การศึกษาคุณสมบัติทางด้านโมเลกุลของเชื้อไข้หวัดนก H5N1 subtype ที่แยกได้ในประเทศไทย

การศึกษาทางชีวโมเลกุลของเชื้อไข้หวัดนก

Highly pathogenic avian influenza A H5N1 subtype emerged in Thailand during 2006 to early 2008. All the viral genes were of avian influenza origin, which indicates the absence of reassortment with human influenza viruses. The phylogenetic analysis of HA gene demonstrated that all of the studied viruses belonged to Clade1 (A/ck/Phichit//NIAH1/06,A/ck/Angthong/NIAH101204/07, A/ck/Nakhonsawan/NIAH600567/08 and A/ck/Phichit/NIAH600674/08) and Clade 2.3.4 (A/ck/Nakhonphanom/NIAH113718/06, A/ck/Nongkhai/NIAH400802/07 and A/c/kMukdahan/NIAH40390/07). Four isolates (A/ck/Nakhonsawan/NIAH600567/08, A/ck/Phichit/NIAH600674/08, A/ck/Angthong/NIAH101204/07, A/ck/Phichit/NIAH1/06) may be resistant to the amantatidine drugs but sensitive to neuraminidase inhibitors(Oseltamivir carboxylate). The A/ck/Nakhonphanom/NIAH113718/06, A/ck/Nongkhai/NIAH400802/07and A/ck/Mukdahan/NIAH40390/07 isolates showed an evidence of the antigenic shift of RNA polymerase acid (PA) gene and lack of one Lys(K) of the polybasic cleavage site (PLRERRRK_R/GLF) of the haemagglutinin (HA) gene, but in all isolates, there was deletion of 20 amino acid at the position 49 - 68 of neuranimidase (NA) gene and 5 amino acid at the position 80 - 84 of nonstructure (NS1) gene.