In vitro evaluation of antiseptics against Staphylococcus aureus biofilms formed in different surroundings

Abstract

Background and aim. Bacterial biofilms have been studied widely and found to account for most of antibioticresistant and recurrent infections. Prosthetic vascular graft infection is one of the conditions when biofilms form on an implant and cause persistent infection that 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 that 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 the majority of prosthetic vascular graft infections in early postoperative period. Materials and methods. Three series of experiments were performed to test the efficacy of 0.1% octenidine dihydrochloride, 10% povidone-iodine, and 0.02% 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 structure and antimicrobial activity of the biofilm 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 compared to povidone-i.[...].