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: 10590672
• 负责人: HEATHER DENISE BEAN
• 金额: $ 37.97万
• 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/10590672
• 关键词: Biological Markers; Breath Tests; Bronchoalveolar Lavage; Caring; Cause of Death; Child; Chronic; Classification; Clinical Research; Collection; Culture-independent methods; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Data; Data Correlations; Detection; Diagnosis; Disease Progression; Etiology; Face; Goals; Human; In Vitro; Infection; Link; Lung infections; Measures; Metagenomics; Methicillin; Methicillin Resistance; Methods; Non-Invasive Detection; Outcome; Patient-Focused Outcomes; Patients; Persons; Phenotype; Play; Population; Predictive Value; Predisposition; Production; Pseudomonas aeruginosa; Pulmonary Cystic Fibrosis; Pulmonary Inflammation; Research; Resistance to infection; Respiratory Failure; Respiratory Tract Infections; Risk; Role; Sampling; Sensitivity and Specificity; Shotguns; Specimen; Sputum; Staphylococcus aureus; Staphylococcus aureus infection; Techniques; Testing; Thymidine; Variant; Volatilization; 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; 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：大多数囊性纤维化患者的主要死亡原因是呼吸系统疾病。 由破坏性的慢性肺部感染和炎症引起的衰竭。金黄色葡萄球菌是最多的 美国慢性肺病患者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。有两种金黄色葡萄球菌亚型特别令人担忧，因为它们与较低的 肺功能和更高的死亡风险：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%的患者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的收集，但随着CF护理的改进和使用 Cftr调节剂的增加，痰的产生正在下降，尽管肺部感染的风险 坚持不懈。因此，迫切需要新的无痰肺部感染的诊断方法。 我们的长期目标是开发一种呼气试验来检测慢性CF患者的金黄色葡萄球菌MRSA和SCV 肺部感染。该提案的总体目标是确定MRSA和MSA的呼吸生物标志物。 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 物种，或其他金黄色葡萄球菌分离株的存在。我们将通过良好的杠杆作用来检验我们的假设- 小群体变异金黄色葡萄球菌(SCVSA)研究(AIM 1)的特征金黄色葡萄球菌分离株，并配对 利用呼气(Impact-Breath)改进的铜绿假单胞菌检测的痰和呼气样本 研究(目标2)。该项目的预期结果是金黄色葡萄球菌MRSA和SCV的呼气生物标志物， 并评估其在CF患者呼吸中的敏感性和特异性。 目的1：鉴定体外培养的MRSA、SCV和MRSA-SCV的挥发性生物标志物。我们会 甲氧西林敏感-正常菌落变异株(MSSA-NCV)的挥发性代谢产物的特征 NCV、MSSA-SCV和MRSA-SCV分离株的体外培养，利用100个测序和表型分离株 来自SCVSA的研究。我们假设MRSA和MSSA之间存在不同的挥发性生物标志物 对于SCV和NCV分离物，MRSA-SCV分离物产生了一组新的生物标志物。 目的2：提纯MRSA和SCV可能的挥发性生物标志物，并评估其在呼吸中的准确性 患有慢性萎缩性脑病的人我们将分析100个金黄色葡萄球菌阳性的CF肺的痰和呼气样本 来自IMPACT呼吸研究的感染。我们将使用文化依赖和文化独立的方法 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。我们假设在人的呼吸中会检测到MRSA和SCV的挥发性生物标记物 这些金黄色葡萄球菌亚型的培养呈阳性，即使在存在其他微生物物种的情况下，也是如此 MSSA和NCVS的存在。