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

基本信息

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
项目类别：
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

项目摘要

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.

项目概要许多临床相关病原体的染色体中都整合有噬菌体基因组（原噬菌体），这对细菌的表型和适应性有很大影响，因为噬菌体适应性是相关的。为了适应细菌宿主的适应性，噬菌体可以通过减轻宿主的负担来变得更适应。细菌被多个噬菌体感染（即重复感染），争夺宿主资源可能会选择噬菌体与其他噬菌体相比，即使增加了宿主的负担，也更具竞争力。建议是理解并学习利用噬菌体细胞内的进化权衡了解重复感染期间的竞争力和细菌适应性将提供更好的见解。研究原噬菌体如何影响细菌宿主的表型和适应性，并可能为新型噬菌体铺平道路噬菌体治疗方法利用这种权衡使细菌感染更容易治疗。我们建议使用铜绿假单胞菌 (Pa) 及其原噬菌体 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适应性之间的进化权衡。 Pa携带Pf前噬菌体，并且慢性感染Pa的囊性纤维化（CF）患者更多。与急性感染患者相比，Pa 更有可能具有 Pf 噬菌体，这表明 Pf 噬菌体是一个不可或缺的组成部分。 Pa 进化历史和发病机制的一部分该项目的第一部分旨在了解 Pa 是否存在。毒力因子的产生与Pa染色体上携带的Pf原噬菌体的数量相关。从之前资助的一项研究中，我们收集了来自 33 名 CF 患者的 >100 Pa 临床分离株，这些患者携带使用该集合和实验室 Pa 菌株，我们将测试零个、一个或两个 Pf 噬菌体之间的相关性。拷贝数和毒力因子如绿脓菌素和pyoverdine的产生在第二个目标中，我们将。用前噬菌体阻遏基因突变的 Pf 噬菌体重复感染 Pa 实验室菌株 PA14。突变体在宿主细胞内快速复制并大量繁殖，创造了一个有利于选择缺乏衣壳基因的缺陷干扰 (DI) 噬菌体这些 DI 噬菌体是利用的作弊者。公共资源的全长噬菌体，如衣壳，自私地繁殖 Pf 衣壳与临床相关。 Pa 的表型，例如生物膜的稳健性和抗生素耐受性因此，衣壳基因的损失不仅仅是。我们计划通过这种方式使 Pf 噬菌体与其他 Pf 噬菌体相比更具竞争力，但也会影响宿主的适应性。在生物膜和抗生素选择下进化感染这种自私的 Pf 噬菌体的 PA14，以测试衣壳是否随着时间的推移，基因会丢失，破坏生物膜的稳定性和抗生素耐受性。该项目的完成将为噬菌体对其细菌的影响提供有价值的信息利用噬菌体竞争力和宿主之间的进化权衡。适应性可能为噬菌体治疗的新方法铺平道路，类似于基因驱动，该方法利用这种权衡使细菌感染更容易治疗。