Efficacy of 233 nm LED far UV-C-radiation against clinically relevant bacterial strains in the phase 2/ step 2 in vitro test on basis of EN 14561 and on an epidermis cell model

Claudia Sicher; Nevin Opitz; Pia Elen Becker; Neysha Lobo Ploch; Johannes Schleusener; Michael Kneissl; Axel Kramer; Paula Zwicker

doi:10.1016/j.micinf.2024.105320

Efficacy of 233 nm LED far UV-C-radiation against clinically relevant bacterial strains in the phase 2/ step 2 in vitro test on basis of EN 14561 and on an epidermis cell model

Microbes Infect. 2024 Mar 9:105320. doi: 10.1016/j.micinf.2024.105320. Online ahead of print.

Authors

Claudia Sicher¹, Nevin Opitz¹, Pia Elen Becker¹, Neysha Lobo Ploch², Johannes Schleusener³, Michael Kneissl⁴, Axel Kramer¹, Paula Zwicker⁵

Affiliations

¹ Institute of Hygiene and Environmental Medicine, Ferdinand-Sauerbruch-Str., University Medicine Greifswald, 17475 Greifswald, Germany.
² Ferdinand-Braun-Institut gGmbH, Leibniz-Institut Für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin, Germany.
³ Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117, Berlin, Germany.
⁴ Ferdinand-Braun-Institut gGmbH, Leibniz-Institut Für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin, Germany; Institute of Solid State Physics, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany.
⁵ Institute of Hygiene and Environmental Medicine, Ferdinand-Sauerbruch-Str., University Medicine Greifswald, 17475 Greifswald, Germany. Electronic address: paula.zwicker@med.uni-greifswald.de.

PMID: 38461969
DOI: 10.1016/j.micinf.2024.105320

Abstract

Introduction: Healthcare-acquired infections and overuse of antibiotics are a common problem. Rising emergence of antibiotic and antiseptic resistances requires new methods of microbial decontamination or decolonization as the use of far-UV-C radiation.

Methods: The microbicidal efficacy of UV-C radiation (222 nm, 233 nm, 254 nm) was determined in a quantitative carrier test and on 3D-epidermis models against Staphylococcus (S.) aureus, S.epidermidis, S.haemolyticus, S.lugdunensis, Klebsiella pneumoniae, and Pseudomonas aeruginosa. To mimic realistic conditions, sodium chloride solution, mucin, albumin, artificial saliva, artificial wound exudate and artificial sweat were used.

Results: In sodium chloride solution, irradiation with a dose of 40 mJ/cm² (233 nm) was sufficient to achieve 5 lg reduction independent of bacteria genus or species. In artificial sweat, albumin and artificial wound exudate, a reduction >3 lg was reached for most of the bacteria. Mucin and artificial saliva decreased the reduction to <2 lg. On 3D epidermis models, reduction was lower than in the carrier test.

Conclusion: UV-C radiation at 233 nm was proven to be efficient in bacteria inactivation independent of genus or species thus being a promising candidate for clinical use in the presence of humans and on skin/mucosa.

Keywords: Antibacterial; Carrier test; Irradiation; MRSA; UV; UV-C radiation.