Brindangnanam Pownraj, Sawant Ajit Ramesh, Ashokkumar Krishnan, Sriraghavan Kamaraj, P Shashikala, Prashanth K, Coumar Mohane Selvaraj
Department of Bioinformatics, School of Life Sciences, Pondicherry University, Kalapet, Pondicherry 605014, India.
Department of Biotechnology, School of Life Sciences, Pondicherry University, Kalapet, Pondicherry, 605014, India.
Microb Pathog. 2025 Jun;203:107513. doi: 10.1016/j.micpath.2025.107513. Epub 2025 Mar 26.
ESKAPEE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp. and Escherichia coli) is a group of nosocomial pathogens with alarming antibiotic resistance, representing a paramount public health menace. Their multidrug resistance (MDR) is often due to hyperactive drug efflux transporters (DETs) exporting antibiotics from bacterial cells. Fortunately, a breakthrough has been made by the synthetic molecule KSA5_1 (8,10-dimethyl-1,6,11-triazatetracene-5,12-dione). In vitro combination assays of KSA5_1 with antibiotics (colistin, ciprofloxacin, gentamicin) showed excellent reductions in minimum inhibitory concentrations (MICs), as much as 512-fold, against clinical MDR isolates such as Enterococcus faecium, Staphylococcus aureus and Acinetobacter baumannii. Surprisingly, KSA5_1 was more effective than the standard efflux pump inhibitor PAβN in inhibiting ciprofloxacin efflux from A. baumannii, primarily targeting the overexpressed AdeG gene, a key DET protein. Molecular docking and simulations indicated the improved binding of KSA5_1 to AdeG with a suggestion of tight DET inhibition. KSA5_1 also possessed good drug-like profiles. The improved physicochemical profile of the compound and the potential to increase the efficacy of antibiotics by inhibiting DETs offer KSA5_1 an exciting lead to combat antimicrobial resistance (AMR). The new approach promises to address the challenging issue of MDR among ESKAPEE pathogens and has the potential to restore the efficacy of existing antibiotics to combat the AMR crisis.
ESKAPEE（粪肠球菌、金黄色葡萄球菌、肺炎克雷伯菌、鲍曼不动杆菌、铜绿假单胞菌、肠杆菌属和大肠杆菌）是一组具有惊人抗生素耐药性的医院病原体，是对公共卫生的重大威胁。它们的多重耐药性（MDR）通常是由于超活性药物外排转运蛋白（DETs）将抗生素从细菌细胞中输出。幸运的是，合成分子KSA5_1（8,10 - 二甲基 - 1,6,11 - 三氮杂十四烷 - 5,12 - 二酮）取得了突破。KSA5_1与抗生素（黏菌素、环丙沙星、庆大霉素）的体外联合试验表明，针对粪肠球菌、金黄色葡萄球菌和鲍曼不动杆菌等临床MDR分离株，其最低抑菌浓度（MICs）有显著降低，高达512倍。令人惊讶的是，KSA5_1在抑制环丙沙星从鲍曼不动杆菌中流出方面比标准外排泵抑制剂PAβN更有效，主要靶向过表达的AdeG基因，这是一种关键的DET蛋白。分子对接和模拟表明KSA5_1与AdeG的结合得到改善，提示对DETs有紧密抑制作用。KSA5_1还具有良好的类药性质。该化合物改善的物理化学性质以及通过抑制DETs提高抗生素疗效的潜力，使KSA5_1成为对抗抗菌药物耐药性（AMR）的一个令人兴奋的先导物。这种新方法有望解决ESKAPEE病原体中具有挑战性的MDR问题，并有可能恢复现有抗生素对抗AMR危机的疗效。
