Identifying host human products responsible for natural transformation of resistance traits in Acinetobacter spp

鉴定负责不动杆菌属抗性特征自然转化的宿主人类产品

• 批准号: 10331710
• 负责人: Maria Soledad Ramirez
• 金额: $ 10.65万
• 依托单位: CALIFORNIA STATE UNIVERSITY FULLERTON
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-02-07 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10331710
• 关键词: Acinetobacter; Acinetobacter Infections; Acinetobacter baumannii; Address; Affinity; Antibiotic Resistance; Bacteria; Bacterial Antibiotic Resistance; Biotin; Cell Surface Proteins; Cell Surface Receptors; Cells; Centers for Disease Control and Prevention (U.S.); ChIP-seq; Characteristics; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; Code; Competence; Complementary RNA; Complex; Conjugating Agent; DNA; DNase-I Footprinting; Data; Development; Drops; EMSA; Enterobacteriaceae; Environment; Funding; Future; Gene Expression; Genes; Genetic; Genetic Transcription; Genome; Genomics; Gram-Positive Bacteria; Health; Human; Infection; Integration Host Factors; Knowledge; Ligands; Light; Link; Liquid substance; Mass Spectrum Analysis; Mediating; Membrane; Methodology; Molecular; Multi-Drug Resistance; Multidrug-resistant Acinetobacter; Nosocomial Infections; Pathway interactions; Physiology; Play; Process; Reporting; Repression; Resistance; Role; Serum Albumin; Signal Transduction; Signaling Molecule; Streptavidin; Surface; System; Techniques; Testing; Therapeutic; Virulence; antimicrobial drug; base; crosslink; differential expression; extracellular; insight; mutant; novel strategies; opportunistic pathogen; pathogen; pathogenic bacteria; promoter; receptor; resistance gene; response; tool; trait; transcription factor; transcriptome sequencing; treatment strategy; uptake

Project summary/Abstract In recent years, a massive increase in the emergence of antibiotic resistant bacteria has been observed in clinical settings. Acinetobacter baumannii is one of the most widespread pathogens that cause these alarming infections. This bacterium is characterized by its extreme genome plasticity, facilitated by horizontal genetic transfer (HGT) processes. These characteristics are the cause of A. baumannii's remarkable ability to acquire antibiotic-resistance genes. Despite the relevance of foreign DNA acquisition to the pathobiology of A. baumannii, efforts to elucidate the mechanism/s involved in natural transformation have been scarce. We have recently demonstrated that the presence of human serum albumin (HSA) in extracellular host fluids correlates with an increase in A. baumannii natural transformation. We have also observed that the expression of the A. baumannii transcriptional regulator H-NS drops in response to HSA and that competence-associated gene expression increases in the h-ns mutant strains. This observation suggests that changes in cell's H-NS levels may play a central role in natural transformation. Hence, we hypothesize that the interaction of HSA with bacterial surface components triggers a regulatory signaling cascade that decreases H-NS expression, resulting in enhanced expression of genes involved in natural competence. To test this hypothesis, we will examine the interaction of HSA with A. baumannii cell surface proteins using the receptor activity- directed affinity tagging (re-tagging) technique (aim 1). To better understand the transcriptional response cascade responsible for HSA-mediated increase in transformation efficiency, we will determine the H-NS regulated genes associated with competence using complementary RNA-seq and ChIP-seq analyses in wild-type or h-ns mutants (aim 2). The studies proposed in this application will shed light on host adaptation processes leading to antibiotic resistance in this challenging pathogen of increasing relevance worldwide. We will provide new insights into bacterial components acting at the top of the HSA signaling cascade and H-NS's role in HSA-mediated transcriptional responses, leading to an increase in DNA-uptake. Future studies can then use these findings to develop novel approaches to treat severe Acinetobacter human infections, particularly those caused by emerging multidrug-resistant isolates.

项目摘要/摘要 近年来，抗生素抗性细菌的出现大量增加 在临床环境中观察到。 baumannii是杆菌，是最广泛的病原体之一 引起这些令人震惊的感染。该细菌的特征是其极端的基因组可塑性， 通过水平遗传转移（HGT）过程促进。这些特征是A的原因。 鲍曼尼（Baumannii）获得抗生素抗性基因的非凡能力。尽管外国有意义 DNA获取为鲍曼尼a。 自然转变已经稀缺。我们最近证明了人类的存在 细胞外宿主流体中的血清白蛋白（HSA）与a。baumannii天然的增加相关 转型。我们还观察到鲍曼尼曲霉的转录的表达 调节剂H-NS响应于HSA，并且能力相关的基因表达增加 在H-NS突变菌株中。该观察结果表明，细胞H-NS水平的变化可能会播放 自然转化中的中心作用。因此，我们假设HSA与细菌的相互作用 表面成分触发一个调节信号级联，可降低H-NS表达， 导致涉及自然能力的基因表达增强。为了检验这一假设，我们 将使用受体活动 - 定向亲和力标记（重新标记）技术（AIM 1）。更好地理解转录 响应级联负责HSA介导的转化效率提高，我们将 使用互补RNA-Seq和 野生型或H-NS突变体中的CHIP-SEQ分析（AIM 2）。本应用中提出的研究将 阐明宿主的适应过程，导致这种挑战性的病原体抗生素耐药性 在全球范围内增加相关性。我们将提供有关作用于作用的细菌成分的新见解 HSA信号级联和H-NS在HSA介导的转录响应中的作用的顶部 增加DNA摄取。然后，未来的研究可以使用这些发现来发展新颖 治疗严重的杆菌感染的方法，尤其是由出现的方法 多用物抗性分离株。