Phan Tung Gia, Kaneshi Kunio, Ueda Yuichi, Nakaya Shigekazu, Nishimura Shuichi, Yamamoto Atsuko, Sugita Kumiko, Takanashi Sayaka, Okitsu Shoko, Ushijima Hiroshi
Department of Developmental Medical Sciences, Institute of International Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
J Med Virol. 2007 Sep;79(9):1388-400. doi: 10.1002/jmv.20924.
Norovirus is one of the most common causes of nonbacterial gastroenteritis in humans. A total of 603 fecal specimens collected from sporadic pediatric cases of acute gastroenteritis in Japan from 2004 to 2005 were tested for the presence of norovirus by RT-PCR. It was found that 51 (8.5%) specimens were positive for norovirus. The norovirus genotypes detected in this study were GII/1, GII/2, GII/3, GII/4, GII/6, and GII/7. Of these, GII/3 was the most predominant (52.9%), followed by GII/4 (37.2%) and others. It was noticed that four distinct types of recombinant noroviruses were co-circulating and the variant norovirus GIIb suddenly emerged to be the leading strain in Japan for the first time. A novel norovirus nomenclature was proposed, in which worldwide noroviruses were classified into seven distinct genogroups (I-VII). Norovirus GI and GII consisted of 16 genotypes with 32 subgenotypes and 23 genotypes with 34 subgenotypes, respectively. Of note, human and porcine noroviruses had a close genetic relationship within GII. Interestingly, multiple short amino acid motifs located at N terminus, S domain, P1 domain, P2 domain, and C terminus of capsid gene correctly defined the phylogenetic norovirus genogroups, genotypes, and subgenotypes. Another interesting feature of the study was the identification of eight hitherto unreported recombinant noroviruses. It was noteworthy that three different types (intergenogroup, intergenotype, and intersubgenotype) of recombination in noroviruses were also found. This is the first report to demonstrate the existence of intergenogroup and intersubgenotype recombinations in noroviruses and highlights a possible route of zoonoses in humans because porcine, bovine and murine noroviruses belong to genogroups II, III, and V, respectively.
诺如病毒是人类非细菌性肠胃炎最常见的病因之一。对2004年至2005年从日本散发性小儿急性肠胃炎病例中收集的603份粪便标本进行逆转录聚合酶链反应检测，以确定是否存在诺如病毒。结果发现，51份（8.5%）标本诺如病毒呈阳性。本研究中检测到的诺如病毒基因型为GII/1、GII/2、GII/3、GII/4、GII/6和GII/7。其中，GII/3最为常见（52.9%），其次是GII/4（37.2%）及其他基因型。研究发现，四种不同类型的重组诺如病毒共同传播，变异诺如病毒GIIb首次突然成为日本的主要毒株。有人提出了一种新的诺如病毒命名法，将全球诺如病毒分为七个不同的基因组（I-VII）。诺如病毒GI和GII分别由16个基因型和32个亚型以及23个基因型和34个亚型组成。值得注意的是，人类和猪诺如病毒在GII内具有密切的遗传关系。有趣的是，衣壳基因N端、S结构域、P1结构域、P2结构域和C端的多个短氨基酸基序正确地定义了诺如病毒的系统发育基因组、基因型和亚型。该研究的另一个有趣特征是鉴定出八种此前未报告的重组诺如病毒。同样值得注意的是，还发现了诺如病毒三种不同类型的重组（基因组间、基因型间和亚型间）。这是首次证明诺如病毒存在基因组间和亚型间重组的报告，并突出了人兽共患病在人类中的一种可能途径，因为猪、牛和鼠诺如病毒分别属于基因组II、III和V。
