【摘要】 试验旨在测定一株从番鸭中分离获得的禽Ⅰ型副黏病毒(GSFY株)的生物学特性和遗传特性,并将其制成油乳剂灭活疫苗,进行番鸭免疫保护试验。结果显示,GSFY株的平均致死时间(mean death time,MDT)为71h,脑内接种致病指数(intracerebral pathogenicity index,ICPI)为1.75,静脉接种致病指数(intravenous pathogenicity index,IVPI)为2.49;GSFY株F基因核苷酸序列同源性分析显示,其与鸡源Chicken/China/Guangxi 9/2003株同源性最高,为97.1%,且二者均处于基因Ⅶ型分支,综合以上结果确定其为禽Ⅰ型副黏病毒基因Ⅶ型强毒株。免疫保护试验结果显示,疫苗进行3次免疫后对番鸭有良好的免疫保护效果,3次免疫后第7天抗体效价平均值达到6log2,第21天抗体效价平均值达到8log2,用GSFY毒株攻击免疫番鸭,当抗体滴度>5log2时,保护率达100%。本研究结果为生产实践制订鸭预防禽Ⅰ型副黏病毒病的免疫程序提供参考。更多还原

【Abstract】 In this study,the biological and genetic characterization of a paramyxovirus type Ⅰstrain(GSFY strain)which was obtained from Muscovy duck were determined.Afterward,GSFY strain was developed as an inactivated oil emulsion vaccine.The protective evaluation of this new vaccine candidate was conducted on the Muscovy duck.The results showed that the mean death time(MDT)of chicken embryo,the intracerebral pathogenicity index(ICPI)of 1-day-old chicken and the intravenous pathogenicity index(IVPI)in 6-week-old chicken were 71 h,1.75 and 2.49,respectively.Homologous comparison of Fgene nucleotide sequence showed that the GSFY strain shared 97.1% with Chicken/China/Guangxi 9/2003,which was the highest homology,and they all belonged to typeⅦ.The results suggested that this newly isolated strain was the typeⅦ high virulent paramyxovirus.The immunize protective evaluation results suggested that the mean antibody titer of 7and 21 days after the third immunization were 6log2 and 8log2,respectively.When the immunized duck were attacked with GSFY strain,100% protective rate could be expected when the mean antibody titer was above 5log2.This study provided the basic data for vaccine development of avian typeⅠ paramyxovirus.更多还原