Silva Vanessa Cristina Martins, França Yasmin, Azevedo Lais Sampaio de, Guiducci Raquel, Villela Edlaine Faria de Moura, Luchs Adriana
Virology Center, Adolfo Lutz Institute, Sao Paulo 01246-902, Brazil.
Graduate Program in Sciences of the Center for Disease Control, São Paulo State Department of Health, Sao Paulo 01246-000, Brazil.
Viruses. 2025 Aug 11;17(8):1103. doi: 10.3390/v17081103.
In Brazil, molecular surveillance expanded after Rotarix™ vaccine introduction, alongside G2P[4] dominance. The G2P[6] genotype, despite sharing the same DS-1-like constellation as G2P[4] strains, remains rare. This retrospective study analyzed eight Brazilian G2P[6] strains (2012-2014) through RT-PCR and 11-segments sequencing, followed by phylogenetic analysis. Two distinct groups were identified: 2012-2013 strains (six) carried a DS-1-like backbone with the rare NSP4 E6 genotype, while 2014 strains (two) exhibited the classical DS-1-like constellation with E2. Phylogenetic analysis confirmed the two main clusters: 2012-2013 strains related to classical G2P[4] and uncommon global genotypes, and 2014 strains resembling emerging DS-1-like G1/G3/G8P[8] reassortants. The 2012-2013 strains clustered within G2-VP7 Lineage IVa, while the 2014 strains belonged to Lineage V, reflecting the global distribution of these variants. All VP4 genes were classified within the P[6]-Ia lineage, with phylogenetic analyses suggesting separate introductions from Asia and Africa. The E6 NSP4 gene segment identified in these strains has an undetermined origin and was not previously associated with G2P[6] strains in Brazil. Despite similarities to G2P[4], G2P[6] strains remain rare, with no genomic features explaining their limited spread. Phylogenetic data indicate multiple reassortment events and international viral exchange, highlighting Brazil's role in RVA diversity. Ongoing full-genome surveillance is crucial to track rare variants and assess their public health relevance.
在巴西，随着Rotarix™疫苗的引入，分子监测工作得到了扩展，与此同时G2P[4]占据主导地位。G2P[6]基因型尽管与G2P[4]毒株具有相同的DS-1样基因组合，但仍然罕见。这项回顾性研究通过逆转录聚合酶链反应（RT-PCR）和11个基因片段测序，对8株巴西G2P[6]毒株（2012 - 2014年）进行了分析，随后进行了系统发育分析。研究确定了两个不同的组：2012 - 2013年的毒株（6株）携带具有罕见NSP4 E6基因型的DS-1样主干，而2014年的毒株（2株）表现出带有E2的经典DS-1样基因组合。系统发育分析证实了两个主要聚类：2012 - 2013年的毒株与经典G2P[4]和不常见的全球基因型相关，2014年的毒株类似于新出现的DS-1样G1/G3/G8P[8]重配毒株。2012 - 2013年的毒株聚集在G2-VP7谱系IVa内，而2014年的毒株属于谱系V，反映了这些变异株的全球分布情况。所有VP4基因都归类于P[6]-Ia谱系，系统发育分析表明它们分别从亚洲和非洲引入。在这些毒株中鉴定出的E6 NSP4基因片段来源不明，此前在巴西未与G2P[6]毒株相关联。尽管与G2P[4]有相似之处，但G2P[6]毒株仍然罕见，没有基因组特征可以解释它们传播有限的原因。系统发育数据表明存在多次重配事件和国际病毒交换，突出了巴西在轮状病毒A多样性方面的作用。持续的全基因组监测对于追踪罕见变异株并评估其公共卫生相关性至关重要。
