Isolation and Characterization of Equine Influenza Viruses (H3N8) from China, 2010~2011
Gang Lu1,§, Jie Chen2,§,
Wei Guo1,§, Ting Qi1,§, Liping Zhao1,
Hongmei Li1, Yuanyuan Ji1, Zheng Wang1,
Cuiyun Liu1, Shihua Zhao1 and Wenhua Xiang1,*
1Division of Livestock
Infectious Diseases, State Key Laboratory of Veterinary
Biotechnology, Harbin Veterinary Research Institute, Chinese Academy
of Agricultural Sciences, Harbin 150001, PRC; 2The 3rd
Hospital Affiliated to Harbin Medical University, Harbin 150001,
People’s Republic of China
Abstract
Two
equine influenza virus (EIV) strains were isolated during two restricted
outbreaks from Heilongjiang Province, China in 2010 and 2011. Phylogenetic analysis of HA1 (haemagglutinin1) gene revealed that the isolates belonged to Florida 2 sublineage of
American lineage. Further analysis of the putative antigenic sites located in
HA1 subunit protein revealed each isolate had a unique amino acid change.
Analysis of antigenic sites between Chinese EIV and vaccine strains indicated
equine influenza (EI) vaccines containing Richmond/1/07-like antigen seemed to
have an optimum effect in
China. Meanwhile, the Ohio/03 vaccine strain
contained in updated ProteqFlu had the most closely genetically relationship
with recent EIV isolates in China. China has not
its own commercially available EI vaccine and most horses are still
unvaccinated. Therefore, to monitor antigenic variation of circulating EIVs and
give considerable suggestions on selection of vaccine candidate plays an
important role in preventing and controlling EIV in China.