伪狂犬病病毒弱毒株LY株的分离鉴定

从辽阳某猪场的10日龄仔猪中分离到1株病毒,经纯化后测得其毒价为107.29TCID50/mL.细胞中和试验表明,该病毒能被猪伪狂犬病病毒标准阳性血清所中和.电镜下可见到典型的疱疹病毒粒子,具有囊膜及外周纤突.所分离的病毒对氯仿、胰蛋白酶、乙醚敏感,在pH5.0～9.0下稳定,56℃ 30 min可以灭活.应用特异性引物,通过PCR能扩增出伪狂犬病病毒1 240 bp的gD基因.分离病毒对3日龄乳鼠有一定的致病力,但对家兔、3～5日龄仔猪及妊娠母猪都有很高的安全性.用不同剂量的病毒培养液肌肉注射于3～5日龄仔猪,14 d后用105.7TCID50伪狂犬病病毒强毒攻击,所有试验仔猪均可得到有效保护.用分离毒免疫母猪,其后代可获高滴度的母源抗体,15日龄的仔猪能抵抗105.7TCID50强毒的攻击.试验的结果初步说明,所分离的病毒为伪狂犬病病毒(命名为PRV LY株),并可能是一株弱毒株,而且具有很好的免疫保护作用.

Isolation and identification of an attenuated strain of pseudorabies virus

A strain pseudorabies virus named LY strain was isolated from pigs in Liaoyang.The virus isolate was purified by plaque technique on CEF monolayer with the titer of 10 7 29 TCID 50 /mL.Virus neutralization(VN) test showed that the isolate could be neutralized by PRV positive serum.Envelope and peplomers were observed on the surface of the virus under electron microscope.With the special primer,the gD gene about 1 240 bp was obtained by PCR.The virus isolate was pathogenic to 3 days mice and safe to rabbits and neonatal pigs.The neonatal pigs inoculated with different doses (10 0,10 -1 ,10 -2 mL) of the isolate showed no clinical signs when challenged with virulents train of PRV after a 14 day vaccination.Weaned pigs acquired high titer maternal antibodies from vaccinated sows and could be protected against PRV infection.Antibody to the isolate was detected from the vaccinated pigs.According to the above results,it was suggested that the virus isolate might be an attenuated PRV virus with good protection against virulent strain of PRV.