Treatment of Multidrug-Resistant Staphylococcus aureus Orthopaedic-Device Related Biofilm Infections with Local Delivery of Lytic Bacteriophage

摘要： 骨髓炎由骨科设备相关感染(ODRI)引起，是骨科的主要并发症 医学，导致美国每年约有200,000例病例(约占估计600万选修课的3% 整形外科手术)，预计随着美国人口老龄化，这一数字将会上升。目前的治疗需要4到6次 几周的静脉注射抗生素和多次手术以移除受感染的植入物和周围 组织和修复装置，导致巨大的经济负担和严重的病人发病率。ODRI是 对抗生素治疗极其顽固，因为这些是生物被膜感染，其中的细菌病原体 附着在由自制基质包围的表面上。生物膜的一个特点是它们对 抗生素和宿主免疫系统。此外，口服或非肠道注射抗生素 (静脉或肌肉注射)骨穿透性差。另一种治疗并发症 是由于抗生素和多药耐药(MDR)细菌导致的ODRI的增加。通过以下方式在当地交付抗生素 它们与聚甲基丙烯酸甲酯(PMMA)珠子的结合改善了治疗效果。我们开发了和 测试了可生物降解的聚乳酸-乙醇酸(PLGA)微球的局部抗生素递送系统 保留了PMMA抗生素输送的优点，但不需要移除。一种新兴的治疗策略 MDR感染是通过静脉注射噬菌体直接靶向和溶解细菌病原体 (杀死细菌的病毒)或‘噬菌体’。噬菌体在感染部位自我复制，不共享抗性 抗生素的作用机制，甚至可能恢复细菌对抗生素的敏感性。作为IV噬菌体 给药有缺点，包括在运送过程中损失噬菌体，以及长期接触 免疫系统，我们在这里提出了一种创新的纳米技术战略，使用我们的生物可降解递送 局部给药裂解噬菌体治疗ODRI的系统。 我们最近证明了噬菌体K，它有效地裂解了许多金黄色葡萄球菌， 引起ODRI的最常见的原因是可以被结合到PLGA微球中。此外，洗脱的噬菌体是 能够在骨科材料的体外生物膜内杀死金黄色葡萄球菌。我们的长期目标是发展有效的 局部应用裂解噬菌体治疗耐多药耐药相关感染。我们计划了以下短期目标：1)优化噬菌体 掺入PLGA微球，2)产生裂解噬菌体鸡尾酒来治疗金黄色葡萄球菌，消除 3)优化后的含噬菌体微球的体外细胞培养和 在体大鼠ODRI模型的建立。预计本申请书中提议的调查将为 利用局部释放的裂解噬菌体治疗ODRI感染从而改善患者的临床试验方法 结果。

ABATRACT: Osteomyelitis due to orthopaedic device-related infections (ODRIs), is a major complication in orthopaedic medicine, resulting in approximately 200,000 cases in the US per year (~3% of the estimated 6 million elective orthopaedic surgeries), and is predicted to rise as the US population ages. Current treatment requires 4 to 6 weeks of IV antibiotic administration and multiple surgeries to remove the infected implants and surrounding tissue and restore the device, resulting in a large economic burden and significant patient morbidity. ODRIs are extremely recalcitrant to antibiotic treatment as these are biofilm infections, in which the bacterial pathogens are attached to surfaces surrounded by a self-produced matrix. A hallmark of biofilms is their resistance to antibiotics and the host immune system. Furthermore, antibiotics administered orally or parenterally (intravenously or through intramuscular injection) have poor bone penetration. Another treatment complication is the rise in ODRIs due to antibiotic- and multidrug-resistant (MDR) bacteria. Local delivery of antibiotics by their incorporation into polymethylmethacrylate (PMMA) beads has improved treatment. We developed and tested a local antibiotic delivery system of biodegradable poly(lactic-co-glycolic acid) (PLGA) microspheres that retain the advantages of PMMA antibiotic delivery, but do not require removal. An emerging strategy to treat MDR infections is to directly target and lyse the bacterial pathogen using IV administration of bacteriophage (viruses that kill bacteria) or `phage'. Phage self-replicate at the site of infection, do not share resistance mechanisms with antibiotics, and may even restore bacterial susceptibility to antibiotics. As IV phage administration has drawbacks including the loss of phage during delivery and long-term exposure to the immune system, we propose here an innovative nanotechnology strategy using our biodegradable delivery system to locally administer lytic phage to treat ODRIs. We have recently demonstrated that phage K, which effectively lyses many strains of Staphylococcus aureus, the most common cause of ODRIs, can be incorporated into PLGA microspheres. Further, eluted phage are able to kill S. aureus within in vitro biofilms on orthopaedic materials. Our long-term goal is to develop effective local delivery of lytic phage to treat MDR ODRIs. We plan the following short-term goals: 1) optimize the phage incorporation into PLGA microspheres, 2) generate lytic phage cocktails to treat S. aureus ODRI that eliminate bacterial phage resistance, 3) test of the optimized phage-containing microspheres in in-vitro cell culture and an in-vivo rat model of ODRI. It is anticipated that the investigations proposed in this application will pave the way for clinical trials using local delivery of lytic phage to treat ODRI infections thereby improving patient outcomes.