DECREASED BACTERIAL ADHERENCE AND BIOFILM FORMATION ON CHLORHEXIDINE AND SILVER SULFADIAZINE-IMPREGNATED CENTRAL VENOUS CATHETERS IMPLANTEDIN SWINE

Objective: To determine if antiseptic central venous catheters impregn ated with silver sulfadiazine and chlorhexidine (antiseptic) reduce ba cterial adherence and biofilm formation without producing local or sys temic toxicity. Design: Prospective, randomized, controlled trial. Set ting: Experimental laboratory in a university teaching hospital. Subje cts: Ten outbred New Hampshire pigs. Interventions: Nonimpregnated (co ntrol) and antiseptic-impregnated catheters were inserted intravascula rly into swine for 7 days. After explantation, the catheters were asse ssed for bacterial adherence and biofilm formation, and the surroundin g tissue was assessed for signs of toxicity. Before retrieval, systemi c concentrations of antimicrobials were determined. Measurements and M ain Results: Sequential roll plate and centrifuging were used to detec t moderately and tightly adherent bacteria on the outer and luminal su rfaces of the catheter. The presence of biofilm was detected by scanni ng electron microscopy. Tissues surrounding the catheters were examine d histopathologically; systemic concentrations of chlorhexidine, sulfa diazine, and silver were determined by atomic absorption and high-perf ormance Liquid chromatography. As compared with the controls, antisept ic catheters had significantly (p < .01) fewer moderately and tightly adherent bacteria on outer and luminal surfaces, and fewer adherent ba cteria when outer surfaces alone were examined (p < .01). Scanning ele ctron microscopy showed bacterial biofilm and adherence on the control catheters but not on the antiseptic catheters. There were no abnormal histopathologic changes associated with the test catheter, and serum concentrations of the antibacterial agents were shown to be within non -toxic ranges. Conclusion: The antiseptic-impregnated catheters preven ted bacterial adherence and biofilm formation and produced no local or systemic toxicity.