Exploiting Pf phage superinfection to lower Pseudomonas aeruginosa virulence via evolutionary tradeoffs

利用 Pf 噬菌体重复感染通过进化权衡降低铜绿假单胞菌毒力

• 批准号: 10748681
• 负责人: Nanami Kubota
• 金额: $ 4.77万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10748681
• 关键词: Acute; Affect; Antibiotics; Bacteria; Bacterial Chromosomes; Bacterial Infections; Bacteriophages; Binding; Biological Models; Capsid; Capsid Proteins; Cells; Characteristics; Charge; Chromosomes; Chronic; Clinical; Collection; Cytolysis; Data; Drug Tolerance; Environment; Evolution; Family; Filament; Funding; Genes; Genome; Goals; Growth; Human; Infection; Inoviridae; Inovirus; Learning; Length; Longitudinal Studies; Measurement; Measures; Metadata; Microbial Biofilms; Modeling; Mutation; Parasites; Pathogenesis; Patients; Pharmaceutical Preparations; Phenotype; Population; Prevalence; Production; Prophages; Pseudomonas aeruginosa; Pseudomonas aeruginosa infection; Pyocyanine; Recording of previous events; Reporting; Resources; Testing; Time; Viral Genome; Viral Proteins; Virulence; Virulence Factors; acute infection; antibiotic tolerance; bacterial fitness; clinically relevant; clinically significant; cost; cystic fibrosis patients; fitness; improved; insight; mutant; novel; novel strategies; pathogen; pathogenic bacteria; pressure; prevent; pyoverdin; reproductive; superinfection; whole genome

PROJECT SUMMARY Many clinically relevant pathogens have bacteriophage (phage) genomes integrated in their chromosome (prophages), which can have large effects on the bacteria’s phenotype and fitness. Since phage fitness is tied to bacterial host fitness, phages can become fitter by decreasing their burden on their host. However, when bacteria are infected by multiple phages (i.e., superinfection), competition for host resources may select phages that are more competitive against other phages, even at the increased burden to their host. The objective of this proposal is to understand and learn to exploit the evolutionary tradeoff between phage intracellular competitiveness and bacterial fitness during superinfection. Understanding this tradeoff will give better insight into how prophages influence their bacterial host’s phenotype and fitness, and potentially pave way for a novel approach in phage therapy that utilizes such tradeoffs to make bacterial infections easier to treat. We propose to use Pseudomonas aeruginosa (Pa) and its prophage, Pf phage, as a model system for better understanding the evolutionary tradeoff between phage competitiveness and bacterial fitness. More than half of Pa carry Pf prophages. Furthermore, cystic fibrosis (CF) patients who are chronically infected with Pa were more likely to have Pa that have Pf prophages than acutely infected patients. This hints that Pf phages are an integral part of Pa evolutionary history and pathogenesis. The first part of this project aims to understand whether Pa virulence factor production is correlated with the number of Pf prophages that Pa carries in its chromosome. From a previously funded study, we have a collection of >100 Pa clinical isolates from 33 CF patients that carry zero, one, or two Pf prophages. Using this collection and lab Pa strains, we will test for correlations between Pf copy number and the production of virulence factors like pyocyanin and pyoverdine. In the second aim, we will superinfect Pa lab strain PA14 with Pf phage that has a mutation in the prophage repressor gene. This Pf phage mutant replicates quickly and at high populations within the host cell, creating an environment that favors selection for defective interfering (DI) phages that lack capsid genes. These DI phages are cheaters that exploit full-length phages for public resources, like capsid, to selfishly propagate. Pf capsid is tied to clinically relevant phenotypes of Pa, such as biofilm robustness and antibiotic tolerance. Thus, the loss of capsid genes is not only a way Pf phages become more competitive against other Pf phages but can affect host fitness as well. We plan to evolve PA14 infected with this selfish Pf phage under biofilm and antibiotic selection to test whether capsid genes become lost over time, undermining biofilm stability and antibiotic tolerance. Completion of this project will provide valuable information on the influence prophages have on their bacterial host’s phenotype and fitness. Exploiting the evolutionary tradeoff between phage competitiveness and host fitness may potentially pave way for a novel approach in phage therapy, analogous to a gene drive, that exploits such tradeoffs to make bacterial infections easier to treat.

项目摘要 许多临床上相关的病原体具有整合在其染色体中的噬菌体（噬菌体）基因组 （预言），这可能会对细菌的表型和健身产生巨大影响。由于噬菌体健身被绑在一起 对于细菌宿主健身，噬菌体可以通过减少宿主的燃烧而变得更健康。但是，什么时候 细菌被多个噬菌体感染（即超级感染），宿主资源的竞争可能会选择噬菌体 与其他噬菌体的竞争力更具竞争力，即使在增加了宿主的燃烧时也是如此。这个目的 建议是理解并学会探索细胞内噬菌体之间的进化权衡 超级感染期间的竞争力和细菌健身。了解这种权衡将提供更好的见识 预知如何影响其细菌宿主的表型和健身，并有可能为新颖的方式铺平道路 噬菌体疗法的方法是利用这种权衡使细菌感染更容易治疗的方法。 我们建议使用铜绿假单胞菌（PA）及其先知PF噬菌体作为模型系统，以更好地 了解噬菌体竞争力和细菌健身之间的进化权衡。超过一半 PA携带PF先知。此外，长期感染PA的囊性纤维化（CF）患者更多 比急性感染的患者可能具有具有PF先知的PA。这暗示PF噬菌体是不可或缺的 PA进化史和发病机理的一部分。该项目的第一部分旨在了解PA是否是否 病毒因子的产生与PA携带染色体携带的PF先知数量相关。 从先前资助的研究中，我们收集了来自33位CF患者的> 100 PA临床分离株 零，一个或两个PF先知。使用此集合和实验室PA菌株，我们将测试PF之间的相关性 拷贝数以及诸如增生因素和Pyoverdine等病毒因素的产生。在第二个目标中，我们将 超级感染PA Lab菌株PA14具有PF噬菌体，该噬菌体在先知复制基因中具有突变。这个PF噬菌体 突变体在宿主单元内迅速复制，并在宿主单元内的高种群中创造一个有利于的环境 用于缺乏衣壳基因的干扰（DI）噬菌体的选择。这些DI噬菌体是利用的作弊者 诸如Capsid之类的公共资源的全长噬菌体自私。 PF CAPSID与临床相关 PA的表型，例如生物膜鲁棒性和抗生素耐受性。那就是，衣壳基因的丧失不仅是 PF噬菌体对其他PF噬菌体的竞争力更具竞争力，但也会影响宿主健身。我们计划 在生物膜和抗生素选择下进化感染了这种自私的PF噬菌体的PA14，以测试CAPSID是否 随着时间的流逝，基因损失，破坏了生物膜稳定性和抗生素耐受性。 该项目的完成将提供有关其影响对细菌的影响的有价值的信息 主持人的表型和健身。利用噬菌体竞争力与主机之间的进化权衡 健身可能有可能为一种类似于基因驱动的噬菌体疗法的新方法铺平方法 这样的权衡使细菌感染更容易治疗。