title: Emergence of a new norovirus genotype II.4 variant associated with global outbreaks of gastroenteritis.
abstract: Norovirus (NoV) is highly infectious and is the major cause of outbreak gastroenteritis in adults, with pandemic spread of the virus being reported in 1995 and 2002. The NoV genome is genetically diverse, which has hampered development of sensitive molecular biology-based methods. In this study we report on a nested reverse transcriptase PCR (nRT-PCR) that was designed to amplify the highly conserved 3' end of the polymerase region and the 5' end of the capsid gene of NoV genogroup II (GII). The nRT-PCR was validated with strains isolated from sporadic and outbreak cases between 1997 and 2004 in New South Wales, Australia. Phylogenetic analysis identified six genotypes circulating in New South Wales, GII.1, GII.3, GII.4, GII.6, GII.7, and GII.10, with GII.4 being the predominant genotype. In 2004, there was a marked increase in NoV GII activity in Australia, with a novel GII.4 variant being identified as the etiological agent in 18 outbreaks investigated. This novel GII.4 variant, termed Hunter virus, differed by more than 5% at the amino acid level across the capsid from any other NoV strain in the GenBank and EMBL databases. The Hunter virus was subsequently identified as the etiological agent in large epidemics of gastroenteritis in The Netherlands, Japan, and Taiwan in 2004 and 2005.
authors.affiliation: School of Biotechnology and Biomolecular Sciences, Faculty of Science, University of New South Wales, Sydney 2052, Australia.
authors.forename: Rowena A
authors.initials: RA
authors.lastname: Bull
authors.forename: Elise T V
authors.initials: ET
authors.lastname: Tu
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: McIver
authors.forename: William D
authors.initials: WD
authors.lastname: Rawlinson
authors.forename: Peter A
authors.initials: PA
authors.lastname: White
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D020121:5' Untranslated Regions / Q000235:genetics; D001315:Australia / Q000453:epidemiology; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000821:virology; D036022:Capsid Proteins / Q000235:genetics; D004196:Disease Outbreaks; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology; D005838:Genotype; D014943:Global Health; D008969:Molecular Sequence Data; D029322:Norovirus / Q000145:classification* / Q000235:genetics*; D010802:Phylogeny; D012367:RNA, Viral / Q000032:analysis / Q000302:isolation & purification; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D036022:Capsid Proteins; D012367:RNA, Viral; D012324:RNA-Dependent RNA Polymerase