Development of adjunctive therapies directed at S. aureus amidases

针对金黄色葡萄球菌酰胺酶的辅助疗法的开发

基本信息

批准号：
8702797
负责人：
BLAISE R BOLES
金额：
$ 0.38万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-03-01 至 2014-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8702797
关键词：
Address Amidohydrolases Animal Model Antibiotic Resistance Antibiotic Therapy Antibiotics Antimicrobial Resistance Bacteria Bacterial Infections Biochemical Biological Assay Biology Blood Cell Wall Cells Chemicals Cleaved cell Communicable Diseases Communities Data Development Drug Formulations Drug resistance Endocarditis Enzymes Fluorescence Resonance Energy Transfer Foundations Frequencies Funding Fusidic Acid Future Generations Genetic Genomics Genus staphylococcus Goals Gram-Positive Bacteria Growth Health Health Care Costs Human Implant In Vitro Infection Lead Libraries Life Mediating Medical Device Michigan Microbial Biofilms Mission Modeling Morbidity - disease rate Names Organism Osteomyelitis Peptides Peptidoglycan Phase Positioning Attribute Prevalence Research Resistance Resources Staphylococcus aureus Structure-Activity Relationship Surface Swimming System Testing Therapeutic Therapeutic Studies Time Tissues Toxic effect Translating United States National Institutes of Health Universities Validation Work amidase antimicrobial chemotherapy clinical application crosslink design drug resistant bacteria enzyme activity experience high throughput screening improved in vivo in vivo Model inhibitor/antagonist member methicillin resistant Staphylococcus aureus mortality mutant novel novel strategies novel therapeutics pathogen prevent public health relevance screening small molecule therapeutic target

项目摘要

Project Summary/Abstract Resistance to antimicrobial chemotherapies is a major contributor to morbidity, mortality, and rising healthcare costs. The prevalence of drug-resistant pathogens against conventional antibiotics has been rising over the last several decades. Of great concern is methicillin-resistant Staphylococcus aureus (MRSA), which is rapidly diminishing the available treatment options for S. aureus infections. As drug resistances continue to emerge there is an urgent need to develop alternative therapeutic approaches such as the development of adjunctive therapies to potentiate the activity of existing antimicrobials. Recently we have discovered that amidase activity of cell wall modifying enzymes (named SsaA1 and SsaA2) mediates S. aureus biofilm resistance to the conventional antibiotic fusidic acid. That is, genetic inactivation of ssaA1 or ssaA2 results in sensitivity of biofilms to fusidic acid. This result suggests that small molecules capable of inhibiting SsaA amidase activity could be used as an adjunctive in conjunction with fusidic acid to effectively eliminate S. aureus biofilms. Mutants in ssaA1 also displayed reduced frequency of fusidic acid resistance emergence, suggesting that in addition to rendering biofilm bacteria sensitive to an antimicrobial, small molecule SsaA amidase inhibitors would also reduce the emergence of drug resistant bacteria. SsaA amidases are an ideal target for small molecule therapies because they are located on the outside of cells making them readily accessible and because humans lack peptidoglycan and the associated biosynthetic machinery (including SsaA amidase homologous). The primary goal of this R21 research is to identify chemical inhibitors of SsaA amidase activity and characterize these molecules for use as potential adjunctive theraputics. To achieve the goal, we propose the following aims: (1) Identify chemical compounds that eliminate SsaA amidase activity via high throughput screening and (2) Elucidate the ability of SsaA chemical inhibitors to sensitize Staphylococcus biofilms to antimicrobial treatment in in vitro and in vivo models of biofilm development. During the next phase of research (R33), we plan on translating our basic findings for clinical applications by investigating chemical optimization of lead compounds, characterizing antimicrobial activity against other gram-positive pathogens, and developing formulation/delivery systems to be tested with in vivo animal models. The PI's experience in S. aureus biology and the strength of the University of Michigan's Center for Chemical Genomics uniquely position us to conduct this research and make profound discoveries.

项目概要/摘要对抗菌化学疗法的耐药性是发病率、死亡率和医疗保健不断提高的主要原因成本。近年来，对传统抗生素产生耐药性的病原体的流行率一直在上升过去几十年。令人高度关注的是耐甲氧西林金黄色葡萄球菌（MRSA），它正在迅速蔓延减少金黄色葡萄球菌感染的可用治疗选择。随着耐药性不断出现迫切需要开发替代治疗方法，例如开发辅助疗法增强现有抗菌药物活性的疗法。最近我们发现酰胺酶活性细胞壁修饰酶（称为 SsaA1 和 SsaA2）介导金黄色葡萄球菌生物膜对常规抗生素夫西地酸。也就是说，ssaA1 或 ssaA2 的基因失活会导致敏感性生物膜转化为夫西地酸。该结果表明能够抑制 SsaA 酰胺酶活性的小分子可作为佐剂与夫西地酸联合使用，有效消除金黄色葡萄球菌生物膜。 ssaA1 突变体也表现出夫西地酸抗性出现频率降低，这表明在除了使生物膜细菌对抗菌小分子 SsaA 酰胺酶抑制剂敏感之外也将减少耐药细菌的出现。 SsaA 酰胺酶是小型药物的理想靶标分子疗法，因为它们位于细胞的外部，使它们易于接近和因为人类缺乏肽聚糖和相关的生物合成机制（包括 SsaA 酰胺酶同源）。这项 R21 研究的主要目标是鉴定 SsaA 酰胺酶活性的化学抑制剂并对这些分子进行表征，以用作潜在的辅助治疗药物。为了实现这一目标，我们建议目标如下： (1) 鉴定通过高通量消除 SsaA 酰胺酶活性的化合物筛选和 (2) 阐明 SsaA 化学抑制剂使葡萄球菌生物膜敏感的能力生物膜发育的体外和体内模型中的抗菌治疗。在下一阶段的研究中（R33），我们计划通过研究化学优化将我们的基本发现转化为临床应用先导化合物，表征对其他革兰氏阳性病原体的抗菌活性，并开发将用体内动物模型测试制剂/递送系统。 PI 在金黄色葡萄球菌生物学方面的经验密歇根大学化学基因组学中心的实力使我们能够进行独特的研究这项研究并取得深刻的发现。