Anti-biofilm activity of bacteriophage-antibiotic combinations against MRSA

摘要/摘要 由耐甲氧西林金黄色葡萄球菌(MRSA)引起的感染是有问题的 因为相关的治疗失败和高死亡率。葡萄球菌 包括耐甲氧西林金黄色葡萄球菌在内，是医疗器械感染(MDI)的主要原因，因为 形成生物膜的能力。这些细菌生物膜抵抗宿主免疫系统并导致 抗生素渗透率有限、细菌耐受性和 抗生素耐药性。万古霉素是治疗MRSA MDIs和达托霉素的推荐药物 是治疗这些感染的主要抗生素替代万古霉素；然而， 达托霉素的耐药性，特别是万古霉素治疗后的耐药性，已有报道 频率尽管万古霉素或达托霉素与β-内酰胺类药物联合治疗 像头孢他林这样的抗生素在体外表现出了更好的活性，这些组合 在葡萄球菌引起的MDIs方面没有显示出显著的增强。因此，由于 由于缺乏有效的MDI治疗，迫切需要新的抗菌选择。义不容辞 裂解噬菌体(噬菌体)感染细菌，在细胞内复制，裂解细胞释放 并重新启动感染循环。这些噬菌体消除了对抗生素敏感的和 浮游生物和生物膜形式的抗药性细菌。噬菌体和抗生素的结合有 研究表明，它能使以前具有多重耐药性的细菌对抗生素重新敏感。协同和 噬菌体-抗生素组合中的拮抗相互作用高度依赖于 与噬菌体、细菌宿主状态(生物膜)配对的抗生素的抑菌机制 相对于浮游生物)和细菌生长年龄。在这里，我们提供了一个系统的调查 噬菌体抗生素组合使用各种标准的护理抗生素(SOC)来检查 上述参数。这项拟议的研究意义重大，尤其是由于缺乏 有关使用含有SOC抗生素的噬菌体对抗生物膜包埋MRSA的信息 菌株。我们的中心假设是，噬菌体-抗生素的组合将减少 抗生物被膜MRSA所需的万古霉素和达托霉素暴露 并进一步防止抗生素耐药性的出现。我们将通过以下方式测试我们的中心假设 首次评价生物膜包埋耐甲氧西林金黄色葡萄球菌对多种噬菌体抗生素的敏感性 联合，然后进行体外二室PK/PD生物膜模型 人源化药代动力学以优化新型噬菌体-抗生素联合疗法。我们 期望通过优化MRSA-生物被膜感染的治疗，改善患者护理 延长万古霉素和达托霉素在MRSA MDIs管理中的使用寿命。

Summary/Abstract Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are problematic because of the high associated treatment failures and elevated mortality rates. Staphylococci including MRSA are the major cause of medical device infections (MDIs) due to their strong capability to form biofilms. These bacterial biofilms resist host immune system and lead to antibiotic failure due to limited antibiotic penetration, bacterial tolerance and development of antibiotic resistance. Vancomycin is the recommended therapy for MRSA MDIs and daptomycin is the primary antibiotic alternative to vancomycin for these infections; however, the development of daptomycin resistance especially post vancomycin therapy has been reported with increasing frequency. Although combination therapy of vancomycin or daptomycin with beta-lactam antibiotics such as ceftaroline have demonstrated improved activity in vitro, these combinations have not shown significant enhancements in MDIs caused by Staphylococci. Therefore, due to the lack of effective MDI treatments, novel antibacterial options are critically needed. Obligately lytic bacteriophages (phages) infect bacteria, replicate within the cell, lyse the cell to release their progeny and reinitiate the infection cycle. These phages eradicate both antibiotic susceptible and resistant bacteria in planktonic and biofilm forms. The combination of phage and antibiotics have shown to re-sensitize previously multi-drug resistant bacteria to antibiotics. Synergistic and antagonistic interactions in phage-antibiotic combinations are highly dependent on the mechanism of bacterial inhibition of the antibiotic paired to the phage, bacterial host state (biofilm versus planktonic) and bacterial growth age. Here we are offering a systematic investigation of phage antibiotic combination using various standard of care antibiotics (SOC) to examine the aforementioned parameters. The proposed research is significant especially due to lack of information regarding the use of phage with SOC antibiotics against biofilm embedded MRSA strains. Our central hypothesis is that the combination of phage-antibiotic will reduce the vancomycin and daptomycin exposures required for efficacy against biofilm embedded MRSA and further prevent the emergence of antibiotic resistance. We will test our central hypothesis by first evaluating susceptibility of biofilm embedded MRSA to various phage-antibiotic combinations and then performing in vitro two-compartment PK/PD biofilm models with humanized pharmacokinetics to optimize novel phage-antibiotic combination therapies. We expect that through optimizing therapy of MRSA-biofilm infections, we will improve patient care and prolong the useful life of vancomycin and daptomycin for the management of MRSA MDIs.