Study on norovirus GⅡ.4/Sydney 2012 variant in China / 中华流行病学杂志

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 Apeldoom 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.Conclusion 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.