Laboratório de Virologia Clínica e Molecular do Instituto de Ciências Biomédicas (ICB-II), Universidade de São Paulo, São Paulo, SP, Brazil.
Laboratório de Ornitologia e Animais Marinhos (LOAM), Universidade do Vale do Rio dos Sinos, UNISINOS, São Leopoldo, RS, Brazil.
Influenza Other Respir Viruses. 2018 Mar;12(2):220-231. doi: 10.1111/irv.12519. Epub 2017 Dec 15.
There is insufficient knowledge about the relation of avian influenza virus (AIV) to migratory birds in South America. Accordingly, we studied samples obtained over a 4-year period (2009-2012) from wild birds at a major wintering site in southern Brazil.
We obtained 1212 oropharyngeal/cloacal samples from wild birds at Lagoa do Peixe National Park and screened them for influenza A virus by RT-PCR amplification of the matrix gene. Virus isolates were subjected to genomic sequencing and antigenic characterization.
Forty-eight samples of 1212 (3.96%) contained detectable influenza virus RNA. Partial viral sequences were obtained from 12 of these samples, showing the presence of H2N2 (1), H6Nx (1), H6N1 (8), H9N2 (1), and H12N5 (1) viruses. As H6 viruses predominated, we generated complete genomes from all 9 H6 viruses. Phylogenetic analyses showed that they were most similar to viruses of South American lineage. The H6N1 viruses caused no disease signs in infected ferrets and, despite genetic differences, were antigenically similar to North American isolates.
Lagoa do Peixe National Park is a source of multiple AIV subtypes, with the levels of influenza virus in birds being highest at the end of their wintering period in this region. H6N1 viruses were the predominant subtype identified. These viruses were more similar to viruses of South American lineage than to those of North American lineage.
人们对禽流感病毒（AIV）与南美的候鸟之间的关系知之甚少。因此，我们研究了在巴西南部一个主要的候鸟越冬地，于 4 年期间（2009-2012 年）从野生鸟类身上获得的样本。
我们从 Lagoa do Peixe 国家公园的野生鸟类身上获得了 1212 份口咽/泄殖腔样本，并通过 RT-PCR 扩增基质基因对流感 A 病毒进行了筛查。对病毒分离株进行了基因组测序和抗原特性分析。
在 1212 份样本中，有 48 份（3.96%）含有可检测到的流感病毒 RNA。从其中的 12 份样本中获得了部分病毒序列，显示存在 H2N2（1）、H6Nx（1）、H6N1（8）、H9N2（1）和 H12N5（1）病毒。由于 H6 病毒占主导地位，我们从所有 9 株 H6 病毒中生成了完整的基因组。系统进化分析表明，它们与南美的病毒谱系最为相似。H6N1 病毒在感染的雪貂中未引起疾病迹象，尽管存在遗传差异，但在抗原性上与北美的分离株相似。
Lagoa do Peixe 国家公园是多种 AIV 亚型的来源地，在该地区候鸟越冬期结束时，鸟类中的流感病毒水平最高。H6N1 病毒是鉴定出的主要亚型。这些病毒与南美的病毒谱系更为相似，而与北美的病毒谱系相似性较低。
