Abstract
Objectives: Management of outbreaks of the newly emerging pathogen Candida auris may include use of antimicrobial wash-mitts for decolonization. In the absence of large-scale clinical trials, the immediate assessment of the efficacy claims for these products can be based on in vitro experimental data that follows the standard protocols established by CEN (European committee for Standardization). In this study, the chemical tolerance of C. auris was compared with the surrogate test organism Candida albicans as established in the European standards (EN). Methods: The study was conducted following the protocol for the quantitative suspension test EN 13624 using C. albicans ATCC 10231 in comparison to C. auris DSMZ 21092 and C. auris DSMZ 105986. Two commercially available wash-mitts containing chlorhexidine digluconate (CHG) or octenidine dihydrochloride (OCT) were used. Experiments were conducted using the impregnation liquid squeezed from the wash-mitts at different dilution concentrations between 0.5% to 97% at a contact time of 30 sec in the presence of 0.03% bovine serum. Results: Yeasticidal efficacy according to EN 13624 was found for the OCT wash-mitts at 30 sec at ≥ 10% concentration with C. albicans (≥ 4 log RF). In comparison, for both C. auris strains ≥ 4 log RF was found at a much lower concentration of ≥ 1%. For the CHG wash-mitts efficacy against C. albicans was below 2 log RF at 97% concentration within 30 sec. In contrast efficacy against the two C. auris strains was around 3 log RF. Conclusion: In conclusion, both C. auris strains were found to be significantly more susceptible when compared to C. albicans in this study. Moreover, our data also demonstrates that not all antiseptic-impregnated body wipes is equally effective against C. auris with OCT having a higher efficacy compared to CHG.