Antifungal Properties of a Controlled-Release Iodine Foam Dressing and Two Gentian Violet/Methylene Blue Foam Dressings against Candida auris

Abstract Body: First reported in 2009, Candida auris (C. auris) has emerged as a multidrug-resistant, highly invasive, hospital-acquired fungal pathogen. With clinical isolates identified from five continents and a high incidence of severe infection and death, vigilant global efforts are underway to develop infection control and prevention strategies and to design effective treatment protocols. Candida spp. members are the most frequently isolated yeasts from polymicrobial chronic wounds. Therefore, the goal of this study was to determine the anti-fungal effectiveness of foam wound dressings containing either organic pigments (gentian violet/methylene blue)*,# or controlled-release iodophor$ against C. auris.                Following AATCC Test Method 100 (2012) and general laboratory practice with aseptic conditions guidelines, two dressings containing organic pigments, one containing controlled-released iodophor, and one control with no active ingredient& were tested. Samples were independently challenged with C. auris (CDC AR Bank #390) in simulated wound fluid. Time-point zero (T=0) samples were immediately neutralized and enumerated. The remaining samples were placed in a 35-39°C / ≥70% relative humidity chamber and either neutralized and enumerated at 30 minutes or re-inoculated at day 4 and then processed at 7 days.                Antifungal effectiveness was determined by comparing the microbial burden of dressings with active ingredients*,#,$ to that of negative control&. We observed a 4.70 ± 0.04 Log10 reduction at 30 minutes and a 5.60 ± 0.0 Log10 reduction at 7 days in the iodofor-containing dressing. Conversely, no reduction in microbial burden was observed in dressings containing organic pigments (methylene blue/gentian violet)*,# at 30 minutes and only one of the organic pigment-containing dressings* showed a minimal 0.36 ± 0.09 Log10 reduction at 7 days.                This study demonstrates that dressings containing a controlled-release iodophor were effective at eliminating more than 99.99% of C. auris by 30 minutes and for up to 7 days in an in vitro simulated would fluid environment.