Strategies for improving the efficacy of combinatorial antibiotic therapy in chronic infections

项目摘要/摘要 随着耐药性机制的出现，抗生素耐药性的传播越来越令人担忧 在人类病原体之间发生的速度比开发新的抗菌剂更快。这一期 导致无法完全清除持续性感染，如慢性伤口和肺部感染， 是人类发病率和死亡率的主要来源。反过来，无法根除这些顽固的 感染为新的微生物机制的进化创造了更多的机会来规避治疗 治疗，加剧了抗生素耐药性问题。慢性感染有多个方面 导致治疗失败和出现抗生素耐药性的环境。首先，有几个 在宿主-病原体交界处遇到的应激源是诱变的，这有助于推动进化适应 在这些网站上。其次，许多慢性感染的多菌性可能会导致肺炎的传播。 通过水平基因转移的抗性机制。多菌群落的存在还可以进一步 复合感染的治疗清除问题，因为已知物种间的微生物相互作用 改变细菌生理并导致抗菌素耐受性。在这项建议中，我们寻求同时针对 宿主-病原体界面的微生物进化轨迹与慢性感染的多菌特性 设计改进的治疗策略，以根除导致其他方面持续存在的病原体 感染。在目标1中，我们建议通过鉴定易感性来针对抗生素耐药菌株。 当细胞改变其基本生理以应对抗生素暴露时可能发生的权衡。此外 对于已发表的这种现象的例子，我们展示了我们发现权衡的新例子的能力。 可以被利用来根除原本顽固的微生物。我们试图发现更多的例子 在慢性阻塞性肺疾病小鼠模型中进行脆弱性权衡，并确定靶向这些权衡的有效性 伤口感染。在目标2中，我们建立了多菌群创伤病原体模型，并使用了一种 我们提出的方法学可以用于临床实验室，以显示抗生素的变化 由多个微生物相互作用驱动的功效。我们证明了多菌协同作用(减少了 抗生素在复杂细菌群落中的效力)和多菌拮抗(抗生素的增加 在多微生物联合体的情况下的有效性)可以容易地观察到。初步数据显示， 可以开发组合治疗策略来利用多菌拮抗来克服协同作用 互动。我们建议在慢性伤口感染的小鼠模型中验证这一策略。加在一起，这些 AIMS将被用来确定抗生素治疗策略，以延长目前可用的 所有的抗生素。

Project Summary/Abstract The spread of antibiotic resistance is a growing concern as the emergence of resistance mechanisms among human pathogens is occurring more rapidly than the development of new antimicrobial agents. This issue contributes to the inability to fully clear persistent infections such as chronic wound and lung infections, which represent a major source of human morbidity and mortality. In turn, the inability to eradicate these persistent infections creates more opportunities for the evolution of novel microbial mechanisms to circumvent therapeutic treatment, exacerbating the problem of antibiotic resistance. There are multiple aspects of the chronic infection environment that contribute to therapeutic failure and the emergence of antibiotic resistance. First, several stressors encountered at the host-pathogen interface are mutagenic, which helps drive evolutionary adaptation in these sites. Second, the polymicrobial nature of many chronic infections can contribute to the spread of resistance mechanisms via horizontal gene transfer. The presence of polymicrobial communities can also further compound the issue of therapeutic clearance of infection since interspecies microbial interactions are known to alter bacterial physiological and lead to antimicrobial tolerance. In this proposal, we seek to target both the microbial evolutionary trajectory at the host-pathogen interface and the polymicrobial nature of chronic infections to design improved therapeutic strategies for eradication of pathogens contributing to otherwise persistent infections. In Aim 1, we propose to target antibiotic resistant isolates through the identification of vulnerability tradeoffs that can occur as the cell shifts its fundamental physiology to cope with antibiotic exposure. In addition to published examples of this phenomenon, we demonstrate our ability to uncover novel examples of tradeoffs that can be exploited to eradicate otherwise recalcitrant microorganisms. We seek to uncover more examples of vulnerability tradeoffs and determine the effectiveness of targeting these tradeoffs in a murine model of chronic wound infection. In Aim 2, we establish polymicrobial community wound pathogen models and use a methodology that we propose can be adapted for use in the clinical laboratory to demonstrate shifts in antibiotic efficacy driven by polymicrobial interactions. We demonstrate that both polymicrobial synergism (a reduction in antibiotic efficacy in complex bacterial communities) and polymicrobial antagonism (an increase in antibiotic efficacy in the context of a polymicrobial consortium) can be readily observed. Preliminary data suggest that combinatorial treatment strategies can be developed to exploit polymicrobial antagonism to overcome synergistic interactions. We propose to validate this strategy in a murine model of chronic wound infection. Together, these Aims will be used to identify antibiotic treatment strategies that will extend the efficacy of the currently available repertoire of antibiotics.