Chronic wounds will impact 2% of the United States population at some point in their life. These wounds are often associated with a reoccurring, chronic infection caused by a community of microorganisms encased in an extracellular polymeric substance (EPS), or a biofilm. Biofilm-associated microbes can exhibit tolerance to antibiotics, which has prompted researchers to investigate therapeutics that improve antibiotic efficacy. Glycoside hydrolases (GHs), enzymes that target the polysaccharide linkages within the EPS, are one potential adjunctive therapy. In order to develop GH-based therapeutics, it is imperative that we understand whether the composition of biofilm EPS changes based on the environment and/or presence of other microbes. Here, we utilized α-amylase and cellulase to target the polysaccharides within the EPS of mono- and dual-species Pseudomonas aeruginosa and Staphylococcus aureus biofilms in three different models that vary in clinical relevancy. We show that biofilms established in an in vitro well-plate model are not strongly adhered to the polystyrene surface and do not accurately reflect the GH efficacy seen with biofilms grown in vivo. However, dispersal efficacy in an in vitro wound microcosm model was more reflective of that seen in a murine wound model. We also saw a striking loss of efficacy for cellulase to disperse S. aureus in both mono- and dual species biofilms grown in the wound models, suggesting that EPS constituents may be altered depending on the environment.

慢性伤口将在他们生命的某个阶段影响 2% 的美国人口。这些伤口通常与由包裹在细胞外聚合物 (EPS) 或生物膜中的微生物群落引起的复发性慢性感染有关。生物膜相关微生物可以表现出对抗生素的耐受性，这促使研究人员研究提高抗生素疗效的治疗方法。糖苷水解酶 (GHs) 是一种靶向 EPS 内多糖键的酶，是一种潜在的辅助疗法。为了开发基于 GH 的疗法，我们必须了解生物膜 EPS 的组成是否会根据环境和/或其他微生物的存在而变化。在这里，我们利用α-淀粉酶和纤维素酶来靶向单物种和双物种 EPS 中的多糖铜绿假单胞菌和金黄色葡萄球菌三种不同模型中的生物膜在临床相关性上有所不同。我们表明，生物膜建立在体外孔板模型没有牢固地粘附在聚苯乙烯表面，也不能准确反映生长的生物膜所见的 GH 功效体内. 然而，分散效果在体外伤口缩影模型更能反映小鼠伤口模型中的情况。我们还发现纤维素酶分散的功效显着下降金黄色葡萄球菌在伤口模型中生长的单物种和双物种生物膜中，表明 EPS 成分可能会根据环境而改变。