Assessing Klebsiella pneumoniae invasion of the intact gut microbiome

项目摘要/摘要 肺炎克雷伯氏菌是医院获得性和抗药性感染的重要原因， 包括肺炎、菌血症和尿路感染。当K。 肺炎杆菌存在于肠道中，肺炎克雷伯菌必须克服许多障碍才能成功地在肠道内定植 肠道，包括肠道微生物群。虽然通过抗生素破坏肠道微生物群可以允许 定植，肺炎克雷伯菌在缺乏抗生素的情况下经常在肠道定植，当一个完整的微生物群 是存在的。我们对肺炎克雷伯菌如何侵入完好的肠道的理解存在一个根本的空白。 微生物组。此外，肺炎克雷伯菌与肺炎克雷伯菌竞争的具体机制 内源性肠道微生物区系仍未被探索。这项提案目的是确定和描述 肺炎克雷伯菌在完整肠道微生物群中定植所需的因素及其决定因素 影响肺炎克雷伯菌肠道适应性的因素。这一提议的中心假设是，金伯利进程雇用了 微生物群依赖和特定的因素，以增强其与宿主微生物区系直接竞争的能力 或者在微生物区系介导的宿主炎症调节下存活下来，入侵完整的肠道微生物群，这是 对KP肠道定植至关重要。我将在三个具体目标中检验这一假设：1)定义以前的 确定肠道健康因子，即在完整肠道微生物群入侵期间的碲抗性(TER)操纵子； 确定TER操纵子在响应生理相关压力中的作用；3)系统地确定 肺炎克雷伯菌在完整肠道菌群入侵过程中的健康因素。这项提案中的工作是创新的， 因为它需要开发新的转座子测序应用，并且它解决了 了解这一点可以改变目前肺炎克雷伯菌肠道定植的模式。完成这项工作 将通过确定、表征和确定K的优先顺序产生持续的积极影响。 肺炎杆菌侵袭肠道微生物群所必需的因素，这将有助于指导发展 旨在破坏肺炎克雷伯菌肠道定植的治疗方法。最后，本方案中的研究 与之相辅相成的是一个全面的培训计划，旨在为追求 研究主要集中在细菌致病机制方面，直接为临床所知，并应用于临床。这 该项目将在密歇根大学内与一个杰出的合作团队一起进行- 导师。这个共同导师团队将通过以下方式补充候选人在宿主-病原体相互作用方面的专业知识 提供微生物生态学方面的培训，探索细菌生理学，并对宿主进行全面分析- 候选人过渡到独立所需的微生物系统。这些最先进的研究将 导致肺炎克雷伯菌允许入侵完整肠道的因子的鉴定和特征 微生物组和微生物组在这一过程中的相应作用，使疗法的设计能够 减少肺炎克雷伯菌病的影响。

Project summary/abstract The bacteria Klebsiella pneumoniae is an important cause of hospital-acquired and antibiotic-resistant infections, including pneumonia, bacteremia, and urinary tract infection. Infection risk sharply increases when K. pneumoniae is present in the gut, and K. pneumoniae must overcome many barriers to successfully colonize the gut, including the gut microbiome. While disruption of the gut microbiome through antibiotics can permit colonization, K. pneumoniae frequently colonizes the gut in the absence of antibiotics when an intact microbiome is present. There is a fundamental gap in our understanding of how K. pneumoniae invades the intact gut microbiome. Furthermore, the specific mechanisms underlying the ability of K. pneumoniae to compete with the endogenous gut microbiota remain unexplored. The objective of this proposal is to identify and characterize factors necessary for K. pneumoniae gut colonization in an intact gut microbiome and determine how these factors influence K. pneumoniae fitness in the gut. The central hypothesis of this proposal is that Kp employs microbiome dependent and specific factors to enhance their ability to directly compete with the host microbiota or survive microbiota-mediated modulation of host inflammation to invade the intact gut microbiome, which is critical for Kp gut colonization. I will test this hypothesis in three specific aims: 1) define the role of a previously identified gut fitness factor, the tellurium resistance (ter) operon during invasion of an intact gut microbiome; 2) determine the role of the ter operon in response to physiologically relevant stresses and; 3) systematically identify K. pneumoniae fitness factors during invasion of intact gut microbiomes. The work in this proposal is innovative, as it requires the development of novel transposon sequencing application, and it addresses a gap in understanding that can shift the current paradigm of K. pneumoniae gut colonization. Completion of this work will have sustained positive impact through the identification, characterization, and prioritization of K. pneumoniae factors necessary for invasion of the intact gut microbiome, which will help guide the development of therapeutics targeted at the disruption of K. pneumoniae gut colonization. Finally, the research in this proposal is complemented by a comprehensive training plan designed to develop a foundational skillset for the pursuit of research focused on mechanisms of bacterial pathogenesis directly informed by and applicable to the clinic. This project will be undertaken within the University of Michigan in conjunction with a distinguished team of co- mentors. This team of co-mentors will complement that candidate's expertise in host-pathogen interaction by providing training in microbial ecology, exploration of bacterial physiology, and comprehensive analyses of host- microbial systems necessary for the candidate's transition to independence. These state-of-the-art studies will lead to the identification and characterization of K. pneumoniae factors that permit the invasion of the intact gut microbiome and the corresponding role of the microbiota in this process to enable the design of therapies to reduce the impact of K. pneumoniae disease.