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对健康构成严重威胁，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，并且免疫功能低下的人群处于这种状态。肺炎球菌侵袭性疾病的风险持续增加，但人们对肺炎球菌生理学和代谢在促进定植和传播方面所起的作用知之甚少。这项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作用。在肺炎球菌侵袭性疾病中，但人们对这种参与机制知之甚少，一些证据表明，肺炎链球菌中 Pi 转运的调节与之前针对模型细菌确定的机制有根本不同。因此，这项资助将挑战基于这些模型细菌系统的当前 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。验证并探索肺炎球菌的新机制 ¿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 摄取和 Pi 细胞数量与几种关键二价阳离子的可用性和毒性有关，包括锌（此项资助将满足四个特定目标：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 Pi。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，以便有效探索目标 2-4 中的主题。确定 Pst1 和 Pst2 Pi 转运蛋白以及可能的调节因子（称为 PnpRS、PhoU1 和 PhoU2）在肺炎球菌定植和毒力中的作用。除了 Pst1 和 Pst2 之外，Aim 2 还将确定感染过程中是否存在其他 Pi 摄取途径。 Aim 3 将确定 Pst1 转运蛋白表达的增加是否导致 ¿ -内酰胺抗生素以及 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很有可能。为未来 RO1 的应用奠定基础，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，并提供有关未知机制的信息。 -这种重要的机会性病原体中的内酰胺抗生素耐药性。 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。这项资助的总体目标是探索无机磷酸盐 (Pi) 吸收所发挥的作用。及其对肺炎链球菌发病机制、抗生素耐药性和金属稳态的调节除了提供对重要生物过程的见解外，这项资助还有潜力。为抗生素和疫苗的开发提供新的细胞表面靶标，并提供有关尚未表征的机制的新信息-这种机会性主要病原体的内酰胺抗生素耐药性。