Molecular Pathogenesis of E. Coli UTI

描述（由申请人提供）：尿路感染（UTI）是最常见的肾脏和泌尿系统疾病，大肠杆菌是迄今为止最常见的病原体。高危人群包括新生儿、学龄前女童、性活跃妇女、老年妇女和男性。所有女性中有一半至少经历过一次尿路感染，导致每年680万次医生就诊，130万次急诊室就诊，245,000次住院，年费用为24亿美元。抗生素耐药性的出现，对药物的过敏反应，正常肠道菌群的改变，以及未能预防复发性感染的发生，证明了有效预防的必要性。有几个群体在没有明显或持久保护的情况下进行了疫苗接种。在这里，我们提出了一个计划，系统地鉴定在体内合成的表面暴露蛋白，并对尿路致病性大肠杆菌菌株具有特异性。表面暴露蛋白将通过以下方法确定：筛选与慢性感染小鼠血清反应的外膜蛋白；生物信息学预测表面表达蛋白；通过有限的蛋白水解释放表面表达的结构域。满足这些顺序筛选的候选抗原将用于在已建立的小鼠尿路感染模型中接种疫苗。作为具体目标，我们提出：1)鉴定在尿路致病性大肠杆菌菌株中体内合成并保守的表面暴露蛋白；2)确定候选蛋白作为多价亚单位疫苗成分预防尿路感染的功效。我们的目标是在预防尿路感染的多价亚单位疫苗中加入最具保护性的抗原。

DESCRIPTION (provided by applicant): Urinary tract infection (UTI) is the most frequently diagnosed kidney and urologic disease and Escherichia coli is by far its most common etiologic agent. Individuals at high risk include neonates, preschool girls, sexually active women, and elderly women and men. Half of all women experience at least one UTI, leading to 6.8 million annual physician visits, 1.3 million emergency room visits, and 245,000 hospitalizations with annual costs of $2.4 billion. Emergence of antibiotic resistance, allergic reaction to pharmaceuticals, alteration of normal gut flora, and failure to prevent recurrent infections document the need for effective prevention. Vaccination has been approached by several groups without marked or long lasting protection. Here, we present a plan to systematically identify surface-exposed proteins that are synthesized in vivo and are specific to uropathogenic strains of E. coli. Surface-exposed proteins will be determined by: screening for outer membrane proteins that react with sera from chronically infected mice; predicting surface-expressed proteins bioinformatically; and releasing surface-expressed domains by limited proteolysis. Candidate antigens that meet these sequential screens will be used for vaccination in the established murine model of urinary tract infection. As Specific Aims, we propose to: 1) Identify surface- exposed proteins that are synthesized in vivo and conserved among uropathogenic E. coli strains; and 2) Determine the efficacy of candidate proteins as components of a multivalent subunit vaccine to protect against urinary tract infection. Our goal will be to include the most protective antigens in a multivalent subunit vaccine for prevention of UTI by uropathogenic E. coli. PUBLIC HEALTH RELEVANCE: Urinary tract infection (UTI) is the most frequently diagnosed kidney and urologic disease and Escherichia coli is by far its most common etiologic agent. Individuals at high risk include neonates, preschool girls, sexually active women, and elderly women and men. Half of all women experience at least one UTI, leading to 6.8 million annual physician visits, 1.3 million emergency room visits, and 245,000 hospitalizations with annual costs of $2.4 billion. Emergence of antibiotic resistance, allergic reaction to pharmaceuticals, alteration of normal gut flora, and failure to prevent recurrent infections document the need for effective prevention. Vaccination has been approached by several groups without marked or long lasting protection. Here, we present a plan to systematically identify surface-exposed proteins that are synthesized in vivo and are specific to uropathogenic strains of E. coli for use in a vaccine to prevent urinary tract infection.