OBJECTIVETo reveal the genetic characteristics of GII.12 Norovirus strains isolating from stool samples of adults with diarrhea in Beijing during 2008-2009.

METHODSRdRp, ORF2, ORF3 and ORF1/ORF2 overlap region were respectively amplified by primers using RT-PCR. The products were purified, cloned, sequenced and then aligned, phylogenetic and recombinant analyzed by softwares of DNAStar, MEGA and SimPlot.

RESULTSAccording to the phylogenetic analysis, 11 strains belonged to G II.g in the RdRp region,while GII.12 in the ORF2 and ORF3. SimPlot analysis further confirmed the 11 strains were recombinant strains ( G II.g [RdRp]/G II.12 [capsid]).

CONCLUSIONG II.12 Norovirus prevailing in Beijing and other regions of the world belonged to the same strain, and we identified the genetic characteristics of G II.12 Norovirus in Beijing.

China ; Norovirus ; classification ; genetics ; Phylogeny ; Recombination, Genetic ; Time Factors

Norovirus ; chemistry ; genetics ; physiology ; ultrastructure ; Open Reading Frames ; Virus Replication

OBJECTIVETo obtain information on viral molecular structural and evolutionary characteristics, we conducted the SZ2010422 full-length genomic analysis.

METHODSPrimers were designed by New Orleans full sequence, SZ2010422 full genome was amplified by RT-PCR, the whole genome sequence and the capsid domain amino acid sites was analysised after cloned and sequenced.

RESULTSThe genome of G II-4 Norovirus SZ2010422 strain was consist of 7559 bp, it revealed three ORFs composites of the whole genome, ORF1 (5100 bp), ORF2 (1623 bp), ORF3 (807 bp) respectively, ORF1 and ORF2 had 19 nucleotide overlap. By evolutionary comparative analysis found SZ2010422 genomic nucleotide sequences with reference strains of G II-4 New Orleans1805 strains the highest homology with a total length of homology was 99.3%, of ORF1 (99.5%), ORF2 (99.2%), ORF3 (98.6%). Phylogenetic analyses showed SZ2010422 belonging to G II-4 New Orleans variant. Date of 541 amino acid analyses showed: New Orleans variant strains of popular sites: aa310N or K, --> S aa341D --> of N, aa359T--> S, aa396H --> P, aa460H --> Y.

CONCLUSIONNorovirus SZ2010422 belonged to the G II-4 New Orleans variant. In This study, SZ2010422 full sequence can be used not only as a full-length NoV variant sequence standard for future comparison studies, but also as useful material for the public health field by enabling the diagnosis, vaccine development, and prediction of new emerging variants. Noroviruses; Genes; Sequence analysis

China ; Genome, Viral ; Norovirus ; classification ; genetics ; Open Reading Frames ; Phylogeny ; Sequence Analysis, DNA

Caliciviridae Infections ; epidemiology ; virology ; Gastroenteritis ; virology ; Genetic Variation ; Genotype ; Humans ; Norovirus ; classification ; genetics

OBJECTIVETo explore a convenient and effective method for norovirus nucleic acid extraction from oysters suitable for long-term viral surveillance.

METHODSTwo methods, namely method A (glycine washing and polyethylene glycol precipitation of the virus followed by silica gel centrifugal column) and method B (protease K digestion followed by application of paramagnetic silicon) were compared for their performance in norovirus nucleic acid extraction from oysters. Real-time RT-PCR was used to detect norovirus in naturally infected oysters and in oysters with induced infection.

RESULTSThe two methods yielded comparable positive detection rates for the samples, but the recovery rate of the virus was higher with method B than with method A.

CONCLUSIONMethod B is a more convenient and rapid method for norovirus nucleic acid extraction from oysters and suitable for long-term surveillance of norovirus.

Animals ; Centrifugation ; methods ; Norovirus ; genetics ; isolation & purification ; Ostreidae ; virology ; RNA, Viral ; isolation & purification

OBJECTIVES: To study the molecular epidemiological characteristics of norovirus in children with acute gastroenteritis from 2017 to 2019. METHODS: A retrospective analysis was performed on the medical data of children with acute gastroenteritis who were admitted to Children's Hospital of Chongqing Medical University from January 2017 to December 2019. A total of 1 458 stool samples were collected from the children, and viral RNA was extracted. Reverse transcription polymerase chain reaction was used for gene amplification, sequencing, and genotype identification of the VP1 region of capsid protein in norovirus. RESULTS: Among the 1 458 stool samples, 158 (10.8%) were positive for norovirus. There was no significant difference in the positive detection rate of norovirus between different years ( CONCLUSIONS Norovirus GII.4 Sydney 2012 was the major epidemic strain in the children with norovirus gastroenteritis from 2017 to 2019. Although norovirus infection can exist throughout the year, August to October is the peak period. During this period, norovirus surveillance and key population protection are strengthened to help prevent and control norovirus diarrhea.
Child ; Feces ; Female ; Gastroenteritis/epidemiology* ; Humans ; Male ; Norovirus/genetics* ; Phylogeny ; Retrospective Studies

Objective: To explore the characteristics of viral infections in children with diarrhea in Beijing from 2018 to 2022. Methods: Real-time PCR and enzyme-linked immunosorbent assay were used to detect viral nucleic acid of Norovirus (NoV), Sappovirus (SaV), Astrovirus (AstV), Enteric Adenovirus (AdV) or antigen of Rotavirus (RV) in 748 stool samples collected from Beijing Capital Institute of Pediatrics from January 2018 to December 2021. Subsequently, the reverse transcription PCR or PCR method was used to amplify the target gene of the positive samples after the initial screening, followed by sequencing, genotyping and evolution analysis, so as to obtain the characteristics of these viruses. Phylogenetic analysis was performed using Mega 6.0. Results: From 2018 to 2021, the overall detection rate of the above five common viruses was 37.6%(281/748)in children under 5 years old in Beijing. NoV, Enteric AdV and RV were still the top three diarrhea-related viruses, followed by AstV and SaV, accounting for 41.6%, 29.2%, 27.8%, 8.9% and 7.5%, respectively. The detection rate of co-infections with two or three diarrhea-related viruses was 4.7% (35/748). From the perspective of annual distribution, the detection rate of Enteric AdV was the highest in 2021, while NoV was predominant in the other 4 years. From the perspective of genetic characteristics, NoV was predominant by GⅡ.4, and after the first detection of GⅡ.4[P16] in 2020, it occupied the first two gene groups together with GⅡ.4[P31]. Although the predominant RV was G9P[8], the rare epidemic strain G8P[8] was first detected in 2021. The predominant genotypes of Enteric AdV and AstV were Ad41 and HAstV-1. SaV was sporadic spread with a low detection rate. Conclusion: Among the diarrhea-related viruses infected children under 5 years of age in Beijing, the predominant strains of NoV and RV have changed and new sub-genotypes have been detected for the first time, while the predominant strains of AstV and Enteric AdV are relatively stable.
Child, Preschool ; Humans ; Infant ; Beijing/epidemiology* ; Diarrhea/epidemiology* ; Feces ; Norovirus/genetics* ; Phylogeny ; Rotavirus/genetics* ; Virus Diseases/epidemiology* ; Viruses/genetics*

Caliciviridae Infections ; epidemiology ; genetics ; virology ; China ; epidemiology ; Gastroenteritis ; virology ; Humans ; Molecular Epidemiology ; Norovirus ; genetics ; RNA, Viral ; isolation & purification

Noroviruses (NoVs) are one of the most important foodborne viral pathogens worldwide. Shellfish are the most common carriers of NoVs as they can concentrate and accumulate large amounts of the virus through filter feeding from seawater. Shellfish may selectively accumulate NoVs with different genotypes, and this bioaccumulation may depend on the season and location. Our previous studies found various histo-blood group antigens (HBGAs) in shellfish tissues. While HBGAs might be the main reason that NoVs are accumulated in shellfish, the detailed mechanism behind NoV concentration and bioaccumulation in shellfish is not clear. Here we review current research into NoV bioaccumulation, tissue distribution, seasonal variation, and binding mechanism in shellfish. This paper may provide insight into controlling NoV transmission and decreasing the risks associated with shellfish consumption.
Animals ; Caliciviridae Infections ; transmission ; virology ; Food Contamination ; analysis ; Foodborne Diseases ; virology ; Humans ; Norovirus ; classification ; genetics ; isolation & purification ; physiology ; Shellfish ; virology

A new viral sampling concentration device was designed which was equipped with a new cationic filter membrane-Nanoceram suitable for field sampling. Norovirus Genegroup II was detected from environmental water with the aid of this device. The effects on virus recovery of prefiltration, various second-concentration methods, and different eluants were investigated through pre-experiment. The concentration optimized process, and the optimal concentration process were then determined. The results showed that the prefiltration had a profound effect on virus recovery, and two second-concentration method: PEG-NaC1 precipitation and celite adsorption, had almost the same concentration effects. The Na2 HPO4 solution of 0.15 mol/L was selected as the final eluant to elute the adsorbed Nuorovirus from the celite. The virus recovery of Nanoceram was determined to be 3.02%. Finally, successful detection of Norovirus GII in sewage from Yangqiao River, Fengtai District, Beijing was acheived. All these data had shown that the Naneceram filter concentration method could concentrate Norovirus from environmental water with a steady effects.
Filtration ; instrumentation ; methods ; Fractional Precipitation ; instrumentation ; methods ; Genotype ; Norovirus ; classification ; genetics ; isolation & purification ; Rivers ; virology ; Water Microbiology