Defining the impact of zinc on Streptococcus agalactiae biofilm and colonization

项目摘要 在怀孕期间，缺锌会增加感染的风险。无乳链球菌， 也被称为B组链球菌(GBS)，定植于20%-30%的孕妇。GBS阴道定植 增加死产、早产和新生儿败血症的风险。GBS可以使用的一种策略来稳定 定植生殖道就是产生生物膜，我们发现GBS生物膜的产生是 在锌存在的情况下被抑制。这一建议检验了GBS生物被膜生产是 受锌的负调控，这种生物膜通过限制固有的 针对GBS的免疫反应。为了验证这一假设，目标1将使用突变和转录 识别调节GBS生物被膜的遗传途径的方法。目标2将定义锌监管的影响 通过评估缺乏CaD的GBS突变体在宿主-微生物界面的生物被膜，CaD是一种锌外排转运蛋白，它 导致生物被膜生产受损。我们将使用人类的体外模型来研究这些相互作用 阴道上皮细胞，移植的人胎膜，和移植的胎儿膜器官 芯片(IFMOC)模型在修改锌利用率的条件下。目标3将使用小鼠的阴道定植 锌转运蛋白CADD在缺锌或缺锌环境下如何影响阴道定植的模型 补充。这些目标的完成将为锌如何影响GBS-宿主相互作用提供新的线索 最终导致生殖道的定居(和感染)。 瑞安·道斯特博士是范德比尔特大学医学中心传染病科的讲师。 他过去的工作是研究妊娠组织对感染的先天免疫反应。该项目将扩展HIS 研究的重点是GBS的定植机制。该项目是对Doster博士临床培训的补充 儿科和成人传染病医学。在大卫·阿罗诺夫博士的指导下，詹妮弗博士 和一个多学科奖学金监督委员会，Doster博士将掌握包括 细菌突变、转录和模拟生殖道内的感染，以确定如何 锌可以改变细菌的生理和发病机制。范德比尔特在以下领域提供尖端技术和专业知识 这些领域通过范德比尔特技术公司的高级基因组学等共享研究核心 设施。这些研究和强大的职业发展计划将为Doster博士过渡到 独立研究员，研究孕期细菌感染的发病机制。

Project Summary During pregnancy, zinc deficiency is associated with an increased risk of infection. Streptococcus agalactiae, also known as Group B Streptococcus (GBS), colonizes 20-30% of pregnant women. GBS vaginal colonization increases the risk for stillbirth, preterm labor, and neonatal sepsis. One strategy that GBS may use to stably colonize the reproductive tract is to produce biofilm, and we have found that GBS biofilm production is suppressed in the presence of zinc. This proposal tests the hypothesis that GBS biofilm production is negatively regulated by zinc, and this biofilm contributes to stable colonization of host tissues by limiting innate immune responses against GBS. To test this hypothesis, Aim 1 will use mutagenesis and transcriptomic approaches to identify genetic pathways regulating GBS biofilm. Aim 2 will define the impact of zinc-regulated biofilm at the host-microbial interface by evaluating GBS mutants lacking cadD, a zinc efflux transporter, which results in impaired biofilm production. We will examine these interactions using in vitro models of human vaginal epithelial cells, explanted human fetal membranes, and an Instrumented Fetal Membrane Organ on a Chip (IFMOC) model under conditions that modify zinc availability. Aim 3 will use a mouse vaginal colonization model to define how the zinc transporter, cadD, impacts vaginal colonization in settings of zinc deficiency or supplementation. Completion of these Aims will shed new light on how zinc impacts GBS-host interactions that culminate in colonization (and infection) of the reproductive tract. Dr. Ryan Doster is an Instructor in the Division of Infectious Diseases at Vanderbilt University Medical Center. His past work investigated gestational tissue innate immune responses to infection. This project will expand his research focus to mechanisms of GBS colonization. This project complements Dr. Doster’s clinical training in pediatrics and adult infectious diseases medicine. Under the mentorship of Dr. David Aronoff, Dr. Jennifer Gaddy, and a multidisciplinary Scholarship Oversight Committee, Dr. Doster will master techniques including bacterial mutagenesis, transcriptomics, and modeling infection within the reproductive tract to determine how zinc alters bacterial physiology and pathogenesis. Vanderbilt offers cutting-edge technology and expertise in these areas through Vanderbilt Technologies for Advanced Genomics and other shared research core facilities. These studies and a strong career development program will prepare Dr. Doster for transition to an independent researcher investigating the pathogenesis of bacterial infections during pregnancy.