Infectivity variation and genetic diversity among strains of Western equine encephalitis virus
Infectivity variation and genetic diversity among strains of Western equine encephalitis virus
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DOI：
10.1099/vir.0.81815-0
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发表时间：
2006-08-01
影响因子：
3.8
通讯作者：
Wong, Jonathan P.
中科院分区：
文献类型：
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作者：
Nagata, Les P.;Hu, Wei-Gang;Wong, Jonathan P.
对西方马脑炎病毒 (WEEV) 的八个毒株的感染性和结构蛋白遗传多样性进行比较，以在分子水平上研究 WEEV 毒力。在成年 BALB/c 小鼠中建立了 WEEV 致死性鼻内感染模型。在该模型中，所检查的所有八种菌株对成年小鼠均 100% 致死，但它们的死亡时间差异很大。根据死亡时间，这8株菌株可分为两种致病型：高毒力致病型，包括California、Fleming和McMillan菌株；低毒力致病型，包括菌株CBA87、Mn548、B11、Mn520和71V-1658。为了分析结构蛋白基因的遗传多样性，对这八个菌株的 26S RNA 进行了克隆和测序，发现其具有 > 96% 的核苷酸和氨基酸同一性。聚类图将八个 WEEV 毒株分为两种与致病型分组完全匹配的基因型，表明感染性的变化可归因于这八个毒株中结构蛋白的遗传多样性。此外，还确定了两组之间某些位置的潜在氨基酸差异，表明这些氨基酸变化导致了观察到的毒力差异。
Variation in infectivity and genetic diversity in the structural proteins were compared among eight strains of Western equine encephalitis virus (WEEV) to investigate WEEV virulence at the molecular level. A lethal intranasal infectivity model of WEEV was developed in adult BALB/c mice. All eight strains examined were 100 % lethal to adult mice in this model, but they varied considerably in the time to death. Based on the time to death, the eight strains could be classified into two pathotypes: a high-virulence pathotype, consisting of strains California, Fleming and McMillan, and a low-virulence pathotype, comprising strains CBA87, Mn548, B11, Mn520 and 71V-1658. To analyse genetic diversity in the structural protein genes, 26S RNAs from these eight strains were cloned and sequenced and found to have > 96 % nucleotide and amino acid identity. A cluster diagram divided the eight WEEV strains into two genotypes that matched the pathotype grouping exactly, suggesting that variation in infectivity can be attributed to genetic diversity in the structural proteins among these eight strains. Furthermore, potential amino acid differences in some positions between the two groups were identified, suggesting that these amino acid variations contributed to the observed differences in virulence.