Division of Vector-borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado 80521, USA.
Am J Trop Med Hyg. 2011 Oct;85(4):758-67. doi: 10.4269/ajtmh.2011.10-0439.
A West Nile virus (WNV) isolate from Mexico (TM171-03) and BIRD1153, a unique genotype from Texas, have exhibited reduced murine neuroinvasive phenotypes. To determine if murine neuroinvasive capacity equates to avian virulence potential, American crow (Corvus brachyrhynchos) and house sparrows (Passer domesticus) were experimentally inoculated with representative murine neuroinvasive/non-neuroinvasive strains. In both avian species, a plaque variant from Mexico that was E-glycosylation competent produced higher viremias than an E-glycosylation-incompetent variant, indicating the potential importance of E-glycosylation for avian replication. The murine non-neuroinvasive BIRD1153 strain was significantly attenuated in American crows but not house sparrows when compared with the murine neuroinvasive Texas strain. Despite the loss of murine neuroinvasive properties of nonglycosylated variants from Mexico, our data indicate avian replication potential of these strains and that unique WNV virulence characteristics exist between murine and avian models. The implications of reduced avian replication of variants from Mexico for restricted WNV transmission in Latin America is discussed.
一株来自墨西哥的西尼罗河病毒（WNV）分离株（TM171-03）和一株来自德克萨斯州的独特基因型 BIRD1153，表现出降低的小鼠神经侵袭表型。为了确定小鼠神经侵袭能力是否等同于禽类致病潜力，用具有代表性的小鼠神经侵袭/非神经侵袭株对美洲乌鸦（Corvus brachyrhynchos）和家麻雀（Passer domesticus）进行了实验接种。在这两种禽类中，一种来自墨西哥的能够进行 E 糖基化的斑块变异株产生的病毒血症高于一种 E 糖基化无能的变异株，表明 E 糖基化对禽类复制的潜在重要性。与小鼠神经侵袭性的德克萨斯株相比，当与小鼠非神经侵袭性的 BIRD1153 株相比时，美洲乌鸦中的 BIRD1153 株显著减弱。尽管来自墨西哥的非糖基化变异株失去了小鼠神经侵袭性，但我们的数据表明这些株具有禽类复制潜力，并且在小鼠和禽类模型之间存在独特的 WNV 毒力特征。讨论了墨西哥变异株禽类复制减少对拉丁美洲有限的 WNV 传播的影响。
