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，恢复细菌的抗生素敏感性，这些细菌会导致住院或接受其他疾病医疗保健的患者严重感染。抗生素对现代医学至关重要。除了治疗感染和控制其传播外，这些药物还可以实现安全手术，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产生耐药性，这些拯救生命的药物正在失去效力。已经确定了11种有效和特异性的小分子，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流感染和呼吸机相关肺炎是两种严重的医疗保健相关感染，尽管目前的治疗导致显著的死亡率过高（150例死亡/1，000例患者），住院时间更长，估计每位患者的增量成本接近50，000美元。开发能够恢复多重耐药（MDR）革兰氏阴性病原体对常用、耐受性良好的抗生素敏感性的治疗药物，解决了一个主要的未满足的医疗需求，对患者和医生都具有变革性意义。该项目涉及开发小分子药物，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MDR革兰氏阴性菌中的作用已得到充分证实。这些泵是感染所必需的毒力决定因素，通过将抗生素输出到细菌细胞包膜，它们在抗生素耐药性中发挥关键作用。已经鉴定了11种细菌外排泵（EPI）的有效和特异性小分子抑制剂。这些EPI处于早期先导化合物优化阶段，该项目涉及三项基础试验：冷冻电子显微镜（cryo-EM）、膜渗透性和体外抗生素组合试验，随后是体外表征、安全药理学和责任筛选。Cryo-EM提供了对这些EPI与外排泵的作用和结合机制的深入了解，从而实现了计算机对接研究和新类似物的设计。一些先前的EPI研究由于膜透化而失败，这是一种可导致明显体外功效的性质。Cryo-EM数据以及体外功效和膜渗透性测定的结果允许早期取消选择质量差的化合物，将筛选研究集中在最有前途的EPI上。该项目可能提供对MDR、持留细胞和革兰氏阴性病原体毒力之间联系的深入了解。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值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.