Isolation and preliminary characterization of mutants of western equine encephalomyelitis virus with altered virulence in chickens.
Isolation and preliminary characterization of mutants of western equine encephalomyelitis virus with altered virulence in chickens.
复制标题
鸡毒力改变的西方马脑脊髓炎病毒突变体的分离和初步表征。
DOI：
10.1002/jmv.1890160104
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发表时间：
1985
影响因子：
12.7
通讯作者：
Hardy,J
中科院分区：
文献类型：
--
作者：
Fraizer,G;Main,O;Hardy,J
在用5-氮杂胞苷或亚硝基胍诱变或在蚊子细胞培养物中未稀释传代后，从高毒力田间分离株（BFS-1703）中获得西部马脑脊髓炎病毒（WEEV）的一个小空斑（sp）和四个温度敏感型（ts）突变体。通过6小时泄漏率和空斑效率（EOP）分析确定，3种ts突变体（158、214和260）表达稳定的ts表型。ts突变体214在非允许温度下生长的后代缺乏血凝素活性。sp突变体（148）对新孵化的鸡（12小时龄时感染）的毒力与野生型病毒（WTV）一样高，而ts突变体对该宿主的毒力减弱。衰减与感染后24小时血样中较低的病毒血症滴度相关。WTV和那些能够感染21日龄鸡的突变体产生非致死性感染，但ts 158的生长在这种高温非允许宿主中明显受到限制。除了ts 158外，所有ts突变体在新孵化的鸡和维持在42°C的鸭胚胎细胞培养物（DECC）中生长24小时后失去了它们的ts表型。
A small plaque (sp) and four temperature‐sensitive (ts) mutants of western equine encephalomyelitis virus (WEEV) were obtained from a highly virulent field isolate (BFS‐1703) after mutagenesis with 5‐azacytidine or nitrosoguanidine or following undiluted passage in mosquito cell culture. Three ts mutants (158, 214, and 260) expressed stable ts phenotypes as determined both by six‐hour leak yield and efficiency of plaquing (EOP) analyses. Progeny of ts mutant 214 grown at the nonpermissive temperature lacked hemagglutinin activity. The sp mutant (148) was as highly virulent as the wild‐type virus (WTV) for newly hatched chickens (infected when 12 hours old), whereas the ts mutants were attenuated in their virulence for this host. Attentuation was correlated with lower viremia titers in 24‐hour postinfection blood samples. The WTV and those mutants able to infect 21‐day‐old chickens produced nonlethal infections but the growth of ts 158 was apparently restricted in this high‐temperature nonpermissive host. All ts mutants except ts 158 lost their ts phenotype after growth for 24 hours in newly hatched chickens and in duck embryonic cell culture (DECC) maintained at 42°C.