Staphylococcus aureus and Pseudomonas aeruginosa interactions in wound pathogenesis

金黄色葡萄球菌和铜绿假单胞菌在伤口发病机制中的相互作用

基本信息

批准号：
10531680
负责人：
ALEXANDER R HORSWILL
金额：
$ 18.73万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-06-01 至 2024-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10531680
关键词：
Accounting Address Affect Anabolism Antibiotic Resistance Antibiotic Therapy Antibiotics Binding Biochemical Genetics Biological Chemicals Chronic Collaborations Communities Data Development Disease Disease Outcome Elements Enterococcus Environment Enzymes Exposure to Gene Expression Gene Proteins Generations Genes Genus staphylococcus Goals Growth Immune system In Vitro Infection Iron Knowledge Lead Leg Ulcer Libraries Metabolic Biotransformation Metabolism Metabolite Interaction Methods Methylation Methyltransferase Microbial Biofilms Modeling Modification Morbidity - disease rate Mus Outcome Pathogenesis Pathway interactions Patients Persons Physiology Prevalence Production Property Pseudomonas Pseudomonas aeruginosa Pyocyanine Quinolones Recurrence Regulation Siderophores Signal Pathway Site Skin Tissue Soft Tissue Infections Staphylococcus aureus Surveillance Program System Testing United States Virulence Factors Work Wound Infection Wound models alternative treatment antibiotic tolerance antimicrobial cell behavior chronic infection chronic wound co-infection genetic analysis immune clearance improved mass spectrometric imaging methicillin resistant Staphylococcus aureus microbial community mutant novel pathogen pathogenic bacteria polymicrobial disease pyochelin quorum sensing receptor recurrent infection screening uptake wound wound environment

项目摘要

PROJECT ABSTRACT Patients with chronic wound infections have a rich microbial community and several bacterial species have been identified as the main drivers of persistent disease. Two of the most prominent wound pathogens are Staphylococcus aureus (including methicillin-resistant S. aureus (MRSA)), and Pseudomonas aeruginosa. The SENTRY antimicrobial surveillance program identified S. three 11%, aureus P. aeruginosa and Enterococcus spp. as the main pathogens causing skin and soft tissue infections (SSTI) in the United States accounting for 44%, and 9% of all SSTI during the years 1998 and 2004. , , Chronic leg ulcers (CLUs) affect 1-2% of people worldwide, are a major cause of prolonged morbidity and have a high recurrence rate. S. aureus and P. aeruginosa are the most common agents isolated from CLUs usually as biofilm resistant to antibiotic therapy. Biofilms are notoriously difficult to eradicate, due to their recalcitrance to antibiotics and ability to evade clearance by the immune system. There is evidence that these two pathogens can exchange specialized metabolites that have the potential to alter cellular behavior and lead to community-wide antibiotic tolerance. Specifically, in vitro co-cultivation studies with S. aureus increased Pseudomonas quinolone gene expression that regulates the expression of several quorum-sensing dependent P. aeruginosa virulence factors and iron acquisition systems. As the prevalence of MRSA increases in the US, new strategies are necessary to treat chronic and recurrent infections. Therefore, the long-term goal is to develop alternative treatment options for chronic wound patients infected by S. aureus and P. aeruginosa. The objective of this proposal is to determine the biological consequences of MRSA modification of P. aeruginosa pyochelin. The rationale underlying this proposal is our preliminary findings that S. aureus and P. aeruginosa act synergistically, which may in part explain why co- infections with these two pathogens lead to worse outcomes. In preliminary imaging mass spectrometry studies, we determined that a novel methylated pyochelin derivative is produced during the interaction of MRSA and P. aeruginosa. We identified the MRSA gene responsible and we can detect this new metabolite in a mouse wound infection model. Our initial studies confirm that the pyochelin originates from P. aeruginosa and then is enzymatically converted by MRSA into a new methylated form. We hypothesize that MRSA methylates pyochelin to compete in a polymicrobial environment. In order to test this hypothesis we will (i) characterize methylated pyochelin generated by MRSA through biochemical, genetic and infection modeling methods and; (ii) determine the functional consequences of methylated pyochelin on P. aeruginosa physiology and pathogenesis. The expected outcomes of this work will increase our understanding the biosynthesis and biological activities of specialized metabolites that drive inter-species interactions to better predict infection outcomes and to develop new treatment approaches.

项目摘要慢性伤口感染患者体内有丰富的微生物群落，并且已发现多种细菌种类。被认为是持续性疾病的主要驱动因素。两种最突出的伤口病原体是金黄色葡萄球菌（包括耐甲氧西林金黄色葡萄球菌 (MRSA)）和铜绿假单胞菌。这 SENTRY 抗菌药物监测计划发现了 S. 三 11%, 金黄色葡萄球菌、铜绿假单胞菌和肠球菌属。作为美国引起皮肤软组织感染（SSTI）的主要病原体占44%， 1998 年和 2004 年占所有 SSTI 的 9%。 , , 慢性腿部溃疡 (CLU) 影响 1-2% 的人在世界范围内，这是长期发病的主要原因，并且复发率很高。金黄色葡萄球菌和 P. 铜绿假单胞菌是从 CLU 中分离出来的最常见病原体，通常作为对抗生素治疗具有抗性的生物膜。众所周知，生物膜很难根除，因为它们对抗生素有抵抗力并且能够逃避清除通过免疫系统。有证据表明这两种病原体可以交换专门的代谢物有可能改变细胞行为并导致社区范围内的抗生素耐受性。具体来说，在体外与金黄色葡萄球菌的共培养研究增加了假单胞菌喹诺酮基因的表达，从而调节几种群体感应依赖性铜绿假单胞菌毒力因子和铁获取系统的表达。随着美国 MRSA 患病率的增加，需要新的策略来治疗慢性和复发性感染。因此，长期目标是为慢性伤口患者开发替代治疗方案被金黄色葡萄球菌和铜绿假单胞菌感染。该提案的目的是确定生物铜绿假单胞菌绿脓杆菌 MRSA 修饰的后果。该提案的基本原理是我们初步发现金黄色葡萄球菌和铜绿假单胞菌具有协同作用，这可能部分解释了为什么共同作用这两种病原体的感染会导致更糟糕的结果。在初步成像质谱研究中，我们确定，MRSA 和 P 相互作用时会产生一种新型甲基化脓毒素衍生物。铜绿假单胞菌。我们确定了负责的 MRSA 基因，并且可以在小鼠伤口中检测到这种新的代谢物感染模型。我们的初步研究证实，绿脓菌素源自铜绿假单胞菌，然后被被 MRSA 酶促转化为新的甲基化形式。我们假设 MRSA 甲基化 pyochelin 在多种微生物环境中竞争。为了检验这个假设，我们将 (i) 描述 MRSA 通过生化、遗传和感染建模方法产生甲基化绿脓杆菌； (ii) 确定甲基化绿脓菌素对铜绿假单胞菌生理学的功能影响，以及发病。这项工作的预期成果将增加我们对生物合成和驱动物种间相互作用以更好地预测感染的专门代谢物的生物活性结果并开发新的治疗方法。