King D J, Seal B S
U.S. Department of Agriculture, Southeast Poultry Research Laboratory, Athens, GA 30605, USA.
Avian Dis. 1998 Jul-Sep;42(3):507-16.
Fifty-seven Newcastle disease virus (NDV) isolates from chickens, turkeys, a rhea, a parrot, and an anhinga were pathotyped and characterized by monoclonal antibody (mAb) inhibition profile, elution rate, and hemagglutinin thermostability. Nucleotide sequence analysis of portions of the fusion protein and matrix protein genes of the parrot isolate was done for comparison with prior sequence analysis of the anhinga isolate and NDV reference strains. Seven of the 43 chicken isolates were recovered from flocks in Canada. The remaining isolates, including 11 from turkeys, were isolated in the United States. All isolates except that of the anhinga were of low virulence by mean death time in embryos, intracerebral pathogenicity index, and/or intravenous pathogenicity index procedures and were classified as lentogens. The anhinga isolate was more virulent than the other strains and was pathotyped as a mesogen. However, nucleotide sequence analysis of the anhinga isolate had revealed a homology with the virulent cormorant isolates of 1992 rather than the classical U.S. mesogens characterized by the Roakin strain. Variability was evident among the lentogenic isolates. Two isolates from turkeys had mAb profiles that differed from B1 and La Sota reference and vaccine strains, and 38% (21/56) of the isolates had more thermostable hemagglutinins than those reference strains. There was no evidence that any of the isolates from poultry were more virulent than the lentogenic pathotype.
对从鸡、火鸡、美洲鸵鸟、鹦鹉和蛇鹈中分离出的57株新城疫病毒（NDV）进行了致病型鉴定，并通过单克隆抗体（mAb）抑制谱、洗脱率和血凝素热稳定性进行了特征分析。对鹦鹉分离株的融合蛋白和基质蛋白基因部分进行了核苷酸序列分析，以便与之前对蛇鹈分离株和NDV参考毒株的序列分析进行比较。43株鸡分离株中的7株是从加拿大的鸡群中分离得到的。其余分离株，包括11株火鸡分离株，是在美国分离得到的。除蛇鹈分离株外，所有分离株通过鸡胚平均死亡时间、脑内致病指数和/或静脉致病指数检测均为低毒力，并被归类为缓发型毒株。蛇鹈分离株比其他毒株毒力更强，被鉴定为中发型毒株。然而，蛇鹈分离株的核苷酸序列分析显示，它与1992年的强毒鸬鹚分离株具有同源性，而不是与以Roakin毒株为特征的经典美国中发型毒株具有同源性。缓发型毒株之间存在明显的变异性。两株火鸡分离株的mAb谱与B1和La Sota参考毒株及疫苗株不同，38%（21/56）的分离株血凝素的热稳定性高于那些参考毒株。没有证据表明任何家禽分离株的毒力比缓发型致病型更强。
