The Antifungal Activity of a Polygalacturonic and Caprylic Acid Ointment in an In Vitro, Three-Dimensional Wound Biofilm Model

<i>Candida</i> colonization and biofilms are significant contributors to impaired wound healing. Consequently, improved treatments are needed to eradicate <i>Candida</i> biofilms in wounds. Wounds present complex biofilm extracellular matrix environments, with microbial cells frequently enmeshed in matrices comprising wound exudate macromolecular gels. We evaluated the ability of a polygalacturonic and caprylic acid (PG + CAP) ointment to eradicate <i>Candida albicans</i>, <i>C. parapsilosis</i>, <i>C. glabrata</i>, <i>C. tropicalis</i>, and <i>C. auris</i> biofilms in a fibrin gel wound biofilm model of the complex wound biofilm environment. Hypochlorous acid (HOCl) is a disinfecting antimicrobial agent that is widely used as wound irrigant, and this was used as a comparator. A single treatment with PG + CAP reduced the number of viable organisms in the <i>C. albicans</i> and <i>C. glabrata</i> biofilms by over 5 log₁₀, in the <i>C. parapsilosis</i> and <i>C. auris</i> biofilms by over 4 log₁₀, and in the <i>C. tropicalis</i> biofilm by 3.85 log₁₀. PG + CAP was superior (<i>p</i> < 0.01) to HOCl in eradicating all <i>Candida</i> species biofilms, except for <i>C. auris</i>, for which both treatments fully eradicated all viable organisms. The use of HOCl in <i>Candida</i>-colonized wounds should include consideration of the extracellular matrix load in the wound bed. PG + CAP warrants further study in wounds compromised by <i>Candida</i> biofilms.