Cell separation in Neisseria gonorrhoeae

描述（由申请人提供）：淋病奈瑟菌在男性和女性中引起一种非常常见的性传播疾病，通常会对女性造成严重后果，包括盆腔炎、异位妊娠和不孕症。淋球菌种群正变得越来越耐抗生素，并且出现了多重耐药菌株。本研究旨在了解细胞分离中肽聚糖分解的机制，并将细胞分离作为抗菌治疗的靶点。初步数据表明，细胞分离缺陷使淋病奈瑟菌对抗生素更加敏感，同时也使其在感染人类细胞方面存在缺陷。先前我们证明了淋病奈塞菌中肽聚糖降解基因（amiC或ltgC）的突变会导致异常生长、细胞分离丧失和自溶增加。这些突变体生长在一个大的聚集体中，共享一个相互连接的细胞壁，并在聚集体周围有一个单一的外膜。在这里，我们将1)确定细胞分离所需的两种肽聚糖降解酶（AmiC和LtgC）的生化功能，并开发可用于鉴定这些酶抑制剂的检测方法；2)检测淋球菌细胞中AmiC和LtgC的定位和可能的相互作用，以确定这些酶在细胞分离中的功能，并开发这些酶在细胞中的检测方法。3)确定细胞分离突变体对人类细胞感染和抗生素耐药性的缺陷程度。在本研究中获得的知识和在此开发的检测方法将有助于确定用于治疗淋球菌疾病和对抗具有类似细胞分离机制的其他细菌的抗生素。

DESCRIPTION (provided by applicant): Neisseria gonorrhoeae causes a very common sexually transmitted disease in men and women that often results in severe consequences for women including pelvic inflammatory disease, ectopic pregnancy, and infertility. The gonococcal population is becoming increasingly antibiotic resistant, and multidrug resistant strains have arisen. This proposal seeks to understand the mechanisms of peptidoglycan breakdown involved in cell separation and to develop cell separation as a target for antimicrobial therapy. Preliminary data indicate that defects in cell separation make N. gonorrhoeae more sensitive to antibiotics as well as defective in infection of human cells. Previously we demonstrated that mutations in genes for peptidoglycan degradation - amiC or ltgC - in N. gonorrhoeae cause aberrant growth, loss of cell separation, and increased autolysis. These mutants grow in large aggregates sharing a single interconnected cell wall and with a single outer membrane surrounding the aggregate. Here we will 1) determine the biochemical functions of two peptidoglycan-degrading enzymes, AmiC and LtgC, required for cell separation and develop assays that could be used to identify inhibitors of these enzymes, 2) examine the localization and possible interactions of AmiC and LtgC in gonococcal cells in order to determine the function of these enzymes for cell separation and develop assays for these enzymes in cells, and 3) determine the extent of defects of cell separation mutants for infection of human cells and for resistance to antibiotics. Knowledge gained in this study and assays developed here will facilitate the identification of antibiotics for the treatment of gonococcal diseases and for combating other bacteria that have similar mechanisms of cell separation. PUBLIC HEALTH RELEVANCE: This project will characterize the mechanisms of cell separation in the bacterial species Neisseria gonorrhoeae. These studies will develop methods to identify new antibiotics for treating gonorrhea and related diseases.