A Comprehensive In Vitro Assessment of Broad-Spectrum Antimicrobial Efficacy of Organo-Selenium-Incorporated Urinary Catheter in Comparison to a Zwitterionic Surface Catheter

Background/Objectives: Catheter-associated urinary tract infections (CAUTIs) are one of the most common healthcare-related morbidities. Also, severe clinical outcomes derived from CAUTIs demand an urgent need for the development of novel antimicrobial catheter materials. Since CAUTIs are primarily driven by a wide range of microorganisms causing biofilm formation on the surfaces of catheters, evaluating the effectiveness of innovative antimicrobial materials against a broad spectrum of known uropathogens is warranted. We aim (1) to demonstrate the ability of incorporated organo-selenium versus that of an FDA-cleared antimicrobial catheter and (2) to show that the results of the study are consistent against the most common microorganisms causing urinary tract infections in humans. Methods: Based on encouraging preliminary studies, three percent of organo-selenium (weight-based), as a novel antimicrobial catheter material, was incorporated into thermoplastic polyurethane (TPU). This was compared in vitro with plain polyurethane catheters and the SILQ ClearTract catheter with a zwitterionic coating (FDA-cleared for its antimicrobial properties in December 2022). The antimicrobial activity was studied against Candida albicans, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus, MRSA, and Staphylococcus epidermidis by assessment of colony-forming unit counts along with visual confirmation using Scanning Electron Microscopy (SEM). Results: Plain polyurethane catheters (control group) showed 7- to 8-log of in vitro growth for all tested microbes, whereas the antimicrobial zwitterionic SILQ ClearTract catheters still showed 6- to 7-log of microbial growth. In contrast, organo-selenium-incorporated catheters demonstrated no detectable in vitro growth for all tested microbes (C. albicans, E. coli, K. pneumoniae, P. mirabilis, P. aeruginosa, S. aureus, MRSA, and S. epidermidis). SEM analysis also validated the findings. Conclusions: Potentially non-leaching organo-selenium, as a novel urinary catheter material, significantly inhibited microbial attachment, growth, and biofilm formation across a wide spectrum of common uropathogenic organisms compared to a zwitterionic catheter, providing a strong foundation for further detailed in vivo and clinical studies.