BORRELIA EVOLUTION AND POPULATION STRUCTURE

拟议的项目旨在深入了解疏螺旋体病原体与其各自的人畜共患脊椎动物宿主和节肢动物媒介之间的相互作用和联系。为了充分描述伯氏杆菌自然种群的结构，有必要从其组织的不同水平上对分离物进行采样，以确定决定伯氏杆菌分离物之间分布和互换性的时间、地理和宿主环境因素。沿海岛屿的使用满足了这种采样的地理要求，沿海岛屿因其独特的品质而被选中，使其成为追踪新出现疾病生态动态的理想自然实验室。这两个地点的时间抽样既是纵向抽样(研究期间每两年对每个岛屿抽样一次)，也是以不重叠的年度周期对扁虱群进行横截面抽样。由于疏螺旋体分离株是直接从其宿主收集的，因此可以直接检测宿主环境之间的关系。将确定来自每个岛屿地点(和每个时间点)的所有小鼠、扁虱和疏螺旋体分离株的多位点基因类型，从而为评估它们各自的种群结构和这些物种之间的相互作用提供丰富的资源。

The proposed project is designed to gain insight to the interactions and associations between Borrelia pathogens and their respective zoonotic vertebrate reservoirs and arthropod vectors. To fully characterize the structure of natural populations of B. burgdorferi, it is necessary to sample isolates from the various levels of its organization to determine the temporal, geographic, and host environmental factors which determine the distribution and exchangeability among B. burgdorferi isolates. Thes geographic requirements of this sampling are met by the use of coastal islands, which have been chosen for the unique qualities that make them ideal natural laboratories for tracking the ecological dynamics of emerging disease. The temporal sampling of these two sites is accomplished both longitudinally (by sampling each islands bi- annually for each year of the study), and by cross-sectional sampling of the tick cohorts in non-overlapping annual cycle. The relationship between the host environments can be tested directly, since the Borrelia isolates are collected directly from their hostsj. The multi-locus genotypes of all mice, ticks, and Borrelia isolates from each island site (and at each time point) will be determined, thus providing a rich resource for evaluating the structure of their respective populations, and the interactions among these species.