Victorian Infectious Diseases Reference Laboratory, North Melbourne, Victoria, Australia.
J Med Virol. 2013 Aug;85(8):1433-43. doi: 10.1002/jmv.23633.
GII.b norovirus is an obligatory recombinant with an open reading frame (ORF) 1 comprising the GII.b genotype and the ORF 2 region corresponding to one of a number of other norovirus genotypes. GII.b is the second most common genotype after GII.4 associated with gastroenteritis outbreaks in Victoria, Australia. The study involved norovirus testing of 14,186 specimens from 2,743 Victorian gastroenteritis outbreaks in the period 2002-2011. The noroviruses identified were further characterized by nucleotide sequencing and phylogenetic analysis. In the period 2002-2005, 21 GII.b norovirus outbreaks were identified, with the GII.b ORF 2 recombinant genotypes comprising GII.1 (47.6%), GII.3 (47.6%), and GII.13 (4.8%). For the period 2006-2011, 56 GII.b norovirus outbreaks were identified. In 51 of these, the ORF 2 genotype was identified, and comprised GII.1 (2.0%), GII.3 (94.1%), GII.13 (2.0%), and GII.21 (2.0%). GII.b norovirus outbreaks could occur in a range of settings involving individuals with a broad range of ages. However, GII.b/GII.3 norovirus tended to occur in a younger demographic and all outbreaks involving specifically children's settings had the GII.b/GII.3 genotype. Nucleotide sequencing studies demonstrated major changes in both the ORF 1 and ORF 2 regions of the GII.b/GII.3 noroviruses but not in the GII.b/GII.1 and GII.b/GII.13 noroviruses when the noroviruses for the two time periods 2002-2005 and 2006-2011 were compared. The findings suggest nucleotide changes in the pre-existing GII.b/GII.3 noroviruses resulted in a more virulent form.
GI.b 诺如病毒是一种强制性重组病毒，其开放阅读框（ORF）1 包含 GI.b 基因型，ORF 2 区域对应于多种其他诺如病毒基因型之一。GI.b 是继 GI.4 之后澳大利亚维多利亚州与肠胃炎爆发相关的第二常见基因型。本研究涉及对 2002 年至 2011 年期间维多利亚州 2743 起肠胃炎爆发的 14186 个样本进行诺如病毒检测。通过核苷酸测序和系统进化分析进一步对鉴定出的诺如病毒进行特征描述。在 2002 年至 2005 年期间，鉴定出 21 起 GI.b 诺如病毒爆发，其中 GI.b ORF 2 重组基因型包括 GI.1（47.6%）、GI.3（47.6%）和 GI.13（4.8%）。在 2006 年至 2011 年期间，鉴定出 56 起 GI.b 诺如病毒爆发。在其中 51 起爆发中，鉴定出 ORF 2 基因型，包括 GI.1（2.0%）、GI.3（94.1%）、GI.13（2.0%）和 GI.21（2.0%）。GI.b 诺如病毒爆发可能发生在涉及年龄广泛的人群的多种环境中。然而，GI.b/GII.3 诺如病毒往往发生在年龄较小的人群中，并且所有涉及特定儿童环境的爆发都具有 GI.b/GII.3 基因型。核苷酸测序研究表明，当比较 2002 年至 2005 年和 2006 年至 2011 年两个时期的诺如病毒时，GI.b/GII.3 诺如病毒的 ORF 1 和 ORF 2 区域发生了重大变化，但 GI.b/GII.1 和 GI.b/GII.13 诺如病毒没有发生变化。研究结果表明，先前存在的 GI.b/GII.3 诺如病毒中的核苷酸变化导致了更具毒性的形式。
