Generation of velogenic Newcastle disease viruses from a nonpathogenic waterfowl isolate by passaging in chickens
Generation of velogenic Newcastle disease viruses from a nonpathogenic waterfowl isolate by passaging in chickens
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DOI：
10.1006/viro.2002.1539
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发表时间：
2002-09-30
期刊：
影响因子：
3.7
通讯作者：
Ito, T
中科院分区：
文献类型：
--
作者：
Shengqing, Y;Kishida, N;Ito, T
一种良性新城疫病毒（NDV）最近在家鸡中复制时变得具有高毒力。目前尚不清楚野生水禽中传播的新城疫病毒是否也有可能对鸡产生高致病性（强毒）。为了通过实验证明从非致病性水禽分离株中产生强毒新城疫病毒，我们将无毒力的鹅分离株在鸡中进行传代。通过气囊接种连续传代 9 次，然后在鸡脑中传代 5 次，该病毒在鸡中变得具有高毒力，死亡率为 100%，并在致病性测试中表现出典型的猛烈特性。融合蛋白切割位点的序列分析表明，原始分离物含有典型的无毒型序列 E-R-Q-E-R/L，在鸡中重复传代期间逐渐发展为典型的毒力型 K-R-Q-K-R/F。这些结果表明，野生水禽中存在的无毒病毒具有共有的无毒型序列，在传播到鸡群并在鸡群中传播后有可能产生烈性病毒。研究结果还表明，鸡提供了一种从无毒背景中选择强毒病毒的机制。 (C) 2002 年爱思唯尔科学（美国）。
A benign Newcastle disease virus (NDV) recently became highly virulent during replication in domestic chickens. It is still unclear whether NDVs circulating among wild waterfowl also have the potential to become highly pathogenic (velogenic) in chickens. To demonstrate experimentally the generation of velogenic NDV from a nonpathogenic waterfowl isolate, we passaged an avirulent goose isolate in chickens. After nine consecutive passages by air-sac inoculation, followed by five passages in chick brain, the virus became highly virulent in chickens, producing a 100% mortality rate, and demonstrating typical velogenic properties in pathogenicity tests. Sequence analysis at the fusion protein cleavage site showed that the original isolate contained the typical avirulent type sequence, E-R-Q-E-R/L, which progressed incrementally to a typical virulent type, K-R-Q-K-R/F, during repeated passage in chickens. These results demonstrate that avirulent viruses, maintained in wild waterfowl in nature and bearing the consensus avirulent type sequence, have the potential to become velogenic after transmission to and circulation in chicken populations. The results also suggest that chickens provide a mechanism for the selection of virulent viruses from an avirulent background. (C) 2002 Elsevier Science (USA).