Polymicrobial biofilms are major complications of various chronic infections. Therefore, in vitro biorelevant polymicrobial biofilm models are essential tools for medical studies. This study presents an in vitro model for dual species biofilm of Pseudomonas aeruginosa and Staphylococcus aureus developed on cell-derived matrices (CDMs), in order to simulate the microenvironment of in vivo biofilms. P. aeruginosa and S. aureus are two of the most frequent pathogens in polymicrobial biofilms of wound infections. Although they are commonly isolated from polymicrobial biofilms, their interaction is antagonistic; and there is severe battle between them for nutrients and space. We introduced a nutritious formulation supporting co-cultures of P. aeruginosa and S. aureus in order to study the interaction of these gram-positive and gram-negative bacterial species. Quantitative analyses demonstrated that the enrichment of tryptic soy broth (TSB) with NaCl and glucose facilitate dual-species biofilm formation of P. aeruginosa and S. aureus when it is mixed with fetal bovine serum (FBS). Furthermore, the dual species biofilm was incubated on CDMs. Characterization of the model by fluorescent and electron microscopy techniques revealed realistic features of chronic multi-species biofilms, including competitive distribution pattern of two bacterial species and small-colony variants (SCVs) morphology of S. aureus.

微生物生物膜是各种慢性感染的主要并发症。因此，体外生物相关的微生物生物膜模型是医学研究必不可少的工具。这项研究提出了一种在细胞衍生基质（CDM）上开发的铜绿假单胞菌和金黄色葡萄球菌双物种生物膜的体外模型，以模拟体内生物膜的微环境。铜绿假单胞菌和金黄色葡萄球菌是伤口感染的多菌种生物膜中最常见的两种病原体。尽管它们通常是从微生物生物膜中分离出来的，但它们之间的相互作用却具有拮抗作用。他们之间在营养和空间方面进行了激烈的战斗。为了研究这些革兰氏阳性菌和革兰氏阴性菌之间的相互作用，我们引入了一种营养配方，支持铜绿假单胞菌和金黄色葡萄球菌的共培养。定量分析表明，富含氯化钠和葡萄糖的胰蛋白酶大豆肉汤（TSB）促进铜绿假单胞菌和金黄色葡萄球菌的双物种生物膜形成。当与胎牛血清（FBS）混合时。此外，将双物种生物膜在CDM上孵育。通过荧光和电子显微镜技术对该模型进行表征，揭示了慢性多物种生物膜的现实特征，包括两种细菌物种的竞争性分布模式以及金黄色葡萄球菌的小菌落变体（SCV）形态。