Occurrence of novel GII.17 and GII.21 norovirus variants in the coastal environment of South Korea in 2015

Abstract

Human norovirus (HNoV), a positive-sense RNA virus, is the main causative agent of acute viral gastroenteritis. Multiple pandemic variants of the genogroup II genotype 4 (GII.4) of NoV have attracted great attention from researchers worldwide. However, novel variants of GII.17 have been overtaking those pandemic variants in some areas of East Asia. To investigate the environmental occurrence of GII in South Korea, we collected water samples from coastal streams and a neighboring waste water treatment plant in North Jeolla province (in March, July, and December of 2015). Based on capsid gene region C analysis, four different genotypes (GII.4, GII.13, GII.17, and GII.21) were detected, with much higher prevalence of GII.17 than of GII.4. Additional sequence analyses of the ORF1-ORF2 junction and ORF2 from the water samples revealed that the GII.17 sequences in this study were closely related to the novel strains of GII.P17-GII.17, the main causative variants of the 2014–2015 HNoV outbreak in China and Japan. In addition, the GII.P21-GII.21 variants were identified in this study and they had new amino acid sequence variations in the blockade epitopes of the P2 domain. From these results, we present two important findings: 1) the novel GII.P17-GII.17 variants appeared to be predominant in the study area, and 2) new GII.21 variants have emerged in South Korea.

A Targeted Metagenomics Approach to Study the Diversity of Norovirus GII in Shellfish Implicated in Outbreaks

“…GII.17 and GII.P17 sequences detected in all samples were closer to the emerging Kawasaki strains from 2014 and 2015 ( Figure 3). This confirms previous reports that this GII.17[P17] variant contaminated the environment and shellfish during winter 2015-2016 when it spread worldwide [19,[44][45][46]. Importantly, for two outbreaks, GII.17 was identified in the stools of patients (Table 1), and, using our approach, in the corresponding shellfish samples (Table 3).…”

GII.13/21 Noroviruses Recognize Glycans with a Terminal β-Galactose via an Unconventional Glycan Binding Site

“…This mucin core 2-containing mucus may act as an attachment factor for GII.13/21 NoVs, similar to HBGAs for other huNoVs. However, except for a slight increase of GII.13 prevalence in Nepalese children between 2005 and 2011 (31), the worldwide prevalence of GII.13/21 NoVs appears not to be high according to previous reports (32, 33) and the NoroNet/CaliciNet public databases (34). This seems conflict with the fact that GII.13/21 P domains bound the majority of human saliva samples tested in this study, which are rich in β-Gal-containing glycans.…”

Characterization of Norovirus and Other Human Enteric Viruses in Sewage and Stool Samples Through Next-Generation Sequencing

“…The two other methods also allowed to characterize some norovirus sequence, all of them being already reported in the NoroNet network (van Beek et al 2018). Beside the ubiquitous GII.4 strains that have been reported worldwide, it was interesting to detect the GII.P17-GII.17 strain that caused several gastroenteritis outbreaks in multiple countries during this sampling period (Matsushima et al 2015; Koo et al 2017). In this regard, a complete characterization of detected viruses is important to identify new strains and thus to help risk manager to take measure to prevent further distribution (Cocolin et al 2018).…”