Elucidating bacterial responses to the novel antimicrobial AGXX

阐明细菌对新型抗菌剂 AGXX 的反应

基本信息

批准号：
10742217
负责人：
Jan-Ulrik Dahl
金额：
$ 7.4万
依托单位：
ILLINOIS STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-07-01 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10742217
关键词：
Acute Adjuvant Affect Aminoglycoside Antibiotics Aminoglycosides Antibiotic Resistance Antibiotics Antimicrobial Resistance Bacterial Infections Cell Line Cells Clinical Combined Modality Therapy Data Defense Mechanisms Development Drug resistance Effectiveness Formulation Goals Gram-Negative Bacteria Gram-Positive Bacteria Growth Homeostasis Hydrogen Peroxide Hydroxyl Radical Infection Iron Lead Life Style Mediating Medical Device Membrane Microbial Biofilms Molecular Oxidation-Reduction Patients Phenotype Polyphosphates Predisposition Prevention strategy Production Property Proteins Pseudomonas aeruginosa Pseudomonas aeruginosa infection Pulmonary Cystic Fibrosis Reaction Reactive Oxygen Species Reporting Resistance Ruthenium Sepsis Silver Silver Compounds Stress Sulfadiazine Sulfur Superoxides System Testing Tissues Transition Elements Urinary tract infection Wound Infection alternative treatment antimicrobial bactericide burn therapy burn wound cellular targeting clinically relevant cystic fibrosis patients cytotoxicity drug development drug resistant pathogen electric field experimental study insight interest mutant novel novel therapeutics pathogen prevent proteotoxicity response surface coating synergism transposon sequencing treatment strategy uptake

项目摘要

SUMMARY New antimicrobial strategies are badly needed, as the spread of antibiotic resistance is rapidly compromising the effectiveness of current antibiotics. Moreover, new drug development has not kept pace with the rise of drug-resistant pathogens. Pseudomonas aeruginosa is particularly difficult to treat and commonly found in the lungs of cystic fibrosis patients or in patients with burn wounds. Due to the emerging antibiotic crisis, efforts are now focused on finding alternative treatment strategies. Silver-containing compounds represent such opportunity due to their multi-specific ability to inhibit bacterial growth. One example is silver sulfadiazine, a topical formulation that is often administered to treat or prevent acute P. aeruginosa wound infections. The novel silver containing surface coating AGXX was recently developed as a promising compound with antimicrobial properties. Composed of the two transition metals silver and ruthenium which form a micro-galvanic cell, AGXX kills gram-positive bacteria through the formation of reactive oxygen species, such as hydrogen peroxide. However, its effect on gram-negative bacteria such as P. aeruginosa as well as their responses to AGXX exposure have not yet been studied. We found that AGXX elicits strong proteotoxic effects in P. aeruginosa even at sublethal concentrations, and that the compound is significantly more potent than silver sulfadiazine, the gold standard for the treatment of burn wounds. Moreover, we discovered that the bactericidal activity of sublethal concentrations of AGXX is up to 50,000-fold higher in the presence of sublethal aminoglycosides concentrations, indicating a potential application for AGXX as an adjuvant. We will now investigate the molecular mechanism behind the synergy of aminoglycoside antibiotics and AGXX. In Aim 1, we will test our hypothesis that AGXX-induced ROS production disrupts the cellular iron-sulfur cluster pool and therefore triggers hydroxyl radical production via the Fenton reaction. As a result, we expect to observe increased membrane disruption, potentially facilitating an elevated aminoglycoside influx into the cell, which is responsible for increased bacterial killing that is observed after simultaneous treatment of P. aeruginosa with AGXX and aminoglycosides. Furthermore, we will determine the effect a combinational treatment has on P. aeruginosa biofilms and persister cells and on isolates of other clinically relevant bacterial species. In Aim 2, we will use independent unbiased and targeted approaches, including Tnseq and subsequent phenotypic characterization of transposon mutants, to identify and determine P. aeruginosa-specific responses to and defenses against AGXX treatment. Moreover, we will assess the cytotoxicity of this compound in different cell lines of relevance. These findings will guide efforts to devise strategies to implement AGXX as a potential antimicrobial and adjuvant in eradicating P. aeruginosa infections.

概括由于抗生素耐药性迅速蔓延，迫切需要新的抗菌策略损害现有抗生素的有效性。此外，新药研发还没有跟上耐药病原体的增加。铜绿假单胞菌特别难以治疗且常见发现于囊性纤维化患者或烧伤患者的肺部。由于抗生素危机的出现，目前的工作重点是寻找替代治疗策略。含银化合物代表此类由于其抑制细菌生长的多特异性能力，因此具有机会。一个例子是磺胺嘧啶银，一种通常用于治疗或预防急性铜绿假单胞菌伤口感染的局部制剂。新型含银表面涂层 AGXX 最近被开发为一种有前景的化合物，具有抗菌特性。由两种过渡金属银和钌组成，形成微电偶 AGXX 通过形成活性氧（例如氢）来杀死革兰氏阳性细菌过氧化物。然而，它对革兰氏阴性菌（如铜绿假单胞菌）的影响及其对 AGXX 暴露尚未进行研究。我们发现 AGXX 在 P. 即使在亚致死浓度下，铜绿假单胞菌也如此，并且该化合物比银更有效磺胺嘧啶，治疗烧伤创面的金标准。此外，我们还发现，杀菌剂在存在亚致死浓度的情况下，AGXX 的亚致死浓度活性高达 50,000 倍氨基糖苷类浓度，表明 AGXX 作为佐剂的潜在应用。我们现在将研究氨基糖苷类抗生素与抗生素协同作用背后的分子机制。 AGXX。在目标 1 中，我们将检验我们的假设，即 AGXX 诱导的 ROS 产生会破坏细胞的铁硫簇池，因此通过芬顿反应触发羟基自由基的产生。因此，我们期望观察到膜破裂增加，可能促进氨基糖苷类药物流入细胞的增加，它是同时处理铜绿假单胞菌后观察到的细菌杀灭增加的原因与 AGXX 和氨基糖苷类药物一起使用。此外，我们将确定联合治疗对 P 的影响。铜绿假单胞菌生物膜和存留细胞以及其他临床相关细菌种类的分离株。在目标 2 中，我们将使用独立、公正和有针对性的方法，包括 Tnseq 和随后的表型转座子突变体的表征，以识别和确定铜绿假单胞菌的特异性反应针对 AGXX 治疗的防御。此外，我们将评估该化合物在不同细胞中的细胞毒性相关线。这些发现将指导制定战略以实施 AGXX 作为潜在的根除铜绿假单胞菌感染的抗菌剂和佐剂。