Higher Viral Load of Emerging Norovirus GII.P16-GII.2 than Pandemic GII.4 and Epidemic GII.17, Hong Kong, China.
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PROVIDER: S-EPMC6302574 | BioStudies |
REPOSITORIES: biostudies
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Project description:BACKGROUND:In late 2016, an uncommon recombinant NoV genotype called GII.P16-GII.2 caused a sharp increase in outbreaks of acute gastroenteritis in different countries of Asia and Europe, including China. However, we did not observe a drastic increase in sporadic norovirus cases in the winter of 2016 in Huzhou. Therefore, we investigate the prevalence and genetic diversity of NoVs in the sporadic acute gastroenteritis (AGE) cases from January 2016 to December 2017 in Huzhou City, Zhejiang, China. METHODS:From January 2016 to December 2017, a total of 1001 specimens collected from patients with AGE were screened for NoV by real-time RT-PCR. Partial sequences of the RNA-dependent RNA polymerase (RdRp) and capsid gene of the positive samples were amplified by RT-PCR and sequenced. Genotypes of NoV were confirmed by online NoV typing tool and phylogenetic analysis. Complete VP1 sequences of GII.P16-GII.2 strains detected in this study were further obtained and subjected into sequence analysis. RESULTS:In total, 204 (20.4%) specimens were identified as NoV-positive. GII genogroup accounted for most of the NoV-infected cases (98.0%, 200/204). NoV infection was found in all age groups tested (<?5, 5-15, 16-20, 21-30, 31-40, 41-50, 51-60, and >60 years), with the 5-15 year age group having the highest detection rate (17/49, 34.7%). Higher activity of NoV infection could be seen in winter-spring season. The predominant NoV genotypes have changed from GII.Pe-GII.4 Sydney2012 and GII.P17-GII.17 in 2016 to GII.P16-GII.2, GII.Pe-GII.4 Sydney2012 and GII.P17-GII.17 in 2017. Phylogenetic analyses revealed that 2016-2017 GII.P16-GII.2 strains were most closely related to Japan 2010-2012 cluster in VP1 region and no common mutations were found in the amino acids of the HBGA-binding sites and the predicted epitopes. CONCLUSIONS:We report the emergence of GII.P16-GII.2 strains and characterize the molecular epidemiological patterns NoV infection between January 2016 and December 2017 in Huzhou. The predominant genotypes of NoV during our study period are diverse. VP1 amino acid sequences of 2016-2017 GII.P16-GII.2 strains remain static after one year of circulation.
| S-EPMC6056945 | BioStudies
Project description:Noroviruses are the leading cause of acute gastroenteritis (AGE) in all age groups worldwide. Despite the high genetic diversity of noroviruses, most AGE outbreaks are caused by a single norovirus genotype: GII.4. Since 1995, several different variants of norovirus GII.4 have been associated with pandemics, with each variant circulating for 3 to 8 years. The Sydney_2012 variant was first reported in Australia and then in other countries. A new variant, GII.P16-GII.4, was recently described in Japan and South Korea and then in the USA, France, Germany and England. In our study, 190 faecal specimens were collected from children admitted to a paediatric hospital and a public health facility during a surveillance study of sporadic cases of AGE conducted between January 2015 and July 2016. The norovirus was detected by RT-qPCR in 51 samples (26.8%), and in 37 of them (72.5%), the ORF1-2 junction was successfully sequenced. The new recombinant GII.P16-GII.4 Sydney was revealed for the first time in Brazil in 2016 and predominated among other strains (9 GII.Pe-GII.4, 3 GII.P17-GII.17, 1 GII.Pg-GII.1, 1 GII.P16-GII.3 and 1 GII.PNA-GII.4). The epidemiological significance of this new recombinant is still unknown, but continuous surveillance studies may evaluate its impact on the population, its potential to replace the first recombinant GII.Pe-GII.4 Sydney 2012 variant, and the emergence of new recombinant forms of GII.P16.
| S-EPMC5728567 | BioStudies
Project description:BACKGROUND:Based on the impact public health of norovirus and the current progress in norovirus vaccine development, it is necessary to continuously monitor the epidemiology of norovirus infection, especially in children who are more susceptible to norovirus. OBJECTIVES:To monitor the activity and genotypes of norovirus infection in sporadic diarrhea in Shanghainese children during 2014-2018. STUDY DESIGN:Acute diarrheal cases were prospectively enrolled in the outpatient setting. Real-time reverse transcription-polymerase chain reaction was used for screening norovirus GI and GII genogroups. Dual norovirus genotypes were identified based on the partial capsid and polymerase gene sequences. RESULTS:Of the 3422 children with diarrhea, 510 (14.9%) were positive for noroviruses with 13 (2.5%) strains being GI genogroup and 497 (97.5%) strains being GII genogroup. Five distinct capsid GII genotypes were identified, including GII.4-Sydney/2012 (71.8%), GII.3 (13.8%), GII.17 (7.8%), GII.2 (6.0%), GII.6 (0.3%) and GII.8 (0.3%). Seven polymerase GII genotypes were identified, including GII.Pe (77.0%), GII.P12 (11.0%), GII.P17 (9.0%), GII.P16 (2.1%), and GII.P7, GII.P8 and GII.P2 in each (0.3%). Eleven distinct polymerase/capsid genotypes were identified with GII.Pe/GII.4-Sydney/2012 (74.2%), GII.P12/GII.3 (11.7%) and GII.P17/GII.17 (7.7%) being common. GII.P17/GII.17 strains were detected since September 2014. Recombinant GII.P16/GII.2 strains were detected since December 2016. CONCLUSIONS:Norovirus is a major pathogen causing diarrhea in Shanghainese children. GII.Pe/GII.4-Sydney/2012 strains remained the predominant genotype. The emergence of GII.P17/GII.17 and GII.P16/GII.2 strains in sporadic diarrhea was consistent with norovirus-associated outbreaks attributable to these 2 novel variants in China. Continuous monitoring norovirus genotypes circulating in pediatric population is needed for current vaccine development.
| S-EPMC7198057 | BioStudies
Project description:Noroviruses (NoVs) are enteric viruses that cause acute gastroenteritis, and the pandemic GII.4 genotype is spreading and evolving rapidly. The recombinant GII.P16/GII.4_Sydney strain emerged in 2016, replacing GII.P31/GII.4_Sydney (GII.P31 formerly known as GII.Pe) in some countries. We analyzed the complete genome of 20 NoV strains (17 GII.P31/GII.4_ Sydney and 3 GII.P16/GII.4_Sydney) from Belém and Manaus, Brazil, collected from 2012 to 2016. Phylogenetic trees were constructed by maximum likelihood method from 191 full NoV-VP1 sequences, demonstrated segregation of the Sydney lineage in two larger clades, suggesting that GII.4 strains associated with GII.P16 already have modifications compared with GII.P31/GII.4. Additionally, the Bayesian Markov Chain Monte Carlo method was used to reconstruct a time-scaled phylogenetic tree formed by GII.P16 ORF1 sequences (n = 117) and three complete GII.P16 sequences from Belém. The phylogenetic tree indicated the presence of six clades classified into different capsid genotypes and locations. Evolutionary rates of the ORF1 gene of GII.P16 strains was estimated at 2.01 × 10-3 substitutions/site/year, and the most recent common ancestors were estimated in 2011 (2011-2012, 95% HPD). Comparing the amino acid (AA) sequence coding for ORF1 with the prototype strain GII.P16/GII.4, 36 AA changes were observed, mainly in the non-structural proteins p48, p22, and RdRp. GII.P16/GII.4 strains of this study presented changes in amino acids 310, 333, 373, and 393 of the antigenic sites in the P2 subdomain, and ML tree indicating the division within the Sydney lineage according to the GII.P16 and GII.P31 polymerases. Notably, as noroviruses have high recombination rates and the GII.4 genotype was prevalent for a long time in several locations, additional and continuous evolutionary analyses of this new genotype should be needed in the future.
| S-EPMC7423841 | BioStudies
Project description:A total of 1 590 fecal swabs and stool samples from sporadic acute gastroenteritis patients of all ages were collected from January 2013 to March 2018 in the Zhoushan Islands, China, with 99 (6.23%) samples subsequently identified as human norovirus (HuNoV) positive. Phylogenetic analysis of partial RdRp and VP1 gene regions identified 10 genotypes of the GII genogroup and 3 genotypes of the GI genogroup. The predominant genotype was GII.P17-GII.17 (42.86%, 33/77), followed by GII.Pe-GII.4_Sydney 2012 (24.68%, 19/77) and GII.P16-GII.2 (12.96%, 10/77). However, the prevailing genotype in the Zhoushan Islands has shifted on three separate occasions. The GII.Pe-GII.4_Sydney_2012 strain was dominant in 2013-2014, the GII.P17-17 strain was dominant in 2015-2016, and the GII.P16-GII.2 strain was dominant in 2017. Divergence analysis showed that the re-emerging GII.P16-GII.2 strains clustered with the Japanese 2010-2012 GII.P16-GII.2 strains, and the time of the most recent common ancestor was estimated to have occurred in 2012 to 2013. The evolutionary rates of the RdRp gene region of the GII.P16 genotype and the VP1 gene region of the GII.2 genotype were 2.64 × 10(-3) (95% HPD interval, 2.17-3.08 × 10(-3)) and 3.36 × 10(-3) (95% HPD interval, 2.66-4.04 × 10(-3)) substitutions/site/year, respectively. The migration pattern of the HuNoV GII.2 genotype in China demonstrated that the re-emerging GII.P16-GII.2 strains were first introduced into Hong Kong from Japan, and then spread from Hong Kong to other coastal areas. Our results also showed that the GII.P16-GII.2 strains in the Zhoushan Islands were likely introduced from Jiangsu Province, China, in 2016.
| S-EPMC6051660 | BioStudies
Project description:Background:With the help of an existing citywide comprehensive surveillance on gastroenteritis outpatients, although norovirus genogroup II (NoV GII) was tested routinely, its genotypes were never investigated systematically on a municipal level. This study aimed to understand the prevalence, major genotypes and evolutional trends of NoV GII in Shanghai during the period of 2016-2018, and to provide molecular bases for early warning for any potential NoV outbreaks. Methods:27 sentinel hospitals from all 16 districts were recruited by stratified probability proportional to size (PPS) method in Shanghai comprehensive diarrhea surveillance programme. Stool samples were collected and screened for NoV GII by real-time reverse transcription polymerase chain reaction (qRT-PCR). For samples that were positive in qRT-PCR, conventional RT-PCR was performed to amplify the ORF1-ORF2 junction of NoV GII gene. Generated sequences were typed by RIVM online genotyping tool, and then strains of interest were analyzed phylogenetically using MEGA 6.0. Results:A total of 7883 stool samples were collected from diarrhea outpatients, among which 6474 were from adults and 1409 were from children. 13.66% (1077 cases) were screened positive in qRT-PCR for NoV GII, from which 71.96% (775 cases) were sequenced successfully. The top three genotypes were GII.Pe/GII.4 (37%), GII.P17/GII.17 (26%) and GII.P16/GII.2 (17%). While GII.Pe/GII.4 detection rate decreased significantly over the 3 years (from 48.4 to 20.9%); GII.P16/GII.2 appeared for the first time in October 2016 and rose rapidly to 27.0% in 2017, but fell back to 23.4% in 2018. Meanwhile there was a significant increase for both GII.P12/GII.3 and GII.P7/GII.6 recombinant genotypes detected in adult population in 2018. Phylogenic analysis revealed the existence of multiple gene clusters within both of these recombinant genotypes. Conclusion:Unlike the alternating circulation of GII.4 and non-GII.4 NoV observed in 2016 or 2017, the genotype profile of NoV GII in 2018 was characterized by the co-prevalence of multiple recombinant genotypes. A recent increase in detection rate in less reported recombinant genotypes such as GII.P12/GII.3 and GII.P7/GII.6 among adult population calls for a continuing close monitoring on NoV GII genotypes in case of potential local outbreaks.
| S-EPMC6660925 | BioStudies
Project description:An early increase in outbreaks of norovirus gastroenteritis characterised at the French National Reference Centre occurred this winter season. They were concurrent with an unusual pattern of circulating strains, with three predominant genotypes: the re-emergent variant GII.P4 2009-GII.4 2012 found in 28% of norovirus outbreaks and two new emergent recombinant strains GII.P16-GII.4 2012 and GII.P16-GII.2 never before observed in France, found in 24% and 14% of norovirus outbreaks, respectively.
| S-EPMC5476982 | BioStudies
Project description:A new recombinant norovirus GII.P16-GII.2 outnumbered pandemic GII.4 as the predominant GII genotype in the winter of 2016-2017 in Hong Kong, China. Half of hospitalized case-patients were older children and adults, including 13 young adults. This emergent norovirus targets a wider age population compared with circulating pandemic GII.4 strains.
| S-EPMC5652449 | BioStudies
Project description:Background:Human noroviruses are the leading cause of acute gastroenteritis. Strains of the GII.4 genotype cause pandemic waves associated with viral evolution and subsequent antigenic drift and ligand-binding modulation. In November 2015, a novel GII.4 Sydney recombinant variant (GII.P16-GII.4 Sydney) emerged and replaced GII.Pe-GII.4 Sydney as the predominant cause of acute gastroenteritis in the 2016-2017 season in the United States. Methods:Virus-like particles of GII.4 2012 and GII.4 2015 were compared for ligand binding and antibody reactivity, using a surrogate neutralization assay. Results:Residue changes in the capsid between GII.4 2012 and GII.4 2015 decreased the potency of human polyclonal sera and monoclonal antibodies. A change in epitope A resulted in the complete loss of reactivity of a class of blockade antibodies and reduced levels of a second antibody class. Epitope D changes modulated monoclonal antibody potency and ligand-binding patterns. Conclusions:Substitutions in blockade antibody epitopes between GII.4 2012 and GII.4 2015 influenced antigenicity and ligand-binding properties. Although the impact of polymerases on fitness remains uncertain, antigenic variation resulting in decreased potency of antibodies to epitope A, coupled with altered ligand binding, likely contributed significantly to the spread of GII.4 2015 and its replacement of GII.4 2012 as the predominant norovirus outbreak strain.
| S-EPMC5939617 | BioStudies
Project description:Noroviruses evolve by antigenic drift and recombination, which occurs most frequently at the junction between the non-structural and structural protein coding genomic regions. In 2015, a novel GII.P16-GII.4 Sydney recombinant strain emerged, replacing the predominance of GII.Pe-GII.4 Sydney among US outbreaks. Distinct from GII.P16 polymerases detected since 2010, this novel GII.P16 was subsequently detected among GII.1, GII.2, GII.3, GII.10 and GII.12 viruses, prompting an investigation on the unique characteristics of these viruses. Norovirus positive samples (n = 1807) were dual-typed, of which a subset (n = 124) was sequenced to yield near-complete genomes. CaliciNet and National Outbreak Reporting System (NORS) records were matched to link outbreak characteristics and case outcomes to molecular data and GenBank was mined for contextualization. Recombination with the novel GII.P16 polymerase extended GII.4 Sydney predominance and increased the number of GII.2 outbreaks in the US. Introduction of the novel GII.P16 noroviruses occurred without unique amino acid changes in VP1, more severe case outcomes, or differences in affected population. However, unique changes were found among NS1/2, NS4 and VP2 proteins, which have immune antagonistic functions, and the RdRp. Multiple polymerase-capsid combinations were detected among GII viruses including 11 involving GII.P16. Molecular surveillance of protein sequences from norovirus genomes can inform the functional importance of amino acid changes in emerging recombinant viruses and aid in vaccine and antiviral formulation.
| S-EPMC6631344 | BioStudies