Povidone iodine demonstrates strong efficacy in reducing Candida biofilm in an in vitro fungal prosthetic infection

Periprosthetic joint infection (PJI) caused by fungi is rare but can lead to devastating outcomes. However, the best treatment for fungal PJI has not been established. This study aims to identify the optimal surgical irrigation solution to reduce the bioburden of Candida biofilm from prosthetic surfaces. Candida albicans biofilm was cultured on titanium screw caps and treated for 3 min and 10 min using five clinically used irrigation solutions: Normal Saline, Fluconazole solution (2000 µg/mL), Nystatin solution (5000 IU/mL), Chlorhexidine (0.05%), Povidone Iodine (0.35%), and Povidone Iodine (10%). The biofilm on the screw caps was quantified by counting colony-forming units after sonication to assess the effectiveness of the irrigation solutions. Irrigation with normal saline resulted in 5.9 ± 1.6 × 104 CFU/mL of Candida albicans per titanium screw cap. As compared to the normal saline, the most effective irrigation solution at 3 min was PI 10%, achieving over a 2-log reduction in CFU/ml. Other chemical irrigation solutions resulted in approximately a 1-log reduction. Extending the irrigation time to 10 min led to a further reduction in biofilm, with PI 0.35% and PI 10% achieving remarked removal. These findings suggest that PI 10% is the most effective irrigation solution for treating Candida-induced PJI when applied for 3 min. However, its efficacy is time dependent, and prolonged irrigation can achieve clinical significance even at lower concentrations.