Identification of novel anti-virulence compounds against Pathogenic Burkholderia

鉴定针对致病性伯克霍尔德氏菌的新型抗毒力化合物

• 批准号: 10374147
• 负责人: Matthew M Schaefers
• 金额: $ 22.13万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-17 至 2023-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10374147
• 关键词: Abscess; Antibiotic Resistance; Antibiotics; Australia; Bacteria; Bacterial Genes; Biological Assay; Bioterrorism; Boston; Burkholderia; Burkholderia Infections; Burkholderia cepacia complex; Burkholderia pseudomallei; Caulobacter; Cell Culture Techniques; Chronic; Clinical; Cystic Fibrosis; Development; Disease; Disease Outbreaks; Effectiveness; Fever; Gene Expression Regulation; Genes; Genetic Variation; Genome; Genomics; Goals; Gram-Negative Bacteria; In Vitro; Infection; Lead; Life; Lung infections; Melioidosis; Membrane; Microbe; Modeling; Mutation; Oxygen; Pathogenesis; Pathogenicity; Pathway interactions; Patients; Pediatric Hospitals; Permeability; Persons; Pneumonia; Pseudomonas aeruginosa; Pseudomonas aeruginosa infection; Publishing; Reporter; Research; Resistance; Rhizobium; Sensory; Sepsis; Soil; Southeastern Asia; Structure; System; Systemic infection; Therapeutic; Therapeutic Agents; Toxic effect; Tropical Climate; Variant; Virulence; Virulent; Water; Work; antimicrobial drug; bacterial genome sequencing; beta-Lactamase; chronic infection; cystic fibrosis patients; efflux pump; healthcare-associated infections; high throughput screening; macrophage; member; mortality; novel; novel therapeutic intervention; novel therapeutics; pathogen; programs; protein-histidine kinase; pulmonary function decline; small molecule libraries; targeted agent; transcription factor

Project Abstract The long-term goal of this project is to develop novel therapeutics for the treatment of the Gram-negative pathogens in the Burkholderia genus which includes the Burkholderia cepacia complex (BCC) and Burkholderia pseudomallei. These pathogens cause serious, chronic lung infections and are also major causes of healthcare-associated infections. Treatment of infections caused by these pathogens is often difficult due to the broad-spectrum antibiotic resistance that is commonly seen. The development of novel therapeutics to treat these pathogens is critically needed. Our published work analyzing the genomic diversity of isolates of the BCC species B. dolosa and B. multivorans collected from people with CF has led to the discovery that the fixL gene appears to be under strong positive selection. FixL has been described in Rhizobium and Caulobacter as a sensory histidine kinase of a two-component system that detects oxygen tension and phosphorylates the transcription factor FixJ under low oxygen conditions. Our previous work has found that the BCC FixLJ system is required for pathogenesis and modulation of this pathway has profound effects of virulence. Interestingly, constructs carrying evolved FixL variants associated with periods of clinical decline in patients were more virulent in multiple infection models compared to isogenic constructs carrying ancestral FixL variants. These more virulent FixL sequences had lower FixLJ activity than less virulent constructs carrying ancestral FixL variants demonstrating that increased FixLJ activity is determinantal to virulence. We hypothesize that we can reduce Burkholderia virulence by activating the FixLJ pathway. By targeting virulence, we predict that the bacteria would no longer be able to infect or persist within the host. In the first aim of this project we will identify compounds that activate FixLJ using a high-throughput screen with a Burkholderia fix pathway reporter strain. In Aim 2 we will evaluate promising lead compounds identified in Aim 1 for their in vitro effectiveness at reducing virulence of multiple Burkholderia species using an in vitro macrophage assay. We also will evaluate the toxicity of lead compounds using cell culture. We plan to identify 3-4 lead compounds with an EC50 in the low micromolar (1-10) range and a toxicity at least 5-fold higher than the EC50. These lead compounds will be further developed into therapies for use to treat Burkholderia infections.

项目摘要