鸡新城疫强毒株的分离与鉴定

从山东某鸡场的产蛋下降而无其他典型ND症状的高抗体蛋鸡群中分离到一株病毒。经过试验鉴定．该分离株具有血凝性，且可被ND标准阳性血清所抑制和中和，不能被AI（H5亚型与H9亚型）标准阳性血清抑制；该病毒的最小致死量病毒致死鸡胚的平均时间（MDT）为50．4，1日龄SPF鸡脑内接种分离病毒致病指数（ICPI）为1．85，6周龄SPF鸡静脉接种致病指数（WPI）为2．42，回归试验鸡出现了新城疫症状和病变，该病毒株确定为新城疫病毒强毒型，并暂命名为ShD-dzh04。

The Isolation and Identification of Avian NDV

One virus isolated from Shandong current outbreak ND chicken farms that only showed egg dropping and without any typical symptom was studied.The results of idenfication showed that the ioslate is able to agglutinate chicken red blood cells,which can be inhibited and neutralized by avian Newcastle disease virus (NDV) standard antiserum,but can not be inhibited by avian influenza virus (AIV) standard antiserum (H5 and H9 subtype) and EDS- 76 standard antiserum. Its MDT,ICPI and IVPI are 50.4,1.85 and 2.42 respectively. The ND pathological changes and symptoms also appeared in the challenged chickens. The results disclosed that the isolate is virulent strain of Newcastle disease virus.The isolate was named as ShD- dzh04.