Roles of Phosphate Uptake in Pneumococcal Antibiotic Resistance and Virulence

磷酸盐吸收在肺炎球菌抗生素耐药性和毒力中的作用

• 批准号: 8302505
• 负责人: MALCOLM E. WINKLER
• 金额: $ 23.09万
• 依托单位: TRUSTEES OF INDIANA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8302505
• 关键词: ATP-Binding Cassette Transporters; Address; Animal Model; Antibiotic Resistance; Antibiotics; Area; Attenuated; Bacteria; Bacterial Model; Bacterial Physiology; Biological Process; Cell surface; Culture Media; Data; Development; Disease; Disease Progression; Divalent Cations; Escherichia coli; Future; Genetic; Goals; Gram-Positive Bacteria; Grant; Health; Homeostasis; Human; Human Resources; Immunocompromised Host; In Vitro; Individual; Infection; Ions; Lactams; Link; Literature; Little' s Disease; Manganese; Metabolism; Metals; Methods; Modeling; Molecular Genetics; Monobactams; Mus; Mutation; Pathogenesis; Physiology; Play; Pneumococcal Colonization; Pneumococcal Infections; Population; Pump; Regulation; Regulon; Research; Resistance; Risk; Role; Route; Spectrum Analysis; Streptococcus; Streptococcus pneumoniae; Stress; System; Testing; Time; Toxic effect; Virulence; Work; Zinc; base; divalent metal; experience; in vivo; inorganic phosphate; insight; meetings; mutant; pathogen; pathogenic bacteria; resistance mechanism; respiratory; tool; uptake; vaccine development

DESCRIPTION (provided by applicant): Streptococcus pneumoniae (pneumococcus) is a major human respiratory pathogen that remains a serious health threat worldwide. Resistance of S. pneumoniae to multiple antibiotics is increasing at an alarming rate, and the population of immunocompromised individuals who are at risk for pneumococcal invasive diseases continues to grow. Relatively little is known about the roles played by pneumococcal physiology and metabolism in promoting colonization and virulence of its human host. The overall goal of this grant is to explore the roles played by inorganic phosphate (Pi) uptake and its regulation in the pathogenesis, antibiotic resistance, and metal ion homeostasis of S. pneumoniae. Pi uptake has already been implicated in pneumococcal invasive disease, but little is known about the mechanisms underlying this involvement. Several pieces of evidence show that the regulation of Pi transport in S. pneumoniae is fundamentally different from the mechanisms determined previously for model bacteria, like E. coli and B. subtilis. Therefore, this grant will challenge te current paradigms of Pi uptake that are based on these model bacterial systems and relate Pi uptake to the pathogenesis of S. pneumoniae for the first time. In addition, this work will validat and explore a new mechanism of pneumococcal ¿-lactam resistance about which nothing is known. Finally, this grant draws together several recent ideas from the scientific literature to formulate the hypothesis that cellular Pi uptake and Pi cellular amount are tied to the availabilit and toxicity of several key divalent cations, including zinc (Zn2+) and manganese (Mn2+). Four Specific Aims will be met by this grant. Aim 1 will determine whether two predicted Pi ABC transporter pumps (designated as Pst1 and Pst2) separately uptake Pi in S. pneumoniae and whether this uptake is coordinated. Another goal of Aim 1 is to develop a powerful genetic toolbox and a conceptual framework about Pi uptake and its regulation that will allow effective exploration of the topics in Aims 2-4. Aim 2 will determine the roles of the Pst1 and Pst2 Pi transporters and the likely regulators (designated as PnpRS, PhoU1, and PhoU2) in pneumococcal colonization and virulence. Aim 2 will also determine whether there are additional routes of Pi uptake during infection, besides Pst1 and Pst2. Aim 3 will determine whether increased expression of the Pst1 transporter is responsible for resistance to ¿-lactam antibiotics and whether the Pst2 transporter also plays a role. Aim 4 will explore whether there are links between Pi uptake and cellular amount and divalent metal ion homeostasis. There is a high likelihood of obtaining publishable data from this work that will serve as the basis for a future RO1 application and open up a significant new research area in S. pneumoniae. In addition, this grant has the potential to provide new targets for antibiotic and vaccine development and to provide information about an uncharacterized mechanism of ¿-lactam antibiotic resistance in this important opportunistic pathogen. PUBLIC HEALTH RELEVANCE: The Gram-positive bacterium Streptococcus pneumoniae (pneumococcus) is a major human respiratory pathogen to which antibiotic resistance is increasing at an alarming rate. The overall goal of this grant is to explore the roles played by inorganic phosphate (Pi) uptake and its regulation in the pathogenesis, antibiotic resistance, and metal homeostasis of Streptococcus pneumoniae. Besides providing insights into important biological processes, this grant has the potential to provide new cell-surface targets for antibiotc and vaccine development and to provide new information about an uncharacterized mechanism of ¿-lactam antibiotic resistance in this opportunistic primary pathogen.

描述（由申请人提供）：肺炎链球菌（肺炎球菌）是一种主要的人类呼吸道病原体，在全世界范围内仍然构成严重的健康威胁。肺炎链球菌对多种抗生素的耐药性正在以惊人的速度增加，并且面临肺炎球菌侵袭性疾病风险的免疫功能低下个体的数量持续增长。关于肺炎球菌生理学和代谢在促进其人类宿主定植和毒力方面所起的作用，人们知之甚少。该资助的总体目标是探索无机磷酸盐（Pi）吸收及其在肺炎链球菌发病机制、抗生素耐药性和金属离子稳态中的调节作用。 Pi 的摄取已经与肺炎球菌侵袭性疾病有关，但人们对这种参与的机制知之甚少。多项证据表明，肺炎链球菌中 Pi 转运的调节与之前为模型细菌（如大肠杆菌和枯草芽孢杆菌）确定的机制有根本不同。因此，这项资助将挑战目前基于这些模型细菌系统的 Pi 吸收范式，并首次将 Pi 吸收与肺炎链球菌的发病机制联系起来。此外，这项工作将验证和探索一种尚不清楚的肺炎球菌β-内酰胺耐药的新机制。最后，这项资助汇集了科学文献中的几个最新想法，提出了这样的假设：细胞 Pi 吸收和 Pi 细胞量与几种关键二价阳离子的可用性和毒性有关，包括锌 (Zn2+) 和锰 (Mn2+)。这笔赠款将实现四个具体目标。目标 1 将确定两个预测的 Pi ABC 转运泵（指定为 Pst1 和 Pst2）是否分别摄取肺炎链球菌中的 Pi 以及这种摄取是否协调。目标 1 的另一个目标是开发一个强大的遗传工具箱和一个关于 Pi 吸收及其调节的概念框架，这将允许有效探索目标 2-4 中的主题。目标 2 将确定 Pst1 和 Pst2 Pi 转运蛋白以及可能的调节因子（指定为 PnpRS、PhoU1 和 PhoU2）在肺炎球菌定植和毒力中的作用。目标 2 还将确定除了 Pst1 和 Pst2 之外，感染过程中是否还有其他 Pi 摄取途径。目标 3 将确定 Pst1 转运蛋白表达的增加是否与β-内酰胺抗生素耐药性有关，以及 Pst2 转运蛋白是否也发挥作用。目标 4 将探讨 Pi 摄取与细胞数量和二价金属离子稳态之间是否存在联系。从这项工作中获得可发表的数据的可能性很大，这些数据将作为未来 RO1 应用的基础，并开辟肺炎链球菌的一个重要的新研究领域。此外，这笔赠款有可能为抗生素和疫苗的开发提供新的目标，并提供有关这种重要机会性病原体中β-内酰胺抗生素耐药性的未知机制的信息。 公共卫生相关性：革兰氏阳性菌肺炎链球菌（肺炎球菌）是一种主要的人类呼吸道病原体，其抗生素耐药性正在以惊人的速度增加。该资助的总体目标是探索无机磷酸盐（Pi）吸收及其在肺炎链球菌发病机制、抗生素耐药性和金属稳态中的调节作用。除了提供对重要生物过程的见解外，这笔资助还有可能为抗生素和疫苗开发提供新的细胞表面靶标，并提供有关这种机会性主要病原体中β-内酰胺抗生素耐药性的未知机制的新信息。