Efficacy of octenidine- and chlorhexidine-based wash-mitts against Candida albicans and Candida auris – a comparative study

Abstract

Management of outbreaks of the newly emerging pathogen Candida auris may include use of antimicrobial wash-mitts for decolonization. However, currently there is little clinical evidence to support the wide adoption of 'whole-body decolonization' as part of the protocol to effectively manage C.auris outbreaks. The aim of this study was to investigate the chemical tolerance of C.auris compared with the surrogate test organism Candida albicans as established in the European Standards (EN). Two commercially available antiseptic-impregnated wash-mitts based on either chlorhexidine digluconate (CHG) or octenidine dihydrochloride (OCT) were studied. Comparison of susceptibility of C.auris and C.albicans was investigated based on the standardized test protocol EN 13624. Experiments were conducted using the impregnation liquid squeezed from the wash-mitts at a contact time of 30s at different concentrations between 0.5% and 97% in the presence of low organic soiling. Yeasticidal efficacy according to EN 13624 was found for the OCT wash-mitts at 30s at ≥10% concentration with C.albicans. In comparison, reduction ≥4 log10 was found at a much lower concentration of ≥1% for both C.auris strains. For the CHG wash-mitts, efficacy against C.albicans was below 2 log10 reduction at 97% concentration within 30s. Efficacy against the two C.auris strains was around 3 log10 reduction. Both C.auris strains were found to be significantly more susceptible when compared with C.albicans. Data also demonstrate that not all antiseptic-impregnated wash-mitts are equally effective against C.auris with OCT having a higher efficacy compared with CHG.