Antimicrobial activity of polymers-functionalized urinary catheters against Staphylococcus aureus

Introduction: Approximately 40% of nosocomial infections are catheter-associated urinary tract infections. Various surface modification methods are under consideration, with the potential to prevent bacterial colonization on the urinary catheter (UC). Objectives: Herein, we aimed to coat the UC with a coating of polyvinyl alcohol (PVA) and ε-polylysine (PLL) and to check their antimicrobial effects against Staphylococcus aureus. Methodology: A 10% PVA solution was prepared by mixing 10g of PVA in 90 ml deionized water and stirring at 90 °C for two hours. Subsequently, 0.15 ml of 2% glutaraldehyde was added to the PVA solution. Next, the 20 ml of PVA/GA solution was shifted to small beakers to prepare PVA/GA/ε-PL solution in different ratios such as 1ml ε-PL (PVA/GA/ε-PL-1), 0.75 ml ε-PL (PVA/GA/ε-PL-2), 0. 5ml ε-PL (PVA/GA/ε-PL-3), 0. 25ml ε-PL (PVA/GA/ε-PL-4). Pure PVA was used as a control. The solution of PVA/GA/ε-PL was coated on the UC by plasma-induced surface treatment to ensure optimal coating adhesion. The chemical analysis of the polymer-modified UC was performed by Fourier-Transform Infrared Spectroscopy (FTIR). The antimicrobial activity of modified UC was tested by a disc diffusion method and a colony forming unit/ml method against S. aureus. Results: The disc diffusion method confirmed the antimicrobial activity of polymer-coated UCs through a zones on the plates. The colony-forming unit/ml showed that polymer-coated UCs caused a 4-log reduction compared to the control. The four tested polymer-coated UCs restricted bacterial growth until three dilutions. Confocal microscopy was performed for further confirmation of the antimicrobial properties of the polymer-modified UCs. Sample 1 caused the death of 74% of cells, followed by sample 4 (69%), sample 2 (49%), and sample 3 (43%), whereas in control samples, only 29% of dead bacterial cells were found. Conclusion: Polymer-coated UCs showed promising antimicrobial effects against S. aureus.

Keywords: PVA; PLL; catheter; antimicrobial coatings,;Staphylococcus aureus.