Pseudomonas Aeruginosa Early CF Adaptive Changes: A Translational Study

铜绿假单胞菌早期 CF 适应性变化：一项转化研究

• 批准号: 8403705
• 负责人: Lucas R Hoffman
• 金额: $ 10.01万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-21 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8403705
• 关键词: Addendum; Address; Age; Ancillary Study; Antibiotic Resistance; Antibiotic Therapy; Antibiotic susceptibility; Antibiotics; Bacteria; Caucasians; Caucasoid Race; Characteristics; Child; Chronic; Clinical; Clinical Data; Clinical Research; Clinical Trials; Cohort Studies; Color; Cystic Fibrosis; Data; Databases; Development; Disease; Disease Progression; Enrollment; Environment; Epidemiology; Functional disorder; Funding; Genes; Goals; Gram-Negative Bacteria; Growth; Height; Hereditary Disease; Hospitalization; In Vitro; Infection; Inflammatory Response; Intervention; Lactamase; Lead; Life; Life Expectancy; Link; Liquid substance; Longevity; Longitudinal Studies; Lung; Lung diseases; Measures; Mentorship; Metabolic; Methods; Microbiology; Mutation; Natural History; Nitrates; Observational Study; Outcome; Patients; Phenotype; Physicians; Pigments; Population; Prevalence; Production; Pseudomonas aeruginosa; Pulmonary Cystic Fibrosis; Quality of life; Regimen; Research; Research Training; Respiratory System; Respiratory physiology; Respiratory tract structure; Risk Factors; Role; Subgroup; Testing; Therapeutic; Time; Training; Translational Research; Weight; advanced disease; career; cell motility; children with cystic fibrosis; clinically relevant; cohort; cystic fibrosis airway; cystic fibrosis patients; early cystic fibrosis; follow-up; inhibitor/antagonist; microbial; mutant; novel; pathogen; prevent; prospective; public health relevance; respiratory; translational study

DESCRIPTION (provided by applicant): Lung disease is the primary determinant of life expectancy and quality of life among people with the genetic disease cystic fibrosis (CF). The opportunistic Gram-negative bacterium Pseudomonas aeruginosa infects the respiratory tracts of most patients with CF, and infection with this pathogen is clearly associated with worse respiratory outcomes. P. aeruginosa infects CF airways early in life. Over many years, bacteria adapt to the CF airway environment and stimulate inflammatory responses that are ineffective in eradicating the infection, yet damage airways. The development of strategies to prevent P. aeruginosa colonization and eliminate chronic infection will require an understanding of the natural history of the bacterial contribution to CF lung disease. This proposal describes a four-year plan to further establish the independent, translational research career for the candidate. In particular, the candidate, a trained physician and microbiologist, will continue his clinical research training and focus his time on his funded, collaborative project to define the natural history of P. aeruginosa changes during early CF airway infection. This project uses the P. aeruginosa clinical isolates, linked clinical data, and unique clinical research mentorship opportunities available from two locally-led, national studies of CF microbiology, the Early Antipseudomonal Therapy in Cystic Fibrosis studies (EPIC). Specifically, this project will define the clinical relevance of infection with P. aeruginosa carrying a newly-identified adaptive change: inactivating mutation in the gene encoding the major transcriptional regulator LasR. This mutation was associated in our preliminary studies with accelerated lung function decline. Perhaps related to this finding, preliminary evidence suggests that LasR mutation leads to increased resistance to the antibiotics used most often in CF therapy. Conversely, LasR mutants are more susceptible in vitro to at least two classes of metabolic inhibitors, suggesting alternative therapeutic strategies for patients infected with these isolates. Thus, the emergence of LasR mutation during chronic P. aeruginosa CF airway infections may serve as a marker for advancing disease, and novel therapies could be developed for patients carrying these adaptive mutants. However, to address the utility of these approaches, our preliminary epidemiologic findings must be validated in a larger, multicenter population. We aim to define the prevalence and associated clinical features of LasR mutant P. aeruginosa infection among the young children enrolled in the EPIC trials, to test the hypothesis that LasR mutation occurs relatively commonly and early during P. aeruginosa CF infections, and is associated with preceding antibiotic exposure, accelerated decline in lung function, and more frequent respiratory exacerbations. Here, we also propose to compare results concerning LasR mutation with those for other common P. aeruginosa CF adaptive changes in this population. The results of this study will clarify the natural history of CF lung disease, and may lead to improvements in current CF therapeutic regimens.

描述（由申请人提供）：肺部疾病是遗传性疾病囊性纤维化（CF）患者预期寿命和生活质量的主要决定因素。机会性革兰氏阴性细菌铜绿假单胞菌感染大多数CF患者的呼吸道，感染这种病原体显然与较差的呼吸结果相关。铜绿假单胞菌在生命早期感染CF气道。多年来，细菌适应CF气道环境并刺激炎症反应，这些炎症反应对根除感染无效，但会损害气道。制定预防铜绿假单胞菌定植和消除慢性感染的策略需要了解CF肺部疾病的细菌贡献的自然史。该提案描述了一个四年计划，以进一步建立独立的，转化研究的职业生涯为候选人。特别是，该候选人是一名训练有素的医生和微生物学家，他将继续他的临床研究培训，并将他的时间集中在他资助的合作项目上，以确定早期CF气道感染中铜绿假单胞菌变化的自然史。该项目使用铜绿假单胞菌临床分离株、相关临床数据和独特的临床研究指导机会，这些机会来自两项由当地主导的全国性CF微生物学研究——囊性纤维化早期抗假单胞菌治疗研究（EPIC）。具体来说，该项目将定义携带新发现的适应性变化的铜绿假单胞菌感染的临床相关性：编码主要转录调节因子LasR的基因失活突变。在我们的初步研究中，这种突变与肺功能加速衰退有关。可能与这一发现有关，初步证据表明LasR突变导致对CF治疗中最常用的抗生素的耐药性增加。相反，LasR突变体在体外对至少两类代谢抑制剂更敏感，这表明感染这些分离物的患者可以选择其他治疗策略。因此，慢性铜绿假单胞菌CF气道感染期间LasR突变的出现可能是疾病进展的标志，并且可以为携带这些适应性突变的患者开发新的治疗方法。然而，为了解决这些方法的实用性，我们的初步流行病学发现必须在更大的多中心人群中得到验证。我们的目的是确定LasR突变铜绿假单胞菌感染在EPIC试验中招募的幼儿中的患病率和相关临床特征，以验证LasR突变在铜绿假单胞菌CF感染中相对常见和早期发生的假设，并与先前的抗生素暴露、肺功能加速下降和更频繁的呼吸恶化有关。在这里，我们还建议将LasR突变的结果与该人群中其他常见铜绿假单胞菌CF适应性变化的结果进行比较。本研究的结果将阐明CF肺部疾病的自然历史，并可能导致目前CF治疗方案的改进。