Genetic screen to define the regulation of beta-hemolysin toxin expression in Streptococcus agalactiae

基因筛选以确定无乳链球菌中 β-溶血素毒素表达的调节

• 批准号: 10731405
• 负责人: Natalia Korotkova
• 金额: $ 19.13万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-19 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10731405
• 关键词: Abbreviations; Adult; Agar; Antibiotic Prophylaxis; Antibiotic Resistance; Bacteria; Binding; Blood; Blood - brain barrier anatomy; Blood Circulation; Cell Separation; Central Nervous System; Chemicals; Colon; Culture Media; Cytolysins; Detection; Development; Disease; Endothelium; Environment; Epithelium; Family; Folic Acid; Gene Expression; Genes; Genetic Screening; Genetic Transcription; Goals; Gram-Positive Bacteria; Hemolysin; Human; Immune; Immune Evasion; Immunocompromised Host; Induction of Apoptosis; Infection; Invaded; Libraries; Lipids; Meningitis; Mothers; Neonatal meningitis; Newborn Infant; Niacinamide; Nutrient; Oligopeptides; Pathway interactions; Peptide Sequence Determination; Peptides; Phagocytes; Phagocytosis Induction; Pigments; Pregnant Women; Preventive measure; Production; Proteins; Regulation; Repression; Research; Sepsis; Sequence Determination; Serum; Signal Transduction; Small Intestines; Starch; Streptococcal Infections; Streptococcus Group B; System; Testing; Therapeutic; Toxin; Vaccines; Virulence; Virulence Factors; Water; Work; blood-brain barrier disruption; clinically relevant; gastrointestinal; genomic locus; gut microbiota; in vivo; inhibitor; inorganic phosphate; intestinal epithelium; metabolomics; microbiome; microbiota; microorganism; mutant; neonatal sepsis; novel; novel therapeutics; older patient; pathogen; placental membrane; prevent; quorum sensing; screening; small molecule; transcriptome sequencing; transmission process; treatment group; vaginal microbiota

Group B Streptococcus (GBS) is a normal constituent of the intestinal and vaginal flora in 15–30% of healthy adults. The bacterium can, however, cause infections in elderly and immunocompromised patients, and pregnant women, and is the main cause of fatal invasive disease in newborns. GBS translocation through epithelial, endothelial, and placental barriers is facilitated by a pore-forming toxin β-hemolysin, also known as the β-hemolytic pigmented lipid or granadaene. To identify factors involved in the regulation of β-hemolysin expression we developed new peptide-free culture media for screening of a transposon mutant library of GBS CJB111. The pilot screens identified nine novel genetic loci associated with positive and negative modulation of β-hemolysin expression. Based on preliminary findings, we hypothesize that GBS possesses a regulatory mechanism that tailors β-hemolysin expression to the environment. To unravel the mechanism, we will employ transposon mutant library screening, RNA-seq and metabolomics analyses, isolation, and de novo sequence determination of secreted peptide-based repressors. The results of this exploratory work have the potential to lead to the development of a novel inhibitor of the invasion state of GBS.

B族链球菌（GBS）是肠道和阴道植物群的正常组成部分 15-30%的健康成年人。然而，这种细菌会导致老年人感染， 免疫功能低下的患者和孕妇，是致命的侵入性的主要原因， 新生儿的疾病GBS通过上皮、内皮和胎盘屏障的易位是 由成孔毒素β-溶血素（也称为β-溶血色素脂质）促进 或granadaene。为了确定β-溶血素表达调控的相关因素，我们 开发了一种新的无肽培养基，用于筛选GBS转座子突变体库 CJB 111.初步筛选确定了9个与阳性和阴性相关的新遗传基因座， β-溶血素表达的负调节。基于初步的发现，我们假设 GBS具有调节机制，使β-溶血素的表达适应于 环境为了阐明其机制，我们将采用转座子突变库筛选， RNA-seq和代谢组学分析、分离和从头序列测定 分泌的基于肽的阻遏物。这项探索性工作的结果有可能 导致GBS侵袭状态的新型抑制剂的开发。