Novel antiseptic urinary catheters for prevention of urinary tract infections: correlation of in vivo and in vitro test results

Abstract

Urinary catheters are widely used for hospitalized patients and are often associated with high rates of urinary tract infection. We evaluated in vitro the antiadherence activity of a novel antiseptic Gendine-coated urinary catheter against several multidrug-resistant bacteria. Gendine-coated urinary catheters were compared to silver hydrogel-coated Foley catheters and uncoated catheters. Bacterial biofilm formation was assessed by quantitative culture and scanning electron microscopy. These data were further correlated to an in vivo rabbit model. We challenged 31 rabbits daily for 4 days by inoculating the urethral meatus with 1.0 x 10(9) CFU streptomycin-resistant Escherichia coli per day. In vitro, Gendine-coated urinary catheters reduced the CFU of all organisms tested for biofilm adherence compared with uncoated and silver hydrogel-coated catheters (P < 0.004). Scanning electron microscopy analysis showed that a thick biofilm overlaid the control catheter and the silver hydrogel-coated catheters but not the Gendine-coated urinary catheter. Similar results were found with the rabbit model. Bacteriuria was present in 60% of rabbits with uncoated catheters and 71% of those with silver hydrogel-coated catheters (P < 0.01) but not in those with Gendine-coated urinary catheters. No rabbits with Gendine-coated urinary catheters had invasive bladder infections. Histopathologic assessment revealed no differences in toxicity or staining. Gendine-coated urinary catheters were more efficacious in preventing catheter-associated colonization and urinary tract infections than were silver hydrogel-coated Foley catheters and uncoated catheters.

FIG. 1.

SEM of bacterial biofilms grown on coated and uncoated urinary catheters. (A) VRE on an uncoated catheter. VRE cells are present on the surface, with a biofilm matrix (arrows) seen at some spots covering the cells. (B) VRE on a silver hydrogel-coated catheter. Organisms are covered with an extensive biofilm, where the biofilm matrix looks like a granular structure with bacterial cells totally embedded within it. (C) VRE on a GND-UC. The GND-UC resulted in a reduction in biofilm, and no organisms as seen in panels A and B are visible in panel C. Magnification, ×5,000.