Norovirus disease today

Cui

Cell Mol Biol (Noisy-le-grand)

et al. 2018

To investigate the codon usage patterns of all available VP1 gene sequences of the GII.2 genotype, to determine the factors that affect these patterns, and to provide comprehensive details of the characteristics and evolution of the gene. Complete 519 sequences of VP1 gene of the HuNoV GII.2 genotype with known sampling dates and geographic locations from 1971 -2017 were retrieved from the GenBank nucleotide database of the National Center for Biotechnology Information (NCBI) and analyzed. The percentage composition of T, C, A, and G nucleotides were 24.80 ± 0.30, 26.61 ± 0.31, 25.84 ± 0.13, and 22.75 ± 0.17 %, respectively, with C and A relatively more abundant than T and G, and C the most abundant (p < 0.0001). The values of T3s (34.10 ± 0.90 %) and C3s (33.54 ± 0.90 %) were significantly higher than those of A3s (29.98 ± 0.43 %) and G3s (24.13 ± 0.51 %) (p < 0.0001). While T3s was highest among the four nucleotides, G3s was the lowest. Among the 18 most frequently employed synonymous codons, six optional codons ended with T, five ended with C, five ended with A and two ended with G. Codons ending with T were the most frequently used. The ENC ranged from 51.90 to 54.25 (mean = 52.38 ± 0.43) among the 519 VP1 gene sequences. There were significant correlations between ENC and C % and G % (p < 0.01). Codons containing CpG (1 and 2 or 2 and 3 codon positions) showed the lowest frequencies, while 30, 29, and 2 codons were above, below and on the mean line, respectively. The first four principal components accounted for 69.11 % of the total variation, with the first, second, third, and fourth principal axes contributing 37.90, 14.83, 9.61, and 6.77 %, respectively. The strains were not clustered by country of isolation or year of sampling. Gravy were significantly correlated with T3s, C3s, G3s, GC3s, and ENC (p < 0.01). Mutation pressure and natural selection contributed to the codon usage bias of the VP1 gene of the HuNoV GII.2 genotype. There was a correlation between GC12s and GC3s (R 2 = 0.032; p < 0.0001). The relative neutrality was 3.20 %, while natural selection was 96.80 %. The VP1 gene exhibits low codon usage bias which is affected primarily by natural selection, followed by mutation pressure and translational selection.

Section: Discussionmentioning

confidence: 99%

Analysis of codon usage bias in the VP1 gene of the human norovirus GII.2 genotype

Cui

Cell Mol Biol (Noisy-le-grand)

et al. 2018

Journal of Medical Virology

“…NoV outbreaks frequently occur in closed environments, such as schools, hospitals, and cruise ships, and often originate from contaminated groundwater 7 . NoV has been recognized as a major cause of morbidity and mortality from diarrheal diseases in all age groups 8 …”

Section: Introductionmentioning

confidence: 99%

Genotyping and traceability analysis of norovirus in Yantai between 2017 and 2019

Sun,

Niu,

Jin

et al. 2023

To investigate the diversity and evolution of noroviruses in Yantai in recent years, this study focused on the coat protein regions of norovirus‐positive samples with nucleic acid detection (cycle threshold) values below 30 between 2017 and 2019. A total of 81 sequences were obtained for genotyping. Initially, a high‐throughput sequencing approach was established to perform the whole‐genome sequencing of multiple typical diarrheal strains. Using bioinformatics software such as BEAST, recombinant variant analysis was performed for each genotype of the norovirus strains, and genetic evolutionary analysis was conducted for the dominant strain GII.4, as well as the rare variant GII.21. The results showed that there were multiple genotypes such as GI.3, GI.6, GI.7, GII.1, GII.2, GII.3, GII.4, GII.6, GII.13, GII.17, GII.21, and GIX.1 in the positive samples of norovirus from 2017 to 2019. GII.4 is characterized by diverse genotypes, with new changes in antigenic epitopes occurring during the course of the epidemic. This may have led to the emergence of a new pandemic. This suggests a need to strengthen surveillance. The results of this study suggest that attention should be paid to the predominant genotypes prevalent in neighboring countries and regions, and the safety supervision of imported food should be strengthened to aid in the prevention and control of related viruses.

“…Norovirus outbreaks have been reported frequently in closed environments, such as facilities, schools, hospitals and cruise ships and often originate from contaminated groundwater [4]. The incidence of norovirus among children is very high; norovirus causes 200 000 deaths in children younger than 5 years of age annually in developing countries [5]. The elderly and immunocompromised patients are also vulnerable to norovirus and are at risk of dying from infection [5].…”

Section: Introductionmentioning

confidence: 99%

“…The incidence of norovirus among children is very high; norovirus causes 200 000 deaths in children younger than 5 years of age annually in developing countries [5]. The elderly and immunocompromised patients are also vulnerable to norovirus and are at risk of dying from infection [5].…”

Section: Introductionmentioning

confidence: 99%

Complete sequence analysis of human norovirus GII.17 detected in South Korea

et al. 2019

Norovirus, a major cause of gastroenteritis in people of all ages worldwide, was first reported in South Korea in 1999. The most common causal agents of pediatric acute gastroenteritis are norovirus and rotavirus. While vaccination has reduced the pediatric rotavirus infection rate, norovirus vaccines have not been developed. Therefore, prediction and prevention of norovirus are very important. Norovirus is divided into genogroups GI–GVII, with GII.4 being the most prevalent. However, in 2012–2013, GII.17 showed a higher incidence than GII.4 and a novel variant, GII.P17-GII.17, appeared. In this study, 204 stool samples collected in 2013–2014 were screened by reverse transcriptase-polymerase chain reaction; 11 GI (5.39%) and 45 GII (22.06%) noroviruses were identified. GI.4, GI.5, GII.4, GII.6 and GII.17 were detected. The whole genomes of the three norovirus GII.17 were sequenced. The whole genome of GII.17 consists of three open reading frames of 5109, 1623 and 780 bp. Compared with 20 GII.17 strains isolated in other countries, we observed numerous changes in the protruding P2 domain of VP1 in the Korean GII.17 viruses. Our study provided genome information that might aid in epidemic prevention, epidemiology studies and vaccine development.