Avian Influenza Research & Diagnostic Division, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea.
Department of Pathobiology and Veterinary Science, The University of Connecticut, 61 North Eagleville Road, Unit-3089, Storrs, CT 06269, United States.
Infect Genet Evol. 2020 Mar;78:104056. doi: 10.1016/j.meegid.2019.104056. Epub 2019 Nov 1.
Since 2017, clade 2.3.4.4b H5N6 highly pathogenic avian influenza viruses (HPAIVs) have been detected over a broad geographic region, including Eurasia. These viruses have evolved through reassortment with Eurasian low pathogenic avian influenza viruses (LPAIVs), resulting in multiple genotypes. Here, we sequenced the full-length genome of 15 H5N6 HPAIVs collected from wild birds and poultry farms in South Korea from January to March 2018. A comparative phylogenetic analysis was then conducted. Three distinct genotypes were identified in South Korea during 2017/2018, including a novel reassortant genotype, H214. The novel reassortant H5N6 viruses isolated in this study possessed PB2, PA, and NP gene segments of Eurasian LPAIV on a genetic backbone of the H35-like genotype, which was identified in Korea and the Netherlands during 2017. Bayesian molecular clock analysis suggested that the novel reassortant viruses were generated most likely during the fall migration/wintering season of migratory waterfowl in 2017. Considering the continued emergence and spread of clade 2.3.4.4 HPAIV, enhanced surveillance of wild waterfowl is needed for early detection of HPAIV incursions.
自 2017 年以来，包括欧亚大陆在内的广泛地理区域都检测到了 2.3.4.4b 分支的 H5N6 高致病性禽流感病毒（HPAIV）。这些病毒通过与欧亚低致病性禽流感病毒（LPAIV）重组而进化，产生了多种基因型。在这里，我们对 2018 年 1 月至 3 月期间从韩国野鸟和家禽养殖场收集的 15 株 H5N6 HPAIV 的全长基因组进行了测序。然后进行了比较系统发育分析。在 2017/2018 年期间，韩国确定了三种不同的基因型，包括一种新型重组基因型 H214。本研究分离的新型重组 H5N6 病毒在 PB2、PA 和 NP 基因片段上具有欧亚 LPAIV 的遗传背景，而在 2017 年韩国和荷兰也发现了这种背景。贝叶斯分子钟分析表明，新型重组病毒很可能是在 2017 年迁徙水禽的秋季迁徙/冬季形成的。考虑到 2.3.4.4 分支的 HPAIV 持续出现和传播，需要加强对野生水禽的监测，以便早期发现 HPAIV 的入侵。
