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

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

分析1株2004年从广东省分离获得的HSN1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／Chi—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 one strain of Avian influenza virus （AIV） HSN1 named A/duck/GuangdongJiedong/23/2004 （ HSN1 ） （ 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.