Deciphering the genetic basis of differential antibiotic efficacy in Enterococcus faecalis endocarditis

破译抗生素对粪肠球菌心内膜炎疗效差异的遗传基础

• 批准号: 10597129
• 负责人: Daria N Van Tyne
• 金额: $ 23.85万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10597129
• 关键词: Address; Adoption; Affect; Affinity; Ampicillin; Antibiotics; Attenuated; Bacteremia; Bacterial Genome; Biological; Biological Assay; Carbapenems; Ceftriaxone; Cephalosporins; Clinic; Clinical; Code; Combined Antibiotics; Consensus; Data; Disease; Dominant Genetic Conditions; Dose; Drug Kinetics; Endocarditis; Enterococcus; Enterococcus faecalis; Epidemiology; Exposure to; Failure; Foundations; Future; Genetic; Genome; Genomics; Genotype; Gentamicins; Growth; Guidelines; Hour; In Vitro; Infective endocarditis; International; KAI1 gene; Laboratories; Mediator; Medical center; Mutation; Operative Surgical Procedures; Outcome; Patients; Penicillin Binding Protein 4; Penicillin-Binding Proteins; Pharmacodynamics; Play; Population; Predisposition; Probability; Protein phosphatase; Recurrence; Regimen; Research Project Grants; Role; Sepsis; Testing; Therapeutic; Toxic effect; Translating; Treatment Failure; United States; antimicrobial; beta-Lactam Resistance; beta-Lactams; candidate identification; clinical practice; comorbidity; density; effective therapy; experience; genome sequencing; genomic epidemiology; improved; in vitro activity; in vitro testing; interest; mortality; mutant; older patient; optimal treatments; overexpression; pathogen; personalized approach; pharmacodynamic model; pharmacokinetics and pharmacodynamics; protein phosphatase 2C; synergism; targeted treatment; treatment strategy; Address; Adoption; Affect; Affinity; Ampicillin; Antibiotics; Attenuated; Bacteremia; Bacterial Genome; Biological; Biological Assay; Carbapenems; Ceftriaxone; Cephalosporins; Clinic; Clinical; Code; Combined Antibiotics; Consensus; Data; Disease; Dominant Genetic Conditions; Dose; Drug Kinetics; Endocarditis; Enterococcus; Enterococcus faecalis; Epidemiology; Exposure to; Failure; Foundations; Future; Genetic; Genome; Genomics; Genotype; Gentamicins; Growth; Guidelines; Hour; In Vitro; Infective endocarditis; International; KAI1 gene; Laboratories; Mediator; Medical center; Mutation; Operative Surgical Procedures; Outcome; Patients; Penicillin Binding Protein 4; Penicillin-Binding Proteins; Pharmacodynamics; Play; Population; Predisposition; Probability; Protein phosphatase; Recurrence; Regimen; Research Project Grants; Role; Sepsis; Testing; Therapeutic; Toxic effect; Translating; Treatment Failure; United States; antimicrobial; beta-Lactam Resistance; beta-Lactams; candidate identification; clinical practice; comorbidity; density; effective therapy; experience; genome sequencing; genomic epidemiology; improved; in vitro activity; in vitro testing; interest; mortality; mutant; older patient; optimal treatments; overexpression; pathogen; personalized approach; pharmacodynamic model; pharmacokinetics and pharmacodynamics; protein phosphatase 2C; synergism; targeted treatment; treatment strategy

SUMMARY Enterococcus faecalis causes infective endocarditis (IE), and mortality rates associated with E. faecalis IE are as high as 30%. Treatment for E. faecalis IE has shifted over the last decade from ampicillin and gentamicin (AG) to ampicillin and ceftriaxone (AC), due to prior studies showing equal efficacy and improved tolerance of AC. Despite the rapid adoption of AC in clinical practice, our review of nearly 200 cases of E. faecalis IE at our center over the last decade showed strikingly high mortality rates among patients treated with AC. We investigated the genomic epidemiology of E. faecalis IE at our center since 2018, and found that 36% of all collected isolates belonged to multi-locus sequence types ST6 and ST179. All ST6 isolates harbored a mutation previously associated with overexpression of the low-affinity penicillin-binding protein 4 (PBP4) and increased resistance to beta-lactams, cephalosporins, and carbapenems. We also found that all ST179 isolates possessed a mutation in the coding sequence of PBP4 (P520S), that was previously correlated with lowered beta-lactam affinity. We tested isolates for their susceptibility to AC synergy using checkerboard assays, and observed decreased synergy for ST6 isolates, as well as for an isolate encoding a mutation in the PP2C-type protein phosphatase IreP. Finally, we tested how effectively AC could kill E. faecalis using a one-compartment pharmacokinetic-pharmacodynamic (PK-PD) model of AC tolerance, and found that ST6 and ST179 isolates were able to regrow after 24-48 hours of AC exposure, while an unrelated isolate with a wild type PBP4 sequence showed no regrowth. Here we propose to test the hypothesis that E. faecalis causing IE encode genetic features that cause diminished AC synergy and that may lead to treatment failure in some patients. We propose to first investigate the genomic epidemiology of E. faecalis IE in the United States, and to identify E. faecalis mutations that are associated with diminished AC synergy in vitro. Then, we will evaluate the pharmacodynamics of AC against genetically diverse E. faecalis IE isolates, and will test alternative antibiotic combinations against isolates with reduced susceptibility to AC synergy. The practice change from AG to AC has been made without knowing how genetically diverse E. faecalis respond to AC, and our preliminary data suggest that this change may not be benefiting all patients. There is an urgent need to determine whether the E. faecalis IE treatment paradigm requires revision, and if so, which alternative combinations are likely to be most effective. Our early findings indicate that not all E. faecalis IE isolates respond equally well to AC, and a more individualized approach that incorporates bacterial genotypes and tailored antibiotic combinations may be required. Enabled by compelling preliminary data, the proposed study will integrate epidemiologic, genomic, and PK-PD approaches to address these important questions. The results will lay the foundation for future studies to validate optimal treatment strategies for enterococcal IE, and to translate these treatments into the clinic.

概括 粪肠球菌引起感染性心内膜炎（IE），与粪肠球菌相关的死亡率IE是 高达30％。 E. faecalis IE的治疗已从氨苄西林和庆大霉素转移了 （AG）到氨苄青霉素和头孢曲松（AC），因为先前的研究表明效果相等，并且提高了耐受性 交流。尽管AC在临床实践中迅速采用，但我们对近200例粪肠球菌的审查IE 在过去十年中，中心表现出AC治疗的患者的死亡率惊人。我们 自2018年以来，研究了我们中心的E. faecalis IE的基因组流行病学，发现其中36％ 收集的分离株属于多分裂序列类型ST6和ST179。所有ST6隔离都具有突变 以前与低亲和力青霉素结合蛋白4（PBP4）的过表达相关并增加 对β-内酰胺，头孢菌素和碳青霉烯的抗性。我们还发现所有ST179分离株都拥有 PBP4（p520）的编码序列中的突变，该突变与以前与降低的β-内酰胺相关 亲和力。我们测试了分离株使用棋盘测定的分离株对AC协同作用的敏感性，并观察到 ST6分离株以及编码PP2C型蛋白突变的分离物的协同作用降低 磷酸酶IREP。最后，我们测试了AC可以使用一个校区有效地杀死E.粪便的AC AC耐受性的药代动力学 - 药效学（PK-PD）模型，发现ST6和ST179分离株 24-48小时的交流电暴露后能够再生，而无关的分离物具有野生型PBP4序列 显示没有再生。在这里，我们建议测试引起IE的粪肠球菌编码遗传特征的假设 这会导致AC协同作用减少，并可能导致某些患者的治疗失败。我们建议先 研究美国粪肠球菌IE的基因组流行病学，并鉴定粪肠球菌突变 与体外AC协同作用减少有关。然后，我们将评估AC的药效学 针对遗传多样的粪肠球菌IE分离株，并将测试针对分离株的替代性抗生素组合 对AC协同作用的敏感性降低。从AG到AC的做法已经不知所措 遗传多种多样的E.粪便对AC的反应，我们的初步数据表明，这种变化可能不会 使所有患者受益。迫切需要确定粪肠球菌IE治疗范式是否 需要修订，如果是这样，哪种替代组合可能最有效。我们的早期发现 表明并非所有的粪肠球菌IE分离物对AC的反应都很好，并且是一种更个性化的方法 可能需要结合细菌基因型和量身定制的抗生素组合。通过引人注目启用 初步数据，拟议的研究将整合流行病学，基因组和PK-PD方法，以解决 这些重要的问题。结果将为将来的研究奠定基础，以验证最佳治疗 肠球菌IE的策略，并将这些治疗方法转化为诊所。