Department of Chemical Engineering, University of Louisville, 216 Eastern Pkwy, Louisville, Kentucky 40208.
Biointerphases. 2024 Sep 1;19(5). doi: 10.1116/6.0003870.
Staphylococcus aureus (S. aureus) is a potentially pathogenic bacterium that commonly colonizes surfaces through the formation of biofilms. Silica glass is a common material in the built environment, especially in laboratory and medical spaces. The chemical and physical mechanisms by which S. aureus initially adheres to surfaces are unclear. In this study, the adsorption of several S. aureus biofilm associated compounds on silica is probed using molecular dynamics simulations. Model compounds containing a phosphorylated backbone, N-acetylglucosamine (GlcNAc), or D-alanine (D-Ala) were simulated across a range of pH. GlcNAc adsorption is unfavorable and insensitive to pH. D-Ala adsorption is unfavorable across the range of tested pH. Phosphorylated backbone adsorption is unfavorable at low pH but favorable at high pH. Adsorbate titration and solution salt concentration were probed to establish effects of molecular charge and charge screening. Hydrogen bonding between compounds and the silica surface is a key factor for stronger adsorption. The findings of this study are important for the rational design of improved silica surfaces through chemical functionalization or through the application of optimal chemical disinfectants that discourage the initial stages of biofilm growth.
金黄色葡萄球菌（S. aureus）是一种潜在的致病细菌，通常通过形成生物膜在表面定殖。二氧化硅玻璃是建筑环境中的常见材料，尤其是在实验室和医疗空间中。金黄色葡萄球菌最初附着在表面的化学和物理机制尚不清楚。在这项研究中，使用分子动力学模拟研究了几种与金黄色葡萄球菌生物膜相关的化合物在二氧化硅上的吸附。模拟了一系列 pH 值下含有磷酸化主链、N-乙酰葡萄糖胺（GlcNAc）或 D-丙氨酸（D-Ala）的模型化合物。GlcNAc 的吸附是不利的，并且对 pH 不敏感。D-Ala 的吸附在测试的 pH 范围内是不利的。磷酸化主链在低 pH 值下吸附不利，但在高 pH 值下吸附有利。通过吸附剂滴定和溶液盐浓度来探究分子电荷和电荷屏蔽的影响。化合物与二氧化硅表面之间的氢键是吸附增强的关键因素。这项研究的结果对于通过化学功能化设计改进的二氧化硅表面或通过应用最佳的化学消毒剂来抑制生物膜生长的初始阶段非常重要。
