Temporal Dynamics of Norovirus GII.4 Variants in Brazil between 2004 and 2012
Temporal Dynamics of Norovirus GII.4 Variants in Brazil between 2004 and 2012
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DOI：
10.1371/journal.pone.0092988
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发表时间：
2014-03-25
期刊：
影响因子：
3.7
通讯作者：
Miagostovich, Marize Pereira
中科院分区：
文献类型：
--
作者：
Fioretti, Julia Monassa;Bello, Gonzalo;Miagostovich, Marize Pereira
诺如病毒（NoV）是急性胃肠炎暴发的主要原因，尽管存在广泛的遗传多样性，但基因型II.4是全球最流行的毒株。突变和同源重组被认为是推动GII.4划时代进化的机制，每隔1-3年就会出现新的变体，导致全球流行。没有数据报告沿着巴西特定时期GII.4变种的动态。因此，为了更好地了解这些变体在该国的行为，本研究的目的是评估9年期间5个巴西地区中3个地区的NoV GII.4变体的流通情况。共对147个样本进行了测序，亚结构域P2的系统发育分析表明，在此期间，有6个GII.4变体，Asia_2003，Hunter_2004，Den Haag_2006b，Yerseke_2006a，New Orleans_2009和Sydney_2012。最流行的变种是Den Haag_2006b，从2006年到2011年在巴西不同地区流行。用贝叶斯结合分析法计算出亚结构域P2的平均进化速率为7.3x10（-3）（5.85x10（-3）-8.82x10（-3）），地点/年份这些分析还表明，进化枝Den Haag_2006b在经历了一段时间的衰退后，在2005年和2008年经历了一次快速扩张。对巴西的NoV GII.4的时间动态的评价显示了与全球观测相似的模式，只有少数例外。这些数据突出了监测新的NoV GII.4菌株出现及其对急性胃肠炎病例影响的重要性。
Noroviruses (NoVs) are the major cause of acute gastroenteritis outbreaks, and, despite a wide genetic diversity, genotype II.4 is the most prevalent strain worldwide. Mutations and homologous recombination have been proposed as mechanisms driving the epochal evolution of the GII.4, with the emergence of new variants in 1-3-year intervals causing global epidemics. There are no data reporting the dynamics of GII.4 variants along a specific period in Brazil. Therefore, to improve the understanding of the comportment of these variants in the country, the aim of this study was to evaluate the circulation of NoV GII.4 variants during a 9-year period in 3 out of 5 Brazilian regions. A total of 147 samples were sequenced, and a phylogenetic analysis of subdomain P2 demonstrated the circulation of six GII.4 variants, Asia_2003, Hunter_2004, Den Haag_2006b, Yerseke_2006a, New Orleans_2009, and Sydney_2012, during this period. The most prevalent variant was Den Haag_2006b, circulating in different Brazilian regions from 2006 to 2011. A Bayesian coalescent analysis was used to calculate the mean evolutionary rate of subdomain P2 as 7.3x10(-3) (5.85x10(-3) -8.82x10(-3)) subst./site/year. These analyses also demonstrated that clade Den Haag_2006b experienced a rapid expansion in 2005 and another in 2008 after a period of decay. The evaluation of the temporal dynamics of NoV GII.4 in Brazil revealed a similar pattern, with few exceptions, to the worldwide observation. These data highlight the importance of surveillance for monitoring the emergence of new strains of NoV GII.4 and its impact on cases of acute gastroenteritis.