Antiseptics' Concentration, Combination, and Exposure Time on Bacterial and Fungal Biofilm Eradication

Area of Science:

• Microbiology
• Infectious Diseases
• Biomedical Engineering

Background:

• Periprosthetic joint infection (PJI) is a severe complication of joint replacement surgery.
• Microbial biofilms on implants pose a significant challenge in PJI treatment.
• Antiseptic solutions are crucial for managing PJI, necessitating efficacy studies.

Purpose of the Study:

• To evaluate the anti-biofilm activity of povidone-iodine (PI) and hydrogen peroxide (H₂O₂) solutions.
• To compare the efficacy of PI and H₂O₂ alone or in combination against microbial biofilms relevant to PJI.
• To determine optimal concentrations and exposure times for these antiseptics in PJI management.

Main Methods:

• Testing antiseptic solutions on 2-day-old and 5-day-old biofilms of Gram-positive bacteria, Gram-negative bacteria, and fungi.
• Quantifying biofilm metabolic activity using the XTT reduction assay.
• Assessing bacterial viability with colony-forming unit counts for aged biofilms.

Main Results:

• Both PI and H₂O₂ demonstrated concentration-dependent anti-biofilm activity, with exceptions like *E. faecalis*.
• 5% PI was most effective against 2-day-old biofilms across all tested microorganisms.
• 0.3% PI + 0.5% H₂O₂ showed significant efficacy at 3 minutes, particularly against Gram-positive bacteria in 5-day-old biofilms, outperforming 5% PI in metabolic activity reduction.

Conclusions:

• For PJI caused by Gram-positive bacteria, 3-minute wound irrigation with 0.3% PI + 0.5% H₂O₂ is recommended.
• For PJI with different or unknown etiologies, 5% PI for 1-minute exposure is advised.
• These findings provide guidance for antiseptic use in PJI treatment, optimizing efficacy based on causative agents and biofilm age.