Evaluation of the Antimicrobial Efficacy of Urinary Catheters Impregnated With Antiseptics in an In Vitro Urinary Tract Model

Abstract

Objectives: : To evaluate the long-term efficacy of urinary Foley catheters (latex and silicone) impregnated with (1) chlorhexidine and silver sulfadiazine (CXS) and (2) chlorhexidine, silver sulfadiazine, and triclosan (CXST) in inhibiting extra-luminal bacterial adherence and to compare their efficacy with that of silver hydrogel latex (SH) and nitrofurazone-treated silicone (NF) catheters.Design: : The antimicrobial spectrum of these catheters was evaluated using a zone of inhibition assay. A novel in vitro urinary tract model was developed to study the potential in vivo efficacy of antimicrobial catheters in preventing extraluminal bacterial colonization. The “meatus” was inoculated daily withStaphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa,andCandida albicans. The “bladder” portion of the model was cultured daily to determine bacterial growth.Results: : Both CXS and CXST catheters had a broader antimicrobial spectrum than SH and NF catheters. In the in vitro model, CXST latex and silicone catheters exhibited significantly better efficacy (3 to 25 days) against uropathogens, compared with CXS (1 to 14 days) and control (0 to 5 days) catheters (P= .01). CXST latex catheters exhibited significantly longer protection againstStaphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, andPseudomonas aeruginosa, compared with SH catheters (P= .01). CXST silicone catheters resisted colonization withStaphylococcus aureusandStaphylococcus epidermidisfor a significantly longer period (23 to 24 days) than did NF catheters (9 to 11 days) (P= .01).Conclusion: : Catheters impregnated with synergistic combinations of chlorhexidine, silver sulfadiazine, and triclosan exhibited broad-spectrum, long-term resistance against microbial colonization on their outer surfaces (Infect Control Hosp Epidemiol2003;24:506-513)