Background: Central venous catheters (CVCs) are responsible for approximately 90% of all catheter-related bloodstream infections (CRBSIs). These CRBSIs, commonly caused by Staphylococcus aureus and Staphylococcus epidermidis, are associated with 28,000 deaths per year in the U.S. as well as prolonged hospital stays and increased healthcare costs. A common strategy used to prevent CRBSIs has been to impregnate CVCs with antimicrobial agents, which can be limited by the short duration of efficacy and the potential for contributing to antimicrobial resistance. A novel micro-topography may provide an alternative strategy as it has been shown to reduce bacterial attachment and biofilm formation without the use of antimicrobial agents. This micro-pattern also inhibits bacterial migration, offering the possibility of reducing bacterial access into the bloodstream via the CVC. The objective of this study was to determine the performance of the Sharklet micro-pattern in reducing S. aureus attachment to samples made in the same material as CVCs after whole blood pre-conditioning.
Methods: Patterned and un-patterned (control) thermoplastic polyurethane samples (n=4) were immersed statically in either whole blood or saline for 2 hours at 37°C, followed by a saline rinse, and inoculation with ~107 CFU/mL S. aureus (ATCC6538) in saline. The samples were incubated statically for 1 and 16 hours at 37°C before rinsing with saline and enumerating the attached cells by ultrasonication and dilution plating. Statistical analysis was conducted through t-test and ANOVA models.
Results: After preconditioning surfaces with blood, the micro-patterned surfaces reduced S. aureus colonization to a clinically relevant material by 65% (p≤0.05) after 1hr and 70% (p≤0.05) after 16hrs when compared to preconditioned un-patterned surfaces. There was no significant difference in micro-patterned surface performance across time points and preconditioning fluids (i.e. blood vs. saline).
Conclusion: The surface modification afforded by the micro-texture significantly inhibits the colonization of S. aureus after blood preconditioning on a clinically relevant material. Introduction of this micro-pattern on central venous catheters may be useful for controlling CRBSIs.