Retrotransposon assay for tick host bloodmeal identification

项目概要/摘要。 莱姆病造成的公共卫生负担在美国东部继续扩大。 需要新的干预措施来减少风险，以补充众所周知的方法， 杀螨应用或个人防护。储库靶向方法，如口服 目前正在开发疫苗接种、通过杀螨剂喂食或遗传修饰 或正在进行实地测试。这些新的策略集中在白色足鼠，Peromyscus leucopus，它被广泛认为是亚成体鹿蜱（硬蜱dammini或 I.肩胛骨），莱姆病和各种其他人畜共患病感染的载体， 事实上，这只老鼠已经被指控为美国东北部的主要老鼠。 莱姆病病原体（伯氏疏螺旋体）以及人类病原体的储存宿主 巴贝西虫病（田鼠巴贝西虫）和鹿蜱病毒脑炎。然而，证据表明，P。 leucopus是亚成体鹿蜱的主要宿主， 这是一种推断，包括从少数地点进行的有限观察。理想 定罪储存宿主的方法是确定所提供血粉的来源 但迄今为止描述的用于蜱的测定方法很差， 可再现或不敏感。我们对这个项目的总体目标是提供一个 更好地了解其他宿主物种相对贡献的自然变异性的手段 莱姆病病原体的传播这是评估成本所必需的， 小鼠靶向干预的益处。我们已经确定宿主反转录转座子可能 通过PCR检测进行靶向，并提供蜱虫在其 上一阶段，现在寻求完善和验证这种分析模式。因此，我们寻求 （1）开发和验证一种灵敏、特异、简单和可重复的逆转录转座子测定法 用于识别寻找宿主的若虫鹿蜱中宿主血餐的残留物;（2）使用此 测定以确定不同研究中心和研究中心内的Peromyscus血液指数（PBI）是否存在差异 （3）通过采取针对性干预措施， 小鼠和测定宿主寻找若虫鹿蜱，然后确定是否有 是宿主的转变虽然我们的直接目标是为鼠标提供一个坚实的理论基础， 针对莱姆病的有针对性的干预措施，检测本身可以更好地适应 了解各种其他蜱传人畜共患病的延续模式。

Project Summary/Abstract. The public health burden due to Lyme disease continues to expand in the eastern United States. New interventions to reduce risk are needed to complement well-known methods such as acaricidal applications or personal protection. Reservoir targeted approaches such as oral vaccination, feed through acaricides or genetic modifications are currently under development or are being field tested. These newer strategies focus on the white footed mouse, Peromyscus leucopus, which is widely regarded as the main host for subadult deer ticks (Ixodes dammini or I. scapularis), the vector for Lyme disease and diverse other zoonotic infections in the northeastern U.S. Indeed, this mouse has been incriminated as the main northeastern U.S. reservoir host for the agent of Lyme disease (Borrelia burgdorferi) as well as for that of human babesiosis (Babesia microti) and deer tick virus encephalitis. However, the evidence that P. leucopus is the main host for subadult deer ticks is largely descriptive using indirect extrapolations and comprise limited observations from a small number of sites. The ideal means of incriminating a reservoir host is to determine the source of the bloodmeal that served to infect the vector but assays that have been described to date for ticks have been poorly reproducible or insensitive. Our overarching goal for this proposed project is to provide a means to better understand natural variability of the relative contribution of other host species on the transmission of the agent of Lyme disease. This is required to evaluate the costs and benefits of mouse targeted interventions. We have determined that host retrotransposons may be targeted by PCR assays and provide specific signatures of the bloodmeal taken by a tick in its previous stage, and now seek to refine and validate this mode of analysis. Accordingly, we seek to (1) develop and validate a sensitive, specific, simple and reproducible retrotransposon assay for identifying the remnants of host bloodmeals in host-seeking nymphal deer ticks; (2) use this assay to determine whether the Peromyscus blood index (PBI) may vary across sites and within sites over time; and (3) experimentally confirm the PBI by undertaking interventions targeted to mice and assaying host seeking nymphal deer ticks thereafter to determine whether there has been a shift in hosts. Although our immediate goal is to provide a solid rationale for mouse targeted interventions against Lyme disease, the assay itself could be adapted to better understand the mode of perpetuation of diverse other tick-borne zoonoses.