Identifying breath biomarkers for S. aureus methicillin resistance and small colony variants

识别金黄色葡萄球菌甲氧西林耐药性和小菌落变异的呼吸生物标志物

• 批准号: 10379289
• 负责人: HEATHER DENISE BEAN
• 金额: $ 37.76万
• 依托单位: ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10379289
• 关键词: Biological Markers; Breath Tests; Bronchoalveolar Lavage; Caring; Cause of Death; Child; Chronic; Clinical Research; Collection; Culture-independent methods; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Data; Detection; Diagnosis; Disease Progression; Etiology; Face; Goals; Human; In Vitro; Infection; Link; Lung infections; Measures; Metagenomics; Methicillin; Methicillin Resistance; Methods; Outcome; Patient-Focused Outcomes; Patients; Persons; Phenotype; Play; Population; Predictive Value; Production; Pseudomonas aeruginosa; Pulmonary Cystic Fibrosis; Pulmonary Inflammation; Research; Respiratory Failure; Respiratory Tract Infections; Risk; Role; Sampling; Sensitivity and Specificity; Shotguns; Specimen; Sputum; Staphylococcus aureus; Staphylococcus aureus infection; Techniques; Testing; Thymidine; Variant; base; bean; biomarker panel; children with cystic fibrosis; clinically relevant; co-infection; cystic fibrosis patients; design; detection test; diagnostic accuracy; diagnostic tool; effective therapy; high risk; improved; in vivo; infection rate; lung pathogen; metabolome; methicillin resistant Staphylococcus aureus; microbial; mortality; mortality risk; mouse model; noninvasive diagnosis; novel; oropharyngeal swab; prospective; pulmonary function; pulmonary function decline; rapid detection; recruit; standard of care

PROJECT ABSTRACT: A primary cause of death for most persons with cystic fibrosis (CF) is respiratory failure caused by damaging chronic lung infections and inflammation. Staphylococcus aureus is the most common cause of lung infections in the US CF population, with 70% of patients testing positive for S. aureus in 2018. There are two subtypes of S. aureus that are particularly worrying because they are linked to lower lung function and higher risk of death: methicillin-resistant S. aureus (or MRSA) and small colony variants (or SCVs). Approximately 50% of CF patients test positive for MRSA and 28% test positive for SCVs. Testing for S. aureus, MRSA, and SCVs heavily relies upon the collection of sputum, but as CF care improves and use of CFTR modulators increases, the production of sputum is declining, though the risk of lung infections persists. Therefore, novel methods for diagnosing lung infections without sputum are urgently needed. Our long-term goal is to develop a breath test for the detection of S. aureus MRSA and SCV in chronic CF lung infections. The overall objective of this proposal is to identify putative breath biomarkers of MRSA and SCVs and to determine their diagnostic accuracy. Our central hypothesis is that volatile biomarkers in breath can be used to rapidly and sensitively detect MRSA and SCVs, independent of co-infections with other species, or the presence of other S. aureus isolates. We will test our hypothesis by leveraging well- characterized S. aureus isolates from the Small Colony Variant S. aureus (SCVSA) study (Aim 1), and paired sputum and breath specimens from the IMproving P. Aeruginosa deteCTion using Breath (IMPACT-Breath) study (Aim 2). The expected outcomes of this project are breath biomarkers of S. aureus MRSA and SCVs, and estimates of their sensitivity and specificity in the breath of persons with CF. Aim 1: Identify putative volatile biomarkers of MRSA, SCVs, and MRSA-SCVs grown in vitro. We will characterize the volatile metabolomes of methicillin sensitive-normal colony variant (MSSA-NCV), MRSA- NCV, MSSA-SCV, and MRSA-SCV isolates cultured in vitro, utilizing 100 sequenced and phenotyped isolates from the SCVSA study. We hypothesize that there are distinct volatile biomarkers for MRSA vs. MSSA and for SCV vs. NCV isolates, and that a novel set of biomarkers are produced by MRSA-SCV isolates. Aim 2: Refine putative volatile biomarkers of MRSA and SCV and estimate their accuracy in the breath of persons with CF. We will analyze paired sputum and breath samples from 100 S. aureus positive CF lung infections from the IMPACT-Breath study. We will use culture-dependent and culture-independent methods to identify and quantify MRSA and SCVs in the sputum and correlate these data to each subject’s breath volatiles. We hypothesize that volatile biomarkers for MRSA and SCV will be detected in the breath of persons that are culture-positive for these S. aureus subtypes, even in the presence of other microbial species, and in the presence of MSSA and NCVs.

项目摘要：大多数囊性纤维化 (CF) 患者死亡的主要原因是呼吸系统疾病 慢性肺部感染和炎症造成的破坏性衰竭。金黄色葡萄球菌是最多的 美国 CF 人群肺部感染的常见原因，70% 的患者金黄色葡萄球菌检测呈阳性 2018 年。金黄色葡萄球菌有两种亚型特别令人担忧，因为它们与较低的 肺功能和死亡风险较高：耐甲氧西林金黄色葡萄球菌（或 MRSA）和小菌落变种（或 SCV）。大约 50% 的 CF 患者 MRSA 检测呈阳性，28% 的 SCV 检测呈阳性。测试 金黄色葡萄球菌、MRSA 和 SCV 在很大程度上依赖于痰液的收集，但随着 CF 护理的改进和使用 CFTR 调节剂的数量增加，痰液产生量减少，但肺部感染的风险增加 持续存在。因此，迫切需要无需痰液即可诊断肺部感染的新方法。 我们的长期目标是开发一种呼气测试来检测慢性 CF 中的金黄色葡萄球菌 MRSA 和 SCV 肺部感染。该提案的总体目标是确定 MRSA 和 MRSA 的假定呼吸生物标志物 SCV 并确定其诊断准确性。我们的中心假设是呼吸中的挥发性生物标志物 可用于快速、灵敏地检测 MRSA 和 SCV，而不受与其他病毒的共同感染的影响 种，或其他金黄色葡萄球菌分离株的存在。我们将通过充分利用来检验我们的假设 从小菌落变种金黄色葡萄球菌 (SCVSA) 研究（目标 1）中分离出金黄色葡萄球菌，并将其配对 使用呼吸改进铜绿假单胞菌检测 (IMPACT-Breath) 的痰液和呼吸样本 研究（目标 2）。该项目的预期成果是金黄色葡萄球菌 MRSA 和 SCV 的呼吸生物标志物， 以及对 CF 患者呼吸的敏感性和特异性的估计。 目标 1：鉴定体外培养的 MRSA、SCV 和 MRSA-SCV 的假定挥发性生物标志物。我们将 表征甲氧西林敏感正常菌落变异体 (MSSA-NCV)、MRSA- 的挥发性代谢组 利用 100 个已测序和表型分离株在体外培养 NCV、MSSA-SCV 和 MRSA-SCV 分离株 来自 SCVSA 研究。我们假设 MRSA 与 MSSA 存在不同的挥发性生物标志物，并且 SCV 与 NCV 分离株的比较，并且 MRSA-SCV 分离株产生了一组新的生物标志物。 目标 2：提炼 MRSA 和 SCV 的假定挥发性生物标志物并估计其在呼吸中的准确性 患有 CF 的人。我们将分析来自 100 个金黄色葡萄球菌阳性 CF 肺的配对痰液和呼吸样本 IMPACT-Breath 研究中的感染。我们将使用依赖于文化和独立于文化的方法 识别和量化痰中的 MRSA 和 SCV，并将这些数据与每个受试者的呼吸相关联 挥发物。我们假设将在人的呼吸中检测到 MRSA 和 SCV 的挥发性生物标志物 即使存在其他微生物物种，这些金黄色葡萄球菌亚型也呈培养阳性，并且 MSSA 和 NCV 的存在。