Isolation and Preliminary Identification of H9 Subtype Influenza A Viruse

2011 two strains(FZ-04 and FZ-11)were isolated respectively from two broiler farms in Fujian.Hemagglutination test results showed that the isolated allantoic fluid can induce 1% chicken erythrocytes agglutination.Hemagglutination inhibition test results showed that the isolates allantoic fluids were only inhibited by avian influenza virus subtype H9 standard serum specificly.Specified and conserved M(Matrix)gene and HA(Hemagglutinin)gene of H9 subtype were amplified by RT-PCR with the segment lengths of 229bp and 732bp respectively.The results indicated that the isolated strains were H9 subtype of influenza A virus.The phylogenetic analysis of HA genes showed that isolates and representative strains CK/FJ/G9/09 have a closest relationship,belonging to the major sublineage CK/BJ/1/94 in China.