This Article Full Text (PDF) Other Versions of this Article: JVI.00897-08v1 JVI.00897-08v2 82/22/11247    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Google Scholar Articles by Motomura, K. PubMed PubMed Citation Articles by Motomura, K.

 Previous Article  |  Next Article 

J. Virol. doi:10.1128/JVI.00897-08
Copyright (c) 2008, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Identification of Monomorphic and Divergent Haplotypes in 2006/2007 Norovirus GII/4 Epidemic Population by Genome-wide Tracing of Evolutionary History

Center for Pathogen Genomics, National Institute of Infectious Diseases, Tokyo 208-0011, Japan; Department of Virology II, National Institute of Infectious Diseases, Tokyo 208-0011, Japan; Sakai City Institute of Public Health, Osaka 590-0953, Japan

^* To whom correspondence should be addressed. Email: hirosato{at}nih.go.jp.

	Abstract

Our norovirus (NoV) surveillance group reported a more than four-fold increase in NoV infection in Japan during winter 2006/2007 compared to the previous winter. Because the increase was not linked to changes in the surveillance system, we suspected the emergence of new NoV GII/4 epidemic variants. To obtain information on viral changes, we conducted full-length genomic analysis. Stool specimens from 55 acute gastroenteritis patients of various ages were collected at 11 sites in Japan between May 2006 and January 2007. Direct sequencing of long PCR products revealed 37 GII/4 genome sequences. Phylogenetic study of viral genome and partial sequences showed that the two new GII/4 variants in Europe, termed 2006a and 2006b, initially coexisted as minorities in early 2006 in Japan, and that 2006b alone had dominated over the resident GII/4 variants during 2006. A combination of phylogenetic and entropy analyses revealed for the first time the unique amino acid substitutions in all 8 proteins of the new epidemic strains. These data and computer-assisted structural study of NoV capsid protein are compatible with a model of antigenic drift with tuning of the structure-functions of multiple proteins for the global outgrowth of new GII/4 variants. The availability of comprehensive information on genome sequences and unique protein changes of the recent global epidemic variants will allow studies of diagnostic assays, molecular epidemiology, molecular biology, and adaptive changes of NoV in nature.