Breath Test for Pseudomonas aeruginosa in CF

CF 中铜绿假单胞菌呼气试验

• 批准号: 7571290
• 负责人: GRAHAM S TIMMINS
• 金额: $ 18.75万
• 依托单位: UNIVERSITY OF NEW MEXICO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-17 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7571290
• 关键词: Age; Animal Model; Antibiotic Therapy; Anus; Bacterial Antibiotic Resistance; Bacterial Infections; Breath Tests; Breathing; Characteristics; Chemicals; Chronic; Clinical; Clinical Trials; Cyanides; Cystic Fibrosis; Data; Detection; Diagnostic; Disease Management; Dosage Forms; Dose; Drug Formulations; Effectiveness; Enzymes; Exhalation; Gene Expression; Glycine; Growth; Helicobacter pylori; Hereditary Disease; High Prevalence; In Vitro; Infection; Inflammatory; Irrigation; Isotopes; Label; Life; Life Expectancy; Lung; Mass Spectrum Analysis; Measures; Metabolic Pathway; Metabolism; Microbial Biofilms; Modality; Modeling; Monitor; Mus; Pathway interactions; Patients; Phase I Clinical Trials; Phenotype; Physiology; Pseudomonas aeruginosa; Research Personnel; Respiratory physiology; Sampling; Specificity; Sputum; Stable Isotope Labeling; Staging; Stomach; System; Testing; Time; Translating; Treatment Protocols; Urea; Urease; Work; denitrification; drinking; enzyme pathway; improved; mucoid; novel; novel diagnostics; outcome forecast; pre-clinical; product development; public health relevance; pulmonary function decline; ratiometric; response; stable isotope; tool; translational clinical trial

DESCRIPTION (provided by applicant): The progressive lung damage in cystic fibrosis (CF) arises from characteristic bacterial colonization with Pseudomonas aeruginosa being central After initial infection then colonization with wild-type strains, conversion of P. aeruginosa to the mucoid phenotype in the CF host occurs, increasing bacterial resistance to antibiotics and inflammatory lung damage, and causing declining pulmonary function and prognosis. There remains an unmet need for rapid, non-invasive diagnostic analysis of lung P. aeruginosa presence, burden and mucoid status. Such a diagnostic would enable real-time monitoring of infection, and also significantly improve CF management, that currently relies upon indirect measures such as lung function and culture of expectorated sputum (that is variable, samples only a part of the lung, not applicable to younger patients) or broncoalveolar lavage (that is invasive and unsuitable for repetitive use). We show that several isotopically labeled substrates can be uniquely converted by P. aeruginosa to volatile exhalable labeled gasses, in ways that depend upon bacterial phenotype. We therefore hypothesize that We can use P. aeruginosa-specific metabolism of stable isotopically-labeled compounds to exhaled gasses to determine lung infection, bacterial load, biofilm growth and mucoid status However, before we move to a translational clinical trial, we need to test our hypothesis, delineate the typical ratios of labeled volatiles in wild-type, biofilm and mucoid strains, and also demonstrate effectiveness in an animal model of CF lung infection with P. aeruginosa. We will therefore perform these aims: Specific Aim 1 Demonstrate and develop use of isotope ratio mass spectrometry to measure isotopically labeled gasses from denitrification, cyanide synthase and urease activities in P. aeruginosa in vitro. Specific Aim 2 Delineate the range of ratios of urease to cyanide synthase/denitrification products for non- mucoid and mucoid P. aeruginosa strains in vitro growing planktonically and in biofilms. Specific Aim 3 Demonstrate effectiveness of this diagnostic approach in mice with mucoid and non-mucoid P. aeruginosa lung infection. Successful completion of this preclinical stage would be followed by formulation work on an inhaled dosage form, and Phase 1 clinical trial. PUBLIC HEALTH RELEVANCE: Cystic fibrosis is a high-prevalence, life shortening genetic disease, with much of the lung damage coming from infection with P. aeruginosa. Yet, the clinical tools to monitor for P. aeruginosa presence, burden & phenotype, so that the infection can be actively and pro-actively managed are not suitable or available. We propose to test the potential of a novel breath test, that relies upon a unique panel of P. aeruginosa metabolic pathways to produce stable isotope labeled gasses from specific substrates. If successful, this work can be translated to provide a sensitive and rapid new diagnostic that could significantly improve management of this disease.

描述（由申请人提供）：囊性纤维化（CF）中的进行性肺损伤由特征性细菌定植引起，铜绿假单胞菌为中心。在初始感染后，然后用野生型菌株定植，在CF宿主中发生铜绿假单胞菌向粘液样表型的转化，增加细菌对抗生素的耐药性和炎性肺损伤，并导致肺功能和预后下降。对于肺铜绿假单胞菌存在、负荷和粘液状态的快速、非侵入性诊断分析仍然存在未满足的需求。这样的诊断将使得能够实时监测感染，并且还显著改善CF管理，目前CF管理依赖于间接测量，诸如肺功能和咳出痰的培养（即可变的，仅对肺的一部分进行采样，不适用于年轻患者）或支气管肺泡灌洗（其是侵入性的并且不适合重复使用）。我们发现，几种同位素标记的底物可以独特的转化由铜绿假单胞菌挥发性呼出标记气体，在依赖于细菌表型的方式。因此，我们假设我们可以使用稳定同位素标记化合物对呼出气体的铜绿假单胞菌特异性代谢来确定肺部感染、细菌负荷、生物膜生长和粘液状态。然而，在我们进行转化临床试验之前，我们需要测试我们的假设，描绘野生型、生物膜和粘液菌株中标记挥发物的典型比率，并且还证明了在用铜绿假单胞菌感染CF肺的动物模型中的有效性。因此，我们将执行这些目标：具体目标1演示和开发同位素比质谱法的使用，以测量同位素标记的气体从脱氮，氰化物合成酶和尿素酶活性在铜绿假单胞菌在体外。具体目标2描述非粘液型和粘液型铜绿假单胞菌菌株在体外培养和生物膜中尿素酶与氰化物合酶/脱氮产物的比例范围。具体目标3证明这种诊断方法在患有粘液和非粘液铜绿假单胞菌肺部感染的小鼠中的有效性。成功完成这一临床前阶段之后，将进行吸入剂型的配制工作和1期临床试验。公共卫生关系：囊性纤维化是一种高患病率、缩短寿命的遗传性疾病，其中大部分肺损伤来自铜绿假单胞菌感染。然而，用于监测铜绿假单胞菌的存在、负荷和表型以使得感染可以被主动和积极地管理的临床工具是不合适的或不可用的。我们建议测试一种新型呼吸测试的潜力，该测试依赖于一组独特的铜绿假单胞菌代谢途径，以从特定底物产生稳定的同位素标记气体。如果成功，这项工作可以转化为提供一种敏感和快速的新诊断方法，可以显着改善这种疾病的管理。