Plasmid encoded biofilm formation by the intestinal Bacteroidales and its importance in community ecology and resilience

肠道拟杆菌的质粒编码生物膜形成及其在群落生态和恢复力中的重要性

• 批准号: 10597098
• 负责人: Leonor Garcia-Bayona
• 金额: $ 9.92万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-25 至 2024-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10597098
• 关键词: Adhesives; Affect; Anabolism; Antibiotic Therapy; Antibiotics; Architecture; Bacteroides; Bar Codes; Biopsy; Cells; China; Colon; Communities; Costs and Benefits; DNA; Data; Dissection; Ecology; Ecosystem; Evolution; Exclusion; Food; Frequencies; Gene Exchanges; Genes; Gnotobiotic; Health; Health Benefit; Horizontal Gene Transfer; Human; Human Volunteers; Image; In Vitro; Individual; Inflammation; Inflammatory; Intervention; Intestines; Japanese; Knowledge; Life; Link; Location; Mediating; Mentors; Methods; Microbe; Microbial Biofilms; Microscopy; Mobile Genetic Elements; Mucous body substance; Mus; Persons; Phenotype; Physiologic pulse; Plasmids; Play; Polysaccharides; Population; Population Dynamics; Role; Sampling; Shapes; Site; Stains; Stress; Structure; Surface; Techniques; Testing; Therapeutic Intervention; Training; Visualization; cohort; cost; design; experimental study; extracellular; fitness; genetic element; gut bacteria; gut microbiome; gut microbiota; host-microbe interactions; human microbiota; human subject; improved; in vitro Assay; interest; member; microbial; microbial community; microbiome; microbiome components; microbiota; mouse model; mucosal biofilms; particle; polymicrobial biofilm; preservation; promote resilience; resilience; sample fixation; skills; stressor; synergism; targeted treatment

Project Summary/Abstract The intestinal microbiota plays a major role in human health and is therefore the focus of significant interest as a target for therapeutic interventions. However, our understanding at the mechanistic level of the ecological and evolutionary forces shaping this diverse and densely colonized ecosystem is still tenuous. Notably, although we know that horizontal gene transfer is pervasive in the gut community, we understand only superficially the different roles of the majority of these exchanged genes and how this repertoire affects community dynamics. Similarly, little is known about the mechanisms underlying community resiliency. This question is particularly intriguing for the Bacteroidales, the most abundant Gram-negative gut microbiome members, which can stably colonize for decades. This proposal will investigate the importance of biofilm formation by the Bacteroidales for community ecology and resilience, focusing on the conjugative megaplasmid pMMCAT which enables biofilm formation in the strains that acquire it. This plasmid is exceptional because of the high frequency of intrapersonal transfer to multiple Bacteroidales species and its ubiquity, with conserved architecture, across global human populations. Some studies suggest that mucosal biofilms in healthy humans are rare, but there is little information about other locations or unattached biofilms. I hypothesize that this megaplasmid, shared among many species in a community, enables the formation of multi-species biofilms and plays a role in community cooperation, notably through increasing community resilience. To test this hypothesis, or otherwise understand alternative roles of pMMCAT, I will systematically characterize the phenotypes conferred by this plasmid in culture and in gnotobiotic mice in a single strain (aim 1) or in different Bacteroidales consortia where some strains carry it (aim 2). To understand the ecological role of pMMCAT, I will evaluate if its conferred phenotypes are synergized or inhibited by the co-resident strains and whether all, only some, or none of the other strains benefit. To visualize biofilms in the colon prior to and following a stress pulse, I will use two different methods to preserve the spatial structure of the gut community and use a biofilm matrix-specific stain. I will subsequently examine the evolutionary dynamics of pMMCAT transfer in these consortia (aim 3). To this end, I will directly quantify and visualize plasmid transfer in culture and in a gnotobiotic mouse. I will also quantify the cost of carrying pMMCAT and expressing biofilm formation genes. I will evaluate the impact of the introduction of a cheater strain that doesn’t pay this fitness cost of producing the biofilm matrix public good. Finally, I will track the evolution of pMMCAT over the course of twelve years in four human volunteers previously found to have pMMCAT-harboring strains. This dissection of the dynamics and mechanisms underlying plasmid-encoded biofilm formation in the gut will improve our current understanding of intestinal ecology and its recent changes in human populations, and will provide one more stepping stone towards targeted microbiome interventions for health benefits.

项目摘要/摘要 肠道微生物群在人类健康中起着重要作用，因此是引人注意的重点 治疗干预措施的目标。但是，我们对生态学水平的理解 塑造这一多样化和良好殖民的生态系统的进化力仍然很脆弱。尤其， 尽管我们知道水平基因转移在肠道社区中普遍存在，但我们只能理解 从表面上看，大多数交换基因的角色以及该曲目如何影响 社区动态。同样，关于社区弹性的基本机制知之甚少。这 问题特别吸引了细菌，这是最丰富的革兰氏阴性肠道微生物组 成员可以稳定地殖民数十年。该建议将调查生物膜的重要性 拟菌体为社区生态学和弹性而形成，重点是共轭 Megaplasmid PMMCAT可在获取它的菌株中形成生物膜。该质粒是 由于人际转移到多种细菌种类及其的频率很高，因此 无处不在，具有配置的体系结构，遍及全球人口。一些研究表明粘膜 健康人的生物膜很少见，但是关于其他位置或未连接的生物膜的信息很少。我 假设这种大质质在一个社区中的许多物种中共享，使得 多种物种生物膜并在社区协调中发挥作用，特别是通过增加社区 弹力。为了检验这一假设，或以其他方式了解PMMCAT的替代作用，我将系统地 表征该质粒在培养物和gnotobiotic小鼠中赋予的表型（AIM） 1）或在不同的细菌伴侣中，有些菌株携带它（AIM 2）。了解生态角色 在PMMCAT中，我将评估其赋予的表型是否被共同居民菌株协同或抑制 以及全部，仅或其他菌株是否受益。在结肠之前可视化生物膜和 压力脉冲后，我将使用两种不同的方法来保留肠道社区的空间结构 并使用生物膜基质特异性染色。随后，我将检查PMMCAT的进化动力学 在这些财团中转移（AIM 3）。为此，我将直接量化和可视化培养物中的质粒转移 并在gnotobiotic小鼠中。我还将量化携带PMMCAT和表达生物膜形成的成本 基因。我将评估引入骗子菌株的影响，该作用不支付这种健身费用 生产生物膜矩阵公共商品。最后，我将在十二个过程中跟踪PMMCAT的演变 以前在四名人类志愿者中发现有PMMCAT-HARBORING菌株的多年。这种解剖 肠道中质粒编码的生物膜形成的动力和机制将改善我们的电流 了解肠生态学及其在人类人群中的最新变化，并将提供更多 踏上针对有针对性的微生物组干预措施以实现健康益处的垫脚石。