Regulation of biofilm formation and pathogenesis in Bordetella pertussis

 描述(申请人提供)：革兰氏阴性杆菌百日咳杆菌是一种人类限制性病原体，可引起严重的呼吸道感染和百日咳或百日咳。最近百日咳杆菌感染和疾病在美国和其他高收入国家的增加，以及对当前商业百日咳疫苗免疫力的减弱，需要对这种细菌使用的致病机制进行研究。我们的总体假设是，生物膜的形成对于呼吸道的持续定植和百日咳杆菌的发病是必不可少的。BpsR是一种高度保守的转录调控因子，它控制着以动物为主的支气管败血杆菌的生物膜发育。此外，BpsR还双重激活或抑制大量基因的表达，这些基因在毒力、转录调节、代谢和其他细胞过程中发挥作用。关于BpsR在百日咳杆菌中的作用尚不清楚。由于不能构建缺乏bpsR基因的突变株，百日咳杆菌中bpsR的功能研究一直受到阻碍。这表明bpsR是百日咳杆菌的必需基因。我们推测，BpsR通过调节参与基本代谢途径、致病机制和生物膜形成的基因的表达，控制百日咳杆菌在呼吸道中的生存能力。在具体目标1中，我们将利用四环素依赖的条件沉默系统来研究它在实验室生长、基因表达和生物膜发育中的作用。在具体目标2中，这些研究将扩展到百日咳杆菌鼻腔感染和生物膜发育的小鼠模型，以确定其在呼吸器官生物膜的定植和形成中的作用。

 DESCRIPTION (provided by applicant): The Gram-negative bacterium Bordetella pertussis is a human restricted pathogen that causes severe respiratory infection and the disease known as whooping cough or pertussis. The recent rise in B. pertussis infections and the disease in the USA and other high income countries, along with waning immunity to current commercial pertussis vaccines necessitate research on understanding the pathogenic mechanisms employed by this bacterium. Our overall hypothesis is that the formation of biofilms is essential for persistent colonization of the respiratory tract and pathogenesis of B. pertussis. Control of biofilm development in the largely animal pathogen B. bronchiseptica is mediated by BpsR, a highly conserved transcriptional regulator. Additionally, BpsR dually activates or represses the expression of a large number of genes which have roles in virulence, transcriptional regulation, metabolic and other cellular processes. Nothing is known about the role of BpsR in B. pertussis. Functional studies of BpsR in B. pertussis have been hindered by the inability to construct a mutant strain lacking the bpsR gene. This suggests that bpsR is an essential gene in B. pertussis. We hypothesize that by regulating the expression of genes involved in essential metabolic pathways, pathogenesis and biofilm formation, BpsR controls the ability of B. pertussis to survive in the respiratory tract. In Specific Aim 1, we will utilize a tetracycline dependent conditional silencing system to examine its role in laboratory growth, gene expression and biofilm development. In Specific Aim 2, these studies will be extended to an intranasal mouse model of B. pertussis infection and biofilm development to identify its role in colonization of and formation of biofilms on respiratory organs.