Laboratory of Comparative and Environmental Virology, Oswaldo Cruz Institute - FIOCRUZ, Av. Brasil 4365, Manguinhos, 21040-360 Rio de Janeiro, RJ, Brazil.
J Clin Virol. 2010 Apr;47(4):345-55. doi: 10.1016/j.jcv.2009.12.018. Epub 2010 Feb 4.
Group A rotavirus (RV-A) genotype P[8]G9 has emerged as one of the leading causes of gastroenteritis in children worldwide and currently is recognized as one of the five most common genotypes detected in humans. High intragenotype diversity in G9 RV-A has been observed, and nowadays, based on the genetic variability of the VP7 gene, six different phylogenetic lineages and eleven sublineages were described.
To study the degree of genetic variation and evolution of Brazilian P[8]G9 RV-A strains.
Phylogenetic analysis of 19 P[8]G9 RV-A strains isolated from 2004 to 2007 in five different Brazilian states was conducted using the NSP1, NSP3, NSP5, VP4 and VP7 genes. For the VP4 and VP7 genes, 3D protein structure predictions were generated to analyze the spatial distribution of amino acid substitutions observed in Brazilian strains.
Based on the phylogenetic analyses, all Brazilian strains clustered within lineage G9-III and P[8]-3 for VP7 and VP4, respectively, and were classified as genotype A1, T1 and H1 for the NSP1, NSP3 and NSP5 genes, respectively. Interestingly, all the strains isolated in Acre State (Northern Brazil) formed a closely related cluster clearly separated from the other Brazilian and prototype strains with regard to the five genes studied. Unique amino acid substitutions were observed in Acre strains in comparison with the prototype and Brazilian strains.
Inclusion of Acre strains in the phylogenetic analysis revealed the presence of a novel genetic variant and demonstrated a diversification of P[8]G9 rotaviruses in Brazil.
A 组轮状病毒（RV-A）基因型 P[8]G9 已成为全球儿童胃肠炎的主要病因之一，目前被认为是人类最常见的五种基因型之一。已观察到 G9 RV-A 具有高度的基因内多样性，如今，根据 VP7 基因的遗传变异性，已描述了六个不同的系统发育谱系和十一个亚谱系。
研究巴西 P[8]G9 RV-A 株的遗传变异和进化程度。
对 2004 年至 2007 年间在巴西五个不同州分离的 19 株 P[8]G9 RV-A 株进行了 NSP1、NSP3、NSP5、VP4 和 VP7 基因的系统发育分析。对于 VP4 和 VP7 基因，生成了 3D 蛋白结构预测，以分析在巴西株中观察到的氨基酸取代的空间分布。
基于系统发育分析，所有巴西株均在 VP7 和 VP4 上分别聚类于谱系 G9-III 和 P[8]-3，在 NSP1、NSP3 和 NSP5 基因上分别归类为基因型 A1、T1 和 H1。有趣的是，所有在巴西阿克里州（北部）分离的株均形成了一个密切相关的聚类，与其他巴西和原型株在研究的五个基因上明显分离。与原型株和巴西株相比，阿克里株观察到独特的氨基酸取代。
将阿克里株纳入系统发育分析显示存在新型遗传变异，并证明了巴西 P[8]G9 轮状病毒的多样化。
