Analysis of the genetic characteristics of GⅡ.P16 norovirus outbreaks in Qingdao
10.3760/cma.j.cn112309-20240522-00174
- VernacularTitle:青岛市诺如病毒暴发疫情中GⅡ.P16型变异株的基因特征分析
- Author:
Dan ZHAO
1
;
Song LIU
1
;
Zhilei SU
1
;
Xiaoyan SHI
1
;
Zhaoguo WANG
1
Author Information
1. 青岛市疾病预防控制中心（青岛市预防医学研究院）病毒所，青岛 266033
- Publication Type:Journal Article
- Keywords:
Norovirus;
Outbreak;
GⅡ.P16
- From:
Chinese Journal of Microbiology and Immunology
2025;45(4):310-316
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the molecular epidemiological characteristics of norovirus (NoV) outbreaks in Qingdao.Methods:Anus swab specimens were collected during NoV outbreaks from 2016 to 2020 and detected by real-time RT-PCR. Full length of RNA-dependent RNA polymerase (RdRp) and VP1 gene were amplified by RT-PCR for sequencing, evolutionary analysis, and homology modeling.Results:A total of 65 NoV outbreaks were reported, with 59 outbreaks occurring in kindergartens and primary/secondary schools, showing a double peak epidemic pattern, with peaks occurring from March to May and from October to December. A GⅡ.P16 outbreak in Qingdao first appeared in March 2017 and became the predominant strains from 2017 to 2020(67.9%, 38/56), including two genotypes: GⅡ.2[P16] (97.4%, 37/38) and GⅡ.4 Sydney[P16] (2.6%, 1/38). The GⅡ.2[P16] strains isolated were closely related to the 2010-2012 GⅡ.2[P16] strains, from whichi they probably evolved. The GⅡ.2[P16] Qingdao strains shared five common substitutions, namely D173E (motif F), V175I (motif F), S293T, K357Q (motif D), and T360A (motif D). The RdRp nucleotide consistency between GⅡ.2[P16] and GⅡ.4 Sydney[P16] was greater than 95%, and there were mainly four amino acid differences, namely K54R, V125A, A312T, and K457R.The evolutionary variation of GⅡ.2[P16] VP1 was minimal, with only a few amino acid substitutions taking place. The main functional variations of GⅡ.4 Sydney[P16] VP1 included R297H (epitope A), D310N (NERK motif), D372N (epitope A), and R373H (positive selection site).Conclusions:GⅡ.P16 NoV is the predominant epidemic strain of ad norovirus outbreaks in Qingdao from 2016 to 2020, and continuous monitoring of its epidemic trend and in-depth study of its evolutionary mechanism are necessary.
