Gonococci: Genetics of Resistance to PMN Proteins

描述(申请人提供)：淋球菌是一种严格的人类病原体，每年在全球范围内导致超过6000万例性传播疾病淋病。在没有有效疫苗的情况下，抗生素治疗仍然是减少或阻断淋球菌在社区中传播的主要机制。不幸的是，由于突变的发展或耐药性决定因素的获得，淋球菌对相对便宜的抗生素产生了抗药性；这种耐药性现在需要使用更昂贵的抗生素，而贫穷国家并不总是可以获得这些抗生素。淋球菌所具有的多药外排泵在淋球菌抵抗天然宿主防御系统的抗生素和抗菌剂的能力中起着重要作用。特别是，我们的工作表明mtrC-mtrD-mtrE外排泵参与了淋球菌对青霉素和大环内酯类抗生素的耐药性。这种外排泵还能识别宿主抗菌素，如抗菌肽和黄体酮。我们已经证明，淋球菌在实验感染的雌性小鼠中引起持续感染是需要泵的，体内适应的程度与控制mtrCDE基因表达的转录调节因子有关。DNA结合蛋白在调节淋球菌对抗菌药耐药性中的重要性是这一竞争性更新应用的主题。在特定的目标1中，我们将定义调控mtrR基因表达的转录调控过程，mtrR基因编码mtrCDE外排泵操作数的抑制子，并可以控制MAR基因以外的许多基因的表达。我们将评估这种调节在淋球菌抵抗抗菌剂的能力以及在实验感染小鼠感染期间的重要性。在具体目标2中，我们将定义mtrCDE操作数转录的不同启动子的用途、调节和生物学意义。在具体目标3中，我们将确定MTRR和其他调节蛋白控制的基因产物影响淋球菌对抗生素和宿主衍生抗菌素敏感性水平的机制。拟议工作的结果将促进我们对淋球菌和其他人类细菌病原体如何使用药物外排泵和转录调控系统来抵抗经典抗生素以及天然免疫介体的了解。 公共卫生相关性：该项目的目标是了解淋球菌如何使用药物外排泵和转录调节器来控制外排泵和其他结构的水平，以抵抗感染期间人类宿主使用的抗生素或抗菌剂。获得的信息将有助于开发新的抗菌剂来治疗或预防淋病，淋病仍然是一个世界性的公共卫生问题。

DESCRIPTION (provided by applicant): Neustria gonorrhoeae is a strict human pathogen that causes greater than sixty million cases worldwide of the sexually transmitted disease gonorrhea each year. Without an effective vaccine, antibiotic therapy remains the principle mechanism to reduce or block the transmission of the gonococcus in the community. Unfortunately, because of the development of mutations or the acquisition of resistance determinants, the gonococcus has developed resistance to relatively inexpensive antibiotics; such resistance now requires the use of more expensive antibiotics that are not always available in poor countries. Multidrug efflux pumps possessed by gonococci have an important role in the ability of gonococci to resist antibiotics and antimicrobials of the innate host defensive system. In particular, our work has shown that the MtrC-MtrD-MtrE efflux pump participates in gonococcal resistance to penicillin and macrolides. This efflux pump also recognizes host antimicrobials, such as antimicrobial peptides and progesterone. We have shown that the pump is required for gonococci to cause a sustained infection in experimentally-infected female mice and the degree of in vivo fitness is linked to transcriptional regulators that control mtrCDE gene expression. The importance of DNA- binding proteins in regulating gonococcal resistance to antimicrobials is the topic of this competitive renewal application. In Specific Aim 1 we will define the transcriptional control processes that modulate expression of the mtrR gene, which encodes a repressor of the mtrCDE efflux pump operand and can control the expression of numerous genes outside of the mar locus. We will assess the importance of such regulation in the ability of gonococci to resist antimicrobials and during infection in experimentally-infected mice. In Specific Aim 2 we will define the use, regulation and biologic importance of distinct promoters for transcription of the mtrCDE operand. In Specific Aim 3 we will define the mechanism which the products of genes controlled by MtrR and other regulatory proteins impact levels of gonococcal susceptibility to antibiotics and host-derived antimicrobials. The results from the proposed work will advance our knowledge regarding how gonococci and other human bacterial pathogens use drug efflux pumps and transcriptional regulatory systems to resist both classical antibiotics as well as mediators of innate immunity. PUBLIC HEALTH RELEVANCE: The goal of this project is to understand how Neustria gonorrhoeae uses drug efflux pumps and transcriptional regulators that control levels of efflux pumps and other structures to resist antibiotics or antimicrobials used by the human host during infection. The information gained will help in the development of new antimicrobials to treat or prevent gonorrhea, which remains a worldwide public health problem.