SBIR Phase I: Combating Multi-Drug Resistant Gram-negative Healthcare-Associated Infections

这个小企业创新研究(SBIR)第一阶段项目的更广泛影响是开发治疗药物，恢复细菌对抗生素的敏感性，这些细菌会导致因其他疾病住院或接受医疗保健的患者发生严重感染。抗生素对现代医学来说是至关重要的。除了治疗感染和控制其传播外，这些药物还可以安全地进行外科手术，促进分娩，并为癌症等疾病提供治疗。然而，随着微生物的进化和抗药性的产生，这些救命药物正在失去效力。已经确定了11个有效和特定的小分子，它们可以恢复这些细菌的抗生素敏感性。由革兰氏阴性菌引起的血液感染和呼吸机相关肺炎是两种严重的医疗保健相关感染，尽管目前的治疗方法会导致显著的超额死亡率(每1000名患者中有150人死亡)、更长的住院时间，以及估计每个患者近50,000美元的增量成本。开发恢复多重耐药(MDR)革兰氏阴性病原体对常用、耐受性良好的抗生素的敏感性的疗法，解决了一个主要的未得到满足的医疗需求，并将对患者和医生产生革命性影响。该项目涉及开发小分子，以恢复多重耐药(MDR)革兰氏阴性细菌对常用、耐受性良好的抗生素的敏感性。细菌外排泵在耐多药革兰氏阴性菌中的作用是有充分证据的。这些泵是感染必不可少的毒力决定因素，通过跨细菌细胞膜输出抗生素，它们在抗生素耐药性中发挥关键作用。已鉴定出11种有效和特异的细菌外排泵(Epis)小分子抑制剂。这些EPI处于早期先导优化阶段，该项目涉及三项基本分析：冷冻电子显微镜(CRYO-EM)、膜通透性和体外抗生素组合分析，随后是体外表征、安全药理学和易感性筛选。CRYO-EM可以深入了解这些EPI的作用机制和与外排泵的结合，从而能够进行硅胶对接研究和设计新的类似物。先前的一些EPI研究由于膜通透性而失败，这一特性可以导致明显的体外疗效。低温电子显微镜数据与体外药效和膜通透性分析的结果相结合，可以及早取消对劣质化合物的选择，重点筛选最有希望的EPI。该项目可能提供对耐多药、持久细胞和革兰氏阴性病原体毒力之间的联系的洞察。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact of this Small Business Innovation Research (SBIR) Phase I project is to develop therapeutic drugs that restore antibiotic sensitivity in bacteria that cause severe infections in patients that are hospitalized or receiving healthcare for another condition. Antibiotics are paramount to modern medicine. In addition to treating infections and controlling their spread, these drugs enable safe surgeris, facilitate childbirth, and provide treatments for diseases such as cancer. However, as microbes evolve and develop resistance, these life-saving drugs are losing effectiveness. Eleven potent and specific small molecules have been identified that restore antibiotic sensitivity in these bacteria. Bloodstream infections and ventilator-associated pneumonia caused by Gram-negative bacteria are two severe healthcare associated infections that despite current treatments cause significant excess mortality (150 deaths/1,000 patients), longer hospital stays, and incremental costs estimated at nearly $50,000 per patient. Developing therapeutics that restore the sensitivity of Multi-Drug Resistant (MDR) Gram-negative pathogens to commonly used, well tolerated antibiotics addresses a major unmet medical need and would be transformative for patients and physicians.This project involves developing small molecules to restore the sensitivity of Multi-Drug Resistant (MDR) Gram-negative bacteria to commonly used, well tolerated antibiotics. The role of bacterial efflux pumps in MDR Gram-negative bacteria is well documented. These pumps are virulence determinants essential for infection, and by exporting antibiotics across the bacterial cell envelope they play a key role in antibiotic resistance. Eleven potent and specific small molecule inhibitors of bacterial efflux pumps (EPIs) have been identified. These EPIs are in early-stage lead optimization and this project involves three foundational assays: cryo-electron microscopy (cryo-EM), membrane permeability, and in vitro antibiotic combination assays, followed by in vitro characterization, safety pharmacology, and liability screening. Cryo-EM provides insight into the mechanism of action and binding of these EPIs to the efflux pump, enabling in-silico docking studies and the design of new analogs. Some prior EPI research failed due to membrane permeabilization, a property that can result in apparent in vitro efficacy. Cryo-EM data together with results from in vitro efficacy and membrane permeability assays allows early deselection of poor-quality compounds, focusing screening studies on the most promising EPIs. This project may provide insights into links between MDR, persister cells, and virulence in Gram-negative pathogens.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.