Biofilm matrix-degrading enzymes for the treatment and prevention of S. aureus-as

描述(由申请人提供)：伤口感染是一个主要的医学问题。定植在伤口上的细菌会推迟伤口愈合，并成为继发性感染的焦点。此外，使用抗生素治疗伤口感染导致抗药性菌株的快速演变，这进一步使治疗变得复杂。伤口感染对卫生资源和成本有重大影响。定植在伤口上的细菌形成了被称为生物膜的多细胞附着群落。生物膜中的细胞产生一种细胞外聚合物基质，将细胞聚集在一起，并将细菌团牢固地附着在受伤的组织上。生物膜基质固有的保护性使伤口感染难以治疗。大多数生物膜的细胞外基质含有多糖和DNA等聚合物。降解生物膜基质聚合物的酶已被证明在体外可以抑制生物膜的形成，分离预先形成的生物膜，并使预先形成的生物膜对抗生素和局部杀生剂的杀灭敏感。我们的中心假设是，基质降解酶将是预防和治疗伤口感染的有用外用药物。本提案的目的是测量两种生物膜基质降解酶DispersinB(R)(糖苷水解酶)和Pulmozyme(R)(DNase I)的体内抗生物被膜活性。本研究的目的是回答以下问题：(1)基质降解酶是否增强了局部杀生剂消除非创面细菌定植的能力？(2)基质降解酶是否增强了局部杀生剂对新鲜污染的全层伤口进行净化的能力？(3)基质降解酶是否增强了脉冲冲洗治疗对新鲜污染的全层伤口进行净化的能力？研究将使用猪皮肤定植和伤口污染模型进行。所有实验都将使用常见的伤口病原体金黄色葡萄球菌进行。局部杀菌剂将包括聚维酮碘和葡萄糖酸氯己定。对于皮肤定植模型，主要结果将是CFU/cm2；对于伤口污染模型，主要结果将是CFU/伤口。拟议的实验有望导致基于酶的局部伤口护理配方的开发，以供人体临床试验测试。使用酶来破坏生物膜基质的物理完整性是一种有吸引力的伤口治疗策略，因为它可以减少或消除对传统抗生素的需求。项目描述细菌感染是伤口损伤的严重并发症。研究表明，在受感染的伤口中生长的细菌被一层称为粘液层的粘性物质所包围。在这个项目中，我们计划测试粘液降解酶是否可以用于治疗和预防猪的伤口感染。如果成功，这些粘液降解酶将被合并到一种局部软膏中，可用于治疗和预防人体伤口感染。 公共卫生相关性：细菌感染是伤口损伤的严重并发症。研究表明，在受感染的伤口中生长的细菌被一层称为粘液层的粘性物质所包围。在这个项目中，我们计划测试粘液降解酶是否可以用于治疗和预防猪的伤口感染。如果成功，这些粘液降解酶将被合并到一种局部软膏中，可用于治疗和预防人体伤口感染。

DESCRIPTION (provided by applicant): Wound infections are a major medical problem. Bacteria that colonize wounds can delay wound healing and act as a focus for secondary infections. In addition, the use of antibiotics to treat wound infections results in the rapid evolution of antibiotic-resistant strains, which further complicates treatment. Wound infections have a significant impact on health resources and costs. Bacteria that colonize wounds form adherent, multicellular communities known as biofilms. The cells in a biofilm produce an extracellular polymeric matrix that holds the cells together in a mass and firmly attaches the bacterial mass to the wounded tissue. The inherent protective nature of the biofilm matrix makes wound infections difficult to treat. The extracellular matrix of most biofilms contains polymers such as polysaccharides and DNA. Enzymes that degrade biofilm matrix polymers have been shown to inhibit biofilm formation, detach pre-formed biofilms, and sensitize pre-formed biofilms to killing by antibiotics and topical biocides in vitro. Our central hypothesis is that matrix-degrading enzymes will be useful topical agents for the prophylaxis and treatment of wound infections. The objective of the present proposal is to measure the in vivo anti-biofilm activities of two biofilm matrix-degrading enzymes, DispersinB(R) (a glycoside hydrolase) and Pulmozyme(R) (DNase I). The aims of this study are to answer the following questions: (1) Do matrix-degrading enzymes potentiate the ability of topical biocides to eradicate bacterial colonization of non-wounded skin? (2) Do matrix-degrading enzymes potentiate the ability of topical biocides to decontaminate freshly contaminated full-thickness wounds? (3) Do matrix-degrading enzymes potentiate the ability of pulse irrigation treatment to decontaminate freshly contaminated full-thickness wounds? Studies will be carried out using porcine skin colonization and wound contamination models. All experiments will be carried out using the common wound pathogen Staphylococcus aureus. Topical biocides will include povidone iodine and chlorhexidine gluconate. Major outcomes will be CFU/cm2 for skin colonization models and CFU/wound for wound contamination models. The proposed experiments are expected to lead to the development of enzyme-based topical wound care formulations for testing in human clinical trials. The use of enzymes to destroy the physical integrity of the biofilm matrix is an attractive wound treatment strategy because it may reduce or eliminate the need for conventional antibiotics. Project Narrative Bacterial infections are a serious complication of wound injuries. Studies have shown that bacteria growing in infected wounds are surrounded by a layer of sticky material that is referred to as the slime layer. In this project we plan to test whether slime-degrading enzymes can be used to treat and prevent wound infections in pigs. If successful, these slime-degrading enzymes will be incorporated into a topical ointment that can be used to treat and prevent wound infections in people. PUBLIC HEALTH RELEVANCE: Bacterial infections are a serious complication of wound injuries. Studies have shown that bacteria growing in infected wounds are surrounded by a layer of sticky material that is referred to as the slime layer. In this project we plan to test whether slime-degrading enzymes can be used to treat and prevent wound infections in pigs. If successful, these slime-degrading enzymes will be incorporated into a topical ointment that can be used to treat and prevent wound infections in people.