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: 10182986
• 负责人: HEATHER DENISE BEAN
• 金额: $ 40.34万
• 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/10182986
• 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; Diagnostic; Disease Progression; Etiology; Face; Goals; Human; In Vitro; Infection; Link; Lung Inflammation; 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; 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; effective therapy; high risk; improved; in vivo; infection rate; 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; respiratory pathogen; standard of care; tool

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（CF）的死亡原因是呼吸道 损害慢性肺部感染和感染引起的失败。金黄色葡萄球菌是最大的 美国CF人群中肺部感染的常见原因，有70％的患者测试金黄色葡萄球菌阳性 2018年。金黄色葡萄球菌的两个亚型特别令人担忧，因为它们与较低的 肺功能和更高的死亡风险：耐甲氧西林的金黄色葡萄球菌（或MRSA）和小菌落变体（或 SCV）。大约50％的CF患者测试了MRSA阳性，SCV的28％测试阳性。测试 S.金黄色葡萄球菌，MRSA和SCV在很大程度上依赖痰液的收集，但是随着CF护理的改善和使用 CFTR调节剂的增加，痰液的产生正在下降，尽管肺部感染的风险 坚持。因此，迫切需要新的无需痰液肺部感染的肺部感染方法。 我们的长期目标是为慢性CF中的Aureus MRSA和SCV检测开发呼气测试 肺部感染。该提案的总体目的是确定MRSA和 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 可用于快速和敏感地检测MRSA和SCV，与其他共同感染无关 物种，或其他金黄色葡萄球菌分离株的存在。我们将通过利用良好的良好来检验我们的假设 从小菌群变体S.金黄色葡萄球菌（SCVSA）研究（AIM 1）中表征了金黄色葡萄球菌分离株，并配对 痰液和呼吸标本可从呼吸（撞击呼吸）改善铜绿假单胞菌检测 研究（目标2）。该项目的预期结果是Aureus MRSA和SCVS的呼吸生物标志物， 以及估计他们在CF呼吸中的敏感性和特异性。 AIM 1：确定MRSA，SCV和MRSA-SCV的假定挥发性生物标志物在体外生长。我们将 表征甲氧西林敏感正常菌落变体（MSSA-NCV）的挥发性代谢组，MRSA- 在体外培养的NCV，MSSA-SCV和MRSA-SCV分离物，利用100个测序和表型分离株 来自SCVSA研究。我们假设MRSA与MSSA和MSSA和 对于SCV与NCV分离株，并且MRSA-SCV分离株产生了一组新型的生物标志物。 AIM 2：MRSA和SCV的提炼假定的挥发性生物标志物，并估算其呼吸的准确性 有CF的人我们将分析来自100 S.金黄色股票阳性CF肺的配对痰液和呼吸样品 影响 - 呼吸研究的感染。我们将使用依赖文化和文化独立的方法 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。我们假设将在人们的呼吸中检测到MRSA和SCV的挥发性生物标志物 对于这些金黄色葡萄球菌亚型，即使存在其他微生物物种，也是 MSSA和NCV的存在。