Xpert registered Norovirus Assay (Cepheid, Sunnyvale, CA) was compared with a laboratory-developed real-time RT-PCR assay for the detection of Norovirus GI and GII in hospitalized patients with acute ...gastroenteritis. The two assays showed a high level of concordance but Xpert registered Norovirus Assay allowed faster detection of Norovirus and a simpler sample handling.
Noroviruses (NoVs) constitute a major cause of gastroenteritis in Tunisia. One hundred and fourteen matched saliva and stool samples were collected from children (n = 114) suffering from acute ...gastroenteritis at the hospital of Monastir during the winter season 2011-2012. For 98 of 114 children, blood samples were collected for secretor genotyping. NoVs were associated with 36.8% (n = 42/114) of the gastroenteritis cases. The GII.3 genotype was the most common (69% of all NoVs). For patients who were phenotyped (n = 114) for human blood group antigens (HBGAs), the secretor and non-secretor phenotypes represented 79% and 21%, respectively. Of the NoV infections, 83% were detected in all ABO groups. Five GII.3 isolates, one GII.1 isolate and one GII.7 isolate were detected in Lewis-positive non-secretors, confirmed by genotyping of the FUT2 gene. Even though our data showed that GII.3 NoVs could infect non-secretors, no binding was observed with saliva and GII.3 baculovirus-expressed virus-like particles from the same symptomatic non-secretor individual. This suggests that other factors might also participate in NoV attachment in children and newborns.
We evaluated the virucidal efficacy of light-activated fluorinated TiO sub(2) 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-TiO sub(2) surfaces, while contact with the F-TiO sub(2) surface and exposure to residual UVA radiation of 10 muW cm super(-2) for 60 min resulted in infectivity reductions for the norovirus surrogates of 2-3 log sub(10). Infectivity reductions on pristine TiO sub(2) 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 12 h. 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-TiO sub(2) compared to pristine TiO sub(2) 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.
Noroviruses are genetically diverse RNA viruses associated with acute gastroenteritis in mammalian hosts. Phylogenetically, they can be segregated into different genogroups as well as P ...(polymerase)-groups and further into genotypes and P-types based on amino acid diversity of the complete VP1 gene and nucleotide diversity of the RNA-dependent RNA polymerase (RdRp) region of ORF1, respectively. In recent years, several new noroviruses have been reported that warrant an update of the existing classification scheme. Using previously described 2× standard deviation (sd) criteria to group sequences into separate clusters, we expanded the number of genogroups to 10 (GI-GX) and the number of genotypes to 48 (9 GI, 27 GII, 3 GIII, 2 GIV, 2 GV, 2 GVI and 1 genotype each for GVII, GVIII, GIX formerly GII.15 and GX). Viruses for which currently only one sequence is available in public databases were classified into tentative new genogroups (GNA1 and GNA2) and genotypes (GII.NA1, GII.NA2 and GIV.NA1) with their definitive assignment awaiting additional related sequences. Based on nucleotide diversity in the RdRp region, noroviruses can be divided into 60 P-types (14 GI, 37 GII, 2 GIII, 1 GIV, 2 GV, 2 GVI, 1 GVII and 1 GX), 2 tentative P-groups and 14 tentative P-types. Future classification and nomenclature updates will be based on complete genome sequences and will be coordinated and disseminated by the international norovirus classification-working group.
The design, synthesis, and evaluation of a series of dipeptidyl I--hydroxyphosphonates is reported. The synthesized compounds displayed high anti-norovirus activity in a cell-based replicon system, ...as well as high enzyme selectivity.
In order to adapt port rapid detection of food borne norovirus, presently we developed a new typed detection method based on F sub(0)F sub(1)-ATPase molecular motor biosensor. A specific probe was ...encompassed the conservative region of norovirus and F sub(0)F sub(1)-ATPase within chromatophore was constructed as a molecular motor biosensor through the " epsilon -subunit antibody-streptomycin-biotin-probe" system. Norovirus was captured based on probe-RNA specific binding. Our results demonstrated that the Limit of Quantification (LOQ) is 0.005 ng/mL for NV RNA and also demonstrated that this method possesses specificity and none cross-reaction for food borne virus. What's more, the experiment used this method could be accomplished in 1 h. We detected 10 samples by using this method and the results were consistent with RT-PCR results. Overall, based on F sub(0)F sub(1)-ATPase molecular motors biosensor system we firstly established a new typed detection method for norovirus detection and demonstrated that this method is sensitive and specific and can be used in the rapid detection for food borne virus.
Norovirus infections are a major cause of gastroenteritis, and outbreaks occur frequently. Several factors are currently increasing the challenge posed by norovirus infections to global health, ...notably the increasing number of infections in immunocompromised individuals, who are more susceptible to disease, and the globalization of the food industry, which enables large norovirus outbreaks to occur on an international scale. Furthermore, the rapid rate of the genetic and antigenic evolution of circulating noroviruses complicates the development of vaccines and therapies that are required to counter these challenges. In this Review, we describe recent advances in the study of the transmission, pathogenesis and evolution of human noroviruses, and consider the ongoing risk of norovirus outbreaks, together with the future prospects for therapeutics, in a rapidly changing world.
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