Repurposing auranofin and ebselen for treatment of multidrug resistant pathogens

摘要 由革兰氏阳性病原体（包括艰难梭菌）引起的感染是死亡的主要原因。 耐甲氧西林金黄色葡萄球菌（MRSA）、肺炎链球菌和 耐万古霉素肠球菌（VRE）-每年至少造成84%的抗生素所致死亡， 耐药性感染C.艰难梭菌是最常见和最昂贵的医疗保健相关感染， 每年有29,000人死亡。在过去的30年里，只有一种新的抗生素，非达霉素，被批准用于 治疗C.艰难梭菌感染和复发率仍然很高的感染涉及高毒力菌株。 迫切需要具有改进功效的新药。不像昂贵和耗时的过程 药物再利用是一种新的方法，可以减少与药物再利用相关的时间、成本和风险。 药物创新本申请中提出的研究集中在重新利用一种非抗菌批准药物， 金诺芬和一种临床分子依布硒啉。这两种药物具有有效的抗菌活性， - 在临床范围内可实现的纳米摩尔浓度，针对多重耐药病原体，包括MRSA， VRE和C.很难我们已经证明（在体外和体内），这两种药物是优于药物的选择上级 并且能够1）杀死细胞内和持久的MRSA，2）破坏粘附的葡萄球菌生物膜， 3)抑制包括毒素产生在内的关键毒力因子，4）减少过度的宿主炎症反应， 与这些毒素相关的反应，5）显着降低细菌负荷和亲- MRSA皮肤损伤中的炎性细胞因子，和6）增强伤口愈合。这两种药物都有额外的 对C有利的品质艰难梭菌，包括：a）在临床范围内可实现的有效活性，B）抑制 毒素产生，c）中和C. d）通过抑制半胱氨酸蛋白酶结构域抑制芽孢杆菌毒素， 形成，e）抑制IL-8释放并保护细胞免受毒素的影响，f）防止肠定殖 g）在体外试验中上级优于所选择的药物。 事实上，金诺芬已被FDA批准为治疗肠道阿米巴病的新药， 目前正在进行治疗肠贾第虫病的II期临床试验，进一步验证了我们的方法。 我们在本申请中的总体目标是进一步验证金诺芬和依布硒啉作为潜在的治疗药物， 由多重耐药细菌病原体和C.很难 我们在MRSA、VRE和C.艰难梭菌将与其他病原体广泛相关， 有效和快速的补充了目前治疗细菌感染的方法。

Abstract Infections caused by Gram-positive pathogens, including Clostridium difficile, are a leading cause of mortality. Three species—methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae and vancomycin-resistant enterococcus (VRE)—are responsible annually for at least 84% of deaths due to antibiotic- resistant infections. C. difficile is the most common and costly healthcare-associated infection with an estimated 29,000 deaths annually. Only one new antibiotic, fidaxomicin, has been approved in the last 30 years for treatment of C. difficile infection and recurrence rates are still high for infections involving hypervirulent strains. There is a desperate need for new drugs with improved efficacy. Unlike the costly and time-consuming process of de novo drug discovery, drug repurposing is a novel method to reduce the time, cost and risk associated with drug innovation. Studies proposed in this application focus on repurposing one non-antimicrobial approved drug, auranofin, and one clinical molecule, ebselen. These two agents possess potent antibacterial activity, in a low nano molar concentration achievable at a clinical range, against multidrug-resistant pathogens, including MRSA, VRE, and C. difficile. We have demonstrated (in vitro and in vivo) that both drugs are superior to drugs of choice and are capable of 1) killing intracellular and persistent MRSA, 2) disrupting adherent staphylococcal biofilms, 3) suppressing key virulence factors including toxin production, 4) reducing excessive host-inflammatory responses associated with these toxins, 5) significantly reducing both the bacterial load and levels of the pro- inflammatory cytokines in MRSA skin lesions, and 6) enhancing wound healing. Both drugs have additional advantageous qualities against C. difficile including; a) potent activity achievable in a clinical range, b) inhibiting toxin production, c) neutralizing C. difficile toxins by inhibiting the cysteine protease domain, d) inhibiting spore formation, e) inhibiting IL-8 release and protecting cells from effect of toxins, f) preventing intestinal colonization of VRE, and were g) superior to drugs of choice in in vitro testing. The fact that auranofin has been granted orphan-drug status from the FDA for treatment of intestinal amebiasis, and is currently in a Phase II clinical trial for treatment of intestinal giardiasis, further validates our approach. Our overall goal in this application is to further validate auranofin and ebselen as potential treatments for superficial, systemic and intestinal infections caused by multidrug-resistant bacterial pathogens and C. difficile. Our findings in MRSA, VRE and C. difficile will be broadly relevant to other pathogens and may offer a safe, effective, and quick supplement to current approaches for treating bacterial infections.