GENETIC VARIATION OF ST LOUIS ENCEPHALITIS VIRUS IN CA

这份新的R03研究提案涉及名为Expanded的PA-96-048 圣路易斯脑炎(SLE)病毒新发疾病研究进展 自20世纪30年代以来一直活跃在加州，S可能会重新- 在未来会成为一个严重的健康威胁。这种病毒构成了一种 随着湿地的恢复，住房对加州的威胁越来越大 毗邻的发展项目及康乐用地，以及 杀虫剂的使用越来越受到限制。在蚊子肆虐的季节 是活跃的，SLE病毒被维持在涉及野生动物的地方性循环中 鸟类和蚊子媒介。我们建议维持SLE病毒 通过坚持在加州度过不利的季节和年份 周期性出现新基因型和/或周期性的地方病疫源地 从其他疫区引进。建议的目标是 研究是使用分子遗传学方法来解决 SLE病毒的复发和扩散。类群的系统发育分析 中国人系统性红斑狼疮病毒分离株核苷酸和氨基酸序列 并与来自其他地方的病毒分离株进行了比较 包括密西西比河流域在内的美国部分地区， 东海岸和德克萨斯州，加勒比海，巴拿马，以及南部和中部 美国将在一段较长的时间内允许确定 SLE病毒基因改变的速度，是否有 恒定的分子变化或加速变化的插曲，以及 该病毒在不同的地理区域之间传播。建议 研究验证了假设，在给定的SLE病毒分离物 随着时间的推移，地理区域的基因变化很小，这表明 它们在这些地区持续存在，但新的基因型别是周期性的 被引入的或出现的，与先前存在的 基因分型。这项研究可能有助于解释出现的一种方式 来自温带气候地方病疫源地的黄病毒。

This new R03 research proposal addresses PA-96-048 entitled Expanded Research on Emerging Diseases St. Louis encephalitis (SLE) virus has been consistently active in California since the 1930's and may re- emerge in the future as a serious health threat. This virus poses an increasing threat to California as wetlands are restored, housing developments and recreational sites located adjacent to them, and the use of pesticides increasingly restricted. In seasons when mosquitoes are active, SLE virus is maintained in enzootic cycle involving wild birds and mosquito vectors. We proposed that SLE virus is maintained through adverse seasons and years in California by persistence in enzootic foci with periodic emergence of new genotypes and/or periodic introduction from other enzootic areas. The objective of the proposed research is to use a molecular genetic approach to address the recrudescence and dispersal of SLE virus. Phylogenetic analysis of nucleotide and amino acid sequences of SLE viral isolates from throughout California and a comparison with viral isolates from other sections of the United States including the Mississippi River Basin, East Coast and Texas, and the Caribbean, Panama, and South and Central America, over an extended period of time, will allow determination of the rate at which the SLE viral genotype is changing, whether there is constant molecular change or episodes of accelerated change, and whether the virus is being carried between discrete geographic areas. Proposed research tests the hypothesis that isolates of SLE virus in given geographic areas show little genetic change over time, suggesting that they persist in those areas, but new genotypes are periodically introduced or emerge which circulate with the previously existing genotype. This study may help explain one means of emergence of flaviviruses from enzootic foci in temperate climates.