In 2022, the standard EN 17658 for laundry disinfection was released which uses Candida albicans as a test organism for yeasts.

Recently, a rise in infections by different Candida species, such as C. auris and C. parapsilosis, have been reported [1–3], which could result in a higher relevance of these species for laundry hygiene, not only in the hospital, but also in domestic health-care settings.

This study focuses on the reduction of four different Candida strains in standardized laundry processes according to EN 17658 to detect possible differences between the original test strain and emerging pathogenic Candida species.

A commercially available powder colour detergent, colour detergent combined with addition of a bleach releasing additive and a heavy-duty detergent were compared to the IEC A standard detergent with and without added activated oxygen bleach. Test were performed at 40 °C, which on the one hand is the highest allowed temperature for the test method but on the other hand ensures sufficient bleach activation. The experimental setup allows for an assessment of the hygiene efficacy based on domestic washing procedures, which are important for people being cared for at home but could also be used to estimate the efficacy of professional hospital laundering.

Our results show a differential behavior of the investigated strains, thus suggesting a need for monitoring the hygienic efficacy of laundry processes on emerging Candida species.

References:

Branco, J., Miranda, I. M. & Rodrigues, A. G. Candida parapsilosis Virulence and Antifungal Resistance Mechanisms: A Comprehensive Review of Key Determinants. J. Fungi 9, 80 (2023).Sun, M. et al. Increase in Candida parapsilosis candidemia in cancer patients. Mediterr. J. Hematol. Infect. Dis. 11, 1–7 (2019).Cristina, M. L. et al. An Overview on Candida auris in Healthcare Settings. J. Fungi 9, 913 (2023).