Jun Zhang1, Zhen Shen2, Zhaoqin Zhu3, Wanju Zhang3, Huifen Chen4, Fangxing Qian5, Haili Chen3, Gang Wang6, Moying Wang6, Yunwen Hu7, Zhenghong Yuan8. 1. Department of Laboratory Medicine, Shanghai First Maternity and Infant Hospital, Tongji University, Shanghai, China; Department of Clinical Laboratory, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China. Electronic address: zhangjun@51mch.com. 2. Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China; Department of Clinical Laboratory, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China. 3. Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China. 4. Department of Laboratory Medicine, Shanghai First Maternity and Infant Hospital, Tongji University, Shanghai, China. 5. Department of Infectious Diseases, Tongren Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China. 6. Department of Clinical Laboratory, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China. 7. Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China. Electronic address: ywhu0117@126.com. 8. Key Lab of Medical Molecular Virology, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, China.
Abstract
BACKGROUND: The pattern of epochal evolution of NoV is ongoing, while novel GII.4 variants emerge and cause new pandemics. Since, the emergence in March 2012, Sydney_2012 had replaced GII.4-2009 as the primary NoV strain in most countries in the northern hemisphere by November 2012. OBJECTIVES: To determine the genotype distribution around the emergence of Sydney_2012 and to investigate the underlying evolution mechanisms of the contemporary GII.4 strains. STUDY DESIGN: From January 2012 to December 2013, molecular epidemiology of norovirus in 846 adults (≥16 years) in Shanghai were conducted. The VP1 proteins of the contemporary GII.4 strains (Den_Haag_2006b, New_Orleans_2009 and Sydney_2012) were expressed in vitro and purified. Receptor binding patterns of these three epidemic strains were determined through histo-blood group antigen (HBGA) binding assays. Convalescent serum from patients infected with GII.4 epidemic strains were employed to investigate the role of antigenic drift in the persistence of GII.4 epidemic strains through receptor-binding blockade assays. RESULTS: Epidemiological studies revealed that Sydeny_2012 has completely replaced Den_Haag_2006b and New_Orleans_2009 and has been the dominant circulating strain in Shanghai since its emergence in October 2012. Interestingly, Den_Haag_2006b and New_Orleans_2009 have been co-circulating in Shanghai before the emergence of Sydeny_2012. The contemporary GII.4 epidemic norovirus strains displayed commonly high tropism to the histo-blood group antigen receptors, whereas Sydeny_2012 was antigenically different from Den_Haag_2006b and New_Orleans_2009. CONCLUSIONS: Antigenic drift, rather than receptor switch, played a key role in the emergence and spreading of Sydney_2012. The contemporary GII.4 strains were evolving via epochal evolution without altered ligand binding profiles.
BACKGROUND: The pattern of epochal evolution of NoV is ongoing, while novel GII.4 variants emerge and cause new pandemics. Since, the emergence in March 2012, Sydney_2012 had replaced GII.4-2009 as the primary NoV strain in most countries in the northern hemisphere by November 2012. OBJECTIVES: To determine the genotype distribution around the emergence of Sydney_2012 and to investigate the underlying evolution mechanisms of the contemporary GII.4 strains. STUDY DESIGN: From January 2012 to December 2013, molecular epidemiology of norovirus in 846 adults (≥16 years) in Shanghai were conducted. The VP1 proteins of the contemporary GII.4 strains (Den_Haag_2006b, New_Orleans_2009 and Sydney_2012) were expressed in vitro and purified. Receptor binding patterns of these three epidemic strains were determined through histo-blood group antigen (HBGA) binding assays. Convalescent serum from patients infected with GII.4 epidemic strains were employed to investigate the role of antigenic drift in the persistence of GII.4 epidemic strains through receptor-binding blockade assays. RESULTS: Epidemiological studies revealed that Sydeny_2012 has completely replaced Den_Haag_2006b and New_Orleans_2009 and has been the dominant circulating strain in Shanghai since its emergence in October 2012. Interestingly, Den_Haag_2006b and New_Orleans_2009 have been co-circulating in Shanghai before the emergence of Sydeny_2012. The contemporary GII.4 epidemic norovirus strains displayed commonly high tropism to the histo-blood group antigen receptors, whereas Sydeny_2012 was antigenically different from Den_Haag_2006b and New_Orleans_2009. CONCLUSIONS: Antigenic drift, rather than receptor switch, played a key role in the emergence and spreading of Sydney_2012. The contemporary GII.4 strains were evolving via epochal evolution without altered ligand binding profiles.
Authors: Shu-Wen Qin; Ta-Chien Chan; Jian Cai; Na Zhao; Zi-Ping Miao; Yi-Juan Chen; She-Lan Liu Journal: Int J Environ Res Public Health Date: 2017-11-03 Impact factor: 3.390