Potentiating antibiotics against Campylobacter by inhibiting efflux

描述(申请人提供)：空肠弯曲杆菌是一种主要的肠道病原体，导致全球范围内大量的胃肠炎。弯曲杆菌病的临床治疗需要使用氟喹诺酮类或大环内酯类抗生素，但耐药弯曲杆菌日益流行，影响了抗生素治疗的有效性。迫切需要新的策略来控制由耐药弯曲杆菌引起的感染。在弯曲杆菌产生抗生素耐药性的各种机制中，CmeABC多药外排泵在对多种抗菌剂和有毒化合物的耐药性中起着关键和主导的作用。这种外排系统也在抗生素选择下促进敏感弯曲杆菌产生氟喹诺酮耐药突变株方面发挥了重要作用。为了开发新的方法来对抗耐药弯曲杆菌，我们已经开始了探索使用反义多肽核酸(PNA)靶向CmeABC的可行性的研究。我们的初步结果表明，反义PNA方法有很强的潜力抑制cmeABC的表达，并使弯曲杆菌对抗生素敏感。在这一应用中，我们将进一步开发和评估反义PNA方法作为耐药弯曲杆菌的辅助治疗方法。R21阶段的具体目的是开发和评估有效增强抗生素对耐药弯曲杆菌的抗生素的抗CmeABC PNAS，R33阶段的具体目标是评估在动物模型中使用抗CmeABC PNAS作为辅助治疗对抗耐药弯曲杆菌的可行性，确定PNAS在防止敏感弯曲杆菌产生氟喹诺酮耐药突变株方面的有效性，并通过修饰细胞穿透肽来提高PNAS的通透性和稳定性。这项工作利用了一种新的靶点(CmeABC)和一种新的技术(反义PNA)，并利用了体外和体内的方法。一旦完成，该项目将开发出一种有效的手段，扩大现有抗生素对耐药弯曲杆菌的效用。此外，该项目建立的技术平台可能适用于其他耐药病原体。因此，这项工作不仅将极大地推动抗药性弯曲杆菌新辅助疗法的发现，而且可能有助于其他病原体治疗的发展。 与公共卫生相关：空肠弯曲杆菌是一种引起人类胃肠炎的主要肠道病原体。弯曲杆菌中抗生素耐药性的流行已成为公共卫生的主要问题。该项目将大大推进辅助疗法的发现，这些辅助疗法将扩大现有抗生素在治疗由耐药弯曲杆菌引起的感染方面的效用。

DESCRIPTION (provided by applicant): Campylobacter jejuni is a major enteric pathogen and is responsible for a large number of gastroenteritis worldwide. Clinical treatment of campylobacteriosis requires the use of fluoroquinolone or macrolide antibiotics, but antibiotic-resistant Campylobacter is increasingly prevalent, compromising the effectiveness of antibiotic therapy. Novel strategies are urgently needed to control infections caused by antibiotic-resistant Campylobacter. Among the various mechanisms utilized by Campylobacter for antibiotic resistance, the CmeABC multidrug efflux pump is a critical and predominant player in the resistance to a wide range of antimicrobials and toxic compounds. This efflux system also plays an important role in facilitating the emergence of fluoroquinolone-resistant mutants from susceptible Campylobacter under antibiotic selection. To develop novel measures to combat antibiotic-resistant Campylobacter, we have initiated studies to explore the feasibility of using antisense Peptide Nucleic Acid (PNA) to target CmeABC. Our preliminary result suggests that the antisense PNA approach has a strong potential to inhibit the expression of cmeABC and sensitize Campylobacter to antibiotics. In this application, we will further develop and evaluate the antisense PNA approach as an adjunctive therapy for antibiotic-resistant Campylobacter. The Specific aim for the R21 phase is to develop and evaluate anti-CmeABC PNAs that effectively potentiate antibiotics against antimicrobial-resistant Campylobacter and the specific aims for the R33 phase are to assess the feasibility of using anti-CmeABC PNAs as an adjunctive therapy to combat antibiotic-resistant Campylobacter in an animal model, determine the efficiency of PNAs in preventing the emergence of fluoroquinolone-resistant mutants from susceptible Campylobacter, and improve the permeability and stability of PNAs by modifying cell-penetrating peptides. The proposed work takes advantage of a novel target (CmeABC) and a novel technology (antisense PNA) and utilizes both in vitro and in vivo methodologies. Once completed, the project will have developed an effective mean to extend the utility of existing antibiotics against drug-resistant Campylobacter. Furthermore, the technical platform established in this project can be potentially adapted for other antibiotic-resistant pathogens. Thus the work will not only significantly advance the discovery of novel adjunctive therapies for antibiotic-resistant Campylobacter, but also potentially benefit the development of therapy for other pathogens. PUBLIC HEALTH RELEVANCE: Campylobacter jejuni is a major enteric pathogen causing gastroenteritis in humans. Prevalence of antibiotic resistance in Campylobacter has become a major concern for public health. This project will significantly advance the discovery of adjunctive therapies that will extend the utility of existing antibiotics in treating infections cased by resistant Campylobacter.