Luchs Adriana, do Carmo Sampaio Tavares Timenetsky Maria
Enteric Diseases Laboratory, Virology Center, Adolfo Lutz Institute, Av Dr. Arnaldo, no. 355, Centro de Virologia, Cerqueira César, São Paulo, 01246-902, Brazil,
Mol Genet Genomics. 2015 Jun;290(3):969-86. doi: 10.1007/s00438-014-0971-9. Epub 2014 Dec 11.
Group C rotaviruses (RVC) cause gastroenteritis in humans and animals worldwide, and the evidence for a possible zoonotic role has been recently provided. To gain information on the genetic diversity and relationships between human and animal RVC, we sequenced the VP4, VP7, and NSP4 genes of 12, 19, and 15 human strains, respectively, detected in São Paulo state during historical (1988 and 1993) and recent (2007 and 2008) Brazilian rotavirus surveillance. All RVC strains analyzed in the present study grouped into human genotype (G4-P[2]-E2), and did not show any evidence of animal ancestry. Phylogenetic analysis showed that RVC samples detected in 1988 and 1993 clustered together with strains from distinct continents, indicating that historical RVC strains circulating in São Paulo were closely related to those strains circulating worldwide. All three genes (VP7, VP4 and NSP4) of São Paulo RVC strains isolated in 2007-2008 exhibited close phylogenetic relationship with human RVC strains isolated in China and Japan, suggesting that they are genetically linked, and that a gene flow could be occurring between this Asian countries and Brazil. We identified two distinct clusters in the NSP4 phylogenetic tree. One cluster formed exclusively by human Brazilian strains detected in 1997 and 2003-2004 in Rio de Janeiro, Bahia, and Rio Grande do Sul states (Subgroup II) previously described in a different study, that displayed low sequence identities to other human strains formerly published, and to the Brazilian RVC strains (Subgroup I) characterized in the present study. These data suggests the circulation of two genetic profiles of the NSP4 gene in Brazil. High sequence diversity in NSP4 gene was previously reported in Asia, and additional diversity in NSP4 RVC strains spreading in the world should be expected. More in-depth molecular and epidemiological analysis of human RVC throughout the world will be needed to understand their diversity and clarify their evolution, as well as to develop classifications schemes.
C组轮状病毒（RVC）在全球范围内可导致人类和动物患肠胃炎，最近已有证据表明其可能具有人畜共患病的作用。为了解人类和动物RVC之间的遗传多样性及关系，我们分别对在巴西圣保罗州历史时期（1988年和1993年）以及近期（2007年和2008年）轮状病毒监测中检测到的12株、19株和15株人类毒株的VP4、VP7和NSP4基因进行了测序。本研究中分析的所有RVC毒株均归为人类基因型（G4-P[2]-E2），未显示出任何动物起源的迹象。系统发育分析表明，1988年和1993年检测到的RVC样本与来自不同大陆的毒株聚集在一起，这表明在圣保罗州流行的历史RVC毒株与全球流行的毒株密切相关。2007 - 2008年在圣保罗分离出的RVC毒株的所有三个基因（VP7、VP4和NSP4）与在中国和日本分离出的人类RVC毒株呈现出密切的系统发育关系，这表明它们在基因上存在联系，并且在这些亚洲国家和巴西之间可能正在发生基因流动。我们在NSP4系统发育树中鉴定出两个不同的簇。一个簇完全由1997年以及2003 - 2004年在里约热内卢、巴伊亚和南里奥格兰德州检测到的巴西人类毒株组成（第二亚组），该亚组在之前的一项不同研究中已有描述，与之前发表的其他人类毒株以及本研究中鉴定的巴西RVC毒株（第一亚组）显示出较低的序列同一性。这些数据表明巴西存在NSP4基因的两种遗传谱系在传播。此前在亚洲报道了NSP4基因的高度序列多样性，预计在全球传播的NSP4 RVC毒株中还会有更多的多样性。需要对全球范围内的人类RVC进行更深入的分子和流行病学分析，以了解它们的多样性、阐明其进化过程，并制定分类方案。
