535. Uropathogen Adherence to Silver- and Nitrofurazone-coated Urinary Catheters
Session: Poster Session: Hospital-acquired and Transplant Infections
Friday, October 30, 2009: 12:00 AM
Room: Poster Hall A
Background: Although silver- and nitrofurazone-impregnated urinary catheters are used to decrease rates of catheter-associated urinary tract infections, little published data describe the adherence of bacteria to these catheters. We studied in vitro the degree and durability of the anti-adherence effect of antimicrobial impregnation on 2 common urinary pathogens, Escherichia coli and Enterococcus faecalis.
Methods: Antimicrobial catheters (nitrofuranzone silicone, silver silicone hydrogel, silver latex) and control catheters (silicone, silicone hydrogel, and latex) were cut into 1 cm segments and placed in 50 ml of Luria Bertani media. The media was changed daily for 10 days. Catheter segments were removed and inoculated on days 1, 3, 5, 7, and 10 then incubated 24 hours at 37°C. The catheters were then rinsed, sonicated, and plated to determine the numbers of adherent pathogens.
Results: Bacterial adherence to silver-impregnated catheters did not differ from adherence to control catheters even after 0 days of prior incubation in liquid media. Adhesion of E. coli to nitrofurazone catheters was less than to control catheters even after 10 days of incubation in liquid media prior to exposure to the pathogen. This difference remained statistically significant through 5 days (p<0.05, T Test). For Enterococcus, there was decreased adherence to nitrofurazone catheters at 0 days of prior incubation in media (p<0.001), but this difference disappeared after 3 days of prior incubation. When comparing adherence of both uropathogens to silicone, silicone hydrogel, and silicone silver hydrogel catheters, no additional effect on adherence was noted with the addition of silver.
Conclusion: Hydrogel significantly decreased bacterial adherence to catheters but silver impregnation did not. Nitrofurazone catheters inhibited bacterial adhesion; however, this effect was lost after 5 days in liquid media. These results are in accord with clinical data suggesting nitrofurazone catheters have a transient effect on bacterial adhesion up to 1 week. Our findings do not support use of silver catheters.
Manuel Cevallos, MD, Baylor College of Medicine, Devak Desai, MD, Barbara W. Trautner, MD, PhD, Health Services Research & Development Center of Excellence, Michael E. DeBakey Veterans Affairs Medical Center, Houston, TX and  D. G. Desai, None..
M. E. Cevallos, None..
B. W. Trautner, None.