EC Microbiology

Background: Candida auris is an emerging fungus currently considered a serious global health threat. CDC has deemed Candida auris an “urgent antimicrobial resistant threat as it is often resistant to multiple antifungal drugs, spreads easily in healthcare facilities, and can cause severe infections with high death rates”. Candida auris is difficult to identify with standard laboratory methods, exacerbating persistent outbreaks attributed to surface contamination [1].

This study examines the efficacy of modulated dielectric barrier discharge atmospheric nonthermal plasma air treatment against Candida auris in air and on surfaces.

Methods: Log reductions were recorded over time with modulated dielectric barrier discharge atmospheric nonthermal plasma air treatment of aerosolized Candida auris. Candida auris inoculated stainless steel, floor-tile, and plastic coupons were measured in a test room 22’ x 12’ x 10’.

Results: At 2 (two) minutes of treatment in all samples, no Candida auris was detected (at limits of detection). Log reductions up to 4.52 were observed at 30-seconds of treatment.

Discussion: “No-touch”, automated enhancements such as modulated dielectric barrier discharge nonthermal plasma air treatment can reduce reliance on human operators and so have the potential to improve disinfection outcomes and the success of terminal disinfection [2] when used with current protocols in healthcare environments. Disinfection with modulated dielectric barrier discharge-generated nonthermal plasma demonstrated reductions to non-detectable levels in 2 minutes of aerosolized Candida auris and inoculations on common surfaces.

Conclusion: The efficacy of modulated dielectric barrier discharge nonthermal plasma air treatment to destroy Candida auris shown in this study suggests it is a highly effective enhancement to Candida auris mitigation in healthcare environments.

Keywords: Dielectric Barrier Discharge; Nonthermal Plasma; Cold Plasma; Candida auris; Infection Prevention; No-Touch Disinfection

1. Centers for Disease Control and Prevention. Increasing Threat of Spread of Antimicrobial-resistant Fungus in Healthcare Facilities (2020).
2. Otter JA., et al. “A guide to no-touch automated room disinfection (NTD) systems”. Decontamination in Hospitals and Healthcare (2014): 413-460.
3. Khojasteh S., et al. “Candida auris and COVID-19: A health threatening combination”. Current Medical Mycology3 (2022): 44-50.
4. Centers for Disease Control and Prevention. About Candida Auris (C. auris) (2023).
5. Haq M., et al. “Efficacy of 23 commonly used liquid disinfectants against Candida auris isolates from the 4 major clades”. Infection Control and Hospital Epidemiology (2023): 1-5.
6. Daniel Y Fung. “Rapid Methods and Automation in Microbiology 25 years of Developments and Predictions”. Ph.D., Professor of Food Science, Kansas State University, Manhattan, Kansas University Distinguished Professor, UAB, Barcelona Spain (2007).