School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
Agriculture, Fisheries and Conservation Department, Government of the Hong Kong Special Administrative Region, Hong Kong, China.
Virol J. 2024 Jul 7;21(1):153. doi: 10.1186/s12985-024-02423-w.
Wild waterfowl serve as a reservoir of some astroviruses. Fecal samples from wild waterfowl collected at Hong Kong's Marshes were tested using pan-astrovirus reverse transcription-PCR. Positive samples underwent subsequent host identification using DNA barcoding. Based on deduced partial sequences, noteworthy samples from three astrovirus groups (mammalian, avian and unclassified astroviruses) were further analyzed by next-generation sequencing. One sample of Avastrovirus 4 clade, MP22-196, had a nearly complete genome identified. The results of ORF2 phylogenetic analysis and genetic distance analysis indicate that Avastrovirus 4 is classified as a distinct subclade within Avastrovirus. MP22-196 has typical astrovirus genome characteristics. The unique characteristics and potential differences of this genome, compared to other avian astrovirus sequences, involve the identification of a modified sgRNA sequence situated near the ORF2 start codon, which precedes the ORF1b stop codon. Additionally, the 3' UTR of MP22-196 is shorter than other avian astroviruses. This study expands our understanding of the Avastrovirus 4 clade.
野生水禽是一些星状病毒的储存宿主。从香港湿地采集的野生水禽粪便样本，经 pan-astrovirus 逆转录-PCR 检测呈阳性。随后，利用 DNA 条形码对阳性样本进行宿主鉴定。根据部分推导序列，对来自三个星状病毒群（哺乳动物、鸟类和未分类星状病毒）的有意义样本进行下一代测序进一步分析。一株 Avastrovirus 4 分支的样本 MP22-196，鉴定出了一个近乎完整的基因组。ORF2 系统发育分析和遗传距离分析的结果表明，Avastrovirus 4 被归类为 Avastrovirus 中的一个独特亚分支。MP22-196 具有典型的星状病毒基因组特征。与其他禽源星状病毒序列相比，该基因组的独特特征和潜在差异包括鉴定出位于 ORF1b 终止密码子之前的 ORF2 起始密码子附近的修饰 sgRNA 序列。此外，MP22-196 的 3'UTR 比其他禽源星状病毒短。本研究扩展了对 Avastrovirus 4 分支的认识。
