The Effect of Copper-iodine Complex Solution on the Killing and Antimicrobial Persistence of Two Candida Species (C. Albicans and C. Auris): An in vitro Model

Introduction: Yeast infections, such as that produced by Candida spp., are common in chronic wounds and burns. C. albicans-related infection has multiple treatment options, both topical and pharmaco- logical. However, C. auris is an emerging World Health Organization threat with no known pharmacologic treatment course and can lead to morbidity and mortality. The purpose of this in vitro study is to demonstrate the killing effect and antimicrobial persistence of copper iodine irrigation solution (CICS) on two yeast species. Methods: Each test article (CICS or 1 ppm Lugol’s iodine) was inoc- ulated with ~105 CFU/mL of C. albicans or C. auris. After a 10-minute exposure time (sample 0 mins), samples were neutralized, diluted, and plated. To assess the antimicrobial per- sistence, the same samples were rechallenged by renoculating~105 CFU/mL of each organism at 10 mins, 2 hours, 5 hours, and 24 hours and neutralized after a 10-minute exposure time. Results: High antimicrobial efficacy ( >99.999% or 5 log reduction) of CICS was demonstrated when rechallenged by reinoculations over 24 hours for both C. albicans and C. auris. Lugol’s iodine showed loss of activity in 2 hours of exposure. Discussion: Copper-Iodine Complex Solution demonstrated an effective kill rate and antifungal persistence in vitro with both C. albicans and C. auris. This has significant implications for acute and chronic wounds, trauma and burns, especially when there is no pres- ent medicinal treatment for C. auris. Further studies are warranted to support these findings.