title: [Study on norovirus GII.4/Sydney 2012 variant in China].
abstract: OBJECTIVE
  To study the nucleotide and amino acid sequences of norovirus G II.4/Sydney 2012 variants, in China.
  
  
  METHODS
  Twenty-two stool specimens, confirmed as G II.4/Sydney 2012- positive were collected from Beijing in the winter of 2012-2013. RT-PCR was performed to target the complete capsid gene. G II.4/Sydney 2012 strains from other regions in China were searched and obtained from the GenBank. Nucleotide and amino acid sequences of G II.4/Sydney 2012 strains were analyzed, using the CLUSTAL X(Version 1.83)and followed by phylogenetic analysis using Mega version 5.1.
  
  
  RESULTS
  The complete major capsid nucleotide sequences of thirty-eight G II.4/ Sydney 2012 strains from seven regions in China were obtained. The VP1 nucleotide and amino acid sequences diversity were 0.1%-3.3% and 0-3.1%, respectively. Result from phylogenetic analysis demonstrated that the G II.4/Sydney 2012 variant shared a common ancestor with both the dominant norovirus G II.4 variants Apeldoorn 2008 and the New Orleans 2009. G II.4/Sydney 2012 variants appeared to have had two A/D/E site combinations at the amino acid level, TSRN-GTT-SNT and TSRN-STT-SNT.
  
  
  CONCLUSIONS
  G II.4/Sydney 2012 variant had been circulating in many regions in China. There seemed a high nucleotide and amino acid identity among G II.4/Sydney 2012 strains collected from China. G II.4/Sydney 2012 variants showed different A/D/E site combination from other pandemic G II.4 variants.
authors.affiliation: Department of Infectious Diseases, People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Mai
authors.affiliation: Department of Infectious Diseases, People's Hospital, Peking University, Beijing 100044, China. Email: gaoyan6384@163.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Institute of Hepatology, People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Xiaoben
authors.initials: X
authors.lastname: Pan
authors.affiliation: Institute of Hepatology, People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Jinchao
authors.initials: J
authors.lastname: Han
authors.affiliation: Institute of Hepatology, People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Cong
authors.affiliation: Department of Infectious Diseases, People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Lai
authors.initials: L
authors.lastname: Wei
mesh_terms: D000595:Amino Acid Sequence; D017250:Caliciviridae Infections / Q000453:epidemiology*; D036022:Capsid Proteins / Q000235:genetics; D002681:China / Q000453:epidemiology; D003967:Diarrhea / Q000821:virology; D005838:Genotype; D006801:Humans; D029322:Norovirus / Q000235:genetics* / Q000302:isolation & purification*; D010802:Phylogeny
chemical_list: D036022:Capsid Proteins