UC San Diego

Candida albicans and Candida auris are fungal pathogens with the potential to cause severe invasive diseases in patients that are immunocompromised, such as cancer and organ transplant patients. Infections with these fungal pathogens are increasing due to a growing at-risk population, widespread use of antibiotics, and an increase in invasive medical procedures. In addition, antifungal resistance is increasing in these pathogens. Thus, it is a paramount concern to decolonize high risk patients to reduce the risk of subsequent systemic infection. Azole creams have been used to treat cutaneous candidiasis; however, increasing resistance to this drug class emphasizes the need for alternative topical treatments. Traditional povidone-iodine is effective against Candida, yet it is composed of only 0.01% iodine species, and can also cause staining of the skin and irritation. We therefore assessed a new formula of molecular pure non-staining iodine (I2) that uses simple glycerol as a carrier to deliver a high concentration of I2. We define the potency of this new formula of I2 against Candida species by determining its minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC). MIC and MFC were uniform among the pathogens tested, measuring 3-6 parts per million (ppm) for C. albicans and 2-4 ppm for C. auris. In preliminary studies using a murine skin infection model, C. auris was susceptible to iodine treatment, but we were not able to find differences in C. albicans fungal burden.