| a comparative study of digital rt-pcr and rt-qpcr for quantification of hepatitis a virus and norovirus in lettuce and water samples. | sensitive and quantitative detection of foodborne enteric viruses is classically achieved by quantitative rt-pcr (rt-qpcr). recently, digital pcr (dpcr) was described as a novel approach to genome quantification without need for a standard curve. the performance of microfluidic digital rt-pcr (rt-dpcr) was compared to rt-qpcr for detecting the main viruses responsible for foodborne outbreaks (human noroviruses (nov) and hepatitis a virus (hav)) in spiked lettuce and bottled water. two process co ... | 2015 | 25725459 |
| survival of murine norovirus, tulane virus, and hepatitis a virus on alfalfa seeds and sprouts during storage and germination. | human norovirus (hunov) and hepatitis a virus (hav) have been involved in several produce-associated outbreaks and identified as major food-borne viral etiologies. in this study, the survival of hunov surrogates (murine norovirus [mnv] and tulane virus [tv]) and hav was investigated on alfalfa seeds during storage and postgermination. alfalfa seeds were inoculated with mnv, tv, or hav with titers of 6.46 ± 0.06 log pfu/g, 3.87 ± 0.38 log pfu/g, or 7.01 ± 0.07 log 50% tissue culture infectious do ... | 2013 | 24014537 |
| inactivation of internalized and surface contaminated enteric viruses in green onions. | with increasing outbreaks of gastroenteritis associated with produce, it is important to assess interventions to reduce the risk of illness. uv, ozone and high pressure are non-thermal processing technologies that have potential to inactivate human pathogens on produce and allow the retention of fresh-like organoleptic properties. the objective of this study was to determine if uv, ozone, and high pressure are effective technologies compared to traditional chlorine spray on green onions to reduc ... | 2013 | 23973828 |
| comparison of two extraction methods for the detection of hepatitis a virus in lettuces using the murine norovirus as a process control. | enteric viruses are important agents of foodborne diseases. in recent years, raw fruits and vegetables have frequently been involved in foodborne transmission of enteric viruses to humans, particularly noroviruses and hepatitis a virus (hav). although viral contamination can occur at any stage of food processing, primary production is a critical stage in which prevention measures are essential to minimise the risk of infection to consumers. due to the low infectious doses and low concentrations ... | 2013 | 23702026 |
| susceptibility of murine norovirus and hepatitis a virus to electron beam irradiation in oysters and quantifying the reduction in potential infection risks. | consumption of raw oysters is an exposure route for human norovirus (nov) and hepatitis a virus (hav). therefore, efficient postharvest oyster treatment technology is needed to reduce public health risks. this study evaluated the inactivation of hav and the nov research surrogate, murine norovirus-1 (mnv-1), in oysters (crassostrea virginica) by electron beam (e-beam) irradiation. the reduction of potential infection risks was quantified for e-beam irradiation technology employed on raw oysters ... | 2013 | 23584781 |
| physical removal and transfer of murine norovirus and hepatitis a virus from contaminated produce by scrubbing and peeling. | 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 virus ... | 2013 | 23317861 |
| evaluation of viral concentration methods from irrigation and processing water. | four viral concentration methods were evaluated for their efficiency in recovering murine norovirus-1 (mnv-1) (surrogate for human noroviruses (nov)) and ms2 bacteriophages from processing water (1l) and four different types of irrigation water (bore hole water, rain water, open well and river water) (2-5l). three methods were based on the viral adsorption and elution principle, two methods using an electronegative ha-membrane (katayama et al., 2002), one method using an electropositive zetapor ... | 2013 | 23201288 |
| temperature and humidity influences on inactivation kinetics of enteric viruses on surfaces. | norovirus (nov) and hepatitis a virus (hav) are pathogenic enteric viruses responsible for public health concerns worldwide. the viral transmission occurs through fecally contaminated food, water, fomites, or direct contact. however, the difficulty in cultivating these viruses makes it a challenge to characterize the resistance to various environmental stresses. in this study, we characterized the inactivation rates of murine norovirus (mnv), ms2, and hav on either lacquer coating rubber tree wo ... | 2012 | 23152976 |
| stability of human enteric viruses in seawater samples from mollusc depuration tanks coupled with ultraviolet irradiation. | to evaluate the stability in seawater of human adenovirus (hadv2), murine norovirus (mnv-1) and hepatitis a virus (hav) in a shellfish depuration system with and without ultraviolet (uv) treatment. | 2012 | 22967243 |
| comparison of two extraction methods for the detection of hepatitis a virus in semi-dried tomatoes and murine norovirus as a process control by duplex rt-qpcr. | enteric viruses are important agents of foodborne diseases. due to their low infectious doses and low concentrations in food samples, an efficient and rapid virus concentration method is required for routine control. because of the absence of a reliable cell culture method for most of the enteric viruses involved in outbreaks, reverse transcription quantitative real-time pcr (rt-qpcr) is now widely used for the detection of rna viruses in food samples. one of the general requirements for viral d ... | 2012 | 22608230 |
| transfer of pathogens from cantaloupe rind to preparation surfaces and edible tissue as a function of cutting method. | whole and cut cantaloupes have been implicated as vehicles in foodborne illness outbreaks of norovirus, salmonellosis, and listeriosis. preparation methods that minimize pathogen transfer from external surfaces to the edible tissue are needed. two preparation methods were compared for the transfer of listeria monocytogenes, salmonella enterica serovar typhimurium lt2, murine norovirus, and tulane virus from inoculated cantaloupe rinds to edible tissue and preparation surfaces. for the first meth ... | 2016 | 27296423 |
| anti-infective activity of 2-cyano-3-acrylamide inhibitors with improved drug-like properties against two intracellular pathogens. | due to the rise of antibiotic resistance and the small number of effective antiviral drugs, new approaches for treating infectious diseases are urgently needed. identifying targets for host-based therapies represents an emerging strategy for drug discovery. the ubiquitin-proteasome system is a central mode of signaling in the eukaryotic cell and may be a promising target for therapies that bolster the host's ability to control infection. deubiquitinase (dub) enzymes are key regulators of the hos ... | 2016 | 27139470 |
| virus recovering from strawberries: evaluation of a skimmed milk organic flocculation method for assessment of microbiological contamination. | skimmed milk organic flocculation method was adapted, optimized and compared with polyethylene glycol (peg) precipitation and filtration methods for recovering viruses from a strawberry matrix. spiking experiments with norovirus genogroup ii genotype 4 (nov gii.4) and murine norovirus 1 (mnv-1) demonstrated that the organic flocculation method associated with a glycine elution buffer, filter bag and cetyltrimethylammonium bromide (ctab) showed a recovery percentage of 2.5 and 32 times higher tha ... | 2016 | 26476572 |
| small molecule deubiquitinase inhibitors promote macrophage anti-infective capacity. | the global spread of anti-microbial resistance requires urgent attention, and diverse alternative strategies have been suggested to address this public health concern. host-directed immunomodulatory therapies represent one approach that could reduce selection for resistant bacterial strains. recently, the small molecule deubiquitinase inhibitor wp1130 was reported as a potential anti-infective drug against important human food-borne pathogens, notably listeria monocytogenes and noroviruses. util ... | 2014 | 25093325 |
| hygienic monitoring of mongolian gerbils: which mouse viruses should be included? | the mongolian gerbil (meriones unguiculatus) serves as an animal model for a wide range of diseases. a practical limitation in its use is the definition of the hygienic status, as not much is known about viruses that potentially infect gerbils and might be transmitted to other rodents. as successful re-derivation was recently described for gerbils, we now aimed at investigating which mouse viruses induce seroconversion in gerbils and might be transmitted to mice. gerbils were inoculated with vir ... | 2012 | 22334874 |
| protective role of murine norovirus against pseudomonas aeruginosa acute pneumonia. | 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 c ... | 2015 | 26338794 |
| novel murine norovirus-like genes in wild rodents in japan. | novel murine norovirus (mnv)-like sequences were detected in 7 (14.9%) of 47 fecal and intestinal samples obtained from wild rodents in japan. sequencing and genetic analyses of the 7 mnv-like genes, 6 derived from apodemus speciosus and 1 from rattus rattus, suggested that these sequences form a cluster distinct from known mnv within genogroup v and differed even among clusters of wild rodents. considering these results, mnv might be genetically diverse depending on the host species or distribu ... | 2012 | 22673564 |
| inactivation of viruses and bacteria on strawberries using a levulinic acid plus sodium dodecyl sulfate based sanitizer, taking sensorial and chemical food safety aspects into account. | the efficacy of levulinic acid (lva) in combination with sodium dodecyl sulfate (sds) in removal of foodborne viruses, enteric bacterial pathogens and their surrogates on fresh strawberries was investigated. inoculated strawberries were treated with potable water, sodium hypochlorite solution (50ppm), 0.5% lva plus 0.5% sds solution, and 5% lva plus 2% sds solution respectively for 2min, followed by spray-rinsing with potable water. water washing removed at least 1.0-log of the tested viral and ... | 2017 | 28668727 |
| effects of abiotic and biotic stresses on the internalization and dissemination of human norovirus surrogates in growing romaine lettuce. | 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 t ... | 2015 | 25956773 |
| norovirus: targets and tools in antiviral drug discovery. | 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 ho ... | 2014 | 24893351 |
| fluorinated tio₂ as an ambient light-activated virucidal surface coating material for the control of human norovirus. | 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 ... | 2014 | 25222145 |
| broad-spectrum non-nucleoside inhibitors for caliciviruses. | viruses of the caliciviridae cause significant and sometimes lethal diseases, however despite substantial research efforts, specific antivirals are lacking. broad-spectrum antivirals could combat multiple viral pathogens, offering a rapid solution when no therapies exist. the rna-dependent rna polymerase (rdrp) is an attractive antiviral target as it is essential for viral replication and lacks mammalian homologs. to focus the search for pan-caliciviridae antivirals, the rdrp was probed with non ... | 2017 | 28757394 |
| effect of green tea extract on enteric viruses and its application as natural sanitizer. | in this work, the effect of green tea extract (gte) was assessed against murine norovirus (mnv) and hepatitis a virus (hav) at different temperatures, exposure times and ph conditions. initially, gte at 0.5 and 5 mg/ml were individually mixed with each virus at 5 log tcid50/ml and incubated 2 h at 37 °c at different phs (from 5.5 to 8.5). gte affected both viruses depending on ph with higher reductions observed in alkaline conditions. secondly, different concentrations of gte (0.5 and 5 mg/ml) w ... | 2017 | 28576363 |
| detection of potential infectious enteric viruses in fresh produce by (rt)-qpcr preceded by nuclease treatment. | foodborne illnesses associated with contaminated fresh produce are a common public health problem and there is an upward trend of outbreaks caused by enteric viruses, especially human noroviruses (hnovs) and hepatitis a virus (hav). this study aimed to assess the use of dnase and rnase coupled to qpcr and rt-qpcr, respectively, to detect intact particles of human adenoviruses (hadvs), hnov gi and gii and hav in fresh produce. different concentrations of dnase and rnase were tested to optimize th ... | 2017 | 28452009 |
| inactivation of murine norovirus-1 and hepatitis a virus on fresh meats by atmospheric pressure plasma jets. | in the current study, inactivation effect of atmospheric pressure plasma (app) jets (10s-20min) was investigated against murine norovirus (mnv-1), as a norovirus (nov) surrogate and hepatitis a virus (hav) associated with three types of fresh meats (beef loin, pork shoulder and chicken breast). the quality characteristics of fresh meats, such as surface color, moisture content and thiobarbituric acid reactive substance (tbars) were also examined. after 5-20min of treatment with app jets, the red ... | 2015 | 28455013 |
| tracking human adenovirus inactivation by gamma radiation under different environmental conditions. | adenovirus is the most prevalent enteric virus in waters worldwide due to its environmental stability, which leads to public health concerns. mitigation strategies are therefore required. the aim of this study was to assess the inactivation of human adenovirus type 5 (hadv-5) by gamma radiation in aqueous environments. various substrates with different organic loads, including domestic wastewater, were inoculated with hadv-5 either individually or in a viral pool (with murine norovirus type 1 [m ... | 2016 | 27316961 |
| comparative inactivation of murine norovirus, human adenovirus, and human jc polyomavirus by chlorine in seawater. | 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 quantify ... | 2012 | 22773637 |
| antibacterial and antiviral effectiveness of two household water treatment devices that use monobrominated hydantoinylated polystyrene. | many different household water treatment (hwt) methods have been researched and promoted to mitigate the serious burden of diarrheal disease in developing countries. however, hwt methods using bromine have not been extensively evaluated. two gravity-fed hwt devices (aquasure™ and waterbird™) were used to test the antimicrobial effectiveness of halopure(®) br beads (monobrominated hydantoinylated polystyrene) that deliver bromine. as water flows over the beads, reactive bromine species are eluted ... | 2016 | 27959873 |
| effect of handling and storage conditions and stabilizing agent on the recovery of viral rna from oral fluid of pigs. | there is an increasing interest in using oral fluid to determine herd health and documenting the circulation of viruses in commercial swine populations but little is known about the stability of viruses in oral fluid. hepatitis e virus (hev) is a zoonotic virus which is widespread in swine herds. information on optimal handling methods such as heat treatments, freezing and rna stabilization agents is needed to prevent or minimize degradation of viral rna by degradative enzymes. the objectives of ... | 2014 | 24384096 |
| new perspectives regarding the antiviral effect of vitamin a on norovirus using modulation of gut microbiota. | gut microbiota has been revealed to play an important role in various health conditions, and recent studies have suggested the modulation of gut microbiota as a therapeutic strategy. there is no effective treatment of norovirus infection, though vitamin a has been suggested to have an antiviral effect in an epidemiological study. we demonstrated that vitamin a significantly inhibited murine norovirus replication. vitamin a supplementation significantly increased the abundance of lactobacillus sp ... | 2017 | 28727498 |
| pulsed light inactivation of murine norovirus, tulane virus, escherichia coli o157:h7 and salmonella in suspension and on berry surfaces. | pulsed light (pl) inactivation of two human norovirus (hunov) surrogates, murine norovirus (mnv-1) and tulane virus (tv), and two bacterial pathogens, escherichia coli o157:h7 and salmonella, were evaluated. the viruses and bacteria were suspended in phosphate buffered saline (pbs) to final populations of ∼6 log pfu/ml and ∼6 log cfu/ml, respectively. both viral and bacterial suspensions were then irradiated by pl for different durations and the reductions of each microorganisms were determined. ... | 2017 | 27697158 |
| norovirus transmission between hands, gloves, utensils, and fresh produce during simulated food handling. | human noroviruses (hunovs), a leading cause of food-borne gastroenteritis worldwide, are easily transferred via ready-to-eat (rte) foods, often prepared by infected food handlers. in this study, the transmission of hunov and murine norovirus (munov) from virus-contaminated hands to latex gloves during gloving, as well as from virus-contaminated donor surfaces to recipient surfaces after simulated preparation of cucumber sandwiches, was inspected. virus transfer was investigated by swabbing with ... | 2014 | 24951789 |
| the protective effects of lactoferrin against murine norovirus infection through inhibition of both viral attachment and replication. | the purpose of this study was to evaluate the effects of bovine lactoferrin against norovirus infection using mouse norovirus (mnv) and raw264.7 cell in vitro. when raw264.7 cells were infected with mnv in the presence or absence of lactoferrin, the cytotoxic damage to the infected raw264.7 cells significantly and dose-dependently decreased and completely inhibited in the presence of 15 or 20 μg/well of lactoferrin as compared with the absence of lactoferrin. correspondingly, the mnv titers in t ... | 2013 | 23603257 |
| evaluation of virus inactivation by formaldehyde to enhance biosafety of diagnostic electron microscopy. | formaldehyde (fa) fixation of infectious samples is a well-established protocol in diagnostic electron microscopy of viruses. however, published experimental data that demonstrate virus inactivation by these fixation procedures are lacking. usually, fixation is performed immediately before the sample preparation for microscopy. the fixation procedure should transform viruses in a non-infectious but nonetheless structurally intact form in order to allow a proper diagnosis based on morphology. fa ... | 2015 | 25674771 |
| infection of murine macrophages by salmonella enterica serovar heidelberg blocks murine norovirus infectivity and virus-induced apoptosis. | gastroenteritis caused by bacterial and viral pathogens constitutes a major public health threat in the united states accounting for 35% of hospitalizations. in particular, salmonella enterica and noroviruses cause the majority of gastroenteritis infections, with emergence of sporadic outbreaks and incidence of increased infections. although mechanisms underlying infections by these pathogens have been individually studied, little is known about the mechanisms regulating co-infection by these pa ... | 2015 | 26658916 |
| persistence and transferability of noroviruses on and between common surfaces and foods. | human noroviruses (hunov) are the leading cause of foodborne disease, and poor personal hygiene practices of infected workers are the most common mode of contamination. the purpose of this study was to characterize the persistence and transferability of representative noroviruses norwalk virus (nv), snow mountain virus (smv), and murine norovirus 1 (mnv-1) on and between solid surfaces and foods. changes in virus concentration on artificially inoculated solid surfaces (stainless steel, ceramic, ... | 2012 | 22564943 |
| antiviral activity of nucleoside analogues against norovirus. | norovirus (nov) is the leading cause of epidemic gastroenteritis worldwide. the lack of a cell culture has significantly hampered the development of effective therapies against human nov. clinically approved nucleoside and non-nucleoside analogues have been used successfully against rna viruses. | 2012 | 22910194 |
| structural and inhibitor studies of norovirus 3c-like proteases. | noroviruses have a single-stranded, positive sense 7-8kb rna genome, which encodes a polyprotein precursor processed by a virus-encoded 3c-like cysteine protease (3clpro) to generate mature non-structural proteins. because processing of the polyprotein is essential for virus replication, norovirus 3clpro has been targeted for the discovery of anti-norovirus small molecule therapeutics. thus, we performed functional, structural and inhibition studies of norovirus 3clpro with fluorescence resonanc ... | 2013 | 24055466 |
| replication of human norovirus rna in mammalian cells reveals lack of interferon response. | 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 pro ... | 2016 | 27466422 |
| the norovirus ns3 protein is a dynamic lipid- and microtubule-associated protein involved in viral rna replication. | norovirus (nov) infections are a significant health burden to society, yet the lack of reliable tissue culture systems has hampered the development of appropriate antiviral therapies. here we show that the nov ns3 protein, derived from murine nov (mnv), is intimately associated with the mnv replication complex and the viral replication intermediate double-stranded rna (dsrna). we observed that when expressed individually, mnv ns3 and ns3 encoded by human norwalk virus (nv) induced the formation ... | 2017 | 27881660 |
| effect of grape seed extract on human norovirus gii.4 and murine norovirus 1 in viral suspensions, on stainless steel discs, and in lettuce wash water. | the anti-norovirus (anti-nov) effect of grape seed extract (gse) was examined by plaque assay for murine norovirus 1 (mnv-1), cell-binding reverse transcription-pcr for human nov gii.4, and saliva-binding enzyme-linked immunosorbent assay for human nov gii.4 p particles, with or without the presence of interfering substances (dried milk and lettuce extract). gse at 0.2 and 2 mg/ml was shown to reduce the infectivity of mnv-1 (>3-log pfu/ml) and the specific binding ability of nov gii.4 to caco-2 ... | 2012 | 22904060 |
| persistence of human norovirus gii.4 and gi.4, murine norovirus, and human adenovirus on soft berries as compared with pbs at commonly applied storage conditions. | human noroviruses (hnov) have been detected on soft fruits. especially raspberries have been found to be associated with outbreaks of gastroenteritis suggesting persistence of hnov on these fruits. therefore, the persistence of hnov gii.4 and gi.4, murine norovirus (mnv-1, a culturable surrogate for hnov), and human adenovirus (hadv, an indicator for human fecal contamination), on raspberries, strawberries and in phosphate buffered saline (pbs) at 4°c, 10°c and 21°c, mimicking commonly applied s ... | 2012 | 23177054 |
| ultraviolet light inactivation of murine norovirus and human norovirus gii: pcr may overestimate the persistence of noroviruses even when combined with pre-pcr treatments. | transmission of gastroenteritis-causing noroviruses may be significant via contaminated surfaces. measures for control, e.g. disinfection with ultraviolet irradiation (uv), are therefore necessary for interrupting this transmission. human norovirus (hunov) gii.4 and murine norovirus (munov) were used to study the efficacy of uv for virus inactivation on dry glass surfaces. munov inactivation was measured using viability assay and the reduction in viral rna levels for both viruses using reverse t ... | 2014 | 24142397 |
| removal properties of human enteric viruses in a pilot-scale membrane bioreactor (mbr) process. | in order to evaluate removal properties of human enteric viruses from wastewater by a membrane bioreactor (mbr), influent, anoxic and oxic mixed liquor, and membrane effluent samples were collected in a pilot-scale anoxic-oxic mbr process for 16 months, and concentrations of enteroviruses, norovirus gii, and sapoviruses were determined by real-time pcr using murine norovirus as a process control. mixed liquor samples were separated into liquid and solid phases by centrifugation, and viruses in t ... | 2015 | 25770448 |
| detection and quantification of airborne norovirus during outbreaks in healthcare facilities. | noroviruses are responsible for at least 50% of all gastroenteritis outbreaks worldwide. noroviruses gii can infect humans via multiple routes including direct contact with an infected person, fecal matter, or vomitus, and contact with contaminated surfaces. although norovirus is an intestinal pathogen, aerosols could, if inhaled, settle in the pharynx and later be swallowed. the aims of this study were to investigate the presence of norovirus gii bioaerosols during gastroenteritis outbreaks in ... | 2015 | 25900175 |
| using reduced personal protective equipment in an endemically infected mouse colony. | personal protective equipment (ppe) frequently is used to reduce the risk of spreading adventitial diseases in rodent colonies. the ppe worn often reflects the historic practices of the research institution rather than published performance data. standard ppe for a rodent facility typically consists of a disposable hair bonnet, gown, face mask, shoe covers, and gloves, which are donned on facility entry and removed on exiting. this study evaluated the effect of a reduced ppe protocol on disease ... | 2014 | 24827569 |
| culture-independent evaluation of nonenveloped-virus infectivity reduced by free-chlorine disinfection. | the inability of molecular detection methods to distinguish disinfected virions from infectious ones has hampered the assessment of infectivity for enteric viruses caused by disinfection practices. in the present study, the reduction of infectivity of murine norovirus s7-pp3 and mengovirus vmc0, surrogates of human noroviruses and enteroviruses, respectively, caused by free-chlorine treatment was characterized culture independently by detecting carbonyl groups on viral capsid protein. the amount ... | 2015 | 25681178 |
| characterization of natural organic substances potentially hindering rt-pcr-based virus detection in large volumes of environmental water. | quantitative detection of pathogenic viruses in the environmental water is essential for the assessment of water safety. it is known that some of natural organic substances interfere with virus detection processes, i.e., nucleic acid extraction and reverse transcription-pcr. such substances are carried over into a sample after virus concentration. in this study, inhibitory substances in coastal water samples were characterized in view of their effects on efficiency of virus detection and propert ... | 2017 | 29165998 |
| comparison of three extraction methods to detect noroviruses in dairy products. | noroviruses (nov) are currently the most common cause of viral foodborne diseases and rt-qpcr is widely used for their detection in food because of its sensitivity, specificity and rapidity. the iso/ts (15216-1, 15216-2) procedures for detecting nov and hav in high-risk food categories such as shellfish, bottled water and vegetables were published in 2013. milk products are less implicated in foodborne viral outbreaks but they can be contaminated with fruit added to these products or by the food ... | 2017 | 27697160 |
| evaluation of survival of murine norovirus-1 during sauerkraut fermentation and storage under standard and low-sodium conditions. | sodium reduction strategies have raised a few concerns in regards to possible outbreaks in unpasteurised raw fermented vegetables. among potential outbreak agents, foodborne viruses are recognized as an important cause of food-borne illnesses. as most of them are acid-resistant, evaluation of the efficacy of lactic fermentation in inactivating enteric viruses must be considered to ensure the safety of these foods. in particular with the sodium reduction trend which could impair adequate fermenta ... | 0 | 26338124 |
| testing for human norovirus and recovery of process control in outbreak-associated produce items. | the development of rapid and sensitive detection methods for human noroviruses (hunov) in produce items is critical, especially with the recent rise in outbreaks associated with this food commodity. in this study, 50-g portions of various produce items linked to a norovirus outbreak (celery, cucumber, lettuce, grapes, and radish) were artificially inoculated with murine norovirus (mnv-1) and concentrated either by ultracentrifugation or polyethylene glycol (peg) precipitation after elution with ... | 2018 | 29280676 |
| a synergy effect of trisodium phosphate and ethanol on inactivation of murine norovirus 1 on lettuce and bell pepper. | 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 ... | 2015 | 26323270 |
| evidence of the internalization of animal caliciviruses via the roots of growing strawberry plants and dissemination to the fruit. | human norovirus (nov) is the leading cause of foodborne disease in the united states, and epidemiological studies have shown that fresh produce is one of the major vehicles for the transmission of human nov. however, the mechanisms of norovirus contamination and persistence in fresh produce are poorly understood. the objective of this study is to determine whether human nov surrogates, murine norovirus (mnv-1) and tulane virus (tv), can attach and become internalized and disseminated in strawber ... | 2015 | 25662970 |
| inactivation of norovirus by lemongrass essential oil using a norovirus surrogate system. | this study investigated the effect of lemongrass essential oil (lgeo) on the infectivity and viral replication of norovirus. murine norovirus 1 (mnv-1), a surrogate of human norovirus, was preincubated with lgeo and then used to infect raw 264.7 cells in a plaque reduction assay. lgeo exhibited a significant reduction in mnv-1 plaque formation in both time- and dose-dependent manners. the quantification of viral genome by quantitative real-time pcr showed similar results in line with those of th ... | 2017 | 28699786 |
| mechanisms of antiviral action of plant antimicrobials against murine norovirus. | 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 reducti ... | 2014 | 24907316 |
| inactivation of human norovirus genogroups i and ii and surrogates by free chlorine in postharvest leafy green wash water. | 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 genotype i (gi) ... | 2017 | 28887415 |
| attachment and localization of human norovirus and animal caliciviruses in fresh produce. | 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 romain ... | 2015 | 26188496 |
| norovirus cross-contamination during preparation of fresh produce. | infection with human norovirus (hunov) is considered a common cause of foodborne illness worldwide. foodborne hunov outbreaks may result from consumption of food contaminated by an infected food handler in the foodservice environment, in which bare-hand contact, lack of hand washing, and inadequate cleaning and disinfection are common contributing factors. the goal of this study was to examine cross-contamination of a hunov surrogate, murine norovirus (mnv-1), during common procedures used in pr ... | 2015 | 25590260 |
| internalization and dissemination of human norovirus and animal caliciviruses in hydroponically grown romaine lettuce. | 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 × 10(6) rna copies/ml of a human nov genog ... | 2012 | 22729543 |
| alcohols as surface disinfectants in healthcare settings. | isopropyl alcohol and ethyl alcohol have been used as low-level disinfectants in healthcare settings for many years. recent studies have found that ethyl alcohol inhibits protein synthesis in escherichia coli by direct effects on ribosomes and rna polymerase and that 60%-70% solutions have in vitro efficacy against murine norovirus, ebola virus, and several coronaviruses. alcohol prep pads or towelettes containing isopropyl or ethyl alcohol and water have been used primarily for disinfection of ... | 2018 | 29374503 |
| disinfection of waterborne viruses using silver nanoparticle-decorated silica hybrid composites in water environments. | silver nanoparticles (agnps) have been reported as an effective alternative for controlling a broad-spectrum of pathogenic viruses. we developed a micrometer-sized silica hybrid composite decorated with agnps (agnp-sio2) to prevent the inherent aggregation of agnps, and facilitated their recovery from environmental media after use. the production process had a high-yield, and fabrication was cost-effective. we evaluated the antiviral capabilities of ag30-sio2 particles against two model viruses, ... | 2017 | 29291562 |
| murine norovirus inhibits b cell development in the bone marrow of stat1-deficient mice. | noroviruses are a leading cause of gastroenteritis in humans and it was recently revealed that noroviruses can infect b cells. we demonstrate that murine norovirus (mnv) infection can significantly impair b cell development in the bone marrow in a signal transducer and activator of transcription 1 (stat1) dependent, but interferon signaling independent manner. we also show that mnv replication is more pronounced in the absence of stat1 in ex vivo cultured b cells. interestingly, using bone marro ... | 2017 | 29287229 |
| heat-denatured lysozyme could be a novel disinfectant for reducing hepatitis a virus and murine norovirus on berry fruit. | hepatitis a virus (hav) is well known worldwide as a causative virus of acute hepatitis. in recent years, numerous cases of hav infection caused by hav-contaminated berries have occurred around the world. because berries are often consumed without prior heating, reliable disinfection of the raw fruit is important in order to prevent hav outbreaks. previous studies have found that murine norovirus strain 1 (mnv-1) and human norovirus gii.4 were inactivated in heat-denatured lysozyme solution. in ... | 2017 | 29202339 |
| the enterovirus protease inhibitor rupintrivir exerts cross-genotypic anti-norovirus activity and clears cells from the norovirus replicon. | potent and safe inhibitors of norovirus replication are needed for the treatment and prophylaxis of norovirus infections. we here report that the in vitro anti-norovirus activity of the protease inhibitor rupintrivir is extended to murine noroviruses and that rupintrivir clears human cells from their norwalk replicon after only two passages of antiviral pressure. in addition, we demonstrate that rupintrivir inhibits the human norovirus (genogroup ii [gii]) protease and further explain the inhibi ... | 2014 | 24890597 |
| evaluation of the suitability of a plant virus, pepper mild mottle virus, as a surrogate of human enteric viruses for assessment of the efficacy of coagulation-rapid sand filtration to remove those viruses. | here, we evaluated the removal of three representative human enteric viruses - adenovirus (adv) type 40, coxsackievirus (cv) b5, and hepatitis a virus (hav) ib - and one surrogate of human caliciviruses - murine norovirus (mnv) type 1 - by coagulation-rapid sand filtration, using water samples from eight water sources for drinking water treatment plants in japan. the removal ratios of a plant virus (pepper mild mottle virus; pmmov) and two bacteriophages (ms2 and φx174) were compared with the re ... | 2018 | 29182907 |
| virucidal efficacy of peracetic acid for instrument disinfection. | various peracetic-acid (paa)-based products for processing flexible endoscopes on the market are often based on a two-component system including a cleaning step before the addition of paa as disinfectant. the peracetic acid concentrations in these formulations from different manufacturers are ranging from 400 to 1500 ppm (part per million). these products are used at temperatures between 20 °c and 37 °c. since information on the virus-inactivating properties of peracetic acid at different concen ... | 2017 | 29177047 |
| inactivation of murine norovirus and hepatitis a virus on fresh raspberries by gaseous ozone treatment. | raspberries are vulnerable products for which industrial treatment solutions ensuring both food safety and sensory quality are not easily applicable. raspberries have been associated with numerous foodborne outbreaks in recent decades. ozone has been proven effective as a drinking water treatment against pathogenic microorganisms. nevertheless, to date, little information is available regarding the effect of gaseous ozone on viruses in food matrices. a comparison of the effect of gaseous ozone o ... | 2018 | 29173615 |
| human norovirus and its surrogates induce plant immune response in arabidopsis thaliana and lactuca sativa. | 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 aci ... | 2017 | 28504573 |
| expression of ifnlr1 on intestinal epithelial cells is critical to the antiviral effects of interferon lambda against norovirus and reovirus. | lambda interferon (ifn-λ) has potent antiviral effects against multiple enteric viral pathogens, including norovirus and rotavirus, in both preventing and curing infection. because the intestine includes a diverse array of cell types, however, the cell(s) upon which ifn-λ acts to exert its antiviral effects is unclear. here, we sought to identify ifn-λ-responsive cells by generation of mice with lineage-specific deletion of the receptor for ifn-λ, ifnlr1 we found that expression of ifnlr1 on int ... | 2017 | 28077655 |
| inactivation efficiency and mechanism of uv-tio2 photocatalysis against murine norovirus using a solidified agar matrix. | human norovirus (hunov) is the primary cause of viral gastroenteritis worldwide. fresh blueberries are among high risk foods associated with norovirus related outbreaks. therefore, it is important to assess intervention strategies to reduce the risk of foodborne illness. the disinfection efficiency of decontamination methods is difficult to evaluate for fruits and vegetables due to an inconsistent degree of contamination and irregular surface characteristics. the inactivation efficiency and mech ... | 0 | 27705845 |
| viability of murine norovirus in salads and dressings and its inactivation using heat-denatured lysozyme. | 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 s ... | 0 | 27299671 |
| efficacy of oxidizing disinfectants at inactivating murine norovirus on ready-to-eat foods. | noroviruses are the leading cause of foodborne illness, and ready-to-eat foods are frequent vehicles of their transmission. studies of the disinfection of fruits and vegetables are becoming numerous. it has been shown that strong oxidizing agents are more effective than other chemical disinfectants for inactivating enteric viruses. the aim of this study was to evaluate the efficacy of oxidizing disinfectants (sodium hypochlorite, chloride dioxide and peracetic acid) at inactivating noroviruses o ... | 0 | 26686597 |
| virological quality of irrigation water sources and pepper mild mottle virus and tobacco mosaic virus as index of pathogenic virus contamination level. | irrigation water is a doorway for the pathogen contamination of fresh produce. we quantified pathogenic viruses [human adenoviruses, noroviruses of genogroups i and ii, group a rotaviruses, aichi virus 1 (aiv-1), enteroviruses (envs), and salivirus (saliv)] and examined potential index viruses [jc and bk polyomaviruses (jcpyvs and bkpyvs), pepper mild mottle virus (pmmov), and tobacco mosaic virus (tmv)] in irrigation water sources in the kathmandu valley, nepal. river, sewage, wastewater treatm ... | 2017 | 29098656 |
| interferon lambda (ifn-λ) efficiently blocks norovirus transmission in a mouse model. | human noroviruses are highly efficient in person to person transmission thus associated with explosive outbreaks of acute gastroenteritis. outbreak control is limited to disinfection and isolation measures. strategies to control the spread of noroviruses should be developed and models to study norovirus transmission will greatly facilitate this. here, a mouse-to-mouse transmission model, in which mice develop acute murine norovirus (mnv)-induced diarrhea, was used to explore the role of interfer ... | 2018 | 29080649 |
| membrane alterations induced by nonstructural proteins of human norovirus. | human noroviruses (hunov) are the most frequent cause of non-bacterial acute gastroenteritis worldwide, particularly genogroup ii genotype 4 (gii.4) variants. the viral nonstructural (ns) proteins encoded by the orf1 polyprotein induce vesical clusters harboring the viral replication sites. little is known so far about the ultrastructure of these replication organelles or the contribution of individual ns proteins to their biogenesis. we compared the ultrastructural changes induced by expression ... | 2017 | 29077760 |
| norovirus escape from broadly neutralizing antibodies is limited to allostery-like mechanisms. | ideal antiviral vaccines elicit antibodies (abs) with broad strain recognition that bind to regions that are difficult to mutate for escape. using 10 murine norovirus (mnv) strains and 5 human norovirus (hunov) virus-like particles (vlps), we identified monoclonal antibody (mab) 2d3, which broadly neutralized all mnv strains tested. importantly, escape mutants corresponding to this antibody were very slow to develop and were distal to those raised against our previously studied antibody, a6.2. t ... | 2017 | 29062895 |
| virucidal efficacy of food additive grade calcium hydroxide against surrogate of human norovirus. | an alkaline agent, namely, food additive grade calcium hydroxide (fdca(oh)2) in the solution, powder and suspension forms was evaluated as a virucidal agent, using a murine norovirus (mnv) as the surrogate for human norovirus. the main constituent of fdca(oh)2 is ca(oh)2, which has ph 13 in 0.17% solution. the results showed that 0.17% fdca(oh)2 solution could inactivate mnv within 30s even in the presence of organic materials (5% fetal bovine serum (fbs)). in a contaminated surface experiment, ... | 2018 | 29054741 |
| differentiation and protective capacity of virus-specific cd8+ t cells suggest murine norovirus persistence in an immune-privileged enteric niche. | noroviruses can establish chronic infections with active viral shedding in healthy humans but whether persistence is associated with adaptive immune dysfunction is unknown. we used genetically engineered strains of mouse norovirus (mnv) to investigate cd8+ t cell differentiation during chronic infection. we found that chronic infection drove mnv-specific tissue-resident memory (trm) cd8+ t cells to a differentiation state resembling inflationary effector responses against latent cytomegalovirus ... | 2017 | 29031786 |
| norovirus cell tropism is determined by combinatorial action of a viral non-structural protein and host cytokine. | cellular tropism during persistent viral infection is commonly conferred by the interaction of a viral surface protein with a host receptor complex. norovirus, the leading global cause of gastroenteritis, can be persistently shed during infection, but its in vivo cellular tropism and tropism determinants remain unidentified. using murine norovirus (mnov), we determine that a small number of intestinal epithelial cells (iecs) serve as the reservoir for fecal shedding and persistence. the viral no ... | 2017 | 28966054 |
| evaluation of air samplers and filter materials for collection and recovery of airborne norovirus. | the aim of this study was to identify the most efficient sampling method for quantitative pcr-based detection of airborne human norovirus (nov). | 2017 | 28921812 |
| reduction of human norovirus gi, gii, and surrogates by peracetic acid and monochloramine in municipal secondary wastewater effluent. | 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 ... | 2017 | 28910089 |
| application of gamma radiation for the reduction of norovirus and the quality stability in optimally ripened cabbage kimchi. | optimally ripened commercial cabbage kimchi is considered the main cause of enteric norovirus (nov) outbreaks in korea. this study investigated the effect of 1-10kgy gamma radiation on the inactivation of murine norovirus-1 (mnv-1; initial inoculum of 5-6log10pfu/ml), used as a human nov surrogate, in kimchi. the effects of gamma radiation on the ph and acidity were also examined to address the index of quality and fermentation, respectively. titers of mnv-1 significantly reduced (p<0.05) in kim ... | 2017 | 28888451 |
| the role of interferon in persistent viral infection: insights from murine norovirus. | persistent viral infections result from evasion or avoidance of sterilizing immunity, extend the timeframe of virus transmission, and can trigger disease. prior studies in mouse models of persistent infection have suggested that ineffective adaptive immune responses are necessary for persistent viral infection. however, recent work in the murine norovirus (mnv) model of persistent infection demonstrates that innate immunity can control both early and persistent viral replication independently of ... | 2017 | 29157967 |
| the major targets of acute norovirus infection are immune cells in the gut-associated lymphoid tissue. | noroviruses are the leading cause of food-borne gastroenteritis outbreaks and childhood diarrhoea globally, estimated to be responsible for 200,000 deaths in children each year 1-4 . thus, reducing norovirus-associated disease is a critical priority. development of vaccines and therapeutics has been hindered by the limited understanding of basic norovirus pathogenesis and cell tropism. while macrophages, dendritic cells, b cells and stem-cell-derived enteroids can all support infection of certai ... | 2017 | 29109476 |
| efficacy of ethanol against viruses in hand disinfection. | ethanol is used worldwide in healthcare facilities for hand rubbing. it has been reported to have a stronger and broader virucidal activity compared with propanols. the aim of this review was to describe the spectrum of virucidal activity of ethanol in solution or as commercially available products. a systematic search was conducted. studies were selected when they contained original data on reduction of viral infectivity from suspension tests (49 studies) and contaminated hands (17 studies). et ... | 2017 | 28882643 |
| recovery optimization and survival of the human norovirus surrogates feline calicivirus and murine norovirus on carpet. | carpets have been implicated in 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, we then developed a minispin column elution (msc) method, and lastly ... | 2017 | 28864657 |
| rna sequencing of murine norovirus-infected cells reveals transcriptional alteration of genes important to viral recognition and antigen presentation. | viruses inherently exploit normal cellular functions to promote replication and survival. one mechanism involves transcriptional control of the host, and knowledge of the genes modified and their molecular function can aid in understanding viral-host interactions. norovirus pathogenesis, despite the recent advances in cell cultivation, remains largely uncharacterized. several studies have utilized the related murine norovirus (mnv) to identify innate response, antigen presentation, and cellular ... | 2017 | 28848558 |
| inhibition of calcineurin or imp dehydrogenase exerts moderate to potent antiviral activity against norovirus replication. | norovirus is a major cause of acute gastroenteritis worldwide and has emerged as an important issue of chronic infection in transplantation patients. since no approved antiviral is available, we evaluated the effects of different immunosuppressants and ribavirin on norovirus and explored their mechanisms of action by using a human norovirus (hunv) replicon-harboring model and a surrogate murine norovirus (mnv) infectious model. the roles of the corresponding drug targets were investigated by gai ... | 2017 | 28807916 |
| noroviruses co-opt the function of host proteins vapa and vapb for replication via a phenylalanine-phenylalanine-acidic-tract-motif mimic in nonstructural viral protein ns1/2. | the norovirus genus contains important human pathogens, but the role of host pathways in norovirus replication is largely unknown. murine noroviruses provide the opportunity to study norovirus replication in cell culture and in small animals. the human norovirus nonstructural protein ns1/2 interacts with the host protein vamp-associated protein a (vapa), but the significance of the ns1/2-vapa interaction is unexplored. here we report decreased murine norovirus replication in vapa- and vapb-defic ... | 2017 | 28698274 |
| viral replication complexes are targeted by lc3-guided interferon-inducible gtpases. | all viruses with positive-sense rna genomes replicate on membranous structures in the cytoplasm called replication complexes (rcs). rcs provide an advantageous microenvironment for viral replication, but it is unknown how the host immune system counteracts these structures. here we show that interferon-gamma (ifng) disrupts the rc of murine norovirus (mnv) via evolutionarily conserved autophagy proteins and the induction of ifn-inducible gtpases, which are known to destroy the membrane of vacuol ... | 2017 | 28669671 |
| comparative inactivation of murine norovirus and ms2 bacteriophage by peracetic acid and monochloramine in municipal secondary wastewater effluent. | chlorination has long been used for disinfection of municipal wastewater (mww) effluent while the use peracetic acid (paa) has been proposed more recently in the united states. previous work has demonstrated the bactericidal effectiveness of paa and monochloramine in wastewater, but limited information is available for viruses, especially ones of mammalian origin (e.g., norovirus). therefore, a comparative assessment was performed of the virucidal efficacy of paa and monochloramine against murin ... | 2017 | 28165216 |
| recent advances in understanding noroviruses. | 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 bar ... | 2017 | 28163914 |
| virucidal efficacy of a sonicated hydrogen peroxide system (trophon® epr) following european and german test methods. | aim: the virucidal efficacy of an automated ultrasound probe disinfector (trophon® epr) was evaluated in a three step procedure according to european and german test methods. this system uses sonicated hydrogen peroxide mist (35%) at elevated temperature (50°c) in a closed chamber with control of all parameters within a 7 minute cycle. methods: in the first step of examination, the peroxide solution was tested in a quantitative suspension assay according to the guideline of deutsche vereinigung ... | 2017 | 28149707 |
| transcriptomic analysis of human norovirus ns1-2 protein highlights a multifunctional role in murine monocytes. | the gii.4 sydney 2012 strain of human norovirus (hunov) is a pandemic strain that is responsible for the majority of norovirus outbreaks in healthcare settings. the function of the non-structural (ns)1-2 protein from hunov is unknown. | 2017 | 28056773 |
| murine norovirus infection in brazilian animal facilities. | murine norovirus (mnv) is a single-stranded positive-sense rna virus of the caliciviridae family. mnv has been reported to infect laboratory mice with the ability to cause lethal infections in strains lacking components of the innate immune response. currently, mnv is considered the most prevalent infectious agent detected in laboratory mouse facilities. in this study, mice in 22 laboratory animal facilities within brazil were analyzed for mnv infection. using primers targeting a conserved regio ... | 2017 | 28049885 |
| norovirus polymerase fidelity contributes to viral transmission in vivo. | 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 replicat ... | 2017 | 27777985 |
| curcumin shows antiviral properties against norovirus. | phytochemicals provide environmentally friendly and relatively inexpensive natural products, which could potentially benefit public health by controlling human norovirus (hunov) infection. in this study, 18 different phytochemicals were evaluated for antiviral effects against norovirus using murine norovirus (mnv) as a model for norovirus biology. among these phytochemicals, curcumin (ccm) was the most potent anti-noroviral phytochemical, followed by resveratrol (rvt). in a cell culture infectio ... | 2016 | 27775614 |
| viral population changes during murine norovirus propagation in raw 264.7 cells. | laboratory adaptation of viruses is an essential technique for basic virology research, including the generation of attenuated vaccine strains, although the principles of cell adaptation remain largely unknown. deep sequencing of murine norovirus (munov) s7 during serial passages in raw264.7 cells showed that the frequencies of viral variants were altered more dynamically than previously reported. serial passages of the virus following two different multiplicity of infections gave rise to distin ... | 2017 | 28663743 |
| identification of amino acids within norovirus polymerase involved in rna binding and viral replication. | until recently, molecular studies on human norovirus (hunov), a major causative agent of gastroenteritis, have been hampered by the lack of an efficient cell culture system. murine norovirus-1 (mnv-1) has served as a surrogate model system for norovirus research, due to the availability of robust cell culture systems and reverse genetics. to identify amino acids involved in rna synthesis by the viral rna-dependent rna polymerase (ns7), we constructed ns7 mutants in which basic amino acids surrou ... | 2017 | 28640742 |
| minimizing bias in virally seeded water treatment studies: evaluation of optimal bacteriophage and mammalian virus preparation methodologies. | one key assumption impacting data quality in viral inactivation studies is that reduction estimates are not altered by the virus seeding process. however, seeding viruses often involves the inadvertent addition of co-constituents such as cell culture components or additives used during preparation steps which can impact viral reduction estimates by inducing non-representative oxidant demand in disinfection studies and fouling in membrane assessments. the objective of this study was therefore to ... | 2017 | 28616834 |