The Influence of Urinary Catheter Materials on Forming Biofilms of Microorganisms

Biofilms are commonly associated with an increased risk of catheter-associated infection. To study the efficacy of materials designed to reduce biofilm formation, microbial biofilms on clinically used urinary catheter were examined. We performed 2, 3-bis (2-methyoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay to determine of biofilm formation ability and observed with scanning electron microscopy (SEM) to analyze biofilm architecture. Additionally, we calculated relative cell surface hydrophobicity (CSH) to measure hydrophobicity of microorganisms. On SEM, catheter surfaces made of latex or anti-infective (IC)-latex were rough but those of silicone, hydrogel-coated silicone (HCS), or silver-alloy-coated silicone (SCS) were relatively smoother. According to XTT reduction assay, biofilm formation was reduced on the surface of smooth silicone-based catheters compared to rough latex-based catheters. The greatest to lowest formation of microbial biofilm were as follows for these material types: silicone-elastomer- coated (SEC) latex > latex > silicone > IC-latex > HCS > SCS. Catheter materials can affect the microbial biofilm formations. First, rougher surfaces on the catheter made the microbial attachment easier and a greater amount of biofilm was formed. Second, when chemicals that inhibit growth and attachment of microorganisms on the inner and outer surfaces of the catheters were applied, the biofilm formation was inhibited. SCS was found to be the most effective in reducing the microbial biofilm formation. These results indicate that microbial biofilm formation may be closely related to the surface roughness and microbial CSH.