伪狂犬病毒弱毒株若干生物学特性
Biological Characteristics of Pseudorabies Virus(PRV)Vaccine Strain
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摘要: 报道了应用本所1962年分离的伪狂犬病毒闽A株强毒为种毒(简称PRVFA).该病毒株已在乳地鼠肾和乳兔肾原代细胞上传500代后,对多种家畜仍保持原来的毒力。后采用蚀斑克隆,筛选直径小于2mm的小斑,并结合低温诱变,选育出伪狂犬病毒弱毒株(简称PRVFB).在兔肾细胞上传代第180代病毒滴度稳定为107~108TCID50,以(1~2)×104TCID50/头剂量感染,对2kg重的家兔仍有35%发病死亡或麻痹和奇痒症状,其中有极少数耐过康复;对乳猪已无致病性;对其它家畜的奇痒症诱发力消失;用家兔和乳猪盲传未发现返强;接种动物同居感染未发现水平传播;制成冻干弱毒疫苗的病毒最低滴度为lgTCID50=5.0;接种多种家畜安全有效。Abstract: The Prv vaccine(PRVFB)has been selected from PRVFA isolated from Fujian in rabbit embryo kidney cells by plague technique with low temperature mutagenesis. The TCID50 was about 107 ~108.35% of the 2kg-weight rabbits infected with 2×104 appeared strong itching, para-lytic symptom of death, few of which were tolerant.But the vaccine was umpathogenic to pig and the passages on pigs and rabbits. The tested animals living together could not be found to infect each other.The lowest liter was 105.5 TCIDso of the lyophilized vaccine prepared from the chicken embryo fibroblast cells and its immune period could be about one year.