In Vitro Evaluation of Several Antiseptic Solutions Against Staphylococcus Aureus Biofilms: Antiseptics are Able to Fight Staphylococcus Aureus Biofilms on Vascular Grafts

Abstract

Introduction - Bacterial biofilms have been studied widely and found to account for most antibiotic-resistant and recurrent infections. Prosthetic vascular graft infection is one of the conditions when biofilms form on an implant and cause persistent infection which is extremely difficult to eradicate without removing the graft itself. Currently many conservative treatment options are being explored to preserve the graft. One of these options is local wound irrigation with antiseptic solutions which so far has not been investigated widely enough. Our aim was to test the efficacy of several popular antiseptic solutions against Staphylococcus aureus biofilms in vitro as these bacteria are responsible for most prosthetic vascular graft infections in early postoperative period. Methods - Three series of experiments were performed to test the efficacy of octenidine dihydrochloride, povidone-iodine and chlorhexidine digluconate solutions against Staphylococcus aureus biofilms. Biofilms were grown on glass coverslips, in well-plates with Lubbock’s medium, mimicking the surroundings of the wound and on woven vascular grafts. Biofilms were then treated with antiseptics and their efficacy towards the biofilm’s structure and antimicrobial activity was evaluated. Results - Chlorhexidine digluconate showed outstanding results in destroying the structure of Staphylococcus aureus biofilm, grown on a glass coverslip (p=0.02). In simulated wound conditions, octenidine dihydrochloride and povidone-iodine eradicated biofilm-associated bacteria, while the efficacy of chlorhexidine digluconate was poor. All antiseptics showed positive antimicrobial effects against Staphylococcus aureus biofilms, grown on woven vascular grafts in simulated wound conditions (p=0.02). Additionally, octenidine dihydrochloride showed statistically significant superior effects comparing to povidone-iodine (p=0.009) and chlorhexidine digluconate solution (p=0.041). Conclusion - Chlorhexidine digluconate was most effective on glass coverslips. Both octenidine dihydrochloride and povidone-iodine eradicated biofilm-associated bacteria in simulated wound conditions. Octenidine dihydrochloride showed the strongest antimicrobial activity against Staphylococcus aureus biofilms formed on vascular grafts.