Abstract:

In order to investigate the molecular mechanism affecting the airborne transmission for H9N2 avian influenza virus (AIV), one isolates from Shandong province (SD01) was chose as research subject. The character of its complete nucleotide sequences and phylogenetic tree were analyzed. One recombinant AIV (R01/NASS), NA gene from Guangdong isolate (SS94) without airborne transmissibility and other seven genes from SD01 with this ability, was generated by reverse genetics and its transmissibility was determined in chickens. The results showed that M, NS, NP and HA genes had the highest homology with HK/G9/97, NA, PB1 and PB2 genes had highest homology with HK/Y280/97, and PA gene with SH/F/98. Transmission experiment indicated that the recombinant AIV could transmit by direct contact, but not by aerosol. These results demonstrated that the replacement of NA gene made SD01 virus lost its airborne transmissibility. The results would be useful for further studies on the key amino acids of NA protein, which may relate to the airborne transmission of H9N2 AIVs.