# The phylogenetic, pathogenicity and transmission capacity analysis of one H9N2 strain

## TL;DR

This study analyzes an H9N2 avian influenza strain, revealing its genetic lineage and transmission potential to mammals.

## Contribution

The study identifies the phylogenetic lineage and transmission capacity of a newly isolated H9N2 strain.

## Key findings

- The H9N2 strain binds to α-2,6 sialic acid receptors, indicating potential mammalian infection.
- The strain shows low pathogenicity in mice and can transmit via contact and aerosol in guinea pigs.
- The strain's genetic segments belong to distinct lineages within the Eurasian lineage.

## Abstract

Avian influenza is an acute and highly contagious infectious disease that can infect multiple hosts. The low pathogenic avian influenza virus (LP-AIV), represented by the H9-subtype can cause a decrease in egg production and immunosuppression, lead to respiratory diseases and other diseases, reduce poultry production efficiency, and seriously affect the sustainable development of the poultry industry. In this study, one strain of H9-subtype AIV was isolated, purified, and named A/Hebei/723/2019 (H9N2). Phylogenetic analysis indicated that the HA, NA and M genes of the isolated strain belonged to the Y280-like lineage in the Eurasian lineage. The PA, NP and NS genes belong to the SH/F/98-like lineage. The PB1 gene belongs to the Y439-like lineage. The PB2 gene belongs to the G1-like lineage. Moreover, this strain binds exclusively to the α-2,6 sialic acid receptor, exhibits low pathogenicity to mice, and can be transmitted directly through contact and aerosol transmission among guinea pigs. It has a potential risk of infecting mammals and provides reference value for the subsequent formulation of measures for disease prevention and control.