鸭源H5N1亚型禽流感病毒分离株的致病性及表面蛋白基因序列分析

分析1株2004年从广东省分离获得的H5N1型禽流感病毒株A/Duck/GuangdongJiedong/23/2004对SPF鸡和鸭的致病性,并对其血凝素(HA)基因和神经氨酸酶(NA)基因的序列进行测定,与GenBank中收录的其他序列进行比较。结果,此分离株对SPF鸡和鸭均具有高致病性,且致死率达100%。HA基因与SCK/ST/475/04的同源率最高,而NA基因与Ck/GD/178/04同源率最高。进化分析结果表明,此毒珠与DK/Ch i-na/E319-2/03的HA、NA亲缘关系较近,推测它们来源于同一祖代毒株。推导的HA基因氨基酸裂解位点为-RRRKK-,具有典型高致病性禽流感的特征序列;NA基因颈部49~68位20个氨基酸缺失是近年来H5N1亚型优势流行株共同的遗传标志。

Pathogenicity of avian influenza viruse H5N1 from duck and sequence analysis of spike protein genes

Pathogenicity of one strain of Avian influenza virus(AIV) H5N1 named A/duck/GuangdongJiedong/23/2004(H5N1)(DK/GDJD/23/04),was analyzed.The hemagglutin(HA) and neuraminidase(NA) genes had been sequenced and compared with those in GenBank.The results showed DK/GDJD/23/04 had high pathogenicity to the SPF chicken and duck,causing 100% mortality.DK/GDJD/23/04 shared high identity with SCK/ST/475/04 in HA gene and shared high identity with Ck/GD/178/04 in NA gene.Phylogenetic analysis revealed that both HA and NA genes of DK/GDJD/23/04 had genetically close relationship with DK/China/E319-2/03,which suggested that they came from the same origin.The sequence of cleavage site between HA1 and HA2 consisted of-RRRKK-,which was the sequence of the high pathogenic AIV,and a 20-amino acid delection in NA stalk(residues49-68),was the genetic marker of the majority strains in recent years.