COBRE: UID: PROJ 1: EVOLUTION OF ANTIBIOTIC RESISTANCE PLASMID HOST RANGE

COBRE：UID：项目 1：抗生素抗性质粒宿主范围的进化

• 批准号: 8359572
• 负责人: Eva M. Top
• 金额: $ 18.61万
• 依托单位: UNIVERSITY OF IDAHO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-02-01 至 2012-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8359572
• 关键词: Address; Affect; Antibiotic Resistance; Bacteria; Centers of Research Excellence; Communicable Diseases; DNA Sequence; Drug resistance; Effectiveness; Evolution; Funding; Genes; Goals; Grant; Human; Multi-Drug Resistance; National Center for Research Resources; Parasites; Pharmacotherapy; Plasmids; Principal Investigator; Process; Proteins; Public Health; Replication Initiation; Replicon; Research; Research Infrastructure; Resistance; Resources; Source; Testing; Time; United States National Institutes of Health; Work; cost; fight against; helicase; improved; mathematical model; mutant; pathogen

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Conjugative transfer of antibiotic resistance genes by plasmids has greatly contributed to the rapid spread of drug resistance among bacterial pathogens, thereby decreasing the effectiveness of various treatment options for infectious diseases in humans. While some plasmids only transfer and stably replicate in a narrow range of hosts (NHR), so-called broad-host-range (BHR) plasmids transfer and replicate in distantly related bacteria, thereby shuffling resistance genes across taxonomic barriers. Our long-term goal is to limit the rapid spread of multi-drug resistance to important human pathogens, but first a fundamental understanding of the evolution of plasmid host range is essential. Our overall hypothesis is that the host range of plasmids can evolve, much like that of parasites, to become wider or narrower over evolutionary time. To test this hypothesis, we propose the following specific aims: 1) To elucidate evolutionary changes that permit a narrow-host-range plasmid to expand or shift its host range, and 2) To elucidate evolutionary changes that cause host range contraction of a broad-host-range plasmid as a result of long-term association with a single host. To address the first aim, we will evolve the NHR mini-replicon mini-F in four bacterial hosts that show different initial levels of plasmid stability. The DNA sequences of the evolved plasmids will be determined to identify genotypic changes that cause a host range shift or expansion. We postulate that plasmid adaptation resulting in improved stability in one poor host will also improve the stability in other hosts. Under Specific Aim 2, we will examine evolved mutants of the BHR mini-replicon mini-pBP136 that were recently shown to have undergone a shift in host-range. We postulate that the observed shift is due to changes in the interaction of the replication initiation protein TrfA1 with the host helicase. For both Aims mathematical models and statistical analyses will be developed and used to identify the parameters that affect these evolutionary processes. Relevance to public health: This work will unravel the mechanisms of plasmid-host interactions that determine the host range of multi-drug resistance plasmids. This may reveal attractive targets for specific drug therapy in the fight against the alarming spread of drug resistance in human pathogens.

该副本是利用资源的众多研究子项目之一 由NIH/NCRR资助的中心赠款提供。对该子弹的主要支持 而且，副投影的主要研究员可能是其他来源提供的 包括其他NIH来源。 列出的总费用可能 代表subproject使用的中心基础架构的估计量， NCRR赠款不直接向子弹或副本人员提供的直接资金。 质粒对抗生素耐药性基因的共轭转移极大地有助于耐药性在细菌病原体中的迅速传播，从而降低了人类传染病的各种治疗选择的有效性。尽管某些质粒仅在狭窄的宿主（NHR）中转移并稳定复制，但所谓的宽宿主（BHR）质粒转移并在远距离相关的细菌中复制，从而在分类障碍物中调整耐药基因。我们的长期目标是限制多药耐药性对重要人类病原体的迅速传播，但首先是对质粒宿主范围演变的基本理解是必不可少的。我们的总体假设是，质粒的宿主范围可以像寄生虫相似，在进化时代变得更宽或更狭窄。为了检验这一假设，我们提出了以下特定目的：1）阐明允许狭窄的宿主范围质粒扩大或移动其宿主范围的进化变化，以及2）阐明进化变化，从而导致与单个宿主长期缔合的宽敞宿主质粒的宿主范围收缩。为了解决第一个目标，我们将在四个细菌宿主中进化NHR迷你替代微型-F，这些细菌宿主显示出不同的初始质粒稳定性水平。将确定进化质粒的DNA序列，以识别导致宿主范围移动或扩展的基因型变化。我们假设质粒适应导致一个较差的宿主的稳定性提高也将改善其他宿主的稳定性。在特定的目标2下，我们将检查BHR迷你替代迷你PBP136的进化突变体，这些突变体最近被证明已经发生了宿主范围的变化。我们假设观察到的移位是由于复制起始蛋白TRFA1与宿主解旋酶的相互作用的变化所致。对于两个目标模型和统计分析，都将开发并用于识别影响这些进化过程的参数。与公共卫生的相关性：这项工作将揭示确定多药抗性质粒宿主范围的质粒相互作用的机制。这可能揭示了在与人类病原体中耐药性的惊人传播中战斗中特异性药物治疗的有吸引力的靶标。