Genetic Mechanisms of Gonococcal Resestance to Mediators of Innate Immunity

淋病奈瑟氏菌可引起粘膜表面的局部非复杂感染 侵袭性疾病，包括盆腔炎和播散性淋球菌感染。这个 淋球菌逃避粘膜表面天然宿主防御介质抗菌作用的能力 或在血液中可能对其在感染期间早期存活的能力具有重要意义。在这个项目中，我们 将侧重于确定淋球菌对先天抗菌剂的耐药性机制 宿主防御影响传染性和/或体内适合性。在具体目标1中，我们将测试mtrC-mtrD的作用 外排泵检测淋球菌感染男性尿路的能力。据我们所知，这 将是第一次测试任何微生物外排泵在促进感染方面的重要性 人类。MtrC-mtrD-mtre外排泵赋予淋球菌一种输出疏水性的机制 沐浴的抗生素和宿主衍生的抗菌剂(抗菌肽、胆盐和黄体酮) 粘膜表面。形成泵的蛋白质由mtrCDE操纵子编码，它是 转录上受顺式和法式调控过程的调控。这些监管系统 在下生殖道感染的小鼠模型中调节淋球菌的适合度水平，我们现在将测试 它们还调节人体的体内健康状况。在特定的目标2中，我们将确定突变是否 改变脂低聚糖结构，并已知会导致淋球菌对 正常人血清或阳离子抗菌肽的杀灭作用影响淋球菌的感染性和/或 活体健身。我们假设先天宿主防御系统的中介体在生殖器起作用 作为抗生素的粘膜表面和作为其对淋球菌的抗菌作用的结果， 最终会出现耐药变异株，这些变异株在感染期间具有竞争优势。因此，在 具体目标3我们将分离实验室衍生的淋球菌突变株，这些突变株的敏感性水平发生了变化 宿主衍生的抗菌剂，并测试这些菌株在体内的适合度是否增加或降低。结果是 将为淋球菌适应体内环境的能力提供重要的见解。

Neissena gonorrhoeae causes both localized uncomplicated infections at mucosal surfaces and more invasive forms of disease including pelvic inflammatory disease and disseminated gonococcal infection. The ability of gonococci to evade the antimicrobial action of mediators of innate host defense at mucosal surfaces or in the bloodstream is of likely importance in its ability to survive eariy during infection. In this project we will focus on determining whether mechanisms of gonococcal resistance to antimicrobial agents of innate host defense impact infectivity and/or in vivo fitness. In Specific Aim 1 we will test the role of the MtrC-MtrD MtrE efflux pump in determining the ability of gonococci to Infect the male urethra. To our knowledge, this will be the first test of the importance of any microbial efflux pump in promoting an infection in humans. The MtrC-MtrD-MtrE efflux pump endows gonococci with a mechanism to export hydrophobic antibiotics and host-derived antimicrobials (antimicrobial peptides, bile salts and progesterone) that bathe mucosal surfaces. The proteins that fomn the pump are encoded by the mtrCDE operon, which is transcriptionally regulated by cis- and frans-acting regulatory control processes. These regulatory systems modulate levels of gonococcal fitness in a murine model of lower genital tract infection and we will now test if they also modulate in vivo fitness in humans. In Specific Aim 2 we will determine whether mutations that alter lipooligosaccharide structure and are known to result in changes in gonococcal susceptibility to the killing action of normal human serum or cationic antimicrobial peptides impact gonococcal infectivity and/or in vivo fitness. We hypothesize that mediators of the innate host defense system function at the genital mucosal surface as antibiotics and as a consequence of their antimicrobial action against gonococci, resistant variants ultimately emerge and these have a competitive advantage during infection. Accordingly, in Specific Aim 3 we will isolate laboratory-derived mutants of gonococci with altered levels of susceptibility to host-derived antimicrobials and test if such strains have increased or decreased fitness in vivo. The results will provide important insights regarding the ability of gonococci to adapt to the in vivo environment.