PDF(Pubmed)
Abstract：
The bacterial agent of Lyme disease, Borrelia burgdorferi, exists in an enzootic cycle by adapting to dissimilar mammalian and tick environments. The genetic elements necessary for host and vector adaptation are spread across a bacterial genome comprised of a linear chromosome and essential linear and circular plasmids. The promoter trap system, In Vivo Expression Technology (IVET), has been used to identify promoters of B. burgdorferi that are transcriptionally active specifically during infection of a murine host. However, an observed infection bottleneck effect in mice prevented the application of this system to study promoters induced in a tick environment. In this study, we adapted a membrane-based in vitro feeding system as a novel method to infect the Ixodes spp. vector with B. burgdorferi. Once adapted, we performed IVET screens as a proof of principle via an infected bloodmeal on the system. The screen yielded B. burgdorferi promoters that are induced during tick infection and verified relative expression levels using qRT-PCR. The results of our study demonstrate the potential of our developed in vitro tick feeding system and IVET systems to gain insight into the adaptive gene expression of the Lyme disease bacteria to the tick vector.
摘要：
莱姆病的细菌病原体，伯氏疏螺旋体,通过适应不同的哺乳动物和蜱环境而存在于植物性周期中。宿主和载体适应所必需的遗传元件分布在由线性染色体和必需的线性和环状质粒组成的细菌基因组中。启动子陷阱系统，体内表达技术（IVET），已用于鉴定在鼠宿主感染期间具有转录活性的B.burgdorferi启动子。然而,在小鼠中观察到的感染瓶颈效应阻止了该系统用于研究在蜱环境中诱导的启动子的应用。在这项研究中,我们采用了基于膜的体外饲喂系统作为感染Ixodesspp的新方法。向量与B.burgdorferi。一旦适应，我们通过系统上感染的血粉进行了IVET筛查，以此作为原理证明。筛选产生了在蜱感染期间诱导的伯氏芽孢杆菌启动子,并使用qRT-PCR验证了相对表达水平。我们的研究结果表明，我们开发的体外蜱饲喂系统和IVET系统具有深入了解莱姆病细菌对蜱载体的适应性基因表达的潜力。
