Genetic characterization of an H5N6 avian influenza virus with multiple origins from a chicken in southern China, October 2019

Yong Li,Congying Wang,Qing Cheng,Kaijian Luo,Sheng Yuan,Shujian Huang,Jing Yang,Zheng Tang,Feng Wen,Jinyue Guo

doi:10.1186/s12917-021-02903-z

Yong Li, Congying Wang + Show 8 more

Open Access

https://doi.org/10.1186/s12917-021-02903-z

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Abstract

BackgroundHighly pathogenic avian influenza viruses (HPAIVs) of H5 subtype pose a great threat to the poultry industry and human health. In recent years, H5N6 subtype has rapidly replaced H5N1 as the most predominate HPAIV subtype circulating in domestic poultry in China. In this study, we describe the genetic and phylogenetic characteristics of a prevalent H5N6 strain in Guangdong, China.ResultsNucleotide sequencing identified a H5N6 subtype HPAIV, designated as A/chicken/Dongguan/1101/2019 (DG/19), with a multibasic cleavage site in the hemagglutinin (HA). Phylogenetic analysis revealed DG/19 was a reassortant of H5N1, H5N2, H5N8, and H6N6 subtypes of avian influenza viruses. A number of mammalian adaptive markers such as D36N in the HA were identified.ConclusionsOur results showed that HPAIV H5N6 strains still emerge in well-managed groups of chicken farms. Considering the increasing prevalence of H5N6 HPAIV, and the fact that H5N6 HPAIVs are well adapted to migratory birds, an enhanced surveillance for the East Asian-Australasian flyway should be undertaken to prevent potential threats to the poultry industry and human health.

Highlights

Pathogenic avian influenza viruses (HPAIVs) of H5 subtype pose a great threat to the poultry industry and human health
Avian influenza viruses (AIVs), AIVs are classified into highly pathogenic avian influenza viruses (HPAIVs) and low pathogenic avian influenza viruses (LPAIVs) [3]
The results revealed that the AIV in this study belongs to a H5N6 subtype, which was designated as A/ chicken/Dongguan/1101/2019 (H5N6)(DG/19)

Summary

Introduction

Pathogenic avian influenza viruses (HPAIVs) of H5 subtype pose a great threat to the poultry industry and human health. H5N6 subtype has rapidly replaced H5N1 as the most predominate HPAIV subtype circulating in domestic poultry in China. Avian influenza viruses (AIVs) are a group of enveloped viruses characterized with an eight-segmented, singlestranded, negative-sense RNA genome [1]. HPAIVs, including subtypes of H5 and H7, which code for a furin-sensitive multibasic cleavage site (−RRKKR-) in the HA [4, 5], are capable of inducing systemic infections in multiple tissues and causing dramatic economic losses in the poultry industry. A year later, the first human clinical respiratory case of H5N1 was reported in Hong Kong, China [6, 7]. The H5N1 virus has spread across to spread to Southeast Asia, the Middle

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