Rapid identification and antibiotic susceptibility testing of sepsis pathogens

脓毒症病原菌的快速鉴定及药敏检测

• 批准号: 9133808
• 负责人: DAVID A HAAKE
• 金额: $ 22.2万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9133808
• 关键词: Acute myocardial infarction; Agar; Antibiotic Resistance; Antibiotic Therapy; Antibiotic susceptibility; Antibiotics; Antimicrobial susceptibility; Bacteremia; Bacteria; Biological Assay; Blinded; Blood; Blood Circulation; Blood Tests; Cause of Death; Ciprofloxacin; Clinical; Clinical Microbiology; Clinical Research; Clinical Trials; Data; Diagnosis; Drops; Escherichia coli; Goals; Growth; Health; Horseradish Peroxidase; Hospitalization; Laboratories; Link; Mainstreaming; Measurement; Measures; Methods; Monobactams; Outcome; Patient Care; Patients; Phase; Predisposition; Research; Research Personnel; Research Proposals; Ribosomal RNA; Sepsis; Signal Transduction; Specificity; Specimen; Staging; Surface; System; Temperature; Test Result; Testing; Time; United States; Urinary tract infection; Urine; cost; detector; effective therapy; falls; innovation; killings; pathogen; prospective; rRNA Precursor; response; sensor

DESCRIPTION (provided by applicant): The key to effective treatment of sepsis is rapid identification and antibiotic susceptibility testing of bloodstream pathogens. Our laboratory has developed an innovative electrochemical sensor assay for rapid (d30 min) genotypic identification of bacterial pathogens, which has been validated independently. The electrochemical sensor assay involves "sandwich" hybridization of bacterial rRNA to species-specific capture and detector probes. Capture probes are used to anchor target rRNA molecules to the surface of electrochemical sensors, while the detector probes generate the electrochemical signal through their link to horseradish peroxidase. Our sensor assay can be performed at room temperature and has the sensitivity to detect as few as 100 bacteria/ml. Proof of concept has been demonstrated in a clinical study of urine specimens from patients with urinary tract infection. Recently, we demonstrated that the electrochemical sensor assay can be employed to rapidly determine antimicrobial susceptibility through measurement of precursor rRNA (pre-rRNA). Because pre-rRNA is a labile, intermediate stage in the formation of mature rRNA, pre-rRNA levels respond rapidly to growth inhibition by antibiotics. Mature rRNA levels fall relatively slowly in response to antibiotics, but pre-rRNA levels drop by >10-fold within 15 min after exposure of susceptible E. coli to ciprofloxacin. More recently, we have found similar responses of bacteria to beta-lactam antibiotics. We believe that this approach can provide actionable information about bloodstream pathogens in the time frame needed to make informed decisions about antibiotic therapy. The goal of this research application is to develop a Rapid Bacterial Identification and Susceptibility (RBIS) Testing System with a time from acquisition of a positive blood culture to bacterial identification of d30 minutes and antimicrobia susceptibility testing results in d60 minutes. The Research Plan has two Specific Aims. In Specific Aim 1 we will determine whether early changes in pre-rRNA levels accurately predict antibiotic susceptibility. In Specific Aim 2 we will perform a clinical study of blinded positive blood cultures to determine the accuracy of our approach. These studies are required to generate preliminary data for a subsequent clinical trial to measure the impact of RBIS Testing System on clinical outcomes and patient care costs.

描述（申请人提供）：有效治疗脓毒症的关键是血流病原体的快速识别和抗生素敏感性测试。我们的实验室开发了一种创新的电化学传感器测定法，用于快速（d30 分钟）细菌病原体的基因型鉴定，该测定法已经过独立验证。电化学传感器测定涉及细菌 rRNA 与物种特异性捕获和检测探针的“三明治”杂交。捕获探针用于将目标 rRNA 分子锚定到电化学传感器的表面，而检测探针则通过与辣根过氧化物酶的连接产生电化学信号。我们的传感器检测可在室温下进行，灵敏度可检测低至 100 个细菌/ml。对尿路感染患者尿液样本的临床研究已经证明了这一概念。最近，我们证明电化学传感器测定可用于通过测量前体 rRNA (pre-rRNA) 来快速确定抗菌敏感性。由于前 rRNA 是成熟 rRNA 形成过程中不稳定的中间阶段，前 rRNA 水平对抗生素的生长抑制反应迅速。成熟 rRNA 水平对抗生素的反应下降相对缓慢，但前 rRNA 水平下降超过 10 倍 敏感大肠杆菌接触环丙沙星后 15 分钟内。最近，我们发现细菌对 β-内酰胺抗生素有类似的反应。我们相信，这种方法可以在做出有关抗生素治疗的明智决策所需的时间范围内提供有关血流病原体的可操作信息。本研究应用的目标是开发一种快速细菌鉴定和药敏（RBIS）测试系统，从获得阳性血培养物到细菌鉴定的时间为 d30 分钟，抗菌药敏测试结果为 d60 分钟。该研究计划有两个具体目标。在具体目标 1 中，我们将确定 pre-rRNA 水平的早期变化是否能准确预测抗生素敏感性。在具体目标 2 中，我们将对阳性血培养物进行盲法临床研究，以确定我们方法的准确性。这些研究需要为后续临床试验生成初步数据，以衡量 RBIS 测试系统对临床结果和患者护理成本的影响。