,Lewis blood-group system - Abstract
TOC summary: The 3-dimensional intestinal model is not sufficient as a virus replication system for developing vaccines or drugs to control human norovirus infections., Noroviruses (NoVs) are a leading cause of gastroenteritis worldwide. An in vitro model for NoV replication remains elusive, making study of the virus difficult. A previous study, which used a 3-dimensional (3-D) intestinal model derived from INT-407 cells reported NoV replication and extensive cytopathic effects (CPE). Using the same 3-D model, but with highly purified Norwalk virus (NV), we attempted to replicate this study. Our results showed no evidence of NV replication by real-time PCR of viral RNA or by immunocytochemical detection of viral structural and nonstructural proteins. Immunocytochemical analysis of the 3-D cultures also showed no detectable presence of histo-blood group antigens that participate in NV binding and host tropism. To determine the potential cause of CPE observed in the previous study, we exposed 3-D cultures to lipopolysaccharide concentrations consistent with contaminated stool samples and observed morphologic features similar to CPE. We conclude that the 3-D INT-407 model does not support NV replication.
- Published
- 2013
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