Function and regulation of the intrinsic antibiotic resistome of Neisseria gonorrhoeae

淋病奈瑟菌内在抗生素耐药性的功能和调控

基本信息

批准号：
9982208
负责人：
William Maurice Shafer
金额：
$ 46.55万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-07-24 至 2024-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9982208
关键词：
Acinetobacter baumannii Africa Aminoglycoside resistance Aminoglycosides Animals Anti-Bacterial Agents Antibiotic Resistance Antibiotic Therapy Antibiotics Antimicrobial Cationic Peptides Antimicrobial Resistance Azithromycin Bacteria Cefixime Ceftriaxone Cephalosporins Clinical Clinical Trials Communities Country Data Defect Developed Countries Developing Countries Development Disease Drug Targeting Female Future GC gene Gene Expression Generations Genes Genetic Screening Gentamicins Gonorrhea Gram-Negative Bacteria Gynecologic Health Homeostasis Host Defense Human Incidence Infection Infectious Agent Knowledge Laboratories Medical Membrane Modeling Mucous Membrane Multi-Drug Resistance Mus Mutation Nature Neisseria gonorrhoeae Pharmaceutical Preparations Physiological Predisposition Process Proteins Pseudomonas aeruginosa Recording of previous events Regulation Report (document)Reporting Research Resistance Resistance development Resources Sensory Sepsis Sexually Transmitted Diseases Societies Structure Sulfonamides Surface System Techniques Therapeutic Transcriptional Regulation Treatment Protocols United States Vaccines Woman Work antimicrobial attenuation bacterial resistance base cell envelope clinical efficacy clinical practice combat experience human pathogen insight male male health mouse model mutant novel novel therapeutics pathogenic bacteria programs reproductive reproductive tract resistance gene response screening success transcriptome sequencing uptake

项目摘要

Neisseria gonorrhoeae (the gonococcus; [Gc]) causes both localized, uncomplicated infections at mucosal surfaces and more invasive forms of disease that can have severe medical consequences for the reproductive and general health of men and women. In the United States it is estimated that the incidence of gonorrhea is at least 850,000 cases per year while the worldwide incidence in 2012 was reported to be 78 million cases. In addition to the global problems of disease incidence and impact of gonorrhea on human health, Gc strains have developed decreased susceptibility or clinical resistance to front-line antibiotics currently used in dual therapy (e.g., ceftriaxone and azithromycin) in the USA and other developed countries. Our research program is dedicated to understanding the intrinsic systems possessed by Gc that allow it to resist classical antibiotics as well as cationic antimicrobial peptides/proteins (CAMPs) that participate in innate host defense. In the absence of new antibiotics, especially those recognizing unexploited targets, information regarding the development of resistance to existing antibiotics likely to enter clinical practice is critical. For instance, gentamicin has been used extensively in Africa to treat gonorrhea but resistance data from this part of the world is scant. This is unfortunate because gentamicin has been suggested to be an alternative antibiotic for treatment of gonorrhea in developed countries. We have evidence that loss of a sensory two component system (TCS) termed MisR/MisS results in Gc hyper-susceptibility to both gentamicin (as well as other aminoglycosides) and CAMPs, but not other antibiotics. A recent report documented that loss of the MisR/MisS TCS conferred a survival defect on Gc as assessed in a female mouse model of lower genital tract infection. We hypothesize that such attenuation of Gc was due, in part, to a reduced capacity of MisR-negative Gc to regulate genes important for resistance to host-derived CAMPs. The selective sensitivity of MisR-negative Gc to aminoglycosides and CAMPs is consistent with the self-promoted uptake model invoked for how these antimicrobials enter Pseudomonas aeruginosa and traverse the cell envelope. We will now build on the progress made in our initial studies. In Specific Aim 1 we will use genetic screening techniques, an experimental female mouse infection model and analysis of clinical isolates expressing decreased gentamicin susceptibility to further define the repertoire of Gc genes that contribute to intrinsic gentamicin resistance. We hypothesize that the identified genes will encode proteins that participate in cell envelope structure, membrane integrity and membrane homeostasis that work in unison to impact levels of Gc resistance to aminoglycosides and CAMPs. In Specific Aim 2 we will ascertain the responsiveness of Gc to sub-lethal levels of gentamicin and determine the responsible genes. In Specific Aim 3 we will define the physiological consequences of mutations in the identified genes that influence Gc susceptibility to gentamicin. The results from this work will provide basic knowledge as to how human pathogens like Gc control expression of genes involved in intrinsic resistance to antimicrobials.

淋病奈瑟氏菌（淋球菌； [GC]）引起粘膜表面上的局部，简单的感染，以及更具侵入性的疾病形式，这可能会对男性和女性的生殖和一般健康产生严重的医学后果。在美国，据估计，淋病的发生率为每年至少850,000例，而2012年全球发病率为7800万例。除了全球疾病发病率和淋病对人类健康的影响外，GC菌株还降低了对双重治疗中目前使用的前线抗生素的易感性或临床抵抗力（例如，在美国和美国和其他发达国家）。我们的研究计划致力于了解GC拥有的内在系统，该系统允许其抵抗经典的抗生素以及参与先天宿主防御的阳离子抗菌肽/蛋白质/蛋白质（营地）。在缺乏新的抗生素的情况下，尤其是那些识别未开发靶标的抗生素，有关可能进入临床实践的现有抗生素的抗性的信息至关重要。例如，庆大霉素已在非洲广泛用于治疗淋病，但世界各地的抗药性数据很少。这是不幸的，因为庆大霉素被认为是发达国家淋病治疗的替代抗生素。我们有证据表明，被称为MISR/MISS的感官两个组件系统（TC）的丧失导致庆大霉素（以及其他氨基糖苷）和营地的GC超敏度，但没有其他抗生素。最近的一份报告记录，失去MISR/MISS TCS赋予了GC的生存缺陷，如在下生殖道感染的女鼠模型中所评估的那样。我们假设GC的这种衰减部分是由于错误的GC的能力降低了对抗宿主衍生营地重要性重要的基因的能力。误差阴性GC对氨基糖苷和cAMP的选择性敏感性与这些抗微生物剂如何进入铜绿假单胞菌的自我促进的摄取模型一致，并横穿细胞包膜。现在，我们将基于初步研究的进展。在特定目标1中，我们将使用遗传筛查技术，一种实验性雌性小鼠感染模型以及表达降低庆大霉素敏感性降低的临床分离株，以进一步定义有助于内在庆大霉素耐药性的GC基因的曲目。我们假设所鉴定的基因将编码参与细胞包膜结构，膜完整性和膜稳态的蛋白质，这些蛋白质与氨基糖苷和营地的GC抗性水平一致起作用。在特定的目标2中，我们将确定GC对庆大霉素亚致死水平的反应性，并确定负责任的基因。在特定目标3中，我们将定义影响GC易感庆大霉素易感性的已鉴定基因中突变的生理后果。这项工作的结果将提供有关人类病原体（例如GC控制基因内在耐药性）如何控制抗菌药物的基本知识。