Assessing Klebsiella pneumoniae invasion of the intact gut microbiome

项目概要/摘要 肺炎克雷伯氏菌是医院获得性和耐药性感染的重要原因， 包括肺炎、菌血症和尿路感染。当K. pneumoniae存在于肠道中，K.肺炎必须克服许多障碍，成功地殖民 肠道，包括肠道微生物组。虽然通过抗生素破坏肠道微生物组可以允许 colonization，K.肺炎经常在没有抗生素的情况下定殖肠道， 存在。在我们对K.肺炎侵入完整的肠道 微生物组此外，还探讨了K.与肺炎竞争， 内源性肠道微生物群仍未被探索。本提案的目的是确定和描述 K的必要因素。在完整的肠道微生物组中的肺炎肠道定植，并确定这些 影响K.肺炎在肠道中的适应性。该提议的中心假设是Kp采用 微生物组依赖性和特异性因子，以增强其与宿主微生物组直接竞争的能力 或在微生物介导的宿主炎症调节中存活，以侵入完整的肠道微生物组， 对Kp肠道定植至关重要。我将从三个具体目标来检验这一假设：1）定义先前的角色 确定的肠道适应性因子，在完整肠道微生物组入侵期间的碲抗性（ter）操纵子; 2） 确定ter操纵子在响应生理相关应激中的作用; 3）系统地鉴定 K.在完整的肠道微生物组入侵期间的肺炎健身因子。本提案中的工作具有创新性， 因为它需要开发新的转座子测序应用，并且它解决了 理解，可以改变目前的范式K。肺炎菌肠道定植。完成这项工作 将通过K的识别、表征和优先化产生持续的积极影响。 pneumoniae因子是入侵完整肠道微生物组所必需的，这将有助于指导 针对K.肺炎菌肠道定植。最后，本研究建议 是由一个全面的培训计划，旨在发展一个基本的技能，追求 研究集中在直接由临床提供信息并适用于临床的细菌致病机制上。这 该项目将在密歇根大学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： 提供微生物生态学培训，细菌生理学探索，以及宿主的综合分析， 候选人过渡到独立所必需的微生物系统。这些最先进的研究将 对K.允许完整肠道侵入的肺炎因子 微生物组和微生物组在这一过程中的相应作用，以使治疗设计， 降低K的影响。肺炎疾病。

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.