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1

Aw, Tiong Gim, Karina Yew-Hoong Gin, Lynette Lin Ean Oon, Eileen Xueqin Chen, and Chee Hoe Woo. "Prevalence and Genotypes of Human Noroviruses in Tropical Urban Surface Waters and Clinical Samples in Singapore." Applied and Environmental Microbiology 75, no. 15 (June 12, 2009): 4984–92. http://dx.doi.org/10.1128/aem.00489-09.

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ABSTRACT The prevalence and genotypes of norovirus genogroup I (GI) and GII in tropical urban catchment waters and an estuarine bay were studied. A comparative analysis was performed with environmental isolates of noroviruses and concurrently identified clinical isolates in Singapore during gastroenteritis outbreaks between August 2006 to January 2007. Noroviruses in environmental water samples were concentrated by using ultrafiltration techniques and then analyzed by reverse transcription-seminested PCR assay targeting the partial capsid region of noroviruses and DNA sequencing. Among the 60 water samples collected, noroviruses were detected in 43 (71.7%) of these samples. Of these 43 norovirus-positive samples, the coexistence of both GI and GII strains was identified in 23 (53.5%) water samples. The phylogenetic analysis revealed multiple genotypes of noroviruses GI and GII in environmental water samples. GI and GII strains were clustered into seven and nine (including two unclassified) genotypes, respectively. The major norovirus genotypes in environmental water samples were GI/2 and GI/4 and GII/4. Genotyping of the 21 norovirus-positive clinical samples showed that all of the strains belonged to the GII/4 cluster. The environmental and clinical norovirus GII/4 isolates showed high levels of nucleotide sequence identity to each other and to the novel GII/4 variant associated with global epidemics of gastroenteritis during 2006. This study suggests the emergence and circulation of multiple novel norovirus GI and GII genotypes in water environments. Further comprehensive surveillance of water environments for noroviruses and routine clinical reporting is warranted.
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2

Kirby, Amy E., Yvonne Kienast, Wanzhe Zhu, Jerusha Barton, Emeli Anderson, Melissa Sizemore, Jan Vinje, and Christine L. Moe. "Norovirus Seroprevalence among Adults in the United States: Analysis of NHANES Serum Specimens from 1999–2000 and 2003–2004." Viruses 12, no. 2 (February 5, 2020): 179. http://dx.doi.org/10.3390/v12020179.

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Norovirus is the most common cause of epidemic and endemic acute gastroenteritis. However, national estimates of the infection burden are challenging. This study used a nationally representative serum bank to estimate the seroprevalence to five norovirus genotypes including three GII variants: GI.1 Norwalk, GI.4, GII.3, GII.4 US95/96, GII.4 Farmington Hills, GII.4 New Orleans, and GIV.1 in the USA population (aged 16 to 49 years). Changes in seroprevalence to the three norovirus GII.4 variants between 1999 and 2000, as well as 2003 and 2004, were measured to examine the role of population immunity in the emergence of pandemic GII.4 noroviruses. The overall population-adjusted seroprevalence to any norovirus was 90.0% (1999 to 2000) and 95.9% (2003 to 2004). Seroprevalence was highest to GI.1 Norwalk, GII.3, and the three GII.4 noroviruses. Seroprevalence to GII.4 Farmington Hills increased significantly between the 1999 and 2000, as well as the 2003 and 2004, study cycles, consistent with the emergence of this pandemic strain. Seroprevalence to GII.4 New Orleans also increased over time, but to a lesser degree. Antibodies against the GIV.1 norovirus were consistently detected (population-adjusted seroprevalence 19.1% to 25.9%), with rates increasing with age. This study confirms the high burden of norovirus infection in US adults, with most adults having multiple norovirus infections over their lifetime.
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3

Sarmento, Sylvia Kahwage, Juliana da Silva Ribeiro de Andrade, Marize Pereira Miagostovich, and Tulio Machado Fumian. "Virological and Epidemiological Features of Norovirus Infections in Brazil, 2017–2018." Viruses 13, no. 9 (August 30, 2021): 1724. http://dx.doi.org/10.3390/v13091724.

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Noroviruses are considered an important cause of acute gastroenteritis (AGE) across all age groups. Here, we investigated the incidence of norovirus, genotypes circulation, and norovirus shedding in AGE stool samples from outpatients in Brazil. During a two-year period, 1546 AGE stool samples from ten Brazilian states were analyzed by RT-qPCR to detect and quantify GI and GII noroviruses. Positive samples were genotyped by dual sequencing using the ORF1/2 junction region. Overall, we detected norovirus in 32.1% of samples, with a massive predominance of GII viruses (89.1%). We also observed a significant difference between the median viral load of norovirus GI (3.4×105 GC/g of stool) and GII (1.9×107 GC/g). The most affected age group was children aged between 6 and 24 m old, and norovirus infection was detected throughout the year without marked seasonality. Phylogenetic analysis of partial RdRp and VP1 regions identified six and 11 genotype combinations of GI and GII, respectively. GII.4 Sydney[P16] was by far the predominant genotype (47.6%), followed by GII.2[P16], GII.4 Sydney[P31], and GII.6[P7]. We detected, for the first time in Brazil, the intergenogroup recombinant genotype GIX.1[GII.P15]. Our study contributes to the knowledge of norovirus genotypes circulation at the national level, reinforcing the importance of molecular surveillance programs for future vaccine designs.
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4

Santiso-Bellón, Cristina, Walter Randazzo, Alba Pérez-Cataluña, Susana Vila-Vicent, Roberto Gozalbo-Rovira, Carlos Muñoz, Javier Buesa, Gloria Sanchez, and Jesús Rodríguez Díaz. "Epidemiological Surveillance of Norovirus and Rotavirus in Sewage (2016–2017) in Valencia (Spain)." Microorganisms 8, no. 3 (March 24, 2020): 458. http://dx.doi.org/10.3390/microorganisms8030458.

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The aim of the present study was to perform the molecular epidemiology of rotaviruses and noroviruses detected in sewage samples from a large wastewater facility from the city of Valencia, Spain. A total of 46 sewage samples were collected over a one-year period (September 2016 to September 2017). Norovirus and rotavirus were detected and quantified by RT-qPCR, genotyped by semi-nested RT-PCR and further characterized by sequencing and phylogenetic analyses. Noroviruses and rotaviruses were widely distributed in sewage samples (69.6% for norovirus GI, 76.0% norovirus GII, and 71.7% rotaviruses) and viral loads varied from 4.33 to 5.75 log PCRU/L for norovirus GI, 4.69 to 6.95 log PCRU/L for norovirus GII, and 4.08 to 6.92 log PCRU/L for rotavirus. Overall, 87.5% (28/32) of GI noroviruses could not be genotyped, 6.25% (2/32) of the samples contained GI.2 genotype, and another 6.25% (2/32) were positive for GI.4 genotype. The most common genotype of GII noroviruses was GII.2 (40%, 14/35), followed by GII.6 (8.6%, 3/35) and GII.17 (5.7%, 2/35) while the remaining GII strains could not be typed (45.7%, 16/35). Rotavirus VP4 genotype P[8] was the only one found in 19 out of 33 rotavirus-positive samples (57.7%). G2 was the most prevalent rotavirus VP7 genotype (15.2%, 5/33) followed by G3, G9, and G12, with two positive samples for each genotype (6.1%, 2/33). In one sample both G1 and G2 genotypes were detected simultaneously (3%). The results presented here show that the surveillance of noroviruses and rotaviruses in sewage is useful for the study of their transmission in the population and their molecular epidemiology.
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5

Lee, Sung-Geun, Weon-Hwa Jheong, Chang-Il Suh, Sang-Hyun Kim, Joong-Bok Lee, Yong-Seok Jeong, GwangPyo Ko, Kyung Lib Jang, Gyu-Cheol Lee, and Soon-Young Paik. "Nationwide Groundwater Surveillance of Noroviruses in South Korea, 2008." Applied and Environmental Microbiology 77, no. 4 (December 23, 2010): 1466–74. http://dx.doi.org/10.1128/aem.01996-10.

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ABSTRACTTo inspect the norovirus contamination of groundwater in South Korea, a nationwide study was performed in the summer (June to August) and winter (October to December) of 2008. Three-hundred sites designated by the government ministry were inspected. Water samples were collected for analysis of water quality, microorganism content, and viral content. Water quality was assessed by temperature, pH, turbidity, residual chlorine, and nitrite nitrogen content. Microorganism contents were analyzed bacteria, total coliforms,Escherichia coli, and bacteriophage. Virus analyses included panenterovirus and norovirus. Two primer sets were used for the detection of norovirus genotypes GI and GII, respectively. Of 300 samples, 65 (21.7%) were norovirus positive in the summer and in 52 (17.3%) were norovirus positive in the winter. The genogroup GI noroviruses that were identified were GI-1, GI-2, GI-3, GI-4, GI-5, GI-6, and GI-8 genotypes; those in the GII genogroup were GII-4 and GII-Yuri genotypes. The analytic data showed correlative relationships between the norovirus detection rate and the following parameters: water temperature and turbidity in physical-chemical parameters and somatic phage in microbial parameters. It is necessary to periodically monitor waterborne viruses that frequently cause epidemic food poisoning in South Korea for better public health and sanitary conditions.
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6

Cannon, Jennifer L., Leslie Barclay, Nikail R. Collins, Mary E. Wikswo, Christina J. Castro, Laura Cristal Magaña, Nicole Gregoricus, Rachel L. Marine, Preeti Chhabra, and Jan Vinjé. "Genetic and Epidemiologic Trends of Norovirus Outbreaks in the United States from 2013 to 2016 Demonstrated Emergence of Novel GII.4 Recombinant Viruses." Journal of Clinical Microbiology 55, no. 7 (May 10, 2017): 2208–21. http://dx.doi.org/10.1128/jcm.00455-17.

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ABSTRACT Noroviruses are the most frequent cause of epidemic acute gastroenteritis in the United States. Between September 2013 and August 2016, 2,715 genotyped norovirus outbreaks were submitted to CaliciNet. GII.4 Sydney viruses caused 58% of the outbreaks during these years. A GII.4 Sydney virus with a novel GII.P16 polymerase emerged in November 2015, causing 60% of all GII.4 outbreaks in the 2015-2016 season. Several genotypes detected were associated with more than one polymerase type, including GI.3, GII.2, GII.3, GII.4 Sydney, GII.13, and GII.17, four of which harbored GII.P16 polymerases. GII.P16 polymerase sequences associated with GII.2 and GII.4 Sydney viruses were nearly identical, suggesting common ancestry. Other common genotypes, each causing 5 to 17% of outbreaks in a season, included GI.3, GI.5, GII.2, GII.3, GII.6, GII.13, and GII.17 Kawasaki 308. Acquisition of alternative RNA polymerases by recombination is an important mechanism for norovirus evolution and a phenomenon that was shown to occur more frequently than previously recognized in the United States. Continued molecular surveillance of noroviruses, including typing of both polymerase and capsid genes, is important for monitoring emerging strains in our continued efforts to reduce the overall burden of norovirus disease.
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7

BRUGGINK, L. D., N. L. DUNBAR, and J. A. MARSHALL. "Norovirus genotype diversity associated with gastroenteritis outbreaks in aged-care facilities." Epidemiology and Infection 143, no. 14 (February 27, 2015): 3064–68. http://dx.doi.org/10.1017/s095026881500031x.

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SUMMARYNoroviruses are a major cause of gastroenteritis. Vaccine strategies against norovirus are currently under consideration but depend on a detailed knowledge of the capsid genotypes. This study examined the incidence of norovirus outbreaks in residential aged-care facilities in Victoria, Australia over one year (2013) and documented the (capsid) norovirus genotypes associated with these outbreaks. It was found that 65·0% of 206 outbreaks tested were associated with norovirus infection, thereby showing norovirus to be the major cause of viral gastroenteritis in residential aged-care facilities. Fifteen capsid (open reading frame 2) genotypes were identified as follows: GI.2 (0·9%), GI.3 (1·8%), GI.4 (3·7%), GI.6 (0·9%), GI.7 (0·9%), GI.8 (0·9%), GII.1 (0·9%), GII.2 (0·9%), GII.3 (1·8%), GII.4 (2009-like) (0·9%), GII.4 (2012) (48·6%), GII.4 (2012-like) (16·5%), GII.4 (unknown) (9·2%), GII.5 (2·8%), GII.6 (0·9%), GII.7 (0·9%), GII.13 (6·4%) and an as yet unclassified GII genotype (0·9%). Although GII.4 was the most common norovirus capsid genotype detected, the great diversity of norovirus genotypes in the elderly indicates vaccination strategies for this demographic are not straightforward.
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8

Yuki, Yoshikazu, Shiho Kurokawa, Shintaro Sato, Ai Sasou, Naomi Matsumoto, Akio Suzuki, Naomi Sakon, et al. "A Heterodimeric Antibody Fragment for Passive Immunotherapy Against Norovirus Infection." Journal of Infectious Diseases 222, no. 3 (March 25, 2020): 470–78. http://dx.doi.org/10.1093/infdis/jiaa115.

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Abstract Human noroviruses cause an estimated 685 million infections and 200 000 deaths annually worldwide. Although vaccines against GII.4 and GI.1 genotypes are under development, no information is available regarding vaccines or monoclonal antibodies to other noroviral genotypes. Here, we developed 2 variable-domain llama heavy-chain antibody fragment (VHHs) clones, 7C6 and 1E4, against GII.4 and GII.17 human noroviruses, respectively. Although 7C6 cross-reacted with virus-like particles (VLPs) of GII.17, GII.6, GII.3, and GII.4, it neutralized only GII.4 norovirus. In contrast, 1E4 reacted with and neutralized only GII.17 VLPs. Both VHHs blocked VLP binding to human induced pluripotent stem cell-derived intestinal epithelial cells and carbohydrate attachment factors. Using these 2 VHHs, we produced a heterodimeric VHH fragment that neutralized both GII.4 and GII.17 noroviruses. Because VHH fragments are heat- and acid-stable recombinant monoclonal antibodies, the heterodimer likely will be useful for oral immunotherapy and prophylaxis against GII.4 and GII.17 noroviruses in young, elderly, or immunocompromised persons.
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9

Munjita, Samuel Munalula. "Current Status of Norovirus Infections in Children in Sub-Saharan Africa." Journal of Tropical Medicine 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/309648.

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Noroviruses are a leading cause of acute sporadic gastroenteritis worldwide. In Sub-Saharan Africa, information regarding norovirus infections in children is scarce. A systematic review of studies performed between 1993 and June 2015 was conducted to establish the genotypic distribution and prevalence of norovirus infections in children (≤17) in Sub-Saharan Africa. Analysis of data from 19 studies involving 8,399 samples from children with symptomatic and nonsymptomatic gastroenteritis revealed prevalence of 12.6% (range 4.6% to 32.4%). The prevalence of norovirus infections was higher in symptomatic children (14.2%) than asymptomatic children (9.2%). Genogroup II (GII) was the most prevalent genogroup accounting for 76.4% of all the reported norovirus infections. The rest of the infections were GI (21.7%) and GI/GII (1.9%). The most common genotypes were GII.4 (65.2%), GI.7 (33.3%), and GI.3 (21.3%). These statistics were calculated from studies carried out in 12 out of 48 Sub-Saharan African countries. Therefore, more studies involving several countries are required to determine fully the epidemiology of noroviruses and their contribution to childhood diarrhoea in Sub-Saharan Africa.
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10

Rossouw, Esmari, Marieke Brauer, Pieter Meyer, Nicolette M. du Plessis, Theunis Avenant, and Janet Mans. "Virus Etiology, Diversity and Clinical Characteristics in South African Children Hospitalised with Gastroenteritis." Viruses 13, no. 2 (January 30, 2021): 215. http://dx.doi.org/10.3390/v13020215.

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Background: Viral gastroenteritis remains a major cause of hospitalisation in young children. This study aimed to determine the distribution and diversity of enteric viruses in children ≤5 years, hospitalised with gastroenteritis at Kalafong Provincial Tertiary Hospital, Pretoria, South Africa, between July 2016 and December 2017. Methods: Stool specimens (n = 205) were screened for norovirus GI and GII, rotavirus, sapovirus, astrovirus and adenovirus by multiplex RT-PCR. HIV exposure and FUT2 secretor status were evaluated. Secretor status was determined by FUT2 genotyping. Results: At least one gastroenteritis virus was detected in 47% (96/205) of children. Rotavirus predominated (46/205), followed by norovirus (32/205), adenovirus (15/205), sapovirus (9/205) and astrovirus (3/205). Norovirus genotypes GI.3, GII.2, GII.3, GII.4, GII.7, GII.12, GII.21, and rotavirus strains G1P[8], G2P[4], G2P[6], G3P[4], G3P[8], G8P[4], G8P[6], G9P[6], G9P[8] and sapovirus genotypes GI.1, GI.2, GII.1, GII.4, GII.8 were detected; norovirus GII.4[P31] and rotavirus G3P[4] predominated. Asymptomatic norovirus infection (GI.3, GI.7, GII.4, GII.6, GII.13) was detected in 22% of 46 six-week follow up stools. HIV exposure (30%) was not associated with more frequent or severe viral gastroenteritis hospitalisations compared to unexposed children. Rotavirus preferentially infected secretor children (p = 0.143) and norovirus infected 78% secretors and 22% non-secretors. Conclusion: Rotavirus was still the leading cause of gastroenteritis hospitalisations, but norovirus caused more severe symptoms.
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Jung, James, Timothy Grant, Dennis R. Thomas, Chris W. Diehnelt, Nikolaus Grigorieff, and Leemor Joshua-Tor. "High-resolution cryo-EM structures of outbreak strain human norovirus shells reveal size variations." Proceedings of the National Academy of Sciences 116, no. 26 (June 10, 2019): 12828–32. http://dx.doi.org/10.1073/pnas.1903562116.

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Noroviruses are a leading cause of foodborne illnesses worldwide. Although GII.4 strains have been responsible for most norovirus outbreaks, the assembled virus shell structures have been available in detail for only a single strain (GI.1). We present high-resolution (2.6- to 4.1-Å) cryoelectron microscopy (cryo-EM) structures of GII.4, GII.2, GI.7, and GI.1 human norovirus outbreak strain virus-like particles (VLPs). Although norovirus VLPs have been thought to exist in a single-sized assembly, our structures reveal polymorphism between and within genogroups, with small, medium, and large particle sizes observed. Using asymmetric reconstruction, we were able to resolve a Zn2+metal ion adjacent to the coreceptor binding site, which affected the structural stability of the shell. Our structures serve as valuable templates for facilitating vaccine formulations.
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da Silva, Allegra Kyria, Jean-Claude Le Saux, Sylvain Parnaudeau, Monique Pommepuy, Menachem Elimelech, and Françoise S. Le Guyader. "Evaluation of Removal of Noroviruses during Wastewater Treatment, Using Real-Time Reverse Transcription-PCR: Different Behaviors of Genogroups I and II." Applied and Environmental Microbiology 73, no. 24 (October 12, 2007): 7891–97. http://dx.doi.org/10.1128/aem.01428-07.

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ABSTRACT Noroviruses, an important cause of gastroenteritis, are excreted by infected individuals and are therefore present in wastewater. We quantified norovirus genogroup I (GI) and GII in wastewater at different locations in France and evaluated removal by a range of treatment types, including basic (waste stabilization pond), current industry standard (activated sludge), and state-of-the-art (submerged membrane bioreactor) treatments. Noroviruses were quantified using real-time reverse transcription-PCR (rRT-PCR). Mengovirus was used as a virus extraction control, and internal controls were used to verify the level of GI and GII rRT-PCR inhibition. A total of 161 (81 influent and 79 effluent) samples were examined; GI and GII were detected in 43 and 88% of the influent samples, respectively, and in 24 and 14% of the effluent samples, respectively. Physicians in France report far more cases of GII than GI during outbreaks; thus, the frequent presence of GI was unexpected. The GI influent concentrations were more variable, the peak GI influent concentrations were higher than the peak GII influent concentrations at all four sites (up to 1 × 109 and 6 × 107 genome copies/liter, respectively), and the average positive influent concentrations of GI were higher than the average positive influent concentrations of GII. The maximum effluent breakthrough concentrations were 6 × 106 and 3 × 106 genome copies/liter for GI and GII, respectively, indicating that the four treatment systems studied decreased the norovirus contamination load in receiving waters.
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Montazeri, Naim, Dorothee Goettert, Eric C. Achberger, Crystal N. Johnson, Witoon Prinyawiwatkul, and Marlene E. Janes. "Pathogenic Enteric Viruses and Microbial Indicators during Secondary Treatment of Municipal Wastewater." Applied and Environmental Microbiology 81, no. 18 (July 10, 2015): 6436–45. http://dx.doi.org/10.1128/aem.01218-15.

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ABSTRACTPathogenic enteric viruses are responsible for a wide range of infections in humans, with diverse symptoms. Raw and partially treated wastewaters are major sources of environmental contamination with enteric viruses. We monitored a municipal secondary wastewater treatment plant (New Orleans, LA) on a monthly basis for norovirus (NoV) GI and GII and enterovirus serotypes using multiplex reverse transcription-quantitative PCR (RT-qPCR) and microbial indicators of fecal contamination using standard plating methods. Densities of indicator bacteria (enterococci, fecal coliforms, andEscherichia coli) did not show monthly or seasonal patterns. Norovirus GII was more abundant than GI and, along with enterovirus serotypes, increased in influent during fall and spring. The highest NoV GI density in influent was in the fall, reaching an average of 4.0 log10genomic copies/100 ml. Norovirus GI removal (0.95 log10) was lower than that for GII, enterovirus serotypes, and male-specific coliphages (1.48 log10) or for indicator bacteria (4.36 log10), suggesting higher resistance of viruses to treatment. Male-specific coliphages correlated with NoV GII densities in influent and effluent (r= 0.48 and 0.76, respectively) and monthly removal, indicating that male-specific coliphages can be more reliable than indicator bacteria to monitor norovirus GII load and microbial removal. Dominant norovirus genotypes were classified into three GI genotypes (GI.1, GI.3, and GI.4) and four GII genotypes (GII.3, GII.4, GII.13, and GII.21), dominated by GI.1 and GII.4 strains. Some of the seasonal and temporal patterns we observed in the pathogenic enteric viruses were different from those of epidemiological observations.
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BRUGGINK, L. D., J. M. MOSELEN, and J. A. MARSHALL. "Genotype analysis of noroviruses associated with gastroenteritis outbreaks in childcare centres, Victoria, Australia, 2012–2015." Epidemiology and Infection 145, no. 9 (April 11, 2017): 1933–41. http://dx.doi.org/10.1017/s0950268817000681.

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SUMMARYThe characteristics of norovirus outbreaks in children (0–5 years) in childcare centres in Victoria, Australia (2012–2015) were examined. The three most common open reading frame (ORF) 2 genotypes in childcare centre outbreaks were GII.4 (42%), GII.6 (21%) and GII.3 (14%); the remaining genotypes (GI.2, GI.3, GI.4, GI.8, GI.13, GII.1, GII.2, GII.7 and GII.13) each made up <10%. The GII.4 genotype was the only norovirus genotype seen in all 4 years of the study and was the most common genotype in 2012–2014 but in 2015 the most common genotype was GII.2. The GII.4 genotype was more common in children 0–2 years, whereas GII.2 and GII.7 were more common in children 4–5 years. ORF 1/ORF 2 recombinant forms identified were GII.P4_NewOrleans_2009/GII.4_Sydney_2012, GII.P12/GII.3, GII.Pb (GII.21)/GII.3, GII.Pe/GII.2, GII.Pe/GII.4_Sydney_2012 and GII.Pg/GII.1. The findings indicate that norovirus genotype prevalence patterns in children were influenced by the age of the children and the year in which the analysis was carried out. The majority of norovirus infections (84%) occurred after the first year of life so that vaccination before the age of one would appear to be the most efficacious.
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Zhang, Lifang, Yanxia Peng, Na Jiang, Lei Shi, Jieping Lin, Ping Wu, and Qingjun Pan. "Preparation and Evaluation of Combined Detection of Norovirus GI and GII: An Innovative Fluorescent Particles Test Strip." BioMed Research International 2018 (2018): 1–5. http://dx.doi.org/10.1155/2018/7862467.

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This study was designed to prepare and evaluate the sensitivity and specificity of a Norovirus GI and GII fluorescent particles combined detection test strip method. Using selected chromatographic materials and antibodies specific to Norovirus GI and GII, the Norovirus GI and GII fluorescent particles combined detection test strip (tested method) was prepared as a conventional double antibody sandwich. The samples assayed included cultured rotavirus and 465 specimens from patients with symptoms of gastrointestinal infection. Norovirus was detected using the tested method and a reference method (CerTest Norovirus GI-GII test card). The results indicated that the sensitivity of the tested method was 4 (for GI detection) or 8 times (for GII detection) greater than the reference method. Neither of the two methods cross-reacted with rotavirus and so on. For specimens, 29 were found to be negative by the reference method and positive by the tested method, and 8 were found to be negative by the tested method and positive by the reference method. Furthermore, a retesting of these samples by qPCR showed that 28 of the 29 were positive, and 3 of the 8 were positive. In summary, the Norovirus GI and GII fluorescent particles combined detection test strip was successfully prepared and had good detection performance.
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Schilling-Loeffler, Katja, Rachel Rodriguez, and Jacquelina Williams-Woods. "Target Affinity and Structural Analysis for a Selection of Norovirus Aptamers." International Journal of Molecular Sciences 22, no. 16 (August 18, 2021): 8868. http://dx.doi.org/10.3390/ijms22168868.

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Aptamers, single-stranded oligonucleotides that specifically bind a molecule with high affinity, are used as ligands in analytical and therapeutic applications. For the foodborne pathogen norovirus, multiple aptamers exist but have not been thoroughly characterized. Consequently, there is little research on aptamer-mediated assay development. This study characterized seven previously described norovirus aptamers for target affinity, structure, and potential use in extraction and detection assays. Norovirus-aptamer affinities were determined by filter retention assays using norovirus genotype (G) I.1, GI.7, GII.3, GII.4 New Orleans and GII.4 Sydney virus-like particles. Of the seven aptamers characterized, equilibrium dissociation constants for GI.7, GII.3, GII.4 New Orleans and GII.4 Sydney ranged from 71 ± 38 to 1777 ± 1021 nM. Four aptamers exhibited affinity to norovirus GII.4 strains; three aptamers additionally exhibited affinity toward GII.3 and GI.7. Aptamer affinity towards GI.1 was not observed. Aptamer structure analysis by circular dichroism (CD) spectroscopy showed that six aptamers exhibit B-DNA structure, and one aptamer displays parallel/antiparallel G-quadruplex hybrid structure. CD studies also showed that biotinylated aptamer structures were unchanged from non-biotinylated aptamers. Finally, norovirus aptamer assay feasibility was demonstrated in dot-blot and pull-down assays. This characterization of existing aptamers provides a knowledge base for future aptamer-based norovirus detection and extraction assay development and aptamer modification.
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Nakjarung, Kaewkanya, Ladaporn Bodhidatta, Pimmnapar Neesanant, Paphavee Lertsethtakarn, Orntipa Sethabutr, Ket Vansith, Chhour Y. Meng, Brett E. Swierczewski, and Carl J. Mason. "Molecular Epidemiology and Genetic Diversity of Norovirus in Young Children in Phnom Penh, Cambodia." Journal of Tropical Medicine 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/2707121.

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This study investigated the genetic diversity of noroviruses identified from a previous surveillance study conducted at the National Pediatric Hospital in Phnom Penh, Cambodia, from 2004 to 2006. In the previous study, 926 stool samples were collected from children aged 3–60 months with acute diarrhea (cases) and without diarrhea (controls) with reported 6.7% of cases and 3.2% of controls being positive for norovirus. The initial norovirus diagnostic assay was performed with real-time reverse transcription-polymerase chain reaction (real-time RT PCR) which also distinguished between genogroups I and II (GI and GII). Norovirus infection was most commonly detected in children aged 12–23 months in both cases and controls. Norovirus Genotyping Tool and phylogenetic analysis of partial sequences of the 3′ end of the RNA-dependent RNA Polymerase (RdRp) and the capsid domain region were employed to assign genotypes of the norovirus strains. GII.4 was the most predominant capsid genotype detected at 39.5% followed by GII.6 at 14.9%. The GII.4 Hunter 2004 variant was the predominant strain detected. Six RdRP/capsid recombinants including GII.P7/GII.6, GII.P7/GII.14, GII.P7/GII.20, GII.P12/GII.13, GII.P17/GII.16, and GII.P21/GII.3 were also identified. This study of norovirus infection in young children in Cambodia suggests genetic diversity of norovirus as reported worldwide.
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PUUSTINEN, L., V. BLAZEVIC, L. HUHTI, E. D. SZAKAL, A. HALKOSALO, M. SALMINEN, and T. VESIKARI. "Norovirus genotypes in endemic acute gastroenteritis of infants and children in Finland between 1994 and 2007." Epidemiology and Infection 140, no. 2 (April 14, 2011): 268–75. http://dx.doi.org/10.1017/s0950268811000549.

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SUMMARYNoroviruses are, after rotaviruses, the second most common causative agents of acute gastroenteritis in young children. We studied norovirus genotypes in faecal specimens collected from Finnish children followed-up prospectively in rotavirus vaccine trials. Almost 5000 faecal specimens collected from cases of acute gastroenteritis were examined using reverse transcriptase–PCR. A total of 1172 cases (25% of all acute gastroenteritis) were associated with noroviruses. Of these, 96% were genogroup GII. GII.4 was the most common genotype (46%) throughout the study period but the proportion of this genotype varied in different norovirus epidemic seasons. Additional norovirus genotypes detected were: GII.7 (15%), GII.3 (14%), GII.1 (9%), GII.b (7%), GII.2 (3%), and GI.3 (2%). GII.4 dominated during the following years: 1998–1999 (75%), 2002–2003 (88%) and 2006–2007 (98%) while recombinant genotype GII.b was dominant between 2003 and 2004 (83%). In conclusion, genotypes GII.4 and GIIb have emerged as predominant norovirus genotypes in endemic gastroenteritis affecting young infants and children in Finland.
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Wolf, Sandro, Wendy M. Williamson, Joanne Hewitt, Malet Rivera-Aban, Susan Lin, Andrew Ball, Paula Scholes, and Gail E. Greening. "Sensitive Multiplex Real-Time Reverse Transcription-PCR Assay for the Detection of Human and Animal Noroviruses in Clinical and Environmental Samples." Applied and Environmental Microbiology 73, no. 17 (July 6, 2007): 5464–70. http://dx.doi.org/10.1128/aem.00572-07.

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ABSTRACT In this study, we developed a triplex real-time reverse transcription-PCR (RT-PCR)-based method that detects and distinguishs between noroviruses belonging to genogroups I, II, and III and that targets the junction between the regions of open reading frame 1 (ORF1) and ORF2. This is the first assay to include all three genogroups and the first real-time RT-PCR-based method developed for the detection of bovine noroviruses. The assay was shown to be broadly reactive against a wide spectrum of norovirus genotypes, including GI/1 through GI/7, GII/1 through GII/8, GII/10, GII/12, and GII/17, in different matrices (including fecal specimens, treated and raw sewage, source water, and treated drinking water). The assay is highly sensitive, detecting low copy numbers of plasmids that carry the target sequence. A new bovine norovirus, Bo/NLV/Norsewood/2006/NZL, was identified by this assay and was further genetically characterized. The results implicate a broad range of possible applications, including clinical diagnostics, tracing of fecal contaminants, and due to its sensitivity and broad reactivity, environmental studies.
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Gonzalez, Mark D., L. Claire Langley, Blake W. Buchan, Matthew L. Faron, Melanie Maier, Kate Templeton, Kimberly Walker, et al. "Multicenter Evaluation of the Xpert Norovirus Assay for Detection of Norovirus Genogroups I and II in Fecal Specimens." Journal of Clinical Microbiology 54, no. 1 (November 11, 2015): 142–47. http://dx.doi.org/10.1128/jcm.02361-15.

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Norovirus is the most common cause of sporadic gastroenteritis and outbreaks worldwide. The rapid identification of norovirus has important implications for infection prevention measures and may reduce the need for additional diagnostic testing. The Xpert Norovirus assay recently received FDA clearance for the detection and differentiation of norovirus genogroups I and II (GI and GII), which account for the vast majority of infections. In this study, we evaluated the performance of the Xpert Norovirus assay with both fresh, prospectively collected (n= 914) and frozen, archived (n= 489) fecal specimens. A Centers for Disease Control and Prevention (CDC) composite reference method was used as the gold standard for comparison. For both prospective and frozen specimens, the Xpert Norovirus assay showed positive percent agreement (PPA) and negative percent agreement (NPA) values of 98.3% and 98.1% for GI and of 99.4% and 98.2% for GII, respectively. Norovirus prevalence in the prospective specimens (collected from March to May of 2014) was 9.9% (n= 90), with the majority of positives caused by genogroup II (82%,n= 74). The positive predictive value (PPV) of the Xpert Norovirus assay was 75% for GI-positive specimens, whereas it was 86.5% for GII-positive specimens. The negative predictive values (NPV) for GI and GII were 100% and 99.9%, respectively.
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Brown, Julianne R., Sunando Roy, Christopher Ruis, Erika Yara Romero, Divya Shah, Rachel Williams, and Judy Breuer. "Norovirus Whole-Genome Sequencing by SureSelect Target Enrichment: a Robust and Sensitive Method." Journal of Clinical Microbiology 54, no. 10 (August 3, 2016): 2530–37. http://dx.doi.org/10.1128/jcm.01052-16.

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Norovirus full-genome sequencing is challenging due to sequence heterogeneity among genomes. Previous methods have relied on PCR amplification, which is problematic due to primer design, and transcriptome sequencing (RNA-Seq), which nonspecifically sequences all RNA, including host and bacterial RNA, in stool specimens. Target enrichment uses a panel of custom-designed 120-mer RNA baits that are complementary to all publicly available norovirus sequences, with multiple baits targeting each position of the genome, which overcomes the challenge of primer design. Norovirus genomes are enriched from stool RNA extracts to minimize the sequencing of nontarget RNA. SureSelect target enrichment and Illumina sequencing were used to sequence full genomes from 507 norovirus-positive stool samples with reverse transcription–real-time PCR cycle threshold (CT) values of 10 to 43. Sequencing on an Illumina MiSeq system in batches of 48 generated, on average, 81% on-target reads per sample and 100% genome coverage with >12,000-fold read depth. Samples included genotypes GI.1, GI.2, GI.3, GI.6, GI.7, GII.1, GII.2, GII.3, GII.4, GII.5, GII.6, GII.7, GII.13, GII.14, and GII.17. When outliers were accounted for, we generated >80% genome coverage for all positive samples, regardless ofCTvalues. A total of 164 samples were tested in parallel with conventional PCR genotyping of the capsid shell domain; 164/164 samples were successfully sequenced, compared to 158/164 samples that were amplified by PCR. Four of the samples that failed capsid PCR analysis had low titers, which suggests that target enrichment is more sensitive than gel-based PCR. Two samples failed PCR due to primer mismatches; target enrichment uses multiple baits targeting each position, thus accommodating sequence heterogeneity among norovirus genomes.
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Wang, Anna, Qiong Huang, Lin Qin, Xianwu Zhong, Hui Li, Rongfeng Chen, Zhuang Wan, et al. "Epidemiological characteristics of asymptomatic Norovirus infection in a population from oyster (Ostrea rivularis Gould) farms in southern China." Epidemiology and Infection 146, no. 15 (August 22, 2018): 1955–64. http://dx.doi.org/10.1017/s0950268818002212.

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AbstractThe following paper investigates the prevalence and characteristics of asymptomatic norovirus infection in the population living around oyster farm sites. Two consecutive surveys were conducted from January 2014 to December 2014 and 4549 stool samples were screened during the same time period. The total asymptomatic infection rate was 4.04% (184/4549). Norovirus infection rate was 5.20% in oyster farming population which was significantly higher compared with non-farming population where the infection rate was 3.65% (χ2 = 5.49, P < 0.05). A total of 184 NoV positive samples were identified by real time-quantitative polymerase chain reaction (RT-qPCR) and semi-nested RT-PCR and 136 sequences were obtained. The sequences were clustered into 14 genotypes. GI strains were clustered into six genotypes, including GI.2, GI.3, GI.5, GI.6, GI.8 and GI.9; while GII strains were clustered into GII.2, GII.3, GII.4, GII.5, GII.6, GII.8 and GII.13. GI.9 and GII.17 were the predominant and most prevalent genotypes, respectively. The GII.17 genotype replaced GII.4 becoming the dominant genotype in the oyster farming area in 2014. To sum up, long-term monitoring of asymptomatic infection is crucial for the detection of new variant strains and for identifying outbreaks during the early stage.
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Shiota, Tomoyuki, Michio Okame, Sayaka Takanashi, Pattara Khamrin, Makiko Takagi, Kenji Satou, Yuichi Masuoka, et al. "Characterization of a Broadly Reactive Monoclonal Antibody against Norovirus Genogroups I and II: Recognition of a Novel Conformational Epitope." Journal of Virology 81, no. 22 (September 12, 2007): 12298–306. http://dx.doi.org/10.1128/jvi.00891-07.

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ABSTRACT Norovirus, which belongs to the family Caliciviridae, is one of the major causes of nonbacterial acute gastroenteritis in the world. The main human noroviruses are of genogroup I (GI) and genogroup II (GII), which were subdivided further into at least 15 and 18 genotypes (GI/1 to GI/15 and GII/1 to GII/18), respectively. The development of immunological diagnosis for norovirus had been hindered by the antigen specificity of the polyclonal antibody. Therefore, several laboratories have produced broadly reactive monoclonal antibodies, which recognize the linear GI and GII cross-reactive epitopes or the conformational GI-specific epitope. In this study, we characterized the novel monoclonal antibody 14-1 (MAb14-1) for further development of the rapid immunochromatography test. Our results demonstrated that MAb14-1 could recognize 15 recombinant virus-like particles (GI/1, 4, 8, and 11 and GII/1 to 7 and 12 to 15) and showed weak affinity to the virus-like particle of GI/3. This recognition range is the broadest of the existing monoclonal antibodies. The epitope for MAb14-1 was identified by fragment, sequence, structural, and mutational analyses. Both terminal antigenic regions (amino acid positions 418 to 426 and 526 to 534) on the C-terminal P1 domain formed the conformational epitope and were in the proximity of the insertion region (positions 427 to 525). These regions contained six amino acids responsible for antigenicity that were conserved among genogroup(s), genus, and Caliciviridae. This epitope mapping explained the broad reactivity and different titers among GI and GII. To our knowledge, we are the first group to identify the GI and GII cross-reactive monoclonal antibody, which recognizes the novel conformational epitope. From these data, MAb14-1 could be used further to develop immunochromatography.
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Mans. "Norovirus Infections and Disease in Lower‐Middleand Low‐Income Countries, 1997–2018." Viruses 11, no. 4 (April 10, 2019): 341. http://dx.doi.org/10.3390/v11040341.

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Noroviruses are a major cause of viral gastroenteritis. The burden of the norovirus in lowresourcesettings is not well‐established due to limited data. This study reviews the norovirusprevalence, epidemiology, and genotype diversity in lower‐middle‐income countries (LMIC) andin low‐income countries (LIC). PubMed was searched up to 14 January 2019 for norovirus studiesfrom all LIC and LMIC (World Bank Classification). Studies that tested gastroenteritis cases and/orasymptomatic controls for norovirus by reverse transcription‐polymerase chain reaction (RT‐PCR)were included. Sixty‐four studies, the majority on children <5 years of age, were identified, and 14%(95% confidence interval; CI 14–15, 5158/36,288) of the gastroenteritis patients and 8% (95% CI 7–9,423/5310) of healthy controls tested positive for norovirus. In LMIC, norovirus was detected in 15%(95% CI 15–16) of cases and 8% (95% CI 8–10) of healthy controls. In LIC, 11% (95% CI 10–12) ofsymptomatic cases and 9% (95% CI 8–10) of asymptomatic controls were norovirus positive.Norovirus genogroup II predominated overall. GII.4 was the predominant genotype in all settings,followed by GII.3 and GII.6. The most prevalent GI strain was GI.3. Norovirus causes a significantamount of gastroenteritis in low‐resource countries, albeit with high levels of asymptomaticinfection in LIC and a high prevalence of coinfections
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Kim, Jae-Seok, Hyun Soo Kim, Jungwon Hyun, Han-Sung Kim, and Wonkeun Song. "Molecular Epidemiology of Human Norovirus in Korea in 2013." BioMed Research International 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/468304.

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Norovirus is a major cause of acute gastroenteritis. The molecular epidemiology of norovirus exhibits temporal and geographical fluctuations, and new variants of the GII.4 genotype emerge every 2-3 years to cause global epidemics of acute gastroenteritis. We investigated GI and GII genotypes of human norovirus strains isolated from patients with acute gastroenteritis in Korea in 2013. Norovirus antigen test was performed on 2,980 fecal specimens from January to December 2013. RNA was extracted from norovirus antigen-positive fecal suspensions, and the norovirus capsid (VP1) and polymerase (RdRp) genes were characterized by RT-PCR and sequencing. Of the 230 genotyped strains, GII.4 (77.3%) was the most frequently observed capsid genotype, followed by GII.3 (6.1%) and GII.13 (3.9%). A norovirus GII.4 variant, GII.Pe/GII.4 Sydney 2012, was the most frequently found polymerase/capsid genotype (65.7%), followed by GII.P17/GII.17 (2.1%) and GII.P21/GII.3 (2.1%). Phylogenetic, similarity, and capsid epitope analyses of GII.Pe/GII.4 Sydney 2012 strains were performed. We concluded that the norovirus GII.4 variant, GII.Pe/GII.4 Sydney 2012, was the main cause of norovirus-related gastroenteritis in Korea in 2013.
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Batarseh, Einas, Lubna Hamdan, Bhinnata Piya, Laura Stewart, James D. Chappell, John Dunn, Daniel C. Payne, et al. "1101. Comparison of Clinical Characteristics and Demographics of GII.4 vs. Other GII Noroviruses Associated With Sporadic Acute Gastroenteritis in Children in Nashville, TN, 2012–2015." Open Forum Infectious Diseases 5, suppl_1 (November 2018): S330. http://dx.doi.org/10.1093/ofid/ofy210.936.

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Abstract Background Norovirus is a leading cause of acute gastroenteritis (AGE) in all age groups. Although at least 28 different genotypes infecting humans have been reported, most outbreaks over the last 15 years have been caused by genogroup II (GII) viruses, of which GII.4 viruses have caused more than 50%. Since clinical differences between different genotypes are poorly understood, we sought to compare clinical characteristics in children infected with GII.4 and non-GII.4 viruses. Methods Children between 15 days and 17 years who presented with AGE defined as diarrhea (≥3 loose stools in a 24 hour period) or vomiting (≥1 episodes in a 24 hour period) within 10 days duration were recruited in outpatient, emergency, and inpatient settings in Nashville, TN, during 2012–2015. Stool specimens were tested by RT-qPCR for GI and GII norovirus. Norovirus-positive specimens were genotyped by sequencing of a partial region of the capsid gene. In this study, we excluded children infected with GI, mixed GI/GII and non-typeable GII viruses. Results Of 3,705 AGE subjects enrolled, 2,892 (78%) specimens were collected, 637 (22%) tested norovirus-positive (567 [89%] GII, 62 [10%] GI, and 8 [1%] mixed GI/GII). Of the 567 GII viruses, 461 (81%) were able to be genotyped and of those 238/461 (51.6%) were typed as GII.4 and 223/461 (48.3%) were typed as other GII genotypes (non-GII.4, primarily GII.3 [65/ 461, 14.1%], GII.6 [48/461, 10.4%] and GII.7 [36/461, 7.8%]). Over three AGE seasons, GII.4 represented 64/117 (54%), 79/178 (44%), and 71/166 (57%), of the GII infections, respectively. Compared with non-GII.4 subjects, GII.4 subjects were more likely to be younger (15.5 vs. 21.3 months, P &lt; 0.01), and less likely to attend daycare (23% vs. 39%, P &lt; 0.01). GII.4 subjects also were more likely to present with diarrhea (75% vs. 57%, P &lt; 0.01) and had higher median modified Vesikari score (7 vs. 6, P &lt; 0.01). Conclusion Children infected with GII.4 viruses were younger, less likely to attend child care, more likely to present with diarrhea, and had a more severe illness compared with those with non-GII.4 infections. These data provide important information on the genotype distribution of norovirus in children with AGE in Tennessee and highlight GII.4 as the most prevalent strain. Disclosures N. Halasa, sanofi pasteur: Investigator, Research support. GSK: Consultant, Consulting fee. Moderna: Consultant, Consulting fee.
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Teixeira, Dielle Monteiro, Paula Katharine de Pontes Spada, Lena Líllian Canto de Sá Morais, Tulio Machado Fumian, Ian Carlos Gomes de Lima, Darleise de Souza Oliveira, Renato da Silva Bandeira, et al. "Norovirus genogroups I and II in environmental water samples from Belém city, Northern Brazil." Journal of Water and Health 15, no. 1 (November 7, 2016): 163–74. http://dx.doi.org/10.2166/wh.2016.275.

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This study investigated the presence of norovirus (NoV) GI and GII in environmental samples from the northern region of Brazil. Water samples were collected monthly (November 2008/October 2010) from different sources and sewage and concentrated by the adsorption-elution method. The NoV investigation used molecular methods followed by sequencing reactions. The general positivity for NoV was 33.9% (57/168). Considering the results obtained only in the semi-nested RT-PCR (reverse transcription polymerase chain reaction) and only in the TaqMan® real-time PCR, the rates were 26.8% (45/168) and 27.4% (46/168), respectively, being for NoV GI 22.2% (10/45) and 19.6% (9/46); for GII 17.8% (8/45) and 15.2% (7/46); and for GI + GII 60% (27/45) and 65.2% (30/46), respectively. Different GI (GI.1, GI.4, GI.7 and GI.8) and GII (GII.4, GII.6, GII.9, GII.12 and GII.14) genotypes were detected. These results demonstrated the NoV was disseminated in the waters of Belém city due to a lack of sanitation that allowed the discharge of contaminated effluents into these aquatic ecosystems.
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Crawford, Sue E., Nadim Ajami, Tracy Dewese Parker, Noritoshi Kitamoto, Katsuro Natori, Naokazu Takeda, Tomoyuki Tanaka, Baijun Kou, Robert L. Atmar, and Mary K. Estes. "Mapping Broadly Reactive Norovirus Genogroup I and II Monoclonal Antibodies." Clinical and Vaccine Immunology 22, no. 2 (November 26, 2014): 168–77. http://dx.doi.org/10.1128/cvi.00520-14.

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ABSTRACTNoroviruses 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.
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ZHOU, N., H. ZHANG, X. LIN, P. HOU, S. WANG, Z. TAO, Z. BI, and A. XU. "A waterborne norovirus gastroenteritis outbreak in a school, eastern China." Epidemiology and Infection 144, no. 6 (October 20, 2015): 1212–19. http://dx.doi.org/10.1017/s0950268815002526.

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SUMMARYIn late 2014, a gastroenteritis outbreak occurred in a school in Shandong Province, eastern China. Hundreds of individuals developed the symptoms of diarrhoea and vomiting. Epidemiological investigation showed that food consumption was not linked to this outbreak, and unboiled direct drinking water was identified as the independent risk factor with a relative risk of 1·37 (95% confidence interval 1·03–1·83). Furthermore, examination of common bacterial and viral gastroenteritis pathogens was conducted on different specimens. Norovirus GI.1, GI.2, GI.6, GII.4, GII.6 and GII.13 were detected in clinical specimens and a water sample. GII.4 sequences between clinical specimens and the water sample displayed a close relationship and belonged to GII.4 variant Sydney 2012. These results indicate that direct drinking water contaminated by norovirus was responsible for this gastroenteritis outbreak. This study enriches our knowledge of waterborne norovirus outbreaks in China, and presents valuable prevention and control practices for policy-makers. In future, strengthened surveillance and supervision of direct drinking-water systems is needed.
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Malm, Maria, Timo Vesikari, and Vesna Blazevic. "Simultaneous Immunization with Multivalent Norovirus VLPs Induces Better Protective Immune Responses to Norovirus than Sequential Immunization." Viruses 11, no. 11 (November 2, 2019): 1018. http://dx.doi.org/10.3390/v11111018.

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Human noroviruses (NoVs) are a genetically diverse, constantly evolving group of viruses. Here, we studied the effect of NoV pre-existing immunity on the success of NoV vaccinations with genetically close and distant genotypes. A sequential immunization as an alternative approach to multivalent NoV virus-like particles (VLPs) vaccine was investigated. Mice were immunized with NoV GI.3, GII.4-1999, GII.17, and GII.4 Sydney as monovalent VLPs or as a single tetravalent mixture combined with rotavirus VP6-protein. Sequentially immunized mice were primed with a trivalent vaccine candidate (GI.3 + GII.4-1999 + VP6) and boosted, first with GII.17 and then with GII.4 Sydney VLPs. NoV serum antibodies were analyzed. Similar NoV genotype-specific immune responses were induced with the monovalent and multivalent mixture immunizations, and no immunological interference was observed. Multivalent immunization with simultaneous mix was found to be superior to sequential immunization, as sequential boost induced strong blocking antibody response against the distant genotype (GII.17), but not against GII.4 Sydney, closely related to GII.4-1999, contained in the priming vaccine. Genetically close antigens may interfere with the immune response generation and thereby immune responses may be differently formed depending on the degree of NoV VLP genotype identity.
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Nahar, Shamsun, Mokibul Hassan Afrad, Noorjahan Begum, Feroz Al-Mamun, Azadul Kabir Sarker, Sumon Kumar Das, Abu SG Faruque, et al. "High prevalence of noroviruses among hospitalized diarrheal patients in Bangladesh, 2011." Journal of Infection in Developing Countries 7, no. 11 (November 15, 2013): 892–96. http://dx.doi.org/10.3855/jidc.2944.

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Introduction: Norovirus is not usually investigated in diarrheal patients in Bangladesh which may account for the many cases where no pathogens are identified. Methodology: Stool specimens collected from diarrheal patients from three hospitals in Bangladesh during 2011 were investigated for norovirus RNA using real-time RT-PCR assay with norovirus type specific primers and probes. Results: Of the 257 stool specimens tested, 28.4 % were norovirus positive. GII (71.2%) was the predominant strain followed by GI (20.5%), GI+GII (6.8%) and GIV (1.4%). Half of the norovirus positive stools (n=37) were co-infected with other pathogens. Conclusion: Continued surveillance of norovirus together with other viral and bacterial pathogens in hospitalized gastroenteritis patients as well as in the community will further elucidate the role and burden of different pathogens in diarrheal diseases.
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MANS, J., R. NETSHIKWETA, M. MAGWALIVHA, W. B. VAN ZYL, and M. B. TAYLOR. "Diverse norovirus genotypes identified in sewage-polluted river water in South Africa." Epidemiology and Infection 141, no. 2 (March 21, 2012): 303–13. http://dx.doi.org/10.1017/s0950268812000490.

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SUMMARYThis study aimed to assess norovirus (NoV) contamination and genotype diversity in surface water in Gauteng, South Africa. Between January 2008 and December 2010, three rivers, namely Klip, Suikerbosrant, and Rietspruit were monitored for NoV genogroup (G)I and GII. Viruses were recovered using the glass wool adsorption-elution technique and detected by real-time reverse transcription–polymerase chain reaction. From 2008 to 2010, NoVs were detected in 66% (70/106) of Klip river samples. The Rietspruit and Suikerbosrant rivers were contaminated with NoV in 95% (20/21) and 21% (5/24) of samples, respectively. NoV-positive samples comprised of 33% GI, 29% GII and 38% of both GI and GII strains. Based on partial capsid gene analysis (region C), 16 NoV genotypes (6 GI, 10 GII) were identified. The major genotypes detected were GI.4, GI.5 and GII.4. These rivers could be a potential source of NoV infection for communities using the water for domestic or recreational purposes.
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MANS, J., T. Y. MURRAY, S. NADAN, R. NETSHIKWETA, N. A. PAGE, and M. B. TAYLOR. "Norovirus diversity in children with gastroenteritis in South Africa from 2009 to 2013: GII.4 variants and recombinant strains predominate." Epidemiology and Infection 144, no. 5 (September 16, 2015): 907–16. http://dx.doi.org/10.1017/s0950268815002150.

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SUMMARYFrom 2009 to 2013 the diversity of noroviruses (NoVs) in children (⩽5 years) hospitalized with gastroenteritis in South Africa was investigated. NoVs were genotyped based on nucleotide sequence analyses of partial RNA-dependent RNA polymerase (RdRp) and capsid genes. Seventeen RdRp genotypes (GI.P2, GI.P3, GI.P6, GI.P7, GI.P not assigned (NA), GI.Pb, GI.Pf, GII.P2, GII.P4, GII.P7, GII.P13, GII.P16, GII.P21, GII.Pc, GII.Pe, GII.Pg, GII.PNA) and 20 capsid genotypes (GI.1, GI.2, GI.3, GI.5, GI.6, GI.7, GI.NA, GII.1, GII.2, GII.3, GII.4, GII.6, GII.7, GII.10, GII.12, GII.13, GII.14, GII.16, GII.17, GII.21) were identified. The combined RdRp/capsid genotype was determined for 275 GII strains. Fifteen confirmed recombinant NoV strains circulated during the study period. NoV GII.P4/GII.4 (47%) and GII.Pe/GII.4 (18%) predominated, followed by GII.PNA/GII.3 (10%) and GII.P21/GII.3 (7%). Other prevalent strains included GII.Pg/GII.12 (6%) and GII.Pg/GII.1 (3%). Two novel recombinants, GII.Pg/GII.2 and GII.Pg/GII.10 were identified. In 2013 the replacement of GII.4 New Orleans 2009 and GII.P21/GII.3, which predominated during the early part of the study, with GII.4 Sydney 2012 and GII.PNA/GII.3 was observed. This study presents the most comprehensive recent data on NoV diversity in Africa.
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Malm, Maria, Kirsi Tamminen, Suvi Lappalainen, Hanni Uusi-Kerttula, Timo Vesikari, and Vesna Blazevic. "Genotype Considerations for Virus-Like Particle-Based Bivalent Norovirus Vaccine Composition." Clinical and Vaccine Immunology 22, no. 6 (April 22, 2015): 656–63. http://dx.doi.org/10.1128/cvi.00015-15.

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ABSTRACTNorovirus (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.
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Ritchie, Arabela, Armando Hung, and Muriel Gómez-Sánchez. "Detección de Norovirus GI Y GII en muestras de agua del Río Piura mediante la técnica de RT-PCR en tiempo real." Salud y Tecnología Veterinaria 6, no. 2 (February 15, 2019): 47. http://dx.doi.org/10.20453/stv.v6i2.3458.

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Los Norovirus (NoV) son una de las causas más frecuentes de infecciones gastrointestinales agudas en humanos y un problema de salud importante en países en desarrollo. El objetivo del estudio fue detectar la presencia del Norovirus GI y GII en muestras de agua del Rio Piura mediante la concentración del virus en agua y RT-PCR en tiempo real. Para ello se recolectaron muestras de agua en botellas estériles en tres (3) puntos determinados del río, cada 15 días, desde mayo hasta Setiembre del 2013. Se obtuvo 20.8% (5/24) de muestras positivas para Norovirus GI mediante la técnica de RT-PCR en tiempo real. Ninguna de las muestras dio positivo a Norovirus GII. Este es el primer reporte de Norovirus GI en muestras de agua del Rio Piura. Los métodos propuestos podrían ser utilizados como herramienta para la investigación de patógenos en aguas del Rio Piura y la Bahía de Sechura.
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36

Chhabra, Preeti, Miranda de Graaf, Gabriel I. Parra, Martin Chi-Wai Chan, Kim Green, Vito Martella, Qiuhong Wang, et al. "Updated classification of norovirus genogroups and genotypes." Journal of General Virology 100, no. 10 (October 1, 2019): 1393–406. http://dx.doi.org/10.1099/jgv.0.001318.

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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 49 (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.
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Fardah Athiyyah, Alpha, Katsumi Shigemura, Koichi Kitagawa, Nazara Agustina, Andy Darma, Reza Ranuh, Dadik Raharjo, Toshiro Shirakawa, Masato Fujisawa, and Subijanto Marto Sudarmo. "Clinical manifestation of norovirus infection in children aged less than five years old admitted with acute diarrhea in Surabaya, Indonesia: a cross-sectional study." F1000Research 8 (March 9, 2020): 2130. http://dx.doi.org/10.12688/f1000research.21069.3.

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Background: The objective of this study was to investigate the clinical manifestation of norovirus infection between norovirus genogroup and severity of acute diarrhea in pediatric patients at the Dr. Soetomo Hospital, Surabaya, Indonesia. Methods: This cross-sectional study involved 31 participants aged 1-60 months admitted to the hospital with acute diarrhea from April 2012 to March 2013. Norovirus genogroups (GI and II) were identified from patient stool using reverse transcription polymerase chain reaction (RT-PCR). Severity was measured using the Ruuska and Vesikari scoring system. Results: In total, 94 stool samples were obtained, of which 31 (19%) were norovirus positive. Norovirus GI was found in one sample with mild diarrhea. Norovirus GII was found in 30 samples (96.8%); one sample with mild diarrhea (3.3%), 20 samples with moderate diarrhea (66.7%), and nine samples with severe diarrhea (30%). Conclusion: Norovirus GII was the most prevalent cause of acute diarrhea and 30% of the cases manifested as severe diarrhea.
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Shirato, Haruko, Satoko Ogawa, Hiromi Ito, Takashi Sato, Akihiko Kameyama, Hisashi Narimatsu, Zheng Xiaofan, et al. "Noroviruses Distinguish between Type 1 and Type 2 Histo-Blood Group Antigens for Binding." Journal of Virology 82, no. 21 (August 13, 2008): 10756–67. http://dx.doi.org/10.1128/jvi.00802-08.

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ABSTRACT Norovirus (NoV) is a causative agent of acute gastroenteritis. NoV binds to histo-blood group antigens (HBGAs), namely, ABH antigens and Lewis (Le) antigens, in which type 1 and type 2 carbohydrate core structures constitute antigenically distinct variants. Norwalk virus, the prototype strain of norovirus, binds to the gastroduodenal junction, and this binding is correlated with the presence of H type 1 antigen but not with that of H type 2 antigen (S. Marionneau, N. Ruvoen, B. Le Moullac-Vaidye, M. Clement, A. Cailleau-Thomas, G. Ruiz-Palacois, P. Huang, X. Jiang, and J. Le Pendu, Gastroenterology 122:1967-1977, 2002). It has been unknown whether NoV distinguishes between the type 1 and type 2 chains of A and B antigens. In this study, we synthesized A type 1, A type 2, B type 1, and B type 2 pentasaccharides in vitro and examined the function of the core structures in the binding between NoV virus-like particles (VLPs) and HBGAs. The attachment of five genogroup I (GI) VLPs from 5 genotypes and 11 GII VLPs from 8 genotypes, GI/1, GI/2, GI/3, GI/4, GI/8, GII/1, GII/3, GII/4, GII/5, GII/6, GII/7, GII/12, and GII/14, to ABH and Le HBGAs was analyzed by enzyme-linked immunosorbent assay-based binding assays and Biacore analyses. GI/1, GI/2, GI/3, GI/4, GI/8, and GII/4 VLPs were more efficiently bound to A type 2 than A type 1, and GI/8 and GII/4 VLPs were more efficiently bound to B type 2 than B type 1, indicating that NoV VLPs distinguish between type 1 and type 2 carbohydrates. The dissociation of GII/4 VLPs from B type 1 was slower than that from B type 2 in the Biacore experiments; moreover, the binding to B type 1 was stronger than that to B type 2 in the ELISA experiments. These results indicated that the type 1 carbohydrates bind more tightly to NoV VLPs than the type 2 carbohydrates. This property may afford NoV tissue specificity. GII/4 is known to be a global epidemic genotype and binds to more HBGAs than other genotypes. This characteristic may be linked with the worldwide transmission of GII/4 strains. GI/2, GI/3, GI/4, GI/8, GII/4, and GII/7 VLPs bound to Lea expressed by nonsecretors, suggesting that NoV can infect individuals regardless of secretor phenotype. Overall, our results indicated that HBGAs are important factors in determining tissue specificity and the risk of transmission.
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MATTHEWS, J. E., B. W. DICKEY, R. D. MILLER, J. R. FELZER, B. P. DAWSON, A. S. LEE, J. J. ROCKS, et al. "The epidemiology of published norovirus outbreaks: a review of risk factors associated with attack rate and genogroup." Epidemiology and Infection 140, no. 7 (March 27, 2012): 1161–72. http://dx.doi.org/10.1017/s0950268812000234.

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SUMMARYThe purpose of this study was to examine global epidemiological trends in human norovirus (NoV) outbreaks by transmission route and setting, and describe relationships between these characteristics, viral attack rates, and the occurrence of genogroup I (GI) or genogroup II (GII) strains in outbreaks. We analysed data from 902 reverse transcriptase–polymerase chain reaction-confirmed, human NoV outbreaks abstracted from a systematic review of articles published from 1993 to 2011 and indexed under the terms ‘norovirus’ and ‘outbreak’. Multivariate regression analyses demonstrated that foodservice and winter outbreaks were significantly associated with higher attack rates. Foodborne and waterborne outbreaks were associated with multiple strains (GI+GII). Waterborne outbreaks were significantly associated with GI strains, while healthcare-related and winter outbreaks were associated with GII strains. These results identify important trends for epidemic NoV detection, prevention, and control.
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40

Fardah Athiyyah, Alpha, Katsumi Shigemura, Koichi Kitagawa, Nazara Agustina, Andy Darma, Reza Ranuh, Dadik Raharjo, Toshiro Shirakawa, Masato Fujisawa, and Subijanto Marto Sudarmo. "Norovirus genogroup correlation with acute diarrhea severity in Indonesian pediatric patients aged 1-60 months: a cross-sectional study." F1000Research 8 (December 20, 2019): 2130. http://dx.doi.org/10.12688/f1000research.21069.1.

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Background: The objective of this study was to investigate the correlation between norovirus genogroup and severity of acute diarrhea in pediatric patients at the Dr. Soetomo Hospital, Surabaya, Indonesia. Methods: This cross-sectional study involved 31 participants aged 1-60 months admitted to the hospital with acute diarrhea from April 2012 to March 2013. Norovirus genogroups (GI and II) were identified from patient stool using reverse transcription polymerase chain reaction (RT-PCR). Severity was measured using the Ruuska and Vesikari scoring system. Results: In total, 91 stool samples were obtained, of which 31 (19%) were norovirus positive. Norovirus GI was found in one sample with mild diarrhea. Norovirus GII was found in 30 samples (96.8%); one sample with mild diarrhea (3.3%), 20 samples with moderate diarrhea (66.7%), and nine samples with severe diarrhea (30%). Conclusion: Norovirus GII was the most prevalent cause of acute diarrhea and 30% of the cases manifested as severe diarrhea.
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41

Fardah Athiyyah, Alpha, Katsumi Shigemura, Koichi Kitagawa, Nazara Agustina, Andy Darma, Reza Ranuh, Dadik Raharjo, Toshiro Shirakawa, Masato Fujisawa, and Subijanto Marto Sudarmo. "Norovirus genogroup correlation with acute diarrhea severity in Indonesian pediatric patients aged 1-60 months: a cross-sectional study." F1000Research 8 (February 14, 2020): 2130. http://dx.doi.org/10.12688/f1000research.21069.2.

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Background: The objective of this study was to investigate the correlation between norovirus genogroup and severity of acute diarrhea in pediatric patients at the Dr. Soetomo Hospital, Surabaya, Indonesia. Methods: This cross-sectional study involved 31 participants aged 1-60 months admitted to the hospital with acute diarrhea from April 2012 to March 2013. Norovirus genogroups (GI and II) were identified from patient stool using reverse transcription polymerase chain reaction (RT-PCR). Severity was measured using the Ruuska and Vesikari scoring system. Results: In total, 91 stool samples were obtained, of which 31 (19%) were norovirus positive. Norovirus GI was found in one sample with mild diarrhea. Norovirus GII was found in 30 samples (96.8%); one sample with mild diarrhea (3.3%), 20 samples with moderate diarrhea (66.7%), and nine samples with severe diarrhea (30%). Conclusion: Norovirus GII was the most prevalent cause of acute diarrhea and 30% of the cases manifested as severe diarrhea.
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42

Mathew, Shilu, Khalid Alansari, Maria K. Smatti, Hassan Zaraket, Asmaa A. Al Thani, and Hadi M. Yassine. "Epidemiological, Molecular, and Clinical Features of Norovirus Infections among Pediatric Patients in Qatar." Viruses 11, no. 5 (April 29, 2019): 400. http://dx.doi.org/10.3390/v11050400.

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Background: Norovirus (NoV) is recognized as the second most important etiological agent leading to acute gastroenteritis globally. In order to determine the burden and characteristics of NoV infections in children in Qatar, profiling of circulating genotypes and their correlation with demographics and clinical manifestations were evaluated. Methods: A total of 177 NoV-positive fecal samples were collected from children suffering from acute gastroenteritis (AGE) during two-year period between June 2016 and June 2018. The age of the subjects ranged between 3 months and 12 years (median of 15 months). Genotyping was performed by amplifying and sequencing parts of viral VP1 and RNA-dependent RNA polymerase (RdRp) regions. Phylogenetic analysis and evolutionary relationships were performed using MEGA7.0. Fisher’s exact test was used to run statistical analysis for the clinical and demographical characteristics of circulating strains. Results: Overall, NoV infections were relatively higher in males than females with a ratio of 1.3:1 (p = 0.0073). Most of the NoV infections were reported in children between 1 and 3 years old (49.7%), followed by those <1 and >3 years of age (41.2% and 9.1%, respectively). NoV infections occurred throughout the year, with a noticeable increase in summer (36.6%) and drop in winter (25.4%). Nearly all (98.8%) NoV-infected children were positive for genogroup II (GII) compared to only two samples (1.2%) being positive for genogroup I (GI): GI.3 and GI.4. NoV genotype GII.4 (62.2%), GII.2 (15.8%), and GII.3 (13.5%) were predominant in our study. The detected strains shared >98% sequence homology with emerging recombinant strain of GII.P16-GII.4/RUS/Novosibirsk/2017 (MG892929), GII.P16-GII.4 Sydney/2012 (KY887601), GII.4 Sydney/2012, recombinant GII.P4 New Orleans /2009/GII.4 Sydney 2012 (MG585810.1), and the emerging strain GII.P16-GII.2 CHN/2017 (MH321823). Severe clinical illness (vesikari score >10) was reported in children infected with genotypes sharing homology with the above emerging strains. While GII.4 was reported in all age groups, NoV GII.3 infections were higher in children <1 year of age. Both genogroups (GII.4 and GII.3) in addition to GII.2 reported higher incidence in Qatari subjects compared to other nationalities (p = 0.034). Conclusion: This is the first report about NoV molecular epidemiology in Qatar. The most detected NoV strain was genogroup GII, which is the dominant genotype in the Middle East region. Further, we report GII.4, GII.2, and GII.3 as the most predominant NoV genotypes in our study. Moreover, disease severity scores were higher among children genotyped with genogroup GI (GI.4) and genogroup GII (GII.4, GII.2, GII.3, GII.6, and GII.7).
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43

Flannery, John, Sinéad Keaveney, Paulina Rajko-Nenow, Vincent O'Flaherty, and William Doré. "Concentration of Norovirus during Wastewater Treatment and Its Impact on Oyster Contamination." Applied and Environmental Microbiology 78, no. 9 (February 24, 2012): 3400–3406. http://dx.doi.org/10.1128/aem.07569-11.

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ABSTRACTThe concentrations ofEscherichia coli, F-specific RNA bacteriophage (FRNA bacteriophage), and norovirus genogroup I (NoV GI) and norovirus genogroup II (NoV GII) in wastewater were monitored weekly over a 1-year period at a wastewater treatment plant (WWTP) providing secondary wastewater treatment. A total of 49 samples of influent wastewater and wastewater that had been treated by primary and secondary wastewater treatment processes (primary and secondary treated wastewater) were analyzed. Using a real-time reverse transcription-quantitative PCR (RT-qPCR), the mean NoV GI and NoV GII concentrations detected in effluent wastewater were 2.53 and 2.63 log10virus genome copies 100 ml−1, respectively. The mean NoV concentrations in wastewater during the winter period (January to March) (n= 12) were 0.82 (NoV GI) and 1.41 (NoV GII) log units greater than the mean concentrations for the rest of the year (n= 37). The mean reductions of NoV GI and GII during treatment were 0.80 and 0.92 log units, respectively, with no significant difference detected in the extent of NoV reductions due to season. No seasonal trend was detected in the concentrations ofE. colior FRNA bacteriophage in wastewater influent and showed mean reductions of 1.49 and 2.13 log units, respectively. Mean concentrations of 3.56 and 3.72 log10virus genome copies 100 ml−1for NoV GI and GII, respectively, were detected in oysters sampled adjacent to the WWTP discharge. A strong seasonal trend was observed, and the concentrations of NoV GI and GII detected in oysters were correlated with concentrations detected in the wastewater effluent. No seasonal difference was detected in concentrations ofE. colior FRNA bacteriophage detected in oysters.
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44

Krumova-Valcheva, G., Z. Mladenova, and Y. Gogov. "Study on norovirus contamination of live bivalve molluscs using real-time PCR." BULGARIAN JOURNAL OF VETERINARY MEDICINE 23, no. 4 (2020): 478–86. http://dx.doi.org/10.15547/bjvm.2019-0008.

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Foodborne and waterborne viruses are a major cause of human morbidity. Of them, noroviruses are recognised as the leading causative agents of sporadic infections and epidemic outbreaks of acute gastroenteritis in humans. Contaminated food products and water are the main source of infection with noroviruses. The infection of bivalve molluscs with human pathogenic viruses occurs by faecal contamination in the production coastal waters. In this study, 47 samples of live bivalve molluscs, including 15 samples of cultivated mussels (Mytilus galloprovincialis) and 32 samples of wild mussels (Tapes decussatus), collected from the Bulgarian and Mediterranean coasts, respectively, were submitted to RT-real-time TaqMan PCR to detect the presence of noroviruses genotype GI and GII. Norovirus genotype GII was found in 11 (23.4%) of all the samples tested. A single mollusc sample (2.1%) was positive for both norovirus genotypes. Our results demonstrated that shellfish intended for sale on the Bulgarian market might pose a potential risk for acquiring norovirus infection. Thus, food safety quality control of shellfish by optimised and standardised methods for detection of foodborne viruses, including noroviruses, should be urgently implemented in Bulgaria.
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45

Hansman, Grant S., Katsuro Natori, Haruko Shirato-Horikoshi, Satoko Ogawa, Tomoichiro Oka, Kazuhiko Katayama, Tomoyuki Tanaka, et al. "Genetic and antigenic diversity among noroviruses." Journal of General Virology 87, no. 4 (April 1, 2006): 909–19. http://dx.doi.org/10.1099/vir.0.81532-0.

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Human norovirus (NoV) strains cause a considerable number of outbreaks of gastroenteritis worldwide. Based on their capsid gene (VP1) sequence, human NoV strains can be grouped into two genogroups (GI and GII) and at least 14 GI and 17 GII genotypes (GI/1–14 and GII/1–17). Human NoV strains cannot be propagated in cell-culture systems, but expression of recombinant VP1 in insect cells results in the formation of virus-like particles (VLPs). In order to understand NoV antigenic relationships better, cross-reactivity among 26 different NoV VLPs was analysed. Phylogenetic analyses grouped these NoV strains into six GI and 12 GII genotypes. An antibody ELISA using polyclonal antisera raised against these VLPs was used to determine cross-reactivity. Antisera reacted strongly with homologous VLPs; however, a number of novel cross-reactivities among different genotypes was observed. For example, GI/11 antiserum showed a broad-range cross-reactivity, detecting two GI and 10 GII genotypes. Likewise, GII/1, GII/10 and GII/12 antisera showed a broad-range cross-reactivity, detecting several other distinct GII genotypes. Alignment of VP1 amino acid sequences suggested that these broad-range cross-reactivities were due to conserved amino acid residues located within the shell and/or P1-1 domains. However, unusual cross-reactivities among different GII/3 antisera were found, with the results indicating that both conserved amino acid residues and VP1 secondary structures influence antigenicity.
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46

Mulondo, G., R. Khumela, J. P. Kabue, A. N. Traore, and N. Potgieter. "Molecular Characterization of Norovirus Strains Isolated from Older Children and Adults in Impoverished Communities of Vhembe District, South Africa." Advances in Virology 2020 (June 29, 2020): 1–9. http://dx.doi.org/10.1155/2020/8436951.

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Background. Human norovirus (NoV) is an etiological agent associated with acute gastroenteritis (AGE) in both children and adults worldwide. However, very few studies have been reported on the prevalence and genetic diversity of NoV strains in children older than 5 years of age and adults with little or inadequate water and sanitation conditions. Objectives. The aim of this study was assessing the prevalence of the human norovirus in older children and adults suffering with diarrhoea from rural communities in the Vhembe district, Limpopo province. Methods. Between August 2017 and October 2018, stool samples were collected from outpatients suffering from AGE and screened for NoV strains using the RIDA©GENE norovirus I and II real-time one-step RT-PCR. RNA extracts of NoV-positive samples were subjected to RT-PCR amplification and nucleotide sequencing to genotype the positive NoV strains. Results. Out of 80 collected stool samples, 13 (16%) were tested positive for norovirus. Genogroup GII was identified in 6/13 (46%) samples and genogroup GI in 7/13 (54%) samples. The sequence analyses showed multiple genotypes including GII.Pg, GII.1, GII.2, GII.4, and GI.3. Phylogenetic analysis revealed the relatedness of NoV genotypes identified with other strains reported globally. Conclusion. Continued systematic surveillance to evaluate norovirus association with diarrhoea is needed to assist with epidemiological surveillance and disease burden in people of all the age groups.
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47

Rupnik, Agnieszka, William Doré, Leon Devilly, James Fahy, Amy Fitzpatrick, Wiebke Schmidt, Kevin Hunt, Francis Butler, and Sinéad Keaveney. "Evaluation of Norovirus Reduction in Environmentally Contaminated Pacific Oysters During Laboratory Controlled and Commercial Depuration." Food and Environmental Virology 13, no. 2 (March 2, 2021): 229–40. http://dx.doi.org/10.1007/s12560-021-09464-2.

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AbstractNorovirus contamination of oysters is the lead cause of non-bacterial gastroenteritis and a significant food safety concern for the oyster industry. Here, norovirus reduction from Pacific oysters (Crassostrea gigas), contaminated in the marine environment, was studied in laboratory depuration trials and in two commercial settings. Norovirus concentrations were measured in oyster digestive tissue before, during and post-depuration using the ISO 15216-1 quantitative real-time RT-PCR method. Results of the laboratory-based studies demonstrate that statistically significant reductions of up to 74% of the initial norovirus GII concentration was achieved after 3 days at 17–21 °C and after 4 days at 11–15 °C, compared to 44% reduction at 7–9 °C. In many trials norovirus GII concentrations were reduced to levels below 100 genome copies per gram (gcg−1; limit of quantitation; LOQ). Virus reduction was also assessed in commercial depuration systems, routinely used by two Irish oyster producers. Up to 68% reduction was recorded for norovirus GI and up to 90% for norovirus GII reducing the geometric mean virus concentration close to or below the LOQ. In both commercial settings there was a significant difference between the levels of reduction of norovirus GI compared to GII (p < 0.05). Additionally, the ability to reduce the norovirus concentration in oysters to < LOQ differed when contaminated with concentrations below and above 1000 gcg−1. These results indicate that depuration, carried out at elevated (> 11 °C) water temperatures for at least 3 days, can reduce the concentration of norovirus in oysters and therefore consumer exposure providing a practical risk management tool for the shellfish industry.
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48

Rajko-Nenow, Paulina, Allison Waters, Sinéad Keaveney, John Flannery, Gráinne Tuite, Suzie Coughlan, Vincent O'Flaherty, and William Doré. "Norovirus Genotypes Present in Oysters and in Effluent from a Wastewater Treatment Plant during the Seasonal Peak of Infections in Ireland in 2010." Applied and Environmental Microbiology 79, no. 8 (February 8, 2013): 2578–87. http://dx.doi.org/10.1128/aem.03557-12.

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ABSTRACTWe determined norovirus (NoV) concentrations in effluent from a wastewater treatment plant and in oysters during the peak period of laboratory-confirmed cases of NoV infection in Ireland in 2010 (January to March). Weekly samples of influent, secondary treated effluent, and oysters were analyzed using real-time quantitative reverse transcription-PCR for NoV genogroup I (GI) and genogroup II (GII). The mean concentration of NoV GII (5.87 × 104genome copies 100 ml−1) in influent wastewater was significantly higher than the mean concentration of NoV GI (1.40 × 104genome copies 100 ml−1). The highest concentration of NoV GII (2.20 × 105genome copies 100 ml−1) was detected in influent wastewater during week 6. Over the study period, a total of 931 laboratory-confirmed cases of NoV GII infection were recorded, with the peak (n= 171) occurring in week 7. In comparison, 16 cases of NoV GI-associated illness were reported during the study period. In addition, the NoV capsid N/S domain was molecularly characterized for selected samples. Multiple genotypes of NoV GI (GI.1, GI.4, GI.5, GI.6, and GI.7) and GII (GII.3, GII.4, GII.6, GII.7, GII.12, GII.13, and GII.17), as well as 4 putative recombinant strains, were detected in the environmental samples. The NoV GII.4 variant 2010 was detected in wastewater and oyster samples and was the dominant strain detected in NoV outbreaks at that time. This study demonstrates the diversity of NoV genotypes present in wastewater during a period of high rates of NoV infection in the community and highlights the potential for the environmental spread of multiple NoV genotypes.
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PEPE, TIZIANA, IOLE VENTRONE, ELISABETTA SUFFREDINI, MARINA CERUSO, LUCIANA CROCI, ANIELLO ANASTASIO, and MARIA LUISA CORTESI. "Norovirus Monitoring in Bivalve Molluscs Harvested and Commercialized in Southern Italy." Journal of Food Protection 75, no. 5 (May 1, 2012): 976–81. http://dx.doi.org/10.4315/0362-028x.jfp-11-424.

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Norovirus (NoV) is the main cause of human nonbacterial gastroenteritis throughout the world. NoVs are classified into five genogroups: GI, GII, GIII, GIV, and GV. NoVs from GI and GII are the most commonly reported NoVs associated with human infections, and raw or undercooked shellfish have been identified as the main potential infection vehicle. European Commission Regulation 2073/2005 defines only bacteriological parameters for use as safety criteria for shellfish because reference methods for detection of viruses are lacking. From July 2007 to April 2010, 163 shellfish samples were collected in southern Italy from harvesting areas, authorized or nonauthorized retailers, and a restaurant after an outbreak of human gastroenteritis. The shellfish were analyzed for the presence of NoVs from GI and GII using the one-step real-time reverse transcription PCR protocol. A total of 94 shellfish samples (57.7%) were positive for the presence of NoV, and GII was the most frequently identified genogroup.
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50

Kong, Byoung-Hwa, Sung-Geun Lee, Sang-Ha Han, Ji-Young Jin, Weon-Hwa Jheong, and Soon-Young Paik. "Development of Enhanced Primer Sets for Detection of Norovirus." BioMed Research International 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/103052.

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Norovirus (NV) is a major viral pathogen that causes nonbacterial acute gastroenteritis and outbreaks of food-borne disease. The genotype of NV most frequently responsible for NV outbreaks is GII.4, which accounts for 60–80% of cases. Moreover, original and new NV variant types have been continuously emerging, and their emergence is related to the recent global increase in NV infection. In this study, we developed advanced primer sets (NKI-F/R/F2, NKII-F/R/R2) for the detection of NV, including the variant types. The new primer sets were compared with conventional primer sets (GI-F1/R1/F2, SRI-1/2/3, GII-F1/R1/F2, and SRII-1/2/3) to evaluate their efficiency when using clinical and environmental samples. Using reverse transcription polymerase chain reaction (RT-PCR) and seminested PCR, NV GI and GII were detected in 91.7% (NKI-F/R/F2), 89.3% (NKII-F/R/R2), 54.2% (GI-F1/R1/F2), 52.5% (GII-F1/R1/F2), 25.0% (SRI-1/2/3), and 32.2% (SRII-1/2/3) of clinical and environmental specimens. Therefore, our primer sets perform better than conventional primer sets in the detection of emerged types of NV and could be used in the future for epidemiological diagnosis of infection with the virus.
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