Effect of pre-adsorbed serum albumin on the interaction between Pseudomonas aeruginosa and material surfaces

When a biomedical device is implanted into the body, its surface initially encounters biological fluids, resulting in the natural adsorption of various host proteins. This protein-adsorbed layer significantly alters the inherent properties of the biomaterial surface and may play a crucial role in interactions between the implant and bacteria. Here we investigated the influence of an adsorbed layer of albumin, the predominant plasma protein, on the adhesion and biofilm formation of three different bacterial strains: Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa. We showed that the effect of a serum albumin layer on bacterial adhesion was strain-dependent. While pre-adsorption of albumin reduced the initial adhesion of S. aureus and S. epidermidis on the PDMS surface, no impact was observed on the adhesion of P. aeruginosa. In contrast, the albumin-adsorbed surface significantly increased the density of adhered P. aeruginosa for extended incubation time. The proteomic analysis highlighted significant physiological changes in P. aeruginosa when exposed to an albumin-adsorbed surface compared to a control surface. These changes are particularly related to the molecular pathways involved in surface colonization, such as quorum sensing, bacterial motility, adhesion factors, and biofilm formation. These findings suggest that serum albumin adsorption not only affects the initial interaction between bacteria and the surface but also alters the bacteria's adaptive behavior on the biomaterial surface. This study provides a deeper understanding of the complex bacteria-surface interactions, contributing to the development of future strategies for preventing implant-associated infections

当生物医学装置植入体内后，其表面首先会接触生物体液，进而发生多种宿主蛋白的自然吸附现象。这层蛋白吸附层会显著改变生物材料表面的固有属性，并可能在植入物与细菌的相互作用中发挥关键作用。本研究探讨了作为主要血浆蛋白的白蛋白（albumin）吸附层对三种不同细菌菌株——金黄色葡萄球菌（Staphylococcus aureus）、表皮葡萄球菌（Staphylococcus epidermidis）以及铜绿假单胞菌（Pseudomonas aeruginosa）——的黏附与生物膜形成的影响。研究结果表明，血清白蛋白层对细菌黏附的影响具有菌株依赖性：白蛋白预吸附可降低金黄色葡萄球菌与表皮葡萄球菌在聚二甲基硅氧烷（PDMS）表面的初始黏附能力，但对铜绿假单胞菌的黏附无显著影响。与之相反，经白蛋白吸附处理的表面在延长培养时间后，会显著提高黏附的铜绿假单胞菌密度。蛋白质组学分析显示，与对照表面相比，铜绿假单胞菌在接触白蛋白吸附表面时会发生显著的生理变化，这些变化尤其与表面定殖相关的分子通路有关，包括群体感应（quorum sensing）、细菌运动力、黏附因子以及生物膜形成相关通路。上述研究结果表明，血清白蛋白吸附不仅会影响细菌与表面的初始相互作用，还会改变细菌在生物材料表面的适应行为。本研究加深了我们对复杂的细菌-表面相互作用的理解，可为未来预防植入物相关感染的策略开发提供参考。