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 selleck 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 Ca2+ 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. Infections are among the most common complications of prosthetic device implantation (Baddour et al., 2003; Gandelman et al., 2007; Wang et al., 2007). The capacity of bacteria to adhere to these devices through both specific and nonspecific interactions is a critical first step in the initiation of these infections (Broekhuizen buy Thiazovivin et al., 2006; Tsapikouni et al., 2008; Otto, 2009). This problem is enhanced when the infection involves devices such as ventricular assist devices that are critical to patient survival (Rose et al., 2001). Infections Farnesyltransferase involving these devices occur in 15–30% of patients and generally
require either device removal or transplantation to affect a cure (Herrmann et al., 1997; Holman et al., 1997; Gordon et al., 2006) [INTERMACS (http://www.intermacs.org)]. Staphylococcus epidermidis remains the most common cause of prosthetic device-related infections (Simon et al., 2005; Gordon et al., 2006). As part of the commensal skin flora, staphylococci are uniquely situated to contaminate wounds when cutaneous barriers are breached. Surface proteins known as microbial surface components recognizing adhesive matrix molecules facilitate the initial colonization step (Patti et al., 1994; MacKintosh et al., 2006; Otto, 2009). SdrF, a S. epidermidis surface protein, appears to contribute to the initiation of prosthetic device infections. Previous studies showed that SdrF, a member of the serine–aspartate (SD) family of surface proteins, binds type I collagen and mediates adhesion of S. epidermidis to the ventricular assisted device (VAD) driveline (Bowden et al., 2005; Arrecubieta et al., 2007, 2009).