Division of Infectious Diseases, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
FEMS Microbiol Lett. 2013 Jan;338(1):24-30. doi: 10.1111/1574-6968.12018. Epub 2012 Nov 2.
Staphylococcus epidermidis infections are common complications of prosthetic device implantation. SdrF, a surface protein, appears to play a critical role in the initial colonization step by adhering to type I collagen and Dacron™. The role of ionic interactions in S. epidermidis adherence to prosthetic material was examined. SdrF was cloned and expressed in Lactococcus lactis. The effect of pH, cation concentration, and detergents on adherence to different types of plastic surfaces was assessed by crystal violet staining and bacterial cell counting. SdrF, in contrast with controls and other S. epidermidis surface proteins, bound to hydrophobic materials such as polystyrene. Binding was an ionic interaction and was affected by surface charge of the plastic, pH, and cation concentration. Adherence of the SdrF construct was increased to positively charged plastics and was reduced by increasing concentrations of Ca(2+) and Na(+). Binding was optimal at pH 7.4. Kinetic studies demonstrated that the SdrF B domain as well as one of the B subdomains was sufficient to mediate binding. The SdrF construct also bound more avidly to Goretex™ than the lacotococcal control. SdrF is a multifunctional protein that contributes to prosthetic devices infections by ionic, as well as specific receptor-ligand interactions.
表皮葡萄球菌感染是人工植入装置的常见并发症。表面蛋白 SdrF 似乎通过黏附 I 型胶原蛋白和 Dacron™在初始定植步骤中发挥关键作用。本研究旨在研究离子相互作用在表皮葡萄球菌黏附人工材料中的作用。将 SdrF 克隆并在乳球菌中表达。通过结晶紫染色和细菌细胞计数评估 pH、阳离子浓度和去污剂对不同类型塑料表面黏附的影响。与对照和其他表皮葡萄球菌表面蛋白相比，SdrF 与疏水性材料（如聚苯乙烯）结合。结合是一种离子相互作用，受塑料表面电荷、pH 和阳离子浓度的影响。SdrF 构建体的黏附作用增加到带正电荷的塑料上，并通过增加 Ca(2+)和 Na(+)的浓度而降低。最佳结合 pH 值为 7.4。动力学研究表明，SdrF B 结构域和 B 亚结构域之一足以介导结合。SdrF 构建体与 Goretex™的结合也比乳球菌对照更紧密。SdrF 是一种多功能蛋白，通过离子和特定受体-配体相互作用，有助于人工植入物感染。
