Yuanyun Ao1, Xin Cong1, Miao Jin1, Xiaoman Sun1, Xiaoman Wei2, Jinjin Wang3, Qing Zhang1, Jiao Song4, Jiemei Yu1, Jie Cui2, Jianxun Qi5, Ming Tan6, Zhaojun Duan1. 1. National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing. 2. Key Laboratory of Special Pathogens and Biosafety, Center for Emerging Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan. 3. College of Food Science and Technology, Shanghai Ocean University, Lanzhou. 4. School of Public Health, Gansu University of Chinese Medicine, Lanzhou. 5. Institute of Microbiology, Chinese Academy of Sciences, Beijing, China. 6. Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Ohio.
Abstract
Background: During 2016-2017, the previously rare GII.P16-GII.2 norovirus suddenly emerged as the predominant genotype causing gastroenteritis outbreaks in China and other countries. Its origin, phylodynamics, and mechanism behind the predominance remain unclear. Methods: Bayesian phylogenetic analyses were performed on 180 full capsid and 150 polymerase sequences of 2016-2017 GII.P16-GII.2 noroviruses in China, and those for all publicly available GII.P16 and GII.2 sequences. Saliva-based histo-blood group antigen (HBGA) binding assays and crystal structural analysis were conducted by using the P proteins of 2016-2017 GII.P16-GII.2 noroviruses. Results: The reemerging GII.P16-GII.2 norovirus showed a rapid genetic diversification after its emergence in 2012-2013. The antigenicity and HBGA binding profile of the early 2016-2017 and pre-2016 GII.2 noroviruses were similar. A further variant with a single Val256Ile mutation and the conventionally orientated Asp382 in the VP1 protein showed an expanded HBGA-binding spectrum. Mutations on the surface of polymerase that could alter its function were seen, which may help to accelerate the VP1 gene evolution to 5.5 × 10-3 substitutions per site per year. This virus can be traced back to Pearl River Delta, China. Conclusions: Our findings provide new insights into GII.2 norovirus epidemics and highlight the necessity of enhanced global surveillance for potential epidemics of rare-genotype noroviruses.
Background: During 2016-2017, the previously rare GII.P16-GII.2 norovirus suddenly emerged as the predominant genotype causing gastroenteritis outbreaks in China and other countries. Its origin, phylodynamics, and mechanism behind the predominance remain unclear. Methods: Bayesian phylogenetic analyses were performed on 180 full capsid and 150 polymerase sequences of 2016-2017 GII.P16-GII.2 noroviruses in China, and those for all publicly available GII.P16 and GII.2 sequences. Saliva-based histo-blood group antigen (HBGA) binding assays and crystal structural analysis were conducted by using the P proteins of 2016-2017 GII.P16-GII.2 noroviruses. Results: The reemerging GII.P16-GII.2 norovirus showed a rapid genetic diversification after its emergence in 2012-2013. The antigenicity and HBGA binding profile of the early 2016-2017 and pre-2016 GII.2 noroviruses were similar. A further variant with a single Val256Ile mutation and the conventionally orientated Asp382 in the VP1 protein showed an expanded HBGA-binding spectrum. Mutations on the surface of polymerase that could alter its function were seen, which may help to accelerate the VP1 gene evolution to 5.5 × 10-3 substitutions per site per year. This virus can be traced back to Pearl River Delta, China. Conclusions: Our findings provide new insights into GII.2 norovirus epidemics and highlight the necessity of enhanced global surveillance for potential epidemics of rare-genotype noroviruses.
Authors: Marta Diez-Valcarce; Maria Renee Lopez; Beatriz Lopez; Oneida Morales; Manuel Sagastume; Loren Cadena; Susan Kaydos-Daniels; Claudia Jarquin; John P McCracken; Joe P Bryan; Jan Vinjé Journal: J Clin Virol Date: 2019-03-09 Impact factor: 3.168
Authors: Shilu Mathew; Khalid Alansari; Maria K Smatti; Hassan Zaraket; Asmaa A Al Thani; Hadi M Yassine Journal: Viruses Date: 2019-04-29 Impact factor: 5.048