Efficacy of Biofilm Disrupters Against Candida auris and Other Candida species

Abstract

ABSTRACTBackgroundC. auris has become a globally emerging fungal pathogen, frequently reported to be multi-drug resistant, commonly found with Staphylococcus aureus in polymicrobial nosocomial infections. Although chlorhexidine (CHD) has been shown to be effective, it is associated with serious anaphylaxis reactions. Biofilm disrupters (BDs) are novel agents with a broad spectrum of antimicrobial activity. BDs have been used in the management of chronic wounds and to sterilize environmental surfaces. The goal of this study was to evaluate BDs against polymicrobial biofilms compared to CHD.MethodologyWe evaluated various BDs (BlastX, Torrent, NSSD) and CHD against Candida spp and S. aureus polymicrobial biofilms by zone of inhibition, biofilm, and time-kill assays. Effectiveness was based on the inhibition zone and the reduction of CFU, respectively, compared to the drug-free control.ResultsAll BDs and CHD inhibited C. auris growth effectively in a concentration-dependent manner. Additionally, CHD and the BDs all showed excellent antimicrobial activity against polymicrobial biofilms. BDs were all highly effective against both C. auris isolates, whereas CHD was only moderately effective against C. auris 0386, suggesting resistance/tolerance. A comparative analysis of the BDs and CHD against C. auris and C. albicans by biofilm kill-curves showed at least 99.999% killing.ConclusionsAll three BDs and CHD have excellent activity against different Candida species, including C. auris. However, certain isolates of C. auris showed resistance/tolerance to CHD, but not to the BDs. The fungicidal activity of these novel agents will be valuable in eradicating surface colonization of Candida spp, including C. auris.