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Sample records for human noroviruses response

  1. Cell Culture Assay for Human Noroviruses [response

    SciTech Connect

    Straub, Tim M.; Honer Zu Bentrup, Kerstin; Orosz Coghlan, Patricia; Dohnalkova, Alice; Mayer, Brooke K.; Bartholomew, Rachel A.; Valdez, Catherine O.; Bruckner-Lea, Cindy J.; Gerba, Charles P.; Abbaszadegan, Morteza A.; Nickerson, Cheryl A.

    2007-07-01

    We appreciate the comments provided by Leung et al., in response to our recently published article “In Vitro Cell Culture Infectivity Assay for Human Noroviruses” by Straub et al. (1). The specific aim of our project was to develop an in vitro cell culture infectivity assay for human noroviruses (hNoV) to enhance risk assessments when they are detected in water supplies. Reverse transcription (RT) qualitative or quantitative PCR are the primary assays for waterborne NoV monitoring. However, these assays cannot distinguish between infectious vs. non-infectious virions. When hNoV is detected in water supplies, information provided by our infectivity assay will significantly improve risk assessment models and protect human health, regardless of whether we are propagating NoV. Indeed, in vitro cell culture infectivity assays for the waterborne pathogen Cryptosporidium parvum that supplement approved fluorescent microscopy assays, do not result in amplification of the environmentally resistant hard-walled oocysts (2). However, identification of life cycle stages in cell culture provides evidence of infectious oocysts in a water supply. Nonetheless, Leung et al.’s assertion regarding the suitability of our method for the in vitro propagation of high titers of NoV is valid for the medical research community. In this case, well-characterized challenge pools of virus would be useful for developing and testing diagnostics, therapeutics, and vaccines. As further validation of our published findings, we have now optimized RT quantitative PCR to assess the level of viral production in cell culture, where we are indeed finding significant increases in viral titer. The magnitude and time course of these increases is dependent on both virus strain and multiplicity of infection. We are currently preparing a manuscript that will discuss these findings in greater detail, and the implications this may have for creating viral challenge pools

  2. Human Norovirus and Its Surrogates Induce Plant Immune Response in Arabidopsis thaliana and Lactuca sativa.

    PubMed

    Markland, Sarah M; Bais, Harsh; Kniel, Kalmia E

    2017-08-01

    Human norovirus is the leading cause of foodborne illness worldwide with the majority of outbreaks linked to fresh produce and leafy greens. It is essential that we thoroughly understand the type of relationship and interactions that take place between plants and human norovirus to better utilize control strategies to reduce transmission of norovirus in the field onto plants harvested for human consumption. In this study the expression of gene markers for the salicylic acid (SA) and jasmonic acid (JA) plant defense pathways was measured and compared in romaine lettuce (Lactuca sativa) and Arabidopsis thaliana Col-0 plants that were inoculated with Murine Norovirus-1, Tulane Virus, human norovirus GII.4, or Hank's Balanced Salt Solution (control). Genes involving both the SA and JA pathways were expressed in both romaine lettuce and A. thaliana for all three viruses, as well as controls. Studies, including gene expression of SA- and JA-deficient A. thaliana mutant lines, suggest that the JA pathway is more likely involved in the plant immune response to human norovirus. This research provides the first pieces of information regarding how foodborne viruses interact with plants in the preharvest environment.

  3. Newcastle Disease Virus Vector Producing Human Norovirus-Like Particles Induces Serum, Cellular, and Mucosal Immune Responses in Mice

    PubMed Central

    Kim, Shin-Hee; Chen, Shun; Jiang, Xi; Green, Kim Y.

    2014-01-01

    ABSTRACT Human norovirus infection is the most common cause of viral gastroenteritis worldwide. Development of an effective vaccine is required for reducing norovirus outbreaks. The inability to grow human norovirus in cell culture has hindered the development of live-attenuated vaccines. To overcome this obstacle, we generated a recombinant Newcastle disease virus (rNDV)-vectored experimental norovirus vaccine by expressing the capsid protein (VP1) of norovirus strain VA387. We compared two different NDV vectors, a conventional rNDV vector and a modified rNDV vector, for their efficiencies in expressing VP1 protein. Our results showed that the modified vector replicated to higher titers and expressed higher levels of VP1 protein in DF1 cells and in allantoic fluid of embryonated chicken eggs than did the conventional vector. We further demonstrated that the VP1 protein produced by rNDVs was able to self-assemble into virus-like particles (VLPs) that are morphologically similar to baculovirus-expressed VLPs. Evaluation of their immunogenicity in mice showed that the modified rNDV vector induced a higher level of IgG response than those induced by the conventional vector and by the baculovirus-expressed VLPs. The rNDV vectors predominantly induced IgG2a subclass antibody for the Th1 response, and specifically, high levels of gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukin-2 (IL-2) were detected in splenocytes. In addition, the modified rNDV vector induced a higher level of fecal IgA response in mice than did baculovirus-expressed VLPs. Our findings suggest that the rNDV vector is an efficient system to produce cost-effective VLPs in embryonated chicken eggs and has the potential to be used as a live-attenuated vaccine in humans. IMPORTANCE Noroviruses are the major cause of viral gastroenteritis worldwide. Currently, effective vaccines against norovirus infection are not available. In this study, we have evaluated Newcastle disease

  4. Replication of Human Norovirus RNA in Mammalian Cells Reveals Lack of Interferon Response

    PubMed Central

    Qu, Lin; Murakami, Kosuke; Broughman, James R.; Lay, Margarita K.; Guix, Susana; Tenge, Victoria R.; Atmar, Robert L.

    2016-01-01

    ABSTRACT Human noroviruses (HuNoVs), named after the prototype strain Norwalk virus (NV), are a leading cause of acute gastroenteritis outbreaks worldwide. Studies on the related murine norovirus (MNV) have demonstrated the importance of an interferon (IFN) response in host control of virus replication, but this remains unclear for HuNoVs. Despite the lack of an efficient cell culture infection system, transfection of stool-isolated NV RNA into mammalian cells leads to viral RNA replication and virus production. Using this system, we show here that NV RNA replication is sensitive to type I (α/β) and III (interleukin-29 [IL-29]) IFN treatment. However, in cells capable of a strong IFN response to Sendai virus (SeV) and poly(I·C), NV RNA replicates efficiently and generates double-stranded RNA without inducing a detectable IFN response. Replication of HuNoV genogroup GII.3 strain U201 RNA, generated from a reverse genetics system, also does not induce an IFN response. Consistent with a lack of IFN induction, NV RNA replication is enhanced neither by neutralization of type I/III IFNs through neutralizing antibodies or the soluble IFN decoy receptor B18R nor by short hairpin RNA (shRNA) knockdown of mitochondrial antiviral signaling protein (MAVS) or interferon regulatory factor 3 (IRF3) in the IFN induction pathways. In contrast to other positive-strand RNA viruses that block IFN induction by targeting MAVS for degradation, MAVS is not degraded in NV RNA-replicating cells, and an SeV-induced IFN response is not blocked. Together, these results indicate that HuNoV RNA replication in mammalian cells does not induce an IFN response, suggesting that the epithelial IFN response may play a limited role in host restriction of HuNoV replication. IMPORTANCE Human noroviruses (HuNoVs) are a leading cause of epidemic gastroenteritis worldwide. Due to lack of an efficient cell culture system and robust small-animal model, little is known about the innate host defense to these

  5. Strain-Specific Virolysis Patterns of Human Noroviruses in Response to Alcohols

    PubMed Central

    Park, Geun Woo; Collins, Nikail; Barclay, Leslie; Hu, Liya; Prasad, B. V. Venkataram; Lopman, Benjamin A.; Vinjé, Jan

    2016-01-01

    Alcohol-based hand sanitizers are widely used to disinfect hands to prevent the spread of pathogens including noroviruses. Alcohols inactivate norovirus by destruction of the viral capsid, resulting in the leakage of viral RNA (virolysis). Since conflicting results have been reported on the susceptibility of human noroviruses against alcohols, we exposed a panel of 30 human norovirus strains (14 GI and 16 GII strains) to different concentrations (50%, 70%, 90%) of ethanol and isopropanol and tested the viral RNA titer by RT-qPCR. Viral RNA titers of 10 (71.4%), 14 (100%), 3 (21.4%) and 7 (50%) of the 14 GI strains were reduced by > 1 log10 RNA copies/ml after exposure to 70% and 90% ethanol, and 70% and 90% isopropanol, respectively. RNA titers of 6 of the 7 non-GII 4 strains remained unaffected after alcohol exposure. Compared to GII strains, GI strains were more susceptible to ethanol than to isopropanol. At 90%, both alcohols reduced RNA titers of 8 of the 9 GII.4 strains by ≥ 1 log10 RNA copies/ml. After exposure to 70% ethanol, RNA titers of GII.4 Den Haag and Sydney strains decreased by ≥ 1.9 log10, whereas RNA reductions for GII.4 New Orleans strains were < 0.5 log10. To explain these differences, we sequenced the complete capsid gene of the 9 GII.4 strains and identified 17 amino acid substitutions in the P2 region among the 3 GII.4 variant viruses. When comparing with an additional set of 200 GII.4 VP1 sequences, only S310 and P396 were present in all GII.4 New Orleans viruses but not in the ethanol-sensitive GII.4 Sydney and GII.4 Den Haag viruses Our data demonstrate that alcohol susceptibility patterns between different norovirus genotypes vary widely and that virolysis data for a single strain or genotype are not representative for all noroviruses. PMID:27337036

  6. Norovirus-Specific Memory T Cell Responses in Adult Human Donors

    PubMed Central

    Malm, Maria; Tamminen, Kirsi; Vesikari, Timo; Blazevic, Vesna

    2016-01-01

    Norovirus (NoV) is a leading cause of acute gastroenteritis in people of all ages worldwide. NoV-specific serum antibodies which block the binding of NoV virus-like particles (VLPs) to the cell receptors have been thoroughly investigated. In contrast, only a few publications are available on the NoV capsid VP1 protein-specific T cell responses in humans naturally infected with the virus. Freshly isolated peripheral blood mononuclear cells of eight healthy adult human donors previously exposed to NoV were stimulated with purified VLPs derived from NoV GII.4-1999, GII.4-2012 (Sydney), and GI.3, and IFN-γ production was measured by an ELISPOT assay. In addition, 76 overlapping synthetic peptides spanning the entire 539-amino acid sequence of GII.4 VP1 were pooled into two-dimensional matrices and used to identify putative T cell epitopes. Seven of the eight subjects produced IFN-γ in response to the peptides and five subjects produced IFN-γ in response to the VLPs of the same origin. In general, stronger T cell responses were induced with the peptides in each donor compared to the VLPs. A CD8+ T cell epitope in the shell domain of the VP1 (134SPSQVTMFPHIIVDVRQL151) was identified in two subjects, both having human leukocyte antigen (HLA)-A∗02:01 allele. To our knowledge, this is the first report using synthetic peptides to study NoV-specific T cell responses in human subjects and identify T cell epitopes. PMID:27752254

  7. Fractional poisson--a simple dose-response model for human norovirus.

    PubMed

    Messner, Michael J; Berger, Philip; Nappier, Sharon P

    2014-10-01

    This study utilizes old and new Norovirus (NoV) human challenge data to model the dose-response relationship for human NoV infection. The combined data set is used to update estimates from a previously published beta-Poisson dose-response model that includes parameters for virus aggregation and for a beta-distribution that describes variable susceptibility among hosts. The quality of the beta-Poisson model is examined and a simpler model is proposed. The new model (fractional Poisson) characterizes hosts as either perfectly susceptible or perfectly immune, requiring a single parameter (the fraction of perfectly susceptible hosts) in place of the two-parameter beta-distribution. A second parameter is included to account for virus aggregation in the same fashion as it is added to the beta-Poisson model. Infection probability is simply the product of the probability of nonzero exposure (at least one virus or aggregate is ingested) and the fraction of susceptible hosts. The model is computationally simple and appears to be well suited to the data from the NoV human challenge studies. The model's deviance is similar to that of the beta-Poisson, but with one parameter, rather than two. As a result, the Akaike information criterion favors the fractional Poisson over the beta-Poisson model. At low, environmentally relevant exposure levels (<100), estimation error is small for the fractional Poisson model; however, caution is advised because no subjects were challenged at such a low dose. New low-dose data would be of great value to further clarify the NoV dose-response relationship and to support improved risk assessment for environmentally relevant exposures.

  8. Norovirus

    MedlinePlus

    ... of scientists at Baylor College of Medicine in Texas, who recently developed a way to grow human ... Frequently Asked Questions Norovirus Reporting in Calicinet CaliciNet Data Participating Labs References and Resources NoroSTAT NoroSTAT Data ...

  9. Environmental indicators for human norovirus outbreaks.

    PubMed

    Shamkhali Chenar, Shima; Deng, Zhiqiang

    2017-02-01

    Norovirus is the most common cause of outbreaks of non-bacterial gastroenteritis in human. While the winter seasonality of norovirus outbreaks has been widely reported, the association between norovirus outbreak epidemics and environmental factors remains not fully understood. This literature review is intended to improve understanding of environmental factors governing norovirus outbreaks and how the factors affect norovirus transmission. To that end, a large number of studies (67) from countries around the world were critically reviewed and discussed. Results of the literature review show that temperature, humidity, and rainfall are the most important environmental variables governing the norovirus epidemic cycle. It was found that low temperature between -6.6 and 20 °C, relative humidity between 10 and 66 %, and rainfall from 1 day to 3 months before an outbreak are effective ranges of the environmental factors, which favor the prevalence of norovirus. Some other environmental factors might have an association with the cycle of norovirus epidemics. However, further investigations are needed to understand effects of the other factors on norovirus incidence. The findings of this literature review improve our understanding of the relationship between norovirus outbreaks and environmental factors and provide the direction for future research on norovirus outbreaks.

  10. Norovirus

    PubMed Central

    Robilotti, Elizabeth; Deresinski, Stan

    2015-01-01

    SUMMARY Norovirus, an RNA virus of the family Caliciviridae, is a human enteric pathogen that causes substantial morbidity across both health care and community settings. Several factors enhance the transmissibility of norovirus, including the small inoculum required to produce infection (<100 viral particles), prolonged viral shedding, and its ability to survive in the environment. In this review, we describe the basic virology and immunology of noroviruses, the clinical disease resulting from infection and its diagnosis and management, as well as host and pathogen factors that complicate vaccine development. Additionally, we discuss overall epidemiology, infection control strategies, and global reporting efforts aimed at controlling this worldwide cause of acute gastroenteritis. Prompt implementation of infection control measures remains the mainstay of norovirus outbreak management. PMID:25567225

  11. Heat-Denatured Lysozyme Inactivates Murine Norovirus as a Surrogate Human Norovirus.

    PubMed

    Takahashi, Hajime; Nakazawa, Moemi; Ohshima, Chihiro; Sato, Miki; Tsuchiya, Tomoki; Takeuchi, Akira; Kunou, Masaaki; Kuda, Takashi; Kimura, Bon

    2015-07-02

    Human norovirus infects humans through the consumption of contaminated food, contact with the excrement or vomit of an infected person, and through airborne droplets that scatter the virus through the air. Being highly infectious and highly viable in the environment, inactivation of the norovirus requires a highly effective inactivating agent. In this study, we have discovered the thermal denaturing capacity of a lysozyme with known antimicrobial activity against gram-positive bacteria, as well as its inactivating effect on murine norovirus. This study is the first report on the norovirus-inactivating effects of a thermally denatured lysozyme. We observed that lysozymes heat-treated for 40 min at 100 °C caused a 4.5 log reduction in infectivity of norovirus. Transmission electron microscope analysis showed that virus particles exposed to thermally denatured lysozymes were expanded, compared to the virus before exposure. The amino acid sequence of the lysozyme was divided into three sections and the peptides of each artificially synthesised, in order to determine the region responsible for the inactivating effect. These results suggest that thermal denaturation of the lysozyme changes the protein structure, activating the region responsible for imparting an inactivating effect against the virus.

  12. B-Cell Responses to Intramuscular Administration of a Bivalent Virus-like Particle Human Norovirus Vaccine.

    PubMed

    Ramani, Sasirekha; Neill, Frederick H; Ferreira, Jennifer; Treanor, John J; Frey, Sharon E; Topham, David J; Goodwin, Robert R; Borkowski, Astrid; Baehner, Frank; Mendelman, Paul M; Estes, Mary K; Atmar, Robert L

    2017-03-01

    Human noroviruses (HuNoVs) are a leading cause of acute gastroenteritis worldwide. A virus-like particle (VLP) candidate vaccine induces the production of serum histo-blood group antigen (HBGA) blocking antibodies, the first identified correlate of protection from HuNoV gastroenteritis. Recently, virus-specific IgG memory B-cells were identified as another potential correlate of protection against HuNoV gastroenteritis. We assessed B-cell responses following intramuscular administration of a bivalent (GI.1/GII.4) VLP vaccine using protocols identical to those used to evaluate cellular immunity following experimental HuNoV infection. The kinetics and magnitude of cellular immunity to G1.1 infection versus VLP vaccination were compared. Intramuscular immunization with bivalent VLP vaccine induces the production of antibody-secreting cells (ASCs) and memory B-cells. ASC responses peaked at day 7 post 1st dose of vaccine and returned to nearly baseline levels by day 28. Minimal increases in ASCs were seen after a second vaccine dose at day 28. Antigen-specific IgG memory B-cells persist at day 180 post-vaccination for both GI.1 and GII.4 VLPs. The overall trends in B-cell responses to vaccination were similar to infection, where there was a greater bias of ASC response towards IgA and memory B-cell response to IgG. The magnitude of ASC and memory B-cell responses to the GI.1 VLP component of the vaccine were also comparable to responses following GI.1 infection. The production of IgG memory B-cells and persistence at day 180 is a key finding and underscores the need for future studies to determine if IgG memory B-cells are a correlate of protection following vaccination.

  13. Low-Density microarray technologies for rapid human norovirus genotyping

    USDA-ARS?s Scientific Manuscript database

    Human noroviruses (HuNoV) are the most common cause of food borne disease and viruses are likely responsible for a large proportion of foodborne diseases of unknown etiology. Recent advancements in molecular biology, bioinformatics, epidemiology, and risk analysis have aided the study of these agent...

  14. Norovirus

    MedlinePlus

    ... Norovirus Infection, National Institutes of Health NoroCORE Food Virology About Norovirus Language: English Español (Spanish) Recommend on ... Norovirus Infection, National Institutes of Health NoroCORE Food Virology Language: English Español (Spanish) File Formats Help: How ...

  15. Inactivation of human norovirus using chemical sanitizers

    USDA-ARS?s Scientific Manuscript database

    The porcine gastric mucin binding magnetic bead (PGM-MB) assay was used to evaluate the ability of chlorine, chlorine dioxide, peroxyacetic acid, hydrogen peroxide, and trisodium phosphate to inactivate human norovirus within 10 percent stool filtrate. One min free chlorine treatments at concentrat...

  16. Inactivation of human norovirus using chemical sanitizers.

    PubMed

    Kingsley, David H; Vincent, Emily M; Meade, Gloria K; Watson, Clytrice L; Fan, Xuetong

    2014-02-03

    The porcine gastric mucin binding magnetic bead (PGM-MB) assay was used to evaluate the ability of chlorine, chlorine dioxide, peroxyacetic acid, hydrogen peroxide, and trisodium phosphate to inactivate human norovirus within 10% stool filtrate. One-minute free chlorine treatments at concentrations of 33 and 189 ppm reduced virus binding in the PGM-MB assay by 1.48 and 4.14 log₁₀, respectively, suggesting that chlorine is an efficient sanitizer for inactivation of human norovirus (HuNoV). Five minute treatments with 5% trisodium phosphate (pH~12) reduced HuNoV binding by 1.6 log₁₀, suggesting that TSP, or some other high pH buffer, could be used to treat food and food contact surfaces to reduce HuNoV. One minute treatments with 350 ppm chlorine dioxide dissolved in water did not reduce PGM-MB binding, suggesting that the sanitizer may not be suitable for HuNoV inactivation in liquid form. However a 60-min treatment with 350 ppm chlorine dioxide did reduce human norovirus by 2.8 log₁₀, indicating that chlorine dioxide had some, albeit limited, activity against HuNoV. Results also suggest that peroxyacetic acid has limited effectiveness against human norovirus, since 1-min treatments with up to 195 ppm reduced human norovirus binding by <1 log₁₀. Hydrogen peroxide (4%) treatment of up to 60 min resulted in minimal binding reduction (~0.1 log₁₀) suggesting that H₂O₂ is not a good liquid sanitizer for HuNoV. Overall this study suggests that HuNoV is remarkably resistant to several commonly used disinfectants and advocates for the use of chlorine (sodium hypochlorite) as a HuNoV disinfectant wherever possible.

  17. Use of Murine Norovirus as a Surrogate To Evaluate Resistance of Human Norovirus to Disinfectants▿

    PubMed Central

    Belliot, Gaël; Lavaux, Amandine; Souihel, Donya; Agnello, Davide; Pothier, Pierre

    2008-01-01

    Murine norovirus (MNV) was used as a surrogate to study resistance of human norovirus to disinfectants used in hospitals. MNV was sensitive to alcohol, alcohol hand rubs, bleach, and povidone iodine-based disinfectant. Real-time reverse transcription-PCR results indicated that the presence of viral RNA did not correlate with the presence of infectious virus. PMID:18378650

  18. Serum Immunoglobulin A Cross-Strain Blockade of Human Noroviruses

    PubMed Central

    Lindesmith, Lisa C.; Beltramello, Martina; Swanstrom, Jesica; Jones, Taylor A.; Corti, Davide; Lanzavecchia, Antonio; Baric, Ralph S.

    2015-01-01

    Background. Human noroviruses are the leading cause of acute viral gastroenteritis, justifying vaccine development despite a limited understanding of strain immunity. After genogroup I (GI).1 norovirus infection and immunization, blockade antibody titers to multiple virus-like particles (VLPs) increase, suggesting that GI cross-protection may occur. Methods. Immunoglobulin (Ig)A was purified from sera collected from GI.1-infected participants, and potential neutralization activity was measured using a surrogate neutralization assay based on antibody blockade of ligand binding. Human and mouse monoclonal antibodies (mAbs) were produced to multiple GI VLPs to characterize GI epitopes. Results. Immunoglobulin A purified from day 14 post-GI.1 challenge sera blocked binding of GI.1, GI.3, and GI.4 to carbohydrate ligands. In some subjects, purified IgA preferentially blocked binding of other GI VLPs compared with GI.1, supporting observations that the immune response to GI.1 infection may be influenced by pre-exposure history. For other subjects, IgA equivalently blocked multiple GI VLPs. Only strain-specific mAbs recognized blockade epitopes, whereas strain cross-reactive mAbs recognized nonblockade epitopes. Conclusions. These studies are the first to describe a functional role for serum IgA in norovirus immunity and the first to characterize human monoclonal antibodies to GI strains, expanding our understanding of norovirus immunobiology. PMID:26180833

  19. Mechanisms of GII.4 Norovirus Persistence in Human Populations

    PubMed Central

    LoBue, Anna D; Cannon, Jennifer L; Zheng, Du-Ping; Vinje, Jan; Baric, Ralph S

    2008-01-01

    cluster were expressed as virus-like particles (VLPs). Using salivary and carbohydrate-binding assays, we showed that GII.4 VLP-carbohydrate ligand binding patterns have changed over time and include carbohydrates regulated by the human FUT2 and FUT3 pathways, suggesting that strain sensitivity to human susceptibility alleles will vary. Variation in surface-exposed residues and in residues that surround the fucose ligand interaction domain suggests that antigenic drift may promote GII.4 persistence in human populations. Evidence supporting antigenic drift was obtained by measuring the antigenic relatedness of GII.4 VLPs using murine and human sera and demonstrating strain-specific serologic and carbohydrate-binding blockade responses. These data suggest that the GII.4 noroviruses persist by altering their HBGA carbohydrate-binding targets over time, which not only allows for escape from highly penetrant host susceptibility alleles, but simultaneously allows for immune-driven selection in the receptor-binding region to facilitate escape from protective herd immunity. Conclusions Our data suggest that the surface-exposed carbohydrate ligand binding domain in the norovirus capsid is under heavy immune selection and likely evolves by antigenic drift in the face of human herd immunity. Variation in the capsid carbohydrate-binding domain is tolerated because of the large repertoire of similar, yet distinct HBGA carbohydrate receptors available on mucosal surfaces that could interface with the remodeled architecture of the capsid ligand-binding pocket. The continuing evolution of new replacement strains suggests that, as with influenza viruses, vaccines could be targeted that protect against norovirus infections, and that continued epidemiologic surveillance and reformulations of norovirus vaccines will be essential in the control of future outbreaks. PMID:18271619

  20. What Is the Reservoir of Emergent Human Norovirus Strains?

    PubMed Central

    Baric, Ralph S.

    2015-01-01

    Since 1996, there have been at least six human norovirus pandemics. All of the pandemic strains are genetically related, segregating in the genogroup II, genotype 4 (GII.4) cluster within the Norovirus genus. Evidence indicates that these strains are closely related but antigenically distinct, supporting immune-driven viral evolution. Thus, norovirus vaccines will likely require periodic reformulation to protect from newly emergent strains. A major obstacle is that the reservoir of emergent strains is unknown. Noroviruses display tight species specificity and there is no evidence supporting zoonotic transmission, so an animal reservoir is considered unlikely. Moreover, available data indicate minimal viral diversity in most natural human infections. In this Gem, we discuss the widely speculated idea that chronically infected immunocompromised individuals are norovirus reservoirs and provide a rationale for the theory that elderly and malnourished hosts may also represent norovirus reservoirs. PMID:25787285

  1. Structural Basis for Norovirus Inhibition by Human Milk Oligosaccharides

    PubMed Central

    Weichert, Stefan; Koromyslova, Anna; Singh, Bishal K.; Hansman, Satoko; Jennewein, Stefan; Schroten, Horst

    2016-01-01

    Histo-blood group antigens (HBGAs) are important binding factors for norovirus infections. We show that two human milk oligosaccharides, 2′-fucosyllactose (2′FL) and 3-fucosyllactose (3FL), could block norovirus from binding to surrogate HBGA samples. We found that 2′FL and 3FL bound at the equivalent HBGA pockets on the norovirus capsid using X-ray crystallography. Our data revealed that 2′FL and 3FL structurally mimic HBGAs. These results suggest that 2′FL and 3FL might act as naturally occurring decoys in humans. PMID:26889023

  2. Identification of the novel Kawasaki 2014 GII.17 human norovirus strain in Italy, 2015.

    PubMed

    Medici, Maria Cristina; Tummolo, Fabio; Calderaro, Adriana; Chironna, Maria; Giammanco, Giovanni Maurizio; De Grazia, Simona; Arcangeletti, Maria Cristina; De Conto, Flora; Chezzi, Carlo; Martella, Vito

    2015-01-01

    Surveillance of noroviruses in Italy identified the novel GII.17 human norovirus strain, Kawasaki 2014, in February 2015. This novel strain emerged as a major cause of gastroenteritis in Asia during 2014/15, replacing the pandemic GII.4 norovirus strain Sydney 2012, but being reported only sporadically elsewhere. This novel strain is undergoing fast diversification and continuous monitoring is important to understand the evolution of noroviruses and to implement the future strategies on norovirus vaccines.

  3. Molecular Diagnostic Methods for Detection and Characterization of Human Noroviruses

    PubMed Central

    Chen, Haifeng; Hu, Yuan

    2016-01-01

    Human noroviruses are a group of viral agents that afflict people of all age groups. The viruses are now recognized as the most common causative agent of nonbacterial acute gastroenteritis and foodborne viral illness worldwide. However, they have been considered to play insignificant roles in the disease burden of acute gastroenteritis for the past decades until the recent advent of new and more sensitive molecular diagnostic methods. The availability and application of the molecular diagnostic methods have led to enhanced detection of noroviruses in clinical, food and environmental samples, significantly increasing the recognition of noroviruses as an etiologic agent of epidemic and sporadic acute gastroenteritis. This article aims to summarize recent efforts made for the development of molecular methods for the detection and characterization of human noroviruses. PMID:27335620

  4. Human noroviruses recognize sialyl Lewis x neoglycoprotein.

    PubMed

    Rydell, Gustaf E; Nilsson, Jonas; Rodriguez-Diaz, Jesus; Ruvoën-Clouet, Nathalie; Svensson, Lennart; Le Pendu, Jacques; Larson, Göran

    2009-03-01

    The carbohydrate binding characteristics of a norovirus GII.3 (Chron1) and a GII.4 (Dijon) strain were investigated using virus-like particles (VLPs) and saliva samples from 81 individuals genotyped for FUT2 (secretor) and FUT3 (Lewis) and phenotyped for ABO and Lewis blood groups. The two VLPs showed a typical secretor-gene-dependent binding and bound significantly stronger to saliva from A, B, and AB than from O individuals (P < 0.0001 and P < 0.001) but did not bind to any samples from secretor-negative individuals. The GII.3 strain showed larger interindividual variation and bound stronger to saliva from B than from A(2) secretors (P < 0.01). When assaying for binding to neoglycoproteins, the GII.3 and GII.4 strains were compared with the Norwalk GI.1 prototype strain. Although all three strains bound to Lewis b (and H type 1 chain) glycoconjugates, only the two GII strains showed an additional binding to sialyl Lewis x. This novel binding was specific since the VLPs did not bind to structural analogs, e.g., Lewis x or sialyl Lewis a, but only to sialyl Lewis x, sialyl diLewis x and sialylated type 2 chain conjugates. In inhibition experiments, the sialyl Lewis x conjugate was the most potent inhibitor. The minimal requirement for this potential receptor structure is Neu5Ac alpha 3Gal beta 4(Fuc alpha 3)GlcNAc beta 3Gal beta- where Fuc is not absolutely necessary for binding. Our study shows that some human norovirus GII strains have at least two binding specificities: one secretor-gene-dependent related to alpha1,2-fucosylated carbohydrates and another related to alpha2,3-sialylated carbohydrates of the type 2 chain, e.g., sialyl Lewis x.

  5. Comprehensive Comparison of Cultivable Norovirus Surrogates in Response to Different Inactivation and Disinfection Treatments

    PubMed Central

    Cromeans, Theresa; Park, Geun Woo; Costantini, Veronica; Lee, David; Wang, Qiuhong; Farkas, Tibor; Lee, Alvin

    2014-01-01

    Human norovirus is the leading cause of epidemic and sporadic acute gastroenteritis. Since no cell culture method for human norovirus exists, cultivable surrogate viruses (CSV), including feline calicivirus (FCV), murine norovirus (MNV), porcine enteric calicivirus (PEC), and Tulane virus (TuV), have been used to study responses to inactivation and disinfection methods. We compared the levels of reduction in infectivities of CSV and Aichi virus (AiV) after exposure to extreme pHs, 56°C heating, alcohols, chlorine on surfaces, and high hydrostatic pressure (HHP), using the same matrix and identical test parameters for all viruses, as well as the reduction of human norovirus RNA levels under these conditions. At pH 2, FCV was inactivated by 6 log10 units, whereas MNV, TuV, and AiV were resistant. All CSV were completely inactivated at 56°C within 20 min. MNV was inactivated 5 log10 units by alcohols, in contrast to 2 and 3 log10 units for FCV and PEC, respectively. TuV and AiV were relatively insensitive to alcohols. FCV was reduced 5 log10 units by 1,000 ppm chlorine, in contrast to 1 log10 unit for the other CSV. All CSV except FCV, when dried on stainless steel surfaces, were insensitive to 200 ppm chlorine. HHP completely inactivated FCV, MNV, and PEC at ≥300 MPa, and TuV at 600 MPa, while AiV was completely resistant to HHP up to 800 MPa. By reverse transcription-quantitative PCR (RT-qPCR), genogroup I (GI) noroviruses were more sensitive than GII noroviruses to alcohols, chlorine, and HHP. Although inactivation profiles were variable for each treatment, TuV and MNV were the most resistant CSV overall and therefore are the best candidates for studying the public health outcomes of norovirus infections. PMID:25015883

  6. Human norovirus culture in B cells

    PubMed Central

    Jones, Melissa K; Grau, Katrina R; Costantini, Veronica; Kolawole, Abimbola O; de Graaf, Miranda; Freiden, Pamela; Graves, Christina L; Koopmans, Marion; Wallet, Shannon M; Tibbetts, Scott A; Schultz-Cherry, Stacey; Wobus, Christiane E; Vinjé, Jan; Karst, Stephanie M

    2015-01-01

    Human noroviruses (HunoVs) are a leading cause of foodborne disease and severe childhood diarrhea, and they cause a majority of the gastroenteritis outbreaks worldwide. However, the development of effective and long-lasting HunoV vaccines and therapeutics has been greatly hindered by their uncultivability. We recently demonstrated that a HunoV replicates in human B cells, and that commensal bacteria serve as a cofactor for this infection. In this protocol, we provide detailed methods for culturing the GII.4-sydney HunoV strain directly in human B cells, and in a coculture system in which the virus must cross a confluent epithelial barrier to access underlying B cells. We also describe methods for bacterial stimulation of HunoV B cell infection and for measuring viral attachment to the surface of B cells. Finally, we highlight variables that contribute to the efficiency of viral replication in this system. Infection assays require 3 d and attachment assays require 3 h. analysis of infection or attachment samples, including rna extraction and rt-qpcr, requires ~6 h. PMID:26513671

  7. A gnotobiotic pig model for determining human norovirus inactivation by high-pressure processing

    USDA-ARS?s Scientific Manuscript database

    Human norovirus (NoV) is responsible for over 90 percent of outbreaks of acute nonbacterial gastroenteritis worldwide, and accounts for 60 percent of foodborne illness in the US. Currently, the infectivity of human NoVs is poorly understood due to the lack of a cell culture system. In this study, w...

  8. Identification of environmental determinants for spatio-temporal patterns of norovirus outbreaks in Korea using a geographic information system and binary response models.

    PubMed

    Kim, Jin Hwi; Lee, Dong Hoon; Joo, Yongsung; Zoh, Kyung Duk; Ko, Gwangpyo; Kang, Joo-Hyon

    2016-11-01

    Although norovirus outbreaks are well-recognized to have strong winter seasonality relevant to low temperature and humidity, the role of artificial human-made features within geographical areas in norovirus outbreaks has rarely been studied. The aim of this study is to assess the natural and human-made environmental factors favoring the occurrence of norovirus outbreaks using nationwide surveillance data. We used a geographic information system and binary response models to examine whether the norovirus outbreaks are spatially patterned and whether these patterns are associated with specific environmental variables including service levels of water supply and sanitation systems and land-use types. The results showed that small-scale low-tech local sewage treatment plants and winter sports areas were statistically significant factors favoring norovirus outbreaks. Compactness of the land development also affected the occurrence of norovirus outbreaks; transportation, water, and forest land-uses were less favored for effective transmission of norovirus, while commercial areas were associated with an increased rate of norovirus outbreaks. We observed associations of norovirus outbreaks with various outcomes of human activities, including discharge of poorly treated sewage, overcrowding of people during winter season, and compactness of land development, which might help prioritize target regions and strategies for the management of norovirus outbreaks.

  9. Enteric bacteria promote human and mouse norovirus infection of B cells

    PubMed Central

    Jones, Melissa K.; Watanabe, Makiko; Zhu, Shu; Graves, Christina L.; Keyes, Lisa R.; Grau, Katrina R.; Gonzalez-Hernandez, Mariam B.; Iovine, Nicole M.; Wobus, Christiane E.; Vinjé, Jan; Tibbetts, Scott A.; Wallet, Shannon M.; Karst, Stephanie M.

    2015-01-01

    The cell tropism of human noroviruses and the development of an in vitro infection model remain elusive. Although susceptibility to individual human norovirus strains correlates with an individual’s histo-blood group antigen (HBGA) profile, the biological basis of this restriction is unknown. We demonstrate that human and mouse noroviruses infected B cells in vitro and likely in vivo. Human norovirus infection of B cells required the presence of HBGA-expressing enteric bacteria. Furthermore, mouse norovirus replication was reduced in vivo when the intestinal microbiota was depleted by means of oral antibiotic administration. Thus, we have identified B cells as a cellular target of noroviruses and enteric bacteria as a stimulatory factor for norovirus infection, leading to the development of an in vitro infection model for human noroviruses. PMID:25378626

  10. Sanitizer Efficacy against Murine Norovirus, a Surrogate for Human Norovirus, on Stainless Steel Surfaces when Using Three Application Methods

    PubMed Central

    Kotwal, Grishma; Harrison, Mark A.; Law, S. Edward; Harrison, Judy A.

    2013-01-01

    Human noroviruses are major etiologic agents of epidemic gastroenteritis. Outbreaks are often accompanied by contamination of environmental surfaces, but since these viruses cannot be routinely propagated in laboratory cultures, their response to surface disinfectants is predicted by using surrogates, such as murine norovirus 1 (MNV-1). This study compared the virucidal efficacies of various liquid treatments (three sanitizer liquids, 5% levulinic acid plus 2% SDS [LEV/SDS], 200 ppm chlorine, and an isopropanol-based quaternary ammonium compound [Alpet D2], and two control liquids, sterile tap water and sterile tap water plus 2% SDS) when delivered to MNV-1-inoculated stainless steel surfaces by conventional hydraulic or air-assisted, induction-charged (AAIC) electrostatic spraying or by wiping with impregnated towelettes. For the spray treatments, LEV/SDS proved effective when applied with hydraulic and AAIC electrostatic spraying, providing virus reductions of 2.71 and 1.66 log PFU/ml, respectively. Alpet D2 provided a 2.23-log PFU/ml reduction with hydraulic spraying, outperforming chlorine (1.16-log PFU/ml reduction). Chlorine and LEV/SDS were equally effective as wipes, reducing the viral load by 7.05 log PFU/ml. Controls reduced the viral load by <1 log with spraying applications and by >3 log PFU/ml with wiping. Results indicated that both sanitizer type and application methods should be carefully considered when choosing a surface disinfectant to best prevent and control environmental contamination by noroviruses. PMID:23263949

  11. Broad Blockade Antibody Responses in Human Volunteers after Immunization with a Multivalent Norovirus VLP Candidate Vaccine: Immunological Analyses from a Phase I Clinical Trial

    PubMed Central

    Lindesmith, Lisa C.; Ferris, Martin T.; Mullan, Clancy W.; Ferreira, Jennifer; Debbink, Kari; Swanstrom, Jesica; Richardson, Charles; Goodwin, Robert R.; Baehner, Frank; Mendelman, Paul M.; Bargatze, Robert F.; Baric, Ralph S.

    2015-01-01

    Background Human noroviruses (NoVs) are the primary cause of acute gastroenteritis and are characterized by antigenic variation between genogroups and genotypes and antigenic drift of strains within the predominant GII.4 genotype. In the context of this diversity, an effective NoV vaccine must elicit broadly protective immunity. We used an antibody (Ab) binding blockade assay to measure the potential cross-strain protection provided by a multivalent NoV virus-like particle (VLP) candidate vaccine in human volunteers. Methods and Findings Sera from ten human volunteers immunized with a multivalent NoV VLP vaccine (genotypes GI.1/GII.4) were analyzed for IgG and Ab blockade of VLP interaction with carbohydrate ligand, a potential correlate of protective immunity to NoV infection and illness. Immunization resulted in rapid rises in IgG and blockade Ab titers against both vaccine components and additional VLPs representing diverse strains and genotypes not represented in the vaccine. Importantly, vaccination induced blockade Ab to two novel GII.4 strains not in circulation at the time of vaccination or sample collection. GII.4 cross-reactive blockade Ab titers were more potent than responses against non-GII.4 VLPs, suggesting that previous exposure history to this dominant circulating genotype may impact the vaccine Ab response. Further, antigenic cartography indicated that vaccination preferentially activated preexisting Ab responses to epitopes associated with GII.4.1997. Study interpretations may be limited by the relevance of the surrogate neutralization assay and the number of immunized participants evaluated. Conclusions Vaccination with a multivalent NoV VLP vaccine induces a broadly blocking Ab response to multiple epitopes within vaccine and non-vaccine NoV strains and to novel antigenic variants not yet circulating at the time of vaccination. These data reveal new information about complex NoV immune responses to both natural exposure and to vaccination, and

  12. Inactivation of a Human Norovirus Surrogate, Human Norovirus Virus-Like Particles, and Vesicular Stomatitis Virus by Gamma Irradiation ▿

    PubMed Central

    Feng, Kurtis; Divers, Erin; Ma, Yuanmei; Li, Jianrong

    2011-01-01

    Gamma irradiation is a nonthermal processing technology that has been used for the preservation of a variety of food products. This technology has been shown to effectively inactivate bacterial pathogens. Currently, the FDA has approved doses of up to 4.0 kGy to control food-borne pathogens in fresh iceberg lettuce and spinach. However, whether this dose range effectively inactivates food-borne viruses is less understood. We have performed a systematic study on the inactivation of a human norovirus surrogate (murine norovirus 1 [MNV-1]), human norovirus virus-like particles (VLPs), and vesicular stomatitis virus (VSV) by gamma irradiation. We demonstrated that MNV-1 and human norovirus VLPs were resistant to gamma irradiation. For MNV-1, only a 1.7- to 2.4-log virus reduction in fresh produce at the dose of 5.6 kGy was observed. However, VSV was more susceptible to gamma irradiation, and a 3.3-log virus reduction at a dose of 5.6 kGy in Dulbecco's modified Eagle medium (DMEM) was achieved. We further demonstrated that gamma irradiation disrupted virion structure and degraded viral proteins and genomic RNA, which resulted in virus inactivation. Using human norovirus VLPs as a model, we provide the first evidence that the capsid of human norovirus has stability similar to that of MNV-1 after exposure to gamma irradiation. Overall, our results suggest that viruses are much more resistant to irradiation than bacterial pathogens. Although gamma irradiation used to eliminate the virus contaminants in fresh produce by the FDA-approved irradiation dose limits seems impractical, this technology may be practical to inactivate viruses for other purposes, such as sterilization of medical equipment. PMID:21441330

  13. Human Norovirus Evolution in a Chronically Infected Host

    PubMed Central

    Doerflinger, Sylvie Y.; Weichert, Stefan; Koromyslova, Anna; Chan, Martin; Schwerk, Christian; Adam, Ruediger; Jennewein, Stefan

    2017-01-01

    ABSTRACT Typically, human noroviruses cause symptoms of acute gastroenteritis for 2 to 4 days. Often, the virions are shed in stool for several days after the symptoms recede, which in turn can lead to further contamination and transmission. Moreover, a number of reports have considered that chronic norovirus infections, i.e., lasting months and years, might even function as reservoirs for the generation of novel strains that can escape the herd immunity or have modified binding interactions with histo-blood group antigens (HBGAs). In this study, we analyzed noroviruses isolated from a patient who has presented a chronic infection for more than 6 years. We found that the isolated capsid sequences clustered into two main genetic types (termed A and B), despite a plethora of capsid quasi-sequences. Furthermore, the two genetic types corresponded well with distinct antigenicities. On the other hand, we showed that numerous amino acid substitutions on the capsid surface of genetic types A and B did not alter the HBGA binding profiles. However, divergent binding profiles for types A and B were observed with human milk oligosaccharides (HMOs), which structurally mimic HBGAs and may act as natural antivirals. Importantly, the isolated capsid sequences only had approximately 90% amino acid identity with other known sequences, which suggested that transmission of these chronic noroviruses could be limited. IMPORTANCE The norovirus genogroup II genotype 4 (GII.4) variants have approximately 5% divergence in capsid amino acid identity and have dominated over the past decade. The precise reason(s) for the GII.4 emergence and persistence in the human population is still unknown, but some studies have suggested that chronically infected patients might generate novel variants that can cause new epidemics. We examined GII.4 noroviruses isolated from an immunocompromised patient with a long-term infection. Numerous norovirus capsid quasi-species were isolated during the 13-month

  14. Variable high pressure processing sensitivities for GII human noroviruses

    USDA-ARS?s Scientific Manuscript database

    Human norovirus (HuNoV) is the leading cause of foodborne diseases worldwide. High pressure processing (HPP) is one of the most promising non-thermal technologies for decontamination of viral pathogens in foods. However, the survival of HuNoVs by HPP is poorly understood because these viruses cann...

  15. Low-density microarray technologies for rapid human norovirus genotyping

    USDA-ARS?s Scientific Manuscript database

    Human noroviruses cause up to 21 million cases of foodborne disease in the United States annually and are the most common cause of acute gastroenteritis in industrialized countries. To reduce the burden of foodborne disease associated with viruses, the use of low density DNA microarrays in conjuncti...

  16. Inactivation of Tulane virus, a novel surrogate for human norovirus

    USDA-ARS?s Scientific Manuscript database

    Human noroviruses (HuNoVs) are the major cause of non-bacterial epidemics of gastroenteritis. Due to the inability to cultivate HuNoVs and the lack of an efficient small animal model, surrogates are used to study HuNoV biology. Two such surrogates, the feline calicivirus (FCV) and the murine norovir...

  17. Human Norovirus Interactions with Histo-Blood Group Antigens and Human Milk Oligosaccharides

    PubMed Central

    Schroten, Horst; Hanisch, Franz-Georg

    2016-01-01

    Human noroviruses interact with both human histo-blood group antigens (HBGAs) and human milk oligosaccharides (HMOs). The former are believed to be important for a virus infection, while the latter might act as natural decoys in the host during an infection. However, certain noroviruses are known to bind poorly to HBGAs and yet still cause infections; some interact with numerous HBGA types but are nonprevalent; and yet others bind HBGAs and seem to be increasing in prevalence. HBGAs and HMOs can be found as soluble antigens in humans, can be structurally alike, and can interact with equivalent residues at identical binding pockets on the capsid. In this Gem, we discuss HBGA and HMO binding studies for human noroviruses, concentrating on the clinically important genogroup II noroviruses. In short, the roles of HBGA and HMO interactions in norovirus infections are still unclear. PMID:27122582

  18. High pressure inactivation of human norovirus-like particles: evidence that the capsid of human norovirus is highly pressure resistant

    USDA-ARS?s Scientific Manuscript database

    High pressure processing (HPP) is a promising non-thermal technology to inactivate foodborne viruses. However, the effectiveness of HPP on inactivating human norovirus (HuNoV), the leading cause of acute gastroenteritis, is unknown because it cannot be propagated in cell culture. Therefore, developi...

  19. Determination of the thermal inactivation kinetics of the human norovirus surrogates, murine norovirus and feline calicivirus.

    PubMed

    Bozkurt, Hayriye; D'Souza, Doris H; Davidson, P Michael

    2013-01-01

    Studies are needed to bridge existing data gaps and determine appropriate parameters for thermal inactivation methods for human noroviruses. Cultivable surrogates, such as feline calicivirus (FCV-F9) and murine norovirus (MNV-1), have been used in the absence of human norovirus infectivity assays. This study aimed to characterize the thermal inactivation kinetics of MNV-1 and FCV-F9 at 50, 56, 60, 65, and 72°C for different treatment times (0 to 60 min). Thermal inactivation was performed using the capillary tube method with titers of 4.0 × 10(7) (MNV-1) and 5.8 × 10(8) (FCV-F9) PFU/ml in triplicate experiments, followed by standard plaque assays in duplicate for each experiment. Weibull and first-order models were compared to describe survival curve kinetics. Model fitness was investigated by comparing the regression coefficients (R(2)) and the chi-square (χ(2)) and root mean square error (RMSE) values. The D-values calculated from the first-order model (50 to 72°C) were 0.15 to 34.49 min for MNV-1 and 0.11 to 20.23 min for FCV-9. Using the Weibull model, the t(D) values needed to destroy 1 log PFU of MNV-1 and FCV-F9 at the same temperatures were 0.11 to 28.26 and 0.06 to 13.86 min, respectively. In terms of thermal resistance, MNV-1 was more sensitive than FCV-F9 up to 65°C. At 72°C, FCV-F9 was slightly more susceptible to heat inactivation. Results revealed that the Weibull model was more appropriate to represent the thermal inactivation behavior of both tested surrogates. The z-values were calculated using D-values for the first-order model and the t(D) values for the Weibull model. The z-values were 9.31 and 9.19°C for MNV-1 and 9.36 and 9.31°C for FCV-F9 for the first-order and Weibull models, respectively. This study provides more precise information than previous reports on the thermal inactivation kinetics of two norovirus surrogates for use in thermal process calculations.

  20. The virucidal effects against murine norovirus and feline calicivirus F4 as surrogates for human norovirus by the different additive concentrations of ethanol-based sanitizers.

    PubMed

    Akasaka, Tempei; Shimizu-Onda, Yuko; Hayakawa, Satoshi; Ushijima, Hiroshi

    2016-03-01

    Since human norovirus is non-cultivable, murine norovirus and feline calicivirus have been used as surrogates. In this study, the virucidal effects of ethanol-based sanitizers with different concentrations of additives (malic acid/sodium malate, glycerin-fatty acid ester) against murine norovirus and feline calicivirus F4 were examined. The ethanol-based sanitizers at pH 7 showed sufficient virucidal effects, but glycerin-fatty acid ester included in ethanol-based sanitizers at pH 4 or 6 reduced the virucidal effects against murine norovirus. The ethanol-based sanitizers containing malic acid/sodium malate inactivated feline calicivirus F4 in shorter time, but there is no difference between ethanol-based sanitizers with and without glycerin-fatty acid ester. Traditionally, feline calicivirus has been used for long time as a surrogate virus for human norovirus. However, this study suggested that murine norovirus and feline calicivirus F4 had different sensitivity with the additive components of ethanol-based sanitizers. Therefore, using feline calicivirus alone as a surrogate for human norovirus may not be sufficient to evaluate the virucidal effect of sanitizers on food-borne infections caused by human norovirus. Sanitizers having virucidal effects against at least both murine norovirus and feline calicivirus may be more suitable to inactivate human norovirus.

  1. Comparative Evaluation of Real-Time PCR Methods for Human Noroviruses in Wastewater and Human Stool

    PubMed Central

    Konta, Yoshimitsu; Kazama, Shinobu; Inaba, Manami; Imagawa, Toshifumi; Tohma, Kentaro; Saito, Mayuko; Suzuki, Akira; Oshitani, Hitoshi; Omura, Tatsuo

    2016-01-01

    Selecting the best quantitative PCR assay is essential to detect human norovirus genome effectively from clinical and environmental samples because no cell lines have been developed to propagate this virus. The real-time PCR methods for noroviruses GI (4 assays) and GII (3 assays) were evaluated using wastewater (n = 70) and norovirus-positive stool (n = 77) samples collected in Japan between 2012 and 2013. Standard quantitative PCR assays recommended by the U.S. Environmental Protection Agency, International Organization for Standardization, and Ministry of Health, Labour and Welfare, Japan, together with recently reported assays were included. Significant differences in positive rates and quantification cycles were observed by non-parametric analysis. The present study identifies the best assay for norovirus GI and GII to amplify norovirus genomes efficiently. PMID:27525654

  2. In Vitro Cell Culture Infectivity Assay for Human Noroviruses

    SciTech Connect

    Straub, Tim M.; Honer Zu Bentrup, Kerstin A.; Orosz Coghlan, Patricia A.; Dohnalkova, Alice; Mayer, Brooke K.; Bartholomew, Rachel A.; Valdez, Catherine O.; Bruckner-Lea, Cindy J.; Gerba, Charles P.; Abbaszadegan, Morteza; Nickerson, Cheryl A.

    2007-01-30

    Human noroviruses (NoV) cause severe, self-limiting gastroenteritis that typically lasts 24 - 48 hours. The true nature of NoV pathogenesis remains unknown due to the lack of suitable tissue culture or animal models. Here we show, for the first time, that NoV can infect and replicate in an organoid, three-dimensional (3-D) model of human small intestinal epithelium (INT-407). Cellular differentiation for this model was achieved by growing the cells in 3-D on porous collagen I-coated microcarrier beads under conditions of physiological fluid shear in rotating wall vessel bioreactors. Microscopy, PCR, and fluorescent in-situ hybridization were employed to provide evidence of NoV infection. CPE and norovirus RNA was detected at each of the five cell passages for both genogroup I and II viruses. Our results demonstrate that the highly differentiated 3-D cell culture model can support the natural growth of human noroviruses, whereas previous attempts using differentiated monolayer cultures failed.

  3. Human Norovirus Detection and Production, Quantification, and Storage of Virus-Like Particles

    PubMed Central

    Debbink, Kari; Costantini, Veronica; Swanstrom, Jesica; Agnihothram, Sudhakar; Vinjé, Jan; Baric, Ralph

    2014-01-01

    Human noroviruses constitute a significant worldwide disease burden. Each year noroviruses cause over 267 million infections, deaths in over 200,000 children under the age of five, and over 50% of U.S. food borne illness. Due to the absence of a tissue culture model or small animal model to study human norovirus, virus-like particles (VLPs) and ELISA-based biological assays have been used to answer questions about norovirus evolution and immunity as well provide a potential vaccine platform. This chapter outlines the protocols on norovirus detection in stool and norovirus VLP design, production, purification, and storage using a Venezuelan equine encephalitis virus (VEE)-based VRP expression system. PMID:24510290

  4. A survey of Australian oysters for the presence of human noroviruses.

    PubMed

    Brake, Felicity; Ross, Tom; Holds, Geoffrey; Kiermeier, Andreas; McLeod, Catherine

    2014-12-01

    Impending international policies for norovirus in oysters and the lack of Australian data suggested there was a need to undertake a national survey of norovirus in oysters. Two geographically distinct oyster-growing areas from each of three Australian states were sampled on 4 occasions during 2010 and 2011. The sites selected were considered by state shellfish authorities to be the most compromised with respect to the potential for human faecal contamination as identified by shoreline surveys. The oysters were tested for norovirus GI, GII and Escherichia coli. Norovirus GII was detected in two of 120 (1.7%) samples and norovirus GI was not detected. One of the norovirus positive samples was cloned and sequenced as GII.3. Five of 120 (4.2%) samples were found to have more than the guidance concentration of 230 E. coli per 100 g of shellfish but these samples did not contain detectable concentrations of norovirus. The apparently low prevalence of norovirus in oysters from Australian growing areas supports epidemiological data that suggests norovirus contamination of Australian oysters is rare. The results from this study emphasise the need for future norovirus control measures for shellfish to be commensurate with the risk associated with the growing area.

  5. Comparative Virucidal Efficacy of Seven Disinfectants Against Murine Norovirus and Feline Calicivirus, Surrogates of Human Norovirus.

    PubMed

    Zonta, William; Mauroy, Axel; Farnir, Frederic; Thiry, Etienne

    2016-03-01

    Human noroviruses (HuNoV) are the leading cause of acute non-bacterial gastroenteritis in humans and can be transmitted either by person-to-person contact or by consumption of contaminated food. A knowledge of an efficient disinfection for both hands and food-contact surfaces is helpful for the food sector and provides precious information for public health. The aim of this study was to evaluate the effect of seven disinfectants belonging to different groups of biocides (alcohol, halogen, oxidizing agents, quaternary ammonium compounds, aldehyde and biguanide) on infectious viral titre and on genomic copy number. Due to the absence of a cell culture system for HuNoV, two HuNoV surrogates, such as murine norovirus and feline calicivirus, were used and the tests were performed in suspension, on gloves and on stainless steel discs. When, as criteria of efficacy, a log reduction >3 of the infectious viral titre on both surrogates and in the three tests is used, the most efficacious disinfectants in this study appear to be biocidal products B, C and D, representing the halogens, the oxidizing agents group and a mix of QAC, alcohol and aldehyde, respectively. In addition, these three disinfectants also elicited a significant effect on genomic copy number for both surrogate viruses and in all three tests. The results of this study demonstrate that a halogen compound, oxidizing agents and a mix of QAC, alcohol and aldehyde are advisable for HuNoV disinfection of either potentially contaminated surfaces or materials in contact with foodstuffs.

  6. Temperature-dependent persistence of human norovirus within oysters (Crassotrea virginica)

    USDA-ARS?s Scientific Manuscript database

    This study characterizes the persistence of human norovirus in Eastern oysters (Crassostrea virginica) held at different seawater temperatures. Oysters were contaminated with human norovirus GI.1 (Norwalk strain 8fIIa) by exposing them to virus contaminated water at 15 degrees C, and subsequently ho...

  7. High hydrostatic pressure inactivation of murine norovirus and human noroviruses on green onions and in salsa.

    PubMed

    Sido, Robert F; Huang, Runze; Liu, Chuhan; Chen, Haiqiang

    2017-02-02

    In this study, high hydrostatic pressure (HHP) was evaluated as an intervention for human noroviruses (HuNoVs) in green onions and salsa. To determine the effect of water during HHP treatment on virus inactivation, a HuNoV surrogate, murine norovirus 1 (MNV-1), was inoculated onto green onions and then HHP-treated at 350MPa with or without water at 4 or 20°C. The presence of water enhanced HHP inactivation of MNV-1 on green onions at 4°C but not at 20°C. To test the temperature effect on HHP inactivation of MNV-1, inoculated green onions were HHP-treated at 300MPa at 1, 4 and 10°C. As the temperature decreased, MNV-1 became more sensitive to HHP treatment. HHP inactivation curves of MNV-1 on green onions and salsa were obtained at 300 or 350MPa for 0.5-3min at 1°C. All three inactivation curves showed a linear relationship between log reduction of MNV-1 and time. D values of HHP inactivation of MNV-1 on green onions were 1.10 and 0.61min at 300 and 350MPa, respectively. The D value of HHP inactivation of MNV-1 in salsa at 300MPa was 0.63min. HHP inactivation of HuNoV GI.1 and GII.4 on green onions and salsa was also conducted. To achieve >3 log reduction of HuNoV GI.1, HHP treatments for 2min at 1°C should be conducted at 600MPa and 500MPa for green onions and salsa, respectively. To achieve >3 log reduction of HuNoV GII.4, HHP treatments for 2min at 1°C should be conducted at 500MPa and 300MPa for green onions and salsa, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Development of a Recombinase Polymerase Amplification Assay for Detection of Epidemic Human Noroviruses.

    PubMed

    Moore, Matthew D; Jaykus, Lee-Ann

    2017-01-09

    Human norovirus is a leading cause of viral gastroenteritis worldwide. Rapid detection could facilitate control, however widespread point-of-care testing is infrequently done due to the lack of robust and portable methods. Recombinase polymerase amplification (RPA) is a novel isothermal method which rapidly amplifies and detects nucleic acids using a simple device in near real-time. An RT-RPA assay targeting a recent epidemic human norovirus strain (GII.4 New Orleans) was developed and evaluated in this study. The assay successfully detected purified norovirus RNA from multiple patient outbreak isolates and had a limit of detection of 3.40 ± 0.20 log10 genomic copies (LGC), which is comparable to most other reported isothermal norovirus amplification methods. The assay also detected norovirus in directly boiled stool, and displayed better resistance to inhibitors than a commonly used RT-qPCR assay. The assay was specific, as it did not amplify genomes from 9 non-related enteric viruses and bacteria. The assay detected norovirus in some samples in as little as 6 min, and the entire detection process can be performed in less than 30 min. The reported RT-RPA method shows promise for sensitive point-of-care detection of epidemic human norovirus, and is the fastest human norovirus amplification method to date.

  9. Development of a Recombinase Polymerase Amplification Assay for Detection of Epidemic Human Noroviruses

    PubMed Central

    Moore, Matthew D.; Jaykus, Lee-Ann

    2017-01-01

    Human norovirus is a leading cause of viral gastroenteritis worldwide. Rapid detection could facilitate control, however widespread point-of-care testing is infrequently done due to the lack of robust and portable methods. Recombinase polymerase amplification (RPA) is a novel isothermal method which rapidly amplifies and detects nucleic acids using a simple device in near real-time. An RT-RPA assay targeting a recent epidemic human norovirus strain (GII.4 New Orleans) was developed and evaluated in this study. The assay successfully detected purified norovirus RNA from multiple patient outbreak isolates and had a limit of detection of 3.40 ± 0.20 log10 genomic copies (LGC), which is comparable to most other reported isothermal norovirus amplification methods. The assay also detected norovirus in directly boiled stool, and displayed better resistance to inhibitors than a commonly used RT-qPCR assay. The assay was specific, as it did not amplify genomes from 9 non-related enteric viruses and bacteria. The assay detected norovirus in some samples in as little as 6 min, and the entire detection process can be performed in less than 30 min. The reported RT-RPA method shows promise for sensitive point-of-care detection of epidemic human norovirus, and is the fastest human norovirus amplification method to date. PMID:28067278

  10. Human norovirus binding to select bacteria representative of the human gut microbiota

    PubMed Central

    Almand, Erin A.; Outlaw, Janie; Jaykus, Lee-Ann

    2017-01-01

    Recent reports describe the ability of select bacterial strains to bind human norovirus, although the specificity of such interactions is unknown. The purpose of this work was to determine if a select group of bacterial species representative of human gut microbiota bind to human norovirus, and if so, to characterize the intensity and location of that binding. The bacteria screened included naturally occurring strains isolated from human stool (Klebsiella spp., Citrobacter spp., Bacillus spp., Enterococcus faecium and Hafnia alvei) and select reference strains (Staphylococcus aureus and Enterobacter cloacae). Binding in PBS was evaluated to three human norovirus strains (GII.4 New Orleans 2009 and Sydney 2012, GI.6) and two surrogate viruses (Tulane virus and Turnip Crinkle Virus (TCV)) using a suspension assay format linked to RT-qPCR for quantification. The impact of different overnight culture media prior to washing on binding efficiency in PBS was also evaluated, and binding was visualized using transmission electron microscopy. All bacteria tested bound the representative human norovirus strains with high efficiency (<1 log10 of input virus remained unbound or <10% unbound and >90% binding efficiency) (p>0.05); there was selective binding for Tulane virus and no binding observed for TCV. Binding efficiency was highest when bacteria were cultured in minimal media (<1 log10 of input virus remained unbound, so >90% bound), but notably decreased when cultured in enriched media (1–3 log10 unbound or 0.01 –<90% bound)) (p<0.05). The norovirus-bacteria binding occurred around the outer cell surfaces and pili structures, without apparent localization. The findings reported here further elucidate and inform the dynamics between human noroviruses and enteric bacteria with implications for norovirus pathogenesis. PMID:28257478

  11. Human norovirus binding to select bacteria representative of the human gut microbiota.

    PubMed

    Almand, Erin A; Moore, Matthew D; Outlaw, Janie; Jaykus, Lee-Ann

    2017-01-01

    Recent reports describe the ability of select bacterial strains to bind human norovirus, although the specificity of such interactions is unknown. The purpose of this work was to determine if a select group of bacterial species representative of human gut microbiota bind to human norovirus, and if so, to characterize the intensity and location of that binding. The bacteria screened included naturally occurring strains isolated from human stool (Klebsiella spp., Citrobacter spp., Bacillus spp., Enterococcus faecium and Hafnia alvei) and select reference strains (Staphylococcus aureus and Enterobacter cloacae). Binding in PBS was evaluated to three human norovirus strains (GII.4 New Orleans 2009 and Sydney 2012, GI.6) and two surrogate viruses (Tulane virus and Turnip Crinkle Virus (TCV)) using a suspension assay format linked to RT-qPCR for quantification. The impact of different overnight culture media prior to washing on binding efficiency in PBS was also evaluated, and binding was visualized using transmission electron microscopy. All bacteria tested bound the representative human norovirus strains with high efficiency (<1 log10 of input virus remained unbound or <10% unbound and >90% binding efficiency) (p>0.05); there was selective binding for Tulane virus and no binding observed for TCV. Binding efficiency was highest when bacteria were cultured in minimal media (<1 log10 of input virus remained unbound, so >90% bound), but notably decreased when cultured in enriched media (1-3 log10 unbound or 0.01 -<90% bound)) (p<0.05). The norovirus-bacteria binding occurred around the outer cell surfaces and pili structures, without apparent localization. The findings reported here further elucidate and inform the dynamics between human noroviruses and enteric bacteria with implications for norovirus pathogenesis.

  12. Recovery optimization and survival of human norovirus surrogates, feline calicivirus and murine norovirus on carpet.

    PubMed

    Buckley, David; Fraser, Angela; Huang, Guohui; Jiang, Xiuping

    2017-09-01

    Carpet been attributed to prolonged and reoccurring outbreaks of human noroviruses (HuNoV), the leading cause of acute gastroenteritis worldwide. Viral recovery from environmental surfaces, such as carpet, remains undeveloped. Our aim was to determine survival of HuNoV surrogates on an understudied environmental surface, carpet. First, we measured the zeta potential and absorption capacity of wool and nylon carpet fibers, then developed a mini-spin column elution method (MSC), and lastly characterized the survival of HuNoV surrogates, feline calicivirus (FCV) and murine norovirus (MNV), over 60 days under 30 and 70% relative humidity (RH) on two types of carpet and one glass surface. Carpet surface charge was negative between relevant pH values (7 - 9). Additionally, wool could absorb ca. 2X more liquid than nylon. Percent recovery efficiency with the MSC ranged from 4.34 to 20.89% and 30.71 to 54.14% for FCV and MNV on carpet fibers, respectively, after desiccation. Overall, elution buffer type did not significantly affect recovery. Infectious FCV or MNV survived between <1 and 15 or 3 and 15 days, respectively. However, MNV survived longer under some conditions and at significantly (P <0.05) higher titers compared to FCV. Albeit, surrogates followed similar survival trends, i.e. both survived longest on wool then nylon and glass while 30% RH provided a more hospitable environment compared to 70% RH. RT-qPCR signals for both surrogates were detectable for the entire study but FCV genomic copies experienced significantly higher reductions (<3.80 log10 copies) on all surfaces compared to MNV (<1.10 log10 copies).IMPORTANCE Human noroviruses (HuNoV) are the leading cause of acute gastroenteritis worldwide. Classical symptoms of illness include vomiting and diarrhea which could lead to severe dehydration and death. HuNoV are transmitted by the fecal-oral or vomitus-oral route via person-to-person, food, water, and/or environmental surfaces. Published laboratory

  13. The molecular pathology of noroviruses.

    PubMed

    Karst, Stephanie M; Zhu, Shu; Goodfellow, Ian G

    2015-01-01

    Norovirus infection in humans typically results in acute gastroenteritis but may also occur in many animal species. Noroviruses are recognized as one of the most common causes of acute gastroenteritis in the world, being responsible for almost 20% of all cases. Despite their prevalence and impact, our knowledge of the norovirus life cycle and the pathological processes associated with norovirus-induced disease is limited. Whilst infection of the intestine is the norm, extraintestinal spread and associated pathologies have also been described. In addition, long-term chronic infections are now recognized as a significant cause of morbidity and mortality in the immunocompromised. This review aims to summarize the current state of knowledge with respect to norovirus pathology and the underlying mechanisms that have been characterized to date.

  14. Human Norovirus prevalence in Africa: a review of studies from 1990 to 2013.

    PubMed

    Kabue, Jean Pierre; Meader, Emma; Hunter, Paul R; Potgieter, Natasha

    2016-01-01

    To assess the contribution of Human Norovirus to diarrhoeal diseases in Africa. We conducted a systematic review of the PubMed and EMBASE databases for published articles of Human Norovirus in Africa between 1990 and 2013. Data were extracted from selected studies and analysed. A total of 208 eligible studies were identified, of which 55 (from 19 countries) met the inclusion criteria. Many cases were of sporadic gastroenteritis (70.9%) in children (82%), 65.4% of which were seen in an outpatient setting. Over half (59.4%) of the affected children were under 5 years of age. The pooled prevalence rate of Human NoV was 11% (95% CI 8-14%), and the meta-analysis indicated significant heterogeneity between the studies. However, the conditional negative binomial regression could not clearly find the factors affecting the Human NoV prevalence rates reported. A close relationship was found between Human Norovirus strains from environmental and clinical samples. Unreported sporadic gastroenteritis cases of Human Norovirus are common in Africa. Most are community-associated infections. Possible environmental transmission routes have been documented. Combined environmental and clinical studies are required for targeted actions to control transmission of Human Norovirus in Africa. Systematic surveillance of Human Norovirus is needed to measure the burden of Norovirus-induced gastroenteritis in Africa and support any requirements for vaccine development. © 2015 John Wiley & Sons Ltd.

  15. Norovirus - hospital

    MedlinePlus

    Gastroenteritis - norovirus; Colitis - norovirus; Hospital acquired infection - norovirus ... fluids ( dehydration ). Anyone can become infected with norovirus. Hospital patients who are very old, very young, or ...

  16. Norovirus and other human enteric viruses in moroccan shellfish.

    PubMed

    Benabbes, Laila; Ollivier, Joanna; Schaeffer, Julien; Parnaudeau, Sylvain; Rhaissi, Houria; Nourlil, Jalal; Le Guyader, Françoise S

    2013-03-01

    The aim of this study was to evaluate the presence of human enteric viruses in shellfish collected along the Mediterranean Sea and Atlantic Coast of Morocco. A total of 77 samples were collected from areas potentially contaminated by human sewage. Noroviruses were detected in 30 % of samples, with an equal representation of GI and GII strains, but were much more frequently found in cockles or clams than in oysters. The method used, including extraction efficiency controls, allowed the quantification of virus concentration. As in previous reports, results showed levels of contamination between 100 and 1,000 copies/g of digestive tissues. Sapoviruses were detected in 13 % of samples mainly in oyster and clam samples. Hepatitis A virus was detected in two samples, with concentrations around 100 RNA copies/g of digestive tissues. Only two samples were contaminated with enterovirus and none with norovirus GIV or Aichi virus. This study highlights the interest of studying shellfish samples from different countries and different production areas. A better knowledge of shellfish contamination helps us to understand virus levels in shellfish and to improve shellfish safety, thus protecting consumers.

  17. High-Pressure Inactivation of Human Norovirus Virus-Like Particles Provides Evidence that the Capsid of Human Norovirus Is Highly Pressure Resistant

    PubMed Central

    Lou, Fangfei; Huang, Pengwei; Neetoo, Hudaa; Gurtler, Joshua B.; Niemira, Brendan A.; Chen, Haiqiang; Jiang, Xi

    2012-01-01

    Human norovirus (NoV) is the leading cause of nonbacterial acute gastroenteritis epidemics worldwide. High-pressure processing (HPP) has been considered a promising nonthermal processing technology to inactivate food- and waterborne viral pathogens. Due to the lack of an effective cell culture method for human NoV, the effectiveness of HPP in inactivating human NoV remains poorly understood. In this study, we evaluated the effectiveness of HPP in disrupting the capsid of human NoV based on the structural and functional integrity of virus-like particles (VLPs) and histo-blood group antigen (HBGA) receptor binding assays. We found that pressurization at 500 to 600 MPa for 2 min, a pressure level that completely inactivates murine norovirus and feline calicivirus, was not sufficient to disrupt the structure and function of human NoV VLPs, even with a holding time of 60 min. Degradation of VLPs increased commensurate with increasing pressure levels more than increasing time. The times required for complete disruption of human NoV VLPs at 700, 800, and 900 MPa were 45, 15, and 2 min, respectively. Human NoV VLPs were more resistant to HPP in their ability to bind type A than type B and O HBGAs. Additionally, the 23-nm VLPs appeared to be much more stable than the 38-nm VLPs. Taken together, our results demonstrated that the human NoV capsid is highly resistant to HPP. While human NoV VLPs may not be fully representative of viable human NoV, destruction of the VLP capsid is highly suggestive of a typical response for viable human NoV. PMID:22635990

  18. Efficacy of Neutral Electrolyzed Water for Inactivation of Human Norovirus.

    PubMed

    Moorman, Eric; Montazeri, Naim; Jaykus, Lee-Ann

    2017-08-15

    Human norovirus (NoV) is the leading cause of acute gastroenteritis worldwide. Persistence on surfaces and resistance to many conventional disinfectants contribute to widespread transmission of norovirus. We examined the efficacy of neutral electrolyzed water (NEW; pH 7) for inactivation of human NoV GII.4 Sydney in suspension (ASTM method 1052-11) and on stainless steel surfaces (ASTM method 1053-11) with and without an additional soil load. The impact of the disinfectant on viral capsid was assessed using reverse transcriptase quantitative PCR (RT-qPCR; with an RNase pretreatment), SDS-PAGE, transmission electron microscopy, and a histo-blood group antigen (HBGA) receptor-binding assay. These studies were done in parallel with those using Tulane virus (TuV), a cultivable human NoV surrogate. Neutral electrolyzed water at 250 ppm free available chlorine produced a 4.8- and 0.4-log10 reduction in NoV genome copy number after 1 min in suspension and on stainless steel, respectively. Increasing the contact time on surfaces to 5, 10, 15, and 30 min reduced human NoV genomic copies by 0.5, 1.6, 2.4, and 5.0 log10 and TuV infectious titers by 2.4, 3.0, 3.8, and 4.1 log10 PFU, respectively. Increased soil load effectively eliminated antiviral efficacy regardless of testing method and virus. Exposure to NEW induced a near complete loss of receptor binding (5 ppm, 30 s), degradation of VP1 major capsid protein (250 ppm, 5 min), and increased virus particle aggregation (150 ppm, 30 min). Neutral electrolyzed water at 250 ppm shows promise as an antinoroviral disinfectant when used on precleaned stainless steel surfaces.IMPORTANCE Norovirus is the leading cause of acute viral gastroenteritis worldwide. Transmission occurs by fecal-oral or vomitus-oral routes. The persistence of norovirus on contaminated environmental surfaces exacerbates its spread, as does its resistance to many conventional disinfectants. The purpose of this research was to evaluate the antinoroviral

  19. Production of Brazilian human norovirus VLPs and comparison of purification methods

    PubMed Central

    Lamounier, Thais Alves da Costa; de Oliveira, Layssa Miranda; de Camargo, Brenda Rabello; Rodrigues, Kelly Barreto; Noronha, Eliane Ferreira; Ribeiro, Bergmann Morais; Nagata, Tatsuya

    2015-01-01

    Abstract Noroviruses (NVs) are responsible for most cases of human nonbacterial gastroenteritis worldwide. Some parameters for the purification of NV virus-like particles (VLPs) such as ease of production and yield were studied for future development of vaccines and diagnostic tools. In this study, VLPs were produced by the expression of the VP1 and VP2 gene cassette of the Brazilian NV isolate, and two purification methods were compared: cesium chloride (CsCl) gradient centrifugation and ion-exchange chromatography (IEC). IEC produced more and purer VLPs of NV compared to CsCl gradient centrifugation. PMID:26691489

  20. Pathogenesis of noroviruses, emerging RNA viruses.

    PubMed

    Karst, Stephanie M

    2010-03-01

    Human noroviruses in the family Caliciviridae are a major cause of epidemic gastroenteritis. They are responsible for at least 95% of viral outbreaks and over 50% of all outbreaks worldwide. Transmission of these highly infectious plus-stranded RNA viruses occurs primarily through contaminated food or water, but also through person-to-person contact and exposure to fomites. Norovirus infections are typically acute and self-limited. However, disease can be much more severe and prolonged in infants, elderly, and immunocompromised individuals. Norovirus outbreaks frequently occur in semi-closed communities such as nursing homes, military settings, schools, hospitals, cruise ships, and disaster relief situations. Noroviruses are classified as Category B biodefense agents because they are highly contagious, extremely stable in the environment, resistant to common disinfectants, and associated with debilitating illness. The number of reported norovirus outbreaks has risen sharply since 2002 suggesting the emergence of more infectious strains. There has also been increased recognition that noroviruses are important causes of childhood hospitalization. Moreover, noroviruses have recently been associated with multiple clinical outcomes other than gastroenteritis. It is unclear whether these new observations are due to improved norovirus diagnostics or to the emergence of more virulent norovirus strains. Regardless, it is clear that human noroviruses cause considerable morbidity worldwide, have significant economic impact, and are clinically important emerging pathogens. Despite the impact of human norovirus-induced disease and the potential for emergence of highly virulent strains, the pathogenic features of infection are not well understood due to the lack of a cell culture system and previous lack of animal models. This review summarizes the current understanding of norovirus pathogenesis from the histological to the molecular level, including contributions from new model

  1. High pressure processing inactivates human norovirus within oysters

    USDA-ARS?s Scientific Manuscript database

    Consumption of raw bivalve mollusks can result in norovirus infection. One potential intervention for virus-contaminated shellfish is high pressure processing (HPP). Currently HPP is known to inactivate Vibrio bacteria, hepatitis A virus, and murine norovirus within oysters. To evaluate the potentia...

  2. Hydrogen Peroxide Vapor Decontamination in a Patient Room Using Feline Calicivirus and Murine Norovirus as Surrogate Markers for Human Norovirus.

    PubMed

    Holmdahl, Torsten; Walder, Mats; Uzcátegui, Nathalie; Odenholt, Inga; Lanbeck, Peter; Medstrand, Patrik; Widell, Anders

    2016-05-01

    To determine whether hydrogen peroxide vapor (HPV) could be used to decontaminate caliciviruses from surfaces in a patient room. Feline calicivirus (FCV) and murine norovirus (MNV) were used as surrogate viability markers to mimic the noncultivable human norovirus. Cell culture supernatants of FCV and MNV were dried in triplicate 35-mm wells of 6-well plastic plates. These plates were placed in various positions in a nonoccupied patient room that was subsequently exposed to HPV. Control plates were positioned in a similar room but were never exposed to HPV. Virucidal activity was measured in cell culture by reduction in 50% tissue culture infective dose titer for FCV and by both 50% tissue culture infective dose titer and plaque reduction for MNV. Neither viable FCV nor viable MNV could be detected in the test room after HPV treatment. At least 3.65 log reduction for FCV and at least 3.67 log reduction for MNV were found by 50% tissue culture infective dose. With plaque assay, measurable reduction for MNV was at least 2.85 log units. The successful inactivation of both surrogate viruses indicates that HPV could be a useful tool for surface decontamination of a patient room contaminated by norovirus. Hence nosocomial spread to subsequent patients can be avoided.

  3. Identifying human milk glycans that inhibit norovirus binding using surface plasmon resonance

    PubMed Central

    Shang, Jing; Piskarev, Vladimir E; Xia, Ming; Huang, Pengwei; Jiang, Xi; Likhosherstov, Leonid M; Novikova, Olga S; Newburg, David S; Ratner, Daniel M

    2013-01-01

    Human milk glycans inhibit binding between norovirus and its host glycan receptor; such competitive inhibition by human milk glycans is associated with a reduced risk of infection. The relationship between the presence of specific structural motifs in the human milk glycan and its ability to inhibit binding by specific norovirus strains requires facile, accurate and miniaturized-binding assays. Toward this end, a high-throughput biosensor platform was developed based on surface plasmon resonance imaging (SPRi) of glycan microarrays. The SPRi was validated, and its utility was tested, by measuring binding specificities between defined human milk glycan epitopes and the capsids of two common norovirus strains, VA387 and Norwalk. Human milk oligosaccharide (HMOS)-based neoglycoconjugates, including chemically derived neoglycoproteins and oligosaccharide-glycine derivatives, were used to represent polyvalent glycoconjugates and monovalent oligosaccharides, respectively, in human milk. SPRi binding results established that the glycan motifs that bind norovirus capsids depend upon strain; VA387 capsid interacts with two neoglycoproteins, whereas Norwalk capsid binds to a different set of HMOS motifs in the form of both polyvalent neoglycoproteins and monovalent oligosaccharides. SPRi competitive binding assays further demonstrated that specific norovirus-binding glycans are able to inhibit norovirus capsid binding to their host receptors. A polyvalent neoglycoconjugate with clustered carbohydrate moieties is required for the inhibition of VA387 capsid binding to host receptor glycans, whereas both monovalent oligosaccharides and polyvalent neoglycoconjugates are able to inhibit Norwalk capsid binding to its host receptor. Binding of HMOS and HMOS-based neoglycoconjugates to norovirus capsids depends upon the specific strain characteristics, implying that HMOS and their polyvalent derivatives are potential anti-adhesive agents for norovirus prophylaxis. PMID:24026239

  4. Identifying human milk glycans that inhibit norovirus binding using surface plasmon resonance.

    PubMed

    Shang, Jing; Piskarev, Vladimir E; Xia, Ming; Huang, Pengwei; Jiang, Xi; Likhosherstov, Leonid M; Novikova, Olga S; Newburg, David S; Ratner, Daniel M

    2013-12-01

    Human milk glycans inhibit binding between norovirus and its host glycan receptor; such competitive inhibition by human milk glycans is associated with a reduced risk of infection. The relationship between the presence of specific structural motifs in the human milk glycan and its ability to inhibit binding by specific norovirus strains requires facile, accurate and miniaturized-binding assays. Toward this end, a high-throughput biosensor platform was developed based on surface plasmon resonance imaging (SPRi) of glycan microarrays. The SPRi was validated, and its utility was tested, by measuring binding specificities between defined human milk glycan epitopes and the capsids of two common norovirus strains, VA387 and Norwalk. Human milk oligosaccharide (HMOS)-based neoglycoconjugates, including chemically derived neoglycoproteins and oligosaccharide-glycine derivatives, were used to represent polyvalent glycoconjugates and monovalent oligosaccharides, respectively, in human milk. SPRi binding results established that the glycan motifs that bind norovirus capsids depend upon strain; VA387 capsid interacts with two neoglycoproteins, whereas Norwalk capsid binds to a different set of HMOS motifs in the form of both polyvalent neoglycoproteins and monovalent oligosaccharides. SPRi competitive binding assays further demonstrated that specific norovirus-binding glycans are able to inhibit norovirus capsid binding to their host receptors. A polyvalent neoglycoconjugate with clustered carbohydrate moieties is required for the inhibition of VA387 capsid binding to host receptor glycans, whereas both monovalent oligosaccharides and polyvalent neoglycoconjugates are able to inhibit Norwalk capsid binding to its host receptor. Binding of HMOS and HMOS-based neoglycoconjugates to norovirus capsids depends upon the specific strain characteristics, implying that HMOS and their polyvalent derivatives are potential anti-adhesive agents for norovirus prophylaxis.

  5. Interactions between Human Norovirus Surrogates and Acanthamoeba spp.

    PubMed Central

    Hsueh, Tun-Yun

    2015-01-01

    Human noroviruses (HuNoVs) are the most common cause of food-borne disease outbreaks, as well as virus-related waterborne disease outbreaks in the United States. Here, we hypothesize that common free-living amoebae (FLA)—ubiquitous in the environment, known to interact with pathogens, and frequently isolated from water and fresh produce—could potentially act as reservoirs of HuNoV and facilitate the environmental transmission of HuNoVs. To investigate FLA as reservoirs for HuNoV, the interactions between two Acanthamoeba species, A. castellanii and A. polyphaga, as well as two HuNoV surrogates, murine norovirus type 1 (MNV-1) and feline calicivirus (FCV), were evaluated. The results showed that after 1 h of amoeba-virus incubation at 25°C, 490 and 337 PFU of MNV-1/ml were recovered from A. castellanii and A. polyphaga, respectively, while only few or no FCVs were detected. In addition, prolonged interaction of MNV-1 with amoebae was investigated for a period of 8 days, and MNV-1 was demonstrated to remain stable at around 200 PFU/ml from day 2 to day 8 after virus inoculation in A. castellanii. Moreover, after a complete amoeba life cycle (i.e., encystment and excystment), infectious viruses could still be detected. To determine the location of virus associated with amoebae, immunofluorescence experiments were performed and showed MNV-1 transitioning from the amoeba surface to inside the amoeba over a 24-h period. These results are significant to the understanding of how HuNoVs may interact with other microorganisms in the environment in order to aid in its persistence and survival, as well as potential transmission in water and to vulnerable food products such as fresh produce. PMID:25841006

  6. Replication of human noroviruses in stem cell-derived human enteroids

    USDA-ARS?s Scientific Manuscript database

    The major barrier to research and development of effective interventions for human noroviruses (HuNoVs) has been the lack of a robust and reproducible in vitro cultivation system. HuNoVs are the leading cause of gastroenteritis worldwide. We report successful cultivation of multiple HuNoV strains in...

  7. Distribution of Human Norovirus in the Coastal Waters of South Korea

    PubMed Central

    Choi, Yong Seon; Kim, Ji Young; Yoo, Chang Hoon; Yoon, Hyun Jin; Kim, Tae-Ok; Choi, Hyun Bae; Kim, Ji Hoon; Choi, Jong Deok; Park, Kwon-Sam; Shin, Yongsik; Kim, Young-Mog; Ko, GwangPyo; Jeong, Yong Seok

    2016-01-01

    The presence of human norovirus in the aquatic environment can cause outbreaks related to recreational activities and the consumption of norovirus-contaminated clams. In this study, we investigated the prevalence of norovirus genogroups I (GI) and II (GII) in the coastal aquatic environment in South Korea (March 2014 to February 2015). A total of 504 water samples were collected periodically from four coastal areas (total sites = 63), of which 44 sites were in estuaries (clam fisheries) and 19 were in inflow streams. RT-PCR analysis targeting ORF2 region C revealed that 20.6% of the water samples were contaminated by GI (13.3%) or GII (16.6%). The prevalence of human norovirus was higher in winter/spring than in summer/fall, and higher in inflow streams (50.0%) than in estuaries (7.9%). A total of 229 human norovirus sequences were identified from the water samples, and phylogenetic analysis showed that the sequences clustered into eight GI genotypes (GI.1, 2, 3, 4, 5, 6, 7, and 9) and nine GII genotypes (GII.2, 3, 4, 5, 6, 11, 13, 17, and 21). This study highlighted three issues: 1) a strong correlation between norovirus contamination via inflow streams and coastal areas used in clam fisheries; 2) increased prevalence of certain non-GII.4 genotypes, exceeding that of the GII.4 pandemic variants; 3) seasonal shifts in the dominant genotypes of both GI and GII. PMID:27681683

  8. Molecular evolution of the capsid gene in human norovirus genogroup II

    PubMed Central

    Kobayashi, Miho; Matsushima, Yuki; Motoya, Takumi; Sakon, Naomi; Shigemoto, Naoki; Okamoto-Nakagawa, Reiko; Nishimura, Koichi; Yamashita, Yasutaka; Kuroda, Makoto; Saruki, Nobuhiro; Ryo, Akihide; Saraya, Takeshi; Morita, Yukio; Shirabe, Komei; Ishikawa, Mariko; Takahashi, Tomoko; Shinomiya, Hiroto; Okabe, Nobuhiko; Nagasawa, Koo; Suzuki, Yoshiyuki; Katayama, Kazuhiko; Kimura, Hirokazu

    2016-01-01

    Capsid protein of norovirus genogroup II (GII) plays crucial roles in host infection. Although studies on capsid gene evolution have been conducted for a few genotypes of norovirus, the molecular evolution of norovirus GII is not well understood. Here we report the molecular evolution of all GII genotypes, using various bioinformatics techniques. The time-scaled phylogenetic tree showed that the present GII strains diverged from GIV around 1630CE at a high evolutionary rate (around 10−3 substitutions/site/year), resulting in three lineages. The GII capsid gene had large pairwise distances (maximum > 0.39). The effective population sizes of the present GII strains were large (>102) for about 400 years. Positive (20) and negative (over 450) selection sites were estimated. Moreover, some linear and conformational B-cell epitopes were found in the deduced GII capsid protein. These results suggested that norovirus GII strains rapidly evolved with high divergence and adaptation to humans. PMID:27384324

  9. Norovirus-host interaction: multi-selections by human HBGAs

    PubMed Central

    Tan, Ming; Jiang, Xi

    2011-01-01

    The discovery of human histo-blood group antigens (HBGAs) as receptors or ligands of noroviruses (NoVs) raises a question about the potential role of host factors in the evolution and diversity of NoVs. Recent structural analysis of selected strains in the two major genogroups of human NoVs (GI and GII) demonstrated highly conserved HBGA binding interfaces within the two groups but not between them, indicating convergent evolution of GI and GII NoVs. GI and GII NoVs are likely introduced to humans from different non-human hosts with the HBGAs as a common niche. Each genogroup has further diverged into multiple sub-lineages (genotypes) through selections by the polymorphic HBGAs of the hosts. An elucidation of such pathogen-host interaction, including determination of the phenotypes of NoV-HBGAs interaction for each genotype, is important in understanding the epidemiology, classification and disease control and prevention of NoVs. A model of this multi-selection of NoVs by HBGAs is proposed. PMID:21705222

  10. Quantification of Human Norovirus GII on Hands of Mothers with Children Under the Age of Five Years in Bagamoyo, Tanzania.

    PubMed

    Mattioli, Mia Catharine M; Davis, Jennifer; Mrisho, Mwifadhi; Boehm, Alexandria B

    2015-09-01

    Human noroviruses are the most common cause of viral gastroenteritis worldwide and one of the leading causes of viral diarrhea in children under the age of 5 years. Hands have been shown to play an important role in norovirus transmission. Norovirus outbreaks tend to exhibit strong seasonality, most often occurring during cold, dry months, but recently have also been documented during hot, dry winter months in the southern hemisphere. Other research suggests that rainfall is an important factor in norovirus outbreaks. This study examines the prevalence and concentration of human norovirus GII on the hands of mothers in Bagamoyo, Tanzania, during the rainy and dry seasons. Norovirus GII was detected in approximately 5% of hand rinse samples during both the rainy and dry seasons. Fecal indicator bacteria levels, Escherichia coli and enterococci, in hand rinse samples were not associated with norovirus hand contamination. Turbidity of the hand rinses was found to be associated with norovirus presence on mothers' hands; however, this relationship was only observed during the rainy season. The results suggest mothers' hands serve as a source of norovirus exposure for young children in Tanzanian households, and further work is needed to determine better indicators of norovirus contamination in these environments.

  11. Quantification of Human Norovirus GII on Hands of Mothers with Children under the Age of Five Years in Bagamoyo, Tanzania

    PubMed Central

    Mattioli, Mia Catharine M.; Davis, Jennifer; Mrisho, Mwifadhi; Boehm, Alexandria B.

    2015-01-01

    Human noroviruses are the most common cause of viral gastroenteritis worldwide and one of the leading causes of viral diarrhea in children under the age of 5 years. Hands have been shown to play an important role in norovirus transmission. Norovirus outbreaks tend to exhibit strong seasonality, most often occurring during cold, dry months, but recently have also been documented during hot, dry winter months in the southern hemisphere. Other research suggests that rainfall is an important factor in norovirus outbreaks. This study examines the prevalence and concentration of human norovirus GII on the hands of mothers in Bagamoyo, Tanzania, during the rainy and dry seasons. Norovirus GII was detected in approximately 5% of hand rinse samples during both the rainy and dry seasons. Fecal indicator bacteria levels, Escherichia coli and enterococci, in hand rinse samples were not associated with norovirus hand contamination. Turbidity of the hand rinses was found to be associated with norovirus presence on mothers' hands; however, this relationship was only observed during the rainy season. The results suggest mothers' hands serve as a source of norovirus exposure for young children in Tanzanian households, and further work is needed to determine better indicators of norovirus contamination in these environments. PMID:26149861

  12. Defining cell culture conditions to improve human norovirus infectivity assays.

    PubMed

    Straub, T M; Hutchison, J R; Bartholomew, R A; Valdez, C O; Valentine, N B; Dohnalkova, A; Ozanich, R M; Bruckner-Lea, C J

    2013-01-01

    Significant difficulties remain for determining whether human noroviruses (hNoV) recovered from water, food, and environmental samples are infectious. Three-dimensional (3-D) tissue culture of human intestinal cells has shown promise in developing an infectivity assay, but reproducibility, even within a single laboratory, remains problematic. From the literature and our observations, we hypothesized that the common factors that lead to more reproducible hNoV infectivity in vitro requires that the cell line be (1) of human gastrointestinal origin, (2) expresses apical microvilli, and (3) be a positive secretor cell line. The C2BBe1 cell line, which is a brush-border producing clone of Caco-2, meets these three criteria. When challenged with Genogroup II viruses, we observed a 2 Log(10) increase in viral RNA titer. A passage experiment with GII viruses showed evidence of the ability to propagate hNoV by both quantitative reverse transcription polymerase chain reaction (qRT-PCR) and microscopy. In our hands, using 3-D C2BBe1 cells improves reproducibility of the infectivity assay for hNoV, but the assay can still be variable. Two sources of variability include the cells themselves (mixed phenotypes of small and large intestine) and initial titer measurements using qRT-PCR that measures all RNA vs. plaque assays that measure infectious virus.

  13. Defining cell culture conditions to improve human norovirus infectivity assays

    SciTech Connect

    Straub, Tim M.; Hutchison, Janine R.; Bartholomew, Rachel A.; Valdez, Catherine O.; Valentine, Nancy B.; Dohnalkova, Alice; Ozanich, Richard M.; Bruckner-Lea, Cindy J.

    2013-01-10

    Significant difficulties remain for determining whether human noroviruses (hNoV) recovered from water, food, and environmental samples are infectious. Three-dimensional tissue culture of human intestinal cells has shown promise in developing an infectivity assay, but reproducibility, even within a single laboratory, remains problematic. From the literature and our observations, we hypothesized that the common factors that leads to more reproducible hNoV infectivity in vitro requires that the cell line be 1) of human gastrointestinal origin, 2) expresses apical microvilli, and 3) be a positive secretor cell line. The C2BBe1 cell line, which is a brush-border producing clone of Caco-2, meets these three criteria. When challenged with Genogroup II viruses, we observed a 2 Log10 increase in viral RNA titer. A passage experiment with GII viruses showed evidence of the ability to propagate hNoV by both reverse transcription quantitative PCR (qRT-PCR) and microscopy. Using 3-D C2BBe1 cells improves reproducibility of the infectivity assay for hNoV, but the assay can still be variable. Two sources of variability include the cells themselves (mixed phenotypes of small and large intestine) and initial titer measurements using quantitative reverse transcription PCR (qRT-PCR) that measures all RNA vs. plaque assays that measure infectious virus.

  14. High pressure inactivation of human norovirus virus-like particles: evidence that the capsid of human norovirus is highly pressure resistant

    USDA-ARS?s Scientific Manuscript database

    Human norovirus (NoV) is the leading cause of non-bacterial acute gastroenteritis epidemics worldwide. High pressure processing (HPP) has been considered a promising non-thermal processing technology to inactivate food- and water-borne viral pathogens. Due to the lack of an effective cell culture fo...

  15. Identification of immune and viral correlates of norovirus protective immunity through comparative study of intra-cluster norovirus strains.

    PubMed

    Zhu, Shu; Regev, Doron; Watanabe, Makiko; Hickman, Danielle; Moussatche, Nissin; Jesus, Desyree Murta; Kahan, Shannon M; Napthine, Sawsan; Brierley, Ian; Hunter, Robert N; Devabhaktuni, Divya; Jones, Melissa K; Karst, Stephanie M

    2013-01-01

    Whether or not primary norovirus infections induce protective immunity has become a controversial issue, potentially confounded by the comparison of data from genetically distinct norovirus strains. Early human volunteer studies performed with a norovirus-positive inoculum initially led to the conclusion that primary infection does not generate long-term, protective immunity. More recently though, the epidemiological pattern of norovirus pandemics has led to the extrapolation that primary norovirus infection induces herd immunity. While these are seemingly discordant observations, they may in fact reflect virus strain-, cluster-, or genogroup-specific differences in protective immunity induction. Here, we report that highly genetically related intra-cluster murine norovirus strains differ dramatically in their ability to induce a protective immune response: Primary MNV-3 infection induced robust and cross-reactive protection, whereas primary MNV-1 infection induced modest homotypic and no heterotypic protection. In addition to this fundamental observation that intra-cluster norovirus strains display remarkable differences in protective immunity induction, we report three additional important observations relevant to norovirus:host interactions. First, antibody and CD4⁺ T cells are essential to controlling secondary norovirus infections. Second, the viral minor structural protein VP2 regulates the maturation of antigen presenting cells and protective immunity induction in a virus strain-specific manner, pointing to a mechanism by which MNV-1 may prevent the stimulation of memory immune responses. Third, VF1-mediated regulation of cytokine induction also correlates with protective immunity induction. Thus, two highly genetically-related norovirus strains displayed striking differences in induction of protective immune responses, strongly suggesting that the interpretation of norovirus immunity and vaccine studies must consider potential virus strain

  16. Challenges of Culturing Human Norovirus in Three-Dimensional Organoid Intestinal Cell Culture Models

    PubMed Central

    Papafragkou, Efstathia; Hewitt, Joanne; Park, Geun Woo; Greening, Gail; Vinjé, Jan

    2013-01-01

    Human noroviruses are the most common cause of acute gastroenteritis worldwide. Recently, cell culture systems have been described using either human embryonic intestinal epithelial cells (Int-407) or human epithelial colorectal adenocarcinoma cells (Caco-2) growing on collagen-I porous micro carrier beads in a rotating bioreactor under conditions of physiological fluid shear. Here, we describe the efforts from two independent laboratories to implement this three dimensional (3D) cell culture system for the replication of norovirus. Int-407 and Caco-2 were grown in a rotating bioreactor for up to 28 days. Prior to infection, cells were screened for the presence of microvilli by electron microscopy and stained for junction proteins (zonula occludens-1, claudin-1, and β-catenin). Differentiated 3D cells were transferred to 24-well plates and infected with bacteria-free filtrates of various norovirus genotypes (GI.1, GI.3, GI.8, GII.2, GII.4, GII.7, and GII.8). At 12 h, 24 h, and 48 h post inoculation, viral RNA from both cells and supernatants were collected and analyzed for norovirus RNA by real-time reverse transcription PCR. Despite observations of high expression of junction proteins and microvilli development in stained thin sections, our data suggest no significant increase in viral titer based on norovirus RNA copy number during the first 48 h after inoculation for the different samples and virus culture conditions tested. Our combined efforts demonstrate that 3D cell culture models using Int-407 or Caco-2 cells do not support norovirus replication and highlight the complexity and difficulty of developing a reproducible in vitro cell culture system for human norovirus. PMID:23755105

  17. Challenges of culturing human norovirus in three-dimensional organoid intestinal cell culture models.

    PubMed

    Papafragkou, Efstathia; Hewitt, Joanne; Park, Geun Woo; Greening, Gail; Vinjé, Jan

    2014-01-01

    Human noroviruses are the most common cause of acute gastroenteritis worldwide. Recently, cell culture systems have been described using either human embryonic intestinal epithelial cells (Int-407) or human epithelial colorectal adenocarcinoma cells (Caco-2) growing on collagen-I porous micro carrier beads in a rotating bioreactor under conditions of physiological fluid shear. Here, we describe the efforts from two independent laboratories to implement this three dimensional (3D) cell culture system for the replication of norovirus. Int-407 and Caco-2 were grown in a rotating bioreactor for up to 28 days. Prior to infection, cells were screened for the presence of microvilli by electron microscopy and stained for junction proteins (zonula occludens-1, claudin-1, and β-catenin). Differentiated 3D cells were transferred to 24-well plates and infected with bacteria-free filtrates of various norovirus genotypes (GI.1, GI.3, GI.8, GII.2, GII.4, GII.7, and GII.8). At 12 h, 24 h, and 48 h post inoculation, viral RNA from both cells and supernatants were collected and analyzed for norovirus RNA by real-time reverse transcription PCR. Despite observations of high expression of junction proteins and microvilli development in stained thin sections, our data suggest no significant increase in viral titer based on norovirus RNA copy number during the first 48 h after inoculation for the different samples and virus culture conditions tested. Our combined efforts demonstrate that 3D cell culture models using Int-407 or Caco-2 cells do not support norovirus replication and highlight the complexity and difficulty of developing a reproducible in vitro cell culture system for human norovirus.

  18. Environmental Transmission of Human Noroviruses in Shellfish Waters

    PubMed Central

    Lees, David N.

    2014-01-01

    Human noroviruses (NoV) are the most common cause of epidemic gastroenteritis following consumption of bivalve shellfish contaminated with fecal matter. NoV levels can be effectively reduced by some sewage treatment processes such as activated sludge and membrane bioreactors. However, tertiary sewage treatment and substantial sewage dilution are usually required to achieve low concentrations of virus in shellfish. Most outbreaks have been associated with shellfish harvested from waters affected by untreated sewage from, for example, storm overflows or overboard disposal of feces from boats. In coastal waters, NoV can remain in suspension or associate with organic and inorganic matter and be accumulated by shellfish. Shellfish take considerably longer to purge NoV than fecal indicator bacteria when transferred from sewage-polluted estuarine waters to uncontaminated waters. The abundance and distribution of NoV in shellfish waters are influenced by the levels of sewage treatment, proximity of shellfish beds to sewage sources, rainfall, river flows, salinity, and water temperature. Detailed site-specific information on these factors is required to design measures to control the viral risk. PMID:24705321

  19. Enterobacter cloacae inhibits human norovirus infectivity in gnotobiotic pigs.

    PubMed

    Lei, Shaohua; Samuel, Helen; Twitchell, Erica; Bui, Tammy; Ramesh, Ashwin; Wen, Ke; Weiss, Mariah; Li, Guohua; Yang, Xingdong; Jiang, Xi; Yuan, Lijuan

    2016-04-26

    Human noroviruses (HuNoVs) are the leading cause of epidemic gastroenteritis worldwide. Study of HuNoV biology has been hampered by the lack of an efficient cell culture system. Recently, enteric commensal bacteria Enterobacter cloacae has been recognized as a helper in HuNoV infection of B cells in vitro. To test the influences of E. cloacae on HuNoV infectivity and to determine whether HuNoV infects B cells in vivo, we colonized gnotobiotic pigs with E. cloacae and inoculated pigs with 2.74 × 10(4) genome copies of HuNoV. Compared to control pigs, reduced HuNoV shedding was observed in E. cloacae colonized pigs, characterized by significantly shorter duration of shedding in post-inoculation day 10 subgroup and lower cumulative shedding and peak shedding in individual pigs. Colonization of E. cloacae also reduced HuNoV titers in intestinal tissues and in blood. In both control and E. cloacae colonized pigs, HuNoV infection of enterocytes was confirmed, however infection of B cells was not observed in ileum, and the entire lamina propria in sections of duodenum, jejunum, and ileum were HuNoV-negative. In summary, E. cloacae inhibited HuNoV infectivity, and B cells were not a target cell type for HuNoV in gnotobiotic pigs, with or without E. cloacae colonization.

  20. Enterobacter cloacae inhibits human norovirus infectivity in gnotobiotic pigs

    PubMed Central

    Lei, Shaohua; Samuel, Helen; Twitchell, Erica; Bui, Tammy; Ramesh, Ashwin; Wen, Ke; Weiss, Mariah; Li, Guohua; Yang, Xingdong; Jiang, Xi; Yuan, Lijuan

    2016-01-01

    Human noroviruses (HuNoVs) are the leading cause of epidemic gastroenteritis worldwide. Study of HuNoV biology has been hampered by the lack of an efficient cell culture system. Recently, enteric commensal bacteria Enterobacter cloacae has been recognized as a helper in HuNoV infection of B cells in vitro. To test the influences of E. cloacae on HuNoV infectivity and to determine whether HuNoV infects B cells in vivo, we colonized gnotobiotic pigs with E. cloacae and inoculated pigs with 2.74 × 104 genome copies of HuNoV. Compared to control pigs, reduced HuNoV shedding was observed in E. cloacae colonized pigs, characterized by significantly shorter duration of shedding in post-inoculation day 10 subgroup and lower cumulative shedding and peak shedding in individual pigs. Colonization of E. cloacae also reduced HuNoV titers in intestinal tissues and in blood. In both control and E. cloacae colonized pigs, HuNoV infection of enterocytes was confirmed, however infection of B cells was not observed in ileum, and the entire lamina propria in sections of duodenum, jejunum, and ileum were HuNoV-negative. In summary, E. cloacae inhibited HuNoV infectivity, and B cells were not a target cell type for HuNoV in gnotobiotic pigs, with or without E. cloacae colonization. PMID:27113278

  1. High pressure treatment of human norovirus virus-like particles: factors affecting destruction efficacy

    USDA-ARS?s Scientific Manuscript database

    Human norovirus (NoV) accounts for more than 90% of nonbacterial gastroenteritis. To date, the efficacy of human NoV inactivation interventions cannot be accurately evaluated because the virus is nonculturable. In this study, we aimed to estimate inactivation of human NoV by high pressure processing...

  2. Identification of human single-chain antibodies with broad reactivity for noroviruses

    PubMed Central

    Huang, Wanzhi; Samanta, Moumita; Crawford, Sue E.; Estes, Mary K.; Neill, Frederick H.; Atmar, Robert L.; Palzkill, Timothy

    2014-01-01

    Norovirus infections are a common cause of gastroenteritis and new methods to rapidly diagnose norovirus infections are needed. The goal of this study was to identify antibodies that have broad reactivity of binding to various genogroups of norovirus. A human scFv phage display library was used to identify two antibodies, HJT-R3-A9 and HJT-R3-F7, which bind to both genogroups I and II norovirus virus-like particles (VLPs). Mapping experiments indicated that the HJT-R3-A9 clone binds to the S-domain while the HJT-R3-F7 clone binds the P-domain of the VP1 capsid protein. In addition, a family of scFv antibodies was identified by elution of phage libraries from the GII.4 VLP target using a carbohydrate that serves as an attachment factor for norovirus on human cells. These antibodies were also found to recognize both GI and GII VLPs in enzyme-linked immunosorbent assay (ELISA) experiments. The HJT-R3-A9, HJT-R3-F7 and scFv antibodies identified with carbohydrate elution were shown to detect antigen from a clinical sample known to contain GII.4 norovirus but not a negative control sample. Finally, phages displaying the HJT-R3-A9 scFv can be used directly to detect both GI.1 and GII.4 norovirus from stool samples, which has the potential to simplify and reduce the cost of diagnostics based on antibody-based ELISA methods. PMID:24946948

  3. Genetic mapping of a highly variable norovirus GII.4 blockade epitope: potential role in escape from human herd immunity.

    PubMed

    Debbink, Kari; Donaldson, Eric F; Lindesmith, Lisa C; Baric, Ralph S

    2012-01-01

    Noroviruses account for 96% of viral gastroenteritis cases worldwide, with GII.4 strains responsible >80% of norovirus outbreaks. Histo-blood group antigens (HBGAs) are norovirus binding ligands, and antigenic and preferential HBGA binding profiles vary over time as new GII.4 strains emerge. The capsid P2 subdomain facilitates HBGA binding, contains neutralizing antibody epitopes, and likely evolves in response to herd immunity. To identify amino acids regulating HBGA binding and antigenic differences over time, we created chimeric virus-like particles (VLPs) between the GII.4-1987 and GII.4-2006 strains by exchanging amino acids in putative epitopes and characterized their antigenic and HBGA binding profiles using anti-GII.4-1987 and -2006 mouse monoclonal antibodies (MAbs) and polyclonal sera, 1988 outbreak human sera, and synthetic HBGAs. The exchange of amino acids 393 to 395 between GII.4-1987 and GII.4-2006 resulted in altered synthetic HBGA binding compared to parental strains. Introduction of GII.4-1987 residues 294, 297 to 298, 368, and 372 (epitope A) into GII.4-2006 resulted in reactivity with three anti-GII.4-1987 MAbs and reduced reactivity with four anti-GII.4-2006 MAbs. The three anti-GII.4-1987 MAbs also blocked chimeric VLP-HBGA interaction, while an anti-GII.4-2006 blocking antibody did not, indicating that epitope A amino acids comprise a potential neutralizing epitope for GII.4-1987 and GII.4-2006. We also tested GII.4-1987-immunized mouse polyclonal sera and 1988 outbreak human sera for the ability to block chimeric VLP-HBGA interaction and found that epitope A amino acids contribute significantly to the GII.4-1987 blockade response. Our data provide insights that help explain the emergence of new GII.4 epidemic strains over time, may aid development of norovirus therapeutics, and may help predict the emergence of future epidemic strains.

  4. Recovery and Disinfection of Two Human Norovirus Surrogates, Feline Calicivirus and Murine Norovirus, from Hard Nonporous and Soft Porous Surfaces.

    PubMed

    Yeargin, Thomas; Fraser, Angela; Huang, Guohui; Jiang, Xiuping

    2015-10-01

    Human norovirus is a leading cause of foodborne disease and can be transmitted through many routes, including environmental exposure to fomites. In this study, both the recovery and inactivation of two human norovirus surrogates, feline calicivirus (FCV) and murine norovirus (MNV), on hard nonporous surfaces (glass) and soft porous surfaces (polyester and cotton) were evaluated by both plaque assay and reverse transcription quantitative PCR method. Two disinfectants, sodium hypochlorite (8.25%) and accelerated hydrogen peroxide (AHP, at 4.25%) were evaluated for disinfection efficacy. Five coupons per surface type were used to evaluate the recovery of FCV and MNV by sonication and stomaching and the disinfection of each surface type by using 5 ml of disinfectant for a contact time of 5 min. FCV at an initial titer of ca. 7 log PFU/ml was recovered from glass, cotton, and polyester at 6.2, 5.4, and 3.8 log PFU/ml, respectively, compared with 5.5, 5.2, and 4.1 log PFU/ml, respectively, for MNV with an initial titer of ca. 6 log PFU/ml. The use of sodium hypochlorite (5,000 ppm) was able to inactivate both FCV and MNV (3.1 to 5.5 log PFU/ml) below the limit of detection on all three surface types. AHP (2,656 ppm) inactivated FCV (3.1 to 5.5 log PFU/ml) below the limit of detection for all three surface types but achieved minimal inactivation of MNV (0.17 to 1.37 log PFU/ml). Reduction of viral RNA by sodium hypochlorite corresponded to 2.72 to 4.06 log reduction for FCV and 2.07 to 3.04 log reduction for MNV on all three surface types. Reduction of viral RNA by AHP corresponded to 1.89 to 3.4 log reduction for FCV and 0.54 to 0.85 log reduction for MNV. Our results clearly indicate that both virus and surface types significantly influence recovery efficiency and disinfection efficacy. Based on the performance of our proposed testing method, an improvement in virus recovery will be needed to effectively validate virus disinfection of soft porous surfaces.

  5. A Homozygous Nonsense Mutation (428G→A) in the Human Secretor (FUT2) Gene Provides Resistance to Symptomatic Norovirus (GGII) Infections

    PubMed Central

    Thorven, Maria; Grahn, Ammi; Hedlund, Kjell-Olof; Johansson, Hugo; Wahlfrid, Christer; Larson, Göran; Svensson, Lennart

    2005-01-01

    Noroviruses (formerly Norwalk-like viruses) are a major cause of acute gastroenteritis worldwide and are associated with a significant number of nosocomial and food-borne outbreaks. In this study we show that the human secretor FUT2 gene, which codes for an α(1,2)-fucosyltransferase synthesizing the H-type 1 antigen in saliva and mucosa, is associated with susceptibility to norovirus infections. Allelic polymorphism characterization at nucleotide 428 for symptomatic (n = 53) and asymptomatic (n = 62) individuals associated with nosocomial and sporadic norovirus outbreaks revealed that homozygous nonsense mutation (428G→A) in FUT2 segregated with complete resistance for the disease. Of all symptomatic individuals, 49% were homozygous (SeSe) and 51% heterozygous (Sese428) secretors, and none were secretor negative (se428se428), in contrast to 20% nonsecretors (se428se428) among Swedish blood donors (n = 104) (P < 0.0002) and 29% for asymptomatic individuals associated with nosocomial outbreaks (P < 0.00001). Furthermore, saliva from secretor-positive and symptomatic patients but not from secretor-negative and asymptomatic individuals bound the norovirus strain responsible for that particular outbreak. This is the first report showing that the FUT2 nonsecretor (se428se428) genotype is associated with resistance to nosocomial and sporadic outbreaks with norovirus. PMID:16306606

  6. Virucidal Efficacy of a Hydrogen Peroxide Nebulization Against Murine Norovirus and Feline Calicivirus, Two Surrogates of Human Norovirus.

    PubMed

    Zonta, William; Mauroy, Axel; Farnir, Frederic; Thiry, Etienne

    2016-12-01

    Human noroviruses (HuNoV) are amongst the leading causes of acute non-bacterial gastroenteritis in humans and can be transmitted via person-to-person contact, via contact with contaminated surfaces or by consumption of contaminated food. Contaminated surfaces in healthcare settings contribute to the transmission of viruses. No-touch automated room disinfection systems might prevent such a spread of contamination and thus their virucidal effect needs to be evaluated. The aim of this study was to assess the efficacy of a nebulization system spraying hydrogen peroxide on two main surrogates of HuNoV, namely murine norovirus (MNV) and feline calicivirus (FCV). The viruses were dried on cover glasses and on stainless steel discs and exposed to nebulization. The number of infectious viral particles and genomic copies before and after the nebulization was compared. The efficacy in reducing infectivity of both surrogates was demonstrated. For the infectious viral titre of MNV and FCV, a log10 reduction factor ≥4.84 and 4.85 was observed after nebulization, respectively, for tests on cover glasses and ≥3.90 and 5.30, respectively, for tests on stainless steel discs. Only low reductions in genomic copy numbers were observed for both surrogates. The nebulization of hydrogen peroxide showed a clear virucidal effect on both HuNoV surrogates, MNV and FCV, on two different carriers and the use of nebulization should be promoted in complementarity with conventional disinfection methods in healthcare settings and food processing facilities to reduce viral load and spread of contamination.

  7. Evaluation of a New Environmental Sampling Protocol for Detection of Human Norovirus on Inanimate Surfaces

    PubMed Central

    Lee, David; Treffiletti, Aimee; Hrsak, Mario; Shugart, Jill; Vinjé, Jan

    2015-01-01

    Inanimate surfaces are regarded as key vehicles for the spread of human norovirus during outbreaks. ISO method 15216 involves the use of cotton swabs for environmental sampling from food surfaces and fomites for the detection of norovirus genogroup I (GI) and GII. We evaluated the effects of the virus drying time (1, 8, 24, or 48 h), swab material (cotton, polyester, rayon, macrofoam, or an antistatic wipe), surface (stainless steel or a toilet seat), and area of the swabbed surface (25.8 cm2 to 645.0 cm2) on the recovery of human norovirus. Macrofoam swabs produced the highest rate of recovery of norovirus from surfaces as large as 645 cm2. The rates of recovery ranged from 2.2 to 36.0% for virus seeded on stainless-steel coupons (645.0 cm2) to 1.2 to 33.6% for toilet seat surfaces (700 cm2), with detection limits of 3.5 log10 and 4.0 log10 RNA copies. We used macrofoam swabs to collect environmental samples from several case cabins and common areas of a cruise ship where passengers had reported viral gastroenteritis symptoms. Seventeen (18.5%) of 92 samples tested positive for norovirus GII, and 4 samples could be sequenced and had identical GII.1 sequences. The viral loads of the swab samples from the cabins of the sick passengers ranged from 80 to 31,217 RNA copies, compared with 16 to 113 RNA copies for swab samples from public spaces. In conclusion, our swab protocol for norovirus may be a useful tool for outbreak investigations when no clinical samples are available to confirm the etiology. PMID:26116675

  8. Evaluation of a New Environmental Sampling Protocol for Detection of Human Norovirus on Inanimate Surfaces.

    PubMed

    Park, Geun Woo; Lee, David; Treffiletti, Aimee; Hrsak, Mario; Shugart, Jill; Vinjé, Jan

    2015-09-01

    Inanimate surfaces are regarded as key vehicles for the spread of human norovirus during outbreaks. ISO method 15216 involves the use of cotton swabs for environmental sampling from food surfaces and fomites for the detection of norovirus genogroup I (GI) and GII. We evaluated the effects of the virus drying time (1, 8, 24, or 48 h), swab material (cotton, polyester, rayon, macrofoam, or an antistatic wipe), surface (stainless steel or a toilet seat), and area of the swabbed surface (25.8 cm(2) to 645.0 cm(2)) on the recovery of human norovirus. Macrofoam swabs produced the highest rate of recovery of norovirus from surfaces as large as 645 cm(2). The rates of recovery ranged from 2.2 to 36.0% for virus seeded on stainless-steel coupons (645.0 cm(2)) to 1.2 to 33.6% for toilet seat surfaces (700 cm(2)), with detection limits of 3.5 log10 and 4.0 log10 RNA copies. We used macrofoam swabs to collect environmental samples from several case cabins and common areas of a cruise ship where passengers had reported viral gastroenteritis symptoms. Seventeen (18.5%) of 92 samples tested positive for norovirus GII, and 4 samples could be sequenced and had identical GII.1 sequences. The viral loads of the swab samples from the cabins of the sick passengers ranged from 80 to 31,217 RNA copies, compared with 16 to 113 RNA copies for swab samples from public spaces. In conclusion, our swab protocol for norovirus may be a useful tool for outbreak investigations when no clinical samples are available to confirm the etiology. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Simultaneous comparison of murine norovirus, feline calicivirus, coliphage MS2, and GII.4 norovirus to evaluate the efficacy of sodium hypochlorite against human norovirus on a fecally soiled stainless steel surface.

    PubMed

    Park, Geun Woo; Sobsey, Mark D

    2011-09-01

    Free chlorine as hypochlorite is recommended to decontaminate fecally contaminated surfaces to control human norovirus (NoV). We evaluated the efficacy of sodium hypochlorite to decontaminate GII.4 NoV and three surrogates of human NoVs, feline calicivirus (FCV), murine norovirus (MNV), and coliphage MS2, on a fecally soiled stainless steel surface. Reduction of infectivity of FCV, MNV, and MS2 was measured by plaque assay and the decline of genomic copy numbers of GII.4 NoV by reverse transcriptase-polymerase chain reaction. Sodium hypochlorite solution at 5000 ppm could inactivate FCV by 3 log(10) plaque forming units after approximately 1.9 minutes of contact time, but required longer exposure times of 3.2 and 4.5 minutes to reduce MNV and MS2 by 3 log(10), respectively. However, detection of viral RNA by reverse transcriptase-polymerase chain reaction assay may not be reliable to estimate the effectiveness of sodium hypochlorite against human NoV. Of three NoV surrogates, FCV is not the most resistant of the virus tested for inactivation by hypochlorite and thus is not the worst-case model for estimating NoV inactivation. Although the use of 5000 ppm of hypochlorite for fecally soiled surfaces is effective, it may require longer exposure times of ≥3 minutes to control NoVs. Surface precleaning before hypochlorite disinfection is recommended to initially reduce the fecal organic load for better virus inactivation and should be a part of the environmental hygiene response measures during an NoV outbreak or where NoV fecal contamination of environmental surfaces is likely or suspected to be present.

  10. The Effect of Malnutrition on Norovirus Infection

    PubMed Central

    Hickman, Danielle; Jones, Melissa K.; Zhu, Shu; Kirkpatrick, Ericka; Ostrov, David A.; Wang, Xiaoyu; Ukhanova, Maria; Sun, Yijun; Mai, Volker; Salemi, Marco; Karst, Stephanie M.

    2014-01-01

    ABSTRACT Human noroviruses are the primary cause of severe childhood diarrhea in the United States, and they are of particular clinical importance in pediatric populations in the developing world. A major contributing factor to the general increased severity of infectious diseases in these regions is malnutrition—nutritional status shapes host immune responses and the composition of the host intestinal microbiota, both of which can influence the outcome of pathogenic infections. In terms of enteric norovirus infections, mucosal immunity and intestinal microbes are likely to contribute to the infection outcome in substantial ways. We probed these interactions using a murine model of malnutrition and murine norovirus infection. Our results reveal that malnutrition is associated with more severe norovirus infections as defined by weight loss, impaired control of norovirus infections, reduced antiviral antibody responses, loss of protective immunity, and enhanced viral evolution. Moreover, the microbiota is dramatically altered by malnutrition. Interestingly, murine norovirus infection also causes changes in the host microbial composition within the intestine but only in healthy mice. In fact, the infection-associated microbiota resembles the malnutrition-associated microbiota. Collectively, these findings represent an extensive characterization of a new malnutrition model of norovirus infection that will ultimately facilitate elucidation of the nutritionally regulated host parameters that predispose to more severe infections and impaired memory immune responses. In a broad sense, this model may provide insight into the reduced efficacy of oral vaccines in malnourished hosts and the potential for malnourished individuals to act as reservoirs of emergent virus strains. PMID:24595373

  11. High pressure treatment of human norovirus-like particles: factors affecting destruction efficacy

    USDA-ARS?s Scientific Manuscript database

    Human norovirus (HuNoV) is the leading cause of foodborne diseases worldwide. High pressure processing (HPP) is considered a promising non-thermal technology to inactivate viral pathogens in foods. However, the effectiveness of HPP on inactivating HuNoV remains poorly understood because it cannot be...

  12. A Novel system for evaluating the interaction between human norovirus and receptors

    USDA-ARS?s Scientific Manuscript database

    Human noroviruses (HuNoVs) are major pathogens for acute nonbacterial gastroenteritis outbreaks. Many aspects of HuNoVs are poorly understood due to both the current inability to culture HuNoVs, and the lack of efficient small animal models. Recombinant HuNoV viral capsid proteins and/or P particles...

  13. Persistence and elimination of human norovirus in food and on food contact surfaces: a critical review

    USDA-ARS?s Scientific Manuscript database

    This critical review addresses the persistence of human norovirus (NoV) in water, shellfish, processed meats, soils and organic wastes; on berries, herbs, vegetables, fruits and salads; and on food contact surfaces. The review focuses on studies using NoV; information from studies involving only su...

  14. Alternative methods to determine infectivity of Tulane virus: a surrogate for human norovirus

    USDA-ARS?s Scientific Manuscript database

    Culturable animal caliciviruses are widely-used as surrogates for human norovirus (HuNoV), which can not replicate in cells. The infectivity of a culturable virus was traditionally determined by plaque assay and/or 50% tissue culture infectious dose (TCID50) assay, both of which are time-consuming ...

  15. Human norovirus inactivation in oysters by high hydrostatic pressure processing: A randomized double-blinded study

    USDA-ARS?s Scientific Manuscript database

    This randomized, double-blinded, clinical trial assessed the effect of high hydrostatic pressure processing (HPP) on genogroup I.1 human norovirus (HuNoV) inactivation in virus-seeded oysters when ingested by subjects. The safety and efficacy of HPP treatments were assessed in three study phases wi...

  16. Inactivation of human norovirus in contaminated oysters and clams by high-hydrostatic pressure

    USDA-ARS?s Scientific Manuscript database

    Human norovirus (NoV) is the most frequent causative agent of foodborne disease associated with shellfish consumption. In this study, the effect of high-hydrostatic pressure (HHP) on inactivation of NoV was determined. Genogroup I.1 (GI.1) or Genogroup II.4 (GII.4) NoV were inoculated into oyster ho...

  17. EVALUATION OF MURINE NOROVIRUS, FELINE CALICIVIRUS, POLIOVIRUS, AND MS2 AS SURROGATES FOR HUMAN NOROVIRUS IN a Model of Viral Persistence in SURFACE Water AND GROUNDWATER

    EPA Science Inventory

    Human noroviruses (NoV) are a significant cause of non bacterial gastroenteritis worldwide with contaminated drinking water a potential transmission route. The absence of a cell culture infectivity model for NoV necessitates the use of molecular methods and/or viral surrogate mod...

  18. EVALUATION OF MURINE NOROVIRUS, FELINE CALICIVIRUS, POLIOVIRUS, AND MS2 AS SURROGATES FOR HUMAN NOROVIRUS IN a Model of Viral Persistence in SURFACE Water AND GROUNDWATER

    EPA Science Inventory

    Human noroviruses (NoV) are a significant cause of non bacterial gastroenteritis worldwide with contaminated drinking water a potential transmission route. The absence of a cell culture infectivity model for NoV necessitates the use of molecular methods and/or viral surrogate mod...

  19. Comparison of Risk Predicted by Multiple Norovirus Dose-Response Models and Implications for Quantitative Microbial Risk Assessment.

    PubMed

    Van Abel, Nicole; Schoen, Mary E; Kissel, John C; Meschke, J Scott

    2016-06-10

    The application of quantitative microbial risk assessments (QMRAs) to understand and mitigate risks associated with norovirus is increasingly common as there is a high frequency of outbreaks worldwide. A key component of QMRA is the dose-response analysis, which is the mathematical characterization of the association between dose and outcome. For Norovirus, multiple dose-response models are available that assume either a disaggregated or an aggregated intake dose. This work reviewed the dose-response models currently used in QMRA, and compared predicted risks from waterborne exposures (recreational and drinking) using all available dose-response models. The results found that the majority of published QMRAs of norovirus use the 1 F1 hypergeometric dose-response model with α = 0.04, β = 0.055. This dose-response model predicted relatively high risk estimates compared to other dose-response models for doses in the range of 1-1,000 genomic equivalent copies. The difference in predicted risk among dose-response models was largest for small doses, which has implications for drinking water QMRAs where the concentration of norovirus is low. Based on the review, a set of best practices was proposed to encourage the careful consideration and reporting of important assumptions in the selection and use of dose-response models in QMRA of norovirus. Finally, in the absence of one best norovirus dose-response model, multiple models should be used to provide a range of predicted outcomes for probability of infection.

  20. Inactivation of Human Norovirus and Its Surrogates on Alfalfa Seeds by Aqueous Ozone.

    PubMed

    Wang, Qing; Markland, Sarah; Kniel, Kalmia E

    2015-08-01

    Alfalfa sprouts have been associated with numerous foodborne outbreaks. Previous studies investigated the effectiveness of aqueous ozone on bacterially contaminated seeds, yet little is known about the response of human norovirus (huNoV). This study assessed aqueous ozone for the disinfection of alfalfa seeds contaminated with huNoV and its surrogates. The inactivation of viruses without a food matrix was also investigated. Alfalfa seeds were inoculated with huNoV genogroup II, Tulane virus (TV), and murine norovirus (MNV); viruses alone or inoculated on seeds were treated in deionized water containing 6.25 ppm of aqueous ozone with agitation at 22°C for 0.5, 1, 5, 15, or 30 min. The data showed that aqueous ozone resulted in reductions of MNV and TV infectivity from 1.66 ± 1.11 to 5.60 ± 1.11 log PFU/g seeds; for all treatment times, significantly higher reductions were observed for MNV (P < 0.05). Viral genomes were relatively resistant, with a reduction of 1.50 ± 0.14 to 3.00 ± 0.14 log genomic copies/g seeds; the reduction of TV inoculated in water was similar to that of huNoV, whereas MNV had significantly greater reductions in genomic copies (P < 0.05). Similar trends were observed in ozone-treated viruses alone, with significantly higher levels of inactivation (P < 0.05), especially with reduced levels of infectivity for MNV and TV. The significant inactivation by aqueous ozone indicates that ozone may be a plausible substitute for chlorine as an alternative treatment for seeds. The behavior of TV was similar to that of huNoV, which makes it a promising surrogate for these types of scenarios.

  1. Replication of Human Noroviruses in Stem Cell-Derived Human Enteroids

    PubMed Central

    Ettayebi, Khalil; Crawford, Sue E.; Murakami, Kosuke; Broughman, James R.; Karandikar, Umesh; Tenge, Victoria R.; Neill, Frederick H.; Blutt, Sarah E.; Zeng, Xi-Lei; Qu, Lin; Kou, Baijun; Opekun, Antone R.; Burrin, Douglas; Graham, David Y.; Ramani, Sasirekha; Atmar, Robert L.

    2016-01-01

    The major barrier to research and development of effective interventions for human noroviruses (HuNoVs) has been the lack of a robust and reproducible in vitro cultivation system. HuNoVs are the leading cause of gastroenteritis worldwide. We report successful cultivation of multiple HuNoV strains in enterocytes in stem cell-derived, nontransformed human intestinal enteroid monolayer cultures. Bile, a critical factor of the intestinal milieu, is required for strain-dependent HuNoV replication. Lack of appropriate histoblood group antigen expression in intestinal cells restricts virus replication, and infectivity is abrogated by inactivation (e.g., irradiation, heating) and serum neutralization. This culture system recapitulates the human intestinal epithelium, permits human host-pathogen studies of previously noncultivatable pathogens, and allows the assessment of methods to prevent and treat HuNoV infections. PMID:27562956

  2. Identification of Cross-Reactive Norovirus CD4+ T Cell Epitopes ▿

    PubMed Central

    LoBue, Anna D.; Lindesmith, Lisa C.; Baric, Ralph S.

    2010-01-01

    Immune responses and the components of protective immunity following norovirus infection in humans are poorly understood. Although antibody responses following norovirus infection have been partially characterized, T cell responses in humans remain largely undefined. In contrast, T cells have been shown to be essential for viral clearance of mouse norovirus (MNV) infection. In this paper, we demonstrate that CD4+ T cells secrete gamma interferon (IFN-γ) in response to stimulation with MNV virus-like particles (VLPs) after MNV infection, supporting earlier reports for norovirus-infected mice and humans. Utilizing this model, we immunized mice with alphavirus vectors (Venezuelan equine encephalitis [VEE] virus replicon particles [VRPs]) expressing Norwalk virus (NV) or Farmington Hills virus (FH) virus-like particles to evaluate T cell epitopes shared between human norovirus strains. Stimulation of splenocytes from norovirus VRP-immunized mice with overlapping peptides from complete libraries of the NV or FH capsid proteins revealed specific amino acid sequences containing T cell epitopes that were conserved within genoclusters and genogroups. Immunization with heterologous norovirus VRPs resulted in specific cross-reactive IFN-γ secretion profiles following stimulation with NV and FH peptides in the mouse. Identification of unique strain-specific and cross-reactive epitopes may provide insight into homologous and heterologous T cell-mediated norovirus immunity and provide a platform for the study of norovirus-induced cellular immunity in humans. PMID:20573810

  3. Development of a Nanobody-Based Lateral Flow Immunoassay for Detection of Human Norovirus.

    PubMed

    Doerflinger, Sylvie Y; Tabatabai, Julia; Schnitzler, Paul; Farah, Carlo; Rameil, Steffen; Sander, Peter; Koromyslova, Anna; Hansman, Grant S

    2016-01-01

    Human noroviruses are the dominant cause of outbreaks of acute gastroenteritis. These viruses are usually detected by molecular methods, including reverse transcriptase PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Human noroviruses are genetically and antigenically diverse, with two main genogroups that are further subdivided into over 40 different genotypes. During the past decade, genogroup 2 genotype 4 (GII.4) has dominated in most countries, but recently, viruses belonging to GII.17 have increased in prevalence in a number of countries. A number of commercially available ELISAs and lateral flow immunoassays were found to have lower sensitivities to the GII.17 viruses, indicating that the antibodies used in these methods may not have a high level of cross-reactivity. In this study, we developed a rapid Nanobody-based lateral flow immunoassay (Nano-immunochromatography [Nano-IC]) for the detection of human norovirus in clinical specimens. The Nano-IC assay detected virions from two GII.4 norovirus clusters, which included the current dominant strain and a novel variant strain. The Nano-IC method had a sensitivity of 80% and specificity of 86% for outbreak specimens. Norovirus virus-like particles (VLPs) representing four genotypes (GII.4, GII.10, GII.12, and GII.17) could be detected by this method, demonstrating the potential in clinical screening. However, further modifications to the Nano-IC method are needed in order to improve this sensitivity, which may be achieved by the addition of other broadly reactive Nanobodies to the system. IMPORTANCE We previously identified a Nanobody (termed Nano-85) that bound to a highly conserved region on the norovirus capsid. In this study, the Nanobody was biotinylated and gold conjugated for a lateral flow immunoassay (termed Nano-IC). We showed that the Nano-IC assay was capable of detecting at least four antigenically distinct GII genotypes, including the newly emerging GII.17. In the clinical setting, the

  4. Development of a Nanobody-Based Lateral Flow Immunoassay for Detection of Human Norovirus

    PubMed Central

    Doerflinger, Sylvie Y.; Tabatabai, Julia; Schnitzler, Paul; Farah, Carlo; Rameil, Steffen; Sander, Peter; Koromyslova, Anna

    2016-01-01

    ABSTRACT Human noroviruses are the dominant cause of outbreaks of acute gastroenteritis. These viruses are usually detected by molecular methods, including reverse transcriptase PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Human noroviruses are genetically and antigenically diverse, with two main genogroups that are further subdivided into over 40 different genotypes. During the past decade, genogroup 2 genotype 4 (GII.4) has dominated in most countries, but recently, viruses belonging to GII.17 have increased in prevalence in a number of countries. A number of commercially available ELISAs and lateral flow immunoassays were found to have lower sensitivities to the GII.17 viruses, indicating that the antibodies used in these methods may not have a high level of cross-reactivity. In this study, we developed a rapid Nanobody-based lateral flow immunoassay (Nano-immunochromatography [Nano-IC]) for the detection of human norovirus in clinical specimens. The Nano-IC assay detected virions from two GII.4 norovirus clusters, which included the current dominant strain and a novel variant strain. The Nano-IC method had a sensitivity of 80% and specificity of 86% for outbreak specimens. Norovirus virus-like particles (VLPs) representing four genotypes (GII.4, GII.10, GII.12, and GII.17) could be detected by this method, demonstrating the potential in clinical screening. However, further modifications to the Nano-IC method are needed in order to improve this sensitivity, which may be achieved by the addition of other broadly reactive Nanobodies to the system. IMPORTANCE We previously identified a Nanobody (termed Nano-85) that bound to a highly conserved region on the norovirus capsid. In this study, the Nanobody was biotinylated and gold conjugated for a lateral flow immunoassay (termed Nano-IC). We showed that the Nano-IC assay was capable of detecting at least four antigenically distinct GII genotypes, including the newly emerging GII.17. In the clinical

  5. The simultaneous occurrence of human norovirus and hepatitis E virus in a Norway rat (Rattus norvegicus).

    PubMed

    Wolf, Sandro; Reetz, Jochen; Johne, Reimar; Heiberg, Ann-Charlotte; Petri, Samuel; Kanig, Hanna; Ulrich, Rainer G

    2013-07-01

    Wild rats can be reservoirs and vectors for several human pathogens. An initial RT-PCR screening of the intestinal contents of Norway rats trapped in the sewer system of Copenhagen, Denmark, for caliciviruses revealed the presence of a human norovirus in one of 11 rodents. Subsequent phylogenetic analysis of the ~4.0-kb 3'-terminus of the norovirus genome resulted in the identification of a recombinant GI.b/GI.6 strain. The simultaneous detection of hepatitis E virus-like particles in the feces of this rat by transmission electron microscopy was confirmed by RT-PCR and sequence determination, resulting in the identification of a novel rat hepatitis E virus.

  6. Llama Nanoantibodies with Therapeutic Potential against Human Norovirus Diarrhea

    PubMed Central

    Garaicoechea, Lorena; Aguilar, Andrea; Parra, Gabriel I.; Bok, Marina; Sosnovtsev, Stanislav V.; Canziani, Gabriela; Green, Kim Y.; Bok, Karin; Parreño, Viviana

    2015-01-01

    Noroviruses are a major cause of acute gastroenteritis, but no vaccines or therapeutic drugs are available. Llama-derived single chain antibody fragments (also called VHH) are small, recombinant monoclonal antibodies of 15 kDa with several advantages over conventional antibodies. The aim of this study was to generate recombinant monoclonal VHH specific for the two major norovirus (NoV) genogroups (GI and GII) in order to investigate their potential as immunotherapy for the treatment of NoV diarrhea. To accomplish this objective, two llamas were immunized with either GI.1 (Norwalk-1968) or GII.4 (MD2004) VLPs. After immunization, peripheral blood lymphocytes were collected and used to generate two VHH libraries. Using phage display technology, 10 VHH clones specific for GI.1, and 8 specific for GII.4 were selected for further characterization. All VHH recognized conformational epitopes in the P domain of the immunizing VP1 capsid protein, with the exception of one GII.4 VHH that recognized a linear P domain epitope. The GI.1 VHHs were highly specific for the immunizing GI.1 genotype, with only one VHH cross-reacting with GI.3 genotype. The GII.4 VHHs reacted with the immunizing GII.4 strain and showed a varying reactivity profile among different GII genotypes. One VHH specific for GI.1 and three specific for GII.4 could block the binding of homologous VLPs to synthetic HBGA carbohydrates, saliva, and pig gastric mucin, and in addition, could inhibit the hemagglutination of red blood cells by homologous VLPs. The ability of Nov-specific VHHs to perform well in these surrogate neutralization assays supports their further development as immunotherapy for NoV treatment and immunoprophylaxis. PMID:26267898

  7. Llama nanoantibodies with therapeutic potential against human norovirus diarrhea.

    PubMed

    Garaicoechea, Lorena; Aguilar, Andrea; Parra, Gabriel I; Bok, Marina; Sosnovtsev, Stanislav V; Canziani, Gabriela; Green, Kim Y; Bok, Karin; Parreño, Viviana

    2015-01-01

    Noroviruses are a major cause of acute gastroenteritis, but no vaccines or therapeutic drugs are available. Llama-derived single chain antibody fragments (also called VHH) are small, recombinant monoclonal antibodies of 15 kDa with several advantages over conventional antibodies. The aim of this study was to generate recombinant monoclonal VHH specific for the two major norovirus (NoV) genogroups (GI and GII) in order to investigate their potential as immunotherapy for the treatment of NoV diarrhea. To accomplish this objective, two llamas were immunized with either GI.1 (Norwalk-1968) or GII.4 (MD2004) VLPs. After immunization, peripheral blood lymphocytes were collected and used to generate two VHH libraries. Using phage display technology, 10 VHH clones specific for GI.1, and 8 specific for GII.4 were selected for further characterization. All VHH recognized conformational epitopes in the P domain of the immunizing VP1 capsid protein, with the exception of one GII.4 VHH that recognized a linear P domain epitope. The GI.1 VHHs were highly specific for the immunizing GI.1 genotype, with only one VHH cross-reacting with GI.3 genotype. The GII.4 VHHs reacted with the immunizing GII.4 strain and showed a varying reactivity profile among different GII genotypes. One VHH specific for GI.1 and three specific for GII.4 could block the binding of homologous VLPs to synthetic HBGA carbohydrates, saliva, and pig gastric mucin, and in addition, could inhibit the hemagglutination of red blood cells by homologous VLPs. The ability of Nov-specific VHHs to perform well in these surrogate neutralization assays supports their further development as immunotherapy for NoV treatment and immunoprophylaxis.

  8. Fluorinated TiO₂ as an ambient light-activated virucidal surface coating material for the control of human norovirus.

    PubMed

    Park, Geun Woo; Cho, Min; Cates, Ezra L; Lee, David; Oh, Byung-Taek; Vinjé, Jan; Kim, Jae-Hong

    2014-11-01

    We evaluated the virucidal efficacy of light-activated fluorinated TiO₂ surface coatings on human norovirus and several surrogates (bacteriophage MS2, feline calcivirus (FCV), and murine norovirus (MNV)). Inactivation of viruses on surfaces exposed to a common fluorescent lamp was monitored and the effects of UVA intensity, temperature, and fluoride content were assessed. Destruction of RNA and capsid oxidation were evaluated for human norovirus inocula on the F-TiO₂ surfaces, while contact with the F-TiO₂ surface and exposure to residual UVA radiation of 10 μW cm(-2) for 60 min resulted in infectivity reductions for the norovirus surrogates of 2-3 log₁₀. Infectivity reductions on pristine TiO₂ surfaces in identical conditions were over 2 orders of magnitude lower. Under realistic room lighting conditions, MS2 infectivity declined below the lower detection limit after 12h. Reductions in RNA were generally low, with the exception of GII.4, while capsid protein oxidation likely played a larger role in infectivity loss. Inactivation of norovirus surrogates occurred significantly faster on F-TiO₂ compared to pristine TiO₂ surfaces. The material demonstrated antiviral action against human norovirus surrogates and was shown to effectively inhibit MS2 when exposed to residual UVA present in fluorescent room lighting conditions in a laboratory setting.

  9. Norovirus Narita 104 Virus-Like Particles Expressed in Nicotiana benthamiana Induce Serum and Mucosal Immune Responses

    PubMed Central

    Mathew, Lolita George; Herbst-Kralovetz, Melissa M.; Mason, Hugh S.

    2014-01-01

    Narita 104 virus is a human pathogen belonging to the norovirus (family Caliciviridae) genogroup II. Noroviruses cause epidemic gastroenteritis worldwide. To explore the potential of developing a plant-based vaccine, a plant optimized gene encoding Narita 104 virus capsid protein (NaVCP) was expressed transiently in Nicotiana benthamiana using a tobacco mosaic virus expression system. NaVCP accumulated up to approximately 0.3 mg/g fresh weight of leaf at 4 days postinfection. Initiation of hypersensitive response-like symptoms followed by tissue necrosis necessitated a brief infection time and was a significant factor limiting expression. Transmission electron microscopy of plant-derived NaVCP confirmed the presence of fully assembled virus-like particles (VLPs). In this study, an optimized method to express and partially purify NaVCP is described. Further, partially purified NaVCP was used to immunize mice by intranasal delivery and generated significant mucosal and serum antibody responses. Thus, plant-derived Narita 104 VLPs have potential for use as a candidate subunit vaccine or as a component of a multivalent subunit vaccine, along with other genotype-specific plant-derived VLPs. PMID:24949472

  10. Human norovirus infection of caco-2 cells grown as a three-dimensional tissue structure.

    PubMed

    Straub, Timothy M; Bartholomew, Rachel A; Valdez, Catherine O; Valentine, Nancy B; Dohnalkova, Alice; Ozanich, Richard M; Bruckner-Lea, Cynthia J; Call, Douglas R

    2011-06-01

    Human norovirus (hNoV) infectivity was studied using a three-dimensional model of large intestinal epithelium. Large intestine Caco-2 cells were grown in rotating wall vessel bioreactors for 18-21 days at 37 degrees C and then transferred to 24-well tissue culture plates where they were infected with GI.1 and GII.4 human noroviruses collected from human challenge trials and various outbreak settings, respectively. Compared with uninfected cells, transmission micrographs of norovirus-infected cells displayed evidence of shortening or total loss of apical microvilli, and vacuolization. Quantitative reverse transcription real-time PCR (qRT-PCR) indicated an approximate 2-3 log10 increase in viral RNA copies for the infected cells. A passage experiment examined both the ability for continued viral RNA and viral antigen detection. In the passaged samples 1.01x10(6) copies ml(-1) were detected by qRT-PCR. Immune electron microscopy using primary antibody to hNoV GI.1 capsids in conjunction with 6 nm gold-labelled secondary antibodies was performed on crude cellular lysates. Localization of antibody was observed in infected but not for uninfected cells. Our present findings, coupled with earlier work with the three-dimensional small intestinal INT407 model, demonstrate the utility of 3-D cell culture methods to develop infectivity assays for enteric viruses that do not readily infect mammalian cell cultures.

  11. Comparative Inactivation of Murine Norovirus, Human Adenovirus, and Human JC Polyomavirus by Chlorine in Seawater

    PubMed Central

    de Abreu Corrêa, Adriana; Carratala, Anna; Barardi, Celia Regina Monte; Calvo, Miquel; Bofill-Mas, Sílvia

    2012-01-01

    Viruses excreted by humans affect the commercial and recreational use of coastal water. Shellfish produced in contaminated waters have been linked to many episodes and outbreaks of viral gastroenteritis, as well as other food-borne diseases worldwide. The risk can be reduced by appropriate treatment following harvesting and by depuration. The kinetics of inactivation of murine norovirus 1 and human adenovirus 2 in natural and artificial seawater by free available chlorine was studied by quantifying genomic copies (GC) using quantitative PCR and infectious viral particles (PFU). Human JC polyomavirus Mad4 kinetics were evaluated by quantitative PCR. DNase or RNase were used to eliminate free genomes and assess potential viral infectivity when molecular detection was performed. At 30 min of assay, human adenovirus 2 showed 2.6- and 2.7-log10 GC reductions and a 2.3- and 2.4-log10 PFU reductions in natural and artificial seawater, respectively, and infectious viral particles were still observed at the end of the assay. When DNase was used prior to the nucleic acid extraction the kinetic of inactivation obtained by quantitative PCR was statistically equivalent to the one observed by infectivity assays. For murine norovirus 1, 2.5, and 3.5-log10 GC reductions were observed in natural and artificial seawater, respectively, while no viruses remained infectious after 30 min of contact with chlorine. Regarding JC polyomavirus Mad4, 1.5- and 1.1-log10 GC reductions were observed after 30 min of contact time. No infectivity assays were conducted for this virus. The results obtained provide data that might be applicable to seawater used in shellfish depuration. PMID:22773637

  12. Antigenic Relatedness of Norovirus GII.4 Variants Determined by Human Challenge Sera

    PubMed Central

    Dai, Ying-Chun; Zhang, Xu-Fu; Xia, Ming; Tan, Ming; Quigley, Christina; Lei, Wen; Fang, Hao; Zhong, Weiming; Lee, Bonita; Pang, Xiaoli; Nie, Jun; Jiang, Xi

    2015-01-01

    The GII.4 noroviruses (NoVs) are a single genotype that is responsible for over 50% of NoV gastroenteritis epidemics worldwide. However, GII.4 NoVs have been found to undergo antigenic drifts, likely selected by host herd immunity, which raises an issue for vaccine strategies against NoVs. We previously characterized GII.4 NoV antigenic variations and found significant levels of antigenic relatedness among different GII.4 variants. Further characterization of the genetic and antigenic relatedness of recent GII.4 variants (2008b and 2010 cluster) was performed in this study. The amino acid sequences of the receptor binding interfaces were highly conserved among all GII.4 variants from the past two decades. Using serum samples from patients enrolled in a GII.4 virus challenge study, significant cross-reactivity between major GII.4 variants from 1998 to 2012 was observed using enzyme-linked immunosorbent assays and HBGA receptor blocking assays. The overall abilities of GII.4 NoVs to bind to the A/B/H HBGAs were maintained while their binding affinities to individual ABH antigens varied. These results highlight the importance of human HBGAs in NoV evolution and how conserved antigenic types impact vaccine development against GII.4 variants. PMID:25915764

  13. Prevention and control practices for human noroviruses in long-term care facilities in South Carolina.

    PubMed

    Leone, Cortney M; Jayasekara, Lalani; Sharp, Julia; Fraser, Angela

    2015-12-01

    Long-term care facilities (LTCFs) are the most common setting for human norovirus (HuNoV) outbreak. Our study aimed to determine gaps in prevention and control practices for HuNoV in LTCFs in South Carolina (SC). Two researchers visited a convenience sample of 26 LTCFs in SC during July-November 2013. Directors were interviewed to determine facility prevention and control practices. Relative frequencies and means were calculated using SAS 9.3 (SAS Institute, Cary, NC). Most directors had little knowledge of proper sanitizing and disinfecting products and reported missing written procedures for cleaning staff-visitor bathrooms. Only 18 had recommendations for when residents should wash hands. Many used the wrong products for pathogen removal after vomit-fecal events, had no written procedures for cleaning contaminated soft surfaces, did not remove other individuals during clean-up of vomit-fecal episodes, and did not clean a large area surrounding vomit-fecal episodes. Eighteen did not assign specific staff to care for sick; 16 did not designate specific toilets for sick; and 15 did not restrict visitors during an outbreak. Directors' responses indicated gaps in prevention and control practices for HuNoV in LTCFs in SC. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  14. A Gnotobiotic Pig Model for Determining Human Norovirus Inactivation by High-Pressure Processing.

    PubMed

    Lou, Fangfei; Ye, Mu; Ma, Yuanmei; Li, Xinhui; DiCaprio, Erin; Chen, Haiqiang; Krakowka, Steven; Hughes, John; Kingsley, David; Li, Jianrong

    2015-10-01

    Human norovirus (NoV) is responsible for over 90% of outbreaks of acute nonbacterial gastroenteritis worldwide and accounts for 60% of cases of foodborne illness in the United States. Currently, the infectivity of human NoVs is poorly understood due to the lack of a cell culture system. In this study, we determined the survival of a human NoV genogroup II, genotype 4 (GII.4) strain in seeded oyster homogenates after high-pressure processing (HPP) using a novel receptor binding assay and a gnotobiotic pig model. Pressure conditions of 350 MPa at 0°C for 2 min led to a 3.7-log10 reduction in the number of viral RNA copies in oysters, as measured by the porcine gastric mucin-conjugated magnetic bead (PGM-MB) binding assay and real-time RT-PCR, whereas pressure conditions of 350 MPa at 35°C for 2 min achieved only a 1-log10 reduction in the number of RNA copies. Newborn gnotobiotic piglets orally fed oyster homogenate treated at 350 MPa and 0°C for 2 min did not have viral RNA shedding in feces, histologic lesions, or viral replication in the small intestine. In contrast, gnotobiotic piglets fed oysters treated at 350 MPa and 35°C for 2 min had high levels of viral shedding in feces and exhibited significant histologic lesions and viral replication in the small intestine. Collectively, these data demonstrate that (i) human NoV survival estimated by an in vitro PGM-MB virus binding assay is consistent with the infectivity determined by an in vivo gnotobiotic piglet model and (ii) HPP is capable of inactivating a human NoV GII.4 strain at commercially acceptable pressure levels. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. A Gnotobiotic Pig Model for Determining Human Norovirus Inactivation by High-Pressure Processing

    PubMed Central

    Lou, Fangfei; Ye, Mu; Ma, Yuanmei; Li, Xinhui; DiCaprio, Erin; Chen, Haiqiang; Krakowka, Steven; Hughes, John; Kingsley, David

    2015-01-01

    Human norovirus (NoV) is responsible for over 90% of outbreaks of acute nonbacterial gastroenteritis worldwide and accounts for 60% of cases of foodborne illness in the United States. Currently, the infectivity of human NoVs is poorly understood due to the lack of a cell culture system. In this study, we determined the survival of a human NoV genogroup II, genotype 4 (GII.4) strain in seeded oyster homogenates after high-pressure processing (HPP) using a novel receptor binding assay and a gnotobiotic pig model. Pressure conditions of 350 MPa at 0°C for 2 min led to a 3.7-log10 reduction in the number of viral RNA copies in oysters, as measured by the porcine gastric mucin-conjugated magnetic bead (PGM-MB) binding assay and real-time RT-PCR, whereas pressure conditions of 350 MPa at 35°C for 2 min achieved only a 1-log10 reduction in the number of RNA copies. Newborn gnotobiotic piglets orally fed oyster homogenate treated at 350 MPa and 0°C for 2 min did not have viral RNA shedding in feces, histologic lesions, or viral replication in the small intestine. In contrast, gnotobiotic piglets fed oysters treated at 350 MPa and 35°C for 2 min had high levels of viral shedding in feces and exhibited significant histologic lesions and viral replication in the small intestine. Collectively, these data demonstrate that (i) human NoV survival estimated by an in vitro PGM-MB virus binding assay is consistent with the infectivity determined by an in vivo gnotobiotic piglet model and (ii) HPP is capable of inactivating a human NoV GII.4 strain at commercially acceptable pressure levels. PMID:26187968

  16. Vomiting as a Symptom and Transmission Risk in Norovirus Illness: Evidence from Human Challenge Studies

    PubMed Central

    Kirby, Amy E.; Streby, Ashleigh; Moe, Christine L.

    2016-01-01

    Background In the US, noroviruses are estimated to cause 21 million cases annually with economic losses reaching $2 billion. Outbreak investigations frequently implicate vomiting as a major transmission risk. However, little is known about the characteristics of vomiting as a symptom or the amount of virus present in emesis. Methodology and Principal Findings Emesis samples and symptomology data were obtained from previous norovirus human challenge studies with GI.1 Norwalk virus, GII.2 Snow Mountain virus, and a pilot study with GII.1 Hawaii virus. Viral titers in emesis were determined using strain-specific quantitative RT-PCR. In all four studies, vomiting was common with 40–100% of infected subjects vomiting at least once. However, only 45% of subjects with vomiting also had diarrhea. Most of the emesis samples had detectable virus and the mean viral titers were 8.0 x 105 and 3.9 x 104 genomic equivalent copies (GEC)/ml for GI and GII viruses, respectively (p = 0.02). Sample pH was correlated with GII.2 Snow Mountain virus detection. Conclusions and Significance Half of all subjects with symptomatic infection experienced vomiting and the average subject shed 1.7 x 108 GEC in emesis. Unlike shedding through stool, vomiting is more likely to result in significant environmental contamination, leading to transmission through fomites and airborne droplets. This quantitative data will be critical for risk assessment studies to further understand norovirus transmission and develop effective control measures. The correlation between sample pH and virus detection is consistent with a single site of virus replication in the small intestine and stomach contents becoming contaminated by intestinal reflux. Additionally, the frequency of vomiting without concurrent diarrhea suggests that epidemiology studies that enroll subjects based on the presence of diarrhea may be significantly underestimating the true burden of norovirus disease. PMID:27116105

  17. Recent advances in understanding noroviruses

    PubMed Central

    Bartnicki, Eric; Cunha, Juliana Bragazzi; Kolawole, Abimbola O.; Wobus, Christiane E.

    2017-01-01

    Noroviruses are the leading cause of acute gastroenteritis around the world. An individual living in the United States is estimated to develop norovirus infection five times in his or her lifetime. Despite this, there is currently no antiviral or vaccine to combat the infection, in large part because of the historical lack of cell culture and small animal models. However, the last few years of norovirus research were marked by a number of ground-breaking advances that have overcome technical barriers and uncovered novel aspects of norovirus biology. Foremost among them was the development of two different in vitro culture systems for human noroviruses. Underappreciated was the notion that noroviruses infect cells of the immune system as well as epithelial cells within the gastrointestinal tract and that human norovirus infection of enterocytes requires or is promoted by the presence of bile acids. Furthermore, two proteinaceous receptors are now recognized for murine norovirus, marking the first discovery of a functional receptor for any norovirus. Recent work further points to a role for certain bacteria, including those found in the gut microbiome, as potential modulators of norovirus infection in the host, emphasizing the importance of interactions with organisms from other kingdoms of life for viral pathogenesis. Lastly, we will highlight the adaptation of drop-based microfluidics to norovirus research, as this technology has the potential to reveal novel insights into virus evolution. This review aims to summarize these new findings while also including possible future directions. PMID:28163914

  18. Norovirus gene expression and replication.

    PubMed

    Thorne, Lucy G; Goodfellow, Ian G

    2014-02-01

    Noroviruses are small, positive-sense RNA viruses within the family Caliciviridae, and are now accepted widely as a major cause of acute gastroenteritis in both developed and developing countries. Despite their impact, our understanding of the life cycle of noroviruses has lagged behind that of other RNA viruses due to the inability to culture human noroviruses (HuNVs). Our knowledge of norovirus biology has improved significantly over the past decade as a result of numerous technological advances. The use of a HuNV replicon, improved biochemical and cell-based assays, combined with the discovery of a murine norovirus capable of replication in cell culture, has improved greatly our understanding of the molecular mechanisms of norovirus genome translation and replication, as well as the interaction with host cell processes. In this review, the current state of knowledge of the intracellular life of noroviruses is discussed with particular emphasis on the mechanisms of viral gene expression and viral genome replication.

  19. Epidemiology, prevention, and control of the number one foodborne illness: human norovirus.

    PubMed

    Dicaprio, Erin; Ma, Yuanmei; Hughes, John; Li, Jianrong

    2013-09-01

    Human norovirus (NoV) is the number one cause of foodborne illness. Despite tremendous research efforts, human NoV is still poorly understood and understudied. There is no effective measure to eliminate this virus from food and the environment. Future research efforts should focus on developing: (1) an efficient cell culture system and a robust animal model, (2) rapid and sensitive detection methods, (3) novel sanitizers and control interventions, and (4) vaccines and antiviral drugs. Furthermore, there is an urgent need to build multidisciplinary and multi-institutional teams to combat this important biodefense agent.

  20. Inactivation Kinetics and Mechanism of a Human Norovirus Surrogate on Stainless Steel Coupons via Chlorine Dioxide Gas.

    PubMed

    Yeap, Jia Wei; Kaur, Simran; Lou, Fangfei; DiCaprio, Erin; Morgan, Mark; Linton, Richard; Li, Jianrong

    2015-10-16

    Acute gastroenteritis caused by human norovirus is a significant public health issue. Fresh produce and seafood are examples of high-risk foods associated with norovirus outbreaks. Food contact surfaces also have the potential to harbor noroviruses if exposed to fecal contamination, aerosolized vomitus, or infected food handlers. Currently, there is no effective measure to decontaminate norovirus on food contact surfaces. Chlorine dioxide (ClO2) gas is a strong oxidizer and is used as a decontaminating agent in food processing plants. The objective of this study was to determine the kinetics and mechanism of ClO2 gas inactivation of a norovirus surrogate, murine norovirus 1 (MNV-1), on stainless steel (SS) coupons. MNV-1 was inoculated on SS coupons at the concentration of 10(7) PFU/coupon. The samples were treated with ClO2 gas at 1, 1.5, 2, 2.5, and 4 mg/liter for up to 5 min at 25°C and a relative humidity of 85%, and virus survival was determined by plaque assay. Treatment of the SS coupons with ClO2 gas at 2 mg/liter for 5 min and 2.5 mg/liter for 2 min resulted in at least a 3-log reduction in MNV-1, while no infectious virus was recovered at a concentration of 4 mg/liter even within 1 min of treatment. Furthermore, it was found that the mechanism of ClO2 gas inactivation included degradation of viral protein, disruption of viral structure, and degradation of viral genomic RNA. In conclusion, treatment with ClO2 gas can serve as an effective method to inactivate a human norovirus surrogate on SS contact surfaces.

  1. Inactivation Kinetics and Mechanism of a Human Norovirus Surrogate on Stainless Steel Coupons via Chlorine Dioxide Gas

    PubMed Central

    Yeap, Jia Wei; Kaur, Simran; Lou, Fangfei; DiCaprio, Erin; Morgan, Mark; Linton, Richard

    2015-01-01

    Acute gastroenteritis caused by human norovirus is a significant public health issue. Fresh produce and seafood are examples of high-risk foods associated with norovirus outbreaks. Food contact surfaces also have the potential to harbor noroviruses if exposed to fecal contamination, aerosolized vomitus, or infected food handlers. Currently, there is no effective measure to decontaminate norovirus on food contact surfaces. Chlorine dioxide (ClO2) gas is a strong oxidizer and is used as a decontaminating agent in food processing plants. The objective of this study was to determine the kinetics and mechanism of ClO2 gas inactivation of a norovirus surrogate, murine norovirus 1 (MNV-1), on stainless steel (SS) coupons. MNV-1 was inoculated on SS coupons at the concentration of 107 PFU/coupon. The samples were treated with ClO2 gas at 1, 1.5, 2, 2.5, and 4 mg/liter for up to 5 min at 25°C and a relative humidity of 85%, and virus survival was determined by plaque assay. Treatment of the SS coupons with ClO2 gas at 2 mg/liter for 5 min and 2.5 mg/liter for 2 min resulted in at least a 3-log reduction in MNV-1, while no infectious virus was recovered at a concentration of 4 mg/liter even within 1 min of treatment. Furthermore, it was found that the mechanism of ClO2 gas inactivation included degradation of viral protein, disruption of viral structure, and degradation of viral genomic RNA. In conclusion, treatment with ClO2 gas can serve as an effective method to inactivate a human norovirus surrogate on SS contact surfaces. PMID:26475110

  2. Norovirus Infection

    MedlinePlus

    ... has a norovirus infection Noroviruses are difficult to wipe out because they can withstand hot and cold ... especially after using the toilet or changing a diaper. Avoid contaminated food and water, including food that ...

  3. Quantification of human norovirus GII, human adenovirus, and fecal indicator organisms in wastewater used for irrigation in Accra, Ghana.

    PubMed

    Silverman, Andrea I; Akrong, Mark O; Amoah, Philip; Drechsel, Pay; Nelson, Kara L

    2013-09-01

    Quantitative microbial risk assessment (QMRA) is frequently used to estimate health risks associated with wastewater irrigation and requires pathogen concentration estimates as inputs. However, human pathogens, such as viruses, are rarely quantified in water samples, and simple relationships between fecal indicator bacteria and pathogen concentrations are used instead. To provide data that can be used to refine QMRA models of wastewater-fed agriculture in Accra, stream, drain, and waste stabilization pond waters used for irrigation were sampled and analyzed for concentrations of fecal indicator microorganisms (human-specific Bacteroidales, Escherichia coli, enterococci, thermotolerant coliform, and somatic and F+ coliphages) and two human viruses (adenovirus and norovirus genogroup II). E. coli concentrations in all samples exceeded limits suggested by the World Health Organization, and human-specific Bacteroidales was found in all but one sample, suggesting human fecal contamination. Human viruses were detected in 16 out of 20 samples, were quantified in 12, and contained 2-3 orders of magnitude more norovirus than predicted by norovirus to E. coli concentration ratios assumed in recent publications employing indicator-based QMRA. As wastewater irrigation can be beneficial for farmers and municipalities, these results should not discourage water reuse in agriculture, but provide motivation and targets for wastewater treatment before use on farms.

  4. Engineering Bacterial Surface Displayed Human Norovirus Capsid Proteins: A Novel System to Explore Interaction Between Norovirus and Ligands

    PubMed Central

    Niu, Mengya; Yu, Qianqian; Tian, Peng; Gao, Zhiyong; Wang, Dapeng; Shi, Xianming

    2015-01-01

    Human noroviruses (HuNoVs) are major contributors to acute nonbacterial gastroenteritis outbreaks. Many aspects of HuNoVs are poorly understood due to both the current inability to culture HuNoVs, and the lack of efficient small animal models. Surrogates for HuNoVs, such as recombinant viral like particles (VLPs) expressed in eukaryotic system or P particles expressed in prokaryotic system, have been used for studies in immunology and interaction between the virus and its receptors. However, it is difficult to use VLPs or P particles to collect or isolate potential ligands binding to these recombinant capsid proteins. In this study, a new strategy was used to collect HuNoVs binding ligands through the use of ice nucleation protein (INP) to display recombinant capsid proteins of HuNoVs on bacterial surfaces. The viral protein-ligand complex could be easily separated by a low speed centrifugation step. This system was also used to explore interaction between recombinant capsid proteins of HuNoVs and their receptors. In this system, the VP1 capsid encoding gene (ORF2) and the protruding domain (P domain) encoding gene (3′ terminal fragment of ORF2) of HuNoVs GI.1 and GII.4 were fused with 5′ terminal fragment of INP encoding gene (inaQn). The results demonstrated that the recombinant VP1 and P domains of HuNoVs were expressed and anchored on the surface of Escherichia coli BL21 cells after the bacteria were transformed with the corresponding plasmids. Both cell surface displayed VP1 and P domains could be recognized by HuNoVs specific antibodies and interact with the viral histo-blood group antigens receptors. In both cases, displayed P domains had better binding abilities than VP1. This new strategy of using displayed HuNoVs capsid proteins on the bacterial surface could be utilized to separate HuNoVs binding components from complex samples, to investigate interaction between the virus and its receptors, as well as to develop an oral vaccine for HuNoVs. PMID

  5. Recent Advances in Understanding Norovirus Pathogenesis

    PubMed Central

    Karst, Stephanie M.; Tibbetts, Scott A.

    2016-01-01

    Noroviruses constitute a family of ubiquitous and highly efficient human pathogens. In spite of decades of dedicated research, human noroviruses remain a major cause of gastroenteritis and severe diarrheal disease around the world. Recent findings have begun to unravel the complex mechanisms that regulate norovirus pathogenesis and persistent infection, including the important interplay between the virus, the host immune system, and commensal bacteria. Herein, we will summarize recent research developments regarding norovirus cell tropism, the use of M cells, and commensal bacteria to facilitate norovirus infection, and virus, host, and bacterial determinants of persistent norovirus infections. PMID:27110852

  6. Evidence for human norovirus infection of dogs in the United kingdom.

    PubMed

    Caddy, Sarah L; de Rougemont, Alexis; Emmott, Edward; El-Attar, Laila; Mitchell, Judy A; Hollinshead, Michael; Belliot, Gael; Brownlie, Joe; Le Pendu, Jacques; Goodfellow, Ian

    2015-06-01

    Human noroviruses (HuNoVs) are a major cause of viral gastroenteritis, with an estimated 3 million cases per year in the United Kingdom. HuNoVs have recently been isolated from pet dogs in Europe (M. Summa, C.-H. von Bonsdorff, and L. Maunula, J Clin Virol 53:244-247, 2012, http://dx.doi.org/10.1016/j.jcv.2011.12.014), raising concerns about potential zoonotic infections. With 31% of United Kingdom households owning a dog, this could prove to be an important transmission route. To examine this risk, canine tissues were studied for their ability to bind to HuNoV in vitro. In addition, canine stool samples were analyzed for the presence of viral nucleic acid, and canine serum samples were tested for the presence of anti-HuNoV antibodies. The results showed that seven different genotypes of HuNoV virus-like particles (VLPs) can bind to canine gastrointestinal tissue, suggesting that infection is at least theoretically possible. Although HuNoV RNA was not identified in stool samples from 248 dogs, serological evidence of previous exposure to HuNoV was obtained in 43/325 canine serum samples. Remarkably, canine seroprevalence for different HuNoV genotypes mirrored the seroprevalence in the human population. Though entry and replication within cells have not been demonstrated, the canine serological data indicate that dogs produce an immune response to HuNoV, implying productive infection. In conclusion, this study reveals zoonotic implications for HuNoV, and to elucidate the significance of this finding, further epidemiological and molecular investigations will be essential.

  7. Evidence for Human Norovirus Infection of Dogs in the United Kingdom

    PubMed Central

    Emmott, Edward; El-Attar, Laila; Mitchell, Judy A.; Hollinshead, Michael; Belliot, Gael; Brownlie, Joe; Le Pendu, Jacques; Goodfellow, Ian

    2015-01-01

    Human noroviruses (HuNoVs) are a major cause of viral gastroenteritis, with an estimated 3 million cases per year in the United Kingdom. HuNoVs have recently been isolated from pet dogs in Europe (M. Summa, C.-H. von Bonsdorff, and L. Maunula, J Clin Virol 53:244–247, 2012, http://dx.doi.org/10.1016/j.jcv.2011.12.014), raising concerns about potential zoonotic infections. With 31% of United Kingdom households owning a dog, this could prove to be an important transmission route. To examine this risk, canine tissues were studied for their ability to bind to HuNoV in vitro. In addition, canine stool samples were analyzed for the presence of viral nucleic acid, and canine serum samples were tested for the presence of anti-HuNoV antibodies. The results showed that seven different genotypes of HuNoV virus-like particles (VLPs) can bind to canine gastrointestinal tissue, suggesting that infection is at least theoretically possible. Although HuNoV RNA was not identified in stool samples from 248 dogs, serological evidence of previous exposure to HuNoV was obtained in 43/325 canine serum samples. Remarkably, canine seroprevalence for different HuNoV genotypes mirrored the seroprevalence in the human population. Though entry and replication within cells have not been demonstrated, the canine serological data indicate that dogs produce an immune response to HuNoV, implying productive infection. In conclusion, this study reveals zoonotic implications for HuNoV, and to elucidate the significance of this finding, further epidemiological and molecular investigations will be essential. PMID:25832298

  8. Virucidal Effect of Cold Atmospheric Gaseous Plasma on Feline Calicivirus, a Surrogate for Human Norovirus

    PubMed Central

    Aboubakr, Hamada A.; Williams, Paul; Gangal, Urvashi; Youssef, Mohammed M.; El-Sohaimy, Sobhy A. A.; Bruggeman, Peter J.

    2015-01-01

    Minimal food-processing methods are not effective against foodborne viruses, such as human norovirus (NV). It is important, therefore, to explore novel nonthermal technologies for decontamination of foods eaten fresh, minimally processed and ready-to-eat foods, and food contact surfaces. We studied the in vitro virucidal activity of cold atmospheric gaseous plasma (CGP) against feline calicivirus (FCV), a surrogate of NV. Factors affecting the virucidal activity of CGP (a so-called radio frequency atmospheric pressure plasma jet) were the plasma generation power, the exposure time and distance, the plasma feed gas mixture, and the virus suspension medium. Exposure to 2.5-W argon (Ar) plasma caused a 5.55 log10 unit reduction in the FCV titer within 120 s. The reduction in the virus titer increased with increasing exposure time and decreasing exposure distance. Of the four plasma gas mixtures studied (Ar, Ar plus 1% O2, Ar plus 1% dry air, and Ar plus 0.27% water), Ar plus 1% O2 plasma treatment had the highest virucidal effect: more than 6.0 log10 units of the virus after 15 s of exposure. The lowest virus reduction was observed with Ar plus 0.27% water plasma treatment (5 log10 unit reduction after 120 s). The highest reduction in titer was observed when the virus was suspended in distilled water. Changes in temperature and pH and formation of H2O2 were not responsible for the virucidal effect of plasma. The oxidation of viral capsid proteins by plasma-produced reactive oxygen and nitrogen species in the solution was thought to be responsible for the virucidal effect. In conclusion, CGP exhibits virucidal activity in vitro and has the potential to combat viral contamination in foods and on food preparation surfaces. PMID:25795667

  9. Virucidal effect of cold atmospheric gaseous plasma on feline calicivirus, a surrogate for human norovirus.

    PubMed

    Aboubakr, Hamada A; Williams, Paul; Gangal, Urvashi; Youssef, Mohammed M; El-Sohaimy, Sobhy A A; Bruggeman, Peter J; Goyal, Sagar M

    2015-06-01

    Minimal food-processing methods are not effective against foodborne viruses, such as human norovirus (NV). It is important, therefore, to explore novel nonthermal technologies for decontamination of foods eaten fresh, minimally processed and ready-to-eat foods, and food contact surfaces. We studied the in vitro virucidal activity of cold atmospheric gaseous plasma (CGP) against feline calicivirus (FCV), a surrogate of NV. Factors affecting the virucidal activity of CGP (a so-called radio frequency atmospheric pressure plasma jet) were the plasma generation power, the exposure time and distance, the plasma feed gas mixture, and the virus suspension medium. Exposure to 2.5-W argon (Ar) plasma caused a 5.55 log10 unit reduction in the FCV titer within 120 s. The reduction in the virus titer increased with increasing exposure time and decreasing exposure distance. Of the four plasma gas mixtures studied (Ar, Ar plus 1% O2, Ar plus 1% dry air, and Ar plus 0.27% water), Ar plus 1% O2 plasma treatment had the highest virucidal effect: more than 6.0 log10 units of the virus after 15 s of exposure. The lowest virus reduction was observed with Ar plus 0.27% water plasma treatment (5 log10 unit reduction after 120 s). The highest reduction in titer was observed when the virus was suspended in distilled water. Changes in temperature and pH and formation of H2O2 were not responsible for the virucidal effect of plasma. The oxidation of viral capsid proteins by plasma-produced reactive oxygen and nitrogen species in the solution was thought to be responsible for the virucidal effect. In conclusion, CGP exhibits virucidal activity in vitro and has the potential to combat viral contamination in foods and on food preparation surfaces.

  10. Surface plasmon resonance biosensor for detection of feline calicivirus, a surrogate for norovirus

    USDA-ARS?s Scientific Manuscript database

    The human noroviruses are the most common non-bacterial cause of gastroenteritis and are responsible for as much as 50% of all gastroenteritis outbreaks worldwide. Norovirus (NoV), a single stranded RNA virus, is highly contagious with an infectious dose of less than 100 viral particles. While techn...

  11. Inactivation of human norovirus and Tulane virus in simple mediums and fresh whole strawberries by ionizing radiation

    USDA-ARS?s Scientific Manuscript database

    Human norovirus (NoV) is a major cause of fresh produce associated outbreaks and human NoV in irrigation water can potentially lead to viral internalization in fresh produce. Therefore, there is a need to develop novel intervention strategies to target internalized viral pathogens while maintainin...

  12. Antiviral Effect of Korean Red Ginseng Extract and Ginsenosides on Murine Norovirus and Feline Calicivirus as Surrogates for Human Norovirus

    PubMed Central

    Lee, Min Hwa; Lee, Bog-Hieu; Jung, Ji-Youn; Cheon, Doo-Sung; Kim, Kyung-Tack; Choi, Changsun

    2011-01-01

    Korean red ginseng has been studied various biological activities such as immune, anti-oxidative, anti-microbial, and anticancer activities but antiviral mechanism needs further studies. In this study, we aimed to examine the antiviral effects of Korea red ginseng extract and ginsenosides on norovirus surrogate, including murine norovirus (MNV) and feline calicivirus (FCV). We evaluated the pre-, co-, and post-treatment effects of Korean red ginseng (KRG), ginsenosides Rb1 and Rg1. To measure the antiviral effect and cytotoxicity of KRG extract, and ginsenosides Rb1 and Rg1, we treated Crandell-Reese Feline Kidney for FCV or RAW264.7 cells for MNV with concentrations of 0, 5, 6.7, 10, 20 ug/mL total saponin. There was cytotoxic effect in the highest concentration 20 ug/mL of KRG extract so this concentration was excluded in this study. The FCV titer was significantly reduced to 0.23-0.83 log10 50% tissue culture infectious dose (TCID50)/mL in groups pre-treated with red ginseng extract or ginsenosides. The titer of MNV was significantly reduced to 0.37-1.48 log10 TCID50/mL in groups pre-treated with red ginseng extract or ginsenosides. However, there was no observed antiviral effect in groups co-treated or post-treated with KRG and its constituents. Our data suggest that KRG extract has an antiviral effect against norovirus surrogates. The antiviral mechanisms of KRG and ginsenosides should be addressed in future studies. PMID:23717088

  13. Norovirus in a United States virgin islands resort: outbreak investigation, response, and costs.

    PubMed

    Leshem, Eyal; Gastañaduy, Paul A; Trivedi, Tarak; Laufer Halpin, Alison; Pringle, Jeshua; Lang, Francine; Gregoricus, Nicole; Vinjé, Jan; Behravesh, Casey Barton; Parashar, Umesh; Hall, Aron J

    2016-05-01

    During 8-20 April 2012, an outbreak of gastrointestinal illness occurred among guests and employees of a resort hotel in St. Thomas, US Virgin Islands. We describe outbreak characteristics, and estimate indirect (non-medical) costs to travellers. Employees who met the case definition were interviewed and provided stool samples. Samples were tested for norovirus by real-time reverse-transcription polymerase chain reaction. Guests were asked to complete a survey aimed to identify and characterize cases, and to estimate quality adjusted vacation days (QAVD) lost. Overall, 66 persons (20 employees and 46 guests) met the probable case definition. The first reported illness onset occurred in a hotel employee on 8 April, while the first reported onset in a guest occurred on 13 April. An employee suffered a public diarrhoea incident on 13 April in the central kitchen, followed by illness onset in the next day among employees that assisted with the clean-up. On 15 April, after 10 guests reported ill, the hotel implemented an outbreak response protocol instructing ill employees to take a 3-day leave, and obtain medical clearance prior to resuming work. Ill guests were advised to self-isolate, and rapid cleaning of public areas and guest rooms where suspected contamination occurred was implemented. We estimated that 65 QAVDs were lost by 43 guests (1.5 days/guest). Using an approximate cost of $450 per vacation day, we estimated indirect illness cost at $675 per guest case. Seven (64%) of 11 cases' stool specimens were positive for norovirus genotype GII.4 Den Haag. A norovirus outbreak in a resort hotel resulted in substantial indirect costs and loss of vacation days to ill travellers. We recommend outbreak control measures including exclusion of ill employees, until ≥48-72 h after resolution of symptoms, self-isolation of ill guests and appropriate cleaning in hotel-associated norovirus outbreaks. Published by Oxford University Press on behalf of the International

  14. Exploration of the metal coordination region of concanavalin A for its interaction with human norovirus.

    PubMed

    Kim, Duwoon; Lee, Hee-Min; Oh, Kyung-Seo; Ki, Ah Young; Protzman, Rachael A; Kim, Dongkyun; Choi, Jong-Soon; Kim, Min Ji; Kim, Sung Hyun; Vaidya, Bipin; Lee, Seung Jae; Kwon, Joseph

    2017-06-01

    Rapid methods for the detection and clinical treatment of human norovirus (HuNoV) are needed to control foodborne disease outbreaks, but reliable techniques that are fast and sensitive enough to detect small amounts of HuNoV in food and aquatic environments are not yet available. We explore the interactions between HuNoV and concanavalin A (Con A), which could facilitate the development of a sensitive detection tool for HuNoV. Biophysical studies including hydrogen/deuterium exchange (HDX) mass spectrometry and surface plasmon resonance (SPR) revealed that when the metal coordinated region of Con A, which spans Asp16 to His24, is converted to nine alanine residues (mCon A(MCR)), the affinity for HuNoV (GII.4) diminishes, demonstrating that this Ca(2+) and Mn(2+) coordinated region is responsible for the observed virus-protein interaction. The mutated carbohydrate binding region of Con A (mCon A(CBR)) does not affect binding affinity significantly, indicating that MCR of Con A is a major region of interaction to HuNoV (GII.4). The results further contribute to the development of a HuNoV concentration tool, Con A-immobilized polyacrylate beads (Con A-PAB), for rapid detection of genotypes from genogroups I and II (GI and GII). This method offers many advantages over currently available methods, including a short concentration time. HuNov (GI and GII) can be detected in just 15 min with 90% recovery through Con A-PAB application. In addition, this method can be used over a wide range of pH values (pH 3.0 - 10.0). Overall, this rapid and sensitive detection of HuNoV (GI and GII) will aid in the prevention of virus transmission pathways, and the method developed here may have applicability for other foodborne viral infections.

  15. Advances in Norovirus Biology

    PubMed Central

    Karst, Stephanie M.; Wobus, Christiane E.; Goodfellow, Ian G.; Green, Kim Y.

    2014-01-01

    Human noroviruses are a major cause of epidemic and sporadic gastroenteritis worldwide, and can chronically infect immunocompromised patients. Efforts to develop effective vaccines and antivirals have been hindered by the uncultivable nature and extreme genetic diversity of human noroviruses. Although they remain a particularly challenging pathogen to study, recent advances in norovirus animal models and in vitro cultivation systems have led to an increased understanding of norovirus molecular biology and replication, pathogenesis, cell tropism, and innate and adaptive immunity. Furthermore, clinical trials of vaccines consisting of nonreplicating virus-like particles have shown promise. In this review, we summarize these recent advances and discuss controversies in the field, which is rapidly progressing towards generation of antiviral agents and increasingly effective vaccines. PMID:24922570

  16. Advances in norovirus biology.

    PubMed

    Karst, Stephanie M; Wobus, Christiane E; Goodfellow, Ian G; Green, Kim Y; Virgin, Herbert W

    2014-06-11

    Human noroviruses are a major cause of epidemic and sporadic gastroenteritis worldwide and can chronically infect immunocompromised patients. Efforts to develop effective vaccines and antivirals have been hindered by the uncultivable nature and extreme genetic diversity of human noroviruses. Although they remain a particularly challenging pathogen to study, recent advances in norovirus animal models and in vitro cultivation systems have led to an increased understanding of norovirus molecular biology and replication, pathogenesis, cell tropism, and innate and adaptive immunity. Furthermore, clinical trials of vaccines consisting of nonreplicating virus-like particles have shown promise. In this review, we summarize these recent advances and discuss controversies in the field, which is rapidly progressing toward generation of antiviral agents and increasingly effective vaccines. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Decoding norovirus infection in Crohn's disease.

    PubMed

    Chamaillard, Mathias; Cesaro, Annabelle; Lober, Pierre-Emmanuel; Hober, Didier

    2014-04-01

    Although a causing viral infectious agent remains untraceable in Crohn's disease, most recent genome-wide association studies have linked the FUT2 W143X mutation (resulting in asymptomatic norovirus infection) with the pathogenesis of Crohn's ileitis and with vitamin B12 deficiency (i.e., a known risk factor for Crohn's disease with ileal involvement). In line with these findings, host variations in additional genes involved in host response to norovirus infection (such as ATG16L1 and NOD2) predispose humans to Crohn's ileitis. One may therefore presume that asymptomatic norovirus infection may contribute to disruption of the stability of the gut microbiota leading to Crohn's ileitis. These paradigms highlight not only the need to revisit the potential transmissibility of Crohn's disease, but also potential safety issues of forthcoming clinical trials on human probiotic infusions in Crohn's ileitis by rigorous donors screening program.

  18. The virucidal effect against murine norovirus and feline calicivirus as surrogates for human norovirus by ethanol-based sanitizers.

    PubMed

    Shimizu-Onda, Yuko; Akasaka, Tempei; Yagyu, Fumihiro; Komine-Aizawa, Shihoko; Tohya, Yukinobu; Hayakawa, Satoshi; Ushijima, Hiroshi

    2013-08-01

    This study examined the virucidal effects of five types of alcohol-based sanitizers including malic acid and sodium malate, or monoethanolamin, in 58 vol % ethanol (pH 4.0, pH 7.1, pH 11.8), 65 vol % ethanol (pH 4.2), and 75 vol % ethanol (pH 4.4) against murine norovirus (MNV) and feline calicivirus (FCV). The virus titer of MNV was reduced in an ethanol dose-dependent manner under the same pH (about 4.0) condition. Virucidal effect against MNV was correlated with pH when the concentration of ethanol was constant (58 vol %). All the ethanol-based sanitizers provided sufficient virucidal effects against FCV. In conclusion, the virucidal effect of the ethanol-based sanitizer at low concentration of ethanol against norovirus (NoV) is increased when the pH is adjusted to a neutral state.

  19. Enzyme kinetics of the human norovirus protease control virus polyprotein processing order.

    PubMed

    May, Jared; Korba, Brent; Medvedev, Alexei; Viswanathan, Prasanth

    2013-09-01

    The human norovirus (NoV) polyprotein is cleaved into mature non-structural proteins by both mature NoV protease (Pro, NS6) and its un-cleaved precursor (ProPol, NS6-7). Processing order is well-established with 'early' and 'late' cleavages, but the governing enzymatic mechanisms are unknown. Enzyme kinetics of a GII Pro and ProPol were analyzed using synthetic peptides representing the five natural polyprotein cleavage sites. The relative efficiency of cleavage of the individual peptides was consistent with established polyprotein processing order, and primarily correlated with enzyme turnover (kcat). Enzymatic efficiencies (kcat/Km) of ProPol at all five sites were equivalent to, or greater than, that of Pro. Binding affinities (Km) for the two least efficiently cleaved sites (p20/VPg, VPg/Pro) were 2-4-fold higher than the other sites. This work further defines the role of ProPol in NoV polyprotein cleavage, and demonstrates that human norovirus polyprotein processing order is primarily an inherent property of enzymatic activity. © 2013 Published by Elsevier Inc.

  20. In Vitro Antiviral Activity of Clove and Ginger Aqueous Extracts against Feline Calicivirus, a Surrogate for Human Norovirus.

    PubMed

    Aboubakr, Hamada A; Nauertz, Andrew; Luong, Nhungoc T; Agrawal, Shivani; El-Sohaimy, Sobhy A A; Youssef, Mohammed M; Goyal, Sagar M

    2016-06-01

    Foodborne viruses, particularly human norovirus, are a concern for public health, especially in fresh vegetables and other minimally processed foods that may not undergo sufficient decontamination. It is necessary to explore novel nonthermal techniques for preventing foodborne viral contamination. In this study, aqueous extracts of six raw food materials (flower buds of clove, fenugreek seeds, garlic and onion bulbs, ginger rhizomes, and jalapeño peppers) were tested for antiviral activity against feline calicivirus (FCV) as a surrogate for human norovirus. The antiviral assay was performed using dilutions of the extracts below the maximum nontoxic concentrations of the extracts to the host cells of FCV, Crandell-Reese feline kidney (CRFK) cells. No antiviral effect was seen when the host cells were pretreated with any of the extracts. However, pretreatment of FCV with nondiluted clove and ginger extracts inactivated 6.0 and 2.7 log of the initial titer of the virus, respectively. Also, significant dosedependent inactivation of FCV was seen when host cells were treated with clove and ginger extracts at the time of infection or postinfection at concentrations equal to or lower than the maximum nontoxic concentrations. By comprehensive two-dimensional gas chromatography-mass spectrometry analysis, eugenol (29.5%) and R-(-)-1,2-propanediol (10.7%) were identified as the major components of clove and ginger extracts, respectively. The antiviral effect of the pure eugenol itself was tested; it showed antiviral activity similar to that of clove extract, albeit at a lower level, which indicates that some other clove extract constituents, along with eugenol, are responsible for inactivation of FCV. These results showed that the aqueous extracts of clove and ginger hold promise for prevention of foodborne viral contamination.

  1. Evaluation of chlorine treatment levels on inactivation of human norovirus and MS2 bacteriophage during sewage treatment

    USDA-ARS?s Scientific Manuscript database

    This study examined the inactivation of human norovirus (HuNoV) GI.1 and GII.4 by chlorine under conditions that mimic sewage treatment. Using a porcine gastric mucin-magnetic bead (PGM-MB) assay, no statistically significant loss in HuNoV binding (inactivation) was observed for secondary effluent ...

  2. Differences in the binding of human norovirus to and from Romaine lettuce and raspberries by water and electrolyzed waters

    USDA-ARS?s Scientific Manuscript database

    Noroviruses (NoV) annually cause millions of cases of gastrointestinal disease in the United States. Contamination of fresh produce with human NoV (hNoV) could occur through contamination in the field, by food handlers during harvest or packaging, or during processing. We assessed the effectivenes...

  3. In Situ CaptureRT-qPCR: A new simple and sensitive method to detect human norovirus in oysters

    USDA-ARS?s Scientific Manuscript database

    Human noroviruses (HuNoVs) are the major cause for the non-bacterial acute gastroenteritis worldwide. RT-qPCR is a widely used method to detect HuNoVs. However, the method is unable to discriminate between infectious and non-infectious viruses. Previously, we reported that the receptor mediated in s...

  4. Attachment and localization of human norovirus and animal caliciviruses in fresh produce.

    PubMed

    DiCaprio, Erin; Purgianto, Anastasia; Ma, Yuanmei; Hughes, John; Dai, Xiangjun; Li, Jianrong

    2015-10-15

    Fresh produce is a high risk food for human norovirus (NoV) contamination. To help control this pathogen in fresh produce, a better understanding of the interaction of human NoV and fresh produce needs to be established. In this study the attachment of human NoV and animal caliciviruses (murine norovirus, MNV-1; Tulane virus, TV) to fresh produce was evaluated, using both visualization and viral enumeration techniques. It was found that a human NoV GII.4 strain attached efficiently to the Romaine lettuce leaves and roots and green onion shoots, and that washing with PBS or 200 ppm of chlorine removed less than 0.4 log of viral RNA copies from the tissues. In contrast, TV and MNV-1 bound more efficiently to Romaine lettuce leaves than to the roots, and simple washing removed less than 1 log of viruses from the lettuce leaves and 1-4 log PFU of viruses from roots. Subsequently, the location of virus particles in fresh produce was visualized using a fluorescence-based Quantum Dots (Q-Dots) assay and confocal microscopy. It was found that human NoV virus-like particles (VLPs), TV, and MNV-1 associated with the surface of Romaine lettuce and were found aggregating in and around the stomata. In green onions, human NoV VLPs were found between the cells of the epidermis and cell walls of both the shoots and roots. However, TV and MNV-1 were found to be covering the surface of the epidermal cells in both the shoots and roots of green onions. Collectively, these results demonstrate that (i) washing with 200 ppm chlorine is ineffective in removing human NoV from fresh produce; and (ii) different viruses vary in their localization patterns to different varieties of fresh produce.

  5. Internalization and Dissemination of Human Norovirus and Animal Caliciviruses in Hydroponically Grown Romaine Lettuce

    PubMed Central

    DiCaprio, Erin; Ma, Yuanmei; Purgianto, Anastasia; Hughes, John

    2012-01-01

    Fresh produce is a major vehicle for the transmission of human norovirus (NoV) because it is easily contaminated during both pre- and postharvest stages. However, the ecology of human NoV in fresh produce is poorly understood. In this study, we determined whether human NoV and its surrogates can be internalized via roots and disseminated to edible portions of the plant. The roots of romaine lettuce growing in hydroponic feed water were inoculated with 1 × 106 RNA copies/ml of a human NoV genogroup II genotype 4 (GII.4) strain or 1 × 106 to 2 × 106 PFU/ml of animal caliciviruses (Tulane virus [TV] and murine norovirus [MNV-1]), and plants were allowed to grow for 2 weeks. Leaves, shoots, and roots were homogenized, and viral titers and/or RNA copies were determined by plaque assay and/or real-time reverse transcription (RT)-PCR. For human NoV, high levels of viral-genome RNA (105 to 106 RNA copies/g) were detected in leaves, shoots, and roots at day 1 postinoculation and remained stable over the 14-day study period. For MNV-1 and TV, relatively low levels of infectious virus particles (101 to 103 PFU/g) were detected in leaves and shoots at days 1 and 2 postinoculation, but virus reached a peak titer (105 to 106 PFU/g) at day 3 or 7 postinoculation. In addition, human NoV had a rate of internalization comparable with that of TV as determined by real-time RT-PCR, whereas TV was more efficiently internalized than MNV-1 as determined by plaque assay. Taken together, these results demonstrated that human NoV and animal caliciviruses became internalized via roots and efficiently disseminated to the shoots and leaves of the lettuce. PMID:22729543

  6. Nucleotidylylation of the VPg Protein of a Human Norovirus by its Proteinase-Polymerase Precursor Protein

    PubMed Central

    Belliot, Gaël; Sosnovtsev, Stanislav V.; Chang, Kyeong-Ok; McPhie, Peter; Green, Kim Y.

    2008-01-01

    Caliciviruses have a positive strand RNA genome covalently-linked at the 5’-end to a small protein, VPg. This study examined the biochemical modification of VPg by the ProPol form of the polymerase of human norovirus strain MD145 (GII.4). Recombinant norovirus VPg was shown to be nucleotidylylated in the presence of Mn2+ by MD145 ProPol. Phosphodiesterase I treatment of the nucleotidylylated VPg released the incorporated UMP, which was consistent with linkage of RNA to VPg via a phosphodiester bond. Mutagenesis analysis of VPg identified Tyrosine 27 as the target amino acid for this linkage, and suggested that VPg conformation was important for the reaction. Nucleotidylylation was inefficient in the presence of Mg2+; however the addition of full- and subgenomic-length MD145 RNA transcripts led to a marked enhancement of the nucleotidylylation efficiency in the presence of this divalent cation. Furthermore, evidence was found for the presence of an RNA element near the 3’-end of the polyadenylated genome that enhanced the efficiency of nucleotidylylation in the presence of Mg2+. PMID:18234264

  7. Nucleotidylylation of the VPg protein of a human norovirus by its proteinase-polymerase precursor protein.

    PubMed

    Belliot, Gaël; Sosnovtsev, Stanislav V; Chang, Kyeong-Ok; McPhie, Peter; Green, Kim Y

    2008-04-25

    Caliciviruses have a positive strand RNA genome covalently-linked at the 5'-end to a small protein, VPg. This study examined the biochemical modification of VPg by the ProPol form of the polymerase of human norovirus strain MD145 (GII.4). Recombinant norovirus VPg was shown to be nucleotidylylated in the presence of Mn2+ by MD145 ProPol. Phosphodiesterase I treatment of the nucleotidylylated VPg released the incorporated UMP, which was consistent with linkage of RNA to VPg via a phosphodiester bond. Mutagenesis analysis of VPg identified Tyrosine 27 as the target amino acid for this linkage, and suggested that VPg conformation was important for the reaction. Nucleotidylylation was inefficient in the presence of Mg2+; however the addition of full- and subgenomic-length MD145 RNA transcripts led to a marked enhancement of the nucleotidylylation efficiency in the presence of this divalent cation. Furthermore, evidence was found for the presence of an RNA element near the 3'-end of the polyadenylated genome that enhanced the efficiency of nucleotidylylation in the presence of Mg2+.

  8. Abiotic Stress and Phyllosphere Bacteria Influence the Survival of Human Norovirus and Its Surrogates on Preharvest Leafy Greens

    PubMed Central

    Esseili, Malak A.; Gao, Xiang; Tegtmeier, Sarah; Saif, Linda J.

    2015-01-01

    Foodborne outbreaks of human noroviruses (HuNoVs) are frequently associated with leafy greens. Because there is no effective method to eliminate HuNoV from postharvest leafy greens, understanding virus survival under preharvest conditions is crucial. The objective of this study was to evaluate the survival of HuNoV and its surrogate viruses, murine norovirus (MNV), porcine sapovirus (SaV), and Tulane virus (TV), on preharvest lettuce and spinach that were subjected to abiotic stress (physical damage, heat, or flood). We also examined the bacteria culturable from the phyllosphere in response to abiotic stress and in relation to viral persistence. Mature plants were subjected to stressors 2 days prior to inoculation of the viruses on leaves. We quantified the viral RNA, determined the infectivity of the surrogates, and performed bacterial counts on postinoculation days (PIDs) 0, 1, 7, and 14. For both plant types, time exerted significant effects on HuNoV, MNV, SaV, and TV RNA titers, with greater effects being seen for the surrogates. Infectious surrogate viruses were undetectable on PID 14. Only physical damage on PID 14 significantly enhanced HuNoV RNA persistence on lettuce, while the three stressors differentially enhanced the persistence of MNV and TV RNA. Bacterial counts were significantly affected by time and plant type but not by the stressors. However, bacterial counts correlated significantly with HuNoV RNA titers on spinach and with the presence of surrogate viruses on both plant types under various conditions. In conclusion, abiotic stressors and phyllosphere bacterial density may differentially influence the survival of HuNoV and its surrogates on lettuce and spinach, emphasizing the need for the use of preventive measures at the preharvest stage. PMID:26497461

  9. Abiotic Stress and Phyllosphere Bacteria Influence the Survival of Human Norovirus and Its Surrogates on Preharvest Leafy Greens.

    PubMed

    Esseili, Malak A; Gao, Xiang; Tegtmeier, Sarah; Saif, Linda J; Wang, Qiuhong

    2015-10-23

    Foodborne outbreaks of human noroviruses (HuNoVs) are frequently associated with leafy greens. Because there is no effective method to eliminate HuNoV from postharvest leafy greens, understanding virus survival under preharvest conditions is crucial. The objective of this study was to evaluate the survival of HuNoV and its surrogate viruses, murine norovirus (MNV), porcine sapovirus (SaV), and Tulane virus (TV), on preharvest lettuce and spinach that were subjected to abiotic stress (physical damage, heat, or flood). We also examined the bacteria culturable from the phyllosphere in response to abiotic stress and in relation to viral persistence. Mature plants were subjected to stressors 2 days prior to inoculation of the viruses on leaves. We quantified the viral RNA, determined the infectivity of the surrogates, and performed bacterial counts on postinoculation days (PIDs) 0, 1, 7, and 14. For both plant types, time exerted significant effects on HuNoV, MNV, SaV, and TV RNA titers, with greater effects being seen for the surrogates. Infectious surrogate viruses were undetectable on PID 14. Only physical damage on PID 14 significantly enhanced HuNoV RNA persistence on lettuce, while the three stressors differentially enhanced the persistence of MNV and TV RNA. Bacterial counts were significantly affected by time and plant type but not by the stressors. However, bacterial counts correlated significantly with HuNoV RNA titers on spinach and with the presence of surrogate viruses on both plant types under various conditions. In conclusion, abiotic stressors and phyllosphere bacterial density may differentially influence the survival of HuNoV and its surrogates on lettuce and spinach, emphasizing the need for the use of preventive measures at the preharvest stage.

  10. Antiviral Activity of Gold/Copper Sulfide Core/Shell Nanoparticles against Human Norovirus Virus-Like Particles.

    PubMed

    Broglie, Jessica Jenkins; Alston, Brittny; Yang, Chang; Ma, Lun; Adcock, Audrey F; Chen, Wei; Yang, Liju

    2015-01-01

    Human norovirus is a leading cause of acute gastroenteritis worldwide in a plethora of residential and commercial settings, including restaurants, schools, and hospitals. Methods for easily detecting the virus and for treating and preventing infection are critical to stopping norovirus outbreaks, and inactivation via nanoparticles (NPs) is a more universal and attractive alternative to other physical and chemical approaches. Using norovirus GI.1 (Norwalk) virus-like particles (VLPs) as a model viral system, this study characterized the antiviral activity of Au/CuS core/shell nanoparticles (NPs) against GI.1 VLPs for the rapid inactivation of HuNoV. Inactivation of VLPs (GI.1) by Au/CuS NPs evaluated using an absorbance-based ELISA indicated that treatment with 0.083 μM NPs for 10 min inactivated ~50% VLPs in a 0.37 μg/ml VLP solution and 0.83 μM NPs for 10 min completely inactivated the VLPs. Increasing nanoparticle concentration and/or VLP-NP contact time significantly increased the virucidal efficacy of Au/CuS NPs. Changes to the VLP particle morphology, size, and capsid protein were characterized using dynamic light scattering, transmission electron microscopy, and Western blot analysis. The strategy reported here provides the first reported proof-of-concept Au/CuS NPs-based virucide for rapidly inactivating human norovirus.

  11. Antiviral Activity of Gold/Copper Sulfide Core/Shell Nanoparticles against Human Norovirus Virus-Like Particles

    PubMed Central

    Broglie, Jessica Jenkins; Alston, Brittny; Yang, Chang; Ma, Lun; Adcock, Audrey F.; Chen, Wei; Yang, Liju

    2015-01-01

    Human norovirus is a leading cause of acute gastroenteritis worldwide in a plethora of residential and commercial settings, including restaurants, schools, and hospitals. Methods for easily detecting the virus and for treating and preventing infection are critical to stopping norovirus outbreaks, and inactivation via nanoparticles (NPs) is a more universal and attractive alternative to other physical and chemical approaches. Using norovirus GI.1 (Norwalk) virus-like particles (VLPs) as a model viral system, this study characterized the antiviral activity of Au/CuS core/shell nanoparticles (NPs) against GI.1 VLPs for the rapid inactivation of HuNoV. Inactivation of VLPs (GI.1) by Au/CuS NPs evaluated using an absorbance-based ELISA indicated that treatment with 0.083 μM NPs for 10 min inactivated ~50% VLPs in a 0.37 μg/ml VLP solution and 0.83 μM NPs for 10 min completely inactivated the VLPs. Increasing nanoparticle concentration and/or VLP-NP contact time significantly increased the virucidal efficacy of Au/CuS NPs. Changes to the VLP particle morphology, size, and capsid protein were characterized using dynamic light scattering, transmission electron microscopy, and Western blot analysis. The strategy reported here provides the first reported proof-of-concept Au/CuS NPs-based virucide for rapidly inactivating human norovirus. PMID:26474396

  12. Assessment of Functional Norovirus Antibody Responses by Blocking Assay in Mice.

    PubMed

    Malm, Maria; Tamminen, Kirsi; Blazevic, Vesna

    2016-01-01

    Norovirus (NoV)-specific serum antibodies bind to NoV-derived virus-like particles (VLPs) and block the binding of VLPs to the host cell attachment factors/receptors, histo-blood group antigens (HBGAs). Blocking antibodies in human sera have been associated with a protection from NoV infection and disease. Studies of experimental NoV VLP-based vaccines measure blocking antibodies in animal sera instead of a traditional virus neutralization assay. This chapter describes the methodology for analyzing blocking antibodies from NoV GII.4 VLP-immunized mouse sera. Protocol for obtaining mouse NoV GII.4-specific immune sera is described, followed by the detailed protocol for blocking assay using synthetic HBGAs.

  13. Molecular epidemiology of norovirus in South Korea.

    PubMed

    Lee, Sung-Geun; Cho, Han-Gil; Paik, Soon-Young

    2015-02-01

    Norovirus is a major cause of viral gastroenteritis and a common cause of foodborne and waterborne outbreaks. Norovirus outbreaks are responsible for economic losses, most notably to the public health and food industry field. Norovirus has characteristics such as low infectious dose, prolonged shedding period, strong stability, great diversity, and frequent genome mutations. Besides these characteristics, they are known for rapid and extensive spread in closed settings such as hospitals, hotels, and schools. Norovirus is well known as a major agent of food-poisoning in diverse settings in South Korea. For these reasons, nationwide surveillance for norovirus is active in both clinical and environmental settings in South Korea. Recent studies have reported the emergence of variants and novel recombinants of norovirus. In this review, we summarized studies on the molecular epidemiology and nationwide surveillance of norovirus in South Korea. This review will provide information for vaccine development and prediction of new emerging variants of norovirus in South Korea.

  14. Epidemiology of Rotavirus-Norovirus Co-Infection and Determination of Norovirus Genogrouping among Children with Acute Gastroenteritis in Tehran, Iran

    PubMed Central

    Nasab, Seyed Dawood Mousavi; Sabahi, Farzaneh; Makvandi, Manoochehr; Samiee, Siamak Mirab; Nadji, Seyed Alireza; Ravanshad, Mehrdad

    2016-01-01

    Background: Enteric viruses, particularly human rotavirus and norovirus, have been shown to replace bacteria and parasites, as the most common pathogens responsible for acute diarrhea. However, there are still few epidemiological data on the simultaneous occurrence of these viruses in Iran. In this regard, the aim of this study was to assess the useful epidemiological data on the gastroenteritis associated with rotavirus-norovirus mixed infection and to examine the prevalence of norovirus genogrouping among children aged less than five years old in Iran. Methods: A total of 170 stool samples were collected from children under five years of age with the clinical signs and symptoms of acute gastroenteritis, from May 2013 to May 2014. For the detection of both rotavirus and norovirus, total RNA was extracted from all samples, followed by reverse transcription polymerase chain reaction (RT-PCR). For both detected rotaviruses and noroviruses, genogrouping was performed. Results: Of 170 samples, 49 (28.8%) and 15 (8.8%) samples were found to be positive for rotavirus and norovirus infections by RT-PCR. Interestingly, 6 (3.5%) patients were positive for both infections. Among the 15 norovirus-positive patients, 13 (86.6%) and 2 (13.3%) belonged to genogroups GII and GI. Conclusion: The norovirus genogroup GII and rotavirus lead to the serious infections in children with acute gastroenteritis. However, more well-designed studies are needed to further elucidate the role of other enteric viruses in acute gastroenteritis PMID:27137790

  15. Blueberry proanthocyanidins against human norovirus surrogates in model foods and under simulated gastric conditions.

    PubMed

    Joshi, Snehal; Howell, Amy B; D'Souza, Doris H

    2017-05-01

    Blueberry proanthocyanidins (B-PAC) are known to decrease titers of human norovirus surrogates in vitro. The application of B-PAC as therapeutic or preventive options against foodborne viral illness needs to be determined using model foods and simulated gastric conditions in vitro. The objective of this study was to evaluate the antiviral effect of B-PAC in model foods (apple juice (AJ) and 2% reduced fat milk) and simulated gastrointestinal fluids against cultivable human norovirus surrogates (feline calicivirus; FCV-F9 and murine norovirus; MNV-1) over 24 h at 37 °C. Equal amounts of each virus (5 log PFU/ml) was mixed with B-PAC (1, 2 and 5 mg/ml) prepared either in AJ, or 2% milk, or simulated gastric fluids and incubated over 24 h at 37 °C. Controls included phosphate buffered saline, malic acid (pH 7.2), AJ, 2% milk or simulated gastric and intestinal fluids incubated with virus over 24 h at 37 °C. The tested viruses were reduced to undetectable levels within 15 min with B-PAC (1, 2 and 5 mg/ml) in AJ (pH 3.6). However, antiviral activity of B-PAC was reduced in milk. FCV-F9 was reduced by 0.4 and 1.09 log PFU/ml with 2 and 5 mg/ml B-PAC in milk, respectively and MNV-1 titers were reduced by 0.81 log PFU/ml with 5 mg/ml B-PAC in milk after 24 h. B-PAC at 5 mg/ml in simulated intestinal fluid reduced titers of the tested viruses to undetectable levels within 30 min. Overall, these results show the potential of B-PAC as preventive and therapeutic options for foodborne viral illnesses. Copyright © 2016. Published by Elsevier Ltd.

  16. Norovirus Symptoms

    MedlinePlus

    ... Norovirus Infection, National Institutes of Health NoroCORE Food Virology Symptoms Language: English Español (Spanish) Recommend on Facebook ... Norovirus Infection, National Institutes of Health NoroCORE Food Virology Language: English Español (Spanish) File Formats Help: How ...

  17. Norovirus Treatment

    MedlinePlus

    ... Norovirus Infection, National Institutes of Health NoroCORE Food Virology Treatment Language: English Español (Spanish) Recommend on Facebook ... Norovirus Infection, National Institutes of Health NoroCORE Food Virology Language: English Español (Spanish) File Formats Help: How ...

  18. Efficacy of common disinfectant/cleaning agents in inactivating murine norovirus and feline calicivirus as surrogate viruses for human norovirus.

    PubMed

    Chiu, Stephanie; Skura, Brenton; Petric, Martin; McIntyre, Lorraine; Gamage, Bruce; Isaac-Renton, Judith

    2015-11-01

    The efficacies of disinfection by sodium hypochlorite, accelerated hydrogen peroxide (AHP), and quaternary ammonium compound (QUAT) commonly used in health care facilities were determined using the surrogate viruses murine norovirus (MNV-1) and feline calicivirus (FCV). A virus suspension of known concentration (with or without a soil load) was deposited onto stainless steel discs under wet or dry load conditions and exposed to defined concentrations of the disinfectant/cleaning agent for 1-, 5-, or 10-minute contact time using the quantitative carrier test (QCT-2) method. Virus inactivation was determined by plaque assay. At an exposure time of 1 minute, sodium hypochlorite at 2,700 ppm was able to inactivate MNV-1 and FCV with a >5 log10 reduction. After 10 minutes, MNV-1 was inactivated by AHP at 35,000 ppm, whereas FCV was inactivated at 3,500 ppm. MNV-1 was not inactivated by QUAT at 2,800 ppm. A QUAT-alcohol formulation containing 2,000 ppm QUAT and 70% ethanol was effective in inactivating MNV-1 after 5 minutes, but resulted in only a <3 log10 reduction of FCV after 10 minutes. AHP and QUAT products were less effective than sodium hypochlorite for the inactivation of MNV-1 and FCV. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  19. Human norovirus transfer to stainless steel and small fruits during handling.

    PubMed

    Sharps, Christopher P; Kotwal, Grishma; Cannon, Jennifer L

    2012-08-01

    Human noroviruses (NoVs) cause an estimated 58% of foodborne illnesses in the United States annually. The majority of these outbreaks are due to contamination by food handlers. The objective of this study was to quantify the transfer rate and degree of contamination that occurs on small fruits (blueberries, grapes, and raspberries) and food contact surfaces (stainless steel) when manipulated with NoV-contaminated hands. Human NoVs (genogroups I and II [GI and GII]) and murine norovirus (MNV-1) were inoculated individually or as a three-virus cocktail onto donor surfaces (gloved fingertips or stainless steel) and either immediately interfaced with one or more recipient surfaces (fruit, gloves, or stainless steel) or allowed to dry before contact. Viruses on recipient surfaces were quantified by real-time quantitative reverse transcriptase PCR. Transfer rates were 58 to 60% for GII NoV from fingertips to stainless steel, blueberries, and grapes and 4% for raspberries under wet conditions. Dry transfer occurred at a much lower rate (<1%) for all recipient surfaces. Transfer rates ranged from 20 to 70% from fingertips to stainless steel or fruits for the GI, GII, and MNV-1 virus cocktail under wet conditions and from 4 to 12% for all viruses under dry transfer conditions. Fomite transfer (from stainless steel to fingertip and then to fruit) was lower for all viruses, ranging from 1 to 50% for wet transfer and 2 to 11% for dry transfer. Viruses transferred at higher rates under wet conditions than under dry conditions. The inoculum matrix affected the rate of virus transfer, but the majority of experiments resulted in no difference in the transfer rates for the three viruses. While transfer rates were often low, the amount of virus transferred to recipient surfaces often exceeded 4- or 5-log genomic copy numbers, indicating a potential food safety hazard. Quantitative data such as these are needed to model scenarios of produce contamination by food handling and devise

  20. Seroprevalence of Norovirus Genogroup IV Antibodies among Humans, Italy, 2010–2011

    PubMed Central

    Di Profio, Federica; Ceci, Chiara; Di Felice, Elisabetta; Green, Kim Y.; Bok, Karin; De Grazia, Simona; Giammanco, Giovanni M.; Massirio, Ivano; Lorusso, Eleonora; Buonavoglia, Canio; Marsilio, Fulvio; Martella, Vito

    2014-01-01

    Noroviruses (NoVs) of genogroup IV (GIV) (Alphatron-like) cause infections in humans and in carnivorous animals such as dogs and cats. We screened an age-stratified collection of serum samples from 535 humans in Italy, using virus-like particles of genotypes GIV.1, circulating in humans, and GIV.2, identified in animals, in ELISA, in order to investigate the prevalence of GIV NoV-specific IgG antibodies. Antibodies specific for both genotypes were detected, ranging from a prevalence of 6.6% to 44.8% for GIV.1 and from 6.8% to 15.1% for GIV.2 among different age groups. These data are consistent with a higher prevalence of GIV.1 strains in the human population. Analysis of antibodies against GIV.2 suggests zoonotic transmission of animal NoVs, likely attributable to interaction between humans and domestic pets. This finding, and recent documentation of human transmission of NoVs to dogs, indicate the possibility of an evolutionary relationship between human and animal NoVs. PMID:25340375

  1. Human norovirus surrogate reduction in milk and juice blends by high pressure homogenization.

    PubMed

    Horm, Katie Marie; Harte, Federico Miguel; D'Souza, Doris Helen

    2012-11-01

    Novel processing technologies such as high pressure homogenization (HPH) for the inactivation of foodborne viruses in fluids that retain nutritional attributes are in high demand. The objectives of this research were (i) to determine the effects of HPH alone or with an emulsifier (lecithin) on human norovirus surrogates-murine norovirus (MNV-1) and feline calicivirus (FCV-F9)-in skim milk and orange juice, and (ii) to determine HPH effects on FCV-F9 and MNV-1 in orange and pomegranate juice blends. Experiments were conducted in duplicate at 0, 100, 200, 250, and 300 MPa for <2 s and plaque was assayed in duplicate. In milk, FCV-F9 was reduced by ≥4 and ∼1.3 log PFU/ml at 300 and 250 MPa, respectively, and ≥4- and ∼1-log PFU/ml reductions were obtained in orange juice at 300 and 250 MPa, respectively. In orange juice or milk combined with lecithin, FCV-F9 was reduced to nondetectable levels at 300 MPa, and by 1.77 and 0.78 log PFU/ml at 250 MPa. MNV-1 in milk was reduced by ∼1.3 log PFU/ml only at 300 MPa, and by ∼0.8 and ∼0.4 log PFU/ml in orange juice at 300 and 250 MPa, respectively. MNV-1 in milk or orange juice containing lecithin at 300 MPa showed 1.32- and 2.5-log PFU/ml reductions, respectively. In the pomegranate-orange juice blend, FCV-F9 was completely reduced, and MNV-1 was reduced by 1.04 and 1.78 log PFU/ml at 250 and 300 MPa, respectively. These results show that HPH has potential for commercial use to inactivate foodborne virus surrogates in juices.

  2. Aqueous Extracts of Hibiscus sabdariffa Calyces Decrease Hepatitis A Virus and Human Norovirus Surrogate Titers.

    PubMed

    Joshi, Snehal S; Dice, Lezlee; D'Souza, Doris H

    2015-12-01

    Hibiscus sabdariffa extract is known to have antioxidant, anti-diabetic, and antimicrobial properties. However, their effects against foodborne viruses are currently unknown. The objective of this study was to determine the antiviral effects of aqueous extracts of H. sabdariffa against human norovirus surrogates (feline calicivirus (FCV-F9) and murine norovirus (MNV-1)) and hepatitis A virus (HAV) at 37 °C over 24 h. Individual viruses (~5 log PFU/ml) were incubated with 40 or 100 mg/ml of aqueous hibiscus extract (HE; pH 3.6), protocatechuic acid (PCA; 3 or 6 mg/ml, pH 3.6), ferulic acid (FA; 0.5 or 1 mg/ml; pH 4.0), malic acid (10 mM; pH 3.0), or phosphate buffered saline (pH 7.2 as control) at 37 °C over 24 h. Each treatment was replicated thrice and plaque assayed in duplicate. FCV-F9 titers were reduced to undetectable levels after 15 min with both 40 and 100 mg/ml HE. MNV-1 was reduced by 1.77 ± 0.10 and 1.88 ± 0.12 log PFU/ml after 6 h with 40 and 100 mg/ml HE, respectively, and to undetectable levels after 24 h by both concentrations. HAV was reduced to undetectable levels by both HE concentrations after 24 h. PCA at 3 mg/ml reduced FCV-F9 titers to undetectable levels after 6 h, MNV-1 by 0.53 ± 0.01 log PFU/ml after 6 h, and caused no significant change in HAV titers. FA reduced FCV-F9 to undetectable levels after 3 h and MNV-1 and HAV after 24 h. Transmission electron microscopy showed no conclusive results. The findings suggest that H. sabdariffa extracts have potential to prevent foodborne viral transmission.

  3. Self-assembly of the recombinant capsid protein of a bovine norovirus (BoNV) into virus-like particles and evaluation of cross-reactivity of BoNV with human noroviruses.

    PubMed

    Han, M G; Wang, Q; Smiley, J R; Chang, K O; Saif, L J

    2005-02-01

    None of the enteric caliciviruses except Po/Sapo/GIII/Cowden/80/US replicates in cell culture, which complicates efforts to develop control strategies or to study viral replication. To develop serological assays for bovine noroviruses (BoNVs) and to determine the cross-reactivity of BoNV with human noroviruses, we generated two recombinant baculoviruses, rCV186-OH and rJNCV, to express the capsid genes of Bo/CV186-OH/00/US (Norovirus genogroup III [GIII], genotype 2 [GIII/2]). rCV186-OH expressed the expected 57-kDa capsid protein, but rJNCV expressed a truncated capsid protein of 35 kDa. Sequence analysis of rJNCV identified a single nucleotide deletion in the P domain of the capsid gene, which introduced a stop codon at amino acid 323. The recombinant capsid protein produced by rCV186-OH but not that produced by rJNCV self-assembled into virus-like particles (VLPs) similar to native BoNV. An antibody-capture enzyme-linked immunosorbent assay (ELISA) and antigen-capture ELISA (Ag-ELISA) detected serum antibody and antigen, respectively, from calves infected with Bo/CV186-OH/00/US but not antibodies or antigens to other enteric viruses. In other tests of the GIII/2 BoNV Ag-ELISA, no cross-reactivity was observed with VLPs from one GI and four GII human noroviruses and porcine sapovirus Cowden strain. Because, like human noroviruses, BoNVs do not grow in cell culture, the BoNV VLPs will be useful in the serological assays described for the detection of BoNV antibody and antigen. Consistent with the phylogenetic analysis of the capsid genes of bovine and human noroviruses (M. G. Han, J. R. Smiley, C. Thomas, and L. J. Saif, J. Clin. Microbiol. 42:5214-5224, 2004), the results suggest that GIII/2 BoNV does not share significant antigenic relationships with the five characterized human noroviruses tested.

  4. Infection control for norovirus

    PubMed Central

    Barclay, L.; Park, G. W.; Vega, E.; Hall, A.; Parashar, U.; Vinjé, J.; Lopman, B.

    2015-01-01

    Norovirus infections are notoriously difficult to prevent and control, owing to their low infectious dose, high shedding titre, and environmental stability. The virus can spread through multiple transmission routes, of which person-to-person and foodborne are the most important. Recent advances in molecular diagnostics have helped to establish norovirus as the most common cause of sporadic gastroenteritis and the most common cause of outbreaks of acute gastroenteritis across all ages. In this article, we review the epidemiology and virology of noroviruses, and prevention and control guidelines, with a focus on the principles of disinfection and decontamination. Outbreak management relies on sound infection control principles, including hand hygiene, limiting exposure to infectious individuals, and thorough environmental decontamination. Ideally, all infection control recommendations would rely on empirical evidence, but a number of challenges, including the inability to culture noroviruses in the laboratory and the challenges of outbreak management in complex environments, has made it difficult to garner clear evidence of efficacy in certain areas of infection control. New experimental data on cultivable surrogates for human norovirus and on environmental survivability and relative resistance to commonly used disinfectants are providing new insights for further refinining disinfection practices. Finally, clinical trials are underway to evaluate the efficacy of vaccines, which may shift the current infection control principles to more targeted interventions. PMID:24813073

  5. Norovirus Infections

    MedlinePlus

    Noroviruses are a group of related viruses. Infection with these viruses causes an illness called gastroenteritis, an inflammation of the stomach and intestines. It can spread from person to person, or ...

  6. A systematic review of human norovirus survival reveals a greater persistence of human norovirus RT-qPCR signals compared to those of cultivable surrogate viruses.

    PubMed

    Knight, Angus; Haines, John; Stals, Ambroos; Li, Dan; Uyttendaele, Mieke; Knight, Alastair; Jaykus, Lee-Ann

    2016-01-04

    Human noroviruses (hNoV) are the single largest cause of acute gastroenteritis in the western world. The efficacy of hNoV control measures remains largely unknown, partly owing to the inability to grow the virus in vitro and partly to the large number of surrogate studies of unknown relevance. A systematic review of the persistence and survival of hNoV in foods and the environment was undertaken based upon PRISMA (preferred reporting items for systematic reviews and meta analyses) guidelines to answer the questions: (1) "What are the natural hNoV persistence characteristics in food and the environment?" and (2) "How can these properties be altered by applying physical and/or chemical treatments to foods or food contact surfaces?" Over 10,000 citations were screened using defined inclusion and exclusion criteria. One hundred and twenty-six (126) citations were identified for further evaluation and data were extracted based upon the conditions of study and treatment (e.g., treatment parameters, pH, and temperature, time, infectivity, and RT-qPCR results). Since the only markers for hNoV persistence and survival were RT-qPCR data and human challenge studies, citations for further analysis were restricted to only those that included data on hNoV behavior (using RT-qPCR) as compared directly to surrogate virus behavior (using both RT-qPCR and infectivity) in the same study, and clinical studies. Based on these criteria, a total of 12 independent studies (5 for thermal inactivation and 7 for available chlorine) and 3 human challenge studies were identified. RT-qPCR always underestimated reductions in surrogate virus titre as a function of treatment when compared to infectivity. The corresponding reductions in RT-qPCR signals for hNoV under comparable conditions were nearly always less than those observed for the surrogates. These relationships were statistically significant for heat when comparing persistence of hNoV RT-qPCR signals with surrogate MNV-1 RT-qPCR signals

  7. Prevailing Sydney like Norovirus GII.4 VLPs induce systemic and mucosal immune responses in mice.

    PubMed

    Huo, Yuqi; Wan, Xin; Ling, Tong; Wu, Jie; Wang, Zejun; Meng, Shengli; Shen, Shuo

    2015-12-01

    The newly emerged Norovirus (NoV) Sydney 2012 strain has been sweeping all over the world, causing acute non-bacterial gastroenteritis in adults and children. Due to a lack of cell culture system, virus like particles (VLPs) has been assembled and used as vaccine candidates in preclinical and clinical studies. Expression of the major capsid protein of NoVs using recombinant baculovirus expression system in Sf9 cells leads to formation of VLPs that are morphologically and antigenically similar to true virions. In this study, VLPs were successfully produced using the VP1 of Sydney-2012-like strain and its immunogenicity was evaluated by different routes and its capability in inducing mucosal immune responses in the presence and absence of adjuvants in BALB/c mice. Administration of NoV VLPs in the presence of Al(OH)3 or monophosphoryl lipid A (MPL-A) led to high titers of VLP-specific IgG antibodies. Administration of VLPs orally in the presence of cholera toxin subunit B (CTB) didn't enhance mucosal immune response as less fecal IgA positive mice were observed when compared with those given VLPs only. Our study represents the first immunogenicity study of VLPs derived from current pandemic Sydney 2012 strain and which might have implications in the development of NoVs vaccine in china.

  8. High sensitive and selective electrochemical biosensor: Label-free detection of human norovirus using affinity peptide as molecular binder.

    PubMed

    Hwang, Hye Jin; Ryu, Myung Yi; Park, Chan Young; Ahn, Junki; Park, Hyun Gyu; Choi, Changsun; Ha, Sang-Do; Park, Tae Jung; Park, Jong Pil

    2017-01-15

    Norovirus is known as the major cause of highly infection for gastrointestinal tracts. In this study, robust and highly sensitive biosensors for detecting human norovirus by employing a recognition affinity peptide-based electrochemical platform were described. A series of amino acid-substituted and cysteine-incorporated recognition peptides isolated from evolutionary phage display technique was chemically synthesized and immobilized to a gold sensor layer, the detection performance of the gold-immobilized synthetic peptide-based sensor system was assessed using QCM, CV and EIS. Using EIS, the limit of detection with Noro-1 as a molecular binder was found to be 99.8nM for recombinant noroviral capsid proteins (rP2) and 7.8copies/mL for human norovirus, thereby demonstrating a high degree of sensitivity for their corresponding targets. These results suggest that a biosensor which consists of affinity peptides as a molecular binder and miniaturized microdevices as diagnostic tool could be served as a new type of biosensing platform for point-of-care testing.

  9. Complete Genome Sequence of Human Norovirus GII.4_2006b, a Variant of Minerva 2006.

    PubMed

    Yang, Zhihui; Mammel, Mark K; Kulka, Michael

    2016-01-28

    In 2006, the National Calicivirus Laboratory at the U.S. Centers for Disease Control and Prevention (CDC) confirmed multistate outbreaks of norovirus infection and identified two new GII.4 norovirus strains (Minerva and Laurens) through partial sequencing of the major capsid (VP1) gene. Here, we report the first complete genome sequence of the GII.4 Minerva isolate. Copyright © 2016 Yang et al.

  10. Bacterial histo-blood group antigens contributing to genotype-dependent removal of human noroviruses with a microfiltration membrane.

    PubMed

    Amarasiri, Mohan; Hashiba, Satoshi; Miura, Takayuki; Nakagomi, Toyoko; Nakagomi, Osamu; Ishii, Satoshi; Okabe, Satoshi; Sano, Daisuke

    2016-05-15

    We demonstrated the genotype-dependent removal of human norovirus particles with a microfiltration (MF) membrane in the presence of bacteria bearing histo-blood group antigens (HBGAs). Three genotypes (GII.3, GII.4, and GII.6) of norovirus-like particles (NoVLPs) were mixed with three bacterial strains (Enterobacter sp. SENG-6, Escherichia coli O86:K61:B7, and Staphylococcus epidermidis), respectively, and the mixture was filtered with an MF membrane having a nominal pore size of 0.45 μm. All NoVLP genotypes were rejected by the MF membrane in the presence of Enterobacter sp. SENG-6, which excreted HBGAs as extracellular polymeric substances (EPS). This MF membrane removal of NoVLPs was not significant when EPS was removed from cells of Enterobacter sp. SENG-6. GII.6 NoVLP was not rejected with the MF membrane in the presence of E. coli O86:K61:B7, but the removal of EPS of E. coli O86:K61:B7 increased the removal efficiency due to the interaction of NoVLPs with the exposed B-antigen in lipopolysaccharide (LPS) of E. coli O86:K61:B7. No MF membrane removal of all three genotypes was observed when S. epidermidis, an HBGA-negative strain, was mixed with NoVLPs. These results demonstrate that the location of HBGAs on bacterial cells is an important factor in determining the genotype-dependent removal efficiency of norovirus particles with the MF membrane. The presence of HBGAs in mixed liquor suspended solids from a membrane bioreactor (MBR) pilot plant was confirmed by immune-transmission electron microscopy, which implies that bacterial HBGAs can contribute to the genotype-dependent removal of human noroviruses with MBR using MF membrane.

  11. Inactivation of the Tulane Virus, a Novel Surrogate for the Human Norovirus

    PubMed Central

    TIAN, PENG; YANG, DAVID; QUIGLEY, CHRISTINA; CHOU, MARISSA; JIANG, XI

    2014-01-01

    Human noroviruses (HuNoVs) are the major cause of nonbacterial gastroenteritis epidemics. The culturable feline calicivirus and murine norovirus have been used extensively as surrogates to study HuNoV biology, as HuNoV does not grow in vitro. Additional efforts to identify new surrogates are needed, because neither of these common surrogates are truly intestinal pathogens. The newly described Tulane virus (TV) is a typical calicivirus, it is isolated from macaque stools, is cultivable in vitro, and recognizes human histo-blood group antigens. Therefore, TV is a promising surrogate for HuNoVs. In this study, we evaluated the resistance or stability of TV under various physical and environmental conditions by measuring a 50% reduction of tissue culture infective dose (TCID50) by using a TV cell culture system. Due to the nature of this virus, it is hard to produce a high-titer stock through tissue culture. In our study, the maximal reduction in virus titers was 5 D (D = 1 log) in heat-denaturation and EtOH experiments, and 4 D in UV, chlorine, and pH-stability experiments. Therefore in this study, we defined the inactivation of TV as reaching a TCID50/ml of 0 (a 4- to 5-D reduction in TCID50, depending on the detection limit). TV was inactivated after incubation at 63°C for 5 min, incubation at 56°C for 30 min (5 D), exposure to 60 mJ/cm2 of UVC radiation (4 D), or incubation at 300 ppm of free chlorine for 10 min (4 D). TV was shown to be stable from pH 3.0 to 8.0, though an obvious reduction in virus titer was observed at pH 2.5 and 9.0, and was inactivated at pH 10.0 (4 D). TV was resistant to a low concentration of EtOH (40% or lower) but was fully inactivated (5 D) by 50 to 70% EtOH after a short exposure (20 s). In contrast, quantitative real-time PCR was unable to detect, or poorly detected, virus titer reductions between treated and untreated samples described in this study. PMID:23575140

  12. Characterization and inhibition of norovirus proteases of genogroups I and II using a fluorescence resonance energy transfer assay

    SciTech Connect

    Chang, Kyeong-Ok; Takahashi, Daisuke; Prakash, Om; Kim, Yunjeong

    2012-02-20

    Noroviruses are the major cause of food- or water-borne gastroenteritis outbreaks in humans. The norovirus protease that cleaves a large viral polyprotein to nonstructural proteins is essential for virus replication and an attractive target for antiviral drug development. Noroviruses show high genetic diversity with at least five genogroups, GI-GV, of which GI and GII are responsible for the majority of norovirus infections in humans. We cloned and expressed proteases of Norwalk virus (GI) and MD145 virus (GII) and characterized the enzymatic activities with fluorescence resonance energy transfer substrates. We demonstrated that the GI and GII proteases cleaved the substrates derived from the naturally occurring cleavage site in the open reading frame (ORF) 1 of G1 norovirus with similar efficiency, and that enzymatic activity of both proteases was inhibited by commercial protease inhibitors including chymostatin. The interaction of chymostatin to Norwalk virus protease was validated by nuclear magnetic resonance (NMR) spectroscopy.

  13. Variable High-Pressure-Processing Sensitivities for Genogroup II Human Noroviruses

    PubMed Central

    Lou, Fangfei; DiCaprio, Erin; Li, Xinhui; Dai, Xianjun; Ma, Yuanmei; Hughes, John; Chen, Haiqiang; Kingsley, David H.

    2016-01-01

    ABSTRACT Human norovirus (HuNoV) is a leading cause of foodborne diseases worldwide. High-pressure processing (HPP) is one of the most promising nonthermal technologies for the decontamination of viral pathogens in foods. However, the survival of HuNoVs after HPP is poorly understood because these viruses cannot be propagated in vitro. In this study, we estimated the survival of different HuNoV strains within genogroup II (GII) after HPP treatment using viral receptor-binding ability as an indicator. Four HuNoV strains (one GII genotype 1 [GII.1] strain, two GII.4 strains, and one GII.6 strain) were treated at high pressures ranging from 200 to 600 MPa. After treatment, the intact viral particles were captured by porcine gastric mucin-conjugated magnetic beads (PGM-MBs) that contained histo-blood group antigens, the functional receptors for HuNoVs. The genomic RNA copies of the captured HuNoVs were quantified by real-time reverse transcriptase PCR (RT-PCR). Two GII.4 HuNoVs had similar sensitivities to HPP. The resistance of HuNoV strains against HPP ranked as follows: GII.1 > GII.6 > GII.4, with GII.4 being the most sensitive. Evaluation of temperature and matrix effects on HPP-mediated inactivation of HuNoV GII.4, GII.1, and GII.6 strains showed that HuNoV was more easily inactivated at lower temperatures and at a neutral pH. In addition, phosphate-buffered saline (PBS) and minimal essential medium (MEM) can provide protective effects against HuNoV inactivation compared to H2O. Collectively, this study demonstrated that (i) different HuNoV strains within GII exhibited different sensitivities to high pressure, and (ii) HPP is capable of inactivating HuNoV GII strains by optimizing pressure parameters. IMPORTANCE Human norovirus (HuNoV) is a leading cause of foodborne disease worldwide. Noroviruses are highly diverse, both antigenically and genetically. Genogroup II (GII) contains the majority of HuNoVs, with GII genotype 4 (GII.4) being the most prevalent

  14. Variable High-Pressure-Processing Sensitivities for Genogroup II Human Noroviruses.

    PubMed

    Lou, Fangfei; DiCaprio, Erin; Li, Xinhui; Dai, Xianjun; Ma, Yuanmei; Hughes, John; Chen, Haiqiang; Kingsley, David H; Li, Jianrong

    2016-10-01

    Human norovirus (HuNoV) is a leading cause of foodborne diseases worldwide. High-pressure processing (HPP) is one of the most promising nonthermal technologies for the decontamination of viral pathogens in foods. However, the survival of HuNoVs after HPP is poorly understood because these viruses cannot be propagated in vitro In this study, we estimated the survival of different HuNoV strains within genogroup II (GII) after HPP treatment using viral receptor-binding ability as an indicator. Four HuNoV strains (one GII genotype 1 [GII.1] strain, two GII.4 strains, and one GII.6 strain) were treated at high pressures ranging from 200 to 600 MPa. After treatment, the intact viral particles were captured by porcine gastric mucin-conjugated magnetic beads (PGM-MBs) that contained histo-blood group antigens, the functional receptors for HuNoVs. The genomic RNA copies of the captured HuNoVs were quantified by real-time reverse transcriptase PCR (RT-PCR). Two GII.4 HuNoVs had similar sensitivities to HPP. The resistance of HuNoV strains against HPP ranked as follows: GII.1 > GII.6 > GII.4, with GII.4 being the most sensitive. Evaluation of temperature and matrix effects on HPP-mediated inactivation of HuNoV GII.4, GII.1, and GII.6 strains showed that HuNoV was more easily inactivated at lower temperatures and at a neutral pH. In addition, phosphate-buffered saline (PBS) and minimal essential medium (MEM) can provide protective effects against HuNoV inactivation compared to H2O. Collectively, this study demonstrated that (i) different HuNoV strains within GII exhibited different sensitivities to high pressure, and (ii) HPP is capable of inactivating HuNoV GII strains by optimizing pressure parameters. Human norovirus (HuNoV) is a leading cause of foodborne disease worldwide. Noroviruses are highly diverse, both antigenically and genetically. Genogroup II (GII) contains the majority of HuNoVs, with GII genotype 4 (GII.4) being the most prevalent. Recently, GII.1 and GII.6

  15. Antiviral Effects of Lactococcus lactis on Feline Calicivirus, A Human Norovirus Surrogate.

    PubMed

    Aboubakr, Hamada A; El-Banna, Amr A; Youssef, Mohammed M; Al-Sohaimy, Sobhy A A; Goyal, Sagar M

    2014-12-01

    Foodborne viruses, particularly human norovirus (NV) and hepatitis virus type A, are a cause of concern for public health making it necessary to explore novel and effective techniques for prevention of foodborne viral contamination, especially in minimally processed and ready-to-eat foods. This study aimed to determine the antiviral activity of a probiotic lactic acid bacterium (LAB) against feline calicivirus (FCV), a surrogate of human NV. Bacterial growth medium filtrate (BGMF) of Lactococcus lactis subsp. lactis LM0230 and its bacterial cell suspension (BCS) were evaluated separately for their antiviral activity against FCV grown in Crandell-Reese feline kidney (CRFK) cells. No significant antiviral effect was seen when CRFK cells were pre-treated with either BGMF (raw or pH 7-adjusted BGMF) or BCS. However, pre-treatment of FCV with BGMF and BCS resulted in a reduction in virus titers of 1.3 log10 tissue culture infectious dose (TCID)50 and 1.8 log10 TCID50, respectively. The highest reductions in FCV infectivity were obtained when CRFK cells were co-treated with FCV and pH 7-adjusted BGMF or with FCV and BCS (7.5 log10 TCID50 and 6.0 log10 TCID50, respectively). These preliminary results are encouraging and indicate the need for continued studies on the role of probiotics and LAB on inactivation of viruses in various types of foods.

  16. Norovirus Mechanisms of Immune Antagonism

    PubMed Central

    Roth, Alexa N.; Karst, Stephanie M.

    2015-01-01

    Noroviruses are a leading cause of gastroenteritis outbreaks globally. Several lines of evidence indicate that noroviruses can antagonize or evade host immune responses, including the absence of long-lasting immunity elicited during a primary norovirus exposure and the ability of noroviruses to establish prolonged infections that are associated with protracted viral shedding. Specific norovirus proteins possessing immune antagonist activity have been described in recent years although mechanistic insight in most cases is limited. In this review, we discuss these emerging strategies used by noroviruses to subvert the immune response, including the actions of two nonstructural proteins (p48 and p22) to impair cellular protein trafficking and secretory pathways; the ability of the VF1 protein to inhibit cytokine induction; and the ability of the minor structural protein VP2 to regulate antigen presentation. We also discuss the current state of the understanding of host and viral factors regulating the establishment of persistent norovirus infections along the gastrointestinal tract. A more detailed understanding of immune antagonism by pathogenic viruses will inform prevention and treatment of disease. PMID:26673810

  17. A comparison of the thermal inactivation kinetics of human norovirus surrogates and hepatitis A virus in buffered cell culture medium.

    PubMed

    Bozkurt, Hayriye; D'Souza, Doris H; Davidson, P Michael

    2014-09-01

    Human noroviruses and hepatitis A virus (HAV) are considered as epidemiologically significant causes of foodborne disease. Therefore, studies are needed to bridge existing data gaps and determine appropriate parameters for thermal inactivation of human noroviruses and HAV. The objectives of this research were to compare the thermal inactivation kinetics of human norovirus surrogates (murine norovirus (MNV-1), and feline calicivirus (FCV-F9)) and HAV in buffered medium (2-ml vials), compare first-order and Weibull models to describe the data, calculate Arrhenius activation energy for each model, and evaluate model efficiency using selected statistical criteria. The D-values calculated from the first-order model (50-72 °C) ranged from 0.21-19.75 min for FCV-F9, 0.25-36.28 min for MNV-1, and 0.88-56.22 min for HAV. Using the Weibull model, the tD = 1 (time to destroy 1 log) for FCV-F9, MNV-1 and HAV at the same temperatures ranged from 0.10-13.27, 0.09-26.78, and 1.03-39.91 min, respectively. The z-values for FCV-F9, MNV-1, and HAV were 9.66 °C, 9.16 °C, and 14.50 °C, respectively, using the Weibull model. For the first order model, z-values were 9.36 °C, 9.32 °C, and 12.49 °C for FCV-F9, MNV-1, and HAV, respectively. For the Weibull model, estimated activation energies for FCV-F9, MNV-1, and HAV were 225, 278, and 182 kJ/mol, respectively, while the calculated activation energies for the first order model were 195, 202, and 171 kJ/mol, respectively. Knowledge of the thermal inactivation kinetics of norovirus surrogates and HAV will allow the development of processes that produce safer food products and improve consumer safety.

  18. Survival and inactivation of human norovirus surrogates in blueberry juice by high-pressure homogenization.

    PubMed

    Horm, Katie Marie; Davidson, P Michael; Harte, Federico M; D'Souza, Doris Helen

    2012-11-01

    Human noroviruses (HNoV) have been implicated in gastrointestinal outbreaks associated with fresh produce, juices, and ready-to-eat foods. In order to determine the risk of HNoV transmission by contaminated blueberry juice, survival characteristics of cultivable HNoV surrogates (murine norovirus, MNV-1; feline calicivirus, FCV-F9; and bacteriophage MS2) in blueberry juice (pH = 2.77) after 0, 1, 2, 7, 14, and 21 days at refrigeration temperatures (4°C) were studied. High-pressure homogenization (HPH) was studied as a novel processing method for noroviral surrogate inactivation in blueberry juice. Blueberry juice or phosphate-buffered saline (PBS; pH 7.2 as control) was inoculated with each virus, stored over 21 days at 4°C or subjected to HPH, and plaque assayed. FCV-F9 (∼5 log(10) PFU/mL) was undetectable after 1 day in blueberry juice at 4°C. MNV-1 (∼4 log(10) PFU/ml) showed minimal reduction (1 log(10) PFU/mL) after 14 days, with greater reduction (1.95 log(10) PFU/mL; p < 0.05) after 21 days in blueberry juice at 4°C. Bacteriophage MS2 (∼6 log(10) PFU/mL) showed significant reduction (1.93 log(10) PFU/mL; p < 0.05) after 2 days and was undetectable after 7 days in blueberry juice at 4°C. FCV-F9 remained viable in PBS for up to 21 days (2.28 log(10) PFU/mL reduction), while MNV-1 and MS2 survived after 21 days (1.08 and 0.56 log(10) PFU/mL reduction, respectively). Intriguingly, FCV-F9 and bacteriophage MS2 showed reduction after minimal homogenization pressures in blueberry juice (pH = 2.77), possibly due to the combination of juice pH, juice components, and mechanical effects. MNV-1 in blueberry juice was only slightly reduced at 250 (0.33 log(10) PFU/mL) and 300 MPa (0.71 log(10) PFU/mL). Virus surrogate survival in blueberry juice at 4°C correlates well with the ease of HNoV transmission via juices. HPH for viral inactivation in juices is dependent on virus type, and higher homogenization pressures may be needed for MNV-1 inactivation.

  19. Tenacity of human norovirus and the surrogates feline calicivirus and murine norovirus during long-term storage on common nonporous food contact surfaces.

    PubMed

    Mormann, Sascha; Heißenberg, Cathrin; Pfannebecker, Jens; Becker, Barbara

    2015-01-01

    The transfer of human norovirus (hNV) to food via contaminated surfaces is highly probable during food production, processing, and preparation. In this study, the tenacity of hNV and its cultivable surrogates feline calicivirus (FCV) and murine norovirus (MNV) on two common nonporous surface materials at two storage temperatures was directly compared. Virus titer reduction on artificially inoculated stainless steel and plastic carriers was monitored for 70 days at room temperature and at 7°C. Viruses were recovered at various time points by elution. Genomes from intact capsids (hNV, FCV, and MNV) were quantified with real-time reverse transcription (RT) PCR, and infectivity (FCV and MNV) was assessed with plaque assay. RNase treatment before RNA extraction was used to eliminate exposed RNA and to assess capsid integrity. No significant differences in titer reduction were found between materials (stainless steel or plastic) with the plaque assay or the real-time quantitative RT-PCR. At room temperature, infectious FCV and MNV were detected for 7 days. Titers of intact hNV, FCV, and MNV capsids dropped gradually and were still detectable after 70 days with a loss of 3 to 4 log units. At 7°C, the viruses were considerably more stable than they were at room temperature. Although only MNV infectivity was unchanged after 70 days, the numbers of intact capsids (hNV, FCV, and MNV) were stable with less than a 1-log reduction. The results indicate that hNV persists on food contact surfaces and seems to remain infective for weeks. MNV appears to be more stable than FCV at 7°C, and thus is the most suitable surrogate for hNV under dry conditions. Although a perfect quantitative correlation between intact capsids and infective particles was not obtained, real-time quantitative RT-PCR provided qualitative data about hNV inactivation characteristics. The results of this comparative study might support future efforts in assessment of foodborne virus risk and food safety.

  20. Norovirus gastroenteritis.

    PubMed

    Goodgame, Richard

    2007-03-01

    Recent epidemiologic studies have shown that norovirus is one of the most frequent causes of acute nonbacterial gastroenteritis. Reverse-transcription polymerase chain reaction and nucleotide sequencing are the means by which the hundreds of norovirus strains have been identified, named, and classified into genogroups and genetic clusters. They are also the means by which a particular strain is traced from the source of an outbreak throughout its spread. These molecular techniques have been combined with classic epidemiology to investigate norovirus outbreaks in diverse settings, including hospitals, nursing homes, dining locations, schools, daycare centers, and vacation venues. Outbreaks are difficult to control because of the apparent ease of transmission through food, water, person-to-person contact, and environmental surfaces. Almost all patients with norovirus gastroenteritis recover completely, but hospital and nursing home outbreaks have been associated with morbidity and mortality. The diagnostic and management approach to an individual patient is to use clinical and epidemiologic findings to rule out "not norovirus." At the first sign that there is an outbreak, strict compliance with cleaning, disinfection, and work release guidelines is important to prevent further spread.

  1. Prevalence of human norovirus and Clostridium difficile coinfections in adult hospitalized patients

    PubMed Central

    Stokely, Janelle N; Niendorf, Sandra; Taube, Stefan; Hoehne, Marina; Young, Vincent B; Rogers, Mary AM; Wobus, Christiane E

    2016-01-01

    Objective Human norovirus (HuNoV) and Clostridium difficile are common causes of infectious gastroenteritis in adults in the US. However, limited information is available regarding HuNoV and C. difficile coinfections. Our study was designed to evaluate the prevalence of HuNoV and C. difficile coinfections among adult patients in a hospital setting and disease symptomatology. Study design and setting For a cross-sectional analysis, 384 fecal samples were tested for the presence of C. difficile toxins from patients (n=290), whom the provider suspected of C. difficile infections. Subsequent testing was then performed for HuNoV genogroups I and II. Multinomial logistic regression was performed to determine symptoms more frequently associated with coinfections. Results The final cohort consisted of the following outcome groups: C. difficile (n=196), C. difficile + HuNoV coinfection (n=40), HuNoV only (n=12), and neither (n=136). Coinfected patients were more likely to develop nausea, gas, and abdominal pain and were more likely to seek treatment in the winter season compared with individuals not infected or infected with either pathogen alone. Conclusion Our study revealed that patients with coinfection are more likely to experience certain gastrointestinal symptoms, in particular abdominal pain, suggesting an increased severity of disease symptomatology in coinfected patients. PMID:27418856

  2. Fate of Human Noroviruses in Shellfish and Water Impacted by Frequent Sewage Pollution Events.

    PubMed

    Campos, Carlos J A; Avant, Justin; Gustar, Nicole; Lowther, James; Powell, Andy; Stockley, Louise; Lees, David N

    2015-07-21

    Knowledge of the fate of human noroviruses (NoV) in the marine environment is key to better controlling shellfish-related NoV gastroenteritis. We quantified NoV and Escherichia coli in sewage from storm tank discharges and treated effluent processed by a UV-disinfection plant following activated sludge treatment and studied the fate of these microorganisms in an oyster harvesting area impacted by frequent stormwater discharges and infrequent freshwater discharges. Oyster monitoring sites were positioned at intervals downstream from the wastewater treatment works (WwTW) outfall impacting the harvesting area. The decay rates of NoV in oysters as a function of the distance from the outfall were less rapid than those for E. coli that had concentrations of NoV of the same order of magnitude and were over 7 km away from the outfall. Levels of E. coli in oysters from more tidally influenced areas of the estuary were higher around high water than around low water, whereas tidal flows had no influence on NoV contamination in the oysters. The study provides comparative data on the contamination profiles and loadings of NoV and E. coli in a commercial oyster fishery impacted by a WwTW.

  3. Presence of human noroviruses on bathroom surfaces: a review of the literature.

    PubMed

    Leone, Cortney M; Tang, Chaoyi; Sharp, Julia; Jiang, Xiuping; Fraser, Angela

    2016-08-01

    Enteric viruses are the most common cause of acute gastroenteritis worldwide with most cases of illness attributed to caliciviruses, such as human noroviruses (HuNoV). While environmental transmission of HuNoV is reported to be low, environmental surfaces could be a source of secondary transmission. As many vomiting/fecal episodes occur in bathrooms, bathroom surfaces could be an important vehicle for transmitting HuNoV. We systematically reviewed the literature to determine the presence of HuNoV on bathroom surfaces. Our review included 22 eligible studies conducted in commercial and institutional settings. Under outbreak conditions, 11 studies reported detection rates of 20-100 %. Six studies implicated bathroom surfaces as primary sources of HuNoV infection while three reported HuNoV present on bathroom surfaces but indicated different primary sources. Under non-outbreak conditions, five studies reported detection rates of 2-17 %. Factors associated with HuNoV presence in bathrooms included population density, setting type, employee numbers, food handler knowledge, awareness, and behaviours, and cleaning/disinfecting procedures. Our review suggests bathrooms could be vehicles that transmit HuNoV under both outbreak and non-outbreak conditions.

  4. Antiviral effects of persimmon extract on human norovirus and its surrogate, bacteriophage MS2.

    PubMed

    Kamimoto, Maki; Nakai, Yoshiaki; Tsuji, Toru; Shimamoto, Toshi; Shimamoto, Tadashi

    2014-05-01

    Human noroviruses (NoVs) are the leading cause of gastroenteritis and foodborne illnesses worldwide. In this study, we investigated the effects of persimmon extract (PE) on NoV GII.4 and bacteriophage MS2. We also examined the relationship between the tannin content of PE and its antiviral effects to identify the active ingredient in PE. Different persimmon tannin (PT) solutions were prepared by mixing PE with different concentrations of bovine serum albumin. The antiviral efficacy of these solutions against NoV was evaluated by quantifying the amount of residual noroviral genome using a quantitative reverse transcription PCR (qRT-PCR) assay. The antiviral efficacy of PE against MS2 was examined with an infectivity assay (plaque assay). Solutions containing ≥ 0.11 mg/mL PT reduced the noroviral genome by more than 70.0% and the infectivity of MS2 by more than 2.5 log PFU/mL. However, the effects of PT on both viruses decreased markedly at a concentration of 0.08 mg/mL and solutions containing negligible PT had no antiviral activity. These results suggest that the PT component of PE inactivates NoV and MS2. Our results indicate that PE is a nontoxic antiviral agent effective against enteric viruses. Persimmon extract showed antiviral effects against NoV and bacteriophage MS2. Persimmon extract is suitable for use as an antiviral agent. © 2014 Institute of Food Technologists®

  5. Human norovirus occurrence and diversity in the Llobregat river catchment, Spain.

    PubMed

    Pérez-Sautu, Unai; Sano, Daisuke; Guix, Susana; Kasimir, Georg; Pintó, Rosa M; Bosch, Albert

    2012-02-01

    Human noroviruses (NoV) were quantified and characterized in an 18 month survey conducted along the Llobregat river catchment in Spain. Sample types included freshwater, untreated and treated wastewater and drinking water. High NoV genome copy numbers were reported, reaching up to 10(6)  l(-1) and 10(9)  l(-1) in freshwater and raw sewage respectively. In both types of samples, GII NoV genome copies outnumbered those of GI, although without significance. All samples of semi-treated and treated drinking water were negative for NoV. A clear seasonality of NoV occurrence was observed both in river water and sewage samples, with significantly higher genome copy numbers in the cold than in the warm months period. Mean NoV log reduction rates after biological treatment of sewage were 2.2 and 3.1 for GI and GII respectively. A total of 77 NoV strains isolated in the Llobregat river catchment could be phylogenetically characterized, 44 belonging to GI and 33 to GII. The most prevalent genotype was GI.4, followed by GII.4 and GII.21. Several variants of the pandemic GII.4 strain were detected in the environment, corroborating their circulation among the population. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  6. Antiviral activity of Ecasol against feline calicivirus, a surrogate of human norovirus.

    PubMed

    Chander, Yogesh; Johnson, Thomas; Goyal, Sagar M; Russell, R J

    2012-12-01

    Human norovirus (NoV) is a major cause of acute gastroenteritis in closed settings such as hospitals, hotels and cruise ships. The virus survives on inanimate surfaces for extended periods of time, and environmental contamination has been implicated in its transmission. The disinfection of contaminated areas is important in controlling the spread of NoV infections. Neutral solutions of electrochemically activated (ECA)-anolyte have been shown to be powerful disinfectants against a broad range of bacterial pathogens. The active chemical ingredient is hypochlorous acid (HOCl), which is registered as an approved food contact surface sanitizer in the United States by the Environmental Protection Agency, pursuant to 40 CFR 180.940. We evaluated the antiviral activity of Ecasol (an ECA-anolyte) against feline calicivirus (FCV), a surrogate of NoV. FCV dried on plastic surfaces was exposed to Ecasol for 1, 2, or 5min. After exposure to Ecasol, the virus titers were compared with untreated controls to determine the virus inactivation efficacy after different contact times. Ecasol was found to decrease the FCV titer by >5log(10) within 1min of contact, indicating its suitability for inactivation of NoV on surfaces. Copyright © 2012 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  7. Aerosolization of a Human Norovirus Surrogate, Bacteriophage MS2, during Simulated Vomiting

    PubMed Central

    Tung-Thompson, Grace; Libera, Dominic A.; Koch, Kenneth L.; de los Reyes, Francis L.; Jaykus, Lee-Ann

    2015-01-01

    Human noroviruses (NoV) are the leading cause of acute gastroenteritis worldwide. Epidemiological studies of outbreaks have suggested that vomiting facilitates transmission of human NoV, but there have been no laboratory-based studies characterizing the degree of NoV release during a vomiting event. The purpose of this work was to demonstrate that virus aerosolization occurs in a simulated vomiting event, and to estimate the amount of virus that is released in those aerosols. A simulated vomiting device was constructed at one-quarter scale of the human body following similitude principles. Simulated vomitus matrices at low (6.24 mPa*s) and high (177.5 mPa*s) viscosities were inoculated with low (108 PFU/mL) and high (1010 PFU/mL) concentrations of bacteriophage MS2 and placed in the artificial “stomach” of the device, which was then subjected to scaled physiologically relevant pressures associated with vomiting. Bio aerosols were captured using an SKC Biosampler. In low viscosity artificial vomitus, there were notable differences between recovered aerosolized MS2 as a function of pressure (i.e., greater aerosolization with increased pressure), although this was not always statistically significant. This relationship disappeared when using high viscosity simulated vomitus. The amount of MS2 aerosolized as a percent of total virus “vomited” ranged from 7.2 x 10-5 to 2.67 x 10-2 (which corresponded to a range of 36 to 13,350 PFU total). To our knowledge, this is the first study to document and measure aerosolization of a NoV surrogate in a similitude-based physical model. This has implications for better understanding the transmission dynamics of human NoV and for risk modeling purposes, both of which can help in designing effective infection control measures. PMID:26287612

  8. Aerosolization of a Human Norovirus Surrogate, Bacteriophage MS2, during Simulated Vomiting.

    PubMed

    Tung-Thompson, Grace; Libera, Dominic A; Koch, Kenneth L; de Los Reyes, Francis L; Jaykus, Lee-Ann

    2015-01-01

    Human noroviruses (NoV) are the leading cause of acute gastroenteritis worldwide. Epidemiological studies of outbreaks have suggested that vomiting facilitates transmission of human NoV, but there have been no laboratory-based studies characterizing the degree of NoV release during a vomiting event. The purpose of this work was to demonstrate that virus aerosolization occurs in a simulated vomiting event, and to estimate the amount of virus that is released in those aerosols. A simulated vomiting device was constructed at one-quarter scale of the human body following similitude principles. Simulated vomitus matrices at low (6.24 mPa*s) and high (177.5 mPa*s) viscosities were inoculated with low (108 PFU/mL) and high (1010 PFU/mL) concentrations of bacteriophage MS2 and placed in the artificial "stomach" of the device, which was then subjected to scaled physiologically relevant pressures associated with vomiting. Bio aerosols were captured using an SKC Biosampler. In low viscosity artificial vomitus, there were notable differences between recovered aerosolized MS2 as a function of pressure (i.e., greater aerosolization with increased pressure), although this was not always statistically significant. This relationship disappeared when using high viscosity simulated vomitus. The amount of MS2 aerosolized as a percent of total virus "vomited" ranged from 7.2 x 10-5 to 2.67 x 10-2 (which corresponded to a range of 36 to 13,350 PFU total). To our knowledge, this is the first study to document and measure aerosolization of a NoV surrogate in a similitude-based physical model. This has implications for better understanding the transmission dynamics of human NoV and for risk modeling purposes, both of which can help in designing effective infection control measures.

  9. Histo-blood group antigen-like substances of human enteric bacteria as specific adsorbents for human noroviruses.

    PubMed

    Miura, Takayuki; Sano, Daisuke; Suenaga, Atsushi; Yoshimura, Takeshi; Fuzawa, Miyu; Nakagomi, Toyoko; Nakagomi, Osamu; Okabe, Satoshi

    2013-09-01

    Histo-blood group antigens (HBGAs) have been suggested to be receptors or coreceptors for human noroviruses (HuNoVs) expressed on the intestinal epithelium. We isolated an enteric bacterium strain (SENG-6), closely related to Enterobacter cloacae, bearing HBGA-like substances from a fecal sample of a healthy individual by using a biopanning technique with anti-HBGA antibodies. The binding capacities of four genotypes of norovirus-like particles (NoVLPs) to Enterobacter sp. SENG-6 cells were confirmed by enzyme-linked immunosorbent assay (ELISA). Transmission electron microscopy demonstrated that NoVLPs bound mainly to extracellular polymeric substances (EPS) of Enterobacter sp. SENG-6, where the HBGA-like substances were localized. EPS that contained HBGA-like substances extracted from Enterobacter sp. SENG-6 was shown by enzyme-linked immunosorbent assay (ELISA) to be capable of binding to NoVLPs of a GI.1 wild-type strain (8fIIa) and a GII.6 strain that can recognize A antigen but not to an NoVLP GI.1 mutant strain (W375A) that loses the ability to bind to A antigen. Enzymatic cleavage of terminal N-acetyl-galactosamine residues in the bacterial EPS weakened bacterial EPS binding to the GI.1 wild-type strain (8fIIa). These results indicate that A-like substances in the bacterial EPS play a key role in binding to NoVLPs. Since the specific binding of HuNoVs to HBGA-positive enteric bacteria is likely to affect the transmission and infection processes of HuNoVs in their hosts and in the environment, further studies of human enteric bacteria and their binding capacity to HuNoVs will provide a new scientific platform for understanding interactions between two types of microbes that were previously regarded as biologically unrelated.

  10. Histo-Blood Group Antigen-Like Substances of Human Enteric Bacteria as Specific Adsorbents for Human Noroviruses

    PubMed Central

    Miura, Takayuki; Suenaga, Atsushi; Yoshimura, Takeshi; Fuzawa, Miyu; Nakagomi, Toyoko; Nakagomi, Osamu; Okabe, Satoshi

    2013-01-01

    Histo-blood group antigens (HBGAs) have been suggested to be receptors or coreceptors for human noroviruses (HuNoVs) expressed on the intestinal epithelium. We isolated an enteric bacterium strain (SENG-6), closely related to Enterobacter cloacae, bearing HBGA-like substances from a fecal sample of a healthy individual by using a biopanning technique with anti-HBGA antibodies. The binding capacities of four genotypes of norovirus-like particles (NoVLPs) to Enterobacter sp. SENG-6 cells were confirmed by enzyme-linked immunosorbent assay (ELISA). Transmission electron microscopy demonstrated that NoVLPs bound mainly to extracellular polymeric substances (EPS) of Enterobacter sp. SENG-6, where the HBGA-like substances were localized. EPS that contained HBGA-like substances extracted from Enterobacter sp. SENG-6 was shown by enzyme-linked immunosorbent assay (ELISA) to be capable of binding to NoVLPs of a GI.1 wild-type strain (8fIIa) and a GII.6 strain that can recognize A antigen but not to an NoVLP GI.1 mutant strain (W375A) that loses the ability to bind to A antigen. Enzymatic cleavage of terminal N-acetyl-galactosamine residues in the bacterial EPS weakened bacterial EPS binding to the GI.1 wild-type strain (8fIIa). These results indicate that A-like substances in the bacterial EPS play a key role in binding to NoVLPs. Since the specific binding of HuNoVs to HBGA-positive enteric bacteria is likely to affect the transmission and infection processes of HuNoVs in their hosts and in the environment, further studies of human enteric bacteria and their binding capacity to HuNoVs will provide a new scientific platform for understanding interactions between two types of microbes that were previously regarded as biologically unrelated. PMID:23804639

  11. High Protective Efficacy of Probiotics and Rice Bran against Human Norovirus Infection and Diarrhea in Gnotobiotic Pigs

    PubMed Central

    Lei, Shaohua; Ramesh, Ashwin; Twitchell, Erica; Wen, Ke; Bui, Tammy; Weiss, Mariah; Yang, Xingdong; Kocher, Jacob; Li, Guohua; Giri-Rachman, Ernawati; Trang, Nguyen Van; Jiang, Xi; Ryan, Elizabeth P.; Yuan, Lijuan

    2016-01-01

    Probiotics have been recognized as vaccine adjuvants and therapeutic agents to treat acute gastroenteritis in children. We previously showed that rice bran (RB) reduced human rotavirus diarrhea in gnotobiotic pigs. Human noroviruses (HuNoVs) are the major pathogens causing non-bacterial acute gastroenteritis worldwide. In this study, Lactobacillus rhamnosus GG (LGG) and Escherichia coli Nissle 1917 (EcN) were first screened for their ability to bind HuNoV P particles and virions derived from clinical samples containing HuNoV genotype GII.3 and GII.4, then the effects of LGG+EcN and RB on HuNoV infection and diarrhea were investigated using the gnotobiotic pig model. While LGG+EcN colonization inhibited HuNoV shedding, probiotic cocktail regimens in which RB feeding started 7 days prior to or 1 day after viral inoculation in the LGG+EcN colonized gnotobiotic pigs exhibited high protection against HuNoV diarrhea and shedding, characterized by significantly reduced incidence (89 versus 20%) and shorter mean duration of diarrhea (2.2 versus 0.2 days), as well as shorter mean duration of virus shedding (3.2 versus 1.0 days). In both probiotic cocktail groups, the diarrhea reduction rates were 78% compared with the control group, and diarrhea severity was reduced as demonstrated by the significantly lower cumulative fecal scores. The high protective efficacy of the probiotic cocktail regimens was attributed to stimulation of IFN-γ+ T cell responses, increased production of intestinal IgA and IgG, and maintenance of healthy intestinal morphology (manifested as longer villi compared with the control group). Therefore, probiotic cocktail regimens containing LGG+EcN and RB may represent highly efficacious strategies to prevent and treat HuNoV gastroenteritis, and potentially other human enteric pathogens. PMID:27853451

  12. High Protective Efficacy of Probiotics and Rice Bran against Human Norovirus Infection and Diarrhea in Gnotobiotic Pigs.

    PubMed

    Lei, Shaohua; Ramesh, Ashwin; Twitchell, Erica; Wen, Ke; Bui, Tammy; Weiss, Mariah; Yang, Xingdong; Kocher, Jacob; Li, Guohua; Giri-Rachman, Ernawati; Trang, Nguyen Van; Jiang, Xi; Ryan, Elizabeth P; Yuan, Lijuan

    2016-01-01

    Probiotics have been recognized as vaccine adjuvants and therapeutic agents to treat acute gastroenteritis in children. We previously showed that rice bran (RB) reduced human rotavirus diarrhea in gnotobiotic pigs. Human noroviruses (HuNoVs) are the major pathogens causing non-bacterial acute gastroenteritis worldwide. In this study, Lactobacillus rhamnosus GG (LGG) and Escherichia coli Nissle 1917 (EcN) were first screened for their ability to bind HuNoV P particles and virions derived from clinical samples containing HuNoV genotype GII.3 and GII.4, then the effects of LGG+EcN and RB on HuNoV infection and diarrhea were investigated using the gnotobiotic pig model. While LGG+EcN colonization inhibited HuNoV shedding, probiotic cocktail regimens in which RB feeding started 7 days prior to or 1 day after viral inoculation in the LGG+EcN colonized gnotobiotic pigs exhibited high protection against HuNoV diarrhea and shedding, characterized by significantly reduced incidence (89 versus 20%) and shorter mean duration of diarrhea (2.2 versus 0.2 days), as well as shorter mean duration of virus shedding (3.2 versus 1.0 days). In both probiotic cocktail groups, the diarrhea reduction rates were 78% compared with the control group, and diarrhea severity was reduced as demonstrated by the significantly lower cumulative fecal scores. The high protective efficacy of the probiotic cocktail regimens was attributed to stimulation of IFN-γ(+) T cell responses, increased production of intestinal IgA and IgG, and maintenance of healthy intestinal morphology (manifested as longer villi compared with the control group). Therefore, probiotic cocktail regimens containing LGG+EcN and RB may represent highly efficacious strategies to prevent and treat HuNoV gastroenteritis, and potentially other human enteric pathogens.

  13. Vitamin A Modifies the Intestinal Chemokine and Cytokine Responses to Norovirus Infection in Mexican Children12

    PubMed Central

    Long, Kurt Z.; Garcıa, Coralith; Ko, GwangPyo; Santos, Jose I.; Al Mamun, Abdullah; Rosado, Jorge L.; DuPont, Herbert L.; Nathakumar, Nanda

    2011-01-01

    Vitamin A supplementation is associated with divergent clinical norovirus (NoV) outcomes in Mexican children. Fecal cytokine concentrations following NoV genogroup infections among 127 Mexican children 5–15 mo old enrolled in a randomized, double-blind, placebo-controlled, vitamin A supplementation trial were determined to clarify the role the gut immune response plays in these associations. Stools collected from supplemented children [20,000 IU retinol (3.3 IU = 1 μg retinol) for children < 12 mo of age; 45,000 iu for children ≥ 12 mo] or children in the placebo group were screened for NoV genogroups I (GI) and II (GII). Monocyte chemoattractant protein-1 (MCP-1), TNFα, IL-5, IL-6, IL-8, IL-4, IFNγ, and IL-10 fecal concentrations were also determined. Differences in cytokine levels between the 2 groups following GI and GII infections were determined using ordered logistic regression models. MCP-1 and IL-8 levels were greater among GI- and GII-infected children, respectively, compared with uninfected children, whereas IL-5 levels were greater following both genogroup infections. MCP-1, IL-8, and IL-6 fecal levels were reduced among supplemented children with GII-associated diarrhea compared with the placebo group. Vitamin A–supplemented, GII-infected children had reduced MCP-1 and TNFα levels compared with GII-infected children in the placebo group (P-interaction = 0.02 and 0.03, respectively). Supplemented children with GI-associated diarrhea had higher TNFα and IL-4 levels compared with children in the placebo group with diarrhea (P-interaction = 0.02 and 0.02, respectively). The divergent effects of supplementation on NoV outcomes may result from the different effects vitamin A has on the genogroup-specific immune responses. PMID:21411606

  14. Vitamin A modifies the intestinal chemokine and cytokine responses to norovirus infection in Mexican children.

    PubMed

    Long, Kurt Z; Garcia, Coralith; Ko, GwangPyo; Santos, Jose I; Al Mamun, Abdullah; Rosado, Jorge L; DuPont, Herbert L; Nathakumar, Nanda

    2011-05-01

    Vitamin A supplementation is associated with divergent clinical norovirus (NoV) outcomes in Mexican children. Fecal cytokine concentrations following NoV genogroup infections among 127 Mexican children 5-15 mo old enrolled in a randomized, double-blind, placebo-controlled, vitamin A supplementation trial were determined to clarify the role the gut immune response plays in these associations. Stools collected from supplemented children [20,000 IU retinol (3.3 IU = 1 μg retinol) for children < 12 mo of age; 45,000 iu for children ≥ 12 mo] or children in the placebo group were screened for NoV genogroups I (GI) and II (GII). Monocyte chemoattractant protein-1 (MCP-1), TNFα, IL-5, IL-6, IL-8, IL-4, IFNγ, and IL-10 fecal concentrations were also determined. Differences in cytokine levels between the 2 groups following GI and GII infections were determined using ordered logistic regression models. MCP-1 and IL-8 levels were greater among GI- and GII-infected children, respectively, compared with uninfected children, whereas IL-5 levels were greater following both genogroup infections. MCP-1, IL-8, and IL-6 fecal levels were reduced among supplemented children with GII-associated diarrhea compared with the placebo group. Vitamin A-supplemented, GII-infected children had reduced MCP-1 and TNFα levels compared with GII-infected children in the placebo group (P-interaction = 0.02 and 0.03, respectively). Supplemented children with GI-associated diarrhea had higher TNFα and IL-4 levels compared with children in the placebo group with diarrhea (P-interaction = 0.02 and 0.02, respectively). The divergent effects of supplementation on NoV outcomes may result from the different effects vitamin A has on the genogroup-specific immune responses.

  15. Crystallography of a Lewis-Binding Norovirus, Elucidation of Strain-Specificity to the Polymorphic Human Histo-Blood Group Antigens

    PubMed Central

    Xia, Ming; Hao, Ning; Zhang, Xuejun C.; Huang, Pengwei; Jiang, Xi; Li, Xuemei; Rao, Zihe

    2011-01-01

    Noroviruses, an important cause of acute gastroenteritis in humans, recognize the histo-blood group antigens (HBGAs) as host susceptible factors in a strain-specific manner. The crystal structures of the HBGA-binding interfaces of two A/B/H-binding noroviruses, the prototype Norwalk virus (GI.1) and a predominant GII.4 strain (VA387), have been elucidated. In this study we determined the crystal structures of the P domain protein of the first Lewis-binding norovirus (VA207, GII.9) that has a distinct binding property from those of Norwalk virus and VA387. Co-crystallization of the VA207 P dimer with Ley or sialyl Lex tetrasaccharides showed that VA207 interacts with these antigens through a common site found on the VA387 P protein which is highly conserved among most GII noroviruses. However, the HBGA-binding site of VA207 targeted at the Lewis antigens through the α-1, 3 fucose (the Lewis epitope) as major and the β-N-acetyl glucosamine of the precursor as minor interacting sites. This completely differs from the binding mode of VA387 and Norwalk virus that target at the secretor epitopes. Binding pocket of VA207 is formed by seven amino acids, of which five residues build up the core structure that is essential for the basic binding function, while the other two are involved in strain-specificity. Our results elucidate for the first time the genetic and structural basis of strain-specificity by a direct comparison of two genetically related noroviruses in their interaction with different HBGAs. The results provide insight into the complex interaction between the diverse noroviruses and the polymorphic HBGAs and highlight the role of human HBGA as a critical factor in norovirus evolution. PMID:21811409

  16. Norovirus: Food Handlers

    MedlinePlus

    ... Health, NEHA, Water Quality & Health Council, and American Chemistry Council Clean-up and Disinfection for Norovirus (“ ... Health, NEHA, Water Quality & Health Council, and American Chemistry Council Norovirus Illness: Key Facts [2 pages] Norovirus: ...

  17. Norovirus Illness: Key Facts

    MedlinePlus

    ... for days or weeks. • Norovirus can survive some disinfectants, making it hard to get rid of. Norovirus ... 5.25%] per gallon of water) or other disinfectant registered as effective against norovirus by the Environmental ...

  18. Structural basis for norovirus neutralization by an HBGA blocking human IgA antibody.

    PubMed

    Shanker, Sreejesh; Czakó, Rita; Sapparapu, Gopal; Alvarado, Gabriela; Viskovska, Maria; Sankaran, Banumathi; Atmar, Robert L; Crowe, James E; Estes, Mary K; Prasad, B V Venkataram

    2016-10-04

    Human noroviruses (HuNoVs) cause sporadic and epidemic gastroenteritis worldwide. They are classified into two major genogroups (GI and GII), with each genogroup further divided into multiple genotypes. Susceptibility to these viruses is influenced by genetically determined histo-blood group antigen (HBGA) expression. HBGAs function as cell attachment factors by binding to a surface-exposed region in the protruding (P) domain of the capsid protein. Sequence variations in this region that result in differential HBGA binding patterns and antigenicity are suggested to form a basis for strain diversification. Recent studies show that serum antibodies that block HBGA binding correlate with protection against illness. Although genogroup-dependent variation in HBGA binding specificity is structurally well characterized, an understanding of how antibodies block HBGA binding and how genotypic variations affect such blockade is lacking. Our crystallographic studies of the GI.1 P domain in complex with the Fab fragment of a human IgA monoclonal antibody (IgA 5I2) with HBGA blocking activity show that the antibody recognizes a conformational epitope formed by two surface-exposed loop clusters in the P domain. The antibody engulfs the HBGA binding site but does not affect its structural integrity. An unusual feature of the antigen recognition by IgA 5I2 is the predominant involvement of the CDR light chain 1 in contrast to the commonly observed CDR heavy chain 3, providing a unique perspective into antibody diversity in antigen recognition. Identification of the antigenic site in the P domain shows how genotypic variations might allow escape from antibody neutralization and exemplifies the interplay between antigenicity and HBGA specificity in HuNoV evolution.

  19. Human norovirus in untreated sewage and effluents from primary, secondary and tertiary treatment processes.

    PubMed

    Campos, Carlos J A; Avant, Justin; Lowther, James; Till, Dale; Lees, David N

    2016-10-15

    Wastewater treatments are considered important means to control the environmental transmission of human norovirus (NoV). Information about NoV concentrations in untreated and treated effluents, their seasonality and typical removal rates achieved by different treatment processes is required to assess the effectiveness of sewage treatment processes in reducing human exposure to NoV. This paper reports on a characterisation of concentrations of NoV (genogroups I and II) in untreated sewage (screened influent) and treated effluents from five full scale wastewater treatment works (WwTW) in England. Results are shown for effluent samples characteristic of primary- (primary settlement, storm tank overflows), secondary- (activated sludge, trickling filters, humus tanks) and tertiary (UV disinfection) treatments. NoV occurrence in untreated sewage varied between years. This variation was consistent with the annual variation of the virus in the community as indicated by outbreak laboratory reports. Significant differences were found between mean NoV concentrations in effluents subject to different levels of treatment. Primary settlement achieved approximately 1 log10 removal for both genogroups. Concentrations of NoV and Escherichia coli in untreated sewage were of the same order of magnitude of those in storm tank overflows. Of the secondary treatments studied, activated sludge was the most effective in removing NoV with mean log10 removals of 3.11 and 2.34 for GI and GII, respectively. The results of this study provide evidence that monitoring of NoV in raw sewage or treated effluents could provide early warning of an elevated risk for NoV and potentially help prevent outbreaks through environmental exposure. They also provide evidence that elimination of stormwater discharges and improvement of the efficiency of activated sludge for NoV removal would be effective for reducing the risk of environmental transmission. Crown Copyright © 2016. Published by Elsevier Ltd. All

  20. Regulation of Norovirus Virulence by the VP1 Protruding Domain Correlates with B Cell Infection Efficiency

    PubMed Central

    Zhu, Shu; Watanabe, Makiko; Kirkpatrick, Ericka; Murray, Akilah B.; Sok, Ryneth

    2015-01-01

    ABSTRACT Human noroviruses are a leading cause of gastroenteritis across the globe, but the pathogenic mechanisms responsible for disease are not well established. The availability of a murine norovirus model system provides the opportunity to elucidate viral and host determinants of virulence in a natural host. For example, previous studies have revealed that the protruding domain of the murine norovirus capsid protein VP1, specifically residue 296 of VP1, regulates virulent infection. We identified a panel of nonsynonymous mutations in the open reading frame 2 (ORF2) gene encoding VP1 that arose in persistently infected mice and tested whether these mutations conferred phenotypic changes to viral replication and virulence. Consistent with previous studies, we demonstrate that a glutamic acid at position 296 results in attenuation. For the first time, we also demonstrate that a lysine at this position is sufficient to confer virulence on an otherwise attenuated murine norovirus strain. Moreover, our studies reveal a direct correlation between the efficiency of viral replication in B cells and virulence. These data are especially striking because mutations causing reduced B cell replication and attenuation had minimal effects on the ability of the virus to replicate in macrophages. Thus, norovirus infection of B cells may directly contribute to disease outcome. IMPORTANCE Human noroviruses are a major global cause of disease, yet we know very little about their pathogenic mechanisms. The availability of a murine norovirus model system facilitates investigation of noroviruses in a natural host organism and the identification of viral and host determinants of pathogenesis. We have identified a panel of mutations arising in the viral capsid protein VP1 during persistent infection of mice. Our data reveal that the protruding domain of VP1 regulates the ability of the virus to replicate in B cells, and this directly correlates with virulence. Importantly, mutations

  1. Wipes Coated with a Singlet-Oxygen-Producing Photosensitizer Are Effective against Human Influenza Virus but Not against Norovirus

    PubMed Central

    Bouwknegt, Martijn; Rutjes, Saskia; de Roda Husman, Ana Maria

    2014-01-01

    Transmission of enteric and respiratory viruses, including human norovirus (hNoV) and human influenza virus, may involve surfaces. In food preparation and health care settings, surfaces are cleaned with wipes; however, wiping may not efficiently reduce contamination or may even spread viruses, increasing a potential public health risk. The virucidal properties of wipes with a singlet-oxygen-generating immobilized photosensitizer (IPS) coating were compared to those of similar but uncoated wipes (non-IPS) and of commonly used viscose wipes. Wipes were spiked with hNoV GI.4 and GII.4, murine norovirus 1 (MNV-1), human adenovirus type 5 (hAdV-5), and influenza virus H1N1 to study viral persistence. We also determined residual and transferred virus proportions on steel carriers after successively wiping a contaminated and an uncontaminated steel carrier. On IPS wipes only, influenza viruses were promptly inactivated with a 5-log10 reduction. D values of infectious MNV-1 and hAdV-5 were 8.7 and 7.0 h on IPS wipes, 11.6 and 9.3 h on non-IPS wipes, and 10.2 and 8.2 h on viscose wipes, respectively. Independently of the type of wipe, dry cleaning removed, or drastically reduced, initial spot contamination of hNoV on surfaces. All wipes transferred hNoV to an uncontaminated carrier; however, the risk of continued transmission by reuse of wipes after 6 and 24 h was limited for all viruses. We conclude that cleaning wet spots with dry wipes efficiently reduced spot contamination on surfaces but that cross-contamination with noroviruses by wiping may result in an increased public health risk at high initial virus loads. For influenza virus, IPS wipes present an efficient one-step procedure for cleaning and disinfecting contaminated surfaces. PMID:24814795

  2. Genome Sequence of Enterobacter cloacae Strain SENG-6, a Bacterium Producing Histo-Blood Group Antigen-Like Substances That Can Bind with Human Noroviruses

    PubMed Central

    Amarasiri, Mohan; Hashiba, Satoshi; Yang, Peiyi; Okabe, Satoshi

    2016-01-01

    Enterobacter sp. strain SENG-6, isolated from healthy human feces, produces histo-blood group antigen (HBGA)-like substances that can bind with human noroviruses. Based on the genome sequence analysis, strain SENG-6 belongs to the species Enterobacter cloacae. The genome sequence of this strain should help identify genes associated with the production of HBGA-like substances. PMID:27563051

  3. Genome Sequence of Enterobacter cloacae Strain SENG-6, a Bacterium Producing Histo-Blood Group Antigen-Like Substances That Can Bind with Human Noroviruses.

    PubMed

    Ishii, Satoshi; Amarasiri, Mohan; Hashiba, Satoshi; Yang, Peiyi; Okabe, Satoshi; Sano, Daisuke

    2016-08-25

    Enterobacter sp. strain SENG-6, isolated from healthy human feces, produces histo-blood group antigen (HBGA)-like substances that can bind with human noroviruses. Based on the genome sequence analysis, strain SENG-6 belongs to the species Enterobacter cloacae The genome sequence of this strain should help identify genes associated with the production of HBGA-like substances.

  4. Two Alternative Ways of Start Site Selection in Human Norovirus Reinitiation of Translation*

    PubMed Central

    Luttermann, Christine; Meyers, Gregor

    2014-01-01

    The calicivirus minor capsid protein VP2 is expressed via termination/reinitiation. This process depends on an upstream sequence element denoted termination upstream ribosomal binding site (TURBS). We have shown for feline calicivirus and rabbit hemorrhagic disease virus that the TURBS contains three sequence motifs essential for reinitiation. Motif 1 is conserved among caliciviruses and is complementary to a sequence in the 18 S rRNA leading to the model that hybridization between motif 1 and 18 S rRNA tethers the post-termination ribosome to the mRNA. Motif 2 and motif 2* are proposed to establish a secondary structure positioning the ribosome relative to the start site of the terminal ORF. Here, we analyzed human norovirus (huNV) sequences for the presence and importance of these motifs. The three motifs were identified by sequence analyses in the region upstream of the VP2 start site, and we showed that these motifs are essential for reinitiation of huNV VP2 translation. More detailed analyses revealed that the site of reinitiation is not fixed to a single codon and does not need to be an AUG, even though this codon is clearly preferred. Interestingly, we were able to show that reinitiation can occur at AUG codons downstream of the canonical start/stop site in huNV and feline calicivirus but not in rabbit hemorrhagic disease virus. Although reinitiation at the original start site is independent of the Kozak context, downstream initiation exhibits requirements for start site sequence context known for linear scanning. These analyses on start codon recognition give a more detailed insight into this fascinating mechanism of gene expression. PMID:24599949

  5. Two alternative ways of start site selection in human norovirus reinitiation of translation.

    PubMed

    Luttermann, Christine; Meyers, Gregor

    2014-04-25

    The calicivirus minor capsid protein VP2 is expressed via termination/reinitiation. This process depends on an upstream sequence element denoted termination upstream ribosomal binding site (TURBS). We have shown for feline calicivirus and rabbit hemorrhagic disease virus that the TURBS contains three sequence motifs essential for reinitiation. Motif 1 is conserved among caliciviruses and is complementary to a sequence in the 18 S rRNA leading to the model that hybridization between motif 1 and 18 S rRNA tethers the post-termination ribosome to the mRNA. Motif 2 and motif 2* are proposed to establish a secondary structure positioning the ribosome relative to the start site of the terminal ORF. Here, we analyzed human norovirus (huNV) sequences for the presence and importance of these motifs. The three motifs were identified by sequence analyses in the region upstream of the VP2 start site, and we showed that these motifs are essential for reinitiation of huNV VP2 translation. More detailed analyses revealed that the site of reinitiation is not fixed to a single codon and does not need to be an AUG, even though this codon is clearly preferred. Interestingly, we were able to show that reinitiation can occur at AUG codons downstream of the canonical start/stop site in huNV and feline calicivirus but not in rabbit hemorrhagic disease virus. Although reinitiation at the original start site is independent of the Kozak context, downstream initiation exhibits requirements for start site sequence context known for linear scanning. These analyses on start codon recognition give a more detailed insight into this fascinating mechanism of gene expression.

  6. Inactivation of human norovirus in contaminated oysters and clams by high hydrostatic pressure.

    PubMed

    Ye, Mu; Li, Xinhui; Kingsley, David H; Jiang, Xi; Chen, Haiqiang

    2014-04-01

    Human norovirus (NoV) is the most frequent causative agent of food-borne disease associated with shellfish consumption. In this study, the effect of high hydrostatic pressure (HHP) on inactivation of NoV was determined. Genogroup I.1 (GI.1) or genogroup II.4 (GII.4) NoV was inoculated into oyster homogenates and treated at 300 to 600 MPa at 25, 6, and 1°C for 5 min. After HHP, samples were treated with RNase and viral particles were extracted with porcine gastric mucin (PGM)-conjugated magnetic beads (PGM-MBs). Viral RNA was then quantified by real-time reverse transcription (RT)-PCR. Since PGM contains histo-blood group-like antigens, which can act as receptors for NoV, deficiency for binding to PGM is an indication of loss of infectivity of NoV. After binding to PGM-MBs, RT-PCR-detectable NoV RNA in oysters was reduced by 0.4 to >4 log10 by HHP at 300 to 600 MPa. The GI.1 NoV was more resistant to HHP than the GII.4 NoV (P < 0.05). HHP at lower temperatures significantly enhanced the inactivation of NoV in oysters (P < 0.05). Pressure treatment was also conducted for clam homogenates. Treatment at 450 MPa at 1°C achieved a >4 log10 reduction of GI.1 NoV in both oyster and clam homogenates. It is therefore concluded that HHP could be applied as a potential intervention for inactivating NoV in raw shellfish. The method of pretreatment of samples with RNase, extraction of viral particles using PGM-MB binding, and quantification of viral RNA using RT-PCR can be explored as a practical means of distinguishing between infectious and noninfectious NoV.

  7. Interaction of microorganisms within leafy green phyllospheres: Where do human noroviruses fit in?

    PubMed

    Deng, Wenjun; Gibson, Kristen E

    2017-10-03

    Human noroviruses (hNoV) are one of the major causes of foodborne disease outbreaks linked to leafy greens. However, the interactions-including attachment and persistence-of hNoV with leafy greens are not well characterized. In the present review, three mechanisms are hypothesized for the interaction of hNoV with leafy green phyllospheres: 1) specific binding to histo-blood group antigen (HBGA)-like carbohydrates exposed on leaf surfaces and present on bacterial microbiota; 2) non-specific binding through electrostatic forces; and 3) internalization of hNoV through contaminated water (e.g. hydroponic feed water). To add more complexity, there is a rich diversity of microbial communities (i.e., bacteria, fungi, protozoa) residing in leafy green phyllospheres, and the attachment and persistence of hNoV could be largely impacted by these microorganisms through direct and indirect interactions. For instance, enzymes produced by bacteria and fungi could potentially compromise the structure of HBGA-like carbohydrate binding sites on leaves, leading to a reduction in hNoV binding. On the other hand, some bacteria also possess HBGA-like binding sites on their cell surface, which may provide extra binding locations for hNoV. There are also numerous metabolic compounds that can be produced by leafy greens and its microbial inhabitants and be subsequently distributed within leafy green phyllospheres. These compounds could theoretically play roles in enhancement or reduction in the attachment of hNoV. Overall, increasing the understanding of the various types of hNoV attachment and interactions with leafy green phyllospheres will be crucial for elucidating hNoV transmission via leafy greens as well as for the development of effective control measures. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Postharvest Survival of Porcine Sapovirus, a Human Norovirus Surrogate, on Phytopathogen-Infected Leafy Greens.

    PubMed

    Esseili, Malak A; Chin, Ashlina; Saif, Linda; Miller, Sally A; Qu, Feng; Lewis Ivey, Melanie L; Wang, Qiuhong

    2015-08-01

    Leafy greens are increasingly being recognized as an important vehicle for human noroviruses (HuNoV), which cause recurring gastroenteritis outbreaks. Leafy greens often become infected by phytopathogens in the field, which may cause symptoms on the edible parts. Whether plant pathogen infections enhance the survival of HuNoV on leafy greens is unknown. Lettuce and spinach plants were infected with a bacterium, Xanthomonas campestris pv. vitians strain 701a, and with Cucumber mosaic virus strain Fny, respectively. The survival rate of porcine sapovirus (SaV), a HuNoV surrogate, on infected and noninfected postharvest leaves was then assessed. In addition, acibenzolar-S-methyl, a commercial chemical elicitor of plant systemic defense, was used to assess whether stimulating the plant host defense affects the postharvest survival of SaV. Leaves harvested from control and treated plants were inoculated with SaV and incubated for 7 days at 4°C. The infectivity (tissue culture infectious dose affecting 50% of the culture [TCID50]/ml) and RNA (genomic equivalent/ml) titers of SaV were assayed using immunohistochemistry staining and SaV-specific TaqMan real-time reverse transcription PCR. Our results showed that cucumber mosaic virus Fny induced mild, nonnecrotic symptoms on spinach leaves and had no effect on SaV survival. In contrast, X. campestris pv. vitians 701a induced small localized necrotic lesions and significantly enhanced SaV survival on lettuce leaves. Treatment with acibenzolar-S-methyl was effective in reducing X. campestris pv. vitians 701a-induced lesions on infected lettuce plants but had no direct effect on SaV survival when used on healthy lettuce plants. These findings indicate that phytopathogen-induced necrotic lesions may enhance the postharvest survival of HuNoV on lettuce leaves. Therefore, preventive measures aiming to maintain healthy plants and minimize preharvest biological damage are expected to improve the safety of leafy greens.

  9. Enhanced Removal of a Human Norovirus Surrogate from Fresh Vegetables and Fruits by a Combination of Surfactants and Sanitizers▿

    PubMed Central

    Predmore, Ashley; Li, Jianrong

    2011-01-01

    Fruits and vegetables are major vehicles for transmission of food-borne enteric viruses since they are easily contaminated at pre- and postharvest stages and they undergo little or no processing. However, commonly used sanitizers are relatively ineffective for removing human norovirus surrogates from fresh produce. In this study, we systematically evaluated the effectiveness of surfactants on removal of a human norovirus surrogate, murine norovirus 1 (MNV-1), from fresh produce. We showed that a panel of surfactants, including sodium dodecyl sulfate (SDS), Nonidet P-40 (NP-40), Triton X-100, and polysorbates, significantly enhanced the removal of viruses from fresh fruits and vegetables. While tap water alone and chlorine solution (200 ppm) gave only <1.2-log reductions in virus titer in all fresh produce, a solution containing 50 ppm of surfactant was able to achieve a 3-log reduction in virus titer in strawberries and an approximately 2-log reduction in virus titer in lettuce, cabbage, and raspberries. Moreover, a reduction of approximately 3 logs was observed in all the tested fresh produce after sanitization with a solution containing a combination of 50 ppm of each surfactant and 200 ppm of chlorine. Taken together, our results demonstrate that the combination of a surfactant with a commonly used sanitizer enhanced the efficiency in removing viruses from fresh produce by approximately 100 times. Since SDS is an FDA-approved food additive and polysorbates are recognized by the FDA as GRAS (generally recognized as safe) products, implementation of this novel sanitization strategy would be a feasible approach for efficient reduction of the virus load in fresh produce. PMID:21622782

  10. Zeta Potential and Aggregation of Virus-Like Particle of Human Norovirus and Feline Calicivirus Under Different Physicochemical Conditions.

    PubMed

    Samandoulgou, Idrissa; Fliss, Ismaïl; Jean, Julie

    2015-09-01

    Although the spread of human norovirus reportedly depends on its ability to bind to food materials, the mechanism of the phenomenon remains unknown. Since protein size and electrical charge are reportedly important parameters in their adsorption, the current work is focused on determining human noroviruses isoelectric point (IEP), electrical charge and aggregate size at different pH, ionic strength (IS), and temperature. Using the baculovirus expression vector system, we produced and purified virus-like particles (VLPs) of GI.1 and GII.4 noroviruses and feline calicivirus, determined their IEP, and examined their size and electrical charge using a Zetasizer Nano ZS apparatus. Shape and size were also visualized using transmission electron microscopy. IEPs were found close to pH 4. Net charge increased as the pH deviated from the IEP. VLPs were negatively charged at all IS tested and showed a gradual decrease in charge with increasing IS. At low temperature, VLPs were 20-45 nm in diameter at pH far from their IEP and under almost all IS conditions, while aggregates appeared at or near the IEP. At increased temperatures, aggregates appeared at or near the IEP and at high IS. Aggregation at the IEP was also confirmed by microscopy. This suggests that electrostatic interactions would be the predominant factor in VLPs adhesion at pH far from 4 and at low ionic strength. In contrast, non-electrostatic interactions would prevail at around pH 4 and would be reinforced by aggregates, since size generally favors multiple bonding with sorbents.

  11. Enhanced removal of a human norovirus surrogate from fresh vegetables and fruits by a combination of surfactants and sanitizers.

    PubMed

    Predmore, Ashley; Li, Jianrong

    2011-07-01

    Fruits and vegetables are major vehicles for transmission of food-borne enteric viruses since they are easily contaminated at pre- and postharvest stages and they undergo little or no processing. However, commonly used sanitizers are relatively ineffective for removing human norovirus surrogates from fresh produce. In this study, we systematically evaluated the effectiveness of surfactants on removal of a human norovirus surrogate, murine norovirus 1 (MNV-1), from fresh produce. We showed that a panel of surfactants, including sodium dodecyl sulfate (SDS), Nonidet P-40 (NP-40), Triton X-100, and polysorbates, significantly enhanced the removal of viruses from fresh fruits and vegetables. While tap water alone and chlorine solution (200 ppm) gave only <1.2-log reductions in virus titer in all fresh produce, a solution containing 50 ppm of surfactant was able to achieve a 3-log reduction in virus titer in strawberries and an approximately 2-log reduction in virus titer in lettuce, cabbage, and raspberries. Moreover, a reduction of approximately 3 logs was observed in all the tested fresh produce after sanitization with a solution containing a combination of 50 ppm of each surfactant and 200 ppm of chlorine. Taken together, our results demonstrate that the combination of a surfactant with a commonly used sanitizer enhanced the efficiency in removing viruses from fresh produce by approximately 100 times. Since SDS is an FDA-approved food additive and polysorbates are recognized by the FDA as GRAS (generally recognized as safe) products, implementation of this novel sanitization strategy would be a feasible approach for efficient reduction of the virus load in fresh produce.

  12. Thermal Inactivation Kinetics of Human Norovirus Surrogates and Hepatitis A Virus in Turkey Deli Meat.

    PubMed

    Bozkurt, Hayriye; D'Souza, Doris H; Davidson, P Michael

    2015-07-01

    Human noroviruses (HNoV) and hepatitis A virus (HAV) have been implicated in outbreaks linked to the consumption of presliced ready-to-eat deli meats. The objectives of this research were to determine the thermal inactivation kinetics of HNoV surrogates (murine norovirus 1 [MNV-1] and feline calicivirus strain F9 [FCV-F9]) and HAV in turkey deli meat, compare first-order and Weibull models to describe the data, and calculate Arrhenius activation energy values for each model. The D (decimal reduction time) values in the temperature range of 50 to 72°C calculated from the first-order model were 0.1 ± 0.0 to 9.9 ± 3.9 min for FCV-F9, 0.2 ± 0.0 to 21.0 ± 0.8 min for MNV-1, and 1.0 ± 0.1 to 42.0 ± 5.6 min for HAV. Using the Weibull model, the tD = 1 (time to destroy 1 log) values for FCV-F9, MNV-1, and HAV at the same temperatures ranged from 0.1 ± 0.0 to 11.9 ± 5.1 min, from 0.3 ± 0.1 to 17.8 ± 1.8 min, and from 0.6 ± 0.3 to 25.9 ± 3.7 min, respectively. The z (thermal resistance) values for FCV-F9, MNV-1, and HAV were 11.3 ± 2.1°C, 11.0 ± 1.6°C, and 13.4 ± 2.6°C, respectively, using the Weibull model. The z values using the first-order model were 11.9 ± 1.0°C, 10.9 ± 1.3°C, and 12.8 ± 1.7°C for FCV-F9, MNV-1, and HAV, respectively. For the Weibull model, estimated activation energies for FCV-F9, MNV-1, and HAV were 214 ± 28, 242 ± 36, and 154 ± 19 kJ/mole, respectively, while the calculated activation energies for the first-order model were 181 ± 16, 196 ± 5, and 167 ± 9 kJ/mole, respectively. Precise information on the thermal inactivation of HNoV surrogates and HAV in turkey deli meat was generated. This provided calculations of parameters for more-reliable thermal processes to inactivate viruses in contaminated presliced ready-to-eat deli meats and thus to reduce the risk of foodborne illness outbreaks.

  13. Thermal Inactivation Kinetics of Human Norovirus Surrogates and Hepatitis A Virus in Turkey Deli Meat

    PubMed Central

    Bozkurt, Hayriye; Davidson, P. Michael

    2015-01-01

    Human noroviruses (HNoV) and hepatitis A virus (HAV) have been implicated in outbreaks linked to the consumption of presliced ready-to-eat deli meats. The objectives of this research were to determine the thermal inactivation kinetics of HNoV surrogates (murine norovirus 1 [MNV-1] and feline calicivirus strain F9 [FCV-F9]) and HAV in turkey deli meat, compare first-order and Weibull models to describe the data, and calculate Arrhenius activation energy values for each model. The D (decimal reduction time) values in the temperature range of 50 to 72°C calculated from the first-order model were 0.1 ± 0.0 to 9.9 ± 3.9 min for FCV-F9, 0.2 ± 0.0 to 21.0 ± 0.8 min for MNV-1, and 1.0 ± 0.1 to 42.0 ± 5.6 min for HAV. Using the Weibull model, the tD = 1 (time to destroy 1 log) values for FCV-F9, MNV-1, and HAV at the same temperatures ranged from 0.1 ± 0.0 to 11.9 ± 5.1 min, from 0.3 ± 0.1 to 17.8 ± 1.8 min, and from 0.6 ± 0.3 to 25.9 ± 3.7 min, respectively. The z (thermal resistance) values for FCV-F9, MNV-1, and HAV were 11.3 ± 2.1°C, 11.0 ± 1.6°C, and 13.4 ± 2.6°C, respectively, using the Weibull model. The z values using the first-order model were 11.9 ± 1.0°C, 10.9 ± 1.3°C, and 12.8 ± 1.7°C for FCV-F9, MNV-1, and HAV, respectively. For the Weibull model, estimated activation energies for FCV-F9, MNV-1, and HAV were 214 ± 28, 242 ± 36, and 154 ± 19 kJ/mole, respectively, while the calculated activation energies for the first-order model were 181 ± 16, 196 ± 5, and 167 ± 9 kJ/mole, respectively. Precise information on the thermal inactivation of HNoV surrogates and HAV in turkey deli meat was generated. This provided calculations of parameters for more-reliable thermal processes to inactivate viruses in contaminated presliced ready-to-eat deli meats and thus to reduce the risk of foodborne illness outbreaks. PMID:25956775

  14. Inactivation of human norovirus surrogates by benzalkonium chloride, potassium peroxymonosulfate, tannic acid, and gallic acid.

    PubMed

    Su, Xiaowei; D'Souza, Doris H

    2012-09-01

    Novel methods to effectively disinfect contact surfaces and prevent human norovirus transmission are essential. The effect of benzalkonium chloride (BAC), potassium peroxymonosulfate (KPMS), tannic acid (TA), and gallic acid (GA) on enteric virus surrogates, murine norovirus (MNV-1), feline calicivirus (FCV-F9), and bacteriophage MS2 was studied. Viruses at high (∼7 log₁₀ PFU/mL) or low (∼5 log₁₀ PFU/mL) titers were mixed with equal volumes of BAC (0.2, 0.5, and 1 mg/mL), KPMS (5, 10, and 20 mg/mL), TA (0.02 and 0.2 mg/mL), GA (0.2, 0.4, and 0.8 mg/mL), or water and incubated for 2 h at room temperature. Viral infectivity after triplicate treatments was evaluated using plaque assays in duplicate. Low titers of FCV-F9 and MNV-1 were completely reduced, while low-titer MS2 was reduced by 1.7-1.8 log₁₀ PFU/mL with BAC at all three concentrations. High-titer FCV-F9 was reduced by 2.87, 3.08, and 3.25 log₁₀ PFU/mL, and high-titer MNV-1 was reduced by 1.55, 2.32, and 2.75 log₁₀ PFU/mL with BAC at 0.1, 0.25, and 0.5 mg/mL, respectively. High-titer MS2 was reduced by ∼2 log₁₀ PFU/mL with BAC at all three concentrations. KPMS at all three concentrations reduced high and low titers of FCV-F9 and MS2 and low-titer MNV-1 to undetectable levels, while high-titer MNV-1 was reduced by 0.92 and 3.44 log₁₀ PFU/mL with KMPS at 2.5 and 5 mg/mL, respectively. TA at 0.2 mg/mL only reduced high-titer FCV-F9 by 0.98 log₁₀ PFU/mL and low-titer FCV-F9 by 1.95 log₁₀ PFU/mL. GA at 0.1, 0.2, and 0.4 mg/mL reduced low-titer FCV-F9 by 2.50, 2.36, and 0.86 log₁₀ PFU/mL, respectively with negligible effects against high-titer FCV-F9. BAC and KPMS show promise to be used as broad-spectrum contact surface disinfectants for prevention of noroviral surrogate contamination.

  15. Norovirus Gastroenteritis in a Birth Cohort in Southern India.

    PubMed

    Menon, Vipin Kumar; George, Santosh; Sarkar, Rajiv; Giri, Sidhartha; Samuel, Prasanna; Vivek, Rosario; Saravanabavan, Anuradha; Liakath, Farzana Begum; Ramani, Sasirekha; Iturriza-Gomara, Miren; Gray, James J; Brown, David W; Estes, Mary K; Kang, Gagandeep

    2016-01-01

    Noroviruses are an important cause of gastroenteritis but little is known about disease and re-infection rates in community settings in Asia. Disease, re-infection rates, strain prevalence and genetic susceptibility to noroviruses were investigated in a birth cohort of 373 Indian children followed up for three years. Stool samples from 1856 diarrheal episodes and 147 vomiting only episodes were screened for norovirus by RT-PCR. Norovirus positivity was correlated with clinical data, secretor status and ABO blood group. Of 1856 diarrheal episodes, 207 (11.2%) were associated with norovirus, of which 49(2.6%) were norovirus GI, 150(8.1%) norovirus GII, and 8 (0.4%) were mixed infections with both norovirus GI and GII. Of the 147 vomiting only episodes, 30 (20.4%) were positive for norovirus in stool, of which 7 (4.8%) were norovirus GI and 23 (15.6%) GII. At least a third of the children developed norovirus associated diarrhea, with the first episode at a median age of 5 and 8 months for norovirus GI and GII, respectively. Norovirus GI.3 and GII.4 were the predominant genotypes (40.3% and 53.0%) with strain diversity and change in the predominant sub-cluster over time observed among GII viruses. A second episode of norovirus gastroenteritis was documented in 44/174 (25.3%) ever-infected children. Children with the G428A homozygous mutation for inactivation of the FUT2 enzyme (se428se428) were at a significantly lower risk (48/190) of infection with norovirus (p = 0.01). This is the first report of norovirus documenting disease, re-infection and genetic susceptibility in an Asian birth cohort. The high incidence and apparent lack of genogroupII specific immunity indicate the need for careful studies on further characterization of strains, asymptomatic infection and shedding and immune response to further our understanding of norovirus infection and disease.

  16. Persistence of human norovirus in reconstituted pesticides--pesticide application as a possible source of viruses in fresh produce chains.

    PubMed

    Verhaelen, Katharina; Bouwknegt, Martijn; Rutjes, Saskia A; de Roda Husman, Ana Maria

    2013-01-01

    The consumption of fresh produce is frequently associated with outbreaks of human norovirus (hNoV) disease. To prevent the contamination of fresh produce with hNoV, knowledge of the possible introduction sources of the viruses, such as water, is needed to be able to implement appropriate and efficient preventive measures. Contaminated water used to reconstitute pesticides could be a relevant source of infectious hNoV, determined by the initial level of virus contamination and the persistence of these viruses in reconstituted pesticides. We studied the persistence of hNoV GI.4, hNoV GII.4 and murine norovirus (MNV-1), the only culturable norovirus, in eight different pesticides after 0 and 2h. Virus concentrations were determined by reverse transcriptase PCR, and infectivity of MNV-1 was determined by endpoint dilutions followed by maximum likelihood estimations. MNV-1 was found to remain infectious in seven of the eight tested pesticides at the highest concentration applied in practice. In the presence of the insecticide Vertimec, MNV-1 infectivity decreased rapidly with a 1.9 log(10)-unit reduction at timepoint T(0). Also, the concentration of NoV GI.4 RNA decreased considerably with a 1.7 log(10)-unit reduction; whereas the detected PCR fragment of hNoV GII.4 remained stable. Assuming a similar persistence of infectious MNV-1 and hNoV we can conclude that water containing hNoV used to dilute pesticides may be an important source of infectious hNoV in fresh produce chains. The application of pesticides may therefore not only be a chemical hazard, but also a microbiological hazard for public health. The inclusion of antiviral substances in reconstituted pesticides may be appropriate to reduce the virological health risk posed by the application of pesticides.

  17. Analysis of norovirus contamination of seafood

    USDA-ARS?s Scientific Manuscript database

    The study of human norovirus (NoVs) replication in vitro would be a highly useful tool to virologists and immunologists. For this reason, we have searched for new approaches to determine viability of noroviruses in food samples (especially sea food). Our research team has multiple years of experie...

  18. Murine Norovirus: Propagation, Quantification and Genetic Manipulation

    PubMed Central

    Hwang, Seungmin; Alhatlani, Bader; Arias, Armando; Caddy, Sarah L; Christodoulou, Constantina; Cunha, Juliana; Emmott, Ed; Gonzalez-Hernandez, Marta; Kolawole, Abimbola; Lu, Jia; Rippinger, Christine; Sorgeloos, Frédéric; Thorne, Lucy; Vashist, Surender; Goodfellow, Ian

    2014-01-01

    Murine norovirus (MNV) is a positive-sense, plus-stranded RNA virus in the Caliciviridae family. It is the most common pathogen in biomedical research colonies. MNV is also related to the human noroviruses, which cause the majority of non-bacterial gastroenteritis worldwide. Like the human noroviruses, MNV is an enteric virus that replicates in the intestine and is transmitted by the fecal-oral route. MNV replicates in murine macrophages and dendritic cells in cells in culture and in the murine host. This virus is often used to study mechanisms in norovirus biology, because the human noroviruses are refractory to growth in cell culture. MNV combines the availability of a cell culture and reverse genetics system with the ability to study infection in the native host. Herein, we describe a panel of techniques that are commonly used to study MNV biology. PMID:24789596

  19. The influence of temperature pH and water immersion on the high hydrostatic pressure inactivation of GI.1 and GII.4 human noroviruses

    USDA-ARS?s Scientific Manuscript database

    Detection of human norovirus (HuNoV) usually relies on molecular biology techniques, such as qRT PCR. Since histo-blood group antigens (HBGAs) are the functional receptors for HuNoV, HuNoV can bind to porcine gastric mucin (PGM), which contains HBGA-like antigens. In this study, PGM conjugated magn...

  20. Bacterial surface-displayed GII.4 human norovirus capsid proteins bound to surface of Romaine lettuce through HBGA-like molecules

    USDA-ARS?s Scientific Manuscript database

    Human Noroviruses (HuNoVs) are the main cause of nonbacterial gastroenteritis. Contaminated produce is a main vehicle for dissemination of HuNoVs. In this study, we used an ice nucleation protein (INP) mediated surface display system to present the protruding domain of GII.4 HuNoV capsid protein (G...

  1. Comparison of nucleic acid extraction and reverse transcription-qPCR approaches for detection of GI and GII noroviruses in drinking water

    EPA Science Inventory

    Noroviruses (NoVs) are responsible for a number of waterborne and foodborne gastroenteritis cases each year. They are frequently associated with human sewage, and thus a potential link between wastewater discharge and contamination of source waters exists. Subsequently, contami...

  2. Comparison of nucleic acid extraction and reverse transcription-qPCR approaches for detection of GI and GII noroviruses in drinking water

    EPA Science Inventory

    Noroviruses (NoVs) are responsible for a number of waterborne and foodborne gastroenteritis cases each year. They are frequently associated with human sewage, and thus a potential link between wastewater discharge and contamination of source waters exists. Subsequently, contami...

  3. Comparison of human saliva and synthetic histo-blood group antigens usage as ligands in norovirus-like particle binding and blocking assays.

    PubMed

    Uusi-Kerttula, Hanni; Tamminen, Kirsi; Malm, Maria; Vesikari, Timo; Blazevic, Vesna

    2014-06-01

    Blocking of norovirus-like particle binding to their cellular ligands, histo-blood group antigens with immune sera, is considered a surrogate norovirus neutralization assay. We compared human secretor positive saliva and synthetic biotinylated carbohydrates as a source of histo-blood group antigens in binding and blocking assays. Six norovirus capsid-derived virus-like particles belonging to genogroup I (GI-1-2001 and GI-3-2002) and genogroup II (GII-4-1999, GII-4-2010 New Orleans, GII-4-2012 Sydney and GII-12-1998) noroviruses were produced by a recombinant baculovirus expression system and binding profile to saliva type A, B and O and to synthetic antigens (A trimer, B trimer, H type 1, H type 3, Lewis(a) and Lewis(b)) was identified. Good correlation between virus-like particle binding to saliva type A and synthetic A trimer (r = 0.66, p < 0.05) and saliva type B and synthetic B trimer (r = 0.75, p < 0.05) was observed. Binding of each norovirus virus-like particle to the selected histo-blood group antigens was blocked by convalescent sera from NoV-infected subjects or type-specific mouse antisera. Our results support the use of either saliva or synthetic antigens in blocking assay to measure the ability of norovirus antisera to block virus-like particle binding to the carbohydrate ligands. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  4. Preclinical Dose Ranging Studies of a Novel Dry Powder Norovirus Vaccine Formulation

    PubMed Central

    Springer, Michael J.; Ni, Yawei; Finger-Baker, Isaac; Ball, Jordan P.; Hahn, Jessica; DiMarco, Ashley V.; Kobs, Dean; Horne, Bobbi; Talton, James D.; Cobb, Ronald R.

    2016-01-01

    Norovirus is the primary cause of viral gastroenteritis in humans with multiple genotypes currently circulating worldwide. The development of a successful norovirus vaccine is contingent on its ability to induce both systemic and mucosal antibody responses against a wide range of norovirus genotypes. Norovirus virus like particles (VLPs) are known to elicit systemic and mucosal immune responses when delivered intranasally. Incorporation of these VLPs into an intranasal powder vaccine offers the advantage of simplicity and induction of neutralizing systemic and mucosal antibodies. Nasal immunization, which provides the advantage of ease of administration and a mucosal delivery mechanism, faces the real issue of limited nasal residence time due to mucociliary clearance. Herein, we describe a novel dry powder (GelVac™) formulation of GI or GII.4 norovirus VLPs, two dominant circulating genotypes, to identify the optimal antigen dosages based on systemic and mucosal immune responses in guinea pigs. Systemic and mucosal immunogenicity of each of the VLPs was observed in a dose dependant manner. In addition, a boosting effect was observed after the second dosing of each VLP antigen. With the GelVac™ formulation, a total antigen dose of ≥15 µg was determined to be the maximally immunogenic dose for both GI and GII.4 norovirus VLP based on evaluation for 56 days. Taken together, these results indicate that norovirus VLPs could be used as potential vaccine candidates without using an immunostimilatory adjuvant and provides a basis for the development of a GelVac™ bivalent GI/GII.4 norovirus VLP vaccine. PMID:26873053

  5. Bovine noroviruses: A missing component of calf diarrhoea diagnosis.

    PubMed

    Di Felice, Elisabetta; Mauroy, Axel; Pozzo, Fabiana Dal; Thiry, Damien; Ceci, Chiara; Di Martino, Barbara; Marsilio, Fulvio; Thiry, Etienne

    2016-01-01

    Noroviruses are RNA viruses that belong to the Genus Norovirus, Family Caliciviridae, and infect human beings and several animal species, including cattle. Bovine norovirus infections have been detected in cattle of a range of different ages throughout the world. Currently there is no suitable cell culture system for these viruses and information on their pathogenesis is limited. Molecular and serological tests have been developed, but are complicated by the high genetic and antigenic diversity of bovine noroviruses. Bovine noroviruses can be detected frequently in faecal samples of diarrhoeic calves, either alone or in association with other common enteric pathogens, suggesting a role for these viruses in the aetiology of calf enteritis.

  6. Effects of Abiotic and Biotic Stresses on the Internalization and Dissemination of Human Norovirus Surrogates in Growing Romaine Lettuce

    PubMed Central

    DiCaprio, Erin; Purgianto, Anastasia

    2015-01-01

    Human norovirus (NoV) is the major causative agent of fresh-produce-related outbreaks of gastroenteritis; however, the ecology and persistence of human NoV in produce systems are poorly understood. In this study, the effects of abiotic and biotic stresses on the internalization and dissemination of two human NoV surrogates (murine norovirus 1 [MNV-1] and Tulane virus [TV]) in romaine lettuce were determined. To induce abiotic stress, romaine lettuce was grown under drought and flood conditions that mimic extreme weather events, followed by inoculation of soil with MNV-1 or TV. Independently, lettuce plants were infected with lettuce mosaic virus (LMV) to induce biotic stress, followed by inoculation with TV. Plants were grown for 14 days, and viral titers in harvested tissues were determined by plaque assays. It was found that drought stress significantly decreased the rates of both MNV-1 and TV internalization and dissemination. In contrast, neither flood stress nor biotic stress significantly impacted viral internalization or dissemination. Additionally, the rates of TV internalization and dissemination in soil-grown lettuce were significantly higher than those for MNV-1. Collectively, these results demonstrated that (i) human NoV surrogates can be internalized via roots and disseminated to shoots and leaves of romaine lettuce grown in soil, (ii) abiotic stress (drought) but not biotic stress (LMV infection) affects the rates of viral internalization and dissemination, and (iii) the type of virus affects the efficiency of internalization and dissemination. This study also highlights the need to develop effective measures to eliminate internalized viruses in fresh produce. PMID:25956773

  7. Effects of Abiotic and Biotic Stresses on the Internalization and Dissemination of Human Norovirus Surrogates in Growing Romaine Lettuce.

    PubMed

    DiCaprio, Erin; Purgianto, Anastasia; Li, Jianrong

    2015-07-01

    Human norovirus (NoV) is the major causative agent of fresh-produce-related outbreaks of gastroenteritis; however, the ecology and persistence of human NoV in produce systems are poorly understood. In this study, the effects of abiotic and biotic stresses on the internalization and dissemination of two human NoV surrogates (murine norovirus 1 [MNV-1] and Tulane virus [TV]) in romaine lettuce were determined. To induce abiotic stress, romaine lettuce was grown under drought and flood conditions that mimic extreme weather events, followed by inoculation of soil with MNV-1 or TV. Independently, lettuce plants were infected with lettuce mosaic virus (LMV) to induce biotic stress, followed by inoculation with TV. Plants were grown for 14 days, and viral titers in harvested tissues were determined by plaque assays. It was found that drought stress significantly decreased the rates of both MNV-1 and TV internalization and dissemination. In contrast, neither flood stress nor biotic stress significantly impacted viral internalization or dissemination. Additionally, the rates of TV internalization and dissemination in soil-grown lettuce were significantly higher than those for MNV-1. Collectively, these results demonstrated that (i) human NoV surrogates can be internalized via roots and disseminated to shoots and leaves of romaine lettuce grown in soil, (ii) abiotic stress (drought) but not biotic stress (LMV infection) affects the rates of viral internalization and dissemination, and (iii) the type of virus affects the efficiency of internalization and dissemination. This study also highlights the need to develop effective measures to eliminate internalized viruses in fresh produce. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  8. Type I and Type II Interferons Inhibit the Translation of Murine Norovirus Proteins▿

    PubMed Central

    Changotra, Harish; Jia, Yali; Moore, Tara N.; Liu, Guangliang; Kahan, Shannon M.; Sosnovtsev, Stanislav V.; Karst, Stephanie M.

    2009-01-01

    Human noroviruses are responsible for more than 95% of nonbacterial epidemic gastroenteritis worldwide. Both onset and resolution of disease symptoms are rapid, suggesting that components of the innate immune response are critical in norovirus control. While the study of the human noroviruses has been hampered by the lack of small animal and tissue culture systems, our recent discovery of a murine norovirus (MNV) and its in vitro propagation have allowed us to begin addressing norovirus replication strategies and immune responses to norovirus infection. We have previously demonstrated that interferon responses are critical to control MNV-1 infection in vivo and to directly inhibit viral replication in vitro. We now extend these studies to define the molecular basis for interferon-mediated inhibition. Viral replication intermediates were not detected in permissive cells pretreated with type I interferon after either infection or transfection of virion-associated RNA, demonstrating a very early block to virion production that is after virus entry and uncoating. A similar absence of viral replication intermediates was observed in infected primary macrophages and dendritic cells pretreated with type I IFN. This was not due to degradation of incoming genomes in interferon-pretreated cells since similar levels of genomes were present in untreated and pretreated cells through 6 h of infection, and these genomes retained their integrity. Surprisingly, this block to the translation of viral proteins was not dependent on the well-characterized interferon-induced antiviral molecule PKR. Similar results were observed in cells pretreated with type II interferon, except that the inhibition of viral translation was dependent on PKR. Thus, both type I and type II interferon signaling inhibit norovirus translation in permissive myeloid cells, but they display distinct dependence on PKR for this inhibition. PMID:19297466

  9. Molecular epidemiology of norovirus in South Korea

    PubMed Central

    Lee, Sung-Geun; Cho, Han-Gil; Paik, Soon-Young

    2015-01-01

    Norovirus is a major cause of viral gastroenteritis and a common cause of foodborne and waterborne outbreaks. Norovirus outbreaks are responsible for economic losses, most notably to the public health and food industry field. Norovirus has characteristics such as low infectious dose, prolonged shedding period, strong stability, great diversity, and frequent genome mutations. Besides these characteristics, they are known for rapid and extensive spread in closed settings such as hospitals, hotels, and schools. Norovirus is well known as a major agent of food-poisoning in diverse settings in South Korea. For these reasons, nationwide surveillance for norovirus is active in both clinical and environmental settings in South Korea. Recent studies have reported the emergence of variants and novel recombinants of norovirus. In this review, we summarized studies on the molecular epidemiology and nationwide surveillance of norovirus in South Korea. This review will provide information for vaccine development and prediction of new emerging variants of norovirus in South Korea. [BMB Reports 2015; 48(2): 61-67] PMID:25441425

  10. Norovirus recombination.

    PubMed

    Bull, Rowena A; Tanaka, Mark M; White, Peter A

    2007-12-01

    RNA recombination is a significant driving force in viral evolution. Increased awareness of recombination within the genus Norovirus of the family Calicivirus has led to a rise in the identification of norovirus (NoV) recombinants and they are now reported at high frequency. Currently, there is no classification system for recombinant NoVs and a widely accepted recombinant genotyping system is still needed. Consequently, there is duplication in reporting of novel recombinants. This has led to difficulties in defining the number and types of recombinants in circulation. In this study, 120 NoV nucleotide sequences were compiled from the current GenBank database and published literature. NoV recombinants and their recombination breakpoints were identified using three methods: phylogenetic analysis, SimPlot analysis and the maximum chi2 method. A total of 20 NoV recombinant types were identified in circulation worldwide. The recombination point is the ORF1/2 overlap in all isolates except one, which demonstrated a double recombination event within the polymerase region.

  11. In Vivo Comparison of Two Human Norovirus Surrogates for Testing Ethanol-Based Handrubs: The Mouse Chasing the Cat!

    PubMed Central

    Sattar, Syed A.; Ali, Mohammad; Tetro, Jason A.

    2011-01-01

    Human noroviruses (HuNoV), a major cause of acute gastroenteritis worldwide, cannot be readily cultured in the lab. Therefore, a feline calicivirus (FCV) is often used as its surrogate to, among other things, test alcohol-based handrubs (ABHR). The more recent laboratory culture of a mouse norovirus (MNV) provides an alternative. While MNV is closer to HuNoV in several respects, to date, no comparative testing of FCV and MNV survival and inactivation on human hands has been performed. This study was designed to address the knowledge gap. The rates of loss in viability during drying on hands were −1.91 and −1.65% per minute for FCV and MNV, respectively. When the contaminated skin was exposed for 20 s to either a commercial ABHR with 62% (v/v) ethanol or to 75% (v/v) ethanol in water, FCV infectivity was reduced by <1 log10 while that of MNV by nearly 2.8 log10. Extending the contact time to 30 s reduced the FCV titer by almost 2 log10 by both test substances and that of MNV by >3.5 log10 by the commercial ABHR while 75% ethanol did not show any noticeable improvement in activity as compared to the 20 s contact. An 80% (v/v) aqueous solution of ethanol gave only a 1.75 log10 reduction in MNV activity after 20 s. The results show significant differences in the ethanol susceptibility of FCV and MNV in contact times relevant to field use of ABHR and also that 62% ethanol was a more effective virucide than either 75% or 80% ethanol. These findings indicate the need for a review of the continuing use of FCV as a surrogate for HuNoV. PMID:21390325

  12. Evaluation of Chlorine Treatment Levels on Inactivation of Human Norovirus and MS2 Bacteriophage during Sewage Treatment.

    PubMed

    Kingsley, David H; Fay, Johnna P; Calci, Kevin; Pouillot, Régis; Woods, Jacquelina; Chen, Haiqiang; Niemira, Brendan A; Van Doren, Jane M

    2017-09-22

    This study examined the inactivation of human norovirus (HuNoV) GI.1 and GII.4 by chlorine under conditions that mimic sewage treatment. Using a porcine gastric mucin-magnetic bead (PGM-MB) assay, no statistically significant loss in HuNoV binding (inactivation) was observed for secondary effluent treatments of ≤25 ppm total chlorine, while for both strains 50 and 100 ppm treatments resulted in ≤0.8 log10 and ≥3.9 log10 reductions, respectively. Treatments of 10, 25, 50, and 100 ppm chlorine inactivated 0.31, 1.35, >5, and >5 log10 of the norovirus indicator, MS2 bacteriophage, respectively. Evaluation of treatment time indicated that the vast majority of MS2 and HuNoV inactivation occurred in the first 5 min for 0.2-μm filtered, pre-chlorinated secondary effluent. Free chlorine measurements of secondary effluent seeded with MS2 and HuNoV demonstrated a substantial oxidative burden. For 25, 50, and 100 ppm treatments, free chlorine after 5 min exposure time ranged between 0.21-0.58, 0.28-16.7, and 11.6-53 ppm, respectively. At chlorine treatment levels of >50 ppm, statistically significant differences were observed between reductions for PGM-MB-bound HuNoV (potentially infectious) particles as compared with that for unbound (non-infectious) HuNoV particles or total norovirus particles. While results suggest that MS2 and HuNoV (as measured with PGM-MB binding) behave similarly, although not identically, both have limited susceptibility to chlorine treatments of ≤ 25 ppm total chlorine. Since sewage treatment is performed at ≤ 25 ppm total chlorine, targeting a free chlorine level of 0.5-1.0 ppm, these results suggest that traditional chlorine-based sewage treatment does not inactivate HuNoV efficiently.IMPORTANCE HuNoV is ubiquitous in sewage. A receptor binding assay was used to assess inactivation of HuNoV by chlorine-based sewage treatment given that the virus cannot be routinely propagated in vitro Results reported here indicate that chlorine

  13. Inactivation of Human Norovirus GI, GII, and Surrogates by Free Chlorine in Postharvest Leafy Green Wash Water.

    PubMed

    Dunkin, Nathan; Weng, Shih-Chi; Jacangelo, Joseph G; Schwab, Kellogg J

    2017-09-08

    Human noroviruses (hNoVs) are a known public health concern associated with the consumption of leafy green vegetables. While a number of studies have investigated pathogen reduction on the surfaces of leafy greens during the postharvest washing process, there remains a paucity of data on the level of treatment needed to inactivate viruses in the wash water, which is critical for preventing cross-contamination. The objective of this study was to quantify the susceptibility of hNoV GI, hNoV GII, murine norovirus (MNV), and bacteriophage MS2 to free chlorine in whole leaf, chopped romaine, and shredded iceberg lettuce industrial leafy green wash waters, each sampled three times over a 4-month period. A suite of kinetic inactivation models was fit to the viral reduction data to aid in quantification of concentration × time (CT) values. Results indicate that 3 log10 infectivity reduction was achieved at CT values of less than 0.2 mg-min/L for MNV and 2.5 mg-min/L for MS2 in all wash water types. CT values for 2 log10 molecular reduction of hNoV GI in whole leaf and chopped romaine wash waters were 1.5 and 0.9 mg-min/L, respectively. For hNoV GII, CT values were 13.0 and 7.5 mg-min/L, respectively. In shredded iceberg wash water, 3 log10 molecular reduction was not observed for any virus over the time course of experiments. These findings demonstrate that noroviruses may exhibit genogroup dependent resistance to free chlorine and emphasize the importance of distinguishing between genogroups in hNoV persistence studies.Importance Postharvest washing of millions of pounds of leafy greens is performed daily in industrial processing facilities with the intention of removing dirt, debris, and pathogenic microorganisms prior to packaging. Modest inactivation of pathogenic microorganisms (less than 1-2 log10) is known to occur on the surfaces of leafy greens during washing. Therefore, the primary purpose of the sanitizing agent is to maintain microbial quality of postharvest

  14. Reduction of Human Norovirus GI, GII, and Surrogates by Peracetic Acid and Monochloramine in Municipal Secondary Wastewater Effluent.

    PubMed

    Dunkin, Nathan; Weng, ShihChi; Coulter, Caroline G; Jacangelo, Joseph G; Schwab, Kellogg J

    2017-09-27

    The objective of this study was to characterize human norovirus (hNoV) GI and GII reductions during disinfection by peracetic acid (PAA) and monochloramine in secondary wastewater (WW) and phosphate buffer (PB) as assessed by reverse transcription-qPCR (RT-qPCR). Infectivity and RT-qPCR reductions are also presented for surrogate viruses murine norovirus (MNV) and bacteriophage MS2 under identical experimental conditions to aid in interpretation of hNoV molecular data. In WW, RT-qPCR reductions were less than 0.5 log10 for all viruses at concentration-time (CT) values up to 450 mg-min/L except for hNoV GI, where 1 log10 reduction was observed at CT values of less than 50 mg-min/L for monochloramine and 200 mg-min/L for PAA. In PB, hNoV GI and MNV exhibited comparable resistance to PAA and monochloramine with CT values for 2 log10 RT-qPCR reduction between 300 and 360 mg-min/L. Less than 1 log10 reduction was observed for MS2 and hNoV GII in PB at CT values for both disinfectants up to 450 mg-min/L. Our results indicate that hNoVs exhibit genogroup dependent resistance and that disinfection practices targeting hNoV GII will result in equivalent or greater reductions for hNoV GI. These data provide valuable comparisons between hNoV and surrogate molecular signals that can begin the process of informing regulators and engineers on WW treatment plant design and operational practices necessary to inactivate hNoVs.

  15. Destruction of the Capsid and Genome of GII.4 Human Norovirus Occurs during Exposure to Metal Alloys Containing Copper

    PubMed Central

    Manuel, C. S.; Moore, M. D.

    2015-01-01

    Human norovirus (HuNoV) represents a significant public health burden worldwide and can be environmentally transmitted. Copper surfaces have been shown to inactivate the cultivable surrogate murine norovirus, but no such data exist for HuNoV. The purpose of this study was to characterize the destruction of GII.4 HuNoV and virus-like particles (VLPs) during exposure to copper alloy surfaces. Fecal suspensions positive for a GII.4 HuNoV outbreak strain or GII.4 VLPs were exposed to copper alloys or stainless steel for 0 to 240 min and recovered by elution. HuNoV genome integrity was assessed by reverse transcription-quantitative PCR (RT-qPCR) (without RNase treatment), and capsid integrity was assessed by RT-qPCR (with RNase treatment), transmission electron microscopy (TEM), SDS-PAGE/Western blot analysis, and a histo-blood group antigen (HBGA) binding assay. Exposure of fecal suspensions to pure copper for 60 min reduced the GII.4 HuNoV RNA copy number by ∼3 log10 units when analyzed by RT-qPCR without RNase treatment and by 4 log10 units when a prior RNase treatment was used. The rate of reduction of the HuNoV RNA copy number was approximately proportional to the percentage of copper in each alloy. Exposure of GII.4 HuNoV VLPs to pure-copper surfaces resulted in noticeable aggregation and destruction within 240 min, an 80% reduction in the VP1 major capsid protein band intensity in 15 min, and a near-complete loss of HBGA receptor binding within 8 min. In all experiments, HuNoV remained stable on stainless steel. These results suggest that copper surfaces destroy HuNoV and may be useful in preventing environmental transmission of the virus in at-risk settings. PMID:25979897

  16. Destruction of the Capsid and Genome of GII.4 Human Norovirus Occurs during Exposure to Metal Alloys Containing Copper.

    PubMed

    Manuel, C S; Moore, M D; Jaykus, L A

    2015-08-01

    Human norovirus (HuNoV) represents a significant public health burden worldwide and can be environmentally transmitted. Copper surfaces have been shown to inactivate the cultivable surrogate murine norovirus, but no such data exist for HuNoV. The purpose of this study was to characterize the destruction of GII.4 HuNoV and virus-like particles (VLPs) during exposure to copper alloy surfaces. Fecal suspensions positive for a GII.4 HuNoV outbreak strain or GII.4 VLPs were exposed to copper alloys or stainless steel for 0 to 240 min and recovered by elution. HuNoV genome integrity was assessed by reverse transcription-quantitative PCR (RT-qPCR) (without RNase treatment), and capsid integrity was assessed by RT-qPCR (with RNase treatment), transmission electron microscopy (TEM), SDS-PAGE/Western blot analysis, and a histo-blood group antigen (HBGA) binding assay. Exposure of fecal suspensions to pure copper for 60 min reduced the GII.4 HuNoV RNA copy number by ∼3 log10 units when analyzed by RT-qPCR without RNase treatment and by 4 log10 units when a prior RNase treatment was used. The rate of reduction of the HuNoV RNA copy number was approximately proportional to the percentage of copper in each alloy. Exposure of GII.4 HuNoV VLPs to pure-copper surfaces resulted in noticeable aggregation and destruction within 240 min, an 80% reduction in the VP1 major capsid protein band intensity in 15 min, and a near-complete loss of HBGA receptor binding within 8 min. In all experiments, HuNoV remained stable on stainless steel. These results suggest that copper surfaces destroy HuNoV and may be useful in preventing environmental transmission of the virus in at-risk settings.

  17. Pressure inactivation of Tulane virus, a candidate surrogate for human norovirus and its potential application in food industry.

    PubMed

    Li, Xinhui; Ye, Mu; Neetoo, Hudaa; Golovan, Serguei; Chen, Haiqiang

    2013-03-01

    Human norovirus (HuNoV) is the leading causative agent for foodborne disease. Currently, studies of HuNoV usually rely on surrogates such as murine norovirus (MNV) due to the lack of a suitable cell culture system and a small animal model for HuNoV. Tulane virus (TV), a monkey calicivirus, is a cultivable enteric calicivirus that not only recognizes the same receptors as HuNoV, but is also genetically closely related to HuNoV. In this study, we determined the pH stability of TV and MNV-1, as well as the effect of high hydrostatic pressure (HHP) on inactivating both viruses in aqueous media, blueberries and oysters. We demonstrated that both TV and MNV-1 were very stable under an acidic environment. They were more resistant to pressure at an acidic environment than at neutral pH. Pressure treatment of 600 MPa for 2 min at different temperatures (4, 21 and 35 °C) barely caused any reduction of TV, as well as MNV-1, on un-wetted (dry) blueberries. However, both TV and MNV-1 on blueberries were successfully inactivated by a pressure of ≤400 MPa when blueberries were immersed in phosphate-buffered saline during HHP. Pressure inactivation of both TV and MNV-1 in blueberries and oysters increased as sample temperature decreased in the order of 4>21>35 °C. TV was more sensitive to pressure than MNV-1 for the three matrices tested, culture media, blueberries and oysters. This study provides important information on the use of TV as a surrogate for HuNoV study. Results obtained from this study lay a foundation for designing effective HHP treatments for inactivation of HuNoV in high-risk foods such as berries and oysters. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Solar water disinfection (SODIS): Impact on hepatitis A virus and on a human Norovirus surrogate under natural solar conditions.

    PubMed

    Polo, David; García-Fernández, Irene; Fernández-Ibáñez, Pilar; Romalde, Jesús L

    2015-03-01

    This study evaluates the effectiveness of solar water disinfection (SODIS) in the reduction and inactivation of hepatitis A virus (HAV) and of the human Norovirus surrogate, murine Norovirus (MNV-1), under natural solar conditions. Experiments were performed in 330 ml polyethylene terephthalate (PET) bottles containing HAV or MNV-1 contaminated waters (10(3) PFU/ml) that were exposed to natural sunlight for 2 to 8 h. Parallel experiments under controlled temperature and/or in darkness conditions were also included. Samples were concentrated by electropositive charged filters and analysed by RT-real time PCR (RT-qPCR) and infectivity assays. Temperature reached in bottles throughout the exposure period ranged from 22 to 40ºC. After 8 h of solar exposure (cumulative UV dose of ~828 kJ/m2 and UV irradiance of ~20 kJ/l), the results showed significant (P<0.05) reductions from 4.0 (+/-0.56)x10(4) to 3.15 (+/-0.69)x10(3) RNA copies/100ml (92.1%, 1.1 log) for HAV and from 5.91 (+/-0.59)x10(4) to 9.24 (+/-3.91)x10(3) RNA copies/100 ml (84.4%, 0.81 log) for MNV-1. SODIS conditions induced a loss of infectivity between 33.4% and 83.4% after 4 to 8 h in HAV trials, and between 33.4% and 66.7% after 6 h to 8 h in MNV-1 trials. The results obtained indicated a greater importance of sunlight radiation over the temperature as the main factor for viral reduction.

  19. Norovirus Transmission on Cruise Ship

    PubMed Central

    Isakbaeva, Elmira T.; Beard, R. Suzanne; Bulens, Sandra N.; Mullins, James; Monroe, Stephan S.; Bresee, Joseph; Sassano, Patricia; Cramer, Elaine H.; Glass, Roger I.

    2005-01-01

    We describe an investigation of a norovirus gastroenteritis outbreak aboard a cruise ship affecting 6 consecutive cruises and the use of sequence analysis to determine modes of virus transmission. Noroviruses (NoV), are the most common cause of infectious acute gastroenteritis and are transmitted feco-orally through food and water, directly from person to person and by environmental contamination (1). These viruses are often responsible for protracted outbreaks in closed settings, such as cruise ships, nursing homes, and hospitals (2,3). PMID:15705344

  20. Immunogenicity and Specificity of Norovirus Consensus GII.4 Virus-like Particles in Monovalent and Bivalent Vaccine Formulations

    PubMed Central

    Parra, Gabriel I.; Bok, Karin; Taylor, Ross; Haynes, Joel; Sosnovtsev, Stanislav V.; Richardson, Charles; Green, Kim Y.

    2012-01-01

    Noroviruses, a major cause of acute gastroenteritis worldwide, present antigenic diversity that must be considered for the development of an effective vaccine. In this study, we explored approaches to increase the broad reactivity of virus-like particle (VLP) norovirus vaccine candidates. The immunogenicity of a GII.4 “Consensus” VLP that was engineered from sequences of three genetically distinct naturally-occurring GII.4 strains was examined for its ability to induce cross-reactive immune responses against different clusters of GII.4 noroviruses. Rabbits immunized with GII.4 Consensus VLPs developed high serum antibody titers against VLPs derived from a number of distinct wild-type GII.4 viruses, including some that have been circulating over 30 years. Because the sera exhibited low cross-reactivity with antigenically-distinct GI norovirus strains, we investigated the serum antibody response to a bivalent vaccine formulation containing GI.1 (Norwalk virus) and GII.4 Consensus VLPs that was administered to animals under varying conditions. In these studies, the highest homologous and heterologous antibody titers to the bivalent vaccine were elicited following immunization of animals by the intramuscular route using Alhydrogel (Al(OH)3) as adjuvant. Our data indicate that the use of both genetically-engineered norovirus VLPs that incorporate relevant epitopes from multiple strains and multivalent vaccine formulations increase the breadth of the immune response to diverse variants within a genotype and, thus, prove helpful in the rational design of VLP-based vaccines against human noroviruses. PMID:22469864

  1. Detection and molecular characterization of human noroviruses in Korean groundwater between 2008 and 2010.

    PubMed

    Lee, Gyu-Cheol; Jheong, Weon-Hwa; Jung, Gyoo Seung; Oh, Sung-Ae; Kim, Min-jeong; Rhee, Ok-Jae; Park, Sujeong; Lee, Chan Hee

    2012-09-01

    RT-PCR, nucleotide sequencing, and phylogenetic analysis were performed for genotyping and molecular characterization of noroviruses isolated from Korean groundwater. Among 160 samples collected from 80 sites between 2008 and 2010, 14 samples (8.7 %) from 12 sites were positive for noroviruses (NoVs). The percentages of NoV-positive samples in 2008, 2009, and 2010 were 22.2, 3.2, and 0 %, respectively, representing a yearly decrease. GII-positive samples (n = 9, 5.6 %) outnumbered GI-positive samples (n = 5, 3.1 %). The genotypes of the GI NoVs were GI.2, GI.5, and GI.6, and the genotypes of the GII NoVs were all GII.4. One sample, HM623465, was very similar to CUK-3 and CBNU2 and two GII.4 sequences isolated from the stool of Korean gastroenteritis patients. A BLASTN search revealed several nucleotide sequences highly similar to those of NoVs isolated in this study. The original isolation sources for these similar NoVs were mostly stool (n = 731, 80.0 %) and groundwater (n = 135, 14.8 %), and all the countries from which they were isolated were almost in Asia (96.0 %); specifically, China (n = 192, 21.0 %), Japan (n = 383, 41.9 %), Korea (n = 296, 32.4 %), and other Asian countries (n = 6, 0.7 %). These results suggest that Korean groundwater might be contaminated with NoVs from the stool of infected patients and that these NoVs in turn cause new cases of gastroenteritis through a typical fecal-oral route with region-specific circulation. Therefore, it is important to properly treat sewage, which may include waterborne viruses and manage point sources in groundwater for national health and sanitation. In addition, continuous molecular surveillance remains important for understanding circulating NoVs.

  2. A Review of State Licensing Regulations to Determine Alignment with Best Practices to Prevent Human Norovirus Infections in Child-Care Centers.

    PubMed

    Leone, Cortney M; Jaykus, Lee-Ann; Cates, Sheryl M; Fraser, Angela M

    2016-01-01

    Close, frequent contact between children and care providers in child-care centers presents many opportunities to spread human noroviruses. We compared state licensing regulations for child-care centers with national guidelines written to prevent human noroviruses. We reviewed child-care licensing regulations for all 50 U.S. states and the District of Columbia in effect in June 2015 to determine if these regulations fully, partially, or did not address 14 prevention practices in four topic areas: (1) hand hygiene, (2) exclusion of ill people, (3) environmental sanitation, and (4) diapering. Approximately two-thirds (8.9) of the 14 practices across all state regulations were partially or fully addressed, with few (2.6) fully addressed. Practices related to exclusion of ill people and diapering were fully addressed most often, while practices related to hand hygiene and environmental sanitation were fully addressed least often. Regulations based on guidelines for best practices are one way to prevent the spread of human noroviruses in child-care facilities, if the regulations are enforced. Our findings show that, in mid-2015, many state child-care regulations did not fully address these guidelines, suggesting the need to review these regulations to be sure they are based on best practices.

  3. Relevance of F-Specific RNA Bacteriophages in Assessing Human Norovirus Risk in Shellfish and Environmental Waters

    PubMed Central

    Hartard, C.; Banas, S.; Loutreul, J.; Rincé, A.; Benoit, F.; Boudaud, N.

    2016-01-01

    ABSTRACT Human noroviruses (HuNoVs) are the main cause of shellfish-borne gastroenteritis outbreaks. In the absence of routine technical approaches allowing infectious particles to be detected, this viral pathogen is currently targeted by genome research, leading to difficult interpretations. In this study, we investigated the potential of F-specific RNA bacteriophages (FRNAPH) as fecal and viral contamination indicators in shellfish and water from a local harvesting area. FRNAPH were also used as microbial source tracking tools. Constraints imposed by detection limits are illustrated here by the detection of infectious FRNAPH in several samples in the absence of FRNAPH genomes. The opposite situation was also observed, likely explained by the persistence of the genomes being greater than infectivity. Similar considerations may be applied to HuNoVs, suggesting that HuNoV genome targeting is of limited relevance in assessing infectious risks. While FRNAPH did not provide any benefits compared to Escherichia coli as fecal pollution indicators in water, novel observations were made in shellfish: contrary to E. coli, a seasonal trend of infectious FRNAPH concentrations was observed. These concentrations were higher than those found in water, confirming bioaccumulation in shellfish. This study also underlines a relationship between the presence of HuNoV genomes and those of human-specific FRNAPH subgroup II (FRNAPH-II) in shellfish collected throughout Europe. Further research should be undertaken to evaluate FRNAPH potential as an indicator of the presence of infectious HuNoVs. To this end, shellfish involved in HuNoV-caused gastroenteritis outbreaks should be analyzed for the presence of infectious FRNAPH-II. IMPORTANCE This work provides new data about the use of F-specific RNA phages (FRNAPH) as a tool for evaluating fecal or viral contamination, especially in shellfish. In our case study, FRNAPH did not provide any benefits compared to E. coli as fecal pollution

  4. Recognition of Histo-Blood Group Antigen-Like Carbohydrates in Lettuce by Human GII.4 Norovirus

    PubMed Central

    Gao, Xiang; Esseili, Malak A.; Lu, Zhongyan; Saif, Linda J.

    2016-01-01

    ABSTRACT Human norovirus (HuNoV) genogroup II genotype 4 (GII.4) strains account for about 80% of the gastroenteritis outbreaks in the United States. Contaminated food is a major transmission vehicle for this virus. In humans, pigs, and oysters, histo-blood group antigens (HBGAs) act as attachment factors for HuNoVs. In lettuce, although the virus-like particles (VLPs) of a GII.4 HuNoV were found to bind to cell wall carbohydrates, the exact binding site has not been investigated. Here, we show the presence of HBGA-like carbohydrates in the cell wall of lettuce. The digestion of lettuce leaves with cell wall-degrading enzymes exposed more binding sites and significantly increased the level of binding of GII.4 HuNoV VLPs. Competition assays showed that both the HBGA monoclonal antibody, recognizing the H type, and plant lectins, recognizing α-l-fucose in the H type, effectively inhibited VLP binding to lettuce tissues. Lettuce cell wall components were isolated and their NoV VLP binding characteristics were tested by enzyme-linked immunosorbent assays. The binding was inhibited by pretreatment of the lettuce cell wall materials with α-1,2-fucosidase. Collectively, our results indicate that H-type HBGA-like carbohydrates exist in lettuce tissues and that GII.4 HuNoV VLPs can bind the exposed fucose moiety, possibly in the hemicellulose component of the cell wall. IMPORTANCE Salad crops and fruits are increasingly recognized as vehicles for human norovirus (HuNoV) transmission. A recent study showed that HuNoVs specifically bind to the carbohydrates of the lettuce cell wall. Histo-blood group antigens (HBGAs) are carbohydrates and are known as the attachment factors for HuNoV infection in humans. In this study, we show the presence of HBGA-like carbohydrates in lettuce, to which HuNoVs specifically bind. These results suggest that specifically bound HuNoVs cannot be removed by simple washing, which may allow viral transmission to consumers. Our findings provide new

  5. Recognition of Histo-Blood Group Antigen-Like Carbohydrates in Lettuce by Human GII.4 Norovirus.

    PubMed

    Gao, Xiang; Esseili, Malak A; Lu, Zhongyan; Saif, Linda J; Wang, Qiuhong

    2016-05-15

    Human norovirus (HuNoV) genogroup II genotype 4 (GII.4) strains account for about 80% of the gastroenteritis outbreaks in the United States. Contaminated food is a major transmission vehicle for this virus. In humans, pigs, and oysters, histo-blood group antigens (HBGAs) act as attachment factors for HuNoVs. In lettuce, although the virus-like particles (VLPs) of a GII.4 HuNoV were found to bind to cell wall carbohydrates, the exact binding site has not been investigated. Here, we show the presence of HBGA-like carbohydrates in the cell wall of lettuce. The digestion of lettuce leaves with cell wall-degrading enzymes exposed more binding sites and significantly increased the level of binding of GII.4 HuNoV VLPs. Competition assays showed that both the HBGA monoclonal antibody, recognizing the H type, and plant lectins, recognizing α-l-fucose in the H type, effectively inhibited VLP binding to lettuce tissues. Lettuce cell wall components were isolated and their NoV VLP binding characteristics were tested by enzyme-linked immunosorbent assays. The binding was inhibited by pretreatment of the lettuce cell wall materials with α-1,2-fucosidase. Collectively, our results indicate that H-type HBGA-like carbohydrates exist in lettuce tissues and that GII.4 HuNoV VLPs can bind the exposed fucose moiety, possibly in the hemicellulose component of the cell wall. Salad crops and fruits are increasingly recognized as vehicles for human norovirus (HuNoV) transmission. A recent study showed that HuNoVs specifically bind to the carbohydrates of the lettuce cell wall. Histo-blood group antigens (HBGAs) are carbohydrates and are known as the attachment factors for HuNoV infection in humans. In this study, we show the presence of HBGA-like carbohydrates in lettuce, to which HuNoVs specifically bind. These results suggest that specifically bound HuNoVs cannot be removed by simple washing, which may allow viral transmission to consumers. Our findings provide new information needed

  6. Norovirus: targets and tools in antiviral drug discovery.

    PubMed

    Rocha-Pereira, Joana; Neyts, Johan; Jochmans, Dirk

    2014-09-01

    The development of antiviral strategies to treat or prevent norovirus infections is a pressing matter. Noroviruses are the number 1 cause of acute gastroenteritis, of foodborne illness, of sporadic gastroenteritis in all age groups and of severe acute gastroenteritis in children less than 5 years old seeking medical assistance [USA/CDC]. In developing countries, noroviruses are linked to significant mortality (~200,000 children <5 years old). Noroviruses are a major culprit for the closure of hospital wards, and associated with increased hospitalization and mortality among the elderly. Transplant patients have significant risk of acquiring persistent norovirus gastroenteritis. Control and prevention strategies are limited to the use of disinfectants and hand sanitizers, whose efficacy is frequently insufficient. Hence, there is an ample need for antiviral treatment and prophylaxis of norovirus infections. The fact that only a handful of inhibitors of norovirus replication have been reported can largely be attributable to the hampering inability to cultivate human noroviruses in cell culture. The Norwalk replicon-bearing cells and the murine norovirus-infected cell lines are the available models to assess in vitro antiviral activity of compounds. Human noroviruses have been shown to replicate (to some extent) in mice, calves, gnotobiotic pigs, and chimpanzees. Infection of interferon-deficient mice with the murine norovirus results in virus-induced diarrhea. Here we review recent developments in understanding which norovirus proteins or host cell factors may serve as targets for inhibition of viral replication. Given the recent advances, significant progress in the search for antiviral strategies against norovirus infections is expected in the upcoming years. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Structural Basis for Norovirus Inhibition and Fucose Mimicry by Citrate

    SciTech Connect

    Hansman, Grant S.; Shahzad-ul-Hussan, Syed; McLellan, Jason S.; Chuang, Gwo-Yu; Georgiev, Ivelin; Shimoike, Takashi; Katayama, Kazuhiko; Bewley, Carole A.; Kwong, Peter D.

    2012-01-20

    Human noroviruses bind with their capsid-protruding domains to histo-blood-group antigens (HBGAs), an interaction thought to direct their entry into cells. Although human noroviruses are the major cause of gastroenteritis outbreaks, development of antivirals has been lacking, mainly because human noroviruses cannot be cultivated. Here we use X-ray crystallography and saturation transfer difference nuclear magnetic resonance (STD NMR) to analyze the interaction of citrate with genogroup II (GII) noroviruses. Crystals of citrate in complex with the protruding domain from norovirus GII.10 Vietnam026 diffracted to 1.4 {angstrom} and showed a single citrate bound at the site of HBGA interaction. The citrate interaction was coordinated with a set of capsid interactions almost identical to that involved in recognizing the terminal HBGA fucose, the saccharide which forms the primary conserved interaction between HBGAs and GII noroviruses. Citrate and a water molecule formed a ring-like structure that mimicked the pyranoside ring of fucose. STD NMR showed the protruding domain to have weak affinity for citrate (460 {mu}M). This affinity, however, was similar to the affinities of the protruding domain for fucose (460 {mu}M) and H type 2 trisaccharide (390 {mu}M), an HBGA shown previously to be specifically recognized by human noroviruses. Importantly, competition STD NMR showed that citrate could compete with HBGA for norovirus binding. Together, the results suggest that citrate and other glycomimetics have the potential to block human noroviruses from binding to HBGAs.

  8. Structural basis for norovirus inhibition and fucose mimicry by citrate.

    PubMed

    Hansman, Grant S; Shahzad-Ul-Hussan, Syed; McLellan, Jason S; Chuang, Gwo-Yu; Georgiev, Ivelin; Shimoike, Takashi; Katayama, Kazuhiko; Bewley, Carole A; Kwong, Peter D

    2012-01-01

    Human noroviruses bind with their capsid-protruding domains to histo-blood-group antigens (HBGAs), an interaction thought to direct their entry into cells. Although human noroviruses are the major cause of gastroenteritis outbreaks, development of antivirals has been lacking, mainly because human noroviruses cannot be cultivated. Here we use X-ray crystallography and saturation transfer difference nuclear magnetic resonance (STD NMR) to analyze the interaction of citrate with genogroup II (GII) noroviruses. Crystals of citrate in complex with the protruding domain from norovirus GII.10 Vietnam026 diffracted to 1.4 Å and showed a single citrate bound at the site of HBGA interaction. The citrate interaction was coordinated with a set of capsid interactions almost identical to that involved in recognizing the terminal HBGA fucose, the saccharide which forms the primary conserved interaction between HBGAs and GII noroviruses. Citrate and a water molecule formed a ring-like structure that mimicked the pyranoside ring of fucose. STD NMR showed the protruding domain to have weak affinity for citrate (460 μM). This affinity, however, was similar to the affinities of the protruding domain for fucose (460 μM) and H type 2 trisaccharide (390 μM), an HBGA shown previously to be specifically recognized by human noroviruses. Importantly, competition STD NMR showed that citrate could compete with HBGA for norovirus binding. Together, the results suggest that citrate and other glycomimetics have the potential to block human noroviruses from binding to HBGAs.

  9. Adsorption and Aggregation Properties of Norovirus GI and GII Virus-like Particles Demonstrate Differing Responses to Solution Chemistry

    PubMed Central

    DA SILVA, ALLEGRA K.; KAVANAGH, OWEN V.; ESTES, MARY K.; ELIMELECH, MENACHEM

    2014-01-01

    The transport properties (adsorption and aggregation behavior) of virus-like particles (VLPs) of two strains of norovirus (“Norwalk” GI.1 and “Houston” GII.4) were studied in a variety of solution chemistries. GI.1 and GII.4 VLPs were found to be stable against aggregation at pH 4.0–8.0. At pH 9.0, GI.1 VLPs rapidly disintegrated. The attachment efficiencies (α) of GI.1 and GII.4 VLPs to silica increased with increasing ionic strength in NaCl solutions at pH 8.0. The attachment efficiency of GI.1 VLPs decreased as pH was increased above the isoelectric point (pH 5.0), whereas at and below the isoelectric point, the attachment efficiency was erratic. Ca2+ and Mg2+ dramatically increased the attachment efficiencies of GI.1 and GII.4 VLPs, which may be due to specific interactions with the VLP capsids. Bicarbonate decreased attachment efficiencies for both GI.1 and GII.4 VLPs, whereas phosphate decreased the attachment efficiency of GI.1, while increasing GII.4 attachment efficiency. The observed differences in GI.1 and GII.4 VLP attachment efficiencies in response to solution chemistry may be attributed to differential responses of the unique arrangement of exposed amino acid residues on the capsid surface of each VLP strain. PMID:21121659

  10. Advances in Laboratory Methods for Detection and Typing of Norovirus

    PubMed Central

    2014-01-01

    Human noroviruses are the leading cause of epidemic and sporadic gastroenteritis across all age groups. Although the disease is usually self-limiting, in the United States norovirus gastroenteritis causes an estimated 56,000 to 71,000 hospitalizations and 570 to 800 deaths each year. This minireview describes the latest data on laboratory methods (molecular, immunological) for norovirus detection, including real-time reverse transcription-quantitative PCR (RT-qPCR) and commercially available immunological assays as well as the latest FDA-cleared multi-gastrointestinal-pathogen platforms. In addition, an overview is provided on the latest nomenclature and molecular epidemiology of human noroviruses. PMID:24989606

  11. Inactivation of a human norovirus surrogate by high-pressure processing: effectiveness, mechanism, and potential application in the fresh produce industry.

    PubMed

    Lou, Fangfei; Neetoo, Hudaa; Chen, Haiqiang; Li, Jianrong

    2011-03-01

    Fresh produce is often a high-risk food for norovirus contamination because it can become contaminated at both preharvest and postharvest stages and it undergoes minimal or no processing. Currently, there is no effective method to eliminate the viruses from fresh produce. This study systematically investigated the effectiveness of high-pressure processing (HPP) on inactivating murine norovirus (MNV-1), a surrogate for human norovirus, in aqueous medium and fresh produce. We demonstrated that MNV-1 was effectively inactivated by HPP. More than a 5-log-PFU/g reduction was achieved in all tested fresh produce when it was pressurized at 400 MPa for 2 min at 4°C. We found that pressure, pH, temperature, and food matrix affected the virus survival in foods. MNV-1 was more effectively inactivated at 4°C than at 20°C in both medium and fresh produce. MNV-1 was also more sensitive to HPP at neutral pH than at acidic pH. We further demonstrated that disruption of viral capsid structure, but not degradation of viral genomic RNA, is the primary mechanism of virus inactivation by HPP. However, HPP does not degrade viral capsid protein, and the pressurized capsid protein was still antigenic. Overall, HPP had a variable effect on the sensorial quality of fresh produce, depending on the pressure level and type of product. Taken together, HPP effectively inactivated a human norovirus surrogate in fresh produce with a minimal impact on food quality and thus can provide a novel intervention for processing fruits intended for frozen storage and related products such as purees, sauces, and juices.

  12. Therapeutics and Immunoprophylaxis against Noroviruses and Rotaviruses.

    PubMed

    Ghosh, Souvik; Malik, Yashpal Singh; Kobayashi, Nobumichi

    2017-09-12

    Noroviruses and rotaviruses are important viral etiologies of severe gastroenteritis. Noroviruses are the primary cause of non-bacterial diarrheal outbreaks in humans, whilst rotaviruses are a major cause of childhood diarrhea. Although both enteric pathogens substantially impact human health and economies, there are no approved drugs against noroviruses and rotaviruses, so far. On the other hand, whilst the currently licensed rotavirus vaccines have been successfully implemented in over 100 countries, the most advanced norovirus vaccine has recently completed phase-I and II trials. Technological advances coupled with proper understanding of viral morphology and replication over the past decade has facilitated pioneering research on therapeutics and immunoprophylaxis against noroviruses and rotaviruses, with promising outcomes in human clinical trials of some of the drugs and vaccines. Herein, we focus on the developments in the field of norovirus and rotavirus therapeutics and immunoprophylaxis, such as potential antiviral drug molecules, passive immunotherapies (oral human immunoglobulins, egg yolk and bovine colostral antibodies, llama-derived nanobodies, and antibodies expressed in probiotics, plants, rice grains and insect larvae), immune system modulators, probiotics, phytochemicals and other biological substances such as bovine milk proteins, therapeutic nanoparticles, hydrogels and viscogens, conventional viral vaccines (live and inactivated whole virus vaccines), and genetically engineered viral vaccines (reassortant viral particles, virus-like particles (VLPs) and other subunit recombinant vaccines including multi-valent viral vaccines, edible plant vaccines, and encapsulated viral particles). Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  13. Inactivation of human norovirus and Tulane virus in simple media and fresh whole strawberries by ionizing radiation.

    PubMed

    DiCaprio, Erin; Phantkankum, Nuttapong; Culbertson, Doug; Ma, Yuanmei; Hughes, John H; Kingsley, David; Uribe, Roberto M; Li, Jianrong

    2016-09-02

    Human norovirus (NoV) is a major cause of fresh produce-associated outbreaks and human NoV in irrigation water can potentially lead to viral internalization in fresh produce. Therefore, there is a need to develop novel intervention strategies to target internalized viral pathogens while maintaining fresh produce quality. In this study electron beam (E-beam) and gamma radiation were evaluated for efficacy against a human NoV GII.4 strain and Tulane virus (TV). Virus survival following ionizing radiation treatments was determined using direct quantitative reverse transcriptase PCR (RT-qPCR), the porcine gastric mucin magnetic bead (PGM-MB) binding assay followed by RT-qPCR, and plaque assay. In simple media, a high dose of E-beam treatment was required to completely abolish the receptor binding ability of human NoV (35.3kGy) and TV (19.5-24.1kGy), as assessed using the PGM-MB binding assay. Both human NoV and TV were more susceptible to gamma irradiation than E-beam, requiring 22.4kGy to achieve complete inactivation. In whole strawberries, no human NoV or TV RNA was detected following 28.7kGy of E-beam treatment using the PGM-MB binding assay. Overall, human NoV and TV are highly resistant to ionizing radiation and therefore the technology may not be suitable to eliminate viruses in fresh produce at the currently approved levels. In addition, the PGM-MB binding assay is an improved method to detect viral infectivity compared to direct RT-qPCR. Copyright © 2016. Published by Elsevier B.V.

  14. Binding to histo-blood group antigen-expressing bacteria protects human norovirus from acute heat stress

    PubMed Central

    Li, Dan; Breiman, Adrien; le Pendu, Jacques; Uyttendaele, Mieke

    2015-01-01

    This study aims to investigate if histo-blood group antigen (HBGA) expressing bacteria have any protective role on human norovirus (NoV) from acute heat stress. Eleven bacterial strains were included, belonging to Escherichia coli, Enterobacter cloacae, Enterobacter aerogenes, Clostridium difficile, Bifidobacterium adolescentis, and B. longum. HBGA expression of the bacteria as well as binding of human NoV virus-like particles (VLPs, GI.1, and GII.4 strains) to the bacteria were detected by flow cytometry. NoV VLPs pre-incubated with HBGA expressing or non-HBGA expressing bacteria were heated and detected by both direct ELISA and porcine gastric mucin-binding assay. The NoV-binding abilities of the bacteria correlated well with their HBGA expression profiles. Two HBGA expressing E. coli (LMG8223 and LFMFP861, both GI.1 and GII.4 binders) and one non-HBGA expressing E. coli (ATCC8739, neither GI.1 nor GII.4 binder) were selected for the heat treatment test with NoV VLPs. Compared with the same cell numbers of non-HBGA expressing E. coli, the presence of HBGA-expressing E. coli could always maintain higher antigen integrity, as well as mucin-binding ability of NoV VLPs of both GI.1 and GII.4 after heat-treatment at 90°C for 2 min. These results indicate that HBGA-expressing bacteria may protect NoVs during the food processing treatments, thereby facilitating their transmission. PMID:26191052

  15. Biochemical Evaluation of the Inhibition Properties of Favipiravir and 2′-C-Methyl-Cytidine Triphosphates against Human and Mouse Norovirus RNA Polymerases

    PubMed Central

    Tucker, Kathryn; Lin, Xiaoyan; Kao, C. Cheng; Shaw, Ken; Tan, Hua; Symons, Julian; Behera, Ishani; Rajwanshi, Vivek K.; Dyatkina, Natalia; Wang, Guangyi; Beigelman, Leo

    2015-01-01

    Norovirus (NoV) is a positive-sense single-stranded RNA virus that causes acute gastroenteritis and is responsible for 200,000 deaths per year worldwide. No effective vaccine or treatment is available. Recent studies have shown that the nucleoside analogs favipiravir (T-705) and 2′-C-methyl-cytidine (2CM-C) inhibit NoV replication in vitro and in animal models, but their precise mechanism of action is unknown. We evaluated the molecular interactions between nucleoside triphosphates and NoV RNA-dependent RNA polymerase (NoVpol), the enzyme responsible for replication and transcription of NoV genomic RNA. We found that T-705 ribonucleoside triphosphate (RTP) and 2CM-C triphosphate (2CM-CTP) equally inhibited human and mouse NoVpol activities at concentrations resulting in 50% of maximum inhibition (IC50s) in the low micromolar range. 2CM-CTP inhibited the viral polymerases by competing directly with natural CTP during primer elongation, whereas T-705 RTP competed mostly with ATP and GTP at the initiation and elongation steps. Incorporation of 2CM-CTP into viral RNA blocked subsequent RNA synthesis, whereas T-705 RTP did not cause immediate chain termination of NoVpol. 2CM-CTP and T-705 RTP displayed low levels of enzyme selectivity, as they were both recognized as substrates by human mitochondrial RNA polymerase. The level of discrimination by the human enzyme was increased with a novel analog of T-705 RTP containing a 2′-C-methyl substitution. Collectively, our data suggest that 2CM-C inhibits replication of NoV by acting as a classic chain terminator, while T-705 may inhibit the virus by multiple mechanisms of action. Understanding the precise mechanism of action of anti-NoV compounds could provide a rational basis for optimizing their inhibition potencies and selectivities. PMID:26392512

  16. The P4-P2′ Amino Acids Surrounding Human Norovirus Polyprotein Cleavage Sites Define the Core Sequence Regulating Self-Processing Order

    PubMed Central

    May, Jared; Viswanathan, Prasanth; Ng, Kenneth K.-S.; Medvedev, Alexei

    2014-01-01

    ABSTRACT Noroviruses (NoV) are members of the family Caliciviridae. The human NoV open reading frame 1 (ORF1) encodes a 200-kDa polyprotein which is cleaved by the viral 20-kDa 3C-like protease (Pro, NS6) into 6 nonstructural proteins that are necessary for viral replication. The NoV ORF1 polyprotein is processed in a specific order, with “early” sites (NS1/2-3 and NS3-4) being cleaved rapidly and three “late” sites (NS4-5, NS5-6, and NS6-7) processed subsequently and less efficiently. Previously, we demonstrated that the NoV polyprotein processing order is directly correlated with the efficiency of the enzyme, which is regulated by the primary amino acid sequences surrounding ORF1 cleavage sites. Using fluorescence resonance energy transfer (FRET) peptides representing the NS2-3 and NS6-7 ORF1 cleavage sites, we now demonstrate that the amino acids spanning positions P4 to P2′ (P4-P2′) surrounding each site comprise the core sequence controlling NoV protease enzyme efficiency. Furthermore, the NoV polyprotein self-processing order can be altered by interchanging this core sequence between NS2-3 and any of the three late sites in in vitro transcription-translation assays. We also demonstrate that the nature of the side chain at the P3 position for the NS1/2-3 (Nterm/NTPase) site confers significant influence on enzyme catalysis (kcat and kcat/Km), a feature overlooked in previous structural studies. Molecular modeling provides possible explanations for the P3 interactions with NoV protease. IMPORTANCE Noroviruses (NoV) are the prevailing cause of nonbacterial acute gastroenteritis worldwide and pose a significant financial burden on health care systems. Proteolytic processing of the viral nonstructural polyprotein is required for norovirus replication. Previously, the core sequence of amino acids surrounding the scissile bonds responsible for governing the relative processing order had not been determined. Using both FRET-based peptides and full

  17. Frequent Use of the IgA Isotype in Human B Cells Encoding Potent Norovirus-Specific Monoclonal Antibodies That Block HBGA Binding

    PubMed Central

    Shanker, Sreejesh; Prasad, B. V. Venkataram; Atmar, Robert L.; Estes, Mary K.; Crowe, James E.

    2016-01-01

    Noroviruses (NoV) are the most common cause of non-bacterial acute gastroenteritis and cause local outbreaks of illness, especially in confined situations. Despite being identified four decades ago, the correlates of protection against norovirus gastroenteritis are still being elucidated. Recent studies have shown an association of protection with NoV-specific serum histo-blood group antigen-blocking antibody and with serum IgA in patients vaccinated with NoV VLPs. Here, we describe the isolation and characterization of human monoclonal IgG and IgA antibodies against a GI.I NoV, Norwalk virus (NV). A higher proportion of the IgA antibodies blocked NV VLP binding to glycans than did IgG antibodies. We generated isotype-switched variants of IgG and IgA antibodies to study the effects of the constant domain on blocking and binding activities. The IgA form of antibodies appears to be more potent than the IgG form in blocking norovirus binding to histo-blood group antigens. These studies suggest a unique role for IgA antibodies in protection from NoV infections by blocking attachment to cell receptors. PMID:27355511

  18. Norovirus infection in primary immune deficiency.

    PubMed

    Brown, Li-An K; Clark, Ian; Brown, Julianne R; Breuer, Judith; Lowe, David M

    2017-03-08

    Norovirus is acknowledged to be a leading cause of acute gastroenteritis worldwide, and its importance as a cause of chronic infection in immune deficient hosts is increasingly recognised. Current evidence suggests that a coordinated response of innate immune mechanisms, CD8+ cytotoxicity and a humoral response, with CD4+ orchestration, is necessary for norovirus clearance. We explain how primary immune deficiency impairs these host defences and predisposes to chronic infection, associated with protracted diarrhoea, weight loss, and requirement for parenteral nutrition. The mucosal villous atrophy frequently seen in norovirus infection appears to be immune mediated, suggesting that some functional immune response is required in order for chronic norovirus infection to become symptomatic in primary immune deficiency. We provide a comprehensive summary of published cases of norovirus infection in patients with primary immune deficiency. Spontaneous viral clearance has been described; however, the majority of reported cases have had prolonged and severe illness. Treatment strategies are discussed in detail. Approaches that have been tried in patients with primary immune deficiency include exclusion diets, enteral and intravenous immunoglobulins, breast milk, immunosuppressants, ribavirin, and nitazoxanide. To date, only ribavirin has been used with apparent success to achieve clearance of chronic norovirus in primary immune deficiency, and randomised controlled trials are needed to evaluate a number of promising therapies that are discussed.

  19. Increased and prolonged human norovirus infection in RAG2/IL2RG deficient gnotobiotic pigs with severe combined immunodeficiency

    PubMed Central

    Lei, Shaohua; Ryu, Junghyun; Wen, Ke; Twitchell, Erica; Bui, Tammy; Ramesh, Ashwin; Weiss, Mariah; Li, Guohua; Samuel, Helen; Clark-Deener, Sherrie; Jiang, Xi; Lee, Kiho; Yuan, Lijuan

    2016-01-01

    Application of genetically engineered (GE) large animals carrying multi-allelic modifications has been hampered by low efficiency in production and extended gestation period compared to rodents. Here, we rapidly generated RAG2/IL2RG double knockout pigs using direct injection of CRISPR/Cas9 system into developing embryos. RAG2/IL2RG deficient pigs were immunodeficient, characterized by depletion of lymphocytes and either absence of or structurally abnormal immune organs. Pigs were maintained in gnotobiotic facility and evaluated for human norovirus (HuNoV) infection. HuNoV shedding lasted for 16 days in wild type pigs, compared to 27 days (until the end of trials) in RAG2/IL2RG deficient pigs. Additionally, higher HuNoV titers were detected in intestinal tissues and contents and in blood, indicating increased and prolonged HuNoV infection in RAG2/IL2RG deficient pigs and the importance of lymphocytes in HuNoV clearance. These results suggest that GE immunodeficient gnotobiotic pigs serve as a novel model for biomedical research and will facilitate HuNoV studies. PMID:27118081

  20. Relevance of secretor status genotype and microbiota composition in susceptibility to rotavirus and norovirus infections in humans.

    PubMed

    Rodríguez-Díaz, Jesús; García-Mantrana, Izaskun; Vila-Vicent, Susana; Gozalbo-Rovira, Roberto; Buesa, Javier; Monedero, Vicente; Collado, Maria Carmen

    2017-03-30

    Host genetic factors, such as histo-blood group antigens (HBGAs), are associated with susceptibility to norovirus (NoV) and rotavirus (RV) infections. Recent advances point to the gut microbiome as a key player necessary for a viral pathogen to cause infection. In vitro NoV attachment to host cells and resulting infections have been linked to interactions with certain bacterial types in the gut microbiota. We investigated the relationship between host genotype, gut microbiota, and viral infections. Saliva and fecal samples from 35 adult volunteers were analysed for secretor status genotype, the gut microbiota composition by 16S rRNA gene sequencing, and salivary IgA titers to NoV and RV. Higher levels of IgA against NoV and RV were related to secretor-positive status. No significant differences were found between the FUT2 genotype groups, although the multivariate analysis showed a significant impact of host genotype on specific viral susceptibilities in the microbiome composition. A specific link was found between the abundance of certain bacterial groups, such as Faecalibacterium and Ruminococcus spp., and lower IgA titers against NoV and RV. As a conclusion, we can state that there is a link between host genetics, gut microbiota, and susceptibility to viral infections in humans.

  1. Relevance of secretor status genotype and microbiota composition in susceptibility to rotavirus and norovirus infections in humans

    PubMed Central

    Rodríguez-Díaz, Jesús; García-Mantrana, Izaskun; Vila-Vicent, Susana; Gozalbo-Rovira, Roberto; Buesa, Javier; Monedero, Vicente; Collado, Maria Carmen

    2017-01-01

    Host genetic factors, such as histo-blood group antigens (HBGAs), are associated with susceptibility to norovirus (NoV) and rotavirus (RV) infections. Recent advances point to the gut microbiome as a key player necessary for a viral pathogen to cause infection. In vitro NoV attachment to host cells and resulting infections have been linked to interactions with certain bacterial types in the gut microbiota. We investigated the relationship between host genotype, gut microbiota, and viral infections. Saliva and fecal samples from 35 adult volunteers were analysed for secretor status genotype, the gut microbiota composition by 16S rRNA gene sequencing, and salivary IgA titers to NoV and RV. Higher levels of IgA against NoV and RV were related to secretor-positive status. No significant differences were found between the FUT2 genotype groups, although the multivariate analysis showed a significant impact of host genotype on specific viral susceptibilities in the microbiome composition. A specific link was found between the abundance of certain bacterial groups, such as Faecalibacterium and Ruminococcus spp., and lower IgA titers against NoV and RV. As a conclusion, we can state that there is a link between host genetics, gut microbiota, and susceptibility to viral infections in humans. PMID:28358023

  2. Preventing and controlling human noroviruses in South Carolina long-term care facilities: An analysis of institutional policies and procedures.

    PubMed

    Jayasekara, Lalani; Leone, Cortney M; Sharp, Julia; Fraser, Angela

    2016-01-01

    Long-term care (LTC) facilities are the number one setting for human norovirus (HuNoV) outbreaks in the United States (60%). We aimed to determine alignment of policies and procedures in LTC facilities in South Carolina with Centers for Disease Control and Prevention (CDC) recommendations and to determine readability based on Federal Plain Language Guidelines and Microsoft Word readability statistics. Most facilities (n = 21) had procedures for hand hygiene, but recommendations for handwashing events and duration varied greatly. Less than half (n = 11) had separate procedures devoted to HuNoV outbreak control. Fifteen required disinfection of bodily fluids. Seven had procedures for exclusion of sick staff during an outbreak. Both hand hygiene and bodily fluid cleanup procedures had low mean scores for readability. Mean Flesch Reading Ease and Flesch-Kincaid Grade Level for both procedures were in the range of difficult to understand. Most LTC policies and procedures were not consistent with CDC recommendations for HuNoV. Moreover, readability of all procedures is needed so LTC workers can easily understand and implement prevention and control procedures. Published by Elsevier Inc.

  3. Genetic diversity and distribution of human norovirus in China (1999-2011).

    PubMed

    Yu, Yongxin; Yan, Shuling; Li, Bailin; Pan, Yingjie; Wang, Yongjie

    2014-01-01

    Noroviruses (NoVs) are a leading cause of epidemic and sporadic acute gastroenteritis worldwide. However, the genetic diversity and geographical distribution of NoV isolates from China have not been well described thus far. In this study, all NoV sequences obtained in China from 1999 to 2011 (n = 983), both partial and complete genomes, were downloaded from GenBank. Genotyping and phylogenetic and recombination analyses were performed in order to gain a better understanding of the distribution and genetic diversity of NoVs in China. The results indicated that approximately 90% of NoV sequences were obtained from the coastal regions of China, and most of the NoV sequences from distinct geographical regions appeared to be closely related. GII.4 was the most prevalent genotype, accounting for 64.4% of all genotypes, followed by GII.12 (13.9%) and GII.3 (7.0%). Over the last decade, the GII.4 variants were dominated by successive circulation of GII.4/2002, GII.4/2004, GII.4/2006b, and GII.4/2008, with GII.4/2006b continuing to date. A relatively high frequency of NoV intergenotype recombinants was identified. The most common ORF1/ORF2 intergenotype recombinant was GII.12/GII.4 (n = 11), and the relative frequency was up to 30% among all the recombinant strains (n = 36). These findings may aid in the evaluation and implementation of appropriate measures for monitoring NoV infectious diseases in China.

  4. Survival and transfer of murine norovirus 1, a surrogate for human noroviruses, during the production process of deep-frozen onions and spinach.

    PubMed

    Baert, Leen; Uyttendaele, Mieke; Vermeersch, Mattias; Van Coillie, Els; Debevere, Johan

    2008-08-01

    The reduction of murine norovirus 1 (MNV-1) on onions and spinach by washing was investigated as was the risk of contamination during the washing procedure. To decontaminate wash water, the industrial sanitizer peracetic acid (PAA) was added to the water, and the survival of MNV-1 was determined. In contrast to onions, spinach undergoes a heat treatment before freezing. Therefore, the resistance of MNV-1 to blanching of spinach was examined. MNV-1 genomic copies were detected with a real-time reverse transcription PCR assay in PAA-treated water and blanched spinach, and PFUs (representing infectious MNV-1 units) were determined with a plaque assay. A < or = 1-log reduction in MNV-1 PFUs was achieved by washing onion bulbs and spinach leaves. More than 3 log PFU of MNV-1 was transmitted to onion bulbs and spinach leaves when these vegetables were washed in water containing approximately 5 log PFU/ml. No decline of MNV-1 occurred in used industrial spinach wash water after 6 days at room temperature. A concentration of 20 ppm of PAA in demineralized water (pH 4.13) and in potable water (pH 7.70) resulted in reductions of 2.88 +/- 0.25 and 2.41 +/- 0.18 log PFU, respectively, after 5 min of exposure, but no decrease in number of genomic copies was observed. No reduction of MNV-1 PFUs was observed on frozen onions or spinach during storage for 6 months. Blanching spinach (80 degrees C for 1 min) resulted in at least 2.44-log reductions of infectious MNV-1, but many genomic copies were still present.

  5. Immunomagnetic separation combined with RT-qPCR for determining the efficacy of disinfectants against human noroviruses.

    PubMed

    Liu, Pengbo; Kim, Myung; Schlesinger, David; Kranz, Christine; Ha, Sangdo; Ha, Jeehyoung; Slauch, James; Baek, Seungbum; Moe, Christine

    2015-01-01

    Little is known about the effectiveness of disinfectants against human noroviruses (NoV) partially because human NoV cannot be routinely cultured in laboratory. The objective of this study was to develop a NoV monoclonal antibody-conjugated immunomagnetic separation (IMS) procedure combined with real-time reverse transcription polymerase chain reaction (RT-qPCR) assays to study the in vitro efficacy of disinfectants against human NoV. Monoclonal antibodies against Norwalk virus (NV, GI.1) and NoV GII.4 were produced using unique NoV capsid proteins, and the antibodies were conjugated to magnetic Dynalbeads. The immunomagnetic beads were used to simultaneously capture intact NoV in samples and effectively remove PCR inhibitors. We examined the efficacy of ethanol, sodium hypochlorite, nine commercially available disinfectants, and one prototype disinfectant using the IMS/RT-qPCR. The sensitivity of this procedure was approximately 100 virus particles for both the NV and GII.4 viruses. The average log reductions in in vitro activities varied between disinfectants. The prototype disinfectant produced an average 3.19-log reduction in NV and a 1.38-log reduction in GII.4. The prototype disinfectant is promising of inactivating NoV. This method can be used to evaluate in vitro activity of disinfectants against human NoV. The IMS/RT-qPCR method is promising as an effective method to remove PCR inhibitors in disinfectants and enable the evaluation of the efficacy of disinfectants. Copyright © 2014 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  6. Median infectious dose of human norovirus GII.4 in gnotobiotic pigs is decreased by simvastatin treatment and increased by age

    PubMed Central

    Bui, Tammy; Kocher, Jacob; Li, Yanru; Wen, Ke; Li, Guohua; Liu, Fangning; Yang, Xingdong; LeRoith, Tanya; Tan, Ming; Xia, Ming; Zhong, Weiming; Jiang, Xi

    2013-01-01

    Human noroviruses (NoVs), a major cause of viral gastroenteritis, are difficult to study due to the lack of a cell-culture and a small-animal model. Pigs share with humans the types A and H histo-blood group antigens on the intestinal epithelium and have been suggested as a potential model for studies of NoV pathogenesis, immunity and vaccines. In this study, the effects of age and a cholesterol-lowering drug, simvastatin, on the susceptibility of pigs to NoV infection were evaluated. The median infectious dose (ID50) of a genogroup II, genotype 4 (GII.4) 2006b variant was determined. The ID50 in neonatal (4–5 days of age) pigs was ≤2.74×103 viral RNA copies. In older pigs (33–34 days of age), the ID50 was 6.43×104 but decreased to <2.74×103 in simvastatin-fed older pigs. Evidence of NoV infection was obtained by increased virus load in the intestinal contents, cytopathological changes in the small intestine, including irregular microvilli, necrosis and apoptosis, and detection of viral antigen in the tip of villi in duodenum. This GII.4 variant was isolated in 2008 from a patient from whom a large volume of stool was collected. GII.4 NoVs are continuously subjected to selective pressure by human immunity, and antigenically different GII.4 NoV variants emerge every 1–2 years. The determination of the ID50 of this challenge virus is valuable for evaluation of protection against different GII.4 variants conferred by NoV vaccines in concurrence with other GII.4 variants in the gnotobiotic pig model. PMID:23804568

  7. Ultrasensitive Norovirus Detection Using DNA Aptasensor Technology

    PubMed Central

    Giamberardino, Amanda; Labib, Mahmoud; Hassan, Eman M.; Tetro, Jason A.; Springthorpe, Susan; Sattar, Syed A.; Berezovski, Maxim V.; DeRosa, Maria C.

    2013-01-01

    DNA aptamers were developed against murine norovirus (MNV) using SELEX (Systematic Evolution of Ligands by EXponential enrichment). Nine rounds of SELEX led to the discovery of AG3, a promising aptamer with very high affinity for MNV as well as for lab-synthesized capsids of a common human norovirus (HuNoV) outbreak strain (GII.3). Using fluorescence anisotropy, AG3 was found to bind with MNV with affinity in the low picomolar range. The aptamer could cross-react with HuNoV though it was selected against MNV. As compared to a non-specific DNA control sequence, the norovirus-binding affinity of AG3 was about a million-fold higher. In further tests, the aptamer also showed nearly a million-fold higher affinity for the noroviruses than for the feline calicivirus (FCV), a virus similar in size and structure to noroviruses. AG3 was incorporated into a simple electrochemical sensor using a gold nanoparticle-modified screen-printed carbon electrode (GNPs-SPCE). The aptasensor could detect MNV with a limit of detection of approximately 180 virus particles, for possible on-site applications. The lead aptamer candidate and the aptasensor platform show promise for the rapid detection and identification of noroviruses in environmental and clinical samples. PMID:24244426

  8. Bacterial Surface-Displayed GII.4 Human Norovirus Capsid Proteins Bound to HBGA-Like Molecules in Romaine Lettuce.

    PubMed

    Wang, Ming; Rong, Shaofeng; Tian, Peng; Zhou, Yue; Guan, Shimin; Li, Qianqian; Wang, Dapeng

    2017-01-01

    Human Noroviruses (HuNoVs) are the main cause of non-bacterial gastroenteritis. Contaminated produce is a main vehicle for dissemination of HuNoVs. In this study, we used an ice nucleation protein mediated surface display system to present the protruding domain of GII.4 HuNoV capsid protein on bacterial surface and used it as a new strategy to explore interaction between HuNoV protein and receptor candidates from romaine lettuce. The surface-displayed HuNoV proteins were confirmed on the surface of the transformed bacteria by an immunofluorescence assay. The distribution patterns of the surface-displayed HuNoV proteins in romaine lettuce were identified through a confocal immunofluorescence assay. The surface-displayed HuNoV proteins could be found in the stomata, and the surfaces of vein and leaf of romaine lettuce. The surface-displayed HuNoV proteins could be captured by an ELISA assay utilizing extract from leaf (LE) or vein (VE). The binding of the surface-displayed HuNoV proteins to LE or VE could be competitively blocked by histo-blood group antigens from human saliva. In addition, the binding of the surface-displayed HuNoV proteins to LE or VE could also be attenuated by heat denaturation of lettuce proteins, and abolished by oxidation of lettuce carbohydrates. The results indicated that histo-blood group antigen-like molecules in LE or VE were involved in the binding of the surface-displayed HuNoV proteins to romaine lettuce. All data demonstrated that the surface-displayed HuNoV proteins could be utilized in a new and simple system for investigation of the interaction between the HuNoVs and their candidate ligands.

  9. Randomized, double-blinded clinical trial for human norovirus inactivation in oysters by high hydrostatic pressure processing.

    PubMed

    Leon, Juan S; Kingsley, David H; Montes, Julia S; Richards, Gary P; Lyon, G Marshall; Abdulhafid, Gwen M; Seitz, Scot R; Fernandez, Marina L; Teunis, Peter F; Flick, George J; Moe, Christine L

    2011-08-01

    Contamination of oysters with human noroviruses (HuNoV) constitutes a human health risk and may lead to severe economic losses in the shellfish industry. There is a need to identify a technology that can inactivate HuNoV in oysters. In this study, we conducted a randomized, double-blinded clinical trial to assess the effect of high hydrostatic pressure processing (HPP) on Norwalk virus (HuNoV genogroup I.1) inactivation in virus-seeded oysters ingested by subjects. Forty-four healthy, positive-secretor adults were divided into three study phases. Subjects in each phase were randomized into control and intervention groups. Subjects received Norwalk virus (8FIIb, 1.0 × 10(4) genomic equivalent copies) in artificially seeded oysters with or without HPP treatment (400 MPa at 25°C, 600 MPa at 6°C, or 400 MPa at 6°C for 5 min). HPP at 600 MPa, but not 400 MPa (at 6° or 25°C), completely inactivated HuNoV in seeded oysters and resulted in no HuNoV infection among these subjects, as determined by reverse transcription-PCR detection of HuNoV RNA in subjects' stool or vomitus samples. Interestingly, a white blood cell (granulocyte) shift was identified in 92% of the infected subjects and was significantly associated with infection (P = 0.0014). In summary, these data suggest that HPP is effective at inactivating HuNoV in contaminated whole oysters and suggest a potential intervention to inactivate infectious HuNoV in oysters for the commercial shellfish industry.

  10. Bacterial Surface-Displayed GII.4 Human Norovirus Capsid Proteins Bound to HBGA-Like Molecules in Romaine Lettuce

    PubMed Central

    Wang, Ming; Rong, Shaofeng; Tian, Peng; Zhou, Yue; Guan, Shimin; Li, Qianqian; Wang, Dapeng

    2017-01-01

    Human Noroviruses (HuNoVs) are the main cause of non-bacterial gastroenteritis. Contaminated produce is a main vehicle for dissemination of HuNoVs. In this study, we used an ice nucleation protein mediated surface display system to present the protruding domain of GII.4 HuNoV capsid protein on bacterial surface and used it as a new strategy to explore interaction between HuNoV protein and receptor candidates from romaine lettuce. The surface-displayed HuNoV proteins were confirmed on the surface of the transformed bacteria by an immunofluorescence assay. The distribution patterns of the surface-displayed HuNoV proteins in romaine lettuce were identified through a confocal immunofluorescence assay. The surface-displayed HuNoV proteins could be found in the stomata, and the surfaces of vein and leaf of romaine lettuce. The surface-displayed HuNoV proteins could be captured by an ELISA assay utilizing extract from leaf (LE) or vein (VE). The binding of the surface-displayed HuNoV proteins to LE or VE could be competitively blocked by histo-blood group antigens from human saliva. In addition, the binding of the surface-displayed HuNoV proteins to LE or VE could also be attenuated by heat denaturation of lettuce proteins, and abolished by oxidation of lettuce carbohydrates. The results indicated that histo-blood group antigen-like molecules in LE or VE were involved in the binding of the surface-displayed HuNoV proteins to romaine lettuce. All data demonstrated that the surface-displayed HuNoV proteins could be utilized in a new and simple system for investigation of the interaction between the HuNoVs and their candidate ligands. PMID:28265267

  11. Binding of Human GII.4 Norovirus Virus-Like Particles to Carbohydrates of Romaine Lettuce Leaf Cell Wall Materials

    PubMed Central

    Esseili, Malak A.

    2012-01-01

    Norovirus (NoV) genogroup II genotype 4 (GII.4) strains are the dominant cause of the majority of food-borne outbreaks, including those that involve leafy greens, such as lettuce. Since human NoVs use carbohydrates of histo-blood group antigens as receptors/coreceptors, we examined the role of carbohydrates in the attachment of NoV to lettuce leaves by using virus-like particles (VLPs) of a human NoV/GII.4 strain. Immunofluorescence analysis showed that the VLPs attached to the leaf surface, especially to cut edges, stomata, and along minor veins. Binding was quantified using enzyme-linked immunosorbent assay (ELISA) performed on cell wall materials (CWM) from innermost younger leaves and outermost lamina of older leaves. The binding to CWM of older leaves was significantly (P < 0.05) higher (1.5- to 2-fold) than that to CWM of younger leaves. Disrupting the carbohydrates of CWM or porcine gastric mucin (PGM) (a carbohydrate control) using 100 mM sodium periodate (NaIO4) significantly decreased the binding an average of 17% in younger leaves, 43% in older leaves, and 92% for PGM. In addition, lectins recognizing GalNAc, GlcNAc, and sialic acid at 100 μg/ml significantly decreased the binding an average of 41%, 33%, and 20% on CWM of older leaves but had no effect on younger leaves. Lectins recognizing α-d-Gal, α-d-Man/α-d-Glc, and α-l-Fuc showed significant inhibition on CWM of older leaves as well as that of younger leaves. All lectins, except for the lectin recognizing α-d-Gal, significantly inhibited NoV VLP binding to PGM. Collectively, our results indicate that NoV VLPs bind to lettuce CWM by utilizing multiple carbohydrate moieties. This binding may enhance virus persistence on the leaf surface and prevent effective decontamination. PMID:22138991

  12. 21 CFR 866.3395 - Norovirus serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Norovirus serological reagents. 866.3395 Section 866.3395 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3395 Norovirus...

  13. 21 CFR 866.3395 - Norovirus serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Norovirus serological reagents. 866.3395 Section 866.3395 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3395 Norovirus...

  14. 21 CFR 866.3395 - Norovirus serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Norovirus serological reagents. 866.3395 Section 866.3395 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3395 Norovirus...

  15. Norovirus GII.17 Natural Infections in Rhesus Monkeys, China

    PubMed Central

    He, Zhanlong; Liu, Bo; Tao, Yufen; Li, Chao; Xia, Ming; Zhong, Weiming; Jiang, Xi

    2017-01-01

    Noroviruses are a leading viral cause of acute gastroenteritis among humans. During the 2014–15 epidemic season, norovirus GII.17 was detected in rhesus monkeys in China. Genetic, structural, and challenge studies revealed virus mutations and verified the infections. Thus, cross-species transmission may occur, and monkeys may be a virus reservoir. PMID:28102802

  16. Norovirus Infection in Harbor Porpoises

    PubMed Central

    Bodewes, Rogier; van Elk, Cornelis E.; van de Bildt, Marco; Getu, Sarah; Aron, Georgina I.; Verjans, Georges M.G.M.; Osterhaus, Albert D.M.E.; van den Brand, Judith M.A.; Kuiken, Thijs; Koopmans, Marion P.G.

    2017-01-01

    A norovirus was detected in harbor porpoises, a previously unknown host for norovirus. This norovirus had low similarity to any known norovirus. Viral RNA was detected primarily in intestinal tissue, and specific serum antibodies were detected in 8 (24%) of 34 harbor porpoises from the North Sea. PMID:27983498

  17. Blood Group Substances as Potential Therapeutic Agents for the Prevention and Treatment of Infection with Noroviruses Proving Novel Binding Patterns in Human Tissues

    PubMed Central

    Yazawa, Shin; Yokobori, Takehiko; Ueta, Gen; Ide, Munenori; Altan, Bolag; Thongprachum, Aksara; Nishimura, Toyo; Nakajima, Tamiko; Kominato, Yoshihiko; Asao, Takayuki; Saniabadi, Abby R.; Furukawa, Kiyoshi; Kuwano, Hiroyuki; Le Pendu, Jacques; Ushijima, Hiroshi

    2014-01-01

    Blood group-related glycans determining ABO and Lewis blood groups are known to function as attachment factors for most of the norovirus (NoV) strains. To identify binding specificity of each NoV, recombinant norovirus-like particles (VLPs) and human saliva samples with different ABO, Lewis phenotypes and secretor status have been commonly applied. When binding specificities of VLPs prepared from 16 different genotypes of NoVs in GI and GII genogroups were characterized in samples of human gastric mucosa compared to human saliva based on blood group phenotypes, considerable differences were observed for several strains. Novel binding specificities determined by an ELISA using preparations from human gastric mucosa were also ascertained by immunohistochemical analyses using human jejunal mucosa, widely believed to be susceptible to NoV infection. Further, A, B and O(H) blood group substances prepared from porcine and squid tissues were found to be effective for preventing ABO blood group-specific binding of VLPs to both saliva and mucosa samples. Therefore, these blood group substances might have potential for the prevention and treatment of NoV infection. PMID:24558470

  18. Review: norovirus prevalence in Belgian, Canadian and French fresh produce: a threat to human health?

    PubMed

    Baert, L; Mattison, K; Loisy-Hamon, F; Harlow, J; Martyres, A; Lebeau, B; Stals, A; Van Coillie, E; Herman, L; Uyttendaele, M

    2011-12-15

    Foodborne viruses, especially noroviruses (NoV), are increasingly reported as the cause of foodborne outbreaks. NoV outbreaks have been reported linked to fresh soft red fruits and leafy greens. Belgium, Canada and France were the first countries to provide data about the prevalence of NoV on fresh produce. In total, 867 samples of leafy greens, 180 samples of fresh soft red fruits and 57 samples of other types of fresh produce (tomatoes, cucumber and fruit salads) were analyzed. Firstly, the NoV detection methodology, including virus and RNA extraction, real-time RT-PCR and quality controls were compared among the three countries. In addition, confirmation and genotyping of the NoV strains was attempted for a subset of NoV positive samples using conventional RT-PCR targeting an alternative region followed by sequencing. Analysis of the process control showed that 653, 179 and 18 samples of the leafy greens, soft red fruits and other fresh produce types were valid for analysis based on the recovery of the process control. NoV was detected by real-time RT-PCR in 28.2% (N=641), 33.3% (N=6) and 50% (N=6) of leafy greens tested in Canada, Belgium and France, respectively. Soft red fruits were found positive by real-time RT-PCR in 34.5% (N=29) and 6.7% (N=150) of the samples tested in Belgium and France, respectively. 55.5% (N=18) of the other fresh produce types, analyzed in Belgium, were found NoV positive by real-time RT-PCR. Conventional RT-PCR resulted in an amplicon of the expected size in 19.5% (52/266) of the NoV positive samples where this assay was attempted. Subsequent sequencing was only successful in 34.6% (18/52) of the suspected amplicons obtained by conventional RT-PCR. From this study, using the described methodology, NoV genomes were frequently detected in fresh produce however sequence confirmation was not successful for the majority of the samples tested. Infection or outbreaks were rarely or not known to be related to the NoV positive samples. With

  19. Effects of High-Hydrostatic Pressure on Inactivation of Human Norovirus and Physical and Sensory Characteristics of Oysters.

    PubMed

    Ye, Mu; Lingham, Talaysha; Huang, Yaoxin; Ozbay, Gulnihal; Ji, Lin; Karwe, Mukund; Chen, Haiqiang

    2015-06-01

    The purpose of the study was to determine the effect of high-hydrostatic pressure (HHP) on inactivation of human norovirus (HuNoV) in oysters and to evaluate organoleptic characteristics of oysters treated at pressure levels required for HuNoV inactivation. Genogroup I.1 (GI.1) or Genogroup II.4 (GII.4) HuNoV was inoculated into oysters and treated at 300 to 600 MPa at 25 and 0 °C for 2 min. After HHP, viral particles were extracted by porcine gastric mucin-conjugated magnetic beads (PGM-MBs) and viral RNA was quantified by real-time RT-PCR. Lower initial temperature (0 °C) significantly enhanced HHP inactivation of HuNoV compared to ambient temperature (25 °C; P < 0.05). HHP at 350 and 500 MPa at 0 °C could achieve more than 4 log10 reduction of GII.4 and GI.1 HuNoV in oysters, respectively. HHP treatments did not significantly change color or texture of oyster tissue. A 1- to 5-scale hedonic sensory evaluation on appearance, aroma, color, and overall acceptability showed that pressure-treated oysters received significantly higher quality scores than the untreated control (P < 0.05). Elevated pressure levels at 450 and 500 MPa did not significantly affect scores compared to 300 MPa at 0 °C, indicating increasing pressure level did not affect sensory acceptability of oysters. Oysters treated at 0 °C had slightly lower acceptability than the group treated at room temperature on day 1 (P < 0.05), but after 1 wk storage, no significant difference in sensory attributes and consumer desirability was observed (P > 0.05).

  20. Molecular detection of human noroviruses in influent and effluent samples from two biological sewage treatment plants in the region of Monastir, Tunisia.

    PubMed

    Hassine-Zaafrane, Mouna; Sdiri-Loulizi, Khira; Kaplon, Jérôme; Ben Salem, Imen; Pothier, Pierre; Aouni, Mahjoub; Ambert-Balay, Katia

    2014-06-01

    Noroviruses (NoVs) are responsible for numerous cases of waterborne and foodborne gastroenteritis every year. They are released in the sewage and their detection in this environment can reflect the epidemiology of the viral strains circulating in the community. A three-year (2007-2010) survey was conducted in order to evaluate the presence of human NoVs using RT-PCR in 518 sewage samples collected at the entrance and exit of two biological sewage treatment plants located in Monastir region, Tunisia. In this study, we aimed to genetically characterize the most prevalent GI and GII NoV strains, in order to obtain a rough estimate of the efficacy of disinfection treatments and to compare the results with clinical data documented in the same area during the same period. This work confirms the wide circulation and the genetic diversity of NoVs in Tunisia and the widespread distribution of NoV variants in both raw and treated wastewater. Indeed, NoV was detected in 192 (37.1%) sewage samples, among them mixed infections with group A rotavirus were detected in 125 (65.1%) cases. The genotypes of the GI NoVs were GI.1, GI.2, GI.4, GI.5, and GI of unassigned genotype (GI.UA), and the genotypes of the GII NoVs were all GII.12. This study enhances the currently poor environmental virological data gathered in Tunisia, demonstrates the benefit of environmental surveillance as a tool to determine the epidemiology of NoVs circulating in a given community, and underlines the need for the design and support of similar long-term studies in our country, in order to compensate for the absence of a national surveillance system for gastroenteric viruses.

  1. Genogroup IV and VI canine noroviruses interact with histo-blood group antigens.

    PubMed

    Caddy, Sarah; Breiman, Adrien; le Pendu, Jacques; Goodfellow, Ian

    2014-09-01

    Human noroviruses (HuNV) are a significant cause of viral gastroenteritis in humans worldwide. HuNV attaches to cell surface carbohydrate structures known as histo-blood group antigens (HBGAs) prior to internalization, and HBGA polymorphism among human populations is closely linked to susceptibility to HuNV. Noroviruses are divided into 6 genogroups, with human strains grouped into genogroups I (GI), II, and IV. Canine norovirus (CNV) is a recently discovered pathogen in dogs, with strains classified into genogroups IV and VI. Whereas it is known that GI to GIII noroviruses bind to HBGAs and GV noroviruses recognize terminal sialic acid residues, the attachment factors for GIV and GVI noroviruses have not been reported. This study sought to determine the carbohydrate binding specificity of CNV and to compare it to the binding specificities of noroviruses from other genogroups. A panel of synthetic oligosaccharides were used to assess the binding specificity of CNV virus-like particles (VLPs) and identified α1,2-fucose as a key attachment factor. CNV VLP binding to canine saliva and tissue samples using enzyme-linked immunosorbent assays (ELISAs) and immunohistochemistry confirmed that α1,2-fucose-containing H and A antigens of the HBGA family were recognized by CNV. Phenotyping studies demonstrated expression of these antigens in a population of dogs. The virus-ligand interaction was further characterized using blockade studies, cell lines expressing HBGAs, and enzymatic removal of candidate carbohydrates from tissue sections. Recognition of HBGAs by CNV provides new insights into the evolution of noroviruses and raises concerns regarding the potential for zoonotic transmission of CNV to humans. Infections with human norovirus cause acute gastroenteritis in millions of people each year worldwide. Noroviruses can also affect nonhuman species and are divided into 6 different groups based on their capsid sequences. Human noroviruses in genogroups I and II interact

  2. Genogroup IV and VI Canine Noroviruses Interact with Histo-Blood Group Antigens

    PubMed Central

    Breiman, Adrien; le Pendu, Jacques

    2014-01-01

    ABSTRACT Human noroviruses (HuNV) are a significant cause of viral gastroenteritis in humans worldwide. HuNV attaches to cell surface carbohydrate structures known as histo-blood group antigens (HBGAs) prior to internalization, and HBGA polymorphism among human populations is closely linked to susceptibility to HuNV. Noroviruses are divided into 6 genogroups, with human strains grouped into genogroups I (GI), II, and IV. Canine norovirus (CNV) is a recently discovered pathogen in dogs, with strains classified into genogroups IV and VI. Whereas it is known that GI to GIII noroviruses bind to HBGAs and GV noroviruses recognize terminal sialic acid residues, the attachment factors for GIV and GVI noroviruses have not been reported. This study sought to determine the carbohydrate binding specificity of CNV and to compare it to the binding specificities of noroviruses from other genogroups. A panel of synthetic oligosaccharides were used to assess the binding specificity of CNV virus-like particles (VLPs) and identified α1,2-fucose as a key attachment factor. CNV VLP binding to canine saliva and tissue samples using enzyme-linked immunosorbent assays (ELISAs) and immunohistochemistry confirmed that α1,2-fucose-containing H and A antigens of the HBGA family were recognized by CNV. Phenotyping studies demonstrated expression of these antigens in a population of dogs. The virus-ligand interaction was further characterized using blockade studies, cell lines expressing HBGAs, and enzymatic removal of candidate carbohydrates from tissue sections. Recognition of HBGAs by CNV provides new insights into the evolution of noroviruses and raises concerns regarding the potential for zoonotic transmission of CNV to humans. IMPORTANCE Infections with human norovirus cause acute gastroenteritis in millions of people each year worldwide. Noroviruses can also affect nonhuman species and are divided into 6 different groups based on their capsid sequences. Human noroviruses in genogroups

  3. Development of a Gaussia Luciferase-Based Human Norovirus Protease Reporter System: Cell Type-Specific Profile of Norwalk Virus Protease Precursors and Evaluation of Inhibitors

    PubMed Central

    Qu, Lin; Vongpunsawad, Sompong; Atmar, Robert L.; Prasad, B. V. Venkataram

    2014-01-01

    ABSTRACT Norwalk virus (NV) is the prototype strain of human noroviruses (HuNoVs), a group of positive-strand RNA viruses in the Caliciviridae family and the leading cause of epidemic gastroenteritis worldwide. Investigation of HuNoV replication and development of antiviral therapeutics in cell culture remain challenging tasks. Here, we present NoroGLuc, a HuNoV protease reporter system based on a fusion of NV p41 protein with a naturally secreted Gaussia luciferase (GLuc), linked by the p41/p22 cleavage site for NV protease (Pro). trans cleavage of NoroGLuc by NV Pro or Pro precursors results in release and secretion of an active GLuc. Using this system, we observed a cell type-specific activity profile of NV Pro and Pro precursors, suggesting that the activity of NV Pro is modulated by other viral proteins in the precursor forms and strongly influenced by cellular factors. NoroGLuc was also cleaved by Pro and Pro precursors generated from replication of NV stool RNA in transfected cells, resulting in a measurable increase of secreted GLuc. Truncation analysis revealed that the N-terminal membrane association domain of NV p41 is critical for NoroGLuc activity. Although designed for NV, a genogroup GI.1 norovirus, NoroGLuc also efficiently detects Pro activities from GII.3 and GII.4 noroviruses. At noncytotoxic concentrations, protease inhibitors ZnCl2 and Nα-p-tosyl-l-lysine chloromethyl ketone (TLCK) exhibited dose-dependent inhibitory effects on a GII.4 Pro by NoroGLuc assay. These results establish NoroGLuc as a pan-genogroup HuNoV protease reporter system that can be used for the study of HuNoV proteases and precursors, monitoring of viral RNA replication, and evaluation of antiviral agents. IMPORTANCE Human noroviruses are the leading cause of epidemic gastroenteritis worldwide. Currently, there are no vaccines or antiviral drugs available to counter these highly contagious viruses. These viruses are currently noncultivatable in cell culture. Here, we report

  4. Advances Toward a Norovirus Antiviral: From Classical Inhibitors to Lethal Mutagenesis

    PubMed Central

    Thorne, Lucy; Arias, Armando; Goodfellow, Ian

    2016-01-01

    Human noroviruses are a leading cause of gastroenteritis worldwide, yet there are no licensed antivirals. There is an urgent need for norovirus therapeutics, particularly for chronic infections in immunocompromised individuals, but also a potential need for prophylactic use in epidemics. Continued research has led to the identification of compounds that inhibit norovirus replication in vitro and, at least in some cases, are also effective in vivo against murine norovirus. Progress has included classical approaches targeting viral proteins and harnessing the antiviral action of interferon, strategies targeting essential host cell factors, and novel strategies exploiting the high mutation rate of noroviruses. PMID:26744429

  5. Advances Toward a Norovirus Antiviral: From Classical Inhibitors to Lethal Mutagenesis.

    PubMed

    Thorne, Lucy; Arias, Armando; Goodfellow, Ian

    2016-02-01

    Human noroviruses are a leading cause of gastroenteritis worldwide, yet there are no licensed antivirals. There is an urgent need for norovirus therapeutics, particularly for chronic infections in immunocompromised individuals, but also a potential need for prophylactic use in epidemics. Continued research has led to the identification of compounds that inhibit norovirus replication in vitro and, at least in some cases, are also effective in vivo against murine norovirus. Progress has included classical approaches targeting viral proteins and harnessing the antiviral action of interferon, strategies targeting essential host cell factors, and novel strategies exploiting the high mutation rate of noroviruses.

  6. Concurrent Detection of Human Norovirus and Bacterial Pathogens in Water Samples from an Agricultural Region in Central California Coast.

    PubMed

    Tian, Peng; Yang, David; Shan, Lei; Wang, Dapeng; Li, Qianqian; Gorski, Lisa; Lee, Bertram G; Quiñones, Beatriz; Cooley, Michael B

    2017-01-01

    Bacterial pathogens and human norovirus (HuNoV) are major cause for acute gastroenteritis caused by contaminated food and water. Public waterways can become contaminated from a variety of sources and flood after heavy rain events, leading to pathogen contamination of produce fields. We initiated a survey of several public watersheds in a major leafy green produce production region of the Central California Coast to determine the prevalence of HuNoV as well as bacterial pathogens. Moore swabs were used to collect environmental samples bi-monthly at over 30 sampling sites in the region. High prevalence of HuNoV and bacterial pathogens were detected in environmental water samples in the region. The overall detection rates of HuNoV, O157 Shiga toxin-producing Escherichia coli (STEC), non-O157 STEC, Salmonella, and Listeria were 25.58, 7.91, 9.42, 59.65, and 44.30%, respectively. The detection rates of Salmonella and L. monocytogenes were significantly higher in the spring. Fall and spring had elevated detection rates of O157 STEC. The overall detection rates of non-O157 STEC in the fall were lower than the other seasons but not significant. The overall detection rates of HuNoV were highest in fall, followed by spring and winter, with summer being lowest and significantly lower than other seasons. This study presented the first study of evaluating the correlation between the detection rate of HuNoV and the detection rates of four bacterial pathogens from environmental water. Overall, there was no significant difference in HuNoV detection rates between samples testing positive or negative for the four bacterial pathogens tested. Pathogens in animal-impacted and human-impacted areas were investigated. There were significant higher detection rates in animal-impacted areas than that of human-impacted areas for bacterial pathogens. However, there was no difference in HuNoV detection rates between these two areas. The overall detection levels of generic E. coli and detection

  7. Control of human norovirus surrogates in fresh foods by gaseous ozone and a proposed mechanism of inactivation.

    PubMed

    Predmore, Ashley; Sanglay, Gabe; Li, Jianrong; Lee, Ken

    2015-09-01

    Fresh produce is a major concern for transmission of foodborne enteric viruses as it is normally consumed with no heat treatments and minimal other processing to ensure safety. Commonly used sanitizers are ineffective at removing foodborne viruses from fresh produce. Thus the use of gaseous ozone for viral inactivation was investigated. Ozone has great potential for improved food safety because of four benefits: It is a potent sanitizer, it is effective against a wide range of microorganisms, it is permitted for food use as regulated by the U.S. FDA and several other nations, and it spontaneously decomposes to oxygen leaving no residue. This study determined the effectiveness of gaseous ozone for the sanitization of two norovirus surrogates (MNV-1 and TV) from both liquid media and popular fresh foods where viral contamination is common-lettuce and strawberries. Foods were treated with gaseous ozone at 6% wt/wt ozone in oxygen for 0, 10, 20, 30, and 40 min, and surviving viruses were quantified by viral plaque assay. Our results showed that gaseous ozone inactivated norovirus in both liquid media and fresh produce in a dose-dependent manner. These results are promising because ozone treatment significantly reduced two important norovirus surrogates in both liquid and food matrices. Viruses are generally more resistant to sanitation treatments than bacteria, thus gaseous ozone is an effective means to improve fresh produce safety. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Human Norovirus Aptamer Exhibits High Degree of Target Conformation-Dependent Binding Similar to That of Receptors and Discriminates Particle Functionality

    PubMed Central

    Bobay, Benjamin G.; Mertens, Brittany; Jaykus, Lee-Ann

    2016-01-01

    ABSTRACT Although two in vitro cultivation methods have been reported, discrimination of infectious human norovirus particles for study of viral inactivation is still a challenge, as both rely on reverse transcriptase quantitative PCR. Histo-blood group antigen (HBGA) binding assays serve as a proxy for estimation of infectious particles; however, they are costly and difficult to purify/modify. Some evidence suggests that certain nucleic acid aptamers only bind intact target proteins, thus displaying a high degree of conformation-dependent binding. The objective of this proof-of-concept study was to characterize the degree of conformation-dependent binding a human norovirus aptamer, M6-2, displayed with the capsid of the norovirus GII.4 Sydney (SYV) strain as a model. SYV capsids were exposed to heat, and aptamer, receptor (HBGA), and antibody binding was assessed. M6-2 and the receptor displayed similarly little target sequence-dependent binding (2.0% ± 1.3% and 0.5% ± 1.2% signal, respectively) compared to that of NS14 (26.4% ± 3.9%). The decay rates calculated with M6-2 and the receptor were also not statistically significantly different (P > 0.05), and dynamic light scattering and electron microscopy confirmed these observations. Ligand docking simulations revealed multiple distinct contacts of M6-2 in the N-terminal P1 and P2 domains of the viral capsid, with some residues close to receptor binding residues. These data suggest that single-stranded DNA aptamers like M6-2 display a high degree of target conformation-dependent binding. It is the first time nucleic acid aptamers have had this characteristic utilized and investigated to discern the infectivity status of viral particles, and the data suggest that other aptamers may show promise as valuable ligands in the study of other fastidious microorganisms. IMPORTANCE Human noroviruses impose a considerable health burden globally. However, study of their inactivation is still challenging with currently

  9. Evaluation of high hydrostatic pressure inactivation of human norovirus on strawberries, blueberries, raspberries and in their purees.

    PubMed

    Huang, Runze; Ye, Mu; Li, Xinhui; Ji, Lin; Karwe, Mukund; Chen, Haiqiang

    2016-04-16

    Human norovirus (HuNoV) has been an increasing concern of foodborne illness related to fresh and frozen berries. In this study, high hydrostatic pressure (HHP) inactivation of HuNoV on fresh strawberries, blueberries, and raspberries and in their purees was investigated. Porcine gastric mucin (PGM)-conjugated magnetic beads (PGM-MBs) and real-time reverse transcriptional polymerase chain reaction (RT-qPCR) were utilized for infectious HuNoV discrimination and quantification. Strawberry puree inoculated with HuNoV genogroup I.1 (GI.1) strain was HHP-treated at 450, 500 and 550 MPa for 2 min each at initial sample temperatures of 0, 4 and 20 °C. HuNoV GI.1 strain became more sensitive to HHP treatment as the temperature decreased from 20 to 0 °C. HuNoV GI.1 or genogroup II.4 (GII.4) strains were inoculated into three types of berries and their purees and treated at pressure levels from 250 to 650 MPa for 2 min at initial sample temperature of 0 °C. For the purees, the HHP condition needed to achieve >2.9 log reduction of HuNoV GI.1 strain and >4.0 log reduction of HuNoV GII.4 strain was found to be ≥ 550 MPa for 2 min at 0 °C. HHP treatment showed better inactivation effect of HuNoV on blueberries than on strawberry quarters and raspberries. HuNoV GI.1 strain was more resistant to HHP treatment than HuNoV GII.4 strain under different temperatures and environment. The physical properties and sensory qualities of HHP-treated and untreated blueberries and the three types of berry purees were evaluated. Color, pH and viscosity of blueberries and three berry purees showed no or slight changes after HHP treatment. Sensory evaluation demonstrated that HHP treatment of 550 MPa for 2 min at 0 °C did not significantly reduced the sensory qualities of three berry purees. The results demonstrated that the HHP treatment of 550 MPa for 2 min at 0 °C could be a potential nonthermal intervention for HuNoV in berry purees without adversely affecting their sensory qualities

  10. Quantitative farm-to-fork human norovirus exposure assessment of individually quick frozen raspberries and raspberry puree.

    PubMed

    Jacxsens, L; Stals, A; De Keuckelaere, A; Deliens, B; Rajkovic, A; Uyttendaele, M

    2017-02-02

    A quantitative human norovirus (NoV) exposure model describing transmission of NoV during pre-harvest, harvest and further processing of soft red fruits exemplified by raspberries is presented. The outcomes of the model demonstrate the presence of NoV in raspberry puree or individual quick frozen (IQF) raspberry fruits and were generated by Monte Carlo simulations by combining GoldSim® and @Risk® software. Input data were collected from scientific literature, observational studies and assumptions. NoV contamination of soft red fruits is assumed to take place at farms by application of contaminated water for pesticides dilution or by berries' pickers shedding NoV. The model was built simulating that a collection center received berries from ten farms with a total of 245 food handlers picking soft red fruits during a 10-hour day shift. Given 0, 5 and 20 out of 245 berries' pickers were shedding NoV, these conditions were calculated to result in a mean NoV contamination of respectively 0.47, 14.1 and 36.2 NoV particles per kg raspberries in case all raspberries are mixed to one day-batch of 11tons. The NoV contamination of the fruits was mainly driven by the route of NoV shedding food pickers (95.8%) rather than by spraying contaminated pesticide water (4.2%) (baseline scenario with 5 shedding pickers and contaminated pesticide water). Inclusion of appropriate hand washing procedures or hand washing followed by hand disinfection resulted in estimated reductions of the mean NoV levels from 14.1 to 0.16 and 0.17 NoV particles per kg raspberries, respectively, for the baseline scenario with 5 out of 245 food pickers shedding NoV. The use of a mild heat treatment (30s at 75°C) during further processing of berries to purees was noted to reduce mean NoV levels substantially from 14.1 to 0.2 NoV particles per kg raspberry puree. For IQF raspberries, the NoV contamination is heterogeneously distributed and resulted in a mean contamination of 3.1 NoV particles per 250g

  11. Differences in the binding of human norovirus to and from romaine lettuce and raspberries by water and electrolyzed waters.

    PubMed

    Tian, Peng; Yang, David; Mandrell, Robert

    2011-08-01

    Food contamination by human norovirus (hNoV) is a major cause of gastrointestinal disease. We evaluated the effectiveness of removing inoculated hNoV from the surfaces of raspberries and romaine lettuce by a simple wash in tap water and in different forms of electrolyzed water (EW), including acidic EW (AEW), neutral EW (NEW), and basic EW (BEW). A simple rinsing or soaking in water was able to remove >95% of hNoV from surface-inoculated raspberries. In contrast, only 75% of hNoV was removed from surface-inoculated romaine lettuce by rinsing in tap water. An AEW wash enhanced the binding of hNoV to raspberries and lettuce. Only 7.5% (±10%) and 4% (±3.1%) of hNoV were removed by AEW wash from surface-inoculated raspberries and lettuce, respectively. When raspberries and lettuce were prewashed with NEW or BEW prior to surface inoculation, an AEW wash likewise resulted in significantly less removal of hNoV compared with untreated samples. A prewash with AEW significantly decreased the removal of hNoV from raspberries and lettuce when they were washed with NEW, from 90.6 to 51% and from 76 to 51.3% , respectively. There are minimal or no improvements gained by use of any of the EWs instead of a regular tap water wash in removal of hNoV from produce. However, use of AEW shows a significant decrease in the removal of hNoV from contaminated produce compared with other water rinses. The ability to remove hNoV from different types of produce varies, possibly due to differences among types of ligand-like molecules that bind hNoV. The distribution of hNoV on raspberries and lettuce was studied using recombinant Norwalk-like particles (rNVLP). By immunofluorescence microscopy, we were able to observe binding of rNVLP only to vein areas of romaine lettuce, suggesting that the virus was binding to specific molecules in these areas. Random binding of rNVLP occurred only with raspberries prewashed with AEW or washed with AEW.

  12. Surfactant enhanced disinfection of the human norovirus surrogate, tulane virus with organic acids and surfactant

    USDA-ARS?s Scientific Manuscript database

    Human infection with foodborne viruses can occur following consumption of contaminated food, person-to-person body contact, or release of aerosols. Combinatorial treatments of surfactants and organic acids may have synergistic or additive mechanisms to inactivate foodborne viruses and prevent outbr...

  13. Multiple consecutive norovirus infections in the first 2 years of life.

    PubMed

    Blazevic, Vesna; Malm, Maria; Salminen, Marjo; Oikarinen, Sami; Hyöty, Heikki; Veijola, Riitta; Vesikari, Timo

    2015-12-01

    Studies investigating the magnitude and breath of protective immune responses after primary and subsequent norovirus infections in pediatric populations are limited. We investigated incidence of norovirus infections and serological responses in a child from longitudinal stool and serum samples collected from birth to 2 years of age. Four consecutive infections with distinct genotypes of norovirus were detected. Serum antibodies were genotype-specific offering no protection to reinfection with heterologous virus. This study describes norovirus-specific serological responses in a child with four consecutive norovirus infection during the first 2 years of life. The response is type-specific and does not protect from a subsequent infection with a heterologous virus. • Correlates of protection to norovirus infection and disease are not yet determined, and most of the presently available data concern adult population. • This manuscript describes serological immune responses after primary and subsequent infections in a child during the first 2 years of life.

  14. Evaluation of a Microarray for Genotyping Noroviruses

    EPA Science Inventory

    Noroviruses that infect humans are divided into three genogroups based upon their sequence diversity. Of these, genogroups I and II have been identified as leading causes of waterborne disease outbreaks worldwide and are frequently found in rivers and lakes that serve as drinkin...

  15. Evaluation of a Microarray for Genotyping Noroviruses

    EPA Science Inventory

    Noroviruses that infect humans are divided into three genogroups based upon their sequence diversity. Of these, genogroups I and II have been identified as leading causes of waterborne disease outbreaks worldwide and are frequently found in rivers and lakes that serve as drinkin...

  16. Norovirus in Captive Lion Cub (Panthera leo)

    PubMed Central

    Campolo, Marco; Lorusso, Eleonora; Cavicchio, Paolo; Camero, Michele; Bellacicco, Anna L.; Decaro, Nicola; Elia, Gabriella; Greco, Grazia; Corrente, Marialaura; Desario, Costantina; Arista, Serenella; Banyai, Krisztián; Koopmans, Marion; Buonavoglia, Canio

    2007-01-01

    African lions (Panthera leo) are susceptible to viral diseases of domestic carnivores, including feline calicivirus infection. We report the identification of a novel enteric calicivirus, genetically related to human noroviruses of genogroup IV, in a lion cub that died of severe hemorrhagic enteritis. PMID:18214183

  17. Application of porcine gastric mucin-conjugated magnetic beads and polyethylene glycol goncentration and detection of human noroviruses from green onion and grape

    USDA-ARS?s Scientific Manuscript database

    Objective: To set up detection methods for norovirus in fruits and vegetables by using porcine gastric mucin-conjugated magnetic beads (PGM-MB) and polyethylene glycol 8000 (PEG8000) concentrating and detecting the norovirus in green onion and grape. Methods: The highest virus dilution given a posit...

  18. Electron beam inactivation of Tulane virus on fresh produce, and mechanism of inactivation of human norovirus surrogates by electron beam irradiation.

    PubMed

    Predmore, Ashley; Sanglay, Gabriel C; DiCaprio, Erin; Li, Jianrong; Uribe, R M; Lee, Ken

    2015-04-02

    Ionizing radiation, whether by electron beams or gamma rays, is a non-thermal processing technique used to improve the microbial safety and shelf-life of many different food products. This technology is highly effective against bacterial pathogens, but data on its effect against foodborne viruses is limited. A mechanism of viral inactivation has been proposed with gamma irradiation, but no published study discloses a mechanism for electron beam (e-beam). This study had three distinct goals: 1) evaluate the sensitivity of a human norovirus surrogate, Tulane virus (TV), to e-beam irradiation in foods, 2) compare the difference in sensitivity of TV and murine norovirus (MNV-1) to e-beam irradiation, and 3) determine the mechanism of inactivation of these two viruses by e-beam irradiation. TV was reduced from 7 log10 units to undetectable levels at target doses of 16 kGy or higher in two food matrices (strawberries and lettuce). MNV-1 was more resistant to e-beam treatment than TV. At target doses of 4 kGy, e-beam provided a 1.6 and 1.2 log reduction of MNV-1 in phosphate buffered saline (PBS) and Dulbecco's Modified Eagle Medium (DMEM), compared to a 1.5 and 1.8 log reduction of TV in PBS and Opti-MEM, respectively. Transmission electron microscopy revealed that increased e-beam doses negatively affected the structure of both viruses. Analysis of viral proteins by SDS-PAGE found that irradiation also degraded viral proteins. Using RT-PCR, irradiation was shown to degrade viral genomic RNA. This suggests that the mechanism of inactivation of e-beam was likely the same as gamma irradiation as the damage to viral constituents led to inactivation. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Norovirus genetic diversity and evolution: implications for antiviral therapy.

    PubMed

    Rocha-Pereira, Joana; Van Dycke, Jana; Neyts, Johan

    2016-10-01

    Human noroviruses are the leading cause of foodborne illness causing both acute and chronic gastroenteritis. In recent years, a number of vaccine candidates entered (pre-) clinical development and the first efforts to develop antiviral therapy have been made. We here discuss aspects of norovirus genetic evolution, persistence in immunocompromised patients as well as the risk and potential consequences of resistance development toward future antiviral drugs. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Chronic norovirus infection in a transplant patient successfully treated with enterally administered immune globulin.

    PubMed

    Chagla, Zain; Quirt, Jaclyn; Woodward, Kevin; Neary, John; Rutherford, Candace

    2013-09-01

    Norovirus infection causes a significant burden of morbidity and (in the developing world) mortality. In immunocompromised hosts, norovirus infection can become chronic, with devastating consequences. Unfortunately, therapeutic options for chronic disease are unproven, and treatment is largely supportive. We report a case of norovirus infection causing debilitating chronic gastroenteritis in a transplant patient that responded to a short course of enterally administered human immune globulin.

  1. Reporting and Surveillance for Norovirus Outbreaks

    MedlinePlus

    ... Norovirus Infection, National Institutes of Health NoroCORE Food Virology Reporting and Surveillance for Norovirus Recommend on Facebook ... Norovirus Infection, National Institutes of Health NoroCORE Food Virology File Formats Help: How do I view different ...

  2. Molecular characteristics of noroviruses genogroup I and genogroup II detected in patients with acute gastroenteritis.

    PubMed

    Ham, Heejin; Oh, Seah; Seung, Hyunjung; Jo, Sukju

    2015-03-01

    Noroviruses are the leading cause of epidemic gastroenteritis, including foodborne outbreak, in Korea. The prevalence of human noroviruses was studied in diarrheal stool samples of patients with acute gastroenteritis by conventional duplex reverse transcription (RT)-PCR. Diarrheal stool samples were collected from 1,685 patients from the local hospitals in Seoul. The prevalence of the noroviruses was 22.8% (222/972 patients) in 2012 and 11.2% (80/713 patients) in 2013, with a total of 17.9% (302/1,685 patients). Genotyping was performed on 302 norovirus-positive stool samples to reveal 5.6% prevalence of genogroup I (GI) (17/302) and 94.4% prevalence of genogroup II (GII) (285/302). The patients with norovirus-associated acute gastroenteritis mostly showed prevalence of GII norovirus, especially GII.4 (64.6%; 195/302).

  3. Oxadiazole-Based Cell Permeable Macrocyclic Transition State Inhibitors of Norovirus 3CL Protease.

    PubMed

    Damalanka, Vishnu C; Kim, Yunjeong; Alliston, Kevin R; Weerawarna, Pathum M; Galasiti Kankanamalage, Anushka C; Lushington, Gerald H; Mehzabeen, Nurjahan; Battaile, Kevin P; Lovell, Scott; Chang, Kyeong-Ok; Groutas, William C

    2016-03-10

    Human noroviruses are the primary causative agents of acute gastroenteritis and a pressing public health burden worldwide. There are currently no vaccines or small molecule therapeutics available for the treatment or prophylaxis of norovirus infections. Norovirus 3CL protease plays a vital role in viral replication by generating structural and nonstructural proteins via the cleavage of the viral polyprotein. Thus, molecules that inhibit the viral protease may have potential therapeutic value. We describe herein the structure-based design, synthesis, and in vitro and cell-based evaluation of the first class of oxadiazole-based, permeable macrocyclic inhibitors of norovirus 3CL protease.

  4. Mapping Broadly Reactive Norovirus Genogroup I and II Monoclonal Antibodies

    PubMed Central

    Crawford, Sue E.; Ajami, Nadim; Parker, Tracy Dewese; Kitamoto, Noritoshi; Natori, Katsuro; Takeda, Naokazu; Tanaka, Tomoyuki; Kou, Baijun; Atmar, Robert L.

    2014-01-01

    Noroviruses are responsible for most acute nonbacterial epidemic outbreaks of gastroenteritis worldwide. To develop cross-reactive monoclonal antibodies (MAbs) for rapid identification of genogroup I and II (GI and GII) noroviruses (NoVs) in field specimens, mice were immunized with baculovirus-expressed recombinant virus-like particles (VLPs) corresponding to NoVs. Nine MAbs against the capsid protein were identified that detected both GI and GII NoV VLPs. These MAbs were tested in competition enzyme-linked immunosorbent assays (ELISAs) to identify common epitope reactivities to GI and GII VLPs. Patterns of competitive reactivity placed these MAbs into two epitope groups (groups 1 and 2). Epitopes for MAbs NV23 and NS22 (group 1) and MAb F120 (group 2) were mapped to a continuous region in the C-terminal P1 subdomain of the capsid protein. This domain is within regions previously defined to contain cross-reactive epitopes in GI and GII viruses, suggesting that common epitopes are clustered within the P1 domain of the capsid protein. Further characterization in an accompanying paper (B. Kou et al., Clin Vaccine Immunol 22:160–167, 2015, http://dx.doi.org/10.1128/CVI.00519-14) revealed that MAb NV23 (epitope group 1) is able to detect GI and GII viruses in stool. Inclusion of the GI and GII cross-reactive MAb NV23 in antigen detection assays may facilitate the identification of GI and GII human noroviruses in stool samples as causative agents of outbreaks and sporadic cases of gastroenteritis worldwide. PMID:25428246

  5. Mapping broadly reactive norovirus genogroup I and II monoclonal antibodies.

    PubMed

    Crawford, Sue E; Ajami, Nadim; Parker, Tracy Dewese; Kitamoto, Noritoshi; Natori, Katsuro; Takeda, Naokazu; Tanaka, Tomoyuki; Kou, Baijun; Atmar, Robert L; Estes, Mary K

    2015-02-01

    Noroviruses are responsible for most acute nonbacterial epidemic outbreaks of gastroenteritis worldwide. To develop cross-reactive monoclonal antibodies (MAbs) for rapid identification of genogroup I and II (GI and GII) noroviruses (NoVs) in field specimens, mice were immunized with baculovirus-expressed recombinant virus-like particles (VLPs) corresponding to NoVs. Nine MAbs against the capsid protein were identified that detected both GI and GII NoV VLPs. These MAbs were tested in competition enzyme-linked immunosorbent assays (ELISAs) to identify common epitope reactivities to GI and GII VLPs. Patterns of competitive reactivity placed these MAbs into two epitope groups (groups 1 and 2). Epitopes for MAbs NV23 and NS22 (group 1) and MAb F120 (group 2) were mapped to a continuous region in the C-terminal P1 subdomain of the capsid protein. This domain is within regions previously defined to contain cross-reactive epitopes in GI and GII viruses, suggesting that common epitopes are clustered within the P1 domain of the capsid protein. Further characterization in an accompanying paper (B. Kou et al., Clin Vaccine Immunol 22:160-167, 2015, http://dx.doi.org/10.1128/CVI.00519-14) revealed that MAb NV23 (epitope group 1) is able to detect GI and GII viruses in stool. Inclusion of the GI and GII cross-reactive MAb NV23 in antigen detection assays may facilitate the identification of GI and GII human noroviruses in stool samples as causative agents of outbreaks and sporadic cases of gastroenteritis worldwide. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  6. Self-Assembly of the Recombinant Capsid Protein of a Swine Norovirus into Virus-Like Particles and Evaluation of Monoclonal Antibodies Cross-Reactive with a Human Strain from Genogroup II▿

    PubMed Central

    Almanza, Horacio; Cubillos, Carolina; Angulo, Iván; Mateos, Francisco; Castón, José R.; van der Poel, Wim H. M.; Vinje, Jan; Bárcena, Juan; Mena, Ignacio

    2008-01-01

    Noroviruses (NoVs) are responsible for the majority of gastroenteritis outbreaks in humans. Recently, NoV strains which are genetically closely related to human genogroup II (GII) NoVs have been detected in fecal specimens from swine. These findings have raised concern about the possible role of pigs as reservoirs for NoVs that could infect humans. To better understand the epidemiology of swine NoVs in both the swine and the human populations, rapid immunoassays are needed. In this study, baculovirus recombinants were generated to express the capsid gene of a swine NoV GII genotype 11 (GII.11) strain which self-assembled into virus-like particles (VLPs). Subsequently, the purified VLPs were used to evoke monoclonal antibodies (MAbs) in mice. A panel of eight promising MAbs was obtained and evaluated for their ability to bind to heterologous VLPs, denaturated antigens, and truncated capsid proteins. The MAbs could be classified into two groups: two MAbs that recognized linear epitopes located at the amino-terminal half (shell domain) of the swine NoV GII.11 VLPs and that cross-reacted with human GII.4 NoV VLPs. The other six MAbs bound to conformational epitopes and did not cross-react with the human GII.4 VLPs. To our knowledge, this is the first report on the characterization of MAbs against swine NoVs. The swine NoV VLPs and the MAbs described here may be further used for the design of diagnostic reagents that could help increase our knowledge of the prevalence of NoV infections in pigs and the possible role of pigs as reservoirs for NoVs. PMID:18842943

  7. Virucidal Activity of Fogged Chlorine Dioxide- and Hydrogen Peroxide-Based Disinfectants against Human Norovirus and Its Surrogate, Feline Calicivirus, on Hard-to-Reach Surfaces.

    PubMed

    Montazeri, Naim; Manuel, Clyde; Moorman, Eric; Khatiwada, Janak R; Williams, Leonard L; Jaykus, Lee-Ann

    2017-01-01

    Human norovirus (NoV) is the leading cause of foodborne illnesses in the United States. Norovirus is shed in high numbers in the feces and vomitous of infected individuals. Contact surfaces contaminated with bodily fluids harboring infectious virus particles serve as vehicles for pathogen transmission. Environmental stability of NoV and its resistance to many conventional disinfectants necessitate effective inactivation strategies to control the spread of virus. We investigated the efficacy of two commercial disinfectants, hydrogen peroxide (7.5%) and a chlorine dioxide (0.2%)-surfactant-based product using a fogging delivery system against human NoV GI.6 and GII.4 Sydney strains as well as the cultivable surrogate, feline calicivirus (FCV) dried on stainless steel coupons. Log10 reductions in human NoV and FCV were calculated utilizing RNase RT-qPCR and infectivity (plaque) assay, respectively. An improved antiviral activity of hydrogen peroxide as a function of disinfectant formulation concentration in the atmosphere was observed against both GII.4 and FCV. At 12.4 ml/m(3), hydrogen peroxide achieved a respective 2.5 ± 0.1 and 2.7 ± 0.3 log10 reduction in GI.6 and GII.4 NoV genome copies, and a 4.3 ± 0.1 log10 reduction in infectious FCV within 5 min. At the same disinfectant formulation concentration, chlorine dioxide-surfactant-based product resulted in a respective 1.7 ± 0.2, 0.6 ± 0.0, and 2.4 ± 0.2 log10 reduction in GI.6, GII.4, and FCV within 10 min; however, increasing the disinfectant formulation concentration to 15.9 ml/m(3) negatively impacted its efficacy. Fogging uniformly delivered the disinfectants throughout the room, and effectively decontaminated viruses on hard-to-reach surfaces. Hydrogen peroxide delivered by fog showed promising virucidal activity against FCV by meeting the United States EPA 4-log10 reduction criteria for an anti-noroviral disinfectant; however, fogged chlorine dioxide-surfactant-based product did not achieve a 4-log10

  8. Virucidal Activity of Fogged Chlorine Dioxide- and Hydrogen Peroxide-Based Disinfectants against Human Norovirus and Its Surrogate, Feline Calicivirus, on Hard-to-Reach Surfaces

    PubMed Central

    Montazeri, Naim; Manuel, Clyde; Moorman, Eric; Khatiwada, Janak R.; Williams, Leonard L.; Jaykus, Lee-Ann

    2017-01-01

    Human norovirus (NoV) is the leading cause of foodborne illnesses in the United States. Norovirus is shed in high numbers in the feces and vomitous of infected individuals. Contact surfaces contaminated with bodily fluids harboring infectious virus particles serve as vehicles for pathogen transmission. Environmental stability of NoV and its resistance to many conventional disinfectants necessitate effective inactivation strategies to control the spread of virus. We investigated the efficacy of two commercial disinfectants, hydrogen peroxide (7.5%) and a chlorine dioxide (0.2%)-surfactant-based product using a fogging delivery system against human NoV GI.6 and GII.4 Sydney strains as well as the cultivable surrogate, feline calicivirus (FCV) dried on stainless steel coupons. Log10 reductions in human NoV and FCV were calculated utilizing RNase RT-qPCR and infectivity (plaque) assay, respectively. An improved antiviral activity of hydrogen peroxide as a function of disinfectant formulation concentration in the atmosphere was observed against both GII.4 and FCV. At 12.4 ml/m3, hydrogen peroxide achieved a respective 2.5 ± 0.1 and 2.7 ± 0.3 log10 reduction in GI.6 and GII.4 NoV genome copies, and a 4.3 ± 0.1 log10 reduction in infectious FCV within 5 min. At the same disinfectant formulation concentration, chlorine dioxide-surfactant-based product resulted in a respective 1.7 ± 0.2, 0.6 ± 0.0, and 2.4 ± 0.2 log10 reduction in GI.6, GII.4, and FCV within 10 min; however, increasing the disinfectant formulation concentration to 15.9 ml/m3 negatively impacted its efficacy. Fogging uniformly delivered the disinfectants throughout the room, and effectively decontaminated viruses on hard-to-reach surfaces. Hydrogen peroxide delivered by fog showed promising virucidal activity against FCV by meeting the United States EPA 4-log10 reduction criteria for an anti-noroviral disinfectant; however, fogged chlorine dioxide-surfactant-based product did not achieve a 4-log10

  9. Anti-Norovirus Therapeutics: A Patent Review (2010–2015)

    PubMed Central

    Galasiti Kankanamalage, Anushka C.; Weerawarna, Pathum M.; Kim, Yunjeong; Chang, Kyeong-Ok; Groutas, William C.

    2016-01-01

    Introduction Human noroviruses are the primary causative agents of acute gastroenteritis and are a pressing public health burden worldwide. There are currently no vaccines or small molecule therapeutics available for the treatment or prophylaxis of norovirus infections. An improved understanding of norovirus biology, as well as the pathogenic mechanisms underlying the disease, has provided the impetus for a range of intense exploratory drug discovery efforts targeting viral and host factors. Areas covered An overview of norovirus inhibitors disclosed in the patent literature (2010-present) and Clinicaltrials.gov is presented. The review is further enriched and supplemented by recent literature reports. Expert opinion Seminal discoveries made in recent years, including a better understanding of the pathobiology and life cycle of norovirus, the identification and targeting of multiple viral and host factors, the advent of a replicon system and a small animal model for the preclinical evaluation of lead compounds, and the availability of high resolution X-ray crystal structures that can be utilized in structure-based drug design and lead optimization campaigns, collectively suggest that a small molecule therapeutic and prophylactic for norovirus infection is likely to emerge in the not too distant future. PMID:26881878

  10. Nanobody Binding to a Conserved Epitope Promotes Norovirus Particle Disassembly

    PubMed Central

    Koromyslova, Anna D.

    2014-01-01

    ABSTRACT Human noroviruses are icosahedral single-stranded RNA viruses. The capsid protein is divided into shell (S) and protruding (P) domains, which are connected by a flexible hinge region. There are numerous genetically and antigenically distinct noroviruses, and the dominant strains evolve every other year. Vaccine and antiviral development is hampered by the difficulties in growing human norovirus in cell culture and the continually evolving strains. Here, we show the X-ray crystal structures of human norovirus P domains in complex with two different nanobodies. One nanobody, Nano-85, was broadly reactive, while the other, Nano-25, was strain specific. We showed that both nanobodies bound to the lower region on the P domain and had nanomolar affinities. The Nano-85 binding site mainly comprised highly conserved amino acids among the genetically distinct genogroup II noroviruses. Several of the conserved residues also were recognized by a broadly reactive monoclonal antibody, which suggested this region contained a dominant epitope. Superposition of the P domain nanobody complex structures into a cryoelectron microscopy particle structure revealed that both nanobodies bound at occluded sites on the particles. The flexible hinge region, which contained ∼10 to 12 amino acids, likely permitted a certain degree of P domain movement on the particles in order to accommodate the nanobodies. Interestingly, the Nano-85 binding interaction with intact particles caused the particles to disassemble in vitro. Altogether, these results suggested that the highly conserved Nano-85 binding epitope contained a trigger mechanism for particle disassembly. Principally, this epitope represents a potential site of norovirus vulnerability. IMPORTANCE We characterized two different nanobodies (Nano-85 and Nano-25) that bind to human noroviruses. Both nanobodies bound with high affinities to the lower region of the P domain, which was occluded on intact particles. Nano-25 was

  11. Identification of a novel cellular target and a co-factor for norovirus infection – B cells & commensal bacteria

    PubMed Central

    Karst, Stephanie M

    2015-01-01

    Human noroviruses are a leading cause of gastroenteritis worldwide but research on these important enteric pathogens has long been restricted by their uncultivability. Extensive efforts to infect intestinal epithelial cells with murine and human noroviruses in vitro have been thus far unsuccessful while murine noroviruses efficiently and lytically infect innate immune cells including macrophages and dendritic cells. We have recently discovered that murine and human noroviruses infect B cells in vitro. The nature of B cell infection was distinct from innate immune cell infection in that mature B cells were infected noncytopathically in contrast to the lytic infection of macrophages and dendritic cells. Human norovirus infection of B cells was facilitated by commensal bacteria expressing an appropriate histo-blood group antigen. Importantly, we used the mouse model of norovirus infection to confirm that Peyer's patch B cells are infected, and that commensal bacteria stimulate infection, in vivo. PMID:25997033

  12. Identification of a novel cellular target and a co-factor for norovirus infection - B cells & commensal bacteria.

    PubMed

    Karst, Stephanie M

    2015-07-04

    Human noroviruses are a leading cause of gastroenteritis worldwide but research on these important enteric pathogens has long been restricted by their uncultivability. Extensive efforts to infect intestinal epithelial cells with murine and human noroviruses in vitro have been thus far unsuccessful while murine noroviruses efficiently and lytically infect innate immune cells including macrophages and dendritic cells. We have recently discovered that murine and human noroviruses infect B cells in vitro. The nature of B cell infection was distinct from innate immune cell infection in that mature B cells were infected noncytopathically in contrast to the lytic infection of macrophages and dendritic cells. Human norovirus infection of B cells was facilitated by commensal bacteria expressing an appropriate histo-blood group antigen. Importantly, we used the mouse model of norovirus infection to confirm that Peyer's patch B cells are infected, and that commensal bacteria stimulate infection, in vivo.

  13. Two-Year Systematic Study To Assess Norovirus Contamination in Oysters from Commercial Harvesting Areas in the United Kingdom

    PubMed Central

    Gustar, Nicole E.; Powell, Andrew L.; Hartnell, Rachel E.; Lees, David N.

    2012-01-01

    The contamination of bivalve shellfish with norovirus from human fecal sources is recognized as an important human health risk. Standardized quantitative methods for the detection of norovirus in molluscan shellfish are now available, and viral standards are being considered in the European Union and internationally. This 2-year systematic study aimed to investigate the impact of the application of these methods to the monitoring of norovirus contamination in oyster production areas in the United Kingdom. Twenty-four monthly samples of oysters from 39 United Kingdom production areas, chosen to represent a range of potential contamination risk, were tested for norovirus genogroups I and II by using a quantitative real-time reverse transcription (RT)-PCR method. Norovirus was detected in 76.2% (643/844) of samples, with all sites returning at least one positive result. Both prevalences (presence or absence) and norovirus levels varied markedly between sites. However, overall, a marked winter seasonality of contamination by both prevalence and quantity was observed. Correlations were found between norovirus contamination and potential risk indicators, including harvesting area classifications, Escherichia coli scores, and environmental temperatures. A predictive risk score for norovirus contamination was developed by using a combination of these factors. In summary, this study, the largest of its type undertaken to date, provides a systematic analysis of norovirus contamination in commercial oyster production areas in the United Kingdom. The data should assist risk managers to develop control strategies to reduce the risk of human illness resulting from norovirus contamination of bivalve molluscs. PMID:22685151

  14. Dose and Size-Dependent Antiviral Effects of Silver Nanoparticles on Feline Calicivirus, a Human Norovirus Surrogate.

    PubMed

    Bekele, Aschalew Z; Gokulan, Kuppan; Williams, Katherine M; Khare, Sangeeta

    2016-05-01

    Silver nanoparticles (AgNPs) as antibacterial agents are incorporated in many consumer products, while the use as antiviral agents is an ongoing area of research. We evaluated the antiviral properties of AgNPs of variable sizes (10, 75, and 110 nm) and doses (25, 50, and 100 μg/mL) at different contact time points against feline calicivirus (FCV), a surrogate for norovirus. Antiviral effects of the AgNPs were determined by comparing the infectivity of FCV, the appearance of cytopathic effects (CPEs), and the integrity of the viral capsid protein in viral suspension treated with AgNPs with the untreated controls. The 10 nm AgNPs at 50 and 100 μg/mL concentrations inactivated the FCV beyond the limit of detection, resulting in a decrease of up to 6.5 log10 viral titer, prevented development of CPEs, and reduction in the western blot band signal of the viral capsid protein. No significant antiviral effect was observed for the 75 and 110 nm AgNPs. Conclusions and Applications: These results demonstrate that the antiviral effects of AgNPs are both size and dose dependent, thus potential applications of AgNPs as antiviral agents to prevent contamination of foodborne viruses need to consider size and dose effects.

  15. Molecular epidemiology of oyster-related human noroviruses and their global genetic diversity and temporal-geographical distribution from 1983 to 2014.

    PubMed

    Yu, Yongxin; Cai, Hui; Hu, Linghao; Lei, Rongwei; Pan, Yingjie; Yan, Shuling; Wang, Yongjie

    2015-11-01

    Noroviruses (NoVs) are a leading cause of epidemic and sporadic cases of acute gastroenteritis worldwide. Oysters are well recognized as the main vectors of environmentally transmitted NoVs, and disease outbreaks linked to oyster consumption have been commonly observed. Here, to quantify the genetic diversity, temporal distribution, and circulation of oyster-related NoVs on a global scale, 1,077 oyster-related NoV sequences deposited from 1983 to 2014 were downloaded from both NCBI GenBank and the NoroNet outbreak database and were then screened for quality control. A total of 665 sequences with reliable information were obtained and were subsequently subjected to genotyping and phylogenetic analyses. The results indicated that the majority of oyster-related NoV sequences were obtained from coastal countries and regions and that the numbers of sequences in these regions were unevenly distributed. Moreover, >80% of human NoV genotypes were detected in oyster samples or oyster-related outbreaks. A higher proportion of genogroup I (GI) (34%) was observed for oyster-related sequences than for non-oyster-related outbreaks, where GII strains dominated with an overwhelming majority of >90%, indicating that the prevalences of GI and GII are different in humans and oysters. In addition, a related convergence of the circulation trend was found between oyster-related NoV sequences and human pandemic outbreaks. This suggests that oysters not only act as a vector of NoV through environmental transmission but also serve as an important reservoir of human NoVs. These results highlight the importance of oysters in the persistence and transmission of human NoVs in the environment and have important implications for the surveillance of human NoVs in oyster samples.

  16. Molecular epidemiology of norovirus associated with gastroenteritis and emergence of norovirus GII.4 variant 2012 in Japanese pediatric patients.

    PubMed

    Thongprachum, Aksara; Chan-it, Wisoot; Khamrin, Pattara; Saparpakorn, Patchreenart; Okitsu, Shoko; Takanashi, Sayaka; Mizuguchi, Masashi; Hayakawa, Satoshi; Maneekarn, Niwat; Ushijima, Hiroshi

    2014-04-01

    In late 2012, an outbreak of acute gastroenteritis due to norovirus variant Sydney_2012 occurred and have been reported from many counties. In this study, we described surveillance study of the incidence of norovirus infections among Japanese pediatric patients in association with gastroenteritis and investigated the antigenic change of the new variant Sydney_2012 circulated in Japanese populations. A total of 2381 fecal specimens collected from children with acute gastroenteritis in Hokkaido, Tokyo, Shizuoka, Kyoto, Osaka, and Saga from 2009 to 2013 were examined for norovirus and further analyzed molecularly. A high proportion (39.3%) of norovirus positive samples and several genotypes were detected. Norovirus GII.4 dominated over other genotypes (71.4%). The Den_Haag_2006b (43.2%) was detected as the predominant variant and co-circulated with New_Orleans_2009 (17.8%) until March 2012. Subsequently, they were displaced by Sydney_2012. The Sydney_2012 variant has been responsible for the majority of norovirus infections in 2012-2013 (85.7%). Although Sydney_2012 variant has a common ancestor with New_Orleans_2009 variant, analysis of P2 sub-domain showed a high level of diversity in comparison with other variants in four amino acid changes at the antigenic sites. The change in particular residue 393 of new variant may affect HBGA recognition. Analysis of noroviruses circulating in the past 4years revealed a change of predominant variant of norovirus GII.4 in each epidemic season. The change of amino acid in putative epitopes may have led the virus escape from the existing herd immunity and explain the increase of new variant outbreaks.

  17. Atmospheric cold plasma iactivation of norovirus surrogates and native microbiota on blueberries

    USDA-ARS?s Scientific Manuscript database

    Cold plasma (CP) is an emerging, novel, nonthermal technology that can be used for surface decontamination of foods. This study investigated CP technology for the nonthermal inactivation of the human norovirus surrogates, Tulane virus (TV) and Murine Norovirus (MNV), as well as for background microb...

  18. Inactivation of HAV and norovirus surrogates within raw shellfish and other foods

    USDA-ARS?s Scientific Manuscript database

    High pressure processing can inactivate hepatitis A virus, (HAV) and the human norovirus surrogates, feline calicivirus (FCV) and murine norovirus (MNV), in foods such as oysters, strawberries, and green onions. A 5-min 400-Megapascals (MPa) treatment at 5 degrees C and a 1–min 400-MPa treatment at ...

  19. Novel Platform Technologies for Analysis of Norovirus Contamination of Sea Food

    USDA-ARS?s Scientific Manuscript database

    The study of human norovirus (NoVs) replication in vitro would be a highly useful tool to virologists and immunologists. For this reason, we have searched for new approaches to determine viability of noroviruses in food samples (especially seafood). Our research team has multiple years of experien...

  20. Critical review of norovirus surrogates in food safety research: rationale for considering volunteer studies

    USDA-ARS?s Scientific Manuscript database

    The inability to propagate human norovirus (NoV) or to clearly differentiate infectious from noninfectious virus particles have led to the use of surrogate viruses, like feline calicivirus (FCV) and murine norovirus-1 (MNV), which are propagatable in cell culture. The use of surrogates is predicate...

  1. Digital PCR for Quantifying Norovirus in Oysters Implicated in Outbreaks, France

    PubMed Central

    Polo, David; Schaeffer, Julien; Fournet, Nelly; Le Saux, Jean-Claude; Parnaudeau, Sylvain; McLeod, Catherine

    2016-01-01

    Using samples from oysters clearly implicated in human disease, we quantified norovirus levels by using digital PCR. Concentrations varied from 43 to 1,170 RNA copies/oyster. The analysis of frozen samples from the production area showed the presence of norovirus 2 weeks before consumption. PMID:27869597

  2. Murine Norovirus 1 Infection Is Associated with Histopathological Changes in Immunocompetent Hosts, but Clinical Disease Is Prevented by STAT1-Dependent Interferon Responses▿

    PubMed Central

    Mumphrey, Shannon M.; Changotra, Harish; Moore, Tara N.; Heimann-Nichols, Ellen R.; Wobus, Christiane E.; Reilly, Michael J.; Moghadamfalahi, Mana; Shukla, Deepti; Karst, Stephanie M.

    2007-01-01

    Human noroviruses are the major cause of nonbacterial epidemic gastroenteritis worldwide. However, little is known regarding their pathogenesis or the immune responses that control them because until recently there has been no small animal model or cell culture system of norovirus infection. We recently reported the discovery of the first murine norovirus, murine norovirus 1 (MNV-1), and its cultivation in macrophages and dendritic cells in vitro. We further defined interferon receptors and the STAT-1 molecule as critical in both resistance to MNV-1-induced disease in vivo and control of virus growth in vitro. To date, neither histopathological changes upon infection nor viral replication in wild-type mice has been shown. Here we extend our studies to demonstrate that MNV-1 replicates and rapidly disseminates to various tissues in immunocompetent mice and that infection is restricted by STAT1-dependent interferon responses at the levels of viral replication and virus dissemination. Infection of wild-type mice is associated with histopathological alterations in the intestine (mild inflammation) and the spleen (red pulp hypertrophy and white pulp activation); viral dissemination to the spleen, liver, lung, and lymph nodes; and low-level persistent infection in the spleen. STAT-1 inhibits viral replication in the intestine, prevents virus-induced apoptosis of intestinal cells and splenocytes, and limits viral dissemination to peripheral tissues. These findings demonstrate that murine norovirus infection of wild-type mice is associated with initial enteric seeding and subsequent extraintestinal spread, and they provide mechanistic evidence of the role of STAT-1 in controlling clinical norovirus-induced disease. PMID:17229692

  3. Regulation of human norovirus VPg nucleotidylylation by ProPol and nucleoside triphosphate binding by its amino terminal sequence in vitro.

    PubMed

    Medvedev, Alexei; Viswanathan, Prasanth; May, Jared; Korba, Brent

    2017-03-01

    The VPg protein of human Norovirus (hNoV) is a multi-functional protein essential for virus replication. The un-cleaved viral precursor protein, ProPol (NS5-6) was 100-fold more efficient in catalyzing VPg nucleotidylylation than the mature polymerase (Pol, NS6), suggesting a specific intracellular role for ProPol. Sequential and single-point alanine substitutions revealed that several positively charged amino acids in the N-terminal region of VPg regulate its nucleotidylylation by ProPol. We provide evidence that VPg directly binds NTPs, inhibition of binding inhibits nucleotidylylation, and NTP binding appears to involve the first 13 amino acids of the protein. Substitution of multiple positively charged amino acids within the first 12 amino acids of the N-terminal region inhibits nucleotidylylation without affecting binding. Substitution of only Lys20 abolishes nucleotidylylation, but not NTP binding. These studies indicate that positively charged amino acids in the first 20 amino acids of hNoV VPg regulate its nucleotidylylation though several potential mechanisms.

  4. Full-Genomic Analysis of a Human Norovirus Recombinant GII.12/13 Novel Strain Isolated from South Korea

    PubMed Central

    Han, Sang-ha; Cho, Han-Gil; Kang, Lae-Hyung; Lee, Sung-Geun; Ryu, Sang-Ryeol; Paik, Soon-Young

    2013-01-01

    Norovirus (NoV) genogroups I and II are frequently recognized as the main causes of acute gastroenteritis and outbreaks of non-bacterial foodborne diseases. Furthermore, variants and recombinant strains of this virus are continuously emerging worldwide. The aim of this study was to identify NoV strains and to investigate and characterize rare genotypes. Stool samples (n = 500) were collected from patients with symptoms of acute gastroenteritis in Korea between December 2004 and November 2007. For analysis of the samples, rapid genotype screening was performed using reverse transcriptase-polymerase chain reaction. Full sequencing, using a newly designed set of 12 primers, revealed GII-12/13 strain. The partial sequence of GII-12/13 strain was compared with published NoV (GII-1 - 14) sequences targeting RdRp and capsid regions using phylogenetic analysis with the SimPlot program, which could evaluate recombination breakpoints. SimPlot analysis was also performed with the strain GII-12/Gifu-96/JPN (AB045603) for the RdRp region and with GII-13/G5175B-83/AUS(DQ379714) for the capsid region. NoV was detected in 19 of the 500 stool samples (3.8%). Genogroup GII-4 was found most frequently (n = 9, 1.8%), followed by GII-3 (n = 4, 0.8%), GII-6 (n = 3, 0.6%), GI-6 (n = 2, 0.4%), and GII-12/13 (n = 1, 0.2%). Importantly, we identified a novel NoV recombinant strain, C9-439 (KF289337), indicating potential risks, which suggested that, recombination occurred in the region between open reading frames 1 and 2 of the GII-12/13 strain and that breakpoints occurred in the polymerase region. PMID:24391985

  5. Semi-direct lysis of swabs and evaluation of their efficiencies to recover human noroviruses GI and GII from surfaces.

    PubMed

    De Keuckelaere, Ann; Stals, Ambroos; Uyttendaele, Mieke

    2014-06-01

    Enteric viruses such as noroviruses (NoVs) continue to be the cause of widespread viral outbreaks due to person-to-person transmission, contaminated food, and contaminated surfaces. In order to optimize swabbing methodology for the detection of viruses on (food) contact surfaces, three swab elution/extraction strategies were compared in part one of this study, out of which, one strategy was based on the recently launched ISO protocol (ISO/TS 15216-1) for the determination of hepatitis A virus and NoV in food using real-time RT-PCR (RT-qPCR). These three swab elution/extraction strategies were tested for the detection of GI.4 and GII.4 NoV on high-density polyethylene (HD-PE) surfaces with the use of cotton swabs. For detection of GI.4 and GII.4, the sample recovery efficiency (SRE) obtained with the direct lysis strategy (based on ISO/TS 15216-1) was significantly lower than the SRE obtained with both other strategies. The semi-direct lysis strategy was chosen to assess the SRE of two common swabs (cotton swab and polyester swab) versus the biowipe (Biomérieux, Lyon, France) on three surfaces (HD-PE, neoprene rubber (NR), and nitrile gloves (GL)). For both surfaces, HD-PE and GL, no significant differences in SREs of GI.4 and GII.4 NoVs were detected between the three different swabs. For the coarser NR, biowipes turned out to be the best option for detecting both GI.4 and GII.4 NoV.

  6. Antibodies against Lewis antigens inhibit the binding of human norovirus GII.4 virus-like particles to saliva but not to intestinal Caco-2 cells.

    PubMed

    Carmona-Vicente, Noelia; Allen, David J; Rodríguez-Díaz, Jesús; Iturriza-Gómara, Miren; Buesa, Javier

    2016-05-21

    Human noroviruses (NoVs) are the main cause of gastroenteritis worldwide. The most commonly detected NoV strains belong to the genetically diverse GII.4 genotype, with new pandemic variants emerging periodically. Despite extensive efforts, NoV investigation has been hampered by the lack of an effective in vitro cell culture system. However, NoV-derived recombinant virus-like particles (VLPs) resembling empty capsids are good surrogates for analysing NoV antigenicity and virus-ligand interactions. NoV VLPs have been reported to bind to histo-blood group antigens (HBGAs). We have analysed the ability of NoV VLPs derived from GI.1 genotype and from three GII.4 genotype variants, GII.4-1999, GII.4-2004 and GII.4-2006b, to bind to porcine gastric mucin (PGM), human saliva and differentiated human intestinal Caco-2 cells (D-Caco-2 cells). Distinct patterns of saliva binding with the NoV GII.4 variant VLPs were observed, although they bound to D-Caco-2 cells independently of the expression of HBGAs. Monoclonal antibodies against Lewis antigens were able to block the binding of NoV VLPs to saliva, but not to D-Caco-2 cells. Blocking HBGAs on the surface of D-Caco-2 cells with specific monoclonal antibodies did not affect NoV VLP binding to cellular membranes. Co-localisation of Lewis y (Le(y)) and H-type 2 antigens with NoV VLPs was not observed by immunofluorescence assays. Although the binding of NoV VLPs of GII.4 genotype variants to human saliva samples occur with distinct HBGA binding patterns and can be blocked by antibodies against Lewis antigens, their attachment to D-Caco-2 cells can be mediated by other receptors, which still need further investigation.

  7. Comparative murine norovirus studies reveal a lack of correlation between intestinal virus titers and enteric pathology

    PubMed Central

    Kahan, Shannon M.; Liu, Guangliang; Reinhard, Mary K.; Hsu, Charlie C.; Livingston, Robert S.; Karst, Stephanie M.

    2011-01-01

    Human noroviruses are significant emerging pathogens, causing the majority of non-bacterial gastroenteritis outbreaks worldwide. The recent discovery of 30 murine norovirus strains is beginning to facilitate a detailed investigation of norovirus pathogenesis. Here, we have performed an in vivo comparative analysis of two murine norovirus strains, MNV-1 and MNV-3. In immunocompetent mice, MNV-1 caused modest intestinal pathology whereas MNV-3 was attenuated compared to MNV-1. Surprisingly though, MNV-3 reached higher titers in intestinal tissue than MNV-1. MNV-3 also displayed attenuation in mice deficient in the critical interferon signaling molecule STAT-1, demonstrating that MNV-3 attenuation is not a result of increased interferon sensitivity. Importantly, MNV-3-infected mice lost weight and developed gastric bloating and diarrhea in STAT1−/− mice, from which all animals recovered. This disease profile recapitulates several key features of acute gastroenteritis experienced by people infected with a human norovirus. PMID:22018636

  8. Detection and forecasting of oyster norovirus outbreaks: recent advances and future perspectives.

    PubMed

    Wang, Jiao; Deng, Zhiqiang

    2012-09-01

    Norovirus is a highly infectious pathogen that is commonly found in oysters growing in fecally contaminated waters. Norovirus outbreaks can cause the closure of oyster harvesting waters and acute gastroenteritis in humans associated with consumption of contaminated raw oysters. Extensive efforts and progresses have been made in detection and forecasting of oyster norovirus outbreaks over the past decades. The main objective of this paper is to provide a literature review of methods and techniques for detecting and forecasting oyster norovirus outbreaks and thereby to identify the future directions for improving the detection and forecasting of norovirus outbreaks. It is found that (1) norovirus outbreaks display strong seasonality with the outbreak peak occurring commonly in December-March in the U.S. and April-May in the Europe; (2) norovirus outbreaks are affected by multiple environmental factors, including but not limited to precipitation, temperature, solar radiation, wind, and salinity; (3) various modeling approaches may be employed to forecast norovirus outbreaks, including Bayesian models, regression models, Artificial Neural Networks, and process-based models; and (4) diverse techniques are available for near real-time detection of norovirus outbreaks, including multiplex PCR, seminested PCR, real-time PCR, quantitative PCR, and satellite remote sensing. The findings are important to the management of oyster growing waters and to future investigations into norovirus outbreaks. It is recommended that a combined approach of sensor-assisted real time monitoring and modeling-based forecasting should be utilized for an efficient and effective detection and forecasting of norovirus outbreaks caused by consumption of contaminated oysters. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Infection with the Persistent Murine Norovirus Strain MNV-S99 Suppresses IFN-Beta Release and Activation of Stat1 In Vitro.

    PubMed

    Niendorf, Sandra; Klemm, Uwe; Mas Marques, Andreas; Bock, C-Thomas; Höhne, Marina

    2016-01-01

    Norovirus infection is the main cause of epidemic non-bacterial gastroenteritis in humans. Although human norovirus (HuNoV) infection is self-limiting, it can persist for extended periods of time in immune deficient patients. Due to the lack of robust cell culture and small animal systems, little is known about HuNoV pathogenicity. However, murine norovirus (MNV) can be propagated in cell culture and is used as a model to study norovirus infection. Several MNV are known to persist in mice. In this study, we show that the MNV strain MNV-S99 persists in wild type inbred (C57BL/6J) mice over a period of at least 5 weeks post infection. Viral RNA was detectable in the jejunum, ileum, cecum, and colon, with the highest titers in the colon and cecum. To characterize the effect of MNV-S99 on the innate immune response, Stat1 phosphorylation and IFN-β production were analyzed and compared to the non-persistent strain MNV-1.CW3. While MNV-S99 and MNV-1.CW3 showed comparable growth characteristics in vitro, Stat1 phosphorylation and IFN-β release is strongly decreased after infection with MNV-S99 compared to MNV-1.CW3. In conclusion, our results show that unlike MNV-1.CW3, MNV-S99 establishes a persistent infection in mice, possibly due to interfering with the innate immune response.

  10. Phylogenetic Analyses Suggest that Factors Other Than the Capsid Protein Play a Role in the Epidemic Potential of GII.2 Norovirus

    PubMed Central

    Tohma, Kentaro; Lepore, Cara J.; Ford-Siltz, Lauren A.

    2017-01-01

    ABSTRACT Norovirus is the leading cause of acute gastroenteritis worldwide. For over two decades, a single genotype (GII.4) has been responsible for most norovirus-associated cases. However, during the winter of 2014 to 2015, the GII.4 strains were displaced by a rarely detected genotype (GII.17) in several countries of the Asian continent. Moreover, during the winter of 2016 to 2017, the GII.2 strain reemerged as predominant in different countries worldwide. This reemerging GII.2 strain is a recombinant virus that presents a GII.P16 polymerase genotype. In this study, we investigated the evolutionary dynamics of GII.2 to determine the mechanism of this sudden emergence in the human population. The phylogenetic analyses indicated strong linear evolution of the VP1-encoding sequence, albeit with minor changes in the amino acid sequence over time. Without major genetic differences among the strains, a clustering based on the polymerase genotype was observed in the tree. This association did not affect the substitution rate of the VP1. Phylogenetic analyses of the polymerase region showed that reemerging GII.P16-GII.2 strains diverged into a new cluster, with a small number of amino acid substitutions detected on the surface of the associated polymerase. Thus, besides recombination or antigenic shift, point mutations in nonstructural proteins could also lead to novel properties with epidemic potential in different norovirus genotypes. IMPORTANCE Noroviruses are a major cause of gastroenteritis worldwide. Currently, there is no vaccine or specific antiviral available to treat norovirus disease. Multiple norovirus strains infect humans, but a single genotype (GII.4) has been regarded as the most important cause of viral gastroenteritis outbreaks worldwide. Its persistence and predominance have been explained by the continuous replacement of variants that present new antigenic properties on their capsid protein, thus evading the herd immunity acquired to the previous

  11. Phylogenetic Analyses Suggest that Factors Other Than the Capsid Protein Play a Role in the Epidemic Potential of GII.2 Norovirus.

    PubMed

    Tohma, Kentaro; Lepore, Cara J; Ford-Siltz, Lauren A; Parra, Gabriel I

    2017-01-01

    Norovirus is the leading cause of acute gastroenteritis worldwide. For over two decades, a single genotype (GII.4) has been responsible for most norovirus-associated cases. However, during the winter of 2014 to 2015, the GII.4 strains were displaced by a rarely detected genotype (GII.17) in several countries of the Asian continent. Moreover, during the winter of 2016 to 2017, the GII.2 strain reemerged as predominant in different countries worldwide. This reemerging GII.2 strain is a recombinant virus that presents a GII.P16 polymerase genotype. In this study, we investigated the evolutionary dynamics of GII.2 to determine the mechanism of this sudden emergence in the human population. The phylogenetic analyses indicated strong linear evolution of the VP1-encoding sequence, albeit with minor changes in the amino acid sequence over time. Without major genetic differences among the strains, a clustering based on the polymerase genotype was observed in the tree. This association did not affect the substitution rate of the VP1. Phylogenetic analyses of the polymerase region showed that reemerging GII.P16-GII.2 strains diverged into a new cluster, with a small number of amino acid substitutions detected on the surface of the associated polymerase. Thus, besides recombination or antigenic shift, point mutations in nonstructural proteins could also lead to novel properties with epidemic potential in different norovirus genotypes. IMPORTANCE Noroviruses are a major cause of gastroenteritis worldwide. Currently, there is no vaccine or specific antiviral available to treat norovirus disease. Multiple norovirus strains infect humans, but a single genotype (GII.4) has been regarded as the most important cause of viral gastroenteritis outbreaks worldwide. Its persistence and predominance have been explained by the continuous replacement of variants that present new antigenic properties on their capsid protein, thus evading the herd immunity acquired to the previous variants

  12. Inhibition of norovirus replication by morpholino oligomers targeting the 5′-end of the genome

    PubMed Central

    Bok, Karin; Cavanaugh, Victoria J.; Matson, David O.; González-Molleda, Lorenzo; Chang, Kyeong-Ok; Zintz, Carmelann; Smith, Alvin W.; Iversen, Patrick; Green, Kim Y.; Campbell, Ann E.

    2013-01-01

    Noroviruses are an important cause of non-bacterial epidemic gastroenteritis, but no specific antiviral therapies are available. We investigated the inhibitory effect of phosphorodiamidiate morpholino oligomers (PMOs) targeted against norovirus sequences. A panel of peptide-conjugated PMOs (PPMOs) specific for the murine norovirus (MNV) genome was developed, and two PPMO compounds directed against the first AUG of the ORF1 coding sequence near the 5′-end of the genome proved effective in inhibiting MNV replication in cells. A consensus PPMO (designated Noro 1.1), designed to target the corresponding region of several diverse human norovirus genotypes, decreased the efficiency of protein translation in a cell-free luciferase reporter assay and inhibited Norwalk virus protein expression in replicon-bearing cells. Our data suggest that PPMOs directed against the relatively conserved 5′-end of the norovirus genome may show broad antiviral activity against this genetically diverse group of viruses. PMID:18783811

  13. Quantification of human responses

    NASA Technical Reports Server (NTRS)

    Steinlage, R. C.; Gantner, T. E.; Lim, P. Y. W.

    1992-01-01

    Human perception is a complex phenomenon which is difficult to quantify with instruments. For this reason, large panels of people are often used to elicit and aggregate subjective judgments. Print quality, taste, smell, sound quality of a stereo system, softness, and grading Olympic divers and skaters are some examples of situations where subjective measurements or judgments are paramount. We usually express what is in our mind through language as a medium but languages are limited in available choices of vocabularies, and as a result, our verbalizations are only approximate expressions of what we really have in mind. For lack of better methods to quantify subjective judgments, it is customary to set up a numerical scale such as 1, 2, 3, 4, 5 or 1, 2, 3, ..., 9, 10 for characterizing human responses and subjective judgments with no valid justification except that these scales are easy to understand and convenient to use. But these numerical scales are arbitrary simplifications of the complex human mind; the human mind is not restricted to such simple numerical variations. In fact, human responses and subjective judgments are psychophysical phenomena that are fuzzy entities and therefore difficult to handle by conventional mathematics and probability theory. The fuzzy mathematical approach provides a more realistic insight into understanding and quantifying human responses. This paper presents a method for quantifying human responses and subjective judgments without assuming a pattern of linear or numerical variation for human responses. In particular, quantification and evaluation of linguistic judgments was investigated.

  14. Characterization of a Novel Conformational GII.4 Norovirus Epitope: Implications for Norovirus-Host Interactions

    PubMed Central

    Carmona-Vicente, Noelia; Vila-Vicent, Susana; Allen, David; Gozalbo-Rovira, Roberto; Iturriza-Gómara, Miren

    2016-01-01

    ABSTRACT Human noroviruses (NoVs) are the main etiological agents of acute gastroenteritis worldwide. While NoVs are highly diverse (more than 30 genotypes have been detected in humans), during the last 40 years most outbreaks and epidemics have been caused by GII.4 genotype strains, raising questions about their persistence in the population. Among other potential explanations, immune evasion is considered to be a main driver of their success. In order to study antibody recognition and evasion in detail, we analyzed a conformational epitope recognized by a monoclonal antibody (3C3G3) by phage display, site-directed mutagenesis, and surface plasmon resonance. Our results show that the predicted epitope is composed of 11 amino acids within the P domain: P245, E247, I389, Q390, R397, R435, G443, Y444, P445, N446, and D448. Only two of them, R397 and D448, differ from the homologous variant (GII.4 Den-Haag_2006b) and from a previous variant (GII.4 VA387_1996) that is not recognized by the antibody. A double mutant derived from the VA387_1996 variant containing both changes, Q396R and N447D, is recognized by the 3C3G3 monoclonal antibody, confirming the participation of the two sites in the epitope recognized by the antibody. Furthermore, a single change, Q396R, is able to modify the histo-blood group antigen (HBGA) recognition pattern. These results provide evidence that the epitope recognized by the 3C3G3 antibody is involved in the virus-host interactions, both at the immunological and at the receptor levels. IMPORTANCE Human noroviruses are the main cause of viral diarrhea worldwide in people of all ages. Noroviruses can infect individuals who had been previously exposed to the same or different norovirus genotypes. Norovirus genotype GII.4 has been reported to be most prevalent during the last 40 years. In the present study, we describe a novel viral epitope identified by a monoclonal antibody and located within the highly diverse P domain of the capsid protein

  15. Viability and heat resistance of murine norovirus on bread.

    PubMed

    Takahashi, Michiko; Takahashi, Hajime; Kuda, Takashi; Kimura, Bon

    2016-01-04

    Contaminated bread was the cause of a large-scale outbreak of norovirus disease in Japan in 2014. Contamination of seafood and uncooked food products by norovirus has been reported several times in the past; however the outbreak resulting from the contamination of bread products was unusual. A few reports on the presence of norovirus on bread products are available; however there have been no studies on the viability and heat resistance of norovirus on breads, which were investigated in this study. ce:italic>/ce:italic> strain 1 (MNV-1), a surrogate for human norovirus, was inoculated directly on 3 types of bread, but the infectivity of MNV-1 on bread samples was almost unchanged after 5days at 20°C. MNV-1 was inoculated on white bread that was subsequently heated in a toaster for a maximum of 2min. The results showed that MNV-1 remained viable if the heating period was insufficient to inactivate. In addition, bread dough contaminated with MNV-1 was baked in the oven. Our results indicated that MNV-1 may remain viable on breads if the heating duration or temperature is insufficient. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Detection of human norovirus in cherry tomatoes, blueberries and vegetable salad by using a receptor-binding capture and magnetic sequestration (RBCMS) method.

    PubMed

    Pan, Liangwen; Zhang, Qigang; Li, Xiang; Tian, Peng

    2012-06-01

    In this study, we developed a sensitive receptor-binding capture and magnetic sequestration (RBCMS) method capable of concentrating human norovirus (HuNoV) from various food samples within few hours. We found that distilled water was suitable for the elution of HuNoV from inoculated tomatoes and blueberries, and glycine buffer improved the elution of HuNoV from inoculated salad. A significant improvement in post-extraction RNA yield was achieved by sequentially heat-releasing and column-extracting over either technique alone. The viral recovery of the RBCMS method was significantly higher than both the same-day PEG method (90 min PEG precipitation) and the two-day PEG method (overnight PEG precipitation) with a recovery rate of 8.75%, 1.03% and 5.40%, respectively. The detection limit of HuNoV by RBCMS method was significantly improved to 0.056 RTU. The estimated minimal concentration powers (MCPs) were 6.11, 30.48, and 63.60-fold for the same-day PEG, two-day PEG, and RBCMS methods, respectively. RNase protection assay suggests that the viral genome was protected from RNase attack by remaining within the viral capsid. The signal detected by the RBCMS method might be more biologically relevant, as it requires both intact viral capsid to bind to HBGA receptors and the presence of viral genome to be amplified. Overall, the RBCMS method takes significantly less time than current PEG precipitation methods, recovers a higher yield of HuNoV from various food samples, and hence exhibits higher sensitivity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. The influence of temperature, pH, and water immersion on the high hydrostatic pressure inactivation of GI.1 and GII.4 human noroviruses.

    PubMed

    Li, Xinhui; Chen, Haiqiang; Kingsley, David H

    2013-10-15

    Detection of human norovirus (HuNoV) usually relies on molecular biology techniques, such as qRT-PCR. Since histo-blood group antigens (HBGAs) are the functional receptors for HuNoV, HuNoV can bind to porcine gastric mucin (PGM), which contains HBGA-like antigens. In this study, PGM-conjugated magnetic beads were used to collect and quantify potentially infectious HuNoV strains GI.1 and GII.4 treated by high hydrostatic pressure (HHP). Both GI.1 and GII.4 strains used in this study showed increasing pressure sensitivity as judged by loss of PGM binding with decreasing temperature over a range of 1 to 35 °C. Both GI.1 and GII.4 were more resistant to pressure at pH4 than at neutral pH. Because GI.1 was significantly more resistant to pressure than GII.4, it was used to evaluate HuNoV pressure inactivation in blueberries. GI.1 on dry blueberries was very resistant to pressure while immersion of blueberries in water during pressure treatments substantially enhanced the inactivation. For example, a 2 min-600 MPa treatment of dry blueberries at 1 and 21 °C resulted in <1-log reductions while a 2.7-log reduction of GI.1 was achieved by a treatment at 500 MPa for 2 min at 1 °C when blueberries were immersed in water. In total, this novel study provides unique information for designing pressure processing parameters (pressure, temperature, and time) and product formulations (such as pH) to inactivate HuNoV in high-risk foods such as berries.

  18. Detection of human Norovirus in cherry tomatoes, blueberries and vegetable salad by using a receptor binding based capture and magnetic sequestration(RBCMS) method

    USDA-ARS?s Scientific Manuscript database

    Contaminated produce related norovirus (NoV) outbreak is a major public health concern. The establishment of a simple assay for concentrating and detecting NoV contamination in fresh produce that can be performed in a single day would be of great benefit to the producers and regulators of produce pr...

  19. Modeling and Prediction of Oyster Norovirus Outbreaks along Gulf of Mexico Coast.

    PubMed

    Wang, Jiao; Deng, Zhiqiang

    2016-05-01

    Oyster norovirus outbreaks often pose high risks to human health. However, little is known about environmental factors controlling the outbreaks, and little can be done to prevent the outbreaks because they are generally considered to be unpredictable. We sought to develop a mathematical model for predicting risks of oyster norovirus outbreaks using environmental predictors. We developed a novel probability-based Artificial Neural Network model, called NORF model, using 21 years of environmental and norovirus outbreak data collected from Louisiana oyster harvesting areas along the Gulf of Mexico coast, USA. The NORF model involves six input variables that were selected through stepwise regression analysis and sensitivity analysis. We found that the model-based probability of norovirus outbreaks was most sensitive to gage height (the depth of water in an oyster bed) and water temperature, followed by wind, rainfall, and salinity, respectively. The NORF model predicted all historical oyster norovirus outbreaks from 1994 through 2014. Specifically, norovirus outbreaks occurred when the NORF model probability estimate was > 0.6, whereas no outbreaks occurred when the estimated probability was < 0.5. Outbreaks may also occur when the estimated probability is 0.5-0.6. Our findings require further confirmation, but they suggest that oyster norovirus outbreaks may be predictable using the NORF model. The ability to predict oyster norovirus outbreaks at their onset may make it possible to prevent or at least reduce the risk of norovirus outbreaks by closing potentially affected oyster beds. Wang J, Deng Z. 2016. Modeling and prediction of oyster norovirus outbreaks along Gulf of Mexico coast. Environ Health Perspect 124:627-633; http://dx.doi.org/10.1289/ehp.1509764.

  20. Modeling and Prediction of Oyster Norovirus Outbreaks along Gulf of Mexico Coast

    PubMed Central

    Wang, Jiao; Deng, Zhiqiang

    2015-01-01

    Background: Oyster norovirus outbreaks often pose high risks to human health. However, little is known about environmental factors controlling the outbreaks, and little can be done to prevent the outbreaks because they are generally considered to be unpredictable. Objective: We sought to develop a mathematical model for predicting risks of oyster norovirus outbreaks using environmental predictors. Methods: We developed a novel probability-based Artificial Neural Network model, called NORF model, using 21 years of environmental and norovirus outbreak data collected from Louisiana oyster harvesting areas along the Gulf of Mexico coast, USA. The NORF model involves six input variables that were selected through stepwise regression analysis and sensitivity analysis. Results: We found that the model-based probability of norovirus outbreaks was most sensitive to gage height (the depth of water in an oyster bed) and water temperature, followed by wind, rainfall, and salinity, respectively. The NORF model predicted all historical oyster norovirus outbreaks from 1994 through 2014. Specifically, norovirus outbreaks occurred when the NORF model probability estimate was > 0.6, whereas no outbreaks occurred when the estimated probability was < 0.5. Outbreaks may also occur when the estimated probability is 0.5–0.6. Conclusions: Our findings require further confirmation, but they suggest that oyster norovirus outbreaks may be predictable using the NORF model. The ability to predict oyster norovirus outbreaks at their onset may make it possible to prevent or at least reduce the risk of norovirus outbreaks by closing potentially affected oyster beds. Citation: Wang J, Deng Z. 2016. Modeling and prediction of oyster norovirus outbreaks along Gulf of Mexico coast. Environ Health Perspect 124:627–633; http://dx.doi.org/10.1289/ehp.1509764 PMID:26528621

  1. CDC Vital Signs: Preventing Norovirus Outbreaks

    MedlinePlus

    ... norovirus to others through close contact or by contaminating food and surfaces. Food service workers who have ... evaluation of outbreaks, including the National Outbreak Reporting System, National Voluntary Environmental Assessment Information System, Norovirus Sentinel ...

  2. High pressure processing's potential to inactivate norovirus and other fooodborne viruses

    USDA-ARS?s Scientific Manuscript database

    High pressure processing (HPP) can inactivate human norovirus. However, all viruses are not equally susceptible to HPP. Pressure treatment parameters such as required pressure levels, initial pressurization temperatures, and pressurization times substantially affect inactivation. How food matrix ...

  3. Novel norovirus in dogs with diarrhea.

    PubMed

    Mesquita, João Rodrigo; Barclay, Leslie; Nascimento, Maria São José; Vinjé, Jan

    2010-06-01

    To identify the prevalence and genetic variability of noroviruses in dogs, we tested fecal samples by using reverse transcription-PCR. We found canine norovirus in 40% and 9% of dogs with and without diarrhea, respectively. The virus was genetically unrelated to other noroviruses and constitutes a tentative new genogroup.

  4. Waterborne norovirus outbreak during a summer excursion in Northern Italy.

    PubMed

    Di Bartolo, Ilaria; Pavoni, Enrico; Tofani, Silvia; Consoli, Marta; Galuppini, Elisa; Losio, Marina Nadia; Ruggeri, Franco Maria; Varisco, Giorgio

    2015-01-01

    In September 2011, an acute gastroenteritis outbreak affected 33 children in Northern Italy. Patients had drunk river water during an excursion. Identical GI.4 norovirus genomes were detected from one patient's stools and from the river water. Improper discharge of human sewage into the river may have caused this waterborne outbreak.

  5. High hydrostatic pressure processing of murine norovirus 1-contaminated oysters inhibits oral infection in STAT-1 -/- deficient female mice

    USDA-ARS?s Scientific Manuscript database

    We have previously demonstrated that high pressure processing (HPP) is effective in preventing in vitro replication of murine norovirus strain 1 (MNV-1), a human norovirus surrogate, in a monocyte cell line following extraction from MNV-1-contaminated oysters. In the present study, the efficacy of ...

  6. Evidence for asymptomatic norovirus infection transmission associated with swimming at a tropical beach

    EPA Science Inventory

    Swimming in fecally-contaminated natural waterbodies can result in gastrointestinal (GI) infections and associated symptoms. However, the pathogenic microorganisms responsible are often unidentified because studies nearly always rely on self-reported symptoms. Noroviruses have be...

  7. Evidence for asymptomatic norovirus infection transmission associated with swimming at a tropical beach

    EPA Science Inventory

    Swimming in fecally-contaminated natural waterbodies can result in gastrointestinal (GI) infections and associated symptoms. However, the pathogenic microorganisms responsible are often unidentified because studies nearly always rely on self-reported symptoms. Noroviruses have be...

  8. Physical removal and transfer of murine norovirus and hepatitis A virus from contaminated produce by scrubbing and peeling.

    PubMed

    Wang, Qing; Erickson, Marilyn C; Ortega, Ynes; Cannon, Jennifer L

    2013-01-01

    Human noroviruses and hepatitis A virus are responsible for numerous outbreaks associated with handling fresh produce. In this study, physical removal of hepatitis A virus and murine norovirus, a human norovirus surrogate, from contaminated produce items (honeydew melons, cantaloupes, carrots, and celery) by scrubbing under running water with a nylon brush or scouring pad and by peeling (carrots and celery) with a peeler was investigated. The degree and extent of utensil contamination with viruses during these operations in the presence and absence of food residue also was investigated. Scrubbing or peeling produce initially inoculated with ∼5.5 log PFU of each virus resulted in significant levels of virus removal, ranging from 0.93 to 2.85 log PFU. However, utensil cross-contamination occurred, with >2 log PFU of virus transferred from a single produce item. After preparation of a contaminated produce item, utensil cross-contamination resulted in virus detection on seven successively prepared produce items. Produce residue accumulation on utensils variably impacted virus transfer to utensil surfaces. Results indicate that scrubbing and peeling produce can reduce levels of viruses on contaminated produce, but the importance of utensil sanitation to prevent cross-contamination is highlighted. Findings also provide important information for modeling virus cross-contamination during food preparation.

  9. Impact of genotype-specific herd immunity on the circulatory dynamism of norovirus: a 10-year longitudinal study of viral acute gastroenteritis.

    PubMed

    Sakon, Naomi; Yamazaki, Kenji; Nakata, Keiko; Kanbayashi, Daiki; Yoda, Tomoko; Mantani, Masanobu; Kase, Tetsuo; Takahashi, Kazuo; Komano, Jun

    2015-03-15

    Human norovirus is a major cause of viral acute gastroenteritis worldwide. However, the transition of endemic norovirus genotypes remains poorly understood. The characteristics of natural immunity against norovirus are unclear because few studies have been performed in the natural infection setting. This prospective 10-year surveillance study of acute gastroenteritis in the province of Osaka, Japan, revealed that norovirus spread shows temporal, geographic, and age group-specific features in the humans. Genogroup II genotype 4 (GII.4) was detected in most sporadic pediatric cases, as well as in foodborne and nursing home outbreaks, respectively. The dominant genotypes in outbreaks at childcare facilities and schools shifted every season and involved GI, GII.2, GII.3, GII.4, and GII.6. Evidence at both the facility and individual levels indicated that genotype-specific herd immunity lasted long enough to influence the endemic norovirus genotype in the next season. Thus, norovirus circulates through human populations in a uniquely dynamic fashion.

  10. Norovirus Capture with Histo-Blood Group Antigens Reveals Novel Virus-Ligand Interactions

    PubMed Central

    Harrington, Patrick R.; Vinjé, Jan; Moe, Christine L.; Baric, Ralph S.

    2004-01-01

    Noroviruses are genetically diverse, uncultivable, positive-sense RNA viruses and are the most common cause of epidemic acute gastroenteritis in humans in the United States. Recent studies of norovirus attachment in vitro by using recombinant virus-like particles (VLPs) suggest that various norovirus strains exhibit different patterns of attachment to ABH histo-blood group antigens, which are carbohydrate epitopes present in high concentrations on mucosal cell surfaces of the gut. However, attachment of live norovirus strains to histo-blood group antigens has not been investigated to date. Utilizing a newly designed magnetic bead-virus capture method, we characterized histo-blood group antigen attachment properties of various norovirus strains obtained from clinical stool specimens to compare the attachment properties of wild-type virus and VLPs and to further map norovirus attachment. Consistent with previous reports using VLPs, various strains of noroviruses exhibited different patterns of attachment to histo- blood group antigens. Norwalk virus bound specifically to H type 1, H type 3, and Leb. Two genogroup II noroviruses, one representing the Toronto genotype and the other from a novel genotype, bound specifically to Leb. A Desert Shield-like strain did not attach to H types 1, 2, or 3, H type 1 and 3 precursors, Lea, or Leb. Surprisingly, wild-type Snow Mountain virus (SMV) attached specifically to H type 3, which contradicted previous findings with SMV VLPs. On further investigation, we found that stool components promote this attachment, providing the first known observation that one or more components of human feces could promote and enhance norovirus attachment to histo-blood group antigens. PMID:14990722

  11. [Chronic norovirus infection in an immunocompromised patient].

    PubMed

    Lambregts, Merel M C; Alleman, Maarten A; Ruys, Gijs J H M; Groeneveld, Paul H P

    2010-01-01

    A 68-year-old man, immunocompromised due to non-Hodgkin lymphoma and chemotherapy, was admitted for a community-acquired norovirus infection. He developed chronic intermittent diarrhoea and cachexia. A video-capsule examination showed severe mucosal atrophy in the jejunum. The patient died eight months after the initial norovirus infection. Eight of the nine stool examinations were positive for the norovirus during this entire period. Excretion of norovirus is known to persist after the symptoms have been resolved. However, there is only one previously reported case of excretion over such a long period. Recognising a chronic norovirus infection in immunocompromised patients is vital as then complications such as mucosal atrophy with malabsorption and cachexia can be diagnosed and supportive therapy can be started. Furthermore, recognising a chronic norovirus infection is essential for preventing norovirus outbreaks. Infected patients should always be isolated, regardless of their symptoms and faecal viral load.

  12. Static and Evolving Norovirus Genotypes: Implications for Epidemiology and Immunity.

    PubMed

    Parra, Gabriel I; Squires, R Burke; Karangwa, Consolee K; Johnson, Jordan A; Lepore, Cara J; Sosnovtsev, Stanislav V; Green, Kim Y

    2017-01-01

    Noroviruses are major pathogens associated with acute gastroenteritis worldwide. Their RNA genomes are diverse, with two major genogroups (GI and GII) comprised of at least 28 genotypes associated with human disease. To elucidate mechanisms underlying norovirus diversity and evolution, we used a large-scale genomics approach to analyze human norovirus sequences. Comparison of over 2000 nearly full-length ORF2 sequences representing most of the known GI and GII genotypes infecting humans showed a limited number (≤5) of distinct intra-genotypic variants within each genotype, with the exception of GII.4. The non-GII.4 genotypes were comprised of one or more intra-genotypic variants, with each variant containing strains that differed by only a few residues over several decades (remaining "static") and that have co-circulated with no clear epidemiologic pattern. In contrast, the GII.4 genotype presented the largest number of variants (>10) that have evolved over time with a clear pattern of periodic variant replacement. To expand our understanding of these two patterns of diversification ("static" versus "evolving"), we analyzed using NGS the nearly full-length norovirus genome in healthy individuals infected with GII.4, GII.6 or GII.17 viruses in different outbreak settings. The GII.4 viruses accumulated mutations rapidly within and between hosts, while the GII.6 and GII.17 viruses remained relatively stable, consistent with their diversification patterns. Further analysis of genetic relationships and natural history patterns identified groupings of certain genotypes into larger related clusters designated here as "immunotypes". We propose that "immunotypes" and their evolutionary patterns influence the prevalence of a particular norovirus genotype in the human population.

  13. Static and Evolving Norovirus Genotypes: Implications for Epidemiology and Immunity

    PubMed Central

    Karangwa, Consolee K.; Sosnovtsev, Stanislav V.

    2017-01-01

    Noroviruses are major pathogens associated with acute gastroenteritis worldwide. Their RNA genomes are diverse, with two major genogroups (GI and GII) comprised of at least 28 genotypes associated with human disease. To elucidate mechanisms underlying norovirus diversity and evolution, we used a large-scale genomics approach to analyze human norovirus sequences. Comparison of over 2000 nearly full-length ORF2 sequences representing most of the known GI and GII genotypes infecting humans showed a limited number (≤5) of distinct intra-genotypic variants within each genotype, with the exception of GII.4. The non-GII.4 genotypes were comprised of one or more intra-genotypic variants, with each variant containing strains that differed by only a few residues over several decades (remaining “static”) and that have co-circulated with no clear epidemiologic pattern. In contrast, the GII.4 genotype presented the largest number of variants (>10) that have evolved over time with a clear pattern of periodic variant replacement. To expand our understanding of these two patterns of diversification (“static” versus “evolving”), we analyzed using NGS the nearly full-length norovirus genome in healthy individuals infected with GII.4, GII.6 or GII.17 viruses in different outbreak settings. The GII.4 viruses accumulated mutations rapidly within and between hosts, while the GII.6 and GII.17 viruses remained relatively stable, consistent with their diversification patterns. Further analysis of genetic relationships and natural history patterns identified groupings of certain genotypes into larger related clusters designated here as “immunotypes”. We propose that “immunotypes” and their evolutionary patterns influence the prevalence of a particular norovirus genotype in the human population. PMID:28103318

  14. Norovirus Surveillance: An Epidemiological Perspective.

    PubMed

    Harris, John P

    2016-02-01

    Surveillance for norovirus is challenging because the nature of illness due to norovirus is such that the majority of people who are infected will not have any contact with medical services and are highly unlikely to have a sample collected for diagnosis. Public health advice urges people to not visit hospitals or their family physicians, to prevent the risk further spread. The recognition of the importance of this pathogen was quickly established following the introduction of surveillance of outbreaks of gastrointestinal infection in England and Wales in 1992. This period saw >1800 outbreaks of norovirus infection reported in hospitals in England, affecting >45 000 patients and staff. A new system for reporting outbreaks of norovirus infection in hospitals, the Hospital Norovirus outbreak Reporting Scheme (HNORS), began in January 2009. Summary information on outbreaks is provided by infection control staff at hospitals and includes questions on the date the first and last person in the outbreak became symptomatic and whether closure of a bay or ward was needed. In the first 3 years (2009-2011) of the HNORS surveillance scheme, 4000 outbreaks were reported, affecting 40 000 patients and 10 000 staff. Over the last 3 years, these outbreaks have been associated with an average of 13 000 patients and 3400 staff becoming ill, with 15 000 lost bed-days annually. With the possible introduction of a vaccine on the horizon, targeted research with a more integrated approach to laboratory testing and outbreak reporting is essential to a greater understanding of the epidemiology of norovirus. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  15. Evidence-Based interventions of Norovirus outbreaks in China.

    PubMed

    Chen, Tianmu; Gu, Haogao; Leung, Ross Ka-Kit; Liu, Ruchun; Chen, Qiuping; Wu, Ying; Li, Yaman

    2016-10-12

    In resource-limited settings where laboratory capacity is limited and response strategy is non-specific, delayed or inappropriate intervention against outbreaks of Norovirus (NoV) are common. Here we report interventions of two norovirus outbreaks, which highlight the importance of evidence-based modeling and assessment to identify infection sources and formulate effective response strategies. Spatiotemporal scanning, mathematical and random walk modeling predicted the modes of transmission in the two incidents, which were supported by laboratory results and intervention outcomes. Simulation results indicated that contaminated water was 14 to 500 fold more infectious than infected individuals. Asymptomatic individuals were not effective transmitters. School closure for up to a week still could not contain the outbreak unless the duration was extended to 10 or more days. The total attack rates (TARs) for waterborne NoV outbreaks reported in China (n = 3, median = 4.37) were significantly (p < 0.05) lower than worldwide (n = 14, median = 41.34). The low TARs are likely due to the high number of the affected population. We found that school closure alone could not contain Norovirus outbreaks. Overlooked personal hygiene may serve as a hotbed for infectious disease transmission. Our results reveal that evidence-based investigations can facilitate timely interventions of Norovirus transmission.

  16. Characterization of ozone disinfection of murine norovirus.

    PubMed

    Lim, Mi Young; Kim, Ju-Mi; Lee, Jung Eun; Ko, GwangPyo

    2010-02-01

    Despite the importance of human noroviruses (NoVs) in public health, little information concerning the effectiveness of ozone against NoVs is available. We determined the efficacy of ozone disinfection using murine norovirus (MNV) as a surrogate of human NoV. MNV in ozone demand-free buffer was exposed to a predetermined dose of ozone at two different pHs and temperatures. The virus remaining in the solution was analyzed by plaque assay, real-time TaqMan reverse transcriptase PCR (RT-PCR) (short template), and long-template conventional RT-PCR. Under all conditions, more than 99% of the MNV was inactivated by ozone at 1 mg/liter within 2 min. Both RT-PCR assays significantly underestimated the inactivation of MNV, compared with that measured by plaque assay. Our results indicate that NoV may be more resistant to ozone than has been previously reported. Nevertheless, proper ozone disinfection practices can be used to easily control its transmission in water.

  17. Viability of murine norovirus in salads and dressings and its inactivation using heat-denatured lysozyme.

    PubMed

    Takahashi, Hajime; Tsuchiya, Tomoki; Takahashi, Michiko; Nakazawa, Moemi; Watanabe, Tomoka; Takeuchi, Akira; Kuda, Takashi; Kimura, Bon

    2016-09-16

    In recent years, a number of food poisoning outbreaks due to the contamination of norovirus in ready-to-eat (RTE) foods such as salads have been reported, and this issue is regarded as a global problem. The risk of contamination of fresh vegetables with norovirus has been previously reported, but the survivability of norovirus that contaminates salads remains unknown. In addition, there have been limited reports on the control of norovirus in food products by using inactivating agents. In this study, the viability of norovirus in various types of salads and dressings was examined using murine norovirus strain 1 (MNV-1) as a surrogate for the closely related human norovirus. In addition, the inactivation of MNV-1 in salads was examined using heat-denatured lysozyme, which had been reported to inactivate norovirus. MNV-1 was inoculated in 4 types of salads (coleslaw, thousand island salad, vinaigrette salad, egg salad) and 3 types of dressings (mayonnaise, thousand island dressing, vinaigrette dressing), stored at 4°C for 5days. The results revealed that in the vinaigrette dressing, the infectivity of MNV-1 decreased by 2.6logPFU/mL in 5days, whereas in the other dressings and salads, the infectivity of MNV-1 did not show any significant decrease. Next, 1% heat-denatured lysozyme was added to the 4 types of salads, and subsequently it was found that in 2 types of salads (thousand island salad, vinaigrette salad), the infectivity of MNV-1 decreased by >4.0logPFU/g, whereas in coleslaw salad, a decrease of 3.0logPFU/g was shown. However, in egg salads, the infectivity of MNV-1 did not show such decrease. These results suggest that norovirus can survive for 5days in contaminated salads. Further, these findings also indicated that heat-denatured lysozyme had an inactivating effect on norovirus, even in salads. In the future, heat-denatured lysozyme can be used as a novel norovirus-inactivating agent, although it is essential to investigate the mechanism of inactivating

  18. Inactivation of a Norovirus by High-Pressure Processing▿

    PubMed Central

    Kingsley, David H.; Holliman, Daniel R.; Calci, Kevin R.; Chen, Haiqiang; Flick, George J.

    2007-01-01

    Murine norovirus (strain MNV-1), a propagable norovirus, was evaluated for susceptibility to high-pressure processing. Experiments with virus stocks in Dulbecco's modified Eagle medium demonstrated that at room temperature (20°C) the virus was inactivated over a pressure range of 350 to 450 MPa, with a 5-min, 450-MPa treatment being sufficient to inactivate 6.85 log10 PFU of MNV-1. The inactivation of MNV-1 was enhanced when pressure was applied at an initial temperature of 5°C; a 5-min pressure treatment of 350 MPa at 30°C inactivated 1.15 log10 PFU of virus, while the same treatment at 5°C resulted in a reduction of 5.56 log10 PFU. Evaluation of virus inactivation as a function of treatment times ranging from 0 to 150 s and 0 to 900 s at 5°C and 20°C, respectively, indicated that a decreasing rate of inactivation with time was consistent with Weibull or log-logistic inactivation kinetics. The inactivation of MNV-1 directly within oyster tissues was demonstrated; a 5-min, 400-MPa treatment at 5°C was sufficient to inactivate 4.05 log10 PFU. This work is the first demonstration that norovirus can be inactivated by high pressure and suggests good prospects for inactivation of nonpropagable human norovirus strains in foods. PMID:17142353

  19. Norovirus Polymerase Fidelity Contributes to Viral Transmission In Vivo.

    PubMed

    Arias, Armando; Thorne, Lucy; Ghurburrun, Elsa; Bailey, Dalan; Goodfellow, Ian

    2016-01-01

    Intrahost genetic diversity and replication error rates are intricately linked to RNA virus pathogenesis, with alterations in viral polymerase fidelity typically leading to attenuation during infections in vivo. We have previously shown that norovirus intrahost genetic diversity also influences viral pathogenesis using the murine norovirus model, as increasing viral mutation frequency using a mutagenic nucleoside resulted in clearance of a persistent infection in mice. Given the role of replication fidelity and genetic diversity in pathogenesis, we have now investigated whether polymerase fidelity can also impact virus transmission between susceptible hosts. We have identified a high-fidelity norovirus RNA-dependent RNA polymerase mutant (I391L) which displays delayed replication kinetics in vivo but not in cell culture. The I391L polymerase mutant also exhibited lower transmission rates between susceptible hosts than the wild-type virus and, most notably, another replication defective mutant that has wild-type levels of polymerase fidelity. These results provide the first experimental evidence that norovirus polymerase fidelity contributes to virus transmission between hosts and that maintaining diversity is important for the establishment of infection. This work supports the hypothesis that the reduced polymerase fidelity of the pandemic GII.4 human norovirus isolates may contribute to their global dominance. IMPORTANCE Virus replication fidelity and hence the intrahost genetic diversity of viral populations are known to be intricately linked to viral pathogenesis and tropism as well as to immune and antiviral escape during infection. In this study, we investigated whether changes in replication fidelity can impact the ability of a virus to transmit between susceptible hosts by the use of a mouse model for norovirus. We show that a variant encoding a high-fidelity polymerase is transmitted less efficiently between mice than the wild-type strain. This constitutes

  20. Norovirus Polymerase Fidelity Contributes to Viral Transmission In Vivo

    PubMed Central

    Thorne, Lucy; Ghurburrun, Elsa

    2016-01-01

    ABSTRACT Intrahost genetic diversity and replication error rates are intricately linked to RNA virus pathogenesis, with alterations in viral polymerase fidelity typically leading to attenuation during infections in vivo. We have previously shown that norovirus intrahost genetic diversity also influences viral pathogenesis using the murine norovirus model, as increasing viral mutation frequency using a mutagenic nucleoside resulted in clearance of a persistent infection in mice. Given the role of replication fidelity and genetic diversity in pathogenesis, we have now investigated whether polymerase fidelity can also impact virus transmission between susceptible hosts. We have identified a high-fidelity norovirus RNA-dependent RNA polymerase mutant (I391L) which displays delayed replication kinetics in vivo but not in cell culture. The I391L polymerase mutant also exhibited lower transmission rates between susceptible hosts than the wild-type virus and, most notably, another replication defective mutant that has wild-type levels of polymerase fidelity. These results provide the first experimental evidence that norovirus polymerase fidelity contributes to virus transmission between hosts and that maintaining diversity is important for the establishment of infection. This work supports the hypothesis that the reduced polymerase fidelity of the pandemic GII.4 human norovirus isolates may contribute to their global dominance. IMPORTANCE Virus replication fidelity and hence the intrahost genetic diversity of viral populations are known to be intricately linked to viral pathogenesis and tropism as well as to immune and antiviral escape during infection. In this study, we investigated whether changes in replication fidelity can impact the ability of a virus to transmit between susceptible hosts by the use of a mouse model for norovirus. We show that a variant encoding a high-fidelity polymerase is transmitted less efficiently between mice than the wild-type strain. This

  1. Probing human response times

    NASA Astrophysics Data System (ADS)

    Johansen, Anders

    2004-07-01

    In a recent preprint (Dialog in e-mail traffic, preprint cond-mat/0304433), the temporal dynamics of an e-mail network has been investigated by Eckmann, Moses and Sergi. Specifically, the time period between an e-mail message and its reply were recorded. It will be shown here that their data agrees quantitatively with the frame work proposed to explain a recent experiment on the response of “internauts” to a news publication (Physica A 296(3-4) (2001) 539) despite differences in communication channels, topics, time-scale and socio-economic characteristics of the two population. This suggest a generalized response time distribution ∼ t-1 for human populations in the absence of deadlines with important implications for psychological and social studies as well the study of dynamical networks.

  2. Norovirus transmission on cruise ship.

    PubMed

    Isakbaeva, Elmira T; Widdowson, Marc-Alain; Beard, R Suzanne; Bulens, Sandra N; Mullins, James; Monroe, Stephan S; Bresee, Joseph; Sassano, Patricia; Cramer, Elaine H; Glass, Roger I

    2005-01-01

    An outbreak of norovirus gastroenteritis affected passengers on two consecutive cruises of ship X and continued on 4 subsequent cruises despite a 1-week sanitization. We documented transmission by food and person-to-person contact; persistence of virus despite sanitization onboard, including introductions of new strains; and seeding of an outbreak on land.

  3. Identification of RNA-Protein Interaction Networks Involved in the Norovirus Life Cycle

    PubMed Central

    Vashist, Surender; Urena, Luis; Chaudhry, Yasmin

    2012-01-01

    Human noroviruses are one of the major causes of acute gastroenteritis in the developed world, yet our understanding of their molecular mechanisms of genome translation and replication lags behind that for many RNA viruses. Due to the nonculturable nature of human noroviruses, many related members of the Caliciviridae family of small RNA viruses are often used as model systems to dissect the finer details of the norovirus life cycle. Murine norovirus (MNV) has provided one such system with which to study the basic mechanisms of norovirus translation and replication in cell culture. In this report we describe the use of riboproteomics to identify host factors that interact with the extremities of the MNV genome. This network of RNA-protein interactions contains many well-characterized host factors, including PTB, La, and DDX3, which have been shown to play a role in the life cycle of other RNA viruses. By using RNA coimmunoprecipitation, we confirmed that a number of the factors identified using riboproteomics are associated with the viral RNA during virus replication in cell culture. We further demonstrated that RNA inhibition-mediated knockdown of the intracellular levels of a number of these factors inhibits or slows norovirus replication in cell culture, allowing identification of new intracellular targets for this important group of pathogens. PMID:22933270

  4. Acute gastroenteritis outbreak caused by a GII.6 norovirus

    PubMed Central

    Luo, Ling-Fei; Qiao, Kun; Wang, Xiao-Guang; Ding, Ke-Ying; Su, Hua-Ling; Li, Cui-Zhen; Yan, Hong-Jing

    2015-01-01

    AIM: To report an acute gastroenteritis outbreak caused by a genogroup 2 genotype 6 (GII.6) strain norovirus in Shanghai, China. METHODS: Noroviruses are responsible for approximately half of all reported gastroenteritis outbreaks in many countries. Genogroup 2 genotype 4 strains are the most prevalent. Rare outbreaks caused by GII.6 strains have been reported. An acute gastroenteritis outbreak occurred in an elementary school in Shanghai in December of 2013. Field and molecular epidemiologic investigations were conducted. RESULTS: The outbreak was limited to one class in an elementary school located in southwest Shanghai. The age of the students ranged from 9 to 10 years. The first case emerged on December 10, 2013, and the last case emerged on December 14, 2013. The cases peaked on December 11, 2013, with 21 new cases. Of 45 students in the class, 32 were affected. The main symptom was gastroenteritis, and 15.6% (5/32) of the cases exhibited a fever. A field epidemiologic investigation showed the pathogen may have been transmitted to the elementary school from employees in a delicatessen via the first case student, who had eaten food from the delicatessen one day before the gastroenteritis episodes began. A molecular epidemiologic investigation identified the cause of the gastroenteritis as norovirus strain GII.6; the viral sequence of the student cases showed 100% homology with that of the shop employees. Genetic relatedness analyses showed that the new viral strain is closely related to previously reported GII.6 sequences, especially to a strain reported in Japan. CONCLUSION: This is the first report to show that norovirus strain GII.6 can cause a gastroenteritis outbreak. Thus, the prevalence of GII.6 noroviruses requires attention. PMID:25954103

  5. Multiple Norovirus Infections in a Birth Cohort in a Peruvian Periurban Community

    PubMed Central

    Saito, Mayuko; Goel-Apaza, Sonia; Espetia, Susan; Velasquez, Daniel; Cabrera, Lilia; Loli, Sebastian; Crabtree, Jean E.; Black, Robert E.; Kosek, Margaret; Checkley, William; Zimic, Mirko; Bern, Caryn; Cama, Vitaliano; Gilman, Robert H.; Xiao, L.; Kelleher, D.; Windle, H. J.; van Doorn, L. J.; Varela, M.; Verastegui, M.; Calderon, M.; Alva, A.; Roman, K.

    2014-01-01

    Background. Human noroviruses are among the most common enteropathogens globally, and are a leading cause of infant diarrhea in developing countries. However, data measuring the impact of norovirus at the community level are sparse. Methods. We followed a birth cohort of children to estimate norovirus infection and diarrhea incidence in a Peruvian community. Stool samples from diarrheal episodes and randomly selected nondiarrheal samples were tested by polymerase chain reaction for norovirus genogroup and genotype. Excretion duration and rotavirus coinfection were evaluated in a subset of episodes. Results. Two hundred twenty and 189 children were followed to 1 and 2 years of age, respectively. By 1 year, 80% (95% confidence interval [CI], 75%–85%) experienced at least 1 norovirus infection and by 2 years, 71% (95% CI, 65%–77%) had at least 1 episode of norovirus-associated diarrhea. Genogroup II (GII) infections were 3 times more frequent than genogroup 1 (GI) infections. Eighteen genotypes were found; GII genotype 4 accounted for 41%. Median excretion duration was 34.5 days for GII vs 8.5 days for GI infection (P = .0006). Repeat infections by the same genogroup were common, but repeat infections by the same genotype were rare. Mean length-for-age z score at 12 months was lower among children with prior norovirus infection compared to uninfected children (coefficient: −0.33 [95% CI, −.65 to −.01]; P = .04); the effect persisted at 24 months. Conclusions. Norovirus infection occurs early in life and children experience serial infections with multiple genotypes, suggesting genotype-specific immunity. An effective vaccine would have a substantial impact on morbidity, but may need to target multiple genotypes. PMID:24300042

  6. Multiple norovirus infections in a birth cohort in a Peruvian Periurban community.

    PubMed

    Saito, Mayuko; Goel-Apaza, Sonia; Espetia, Susan; Velasquez, Daniel; Cabrera, Lilia; Loli, Sebastian; Crabtree, Jean E; Black, Robert E; Kosek, Margaret; Checkley, William; Zimic, Mirko; Bern, Caryn; Cama, Vitaliano; Gilman, Robert H

    2014-02-01

    Human noroviruses are among the most common enteropathogens globally, and are a leading cause of infant diarrhea in developing countries. However, data measuring the impact of norovirus at the community level are sparse. We followed a birth cohort of children to estimate norovirus infection and diarrhea incidence in a Peruvian community. Stool samples from diarrheal episodes and randomly selected nondiarrheal samples were tested by polymerase chain reaction for norovirus genogroup and genotype. Excretion duration and rotavirus coinfection were evaluated in a subset of episodes. Two hundred twenty and 189 children were followed to 1 and 2 years of age, respectively. By 1 year, 80% (95% confidence interval [CI], 75%-85%) experienced at least 1 norovirus infection and by 2 years, 71% (95% CI, 65%-77%) had at least 1 episode of norovirus-associated diarrhea. Genogroup II (GII) infections were 3 times more frequent than genogroup 1 (GI) infections. Eighteen genotypes were found; GII genotype 4 accounted for 41%. Median excretion duration was 34.5 days for GII vs 8.5 days for GI infection (P = .0006). Repeat infections by the same genogroup were common, but repeat infections by the same genotype were rare. Mean length-for-age z score at 12 months was lower among children with prior norovirus infection compared to uninfected children (coefficient: -0.33 [95% CI, -.65 to -.01]; P = .04); the effect persisted at 24 months. Norovirus infection occurs early in life and children experience serial infections with multiple genotypes, suggesting genotype-specific immunity. An effective vaccine would have a substantial impact on morbidity, but may need to target multiple genotypes.

  7. Multiplex real-time RT-PCR for the simultaneous detection and quantification of GI, GII and GIV noroviruses.

    PubMed

    Farkas, Tibor; Singh, Amy; Le Guyader, Françoise S; La Rosa, Giuseppina; Saif, Linda; McNeal, Monica

    2015-10-01

    Noroviruses are important causes of acute gastroenteritis and are classified into six genogroups with GI, GII and GIV containing human pathogens. This high genetic diversity represents a significant challenge for diagnostic assay development. Genogroup specific monoplex and multiplex real time RT-PCR assays are widely used for the detection of GI and GII noroviruses. On the other hand, GIV norovirus detection is not part of routine laboratory diagnosis. This study describes the development and evaluation of a one tube, real time RT-PCR assay for the simultaneous detection and quantification of GI, GII and GIV noroviruses, including both GIV.1 (human) and GIV.2 (animal) strains. Assay performance was evaluated on a panel of norovirus positive clinical samples by comparison of monoplex and multiplex standard curves and Ct values. The multiplex assay demonstrated equal sensitivity and specificity to the monoplex assays and was able to detect all GI, GII and GIV noroviruses with Ct values equal to that of the monoplex assays. The multiplex assay described in this study will be instrumental for the better understanding of GIV norovirus epidemiology, including their possible zoonotic nature.

  8. Comparative efficacy of seven hand sanitizers against murine norovirus, feline calicivirus, and GII.4 norovirus.

    PubMed

    Park, Geun Woo; Barclay, Leslie; Macinga, David; Charbonneau, Duane; Pettigrew, Charles A; Vinjé, Jan

    2010-12-01

    Contaminated hands or inanimate surfaces can act as a source of infection during outbreaks of human norovirus infection. We evaluated the virucidal efficacy of seven hand sanitizers containing various active ingredients, such as ethanol, triclosan, and chlorhexidine, and compared their effectiveness against feline calicivirus (FCV), murine norovirus (MNV), and a GII.4 norovirus fecal extract. We also tested the efficacy of 50, 70, and 90% of ethanol and isopropanol. Reduction of viral infectivity was measured by plaque assay, and the number of genomic copies was determined with a TaqMan real-time reverse transcription PCR assay. Based on the results of a quantitative suspension test, only one ethanol-based product (72% ethanol, pH 2.9) and one triclosan-based product (0.1% triclosan, pH 3.0) reduced the infectivity of both MNV and FCV (by >2.6 and ≥3.4 log units, respectively). Four of the seven products were effective against either MNV or FCV, whereas chlorhexidine was ineffective against both viruses. For these hand sanitizers, no correlation was found between reduced infectivity and decline of viral RNA. Ethanol and isopropanol concentrations ≥70% reduced the infectivity of MNV by ≥2.6 log units, whereas 50 and 70% ethanol reduced the infectivity of FCV by ≥2.2 log units after exposure for 5 min. The susceptibility of FCV to low pH and the relative high susceptibility of MNV to alcohols suggest that both surrogate viruses should be considered for in vitro testing of hand sanitizers.

  9. The efficacy of X-ray does on murine norovirus-1 (MNV-1) in pure culture, half-shell oyster, salmon sushi, and tuna salad

    USDA-ARS?s Scientific Manuscript database

    In this investigation, we determined the efficacy of X-ray doses on reducing a human norovirus (HuNoV) surrogate [murine norovirus-1 (MNV-1)] in pure culture, half-shell oyster, salmon sushi and tuna salad. The pure culture (phosphate-buffer saline, pH 7.4), half-shell oyster, salmon sushi and tuna ...

  10. The efficacy of x-ray doses on murine norovirus-1 (MNV-1) in pure culture, half-shell oyster, salmon sushi, and tuna salad

    USDA-ARS?s Scientific Manuscript database

    n this investigation, we determined the efficacy of X-ray doses on reducing a human norovirus (HuNoV) surrogate [murine norovirus-1 (MNV-1)] in pure culture, half-shell oyster, salmon sushi and tuna salad. The pure culture (phosphate-buffer saline, pH 7.4), half-shell oyster, salmon sushi and tuna s...

  11. A Synergy Effect of Trisodium Phosphate and Ethanol on Inactivation of Murine Norovirus 1 on Lettuce and Bell Pepper.

    PubMed

    Kim, Eun-Jin; Lee, Young-Duck; Kim, Kwang-Yup; Park, Jong-Hyun

    2015-12-28

    The synergy effect of trisodium phosphate (TSP) and ethanol against murine norovirus 1 (MNV-1), as a surrogate for human noroviruses, on fresh produces was evaluated. More than 2% (w/v) of TSP effectively inactivated MNV-1. The single treatment of 1% TSP or 30% ethanol for 30 min was not effective on MNV-1; however, cotreatment showed inactivation of MNV-1 on stainless steel and the produces of lettuce and bell pepper under 15 min. The results suggest that cotreatment of TSP and ethanol at a low concentration and a short time of exposure might be useful for the reduction of norovirus in some produce.

  12. Human response to aircraft noise

    NASA Technical Reports Server (NTRS)

    Powell, Clemans A.; Fields, James M.

    1991-01-01

    The human auditory system and the perception of sound are discussed. The major concentration is on the annnoyance response and methods for relating the physical characteristics of sound to those psychosociological attributes associated with human response. Results selected from the extensive laboratory and field research conducted on human response to aircraft noise over the past several decades are presented along with discussions of the methodology commonly used in conducting that research. Finally, some of the more common criteria, regulations, and recommended practices for the control or limitation of aircraft noise are examined in light of the research findings on human response.

  13. Disinfection kinetics of murine norovirus using chlorine and chlorine dioxide.

    PubMed

    Lim, Mi Young; Kim, Ju-Mi; Ko, Gwangpyo

    2010-05-01

    We determined the disinfection efficiency of chlorine and chlorine dioxide (ClO(2)) using murine norovirus (MNV) and coliphage MS2 as surrogates for human norovirus. Experiments were performed in oxidant demand-free buffer (pH 7.2) at 5 degrees C and 20 degrees C. The extent of virus inactivation by a disinfectant was quantified using three different analytical methods: plaque, short template real-time TaqMan reverse transcriptase-polymerase chain reaction (RT-PCR), and long template RT-PCR assays. Rapid inactivation of MNV by both chlorine and chlorine dioxide was observed by the plaque assay. According to the efficiency factor Hom model, Ct values of 0.314mg/Lmin and 0.247mg/Lmin were required for a 4-log reduction of MNV at 5 degrees C by chlorine and chlorine dioxide, respectively. Lower Ct values were required at 20 degrees C. Both long template and short template RT-PCR assays significantly underestimated the virus inactivation compared to the plaque assay. Our study demonstrates that adequate treatment of water with either chlorine or ClO(2) is likely to effectively control the waterborne transmission of human norovirus.

  14. Human immune responses in cryptosporidiosis

    PubMed Central

    Borad, Anoli; Ward, Honorine

    2010-01-01

    Immune responses play a critical role in protection from, and resolution of, cryptosporidiosis. However, the nature of these responses, particularly in humans, is not completely understood. Both innate and adaptive immune responses are important. Innate immune responses may be mediated by Toll-like receptor pathways, antimicrobial peptides, prostaglandins, mannose-binding lectin, cytokines and chemokines. Cell-mediated responses, particularly those involving CD4+ T cells and IFN-γ play a dominant role. Mucosal antibody responses may also be involved. Proteins mediating attachment and invasion may serve as putative protective antigens. Further knowledge of human immune responses in cryptosporidiosis is essential in order to develop targeted prophylactic and therapeutic interventions. This review focuses on recent advances and future prospects in the understanding of human immune responses to Cryptosporidium infection. PMID:20210556

  15. Evaluation of real-time RT-PCR assays for detection and quantification of norovirus genogroups I and II.

    PubMed

    Rupprom, Kitwadee; Chavalitshewinkoon-Petmitr, Porntip; Diraphat, Pornphan; Kittigul, Leera

    2017-02-20

    Noroviruses are the leading cause of acute gastroenteritis in humans. Real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) is a promising molecular method for the detection of noroviruses. In this study, the performance of three TaqMan real-time RT-PCR assays was assessed, which were one commercially available real-time RT-PCR kit (assay A: Norovirus Real Time RT-PCR kit) and two in-house real-time RT-PCR assays (assay B: LightCycler RNA Master Hybprobe and assay C: RealTime ready RNA Virus Master). Assays A and B showed higher sensitivity than assay C for norovirus GI, while they all had the same sensitivity (10(3) DNA copies/mL) for GII DNA standard controls. Assay B had the highest efficiency for both genogroups. No cross-reactivity was observed among GI and GII noroviruses, rotavirus, hepatitis A virus, and poliovirus. The detection rates of these assays in GI and GII norovirus-positive fecal samples were not significantly different. However, the mean quantification cycle (Cq) value of assay B for GII was lower than assays A and C with statistical significance (P-value, 0.000). All three real-time RT-PCR assays could detect a variety of noroviruses including GI.2, GII.2, GII.3, GII.4, GII.6, GII.12, GII.17, and GII.21. This study suggests assay B as a suitable assay for the detection and quantification of noroviruses GI and GII due to good analytical sensitivity and higher performance to amplify norovirus on DNA standard controls and clinical samples.

  16. Development of an optimized RNA-based murine norovirus reverse genetics system.

    PubMed

    Yunus, Muhammad Amir; Chung, Liliane Man Wah; Chaudhry, Yasmin; Bailey, Dalan; Goodfellow, Ian

    2010-10-01

    Murine norovirus (MNV), identified in 2003, is the only norovirus which replicates efficiently in tissue culture and as a result has been used extensively as a model for human noroviruses, a major cause of acute gastroenteritis. The current report describes the generation of a new approach to reverse genetics recovery of genetically defined MNV that relies on the transfection of in vitro transcribed capped RNA directly into cells. The use of the recently developed ScriptCap post-transcriptional enzymatic capping system, followed by optimized Neon mediated electroporation of the highly permissive RAW 264.7 cells, resulted in the rapid and robust recovery of infectious MNV. Transfection of cells capable of supporting virus replication but not permissive to virus infection, namely human or hamster kidney cells, also resulted in robust recovery of infectious virus without subsequent amplification by multiple rounds of re-infection. This latter system may provide a reproducible method to measure the specific infectivity of mutant norovirus RNA allowing the accurate quantitation of the effect of mutations on norovirus replication.

  17. Development of an optimized RNA-based murine norovirus reverse genetics system

    PubMed Central

    Yunus, Muhammad Amir; Chung, Liliane Man Wah; Chaudhry, Yasmin; Bailey, Dalan; Goodfellow, Ian

    2010-01-01

    Murine norovirus (MNV), identified in 2003, is the only norovirus which replicates efficiently in tissue culture and as a result has been used extensively as a model for human noroviruses, a major cause of acute gastroenteritis. The current report describes the generation of a new approach to reverse genetics recovery of genetically defined MNV that relies on the transfection of in vitro transcribed capped RNA directly into cells. The use of the recently developed ScriptCap post-transcriptional enzymatic capping system, followed by optimized Neon mediated electroporation of the highly permissive RAW 264.7 cells, resulted in the rapid and robust recovery of infectious MNV. Transfection of cells capable of supporting virus replication but not permissive to virus infection, namely human or hamster kidney cells, also resulted in robust recovery of infectious virus without subsequent amplification by multiple rounds of re-infection. This latter system may provide a reproducible method to measure the specific infectivity of mutant norovirus RNA allowing the accurate quantitation of the effect of mutations on norovirus replication. PMID:20637238

  18. Secretory pathway antagonism by calicivirus homologues of Norwalk virus nonstructural protein p22 is restricted to noroviruses.

    PubMed

    Sharp, Tyler M; Crawford, Sue E; Ajami, Nadim J; Neill, Frederick H; Atmar, Robert L; Katayama, Kazuhiko; Utama, Budi; Estes, Mary K

    2012-09-03

    Our previous report that the Norwalk virus nonstructural protein p22 is an antagonist of the cellular secretory pathway suggests a new aspect of norovirus/host interaction. To explore conservation of function of this highly divergent calicivirus protein, we examined the effects of p22 homologues from four human and two murine noroviruses, and feline calicivirus on the secretory pathway. All human noroviruses examined induced Golgi disruption and inhibited protein secretion, with the genogroup II.4 Houston virus being the most potent antagonist. Genogroup II.6 viruses have a conserved mutation in the mimic of an Endoplasmic Reticulum export signal (MERES) motif that is highly conserved in human norovirus homologues of p22 and is critical for secretory pathway antagonism, and these viruses had reduced levels of Golgi disruption and inhibition of protein secretion. p22 homologues from both persistent and nonpersistent strains of murine norovirus induced Golgi disruption, but only mildly inhibited cellular protein secretion. Feline calicivirus p30 did not induce Golgi disruption or inhibit cellular protein secretion. These differences confirm a norovirus-specific effect on host cell secretory pathway antagonism by homologues of p22, which may affect viral replication and/or cellular pathogenesis.

  19. Secretory pathway antagonism by calicivirus homologues of Norwalk virus nonstructural protein p22 is restricted to noroviruses

    PubMed Central

    2012-01-01

    Background Our previous report that the Norwalk virus nonstructural protein p22 is an antagonist of the cellular secretory pathway suggests a new aspect of norovirus/host interaction. To explore conservation of function of this highly divergent calicivirus protein, we examined the effects of p22 homologues from four human and two murine noroviruses, and feline calicivirus on the secretory pathway. Findings All human noroviruses examined induced Golgi disruption and inhibited protein secretion, with the genogroup II.4 Houston virus being the most potent antagonist. Genogroup II.6 viruses have a conserved mutation in the mimic of an Endoplasmic Reticulum export signal (MERES) motif that is highly conserved in human norovirus homologues of p22 and is critical for secretory pathway antagonism, and these viruses had reduced levels of Golgi disruption and inhibition of protein secretion. p22 homologues from both persistent and nonpersistent strains of murine norovirus induced Golgi disruption, but only mildly inhibited cellular protein secretion. Feline calicivirus p30 did not induce Golgi disruption or inhibit cellular protein secretion. Conclusions These differences confirm a norovirus-specific effect on host cell secretory pathway antagonism by homologues of p22, which may affect viral replication and/or cellular pathogenesis. PMID:22943503

  20. Management of health risks associated with oysters harvested from a norovirus contaminated area, Ireland, February-March 2010.

    PubMed

    Doré, B; Keaveney, S; Flannery, J; Rajko-Nenow, P

    2010-05-13

    Oysters from a harvesting area responsible for outbreaks of gastroenteritis were relaid at a clean seawater site and subsequently depurated in tanks of purified seawater at elevated temperatures. This combined treatment reduced norovirus levels to those detected prior to the outbreak. On the basis of norovirus monitoring the sale of treated oysters was permitted although the harvest area remained closed for direct sale of oysters. No reports of illness have been associated with the consumption of treated oysters.

  1. Specificity and kinetics of norovirus binding to magnetic bead- conjugated histo-blood group antigens

    USDA-ARS?s Scientific Manuscript database

    Histo-blood group antigens (HBGA) have been identified as candidate receptors for human norovirus (NOR). Type A, type H1, and Lewis histo-blood group antigens (HBGAs) in humans have been identified as major targets for NOR binding. Pig HBGA-conjugated magnetic beads have been utilized as a means ...

  2. Rapid detection of hepatitis A virus and murine norovirus in hemocytes of contaminated oysters

    USDA-ARS?s Scientific Manuscript database

    The human enteric pathogens, hepatitis A virus and human norovirus, have been shown to contaminate molluscan shellfish and cause foodborne disease in consumers. Rapid viral extraction methods are needed to replace current time consuming methods, which use whole oysters or dissected tissues. In our ...

  3. Evaluation of various real-time reverse transcription quantitative PCR assays for norovirus detection.

    PubMed

    Yoo, Ju Eun; Lee, Cheonghoon; Park, SungJun; Ko, GwangPyo

    2017-02-01

    Human noroviruses are widespread and contagious viruses causing nonbacterial gastroenteritis. Real-time reverse transcription quantitative PCR (real-time RT-qPCR) is currently the gold standard for sensitive and accurate detection for these pathogens and serves as a critical tool in outbreak prevention and control. Different surveillance teams, however, may use different assays and variability in specimen conditions may lead to disagreement in results. Furthermore, the norovirus genome is highly variable and continuously evolving. These issues necessitate the re-examination of the real-time RT-qPCR's robustness in the context of accurate detection as well as the investigation of practical strategies to enhance assay performance. Four widely referenced real-time RT-qPCR assays (Assay A-D) were simultaneously performed to evaluate characteristics such as PCR efficiency, detection limit, as well as sensitivity and specificity with RT-PCR, and to assess the most accurate method for detecting norovirus genogroups I and II. Overall, Assay D was evaluated to be the most precise and accurate assay in this study. A Zen internal quencher, which decreases nonspecific fluorescence during the PCR reaction, was added to Assay D's probe which further improved assay performance. This study compared several detection assays for noroviruses and an improvement strategy based on such comparisons provided useful characterizations of a highly optimized real-time RT-qPCR assay for norovirus detection.

  4. Epidemiology of Acute Gastroenteritis Outbreaks Caused by Human Calicivirus (Norovirus and Sapovirus) in Catalonia: A Two Year Prospective Study, 2010-2011

    PubMed Central

    Martinez, Ana; Moreno, Antonio; Camps, Neus

    2016-01-01

    Background The epidemiology of cases of acute gastroenteritis (AGE) of viral etiology is a relevant public health issue. Due to underreporting, the study of outbreaks is an accepted approach to investigate their epidemiology. The objective of this study was to investigate the epidemiological characteristics of AGE outbreaks due to norovirus (NoV) and sapovirus (SV) in Catalonia. Material and Methods Prospective study of AGE outbreaks of possible viral etiology notified during two years in Catalonia. NoV and SV were detected by real time reverse transcription polymerase (RT-PCR). Results A total of 101 outbreaks were registered affecting a total of 2756 persons and 12 hospitalizations (hospitalization rate: 0.8x1,000,000 persons-year); 49.5% of outbreaks were foodborne, 45.5% person to person and 5% waterborne. The distribution of outbreaks according to the setting showed a predominance of catering services (39.6%), nursing homes and long term care facilities (26.8%) and schools (11.9%). The median number of cases per outbreak was 17 (range 2–191). The total Incidence rate (IR) was 18.3 per 100,000 persons-years (95%CI: 17.6–19.0). The highest IR was in persons aged ≥65 years (43.6x100,000 (95% CI: 41.0–46.2)) (p<0.001). A total of 1065 samples were analyzed with a positivity rate of 60.8%. 98% of positive samples were NoV (GII 56.3%; GI 4.2%; GII+GI 4.2%; non- typable 33.0%). SV was identified in two person-to-person transmission outbreaks in children. Conclusions These results confirm the relevance of viral AGE outbreaks, both foodborne and person-to-person, especially in institutionalized persons. SV should be taken into account when investigating viral AGE outbreaks. PMID:27120472

  5. Epidemiology of Acute Gastroenteritis Outbreaks Caused by Human Calicivirus (Norovirus and Sapovirus) in Catalonia: A Two Year Prospective Study, 2010-2011.

    PubMed

    Torner, Nuria; Martinez, Ana; Broner, Sonia; Moreno, Antonio; Camps, Neus; Domínguez, Angela

    2016-01-01

    The epidemiology of cases of acute gastroenteritis (AGE) of viral etiology is a relevant public health issue. Due to underreporting, the study of outbreaks is an accepted approach to investigate their epidemiology. The objective of this study was to investigate the epidemiological characteristics of AGE outbreaks due to norovirus (NoV) and sapovirus (SV) in Catalonia. Prospective study of AGE outbreaks of possible viral etiology notified during two years in Catalonia. NoV and SV were detected by real time reverse transcription polymerase (RT-PCR). A total of 101 outbreaks were registered affecting a total of 2756 persons and 12 hospitalizations (hospitalization rate: 0.8x1,000,000 persons-year); 49.5% of outbreaks were foodborne, 45.5% person to person and 5% waterborne. The distribution of outbreaks according to the setting showed a predominance of catering services (39.6%), nursing homes and long term care facilities (26.8%) and schools (11.9%). The median number of cases per outbreak was 17 (range 2-191). The total Incidence rate (IR) was 18.3 per 100,000 persons-years (95%CI: 17.6-19.0). The highest IR was in persons aged ≥65 years (43.6x100,000 (95% CI: 41.0-46.2)) (p<0.001). A total of 1065 samples were analyzed with a positivity rate of 60.8%. 98% of positive samples were NoV (GII 56.3%; GI 4.2%; GII+GI 4.2%; non- typable 33.0%). SV was identified in two person-to-person transmission outbreaks in children. These results confirm the relevance of viral AGE outbreaks, both foodborne and person-to-person, especially in institutionalized persons. SV should be taken into account when investigating viral AGE outbreaks.

  6. Effect of UV light on the inactivation of recombinant human adenovirus and murine norovirus seeded in seawater in shellfish depuration tanks.

    PubMed

    Garcia, Lucas A T; Nascimento, Mariana A; Barardi, Célia R M

    2015-03-01

    Shellfish depuration is a process that aims to eliminate pathogens from mollusk tissues. Seawater disinfection during the depuration process is important and ultraviolet (UV) light treatment is the most used method worldwide. Viral models are usually employed as surrogates of fastidious viruses in viability studies. The aim of this study was to employ methods based on green fluorescent protein (GFP) fluorescence and plaque forming units to detect, respectively, recombinant adenovirus (rAdV-GFP) and murine norovirus (MNV) artificially seeded in environmental matrices. These assays were applied to assess the inactivation of rAdV-GFP and MNV in seawater in recirculation shellfish depuration tanks with and without UV light treatment. Kinetics of rAdV GFP-expression was previously measured by UV-spectrophotometer. Flow cytometry (FC), fluorescence microscopy (FM), and plaque assay were used to determine virus titer and detection limits. The influence of the environmental matrix on the performance of the methods was prior determined using either drinking water or filtered seawater seeded with rAdV-GFP. Disinfection of seeded seawater was evaluated with and without UV treatment. The time of 24-h post-infection was established as ideal for fluorescence detection on rAdV-GFP infected cells. FC showed lower sensitivity, when compared to FM, which was similar to plaque assay. Seawater disinfection on depuration tanks was promising and rAdV-GFP declined 99.99 % after 24 and 48 h with and without UV treatment, respectively. MNV was completely inactivated after 24 h in both treatments. As conclusion, the depuration tanks were effective to inactivate rAdV-GFP and MNV and the UV disinfection treatment accelerated the process.

  7. Characterisation of a household norovirus outbreak occurred in Valencia (Spain).

    PubMed

    Carmona-Vicente, Noelia; Fernández-Jiménez, Manuel; Vila-Vicent, Susana; Rodríguez-Díaz, Jesús; Buesa, Javier

    2016-03-12

    Human noroviruses (NoVs) are the main cause of non-bacterial gastroenteritis worldwide. Several studies have linked human susceptibility to NoVs with the expression of histo-blood group antigens (HBGAs). In January 2012, a NoV gastroenteritis outbreak affected a household in Valencia, Spain, and the personal susceptibility to NoV was investigated. To reach this aim 8 members of the affected household were recruited for this study and their secretor status, ABO and Lewis antigens were determined. NoV-specific saliva IgA and serum IgG antibody titers were analyzed. Their capacity to block viral binding to saliva receptors was analyzed, using virus-like particles (VLPs) of the NoV GII.4 genotype, 2006b variant, and saliva from a secretor O blood type donor. The most relevant finding was that an asymptomatic non-secretor individual shed NoVs in his stools. Interestingly, anti-NoV IgA antibody titers in saliva from secretor and non-secretor individuals showed no differences. On the contrary, high titers of NoV-specific IgG antibody were found in both convalescent sera and in sera collected 1 year post-infection, but only from secretor individuals. NoV GII.4-2006b VLP binding to receptors present in the saliva was efficiently blocked only by sera from secretor positive individuals. Despite the small number of individuals involved in this outbreak, this study reinforces the idea that susceptibility to human NoV is both dependent on the HBGA profile of the individuals as well as on the viral genotype and variant. We also show that the immunity to NoV lasts for at least 1 year after infection, demonstrating that symptomatic infections strongly stimulate immune responses.

  8. Norovirus: U.S. Trends and Outbreaks

    MedlinePlus

    ... Norovirus outbreaks can also occur from fecal (stool) contamination of certain foods at their source. For example, oysters harvested from contaminated water and raspberries irrigated with contaminated water have caused ...

  9. Enterovirus and Norovirus Monitoring under UCMR3

    EPA Science Inventory

    This presentation describes the Unregulated Contaminant Monitoring Rule round 3 (UCMR3) monitoring program for enterovirus and norovirus in groundwater. It provides the data on microbial indicators and virus occurrence during the monitoring period. Enteric virus occurrence was ab...

  10. Noroviruses: a challenge for military forces.

    PubMed

    Delacour, H; Dubrous, P; Koeck, J L

    2010-12-01

    For military forces, the control of infectious acute gastroenteritis constitutes an old, constant and unsolved concern. Recent epidemiological studies suggest that the common bacterial causes are being overtaken by viruses. Norviruses are the most alarming group and norovirus outbreaks in military forces are regularly reported. Illness is generally mild and characterised by acute vomiting and diarrhoea, which lasts for a few days on average, but may be severe and potentially life-threatening in subjects who are already dehydrated due to daily activity. Moreover, outbreaks may diminish operational effectiveness. Prevention of norovirus infection currently relies on strict application of personal and collective hygiene rules including isolation of the cases, to the greatest possible extent. Although noroviruses are frequently mentioned as the cause of gastroenteritis outbreaks in troops deployed overseas, laboratory diagnosis is rarely done. So their real burden in military forces remains unclear and further epidemiological studies are required to determine the full impact of norovirus gastroenteritis on troops.

  11. Enterovirus and Norovirus Monitoring under UCMR3

    EPA Science Inventory

    This presentation describes the Unregulated Contaminant Monitoring Rule round 3 (UCMR3) monitoring program for enterovirus and norovirus in groundwater. It provides the data on microbial indicators and virus occurrence during the monitoring period. Enteric virus occurrence was ab...

  12. Predictive Model for Inactivation of Feline Calicivirus, a Norovirus Surrogate, by Heat and High Hydrostatic Pressure▿

    PubMed Central

    Buckow, Roman; Isbarn, Sonja; Knorr, Dietrich; Heinz, Volker; Lehmacher, Anselm

    2008-01-01

    Noroviruses, which are members of the Caliciviridae family, represent the leading cause of nonbacterial gastroenteritis in developed countries; such norovirus infections result in high economic costs for health protection. Person-to-person contact, contaminated water, and foods, especially raw shellfish, vegetables, and fruits, can transmit noroviruses. We inactivated feline calicivirus, a surrogate for the nonculturable norovirus, in cell culture medium and mineral water by heat and high hydrostatic pressure. Incubation at ambient pressure and 75°C for 2 min as well as treatment at 450 MPa and 15°C for 1 min inactivated more than 7 log10 PFU of calicivirus per ml in cell culture medium or mineral water. The heat and pressure time-inactivation curves obtained with the calicivirus showed tailing in the logarithmic scale. Modeling by nth-order kinetics of the virus inactivation was successful in predicting the inactivation of the infective virus particles. The developed model enables the prediction of the calicivirus reduction in response to pressures up to 500 MPa, temperatures ranging from 5 to 75°C, and various treatment times. We suggest high pressure for processing of foods to reduce the health threat posed by noroviruses. PMID:18156330

  13. Norovirus outbreaks on commercial cruise ships: a systematic review and new targets for the public health agenda.

    PubMed

    Bert, Fabrizio; Scaioli, Giacomo; Gualano, Maria Rosaria; Passi, Stefano; Specchia, Maria Lucia; Cadeddu, Chiara; Viglianchino, Cristina; Siliquini, Roberta

    2014-06-01

    Noroviruses are recognized as the leading cause of human acute viral gastroenteritis worldwide. The rate of outbreaks on cruise ships has grown significantly in recent years. Given the potentially harmful consequences of outbreaks for passengers and crewmembers and the subsequently high costs for cruise companies, disease outbreaks on cruise ships represent a serious public health issue. The aim of our study was to systematically review published studies related to Norovirus outbreaks on commercial cruise ships. We searched the PubMed and Scopus scientific databases. We included eligible studies published from January 1990 to July 2013 that were written in English and described infectious episodes involving at least two passengers and/or crewmembers on a commercial cruise ship. As a result, 15 studies and seven reviews met the inclusion criteria, describing a total of 127 outbreaks. The majority of the cases were reported in Europe and the USA, affecting <1 to 74% of the embarked passengers. In the majority of the studies, stool samples and/or serum specimens from ill passengers were collected and tested for laboratory confirmation. Twelve studies reported that an ad-hoc questionnaire was administered. Fifteen studies investigated the possible source of infection which was contaminated food in the majority of cases. Our findings suggest a strong need for the monitoring and implementation of preventive measures in semi-closed communities, such as cruise ships. It would be advisable to strengthen all relevant initiatives in order to improve the detection of, response to and control of Norovirus outbreaks on cruise ships.

  14. Norovirus Recombinant Strains Isolated from Gastroenteritis Outbreaks in Southern Brazil, 2004–2011

    PubMed Central

    Leite, José Paulo Gagliardi; Miagostovich, Marize Pereira

    2016-01-01

    Noroviruses are recognized as one of the leading causes of viral acute gastroenteritis, responsible for almost 50% of acute gastroenteritis outbreaks worldwide. The positive single-strand RNA genome of noroviruses presents a high mutation rate and these viruses are constantly evolving by nucleotide mutation and genome recombination. Norovirus recombinant strains have been detected as causing acute gastroenteritis outbreaks in several countries. However, in Brazil, only one report of a norovirus recombinant strain (GII.P7/GII.20) has been described in the northern region so far. For this study, 38 norovirus strains representative of outbreaks, 11 GII.4 and 27 non-GII.4, were randomly selected and amplified at the ORF1/ORF2 junction. Genetic recombination was identified by constructing phylogenetic trees of the polymerase and capsid genes, and further SimPlot and Bootscan analysis of the ORF1/ORF2 overlap. Sequence analysis revealed that 23 out of 27 (85%) non-GII.4 noroviruses were recombinant strains, characterized as: GII.P7/GII.6 (n = 9); GIIP.g/GII.12 (n = 4); GII.P16/GII.3 (n = 4); GII.Pe/GII.17 (n = 2); GII.P7/GII.14 (n = 1); GII.P13/GII.17 (n = 1); GII.P21/GII.3 (n = 1); and GII.P21/GII.13 (n = 1). On the other hand, among the GII.4 variants analyzed (Den Haag_2006b and New Orleans_2009) no recombination was observed. These data revealed the great diversity of norovirus recombinant strains associated with outbreaks, and describe for the first time these recombinant types circulating in Brazil. Our results obtained in southern Brazil corroborate the previous report for the northern region, demonstrating that norovirus recombinant strains are circulating more frequently than we expected. In addition, these results emphasize the relevance of including ORF1/ORF2-based analysis in surveillance studies as well as the importance of characterizing strains from other Brazilian regions to obtain epidemiological data for norovirus recombinant strains circulating in the

  15. Innate Resistance and Susceptibility to Norovirus Infection

    SciTech Connect

    Nordgren, Johan; Sharma, Sumit; Kambhampati, Anita; Lopman, Ben; Svensson, Lennart; Dutch, Rebecca Ellis

    2016-04-26

    The notion that certain individuals appear more or less susceptible to infections or to specific microbes is not new, but, until recently, it was assumed that clinical outcome of an infection was mainly owing to virulence factors of the microorganism. Relatively little attention has been given to host genetic factors involved in innate or adaptive immunity or expression of pathogen receptors. A remarkable example of susceptibility dependence is the strong Mendelian trait resistance to the most common noroviruses among individuals with a nonsense mutation in chromosome 19. Norovirus is recognized as the leading cause of gastroenteritis worldwide, affecting children and adults alike. Noroviruses are highly contagious and genetically diverse RNA viruses, but not all individuals are susceptible to infection to the same norovirus genotypes. Presence of histo-blood group antigens (HBGAs) on gut epithelial surfaces is essential for susceptibility to many norovirus genotypes. The synthesis of these HBGAs, specifically of the ABH and Lewis families, requires the use of several fucosyl and glycosyltransferases encoded by the FUT2, FUT3, and ABH genes. Polymorphisms in these genes vary considerably depending on ethnicity, with a homozygous nonsense mutation (individuals called non-secretors) in the FUT2 gene occurring in approximately 5%–50% of different populations worldwide. Secretor status also affects gut microbiota composition, including HBGA-expressing bacteria and bacteria inducing fucosylation in the gut. These could be intermediary factors that govern norovirus susceptibility.

  16. Innate Resistance and Susceptibility to Norovirus Infection

    DOE PAGES

    Nordgren, Johan; Sharma, Sumit; Kambhampati, Anita; ...

    2016-04-26

    The notion that certain individuals appear more or less susceptible to infections or to specific microbes is not new, but, until recently, it was assumed that clinical outcome of an infection was mainly owing to virulence factors of the microorganism. Relatively little attention has been given to host genetic factors involved in innate or adaptive immunity or expression of pathogen receptors. A remarkable example of susceptibility dependence is the strong Mendelian trait resistance to the most common noroviruses among individuals with a nonsense mutation in chromosome 19. Norovirus is recognized as the leading cause of gastroenteritis worldwide, affecting children andmore » adults alike. Noroviruses are highly contagious and genetically diverse RNA viruses, but not all individuals are susceptible to infection to the same norovirus genotypes. Presence of histo-blood group antigens (HBGAs) on gut epithelial surfaces is essential for susceptibility to many norovirus genotypes. The synthesis of these HBGAs, specifically of the ABH and Lewis families, requires the use of several fucosyl and glycosyltransferases encoded by the FUT2, FUT3, and ABH genes. Polymorphisms in these genes vary considerably depending on ethnicity, with a homozygous nonsense mutation (individuals called non-secretors) in the FUT2 gene occurring in approximately 5%–50% of different populations worldwide. Secretor status also affects gut microbiota composition, including HBGA-expressing bacteria and bacteria inducing fucosylation in the gut. These could be intermediary factors that govern norovirus susceptibility.« less

  17. Multiple norovirus outbreaks among workplace canteen users in Finland, July 2006.

    PubMed

    Makary, P; Maunula, L; Niskanen, T; Kuusi, M; Virtanen, M; Pajunen, S; Ollgren, J; Tran Minh, N N

    2009-03-01

    Multiple gastroenteritis outbreaks occurred between 25 and 31 July 2006 in 10 workplace canteens in south-western Finland. One vegetable processing plant provided raw vegetables to all the canteens. We conducted cohort studies in the three most visited canteens and environmental investigations in the kitchens and the plant. Patients' stools, food, water and environmental samples were tested for enteric bacteria and viruses. Of the three canteens, 150/273 respondents (response rate 82%) had gastroenteritis. Consumption of mixed raw vegetables was significantly associated with the illness but no single vegetable explains the outbreak. An identical norovirus GII.1 genotype was detected from all genotyped patient samples. Water, food, and environmental samples were negative for norovirus. The facilities had appropriate hygienic conditions and no staff member had gastroenteritis prior to the outbreak. Tracing back the vegetables to the farm level proved unsuccessful. This was the largest foodborne norovirus outbreak in Finland.

  18. A State-by-State Assessment of Food Service Regulations for Prevention of Norovirus Outbreaks.

    PubMed

    Kambhampati, Anita; Shioda, Kayoko; Gould, L Hannah; Sharp, Donald; Brown, Laura G; Parashar, Umesh D; Hall, Aron J

    2016-09-01

    Noroviruses are the leading cause of foodborne disease in the United States. Foodborne transmission of norovirus is often associated with contamination of food during preparation by an infected food worker. The U.S. Food and Drug Administration's Food Code provides model food safety regulations for preventing transmission of foodborne disease in restaurants; however, adoption of specific provisions is at the discretion of state and local governments. We analyzed the food service regulations of all 50 states and the District of Columbia (i.e., 51 states) to describe differences in adoption of norovirus-related Food Code provisions into state food service regulations. We then assessed potential correlations between adoption of these regulations and characteristics of foodborne norovirus outbreaks reported to the National Outbreak Reporting System from 2009 through 2014. Of the 51 states assessed, all (100%) required food workers to wash their hands, and 39 (76%) prohibited bare-hand contact with ready-to-eat food. Thirty states (59%) required exclusion of staff with vomiting and diarrhea until 24 h after cessation of symptoms. Provisions requiring a certified food protection manager (CFPM) and a response plan for contamination events (i.e., vomiting) were least commonly adopted; 26 states (51%) required a CFPM, and 8 (16%) required a response plan. Although not statistically significant, states that adopted the provisions prohibiting bare-hand contact (0.45 versus 0.74, P =0.07), requiring a CFPM (0.38 versus 0.75, P =0.09), and excluding ill staff for ≥24 h after symptom resolution (0.44 versus 0.73, P =0.24) each reported fewer foodborne norovirus outbreaks per million person-years than did those states without these provisions. Adoption and compliance with federal recommended food service regulations may decrease the incidence of foodborne norovirus outbreaks.

  19. Transmission of Norovirus Within Households in Quininde, Ecuador.

    PubMed

    Gastañaduy, Paul A; Vicuña, Yosselin; Salazar, Fabian; Broncano, Nely; Gregoricus, Nicole; Vinjé, Jan; Chico, Martha; Parashar, Umesh D; Cooper, Philip J; Lopman, Ben

    2015-09-01

    We studied the transmission of norovirus infection in households in Quininde, Ecuador. Among household contacts of norovirus positive children with diarrhea, norovirus negative children with diarrhea and asymptomatic controls, infection attack rates were 33%, 8% and 18%, respectively (N = 45, 36, 83). Infection attack rates were higher when index children had a higher viral load.

  20. Evaluation of methods using celite to concentrate norovirus, adenovirus and enterovirus from wastewater

    EPA Science Inventory

    Enteroviruses, noroviruses and adenoviruses are among the most common viruses infecting humans worldwide. These viruses are shed in the feces of infected individuals and can accumulate in wastewater. Therefore, wastewater is a source of a potentially diverse group of enteric viru...

  1. Use of Low-Density DNA Microarrays and Photopolymerization for Genotyping Foodborne-Associated Noroviruses

    USDA-ARS?s Scientific Manuscript database

    Human noroviruses cause up to 21 million cases of foodborne disease in the United States annually and are the most common cause of acute gastroenteritis in industrialized countries. To reduce the burden of foodborne disease associated with viruses, the use of low density DNA microarrays in conjunct...

  2. Propidium monoazide reverse transcription PCR and RT-qPCR for detecting infectious enterovirus and norovirus

    EPA Science Inventory

    Presently there is no established cell line or small animal model that allows for the detection of infectious human norovirus. Current methods based on RT-PCR and RT-qPCR detect both infectious and non-infectious virus and thus the conclusions that may be drawn regarding the publ...

  3. Evaluation of methods using celite to concentrate norovirus, adenovirus and enterovirus from wastewater

    EPA Science Inventory

    Enteroviruses, noroviruses and adenoviruses are among the most common viruses infecting humans worldwide. These viruses are shed in the feces of infected individuals and can accumulate in wastewater. Therefore, wastewater is a source of a potentially diverse group of enteric viru...

  4. Propidium monoazide reverse transcription PCR and RT-qPCR for detecting infectious enterovirus and norovirus

    EPA Science Inventory

    Presently there is no established cell line or small animal model that allows for the detection of infectious human norovirus. Current methods based on RT-PCR and RT-qPCR detect both infectious and non-infectious virus and thus the conclusions that may be drawn regarding the publ...

  5. 77 FR 19534 - Medical Devices; Immunology and Microbiology Devices; Classification of Norovirus Serological...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 866 Medical Devices; Immunology and Microbiology Devices; Classification of Norovirus Serological Reagents; Correction AGENCY: Food and Drug Administration...

  6. The effects of x-ray treatments on bioaccumulated murine norovirus-1 (MNV-1) and survivability, inherent microbiota, color, and firmness of Atlantic oysters (Crassostrea virginica) during storage at 5°C for 20 days

    USDA-ARS?s Scientific Manuscript database

    In this study, we investigated the inactivation of human norovirus (HuNoV) surrogate Murine norovirus (MNV-1) by X-ray in whole-shell Atlantic oysters (Crassostrea virginica). We also investigated the effects of X-ray treatments on the survivability, inherent microbiota, color, and firmness of treat...

  7. Genetically distinct genogroup IV norovirus strains identified in wastewater.

    PubMed

    Kitajima, Masaaki; Rachmadi, Andri T; Iker, Brandon C; Haramoto, Eiji; Gerba, Charles P

    2016-12-01

    We investigated the prevalence and genetic diversity of genogroup IV norovirus (GIV NoV) strains in wastewater in Arizona, United States, over a 13-month period. Among 50 wastewater samples tested, GIV NoVs were identified in 13 (26 %) of the samples. A total of 47 different GIV NoV strains were identified, which were classified into two genetically distinct clusters: the GIV.1 human cluster and a unique genetic cluster closely related to strains previously identified in Japanese wastewater. The results provide additional evidence of the considerable genetic diversity among GIV NoV strains through the analysis of wastewater containing virus strains shed from all populations.

  8. Type-specific and cross-reactive antibodies and T cell responses in norovirus VLP immunized mice are targeted both to conserved and variable domains of capsid VP1 protein.

    PubMed

    Malm, Maria; Tamminen, Kirsi; Vesikari, Timo; Blazevic, Vesna

    2016-10-01

    Norovirus (NoV)-specific antibodies, which block binding of the virus-like particles (VLPs) to the cell receptors are conformation dependent and directed towards the most exposed domain of the NoV capsid VP1 protein, the P2 domain. Limited data are available on the antibodies directed to other domains of the VP1, and even less on the NoV VP1-specific T cell epitopes. In here, BALB/c mice were immunized with six VLPs derived from NoV GII.4-1999, GII.4-2009 (New Orleans), GII.4-2012 (Sydney), GII.12, GI.1, and G1.3. Serum immunoglobulin G binding antibodies, histo-blood group antigen blocking antibodies and T cell responses using type-specific and heterologous NoV VLPs, P-dimers and 76 overlapping synthetic peptides, spanning the entire 539 amino acid sequence of GII.4 VP1, were determined. The results showed that at least half of the total antibody content is directed towards conserved S domain of the VP1. Only a small fraction (<1%) of the VP1 binding antibodies were blocking/neutralizing. With the use of matrix peptide pools and individual peptides, seven CD4(+) and CD8(+) T cell restricted epitopes were mapped, two located in S domain, four in P2 domain and one in P1 domain of NoV VP1. The epitopes were GII.4 strain-specific but also common GII.4 genotype-specific T cell epitopes were identified. More importantly, the results suggest a 9-amino acids long sequence ((318)PAPLGTPDF(326)) in P2 domain of VP1 as a universal NoV genogroup II-specific CD8(+) T cell epitope. Distribution of the T cell epitopes alongside the capsid VP1 indicates the need of the complete protein for high immunogenicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Protective role of murine norovirus against Pseudomonas aeruginosa acute pneumonia.

    PubMed

    Thépaut, Marion; Grandjean, Teddy; Hober, Didier; Lobert, Pierre-Emmanuel; Bortolotti, Perrine; Faure, Karine; Dessein, Rodrigue; Kipnis, Eric; Guery, Benoit

    2015-09-04

    The murine norovirus (MNV) is a recently discovered mouse pathogen, representing the most common contaminant in laboratory mouse colonies. Nevertheless, the effects of MNV infection on biomedical research are still unclear. We tested the hypothesis that MNV infection could alter immune response in mice with acute lung infection. Here we report that co-infection with MNV increases survival of mice with Pseudomonas aeruginosa acute lung injury and decreases in vivo production of pro-inflammatory cytokines. Our results suggest that MNV infection can deeply modify the parameters studied in conventional models of infection and lead to false conclusions in experimental models.

  10. Eliminating Murine Norovirus by Cross-Fostering

    PubMed Central

    Buxbaum, Laurence U.; DeRitis, Pierina C.; Chu, Niansheng; Conti, Pierre A.

    2011-01-01

    Murine norovirus (MNV) is a newly discovered and extremely prevalent pathogen of laboratory mouse colonies. MNV causes severe disease in some immunocompromised mouse strains and can cause persistent infections even in immunocompetent mice. Despite the fact that immunocompetent mice are generally asymptomatic, the possibility that MNV infection might alter immune responses makes its eradication a potentially useful goal for many facilities. Initial attempts by others to use a strategy of testing and culling were unsuccessful, whereas complete depopulation and facility decontamination was successful. However, these measures may be impractical, and finding less drastic approaches seemed prudent. Based on a report that cross-fostering of pups from MNV-positive mothers to MNV-negative ones could be successful in experimental MNV infection, we undertook a comprehensive fostering program using Swiss Webster mothers, careful sanitary measures, and fecal PCR testing to eradicate the virus from a mouse colony recently infected with MNV. We successfully decontaminated 17 of 18 (94%) litters and managed to prevent spread when a new MNV-infected mouse strain entered quarantine at our facility. These results suggest that cross-fostering, when performed in a setting of excellent sanitary procedures, may be practical for the large number of mouse facilities in which MNV is endemic. PMID:21838978

  11. Enhanced hygiene measures and norovirus transmission during an outbreak.

    PubMed

    Heijne, Janneke C M; Teunis, Peter; Morroy, Gabriella; Wijkmans, Clementine; Oostveen, Sandy; Duizer, Erwin; Kretzschmar, Mirjam; Wallinga, Jacco

    2009-01-01

    Control of norovirus outbreaks relies on enhanced hygiene measures, such as handwashing, surface cleaning, using disposable paper towels, and using separate toilets for sick and well persons. However, little is known about their effectiveness in limiting further spread of norovirus infections. We analyzed norovirus outbreaks in 7 camps at an international scouting jamboree in the Netherlands during 2004. Implementation of hygiene measures coincided with an 84.8% (95% predictive interval 81.2%-86.6%) reduction in reproduction number. This reduction was unexpectedly large but still below the reduction needed to contain a norovirus outbreak. Even more stringent control measures are required to break the chain of transmission of norovirus.

  12. Plaque assay for murine norovirus.

    PubMed

    Gonzalez-Hernandez, Mariam B; Bragazzi Cunha, Juliana; Wobus, Christiane E

    2012-08-22

    Murine norovirus (MNV) is the only member of the Norovirus genus that efficiently grows in tissue culture. Cell lysis and cytopathic effect (CPE) are observed during MNV-1 infection of murine dendritic cells or macrophages. This property of MNV-1 can be used to quantify the number of infectious particles in a given sample by performing a plaque assay. The plaque assay relies on the ability of MNV-1 to lyse cells and to form holes in a confluent cell monolayer, which are called plaques. Multiple techniques can be used to detect viral infections in tissue culture, harvested tissue, clinical, and environmental samples, but not all measure the number of infectious particles (e.g. qRT-PCR). One way to quantify infectious viral particles is to perform a plaque assay, which will be described in detail below. A variation on the MNV plaque assay is the fluorescent focus assay, where MNV antigen is immunostained in cell monolayers. This assay can be faster, since viral antigen expression precedes plaque formation. It is also useful for titrating viruses unable to form plaques. However, the fluorescent focus assay requires additional resources beyond those of the plaque assay, such as antibodies and a microscope to count focus-forming units. Infectious MNV can also be quantified by determining the 50% Tissue Culture Infective Dose (TCID50). This assay measures the amount of virus required to produce CPE in 50% of inoculated tissue culture cells by endpoint titration. However, its limit of detection is higher compared to a plaque assay. In this article, we describe a plaque assay protocol that can be used to effectively determine the number of infectious MNV particles present in biological or environmental samples. This method is based on the preparation of 10-fold serial dilutions of MNV-containing samples, which are used to inoculate a monolayer of permissive cells (RAW 264.7 murine macrophage cells). Virus is allowed to attach to the cell monolayer for a given period of

  13. Mechanisms of antiviral action of plant antimicrobials against murine norovirus.

    PubMed

    Gilling, Damian H; Kitajima, Masaaki; Torrey, Jason R; Bright, Kelly R

    2014-08-01

    Numerous plant compounds have antibacterial or antiviral properties; however, limited research has been conducted with nonenveloped viruses. The efficacies of allspice oil, lemongrass oil, and citral were evaluated against the nonenveloped murine norovirus (MNV), a human norovirus surrogate. The antiviral mechanisms of action were also examined using an RNase I protection assay, a host cell binding assay, and transmission electron microscopy. All three antimicrobials produced significant reductions (P ≤ 0.05) in viral infectivity within 6 h of exposure (0.90 log10 to 1.88 log10). After 24 h, the reductions were 2.74, 3.00, and 3.41 log10 for lemongrass oil, citral, and allspice oil, respectively. The antiviral effect of allspice oil was both time and concentration dependent; the effects of lemongrass oil and citral were time dependent. Based on the RNase I assay, allspice oil appeared to act directly upon the viral capsid and RNA. The capsids enlarged from ≤ 35 nm to up to 75 nm following treatment. MNV adsorption to host cells was not significantly affected. Alternatively, the capsid remained intact following exposure to lemongrass oil and citral, which appeared to coat the capsid, causing nonspecific and nonproductive binding to host cells that did not lead to successful infection. Such contrasting effects between allspice oil and both lemongrass oil and citral suggest that though different plant compounds may yield similar reductions in virus infectivity, the mechanisms of inactivation may be highly varied and specific to the antimicrobial. This study demonstrates the antiviral properties of allspice oil, lemongrass oil, and citral against MNV and thus indicates their potential as natural food and surface sanitizers to control noroviruses. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  14. Mechanisms of Antiviral Action of Plant Antimicrobials against Murine Norovirus

    PubMed Central

    Gilling, Damian H.; Kitajima, Masaaki; Torrey, Jason R.

    2014-01-01

    Numerous plant compounds have antibacterial or antiviral properties; however, limited research has been conducted with nonenveloped viruses. The efficacies of allspice oil, lemongrass oil, and citral were evaluated against the nonenveloped murine norovirus (MNV), a human norovirus surrogate. The antiviral mechanisms of action were also examined using an RNase I protection assay, a host cell binding assay, and transmission electron microscopy. All three antimicrobials produced significant reductions (P ≤ 0.05) in viral infectivity within 6 h of exposure (0.90 log10 to 1.88 log10). After 24 h, the reductions were 2.74, 3.00, and 3.41 log10 for lemongrass oil, citral, and allspice oil, respectively. The antiviral effect of allspice oil was both time and concentration dependent; the effects of lemongrass oil and citral were time dependent. Based on the RNase I assay, allspice oil appeared to act directly upon the viral capsid and RNA. The capsids enlarged from ≤35 nm to up to 75 nm following treatment. MNV adsorption to host cells was not significantly affected. Alternatively, the capsid remained intact following exposure to lemongrass oil and citral, which appeared to coat the capsid, causing nonspecific and nonproductive binding to host cells that did not lead to successful infection. Such contrasting effects between allspice oil and both lemongrass oil and citral suggest that though different plant compounds may yield similar reductions in virus infectivity, the mechanisms of inactivation may be highly varied and specific to the antimicrobial. This study demonstrates the antiviral properties of allspice oil, lemongrass oil, and citral against MNV and thus indicates their potential as natural food and surface sanitizers to control noroviruses. PMID:24907316

  15. A norovirus outbreak related to contaminated surfaces.

    PubMed

    Repp, Kimberly K; Hostetler, Trevor P; Keene, William E

    2013-07-15

    We investigated an outbreak of norovirus infection affecting 12 of 16 auto dealership employees (75%) subsequent to a staff meeting. Take-out sandwiches initially seemed the likely source, but a cohort study found no association between illness and food consumption. Employees reported seeing a toddler with diarrhea in a dealership restroom shortly before the luncheon. Indistinguishable norovirus was isolated from employees and the child (genotype GII6.C) and from a diaper-changing station in the restroom (genogroup GII). Counterintuitively, this point-source outbreak following a meal was caused by environmental exposures, not food. Environmental exposures should be considered even in routine outbreak investigations.

  16. The sweet quartet: Binding of fucose to the norovirus capsid.

    PubMed

    Koromyslova, Anna D; Leuthold, Mila M; Bowler, Matthew W; Hansman, Grant S

    2015-09-01

    Human noroviruses bind histo-blood group antigens (HBGAs) and this interaction is thought to be important for an infection. We identified two additional fucose-binding pockets (termed fucose-3/4 sites) on a genogroup II human (GII.10) norovirus-protruding (P) dimer using X-ray crystallography. Fucose-3/4 sites were located between two previously determined HBGA binding pockets (termed fucose-1/2 sites). We found that four fucose molecules were capable of binding altogether at fucose-1/2/3/4 sites on the P dimer, though the fucose molecules bound in a dose-dependent and step-wise manner. We also showed that HBGA B-trisaccharide molecules bound in a similar way at the fucose-1/2 sites. Interestingly, we discovered that the monomers of the P dimer were asymmetrical in an unliganded state and when a single B-trisaccharide molecule bound, but were symmetrical when two B-trisaccharide molecules bound. We postulate that the symmetrical dimers might favor HBGA binding interactions at fucose-1/2 sites.

  17. Serological Correlates of Protection against a GII.4 Norovirus

    PubMed Central

    Bernstein, David I.; Lyon, G. Marshall; Treanor, John J.; Al-Ibrahim, Mohamed S.; Graham, David Y.; Vinjé, Jan; Jiang, Xi; Gregoricus, Nicole; Frenck, Robert W.; Moe, Christine L.; Chen, Wilbur H.; Ferreira, Jennifer; Barrett, Jill; Opekun, Antone R.; Estes, Mary K.; Borkowski, Astrid; Baehner, Frank; Goodwin, Robert; Edmonds, Anthony; Mendelman, Paul M.

    2015-01-01

    Noroviruses are the leading cause of acute gastroenteritis worldwide, and norovirus vaccine prevention strategies are under evaluation. The immunogenicity of two doses of bivalent genogroup 1 genotype 1 (GI.1)/GII.4 (50 μg of virus-like particles [VLPs] of each strain adjuvanted with aluminum hydroxide and 3-O-desacyl-4′monophosphoryl lipid A [MPL]) norovirus vaccine administered to healthy adults in a phase 1/2 double-blind placebo-controlled trial was determined using virus-specific serum total antibody enzyme-linked immunosorbent assay (ELISA), IgG, IgA, and histoblood group antigen (HBGA)-blocking assays. Trial participants subsequently received an oral live virus challenge with a GII.4 strain, and the vaccine efficacy results were reported previously (D. I. Bernstein et al., J Infect Dis 211:870–878, 2014, doi:10.1093/infdis/jiu497). This report assesses the impact of prechallenge serum antibody levels on infection and illness outcomes. Serum antibody responses were observed in vaccine recipients by all antibody assays, with first-dose seroresponse frequencies ranging from 88 to 100% for the GI.1 antigen and from 69 to 84% for the GII.4 antigen. There was little increase in antibody levels after the second vaccine dose. Among the subjects receiving the placebo, higher prechallenge serum anti-GII.4 HBGA-blocking and IgA antibody levels, but not IgG or total antibody levels, were associated with a lower frequency of virus infection and associated illness. Notably, some placebo subjects without measurable serum antibody levels prechallenge did not become infected after norovirus challenge. In vaccinees, anti-GII.4 HBGA-blocking antibody levels of >1:500 were associated with a lower frequency of moderate-to-severe vomiting or diarrheal illness. In this study, prechallenge serum HBGA antibody titers correlated with protection in subjects receiving the placebo; however, other factors may impact the likelihood of infection and illness after virus exposure. (This

  18. Serological Correlates of Protection against a GII.4 Norovirus.

    PubMed

    Atmar, Robert L; Bernstein, David I; Lyon, G Marshall; Treanor, John J; Al-Ibrahim, Mohamed S; Graham, David Y; Vinjé, Jan; Jiang, Xi; Gregoricus, Nicole; Frenck, Robert W; Moe, Christine L; Chen, Wilbur H; Ferreira, Jennifer; Barrett, Jill; Opekun, Antone R; Estes, Mary K; Borkowski, Astrid; Baehner, Frank; Goodwin, Robert; Edmonds, Anthony; Mendelman, Paul M

    2015-08-01

    Noroviruses are the leading cause of acute gastroenteritis worldwide, and norovirus vaccine prevention strategies are under evaluation. The immunogenicity of two doses of bivalent genogroup 1 genotype 1 (GI.1)/GII.4 (50 μg of virus-like particles [VLPs] of each strain adjuvanted with aluminum hydroxide and 3-O-desacyl-4'monophosphoryl lipid A [MPL]) norovirus vaccine administered to healthy adults in a phase 1/2 double-blind placebo-controlled trial was determined using virus-specific serum total antibody enzyme-linked immunosorbent assay (ELISA), IgG, IgA, and histoblood group antigen (HBGA)-blocking assays. Trial participants subsequently received an oral live virus challenge with a GII.4 strain, and the vaccine efficacy results were reported previously (D. I. Bernstein et al., J Infect Dis 211:870-878, 2014, doi:10.1093/infdis/jiu497). This report assesses the impact of prechallenge serum antibody levels on infection and illness outcomes. Serum antibody responses were observed in vaccine recipients by all antibody assays, with first-dose seroresponse frequencies ranging from 88 to 100% for the GI.1 antigen and from 69 to 84% for the GII.4 antigen. There was little increase in antibody levels after the second vaccine dose. Among the subjects receiving the placebo, higher prechallenge serum anti-GII.4 HBGA-blocking and IgA antibody levels, but not IgG or total antibody levels, were associated with a lower frequency of virus infection and associated illness. Notably, some placebo subjects without measurable serum antibody levels prechallenge did not become infected after norovirus challenge. In vaccinees, anti-GII.4 HBGA-blocking antibody levels of >1:500 were associated with a lower frequency of moderate-to-severe vomiting or diarrheal illness. In this study, prechallenge serum HBGA antibody titers correlated with protection in subjects receiving the placebo; however, other factors may impact the likelihood of infection and illness after virus exposure. (This

  19. The Effect of Heat and Free Chlorine Treatments on the Surface Properties of Murine Norovirus.

    PubMed

    Brié, Adrien; Razafimahefa, Ravo; Loutreul, Julie; Robert, Aurélie; Gantzer, Christophe; Boudaud, Nicolas; Bertrand, Isabelle

    2017-06-01

    Heat and free chlorine are among the most efficient and commonly used treatments to inactivate enteric viruses, but their global inactivation mechanisms have not been elucidated yet. These treatments have been shown to affect at least the capsid proteins of viruses and thus may affect the surface properties (i.e. electrostatic charge and hydrophobicity) of such particles. Our aim was to study the effects of heat and free chlorine on surface properties for a murine norovirus chosen as surrogate for human norovirus. No changes in the surface properties were observed with our methods for murine norovirus exposed to free chlorine. Only the heat treatment led to major changes in the surface properties of the virus with the expression of hydrophobic domains at the surface of the particles after exposure to a temperature of 55 °C. No modification of the expression of hydrophobic domains occurred after exposure to 60 °C, and the low hydrophobic state exhibited by infectious and inactivated particles after exposure to 60 °C appeared to be irreversible for inactivated particles only, which may provide a means to discriminate infectious from inactivated murine noroviruses. When exposed to a temperature of 72 °C or to free chlorine at a concentration of 50 mg/L, the genome became available for RNases.

  20. Development of rapid hemocyte-based extraction methods for detection of hepatitis A virus and murine norovirus in contaminated oysters

    USDA-ARS?s Scientific Manuscript database

    The human enteric pathogens, hepatitis A virus and human norovirus, have been shown to contaminate molluscan shellfish and cause foodborne disease in consumers. Rapid viral extraction methods are needed to replace current time consuming methods, which use whole oysters or dissected tissues. In our ...

  1. Identification of Genogroup I and Genogroup II Broadly Reactive Epitopes on the Norovirus Capsid

    PubMed Central

    Parker, Tracy Dewese; Kitamoto, Noritoshi; Tanaka, Tomoyuki; Hutson, Anne M.; Estes, Mary K.

    2005-01-01

    Norwalk virus, a member of the family Caliciviridae, is an important cause of acute epidemic nonbacterial gastroenteritis. Norwalk and related viruses are classified in a separate genus of Caliciviridae called Norovirus, which is comprised of at least three genogroups based on sequence differences. Many of the currently available immunologic reagents used to study these viruses are type specific, which limits the identification of antigenically distinct viruses in detection assays. Identification of type-specific and cross-reactive epitopes is essential for designing broadly cross-reactive diagnostic assays and dissecting the immune response to calicivirus infection. To address this, we have mapped the epitopes on the norovirus capsid protein for both a genogroup I-cross-reactive monoclonal antibody and a genogroup II-cross-reactive monoclonal antibody by use of norovirus deletion and point mutants. The epitopes for both monoclonal antibodies mapped to the C-terminal P1 subdomain of the capsid protein. Although the genogroup I-cross-reactive monoclonal antibody was previously believed to recognize a linear epitope, our results indicate that a conformational component of the epitope explains the monoclonal antibody's genogroup specificity. Identification of the epitopes for these monoclonal antibodies is of significance, as they are components in a commercially available norovirus-diagnostic enzyme-linked immunosorbent assay. PMID:15919896

  2. Pediatric Norovirus Diarrhea in Nicaragua▿

    PubMed Central

    Bucardo, Filemon; Nordgren, Johan; Carlsson, Beatrice; Paniagua, Margarita; Lindgren, Per-Eric; Espinoza, Felix; Svensson, Lennart

    2008-01-01

    Information about norovirus (NoV) infections in Central America is limited. Through a passive community and hospital pediatric diarrhea surveillance program, a total of 542 stool samples were collected between March 2005 and February 2006 in León, Nicaragua. NoV was detected in 12% (65/542) of the children; of these, 11% (45/409) were in the community and 15% (20/133) were in the hospital, with most strains (88%) belonging to genogroup II. NoV infections were age and gender associated, with children of <2 years of age (P < 0.05) and girls (P < 0.05) being most affected. Breast-feeding did not reduce the number of NoV infections. An important proportion (57%) of NoV-infected children were coinfected with diarrheagenic Escherichia coli. A significant proportion (18/31) of NoV-positive children with dehydration required intravenous rehydration. Nucleotide sequence analysis (38/65) of the N-terminal and shell region in the capsid gene revealed that at least six genotypes (GI.4, GII.2, GII.4, GII.7, GII.17, and a potentially novel cluster termed “GII.18-Nica”) circulated during the study period, with GII.4 virus being predominant (26/38). The majority (20/26) of those GII.4 strains shared high nucleotide homology (99%) with the globally emerging Hunter strain. The mean viral load was approximately 15-fold higher in children infected with GII.4 virus than in those infected with other G.II viruses, with the highest viral load observed for the group of children infected with GII.4 and requiring intravenous rehydration. This study, the first of its type from a Central American country, suggests that NoV is an important etiological agent of acute diarrhea among children of <2 years of age in Nicaragua. PMID:18562593

  3. Global Economic Burden of Norovirus Gastroenteritis

    PubMed Central

    Bartsch, Sarah M.; Lopman, Benjamin A.; Ozawa, Sachiko; Hall, Aron J.; Lee, Bruce Y.

    2016-01-01

    Background Despite accounting for approximately one fifth of all acute gastroenteritis illnesses, norovirus has received comparatively less attention than other infectious pathogens. With several candidate vaccines under development, characterizing the global economic burden of norovirus could help funders, policy makers, public health officials, and product developers determine how much attention and resources to allocate to advancing these technologies to prevent and control norovirus. Methods We developed a computational simulation model to estimate the economic burden of norovirus in every country/area (233 total) stratified by WHO region and globally, from the health system and societal perspectives. We considered direct costs of illness (e.g., clinic visits and hospitalization) and productivity losses. Results Globally, norovirus resulted in a total of $4.2 billion (95% UI: $3.2–5.7 billion) in direct health system costs and $60.3 billion (95% UI: $44.4–83.4 billion) in societal costs per year. Disease amongst children <5 years cost society $39.8 billion, compared to $20.4 billion for all other age groups combined. Costs per norovirus illness varied by both region and age and was highest among adults ≥55 years. Productivity losses represented 84–99% of total costs varying by region. While low and middle income countries and high income countries had similar disease incidence (10,148 vs. 9,935 illness per 100,000 persons), high income countries generated 62% of global health system costs. In sensitivity analysis, the probability of hospitalization had the largest impact on health system cost estimates ($2.8 billion globally, assuming no hospitalization costs), while the probability of missing productive days had the largest impact on societal cost estimates ($35.9 billion globally, with a 25% probability of missing productive days). Conclusions The total economic burden is greatest in young children but the highest cost per illness is among older age

  4. Seroepidemiology of Norovirus-Associated Travelers’ Diarrhea

    PubMed Central

    Ajami, Nadim J.; Kavanagh, Owen V.; Ramani, Sasirekha; Crawford, Sue E.; Atmar, Robert L.; Jiang, Zhi-Dong; Okhuysen, Pablo C.; Estes, Mary K.; DuPont, Herbert L.

    2014-01-01

    Background Noroviruses (NoVs) are the most common cause of epidemic gastroenteritis, responsible for at least 50% of all gastroenteritis outbreaks worldwide and were recently identified as a leading cause of travelers’ diarrhea (TD) in U.S. and European travelers to Mexico, Guatemala and India. Methods Serum and diarrheic stool samples were collected from 75 US student travelers to Cuernavaca, Mexico, who developed TD. NoV RNA was detected in acute diarrheic stool samples using RT-PCR. Serology assays were performed using GI.1 Norwalk virus (NV) and GII.4 Houston virus (HOV) virus-like particles (VLP) to measure serum levels of IgA and IgG by Dissociation-Enhanced Lanthanide Fluorescent Immunoassay (DELFIA); serum IgM was measured by capture ELISA, and the 50% antibody blocking titer (BT50) was determined by a carbohydrate-blocking assay. Results NoV infection was identified in 12 (16%; 9 GI-NoV and 3 GII-NoV) of 75 travelers by either RT-PCR or ≥4-fold rise in antibody titer. Significantly more individuals had detectable pre-existing IgA antibodies against HOV (62/75, 83%) than against NV (49/75, 65%) (p=0.025) VLPs. A significant difference was observed between NV- and HOV-specific preexisting IgA antibody levels (p=0.0037), IgG (p=0.003) and BT50 (p=<0.0001). None of the NoV-infected TD travelers had BT50 >200, a level that has been described previously as a possible correlate of protection. Conclusions We found that GI-NoVs are commonly associated with TD cases identified in U.S. adults traveling to Mexico, and seroprevalence rates and geometric mean antibody levels to a GI-NoV were lower than to a GII-NoV strain. PMID:24383649

  5. Application of a Receptor-Binding Capture Quantitative Reverse Transcription-PCR Assay To Concentrate Human Norovirus from Sewage and To Study the Distribution and Stability of the Virus

    PubMed Central

    Yang, David; Pan, Liangwen; Mandrell, Robert

    2012-01-01

    Water is an important route for human norovirus (HuNoV) transmission. Using magnetic beads conjugated with blood group-like antigens (HuNoV receptors), we developed a simple and rapid receptor-binding capture and magnetic sequestration (RBCMS) method and compared it to the existing negatively charged membrane absorption/elution (NCMAE) method for concentrating HuNoV from sewage effluent. RBCMS required 6-fold-less sample volume than the NCMAE method and also resulted in a significantly higher yield of HuNoV. The NCMAE and RBCMS concentrations of genogroup I (GI) HuNoV measured by quantitative reverse transcription-PCR (qRT-PCR) resulted in average threshold cycle (CT) values of 34.68 (8.68 copies, 252-fold concentration) versus 34.07 (13.05 copies, 477-fold concentration), respectively; the NCMAE and RBCMS concentrations of genogroup II (GII) HuNoV were measured as average CT values of 33.32 (24.7 copies, 239-fold concentration) versus 32.38 (46.9 copies, 333-fold concentration), respectively. The specificity of qRT-PCR was confirmed by traditional RT-PCR and an RNase I protection assay. The qRT-PCR signal from RBCMS-concentrated HuNoV treated with RNase I indicated that it was from encapsidated RNA and, probably, viable virus. In contrast, the qRT-PCR signal from NCMAE-concentrated HuNoV was not protected from RNase I and, likely, degradation. Both GI and GII HuNoV were detected from sewage effluent samples collected between April and July with average concentrations of 7.8 × 103 genomic copies per liter (gc/liter) and 4.3 × 104 gc/liter, respectively. No GI and <2% GII HuNoV were detected in sewage samples stored at room temperature for 4 weeks. We conclude that RBCMS requires less sample volume, has better recovery and sensitivity, and is faster than NCMAE for detection of HuNoV in sewage. PMID:22101044

  6. Recurring norovirus transmission on an airplane.

    PubMed

    Thornley, Craig N; Emslie, Nicola A; Sprott, Tim W; Greening, Gail E; Rapana, Jackie P

    2011-09-01

    Previously reported outbreaks of norovirus gastroenteritis associated with aircraft have been limited to transmission during a single flight sector. During October 2009, an outbreak of diarrhea and vomiting occurred among different groups of flight attendants who had worked on separate flight sectors on the same airplane. We investigated the cause of the outbreak and whether the illnesses were attributable to work on the airplane. Information was obtained from flight attendants on demographic characteristics, symptoms, and possible transmission risk factors. Case patients were defined as flight attendants with diarrhea or vomiting <51 hours after the end of their first flight sector on the airplane during 13-18 October 2009. Stool samples were tested for norovirus RNA. A passenger had vomited on the Boeing 777-200 airplane on the 13 October flight sector. Sixty-three (82%) of 77 flight attendants who worked on the airplane during 13-18 October provided information, and 27 (43%) met the case definition. The attack rate among flight attendants decreased significantly over successive flight sectors from 13 October onward (P < .001). Working as a supervisor was independently associated with development of illness (adjusted odds ratio, 5.8; 95% confidence interval, 1.3-25.6). Norovirus genotype GI.6 was detected in stool samples from 2 case patients who worked on different flight sectors. Sustained transmission of norovirus is likely to have occurred because of exposures on this airplane during successive flight sectors. Airlines should make provision for adequate disinfection of airplanes with use of products effective against norovirus and other common infectious agents after vomiting has occurred.

  7. Infants' Responses to Real Humans and Representations of Humans

    ERIC Educational Resources Information Center

    Heron, Michelle; Slaughter, Virginia

    2010-01-01

    Infants' responses to typical and scrambled human body shapes were assessed in relation to the realism of the human body stimuli presented. In four separate experiments, infants were familiarized to typical human bodies and then shown a series of scrambled human bodies on the test. Looking behaviour was assessed in response to a range of different…

  8. Infants' Responses to Real Humans and Representations of Humans

    ERIC Educational Resources Information Center

    Heron, Michelle; Slaughter, Virginia

    2010-01-01

    Infants' responses to typical and scrambled human body shapes were assessed in relation to the realism of the human body stimuli presented. In four separate experiments, infants were familiarized to typical human bodies and then shown a series of scrambled human bodies on the test. Looking behaviour was assessed in response to a range of different…

  9. The transmissibility of noroviruses: Statistical modeling of outbreak events with known route of transmission in Japan

    PubMed Central

    Matsuyama, Ryota; Miura, Fuminari

    2017-01-01

    In Japan, the fraction of norovirus outbreaks attributable to human-to-human transmission has increased with time, and the timing of the increased fraction has coincided with the increase in the observed fraction of genogroup II genotype 4 (GII.4). The present study aimed to estimate the time-dependent changes in the transmissibility of noroviruses. The effective reproduction number (Ry), for year y, was estimated by analyzing the time series surveillance data for outbreak events from 2000 to 2016. Ry was estimated by using the fraction of outbreak events that were attributable to human-to-human transmission and by employing three different statistical models that are considered to mechanistically capture the possible data-generating process in different ways. The Ry estimates ranged from 0.14 to 4.15 in value, revealing an overall increasing trend (p<0.05 for all three models). The proportion of outbreaks caused by GII and GII.4 viruses among the total events also increased with time, and positive correlations were identified between transmissibility and these proportions. Parametric modeling of Ry indicated that the time-dependent patterns of Ry were better described by a step function plus linear trend rather than the step function alone that reflects the widespread use of reverse transcriptase PCR (RT-PCR) in and after 2007 for laboratory diagnosis. Accordingly, we conclude that norovirus transmissibility has increased over the past 16 years in Japan. The change is at least partially explained by the time-dependent domination of the contagious GII genogroup (e.g., GII.4), indicating that noroviruses better fitted to humans have selectively caused the human-to-human transmissions, thereby altering the epidemiology of this pathogen. PMID:28296972

  10. Detecting the Norovirus Season in Sweden Using Search Engine Data – Meeting the Needs of Hospital Infection Control Teams

    PubMed Central

    Edelstein, Michael; Wallensten, Anders; Zetterqvist, Inga; Hulth, Anette

    2014-01-01

    Norovirus outbreaks severely disrupt healthcare systems. We evaluated whether Websök, an internet-based surveillance system using search engine data, improved norovirus surveillance and response in Sweden. We compared Websök users' characteristics with the general population, cross-correlated weekly Websök searches with laboratory notifications between 2006 and 2013, compared the time Websök and laboratory data crossed the epidemic threshold and surveyed infection control teams about their perception and use of Websök. Users of Websök were not representative of the general population. Websök correlated with laboratory data (b = 0.88-0.89) and gave an earlier signal to the onset of the norovirus season compared with laboratory-based surveillance. 17/21 (81%) infection control teams answered the survey, of which 11 (65%) believed Websök could help with infection control plans. Websök is a low-resource, easily replicable system that detects the norovirus season as reliably as laboratory data, but earlier. Using Websök in routine surveillance can help infection control teams prepare for the yearly norovirus season. PMID:24955857

  11. Prevalence of Rotavirus Genogroup A and Norovirus Genogroup II in Bassaseachic Falls National Park Surface Waters in Chihuahua, Mexico

    PubMed Central

    Delgado-Gardea, Ma. Carmen E.; Tamez-Guerra, Patricia; Gomez-Flores, Ricardo; Mendieta-Mendoza, Aurora; Zavala-Díaz de la Serna, Francisco Javier; Contreras-Cordero, Juan Francisco; Erosa-de la Vega, Gilberto; Pérez-Recoder, María Concepción; Sánchez-Ramírez, Blanca; González-Horta, Carmen; Infante-Ramírez, Rocío

    2017-01-01

    In areas lacking potable water treatment, drinking contaminated water may represent a public health threat. In addition to enteropathogenic bacteria and parasites, fecal contamination in water environments is associated with the transmission of enteric viruses and other causal agents of infectious disease. Rotavirus and norovirus are the main enteric viral agents responsible for diarrheic outbreaks. The aim of the present study was to detect seasonal variation of rotavirus and norovirus in the surface water at Bassaseachic Falls National Park during 2013. Rivers and streams within and nearby this park were sampled once in each season during 2013. Viral concentration was carried out by a handmade filtration equipment, using a commercial electropositive membrane coupled with the virus absortion elution technique (VIRADEL©). Detection of rotavirus and norovirus was performed by SYBR Green reverse transcription-real time polymerase chain reaction (SYBR GREEN© RT-qPCR) analyses. Norovirus genogroup II was detected in samples collected in June and October 2013. In the case of rotavirus, genogroup A was detected in March and June. The presence of rotavirus and norovirus was related to viral acute diarrhea in children less than five years of age, who were inhabiting the sampled areas. This may indicates that the contaminated water was potentially a risk factor for regional diarrheic outbreaks. PMID:28475152

  12. Prevalence of Rotavirus Genogroup A and Norovirus Genogroup II in Bassaseachic Falls National Park Surface Waters in Chihuahua, Mexico.

    PubMed

    Delgado-Gardea, Ma Carmen E; Tamez-Guerra, Patricia; Gomez-Flores, Ricardo; Mendieta-Mendoza, Aurora; Zavala-Díaz de la Serna, Francisco Javier; Contreras-Cordero, Juan Francisco; Erosa-de la Vega, Gilberto; Pérez-Recoder, María Concepción; Sánchez-Ramírez, Blanca; González-Horta, Carmen; Infante-Ramírez, Rocío

    2017-05-05

    In areas lacking potable water treatment, drinking contaminated water may represent a public health threat. In addition to enteropathogenic bacteria and parasites, fecal contamination in water environments is associated with the transmission of enteric viruses and other causal agents of infectious disease. Rotavirus and norovirus are the main enteric viral agents responsible for diarrheic outbreaks. The aim of the present study was to detect seasonal variation of rotavirus and norovirus in the surface water at Bassaseachic Falls National Park during 2013. Rivers and streams within and nearby this park were sampled once in each season during 2013. Viral concentration was carried out by a handmade filtration equipment, using a commercial electropositive membrane coupled with the virus absortion elution technique (VIRADEL©). Detection of rotavirus and norovirus was performed by SYBR Green reverse transcription-real time polymerase chain reaction (SYBR GREEN© RT-qPCR) analyses. Norovirus genogroup II was detected in samples collected in June and October 2013. In the case of rotavirus, genogroup A was detected in March and June. The presence of rotavirus and norovirus was related to viral acute diarrhea in children less than five years of age, who were inhabiting the sampled areas. This may indicates that the contaminated water was potentially a risk factor for regional diarrheic outbreaks.

  13. Detecting the norovirus season in Sweden using search engine data--meeting the needs of hospital infection control teams.

    PubMed

    Edelstein, Michael; Wallensten, Anders; Zetterqvist, Inga; Hulth, Anette

    2014-01-01

    Norovirus outbreaks severely disrupt healthcare systems. We evaluated whether Websök, an internet-based surveillance system using search engine data, improved norovirus surveillance and response in Sweden. We compared Websök users' characteristics with the general population, cross-correlated weekly Websök searches with laboratory notifications between 2006 and 2013, compared the time Websök and laboratory data crossed the epidemic threshold and surveyed infection control teams about their perception and use of Websök. Users of Websök were not representative of the general population. Websök correlated with laboratory data (b = 0.88-0.89) and gave an earlier signal to the onset of the norovirus season compared with laboratory-based surveillance. 17/21 (81%) infection control teams answered the survey, of which 11 (65%) believed Websök could help with infection control plans. Websök is a low-resource, easily replicable system that detects the norovirus season as reliably as laboratory data, but earlier. Using Websök in routine surveillance can help infection control teams prepare for the yearly norovirus season.

  14. Towards the development of a combined Norovirus and sediment transport model for coastal waters

    NASA Astrophysics Data System (ADS)

    Barry, K.; O'Kane, J. P. J.

    2009-04-01

    Sewage effluent in coastal waters used for oyster culture poses a risk to human health. The primary pathogen in outbreaks of gastroenteritis following consumption of raw oysters is the Norovirus or "winter vomiting bug". The Norovirus is a highly infectious RNA virus of the Caliciviridae taxonomic family. It has a long survival time in coastal waters (T90 = 30 days in winter). Oysters selectively concentrate Norovirus in their digestive ducts. The virus cannot be removed by conventional depuration. The primary goal of the research is to quantify the risk of Norovirus infection in coastal waters through physically-based high-resolution numerical modelling. Cork Harbour and Clew Bay in Ireland provide case studies for the research. The models simulate a number of complex physical, chemical and biological processes which influence the transport and decay of the virus as well as its bioaccumulation in oyster tissue. The current phase of the research is concerned with the adsorption of the virus to suspended sediment in the water column. Adsorbed viruses may be taken out of the water column when sedimentation occurs and, subsequently, be added to it with resuspension of the bed sediment. Preliminary simulations of the Norovirus-sediment model indicate that suspended sediment can influence the transport of the virus in coastal waters when a high sediment-water partitioning coefficient is used and the model is run under calm environmental conditions. In this instance a certain fraction of the adsorbed viruses are taken out of the water column by sedimentation and end up locked in the bed sediment. Subsequently, under storm conditions, a large number of viruses in the bed are released into the water column by erosion of the bed and a risk of contamination occurs at a time different to when the viruses were initially released into the body of water.

  15. Immunogenetic Mechanisms Driving Norovirus GII.4 Antigenic Variation

    PubMed Central

    Donaldson, Eric F.; Corti, Davide; Swanstrom, Jesica; Debbink, Kari; Lanzavecchia, Antonio; Baric, Ralph S.

    2012-01-01

    Noroviruses are the principal cause of epidemic gastroenteritis worldwide with GII.4 strains accounting for 80% of infections. The major capsid protein of GII.4 strains is evolving rapidly, resulting in new epidemic strains with altered antigenic potentials. To test if antigenic drift may contribute to GII.4 persistence, human memory B cells were immortalized and the resulting human monoclonal antibodies (mAbs) characterized for reactivity to a panel of time-ordered GII.4 virus-like particles (VLPs). Reflecting the complex exposure history of the volunteer, human anti-GII.4 mAbs grouped into three VLP reactivity patterns; ancestral (1987–1997), contemporary (2004–2009), and broad (1987–2009). NVB 114 reacted exclusively to the earliest GII.4 VLPs by EIA and blockade. NVB 97 specifically bound and blocked only contemporary GII.4 VLPs, while NBV 111 and 43.9 exclusively reacted with and blocked variants of the GII.4.2006 Minerva strain. Three mAbs had broad GII.4 reactivity. Two, NVB 37.10 and 61.3, also detected other genogroup II VLPs by EIA but did not block any VLP interactions with carbohydrate ligands. NVB 71.4 cross-neutralized the panel of time-ordered GII.4 VLPs, as measured by VLP-carbohydrate blockade assays. Using mutant VLPs designed to alter predicted antigenic epitopes, two evolving, GII.4-specific, blockade epitopes were mapped. Amino acids 294–298 and 368–372 were required for binding NVB 114, 111 and 43.9 mAbs. Amino acids 393–395 were essential for binding NVB 97, supporting earlier correlations between antibody blockade escape and carbohydrate binding variation. These data inform VLP vaccine design, provide a strategy for expanding the cross-blockade potential of chimeric VLP vaccines, and identify an antibody with broadly neutralizing therapeutic potential for the treatment of human disease. Moreover, these data support the hypothesis that GII.4 norovirus evolution is heavily influenced by antigenic variation of neutralizing epitopes

  16. Identification and Characterization of Single-Chain Antibodies that Specifically Bind GI Noroviruses.

    PubMed

    Hurwitz, Amy M; Huang, Wanzhi; Kou, Baijun; Estes, Mary K; Atmar, Robert L; Palzkill, Timothy

    2017-01-01

    Norovirus infections commonly lead to outbreaks of acute gastroenteritis and spread quickly, resulting in many health and economic challenges prior to diagnosis. Rapid and reliable diagnostic tests are therefore essential to identify infections and to guide the appropriate clinical responses at the point-of-care. Existing tools, including RT-PCR and enzyme immunoassays, pose several limitations based on the significant time, equipment and expertise required to elicit results. Immunochromatographic assays available for use at the point-of-care have poor sensitivity and specificity, especially for genogroup I noroviruses, thus requiring confirmation of results with more sensitive testing methods. Therefore, there is a clear need for novel reagents to help achieve quick and reliable results. In this study, we have identified two novel single-chain antibodies (scFvs)-named NJT-R3-A2 and NJT-R3-A3-that effectively detect GI.1 and GI.7 virus-like particles (VLPs) through selection of a phage display library against the P-domain of the GI.1 major capsid protein. The limits of detection by each scFv for GI.1 and GI.7 are 0.1 and 0.2 ng, and 6.25 and 25 ng, respectively. They detect VLPs with strong specificity in multiple diagnostic formats, including ELISAs and membrane-based dot blots, and in the context of norovirus-negative stool suspensions. The scFvs also detect native virions effectively in norovirus-positive clinical stool samples. Purified scFvs bind to GI.1 and GI.7 VLPs with equilibrium constant (KD) values of 27 nM and 49 nM, respectively. Overall, the phage-based scFv reagents identified and characterized here show utility for detecting GI.1 and GI.7 noroviruses in multiple diagnostic assay formats with strong specificity and sensitivity, indicating promise for integration into existing point-of-care tests to improve future diagnostics.

  17. Genotypic and Epidemiologic Trends of Norovirus Outbreaks in the United States, 2009 to 2013

    PubMed Central

    Barclay, Leslie; Gregoricus, Nicole; Shirley, S. Hannah; Lee, David

    2014-01-01

    Noroviruses are the leading cause of epidemic acute gastroenteritis in the United States. From September 2009 through August 2013, 3,960 norovirus outbreaks were reported to CaliciNet. Of the 2,895 outbreaks with a known transmission route, person-to-person and food-borne transmissions were reported for 2,425 (83.7%) and 465 (16.1%) of the outbreaks, respectively. A total of 2,475 outbreaks (62.5%) occurred in long-term care facilities (LTCF), 389 (9.8%) in restaurants, and 227 (5.7%) in schools. A total of 435 outbreaks (11%) were typed as genogroup I (GI) and 3,525 (89%) as GII noroviruses. GII.4 viruses caused 2,853 (72%) of all outbreaks, of which 94% typed as either GII.4 New Orleans or GII.4 Sydney. In addition, three non-GII.4 viruses, i.e., GII.12, GII.1, and GI.6, caused 528 (13%) of all outbreaks. Several non-GII.4 genotypes (GI.3, GI.6, GI.7, GII.3, GII.6, and GII.12) were significantly more associated with food-borne transmission (odds ratio, 1.9 to 7.1; P < 0.05). Patients in LTCF and people ≥65 years of age were at higher risk for GII.4 infections than those in other settings and with other genotypes (P < 0.05). Phylogeographic analysis identified three major dispersions from two geographic locations that were responsible for the GI.6 outbreaks from 2011 to 2013. In conclusion, our data demonstrate the cyclic emergence of new (non-GII.4) norovirus strains, and several genotypes are more often associated with food-borne outbreaks. These surveillance data can be used to improve viral food-borne surveillance and to help guide studies to develop and evaluate targeted prevention methods such as norovirus vaccines, antivirals, and environmental decontamination methods. PMID:24172151

  18. Genotypic and epidemiologic trends of norovirus outbreaks in the United States, 2009 to 2013.

    PubMed

    Vega, Everardo; Barclay, Leslie; Gregoricus, Nicole; Shirley, S Hannah; Lee, David; Vinjé, Jan

    2014-01-01

    Noroviruses are the leading cause of epidemic acute gastroenteritis in the United States. From September 2009 through August 2013, 3,960 norovirus outbreaks were reported to CaliciNet. Of the 2,895 outbreaks with a known transmission route, person-to-person and food-borne transmissions were reported for 2,425 (83.7%) and 465 (16.1%) of the outbreaks, respectively. A total of 2,475 outbreaks (62.5%) occurred in long-term care facilities (LTCF), 389 (9.8%) in restaurants, and 227 (5.7%) in schools. A total of 435 outbreaks (11%) were typed as genogroup I (GI) and 3,525 (89%) as GII noroviruses. GII.4 viruses caused 2,853 (72%) of all outbreaks, of which 94% typed as either GII.4 New Orleans or GII.4 Sydney. In addition, three non-GII.4 viruses, i.e., GII.12, GII.1, and GI.6, caused 528 (13%) of all outbreaks. Several non-GII.4 genotypes (GI.3, GI.6, GI.7, GII.3, GII.6, and GII.12) were significantly more associated with food-borne transmission (odds ratio, 1.9 to 7.1; P < 0.05). Patients in LTCF and people ≥65 years of age were at higher risk for GII.4 infections than those in other settings and with other genotypes (P < 0.05). Phylogeographic analysis identified three major dispersions from two geographic locations that were responsible for the GI.6 outbreaks from 2011 to 2013. In conclusion, our data demonstrate the cyclic emergence of new (non-GII.4) norovirus strains, and several genotypes are more often associated with food-borne outbreaks. These surveillance data can be used to improve viral food-borne surveillance and to help guide studies to develop and evaluate targeted prevention methods such as norovirus vaccines, antivirals, and environmental decontamination methods.

  19. A non-foodborne norovirus outbreak among school children during a skiing holiday, Austria, 2007.

    PubMed

    Kuo, Hung-Wei; Schmid, Daniela; Schwarz, Karin; Pichler, Anna-Margaretha; Klein, Heidelinde; König, Christoph; de Martin, Alfred; Allerberger, Franz

    2009-01-01

    Norovirus is increasingly recognized as a leading cause of outbreaks of foodborne disease. We report on an outbreak in Austria that reached a total of 176 cases, affecting pupils and teachers from four schools on a skiing holiday in a youth hostel in the province of Salzburg in December 2007. A questionnaire was sent to the four schools in order to obtain data from persons attending the school trip on disease status, clinical onset, duration of illness and hospitalization. A cohort study was undertaken to identify the sources of infection. The school trip attendees were interviewed by questionnaire or face-to-face on their exposure to food items from the menu provided by the hostel owner. Of the 284 school holiday-makers, 176 fitted the definition of an outbreak case (attack rate 61.9%). A total of 264 persons on the ski holiday participated in the cohort study (response rate 93%). The day-by-day food-specific analyses did not find any food items served on any of five days (December 8-12) of the holiday to be associated with infection risk. The day-specific risk analyses revealed Monday December 10 (RR: 9.04; 95% CI: 6.02-13.6; P < 0.001) and Tuesday December 11 (RR: 3.37; 95% CI: 2.56-4.43; P < 0.001) as the two most risky days for having being exposed to norovirus. According to the epidemiological investigation, airborne transmission of norovirus originating from the first vomiting case most probably initiated this outbreak; foodborne genesis was excluded. During recent years, norovirus has become increasingly established as the most important causative agent of epidemic gastroenteritis in holiday-makers all over Europe. Tourism is one of the primary industries in Austria. Timely involvement of the relevant public health authorities is essential in any outbreak of norovirus gastroenteritis, irrespective of its genesis.

  20. Virucidal Effectiveness Testing Using Feline Calicivirus as Surrogate for Norovirus

    EPA Pesticide Factsheets

    These documents describe the effectiveness test using Feline Calicivirus as Surrogate for Norovirus, including initial and confirmatory testing and testing with pre-saturated or impregnated towelettes.

  1. Crystal Structures of GII.10 and GII.12 Norovirus Protruding Domains in Complex with Histo-Blood Group Antigens Reveal Details for a Potential Site of Vulnerability

    SciTech Connect

    Hansman, Grant S.; Biertümpfel, Christian; Georgiev, Ivelin; McLellan, Jason S.; Chen, Lei; Zhou, Tongqing; Katayama, Kazuhiko; Kwong, Peter D.

    2011-10-10

    Noroviruses are the dominant cause of outbreaks of gastroenteritis worldwide, and interactions with human histo-blood group antigens (HBGAs) are thought to play a critical role in their entry mechanism. Structures of noroviruses from genogroups GI and GII in complex with HBGAs, however, reveal different modes of interaction. To gain insight into norovirus recognition of HBGAs, we determined crystal structures of norovirus protruding domains from two rarely detected GII genotypes, GII.10 and GII.12, alone and in complex with a panel of HBGAs, and analyzed structure-function implications related to conservation of the HBGA binding pocket. The GII.10- and GII.12-apo structures as well as the previously solved GII.4-apo structure resembled each other more closely than the GI.1-derived structure, and all three GII structures showed similar modes of HBGA recognition. The primary GII norovirus-HBGA interaction involved six hydrogen bonds between a terminal {alpha}fucose1-2 of the HBGAs and a dimeric capsid interface, which was composed of elements from two protruding subdomains. Norovirus interactions with other saccharide units of the HBGAs were variable and involved fewer hydrogen bonds. Sequence analysis revealed a site of GII norovirus sequence conservation to reside under the critical {alpha}fucose1-2 and to be one of the few patches of conserved residues on the outer virion-capsid surface. The site was smaller than that involved in full HBGA recognition, a consequence of variable recognition of peripheral saccharides. Despite this evasion tactic, the HBGA site of viral vulnerability may provide a viable target for small molecule- and antibody-mediated neutralization of GII norovirus.

  2. Early Detection of Epidemic GII-4 Norovirus Strains in UK and Malawi: Role of Surveillance of Sporadic Acute Gastroenteritis in Anticipating Global Epidemics

    PubMed Central

    Callaghan, Anna; O’Brien, Sarah J.; Cunliffe, Nigel A.; Iturriza-Gómara, Miren

    2016-01-01

    Noroviruses are endemic in the human population, and are recognised as a leading cause of acute gastroenteritis worldwide. Although they are a highly diverse group of viruses, genogroup-II genotype-4 (GII-4) noroviruses are the most frequently identified strains worldwide. The predominance of GII-4 norovirus strains is driven by the periodic emergence of antigenic variants capable of evading herd protection. The global molecular epidemiology of emerging GII-4 strains is largely based on data from outbreak surveillance programmes, but the epidemiology of GII-4 strains among sporadic or community cases is far less well studied. To understand the distribution of GII-4 norovirus strains associated with gastroenteritis in the wider population, we characterised the GII-4 norovirus strains detected during studies of sporadic cases of infectious gastroenteritis collected in the UK and Malawi between 1993 and 2009. Our data shows that GII-4 norovirus strains that have emerged as strains of global epidemic importance have circulated in the community up to 18 years before their recognition as pandemic strains associated with increases in outbreaks. These data may suggest that more comprehensive surveillance programmes that incorporate strains associated with sporadic cases may provide a way for early detection of emerging strains with pandemic potential. This may be of particular relevance as vaccines become available. PMID:27115152

  3. Functional receptor molecules CD300lf and CD300ld within the CD300 family enable murine noroviruses to infect cells

    PubMed Central

    Haga, Kei; Fujimoto, Akira; Takai-Todaka, Reiko; Miki, Motohiro; Doan, Yen Hai; Murakami, Kosuke; Yokoyama, Masaru; Murata, Kazuyoshi; Nakanishi, Akira; Katayama, Kazuhiko

    2016-01-01

    Norovirus is the leading cause of acute gastroenteritis worldwide. Since the discovery of human norovirus (HuNoV), an efficient and reproducible norovirus replication system has not been established in cultured cells. Although limited amounts of virus particles can be produced when the HuNoV genome is directly transfected into cells, the HuNoV cycle of infection has not been successfully reproduced in any currently available cell-culture system. Those results imply that the identification of a functional cell-surface receptor for norovirus might be the key to establishing a norovirus culture system. Using a genome-wide CRISPR/Cas9 guide RNA library, we identified murine CD300lf and CD300ld as functional receptors for murine norovirus (MNV). The treatment of susceptible cells with polyclonal antibody against CD300lf significantly reduced the production of viral progeny. Additionally, ectopic CD300lf expression in nonsusceptible cell lines derived from other animal species enabled MNV infection and progeny production, suggesting that CD300lf has potential for dictating MNV host tropism. Furthermore, CD300ld, which has an amino acid sequence in the N-terminal region of its extracellular domain that is highly homologous to that of CD300lf, also functions as a receptor for MNV. Our results indicate that direct interaction of MNV with two cell-surface molecules, CD300lf and CD300ld, dictates permissive noroviral infection. PMID:27681626

  4. Inactivation of murine norovirus by chemical biocides on stainless steel

    PubMed Central

    2009-01-01

    Background Human norovirus (NoV) causes more than 80% of nonbacterial gastroenteritis in Europe and the United States. NoV transmission via contaminated surfaces may be significant for the spread of viruses. Therefore, measures for prevention and control, such as surface disinfection, are necessary to interrupt the dissemination of human NoV. Murine norovirus (MNV) as a surrogate for human NoV was used to study the efficacy of active ingredients of chemical disinfectants for virus inactivation on inanimate surfaces. Methods The inactivating properties of different chemical biocides were tested in a quantitative carrier test with stainless steel discs without mechanical action. Vacuum-dried MNV was exposed to different concentrations of alcohols, peracetic acid (PAA) or glutaraldehyde (GDA) for 5 minutes exposure time. Detection of residual virus was determined by endpoint-titration on RAW 264.7 cells. Results PAA [1000 ppm], GDA [2500 ppm], ethanol [50% (v/v)] and 1-propanol [30% (v/v)] were able to inactivate MNV under clean conditions (0.03% BSA) on the carriers by ≥ 4 log10 within 5 minutes exposure time, whereas 2-propanol showed a reduced effectiveness even at 60% (v/v). Furthermore, there were no significant differences in virus reduction whatever interfering substances were used. When testing with ethanol, 1- and 2-propanol, results under clean conditions were nearly the same as in the presence of dirty conditions (0.3% BSA plus 0.3% erythrocytes). Conclusion Products based upon PAA, GDA, ethanol and 1-propanol should be used for NoV inactivation on inanimate surfaces. Our data provide valuable information for the development of strategies to control NoV transmission via surfaces. PMID:19583832

  5. A critical review on the survival and elimination of norovirus in food and on food contact surfaces

    USDA-ARS?s Scientific Manuscript database

    This critical review covers the survival of human norovirus (NoV) in foods and on food contact surfaces as well as the state-of-the-art on the effectiveness of methods to eliminate these viruses. Virus survival studies are reviewed for water, soils and organic wastes, on fomites, hands, fruits and v...

  6. Development of one-step Loop-Mediated Isothermal Amplification (LAMP) for the detection of norovirus in oysters

    USDA-ARS?s Scientific Manuscript database

    The aim of this study was to develop a simple and rapid technique for detecting human norovirus (NoV). The loop-mediated isothermal amplification (LAMP) technique was evaluated and found to be sensitive, highly specific, and useful for routine oyster testing. Reverse transcription-LAMP (RT-LAMP) pri...

  7. A Single-Amino-Acid Substitution in the P2 Domain of VP1 of Murine Norovirus Is Sufficient for Escape from Antibody Neutralization▿

    PubMed Central

    Lochridge, Vance P.; Hardy, Michele E.

    2007-01-01

    Noroviruses cause epidemic outbreaks of acute viral gastroenteritis worldwide, and the number of reported outbreaks is increasing. Human norovirus strains do not grow in cell culture. However, murine norovirus (MNV) replicates in the RAW 264.7 macrophage cell line and thus provides a tractable model to investigate norovirus interactions with host cells. Epitopes recognized by monoclonal antibodies (MAbs) against the human norovirus strains Norwalk virus and Snow Mountain virus (SMV) identified regions in the P domain of major capsid protein VP1 important for interactions with putative cellular receptors. To determine if there was a relationship between domains of MNV VP1 and VP1 of human norovirus strains involved in cell binding, epitope mapping by phage display was performed with an MNV-1-neutralizing MAb, A6.2.1. A consensus peptide, GWWEDHGQL, was derived from 20 third-round phage clones. A synthetic peptide containing this sequence and constrained through a disulfide linkage reacted strongly with the A6.2.1 MAb, whereas the linear sequence did not. Four residues in the A6.2.1-selected peptide, G327, G333, Q334, and L335, aligned with amino acid residues in the P2 domain of MNV-1 VP1. This sequence is immediately adjacent to the epitope recognized by anti-SMV MAb 61.21. Neutralization escape mutants selected with MAb A6.2.1 contained a leucine-to-phenylalanine substitution at position 386 in the P2 domain. The predicted location of these residues on VP1 suggests that the phage peptide and the mutation in the neutralization-resistant viruses may be in close proximity to each other and to residues reported to be important for carbohydrate binding to VP1 of human norovirus strains. PMID:17804495

  8. Genotype considerations for virus-like particle-based bivalent norovirus vaccine composition.

    PubMed

    Malm, Maria; Tamminen, Kirsi; Lappalainen, Suvi; Uusi-Kerttula, Hanni; Vesikari, Timo; Blazevic, Vesna

    2015-06-01

    Norovirus (NoV) genogroup I (GI) and GII are responsible for most human infections with NoV. Because of the high genetic variability of NoV, natural infection does not induce sufficient protective immunity to different genotypes or to variants of the same genotype and there is little or no cross-protection against different genogroups. NoV-derived virus-like particles (VLPs) are promising vaccine candidates that induce high levels of NoV-specific humoral and cellular immune responses. It is believed that a bivalent NoV vaccine consisting of a representative VLP from GI and GII is a minimum requirement for an effective vaccine. Here, we compared the abilities of monovalent immunizations with NoV GI.1-2001, GI.3-2002, GII.4-1999, and GII.4-2010 New Orleans VLPs to induce NoV type-specific and cross-reactive immune responses and protective blocking antibody responses in BALB/c mice. All of the VLPs induced comparable levels of type-specific serum IgG antibodies, as well as blocking antibodies to the VLPs used for immunization. However, the abilities of different VLP genotypes to induce cross-reactive IgG and cross-blocking antibodies varied remarkably. Our results confirm previous findings of a lack of cross-protective immune responses between GI and GII NoVs. These data support the rationale for including NoV GI.3 and GII.4-1999 VLPs in the bivalent vaccine formulation, which could be sufficient to induce protective immune responses across NoV genotypes in the two common genogroups in humans. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Asymptomatic Norovirus Infection in Mexican Children

    PubMed Central

    García, Coralith; DuPont, Herbert L.; Long, Kurt Z.; Santos, Jose I.; Ko, GwangPyo

    2006-01-01

    Sixty-three children in periurban Mexico City were examined for the occurrence of asymptomatic norovirus (NoV) infection from June to August 1998. NoV was detected in 48 of 161 stool specimens (29.8%), with 31 children (49.2%) having at least one positive stool. Asymptomatic NoV infection occurred commonly during summertime in a Mexican pediatric population. PMID:16891526

  10. Emergence of GII.4 Sydney norovirus in South Korea during the winter of 2012-2013.

    PubMed

    Kim, Hyun Soo; Hyun, Jeongwon; Kim, Han-Sung; Kim, Jae-Seok; Song, Wonkeun; Lee, Kyu Man

    2013-11-28

    Norovirus is the major cause of acute gastroenteritis worldwide. Between November 2012 and June 2013, 1718 stool samples were requested for norovirus antigen testing in the metropolitan areas of South Korea, and 91 samples were genotyped. The norovirus antigen-positive rate peaked at 52.8% in December 2012. [corrected]. A novel norovirus GII.4 variant, GII.4 Sydney 2012, was the most frequently found genotype (60.4%) during this period. This study demonstrates that norovirus activity increased during the winter of 2012-2013 in South Korea and that norovirus GII.4 Sydney 2012 was the cause of the norovirus epidemic during this period.

  11. Human Response to Emergency Warning

    NASA Astrophysics Data System (ADS)

    Sorensen, J.

    2009-12-01

    Almost every day people evacuate from their homes, businesses or other sites, even ships, in response to actual or predicted threats or hazards. Evacuation is the primary protective action utilized in large-scale emergencies such as hurricanes, floods, tornados, tsunamis, volcanic eruptions, or wildfires. Although often precautionary, protecting human lives by temporally relocating populations before or during times of threat remains a major emergency management strategy. One of the most formidable challenges facing emergency officials is evacuating residents for a fast-moving and largely unpredictable event such as a wildfire or a local tsunami. How to issue effective warnings to those at risk in time for residents to take appropriate action is an on-going problem. To do so, some communities have instituted advanced communications systems that include reverse telephone call-down systems or other alerting systems to notify at-risk residents of imminent threats. This presentation examines the effectiveness of using reverse telephone call-down systems for warning San Diego residents of wildfires in the October of 2007. This is the first systematic study conducted on this topic and is based on interviews with 1200 households in the evacuation areas.

  12. Comparative survival of Escherichia coli O157:H7, Salmonella Typhimurium, and Murine Norovirus on spinach plants

    USDA-ARS?s Scientific Manuscript database

    Introduction: Outbreaks resulting from the consumption of leafy greens contaminated with E. coli O157:H7, Salmonella spp., and norovirus have occurred. It is unclear how the stress response factor rpoS in E. coli O157:H7 and Salmonella spp. affects their survival on spinach. Purpose: A comparison ...

  13. Identifying Potential Norovirus Epidemics in China via Internet Surveillance.

    PubMed

    Liu, Kui; Huang, Sichao; Miao, Zi-Ping; Chen, Bin; Jiang, Tao; Cai, Gaofeng; Jiang, Zhenggang; Chen, Yongdi; Wang, Zhengting; Gu, Hua; Chai, Chengliang; Jiang, Jianmin

    2017-08-08

    Norovirus is a common virus that causes acute gastroenteritis worldwide, but a monitoring system for norovirus is unavailable in China. We aimed to identify norovirus epidemics through Internet surveillance and construct an appropriate model to predict potential norovirus infections. The norovirus-related data of a selected outbreak in Jiaxing Municipality, Zhejiang Province of China, in 2014 were collected from immediate epidemiological investigation, and the Internet search volume, as indicated by the Baidu Index, was acquired from the Baidu search engine. All correlated search keywords in relation to norovirus were captured, screened, and composited to establish the composite Baidu Index at different time lags by Spearman rank correlation. The optimal model was chosen and possibly predicted maps in Zhejiang Province were presented by ArcGIS software. The combination of two vital keywords at a time lag of 1 day was ultimately identified as optimal (ρ=.924, P<.001). The exponential curve model was constructed to fit the trend of this epidemic, suggesting that a one-unit increase in the mean composite Baidu Index contributed to an increase of norovirus infections by 2.15 times during the outbreak. In addition to Jiaxing Municipality, Hangzhou Municipality might have had some potential epidemics in the study time from the predicted model. Although there are limitations with early warning and unavoidable biases, Internet surveillance may be still useful for the monitoring of norovirus epidemics when a monitoring system is unavailable.

  14. Lessons Learned from an Elementary School Norovirus Outbreak

    ERIC Educational Resources Information Center

    Gomez, Eileen Button

    2008-01-01

    Outbreaks of norovirus have been on the increase. The virus often spreads quickly through schools and similar institutions. The school nurse may be able to minimize the impact of a school norovirus outbreak by providing accurate information about the disease, the scope of the local situation, and instruction on infection control measures. This…

  15. EVALUATION OF A GENERIC ARRAY APPROACH FOR GENOTYPING NOROVIRUSES

    EPA Science Inventory

    Noroviruses are the leading cause of nonbacterial gastroenteritis outbreaks in the United States. Because of their potential to contaminate drinking water, the U.S Environmental Protection Agency has included noroviruses on the Contaminant Candidate List (CCL) to assess the publi...

  16. Lessons Learned from an Elementary School Norovirus Outbreak

    ERIC Educational Resources Information Center

    Gomez, Eileen Button

    2008-01-01

    Outbreaks of norovirus have been on the increase. The virus often spreads quickly through schools and similar institutions. The school nurse may be able to minimize the impact of a school norovirus outbreak by providing accurate information about the disease, the scope of the local situation, and instruction on infection control measures. This…

  17. Identifying Potential Norovirus Epidemics in China via Internet Surveillance

    PubMed Central

    Chen, Bin; Jiang, Tao; Cai, Gaofeng; Jiang, Zhenggang; Chen, Yongdi; Wang, Zhengting; Gu, Hua; Chai, Chengliang

    2017-01-01

    Background Norovirus is a common virus that causes acute gastroenteritis worldwide, but a monitoring system for norovirus is unavailable in China. Objective We aimed to identify norovirus epidemics through Internet surveillance and construct an appropriate model to predict potential norovirus infections. Methods The norovirus-related data of a selected outbreak in Jiaxing Municipality, Zhejiang Province of China, in 2014 were collected from immediate epidemiological investigation, and the Internet search volume, as indicated by the Baidu Index, was acquired from the Baidu search engine. All correlated search keywords in relation to norovirus were captured, screened, and composited to establish the composite Baidu Index at different time lags by Spearman rank correlation. The optimal model was chosen and possibly predicted maps in Zhejiang Province were presented by ArcGIS software. Results The combination of two vital keywords at a time lag of 1 day was ultimately identified as optimal (ρ=.924, P<.001). The exponential curve model was constructed to fit the trend of this epidemic, suggesting that a one-unit increase in the mean composite Baidu Index contributed to an increase of norovirus infections by 2.15 times during the outbreak. In addition to Jiaxing Municipality, Hangzhou Municipality might have had some potential epidemics in the study time from the predicted model. Conclusions Although there are limitations with early warning and unavoidable biases, Internet surveillance may be still useful for the monitoring of norovirus epidemics when a monitoring system is unavailable. PMID:28790023

  18. EVALUATION OF A GENERIC ARRAY APPROACH FOR GENOTYPING NOROVIRUSES

    EPA Science Inventory

    Noroviruses are the leading cause of nonbacterial gastroenteritis outbreaks in the United States. Because of their potential to contaminate drinking water, the U.S Environmental Protection Agency has included noroviruses on the Contaminant Candidate List (CCL) to assess the publi...

  19. Murine norovirus 1 (MNV1) replication induces translational control of the host by regulating eIF4E activity during infection.

    PubMed

    Royall, Elizabeth; Doyle, Nicole; Abdul-Wahab, Azimah; Emmott, Ed; Morley, Simon J; Goodfellow, Ian; Roberts, Lisa O; Locker, Nicolas

    2015-02-20

    Protein synthesis is a tightly controlled process responding to several stimuli, including viral infection. As obligate intracellular parasites, viruses depend on the translation machinery of the host and can manipulate it by affecting the availability and function of specific eukaryotic initiation factors (eIFs). Human norovirus is a member of the Caliciviridae family and is responsible for gastroenteritis outbreaks. Previous studies on feline calicivirus and murine norovirus 1 (MNV1) demonstrated that the viral protein, genome-linked (VPg), acts to direct translation by hijacking the host protein synthesis machinery. Here we report that MNV1 infection modulates the MAPK pathway to activate eIF4E phosphorylation. Our results show that the activation of p38 and Mnk during MNV1 infection is important for MNV1 replication. Furthermore, phosphorylated eIF4E relocates to the polysomes, and this contributes to changes in the translational state of specific host mRNAs. We propose that global translational control of the host by eIF4E phosphorylation is a key component of the host-pathogen interaction. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Murine Norovirus 1 (MNV1) Replication Induces Translational Control of the Host by Regulating eIF4E Activity during Infection*

    PubMed Central

    Royall, Elizabeth; Doyle, Nicole; Abdul-Wahab, Azimah; Emmott, Ed; Morley, Simon J.; Goodfellow, Ian; Roberts, Lisa O.; Locker, Nicolas

    2015-01-01

    Protein synthesis is a tightly controlled process responding to several stimuli, including viral infection. As obligate intracellular parasites, viruses depend on the translation machinery of the host and can manipulate it by affecting the availability and function of specific eukaryotic initiation factors (eIFs). Human norovirus is a member of the Caliciviridae family and is responsible for gastroenteritis outbreaks. Previous studies on feline calicivirus and murine norovirus 1 (MNV1) demonstrated that the viral protein, genome-linked (VPg), acts to direct translation by hijacking the host protein synthesis machinery. Here we report that MNV1 infection modulates the MAPK pathway to activate eIF4E phosphorylation. Our results show that the activation of p38 and Mnk during MNV1 infection is important for MNV1 replication. Furthermore, phosphorylated eIF4E relocates to the polysomes, and this contributes to changes in the translational state of specific host mRNAs. We propose that global translational control of the host by eIF4E phosphorylation is a key component of the host-pathogen interaction. PMID:25561727

  1. Evaluating Rotavirus and Norovirus transport processes in standardised and natural soil-water columns experiments

    NASA Astrophysics Data System (ADS)

    Gamazo, Pablo; Schijven, Jack; Victoria, Matias; Alvareda, Elena; López Tort, Fernando; Ramos, Julián; Lizasoain, Andrés; Sapriza, Gonzalo; Castells, Matias; Colina, Rodney

    2017-04-01

    In Uruguay, as in many developed and developing countries, rotavirus and norovirus are major causes of diarrhea and others symptoms of acute gastroenteritis. In some areas of Uruguay, groundwater is the only source of water for human consumption. In the rural area of the Salto district, virus contamination has been detected in several groundwater wells. Because sewer coverage is low, the most probable sources of contamination are nearby septic systems. This work aims to evaluate the transport of rotavirus and norovirus from clinic samples in two sets of column experiments under saturated conditions: 6.7-cm columns with quartz sand (ionic strength 1mM, pH 7.0) and with sand from the Salto aquifer (Uruguay) (9,2% coarse sand, 47,8% medium sand, 40,5% fine sand, magnesium/calcium bicarbonate water, Ionic strength 15.1 mM, pH 7.2). Both viruses were seeded for 2 pore volumes onto the columns. Samples were collected at the column outlet and viruses were enumerated by Q-PRCR. Breakthrough curves were constructed and fitted to a two-site kinetic attachment/detachment model, including blocking using Hydrus-1D. In the quartz sand column, both rotavirus and norovirus were removed two orders in magnitude. In the Salto sand column, rotavirus was removed 2 log10 as well, but norovirus was removed 4 log10. The fitting of the breakthrough curves indicated that blocking played a role for rotavirus in the Salto sand column. These results are consistent with the field observation where only rotavirus was detected in the Salto aquifer, while similar concentrations in Salto sewer effluent were measured for both viruses. This work, besides reporting actual parameters values for human virus transport modelling, shows the significant differences in transport that human viruses can have in standardised and natural soil-water systems.

  2. Surface plasmon resonance biosensor for detection of feline calicivirus, a surrogate for norovirus.

    PubMed

    Yakes, Betsy Jean; Papafragkou, Efstathia; Conrad, Stephen M; Neill, John D; Ridpath, Julia F; Burkhardt, William; Kulka, Michael; Degrasse, Stacey L

    2013-03-15

    The human noroviruses are the most common non-bacterial cause of gastroenteritis and are responsible for as much as 50% of all gastroenteritis outbreaks worldwide. Norovirus (NoV), a single stranded RNA virus, is highly contagious with an infectious dose of less than 100 viral particles. While techniques exist for the identification of NoV, the lack of a reliable cell culture system, NoV genetic variability, and time-consuming sample preparation steps required to isolate the virus (or its genome) prior to molecular based methods has hindered rapid virus detection. To better protect the public from virus-contaminated food and enable better detection in clinical and environmental samples, sensitive and selective methods with simple sample preparation are needed. Surface plasmon resonance (SPR) biosensors represent an emerging detection platform, and this approach has been applied to the rapid detection of foodborne small molecule t