1株H1亚型水禽流感病毒分离株的致病特性和表面膜蛋白基因的序列分析

采用常规血清学试验和特异性RT-PCR方法,对我国华东地区家养水禽流感病毒进行了长达4年的跟踪监测,分离到多株H1亚型禽流感病毒,并对其中的1株A/Duck/Yangzhou/163/2003(简称Dk/YZ/163/03)的血凝素基因进行了序列测定,并与GenBank中收录的其他序列进行了比较。结果发现,Dk/YZ/163/03的血凝素基因(HA)与禽流感日本分离株A/Japan/91(H1)的同源性最高;而神经氨酸酶基因(NA)与Mallard dk/A1b/35/1976(H1N1)同源性最高;其推导的氨基酸剪切位点序列为P-S-I-Q-S-R,是典型低致病性禽流感病毒的特征序列,这与该毒株对SPF鸡和BALB/c小鼠的低致病特性相吻合。

Phylogenetic analysis of the surface glycoprotein genes of a water fowl origin influenza virus isolate A/Duck/Yangzhou/163/2003 (H1N1) and pathogenic for SPF chickens and BALB/c mice

Several H1 subtype avian A influenza viruses were isolated from aquatic birds in some live bird markets when we surveyed the ecology of the influenza in East China for more than four years and identified by specific RT-PCR.In this paper,the hemagglutinin(HA) gene and neuraminidase(NA) of one representative virus named A/Duck/Yangzhou/163/2003(Dk/YZ/163/03) had been sequenced and Dk/YZ/163/03 pathogenic for SPF chickens and BALB/c mice had been determined.The results showed that the HA nucleotide sequence of Dk/YZ/163/03 have a high identity with A/Japan/91(H1);Phylogenetic analysis of the NA genes of Dk/YZ/163/03 revealed that the NA gene of Dk/YZ/63/03 had genetically close relationships with that of Mallard dk/A1b/35/1976(H1N1),the sequence of cleavage site between HA1 and HA2 consists of P-S-I-Q-S-R as is the case with most other hemagglutinins exhibiting low susceptibility to proteolytic activation.;none of the chickens and mice inoculated with Dk/YZ/163/03 displayed any obvious signs of clinical disease.