Palma Francesco, Díaz-Navarro Marta, Visedo Andrés, Sanz-Ruíz Pablo, Brandi Giorgio, Schiavano Giuditta Fiorella, Guembe María
Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy.
Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain.
Front Microbiol. 2025 Jul 22;16:1570334. doi: 10.3389/fmicb.2025.1570334. eCollection 2025.
Biofilm-related Multidrug Resistance (MDR) is a major problem in healthcare-associated infections (HAI). Hospital surface decontamination is essential to ensure the safety of patients and to eliminate the dissemination of MDR pathogens. New eco-friendly decontamination technologies, such as UV-C irradiation, are only gaining popularity now, but their use against the biofilm of common microorganisms causing HAI has not been properly assessed. We aimed to assess the efficacy of UV-C irradiation (254 nm) in a 2-phase study by assessing its anti-biofilm effect against sessile cells from microorganisms of hospital interest.
The following strains were tested: methicillin-susceptible (MSSA) (ATCC 29213), methicillin-resistant (MRSA) (ATCC 43300), ATCC 25922, ATCC 15442, and (ATCC 14053), and a clinical strain of methicillin-resistant . First, the tested strains' UV-susceptibility was evaluated through irradiation tests on plates using different UV doses, considering both planktonic and 24 h-biofilm states. Second, the anti-biofilm effect of UV-C was evaluated on stainless steel discs contaminated with a 24 h-biofilm of each strain.
With a UV dose of 946.7 mJ/cm, the UV-C irradiation on MSSA ATCC 29213, MRSA ATCC 43300, and MRSE biofilm showed a log reduction of 4.34 ± 0.70, 4.70 ± 0.60, and 4.85 ± 0.98, respectively, while ATCC 14053 showed higher UV-resistance in 24 h-biofilm state, being the log reduction of 3.17 ± 0.08. Against Gram negative bacteria biofilm, a UV dose of 467.8 mJ/cm was enough to achieve a microbial titer <1 CFU/mL. Regarding the 24 h-biofilm on discs, a log reduction >3 logs was achieved with all microorganisms applying a UV dose of 946.7 mJ/cm.
The application of UV-C irradiation could be a valid additional approach in the management of biofilm HAI.
生物膜相关的多重耐药性（MDR）是医疗相关感染（HAI）中的一个主要问题。医院表面消毒对于确保患者安全和消除多重耐药病原体的传播至关重要。新型环保消毒技术，如紫外线C（UV-C）辐照，目前才开始受到关注，但其对引起HAI的常见微生物生物膜的作用尚未得到充分评估。我们旨在通过评估UV-C辐照（254nm）对医院相关微生物固着细胞的抗生物膜作用，在一项两阶段研究中评估其效果。
测试了以下菌株：甲氧西林敏感金黄色葡萄球菌（MSSA）（ATCC 29213）、耐甲氧西林金黄色葡萄球菌（MRSA）（ATCC 43300）、ATCC 25922、ATCC 15442和（ATCC 14053），以及一株耐甲氧西林临床菌株。首先，通过使用不同紫外线剂量在平板上进行辐照试验，评估受试菌株对紫外线的敏感性，同时考虑浮游状态和24小时生物膜状态。其次，在被各菌株24小时生物膜污染的不锈钢圆盘上评估UV-C的抗生物膜作用。
在紫外线剂量为946.7 mJ/cm²时，对MSSA ATCC 29213、MRSA ATCC 43300和耐甲氧西林表皮葡萄球菌（MRSE）生物膜的UV-C辐照分别使对数减少4.34±0.70、4.70±0.60和4.85±0.98，而ATCC 14053在24小时生物膜状态下表现出更高的抗紫外线能力，对数减少为3.17±0.08。对于革兰氏阴性菌生物膜，紫外线剂量为467.8 mJ/cm²足以使微生物滴度<1 CFU/mL。对于圆盘上的24小时生物膜，使用946.7 mJ/cm²的紫外线剂量对所有微生物均实现了对数减少>3个对数。
UV-C辐照的应用可能是管理生物膜HAI的一种有效辅助方法。
