Redox stress responses in Clostridium difficile: mechanisms and implications

 描述(由申请人提供)：这项提案的总体目标是询问胃肠道(GI)生态位，建立腹泻病原体艰难梭菌。我们已经确定了一种独特的氧气解毒酶，超氧化物还原酶(SOR)，它促进艰难梭菌在胃肠道中的生存。这项工作的直接影响将是验证SOR和其他氧化还原蛋白作为旨在防止艰难梭菌定植的干预措施的新靶点。提出了三个具体目标。在目标1中，我们将描述氧气和活性氧物种(ROS)暴露对艰难梭菌在胃肠道定位和生存的影响。在目标2中，我们将评估宿主ROS缺乏对艰难梭菌生态位建立的影响。在目标3中，我们将全面绘制艰难梭菌的氧化还原应激反应纲要。所有拟议的研究都将使用我们拥有的艰难梭菌的最新临床分离株。 通过正在进行的疾病监测研究获得。对于AIMS 1和AIMS 2，将使用两个动物模型，并使用我们专门为这些研究开发的新型定植示踪剂，通过活体动物和体外成像跟踪细菌的建立。对于目标3，我们将采用下一代氧化还原蛋白质组学(ROSics)方法。

 DESCRIPTION (provided by applicant): The overall goal of this proposal is interrogate gastrointestinal (GI) niche establishment of the diarrheagenic pathogen, Clostridium difficile. We have identified a unique oxygen detoxifying enzyme, superoxide reductase (SOR), which promotes C. difficile survival in the GI tract. The immediate impact of this work will be to validae SOR and other redox proteins as novel targets for interventions designed to prevent C. difficile colonization. Three Specific Aims are proposed. In Aim 1, we will delineate the impact of oxygen and reactive oxygen species (ROS) exposure on C. difficile localization and survival in the GI tract. In Aim 2, we will assess the impact of host ROS deficiency on C. difficile niche establishment. In Aim 3, we will comprehensively map the C. difficile redox-stress response compendium. All the proposed studies will use recent clinical isolates of C. difficile that we have obtained through ongoing disease surveillance studies. For Aims 1 and 2, two animal models will be employed, and bacterial establishment tracked via live-animal and ex vivo imaging using a novel colonization tracer we have specifically developed for these studies. For Aim 3, we will employ next-generation redox proteomics (ROSics) approaches.