Mechanisms of the Development and Maintenance of Salmonella Gallbladder Carriage

沙门氏菌胆囊运输的发生和维持机制

基本信息

批准号：
10614101
负责人：
JOHN S GUNN
金额：
$ 7.25万
依托单位：
RESEARCH INST NATIONWIDE CHILDREN'S HOSP
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-06-01 至 2026-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10614101
关键词：
Affinity Animals Antibiotic Resistance Antibiotic Therapy Antibiotics Antibodies Bacteria Biological Biological Assay Cessation of life Cholelithiasis Chronic Ciprofloxacin Clinical Trials Communicable Diseases Data Detection Development Disease Dose Drug Kinetics Enteral Enterobacteriaceae Exhibits Future Gallbladder Gastroenteritis Goals Human Immune response In Vitro Individual Infection Intervention Investigation Life Location Maintenance Measures Medical Methods Microbial Biofilms Modeling Molecular Target Monitor Morbidity - disease rate Mus Operative Surgical Procedures Outcome Study Pharmaceutical Chemistry Pharmaceutical Preparations Pharmacology Phenotype Play Process Property Research Resistance Role Safety Salmonella Salmonella typhi Salmonella typhimurium Site Solubility Structure-Activity Relationship Systemic disease Therapeutic Intervention Time Treatment Efficacy Typhoid Fever Work acute infection alternative treatment analog bacterial lysate chronic infection drug discovery effective therapy immune clearance in vivo innovation interest mortality mouse model mutant next generation novel novel therapeutics pathogen prevent small molecule small molecule inhibitor transmission process

项目摘要

Salmonellae are Enterobacteriaceae that cause a spectrum of diseases in humans and animals, including enteric (typhoid) fever and gastroenteritis. Typhoid fever caused primarily by Salmonella enterica serovar Typhi (S. Typhi), results in a life-threatening systemic disease that is responsible for significant morbidity and mortality annually worldwide. Approximately 5% of individuals infected with S. Typhi become chronic carriers with the gallbladder (GB) as the site of persistence. S. Typhi is a human- restricted pathogen, therefore asymptomatic carriers represent a critical reservoir for further spread of disease. We have demonstrated that gallstones (GSs) aid in the development and maintenance of GB carriage in a mouse model (utilizing S. Typhimurium, which causes a typhoid-fever like disease in mice) and in humans, serving as a substrate to which Salmonellae attach and form a protective biofilm. Thus, biofilm formation is a key step in the establishment of carriers. Traditional antibiotic therapies are usually incapable of clearing chronic S. Typhi infections, as the biofilm phenotype renders the bacteria tolerant to the mechanisms of these drugs. Thus, the identification of novel therapeutics capable of targeting S. Typhi biofilms is necessary in order to eliminate chronic carriage and eradicate the disease. Towards this end, our group has identified four small molecules and two antibodies capable of inhibiting and/or disrupting Salmonella biofilms in vitro. We advance two of the small molecules in this proposal, JG-1 and M4, that both inhibit and disrupt biofilms in vitro and reduce GB bacterial numbers in vivo. We hypothesize that the use of these anti-biofilm compounds in conjunction with an antibiotic will more effectively inhibit and disrupt Salmonella biofilms in vivo in our mouse model of chronic carriage when compared to the administration of antibiotic therapy alone. In Aim 1, we will assess the efficacy of these anti-biofilm compounds at preventing and treating chronic infection compared to traditional antibiotics alone by utilizing our established mouse model of typhoidal chronic carriage. We will also measure important pharmacokinetic and tolerability parameters of these compounds. In order to elucidate the mechanisms by which these compounds antagonize Salmonella biofilms, in Aim 2 we will identify the specific bacterial target(s) of each compound by enriching for mutants exhibiting compound resistance and by performing direct pull-downs of targets from bacterial lysates. Structure activity relationships and derivatives with enhanced physiochemical and biological properties will be generated in Aim 3. In summary, we propose an investigation into the safety, efficacy, and mechanisms of novel anti-biofilm compounds to prevent and treat chronic infections by typhoidal Salmonella. To our knowledge this study will be the first attempt (utilizing subject experts in anti-biofilm medicinal chemistry and Salmonella chronic infection) to specifically target Salmonella biofilm formation in vivo as a means of combating chronic carriage.

沙门氏菌是肠杆菌科，引起人类和动物的各种疾病，包括肠（伤寒）发烧和胃肠炎。伤寒发烧主要是由肠道沙门氏菌血清Typhi（S. typhi）引起的，导致一种威胁生命的全身性疾病，该疾病每年都导致全球范围内的显着发病率和死亡率。感染孢子链球菌的个体中约有5％成为胆囊（GB）的慢性携带者，作为持久性的部位。 S. typhi是一种受限制的病原体，因此无症状的载体代表了进一步传播疾病的关键储藏。我们已经证明，胆结石（GSS）有助于小鼠模型中GB运输的开发和维护（利用鼠伤伤了小鼠的鼠伤寒链球菌，在小鼠中引起了疾病）和人类的疾病，作为salmonellae附着并形成保护性生物膜的底物。因此，生物膜的形成是建立载体的关键步骤。传统的抗生素疗法通常无法清除慢性S. typhi感染，因为生物膜表型使细菌耐受这些药物的机制耐受性。因此，必须鉴定能够靶向孢子链球菌生物膜的新型治疗剂，以消除慢性运输和消除疾病。为此，我们的小组已经确定了四个小分子和两种能够在体外抑制和/或破坏沙门氏菌生物膜的抗体。我们在该提案JG-1和M4中推进了两个小分子，它们在体外抑制和破坏生物膜并减少了体内GB细菌数量。我们假设，与单独抗生素治疗相比，在我们的慢性马车小鼠模型中，在体内使用这些抗生物膜化合物与抗生素结合使用。在AIM 1中，我们将通过使用我们已建立的伤寒小鼠慢性携带的小鼠模型来评估这些抗生物膜化合物在预防和治疗慢性感染方面的疗效。我们还将测量这些化合物的重要药代动力学和耐受性参数。为了阐明这些化合物拮抗沙门氏菌生物膜的机制，在AIM 2中，我们将通过富集具有复合耐药性的突变体并从细菌裂解物中执行表现出复合抗性的突变体并直接下拉靶标，来识别每种化合物的特定细菌靶标。在AIM 3中将产生与生理学和生物学特性增强的结构活性关系和衍生物。总而言之，我们提出了对新型抗生物胶体化合物的安全性，功效和机制进行研究，以预防和治疗伤寒沙门氏菌的慢性感染。据我们所知，这项研究将是首次尝试（利用抗生物膜药化学和沙门氏菌慢性感染中的主题专家），以特异性地靶向体内沙门氏菌生物膜形成，以作为对慢性运输的一种手段。