对2013年从健康野生鹭科候鸟中分离的新城疫病毒(Newcastle disease virus,NDV)蚀斑纯化后,选择5株病毒进行了生物学鉴定和遗传进化分析。致病指数和脑内接种指数测定结果显示5个分离株均为弱毒株;F蛋白裂解位点处氨基酸序列均为112ERQERL117,具有典型的弱毒株特征。交叉HI试验结果发现ClassⅠ分离株与La Sota的HI抗原同源性为0.56~0.57,与ClassⅡ强毒株的HI抗原同源性为0.44~0.51;遗传进化分析发现5个NDV毒株与目前流行的强毒株遗传关系较远,均属于ClassⅠ3c亚型,表明健康鹭携带I类新城疫病毒,在迁飞的过程可能传播给家养水禽,对其构成潜在威胁,提示加强野鸟NDV的监控及流行病学研究具有紧迫性和重要性。
In order to understand the biological characteristics and genetic evolution of five class Ⅰ Newcastle disease viruses(NDV) isolated from ardeid wildbirds, these viruses were inoculated into one-day-old chicks. Results indicated that these five NDV isolates were all lentogenic according to the mean death time(MDT) and intracerebral pathogenicity index(ICPI). Cross HI test showed that HI homology was 0.56~0.57 between these isolates and La Sota and 0.44~0.51 between these isolates and Class Ⅱ isolates. Phylogenetic analysis of these isolates based on 47-470 bp of F genes revealed that all isolates were clustered into Class I group 3c clade. Class I NDV carried by healthy wild water fowls might have spread to domestic waterfowls through migration, posing a potential threat to domestic poultry. The results from the present study suggested the urgency and importance of strengthening the epidemiological studies of NDV in wild birds.