Micropatterned surfaces for reducing the risk of catheter-associated urinary tract infection: an in vitro study on the effect of sharklet micropatterned surfaces to inhibit bacterial colonization and migration of uropathogenic Escherichia coli.

BACKGROUND AND PURPOSE Catheter-associated urinary tract infection (CAUTI) is the most common device-associated infection and can result in serious medical consequences. We studied the efficacy of a novel microscopic physical surface modification (Sharklet) for preventing bacterial colonization and migration of uropathogenic Escherichia coli on silicone elastomer. MATERIALS AND METHODS In vitro growth assays evaluated E coli colonization using three variations of micropatterned silicone surfaces vs a smooth silicone control. Enumeration techniques included quantification of colonies on surfaces and analysis of bacterial area coverage and colony size. In vitro migration assays involved placement of micropatterned and smooth silicone rod segments between two agar islands to measure incidence of migration. RESULTS All three variations of the Sharklet micropattern outperformed the control surfaces in inhibiting E coli colonization. On average, 47% reduction in colony-forming units (CFUs) and bacterial area coverage plus 77% reduction in colony size were achieved with the Sharklet surfaces in tryptic soy broth and artificial urine compared with the control nonpatterned surfaces. The incidence of E coli migration over the rod segments was reduced by more than 80% for the Sharklet transverse patterned rods compared with the unpatterned control rods. CONCLUSION The Sharklet micropattern is effective at inhibiting colonization and migration of a common uropathogen. This performance is achieved through a physical surface modification without the use of any antimicrobial agents. Because deterrence of bacterial colonization and migration is a critical step to prevent CAUTI, the Sharklet micropattern offers a novel concept in addressing this important problem.