Genomic and phylogenetic characterization of novel, recombinant H5N2 avian influenza virus strains isolated from vaccinated chickens with clinical symptoms in China.

Dihai Huang,Leyi Wang,Zhuoming Qin,Wei Zhang,Weishan Chang,Youling Wang,Fang Meng,Huaiying Xu,Xiaodan Sheng

doi:10.3390/v7030887

Abstract

Infection of poultry with diverse lineages of H5N2 avian influenza viruses has been documented for over three decades in different parts of the world, with limited outbreaks caused by this highly pathogenic avian influenza virus. In the present study, three avian H5N2 influenza viruses, A/chicken/Shijiazhuang/1209/2013, A/chicken/Chiping/0321/2014, and A/chicken/Laiwu/0313/2014, were isolated from chickens with clinical symptoms of avian influenza. Complete genomic and phylogenetic analyses demonstrated that all three isolates are novel recombinant viruses with hemagglutinin (HA) and matrix (M) genes derived from H5N1, and remaining genes derived from H9N2-like viruses. The HA cleavage motif in all three strains (PQIEGRRRKR/GL) is characteristic of a highly pathogenic avian influenza virus strain. These results indicate the occurrence of H5N2 recombination and highlight the importance of continued surveillance of the H5N2 subtype virus and reformulation of vaccine strains.

Highlights

Infection of poultry with diverse lineages of H5N2 avian influenza viruses has been documented for over three decades [1]
Three H5N2 avian influenza virus strains were isolated from chickens with clinical symptoms of AIV from each farm
Three H5N2 influenza virus strains isolated from chickens were identified as novel reassortants with a highly pathogenic viral genotype

Summary

Introduction

Infection of poultry with diverse lineages of H5N2 avian influenza viruses has been documented for over three decades [1]. Less than one year after that outbreak the virus was found to have mutated into a highly pathogenic avian influenza (HPAI) H5N2 strain after adaptation in birds and causing high mortality in poultry [2]. Since both LPAI and HPAI H5N2 strains have been identified frequently among domestic and wild bird populations worldwide [3,4,5,6,7,8,9,10,11]. Reassortant H5N2 viruses detected in domestic poultry belong to H5 clades 2.3.2, 2.3.4 or 7.2, and the represented reassortment events involve genes of different subtypes, including H3, H5, H6 H7, H9, and H11viruses [6,13,14,15,16,17]

Methods

Results

Conclusion