evaluation of two ozonation devices

Funding Information: We would like to thank Dr. Fernando Ferrari for carrying out the statistical analyses. This study was financed in part by the Coordena\u00E7\u00E3o de Aperfei\u00E7oamento de Pessoal de N\u00EDvel Superior \u2013 Brazil (CAPES) \u2013 Finance Code 001, Universidade Federal de Mato Grosso do Sul-UFMS/MEC, Brazil, and National Council for Scientific and Technological Development \u2013 CNPq Brazil. Publisher Copyright: Copyright © 2024 Caetano et al.Introduction: Candida albicans and Aspergillus fumigatus are two important agents of Healthcare-associated infections. This study aimed to evaluate the antifungal activity of ozone (O3) gas produced by two commercial devices against cultures of these two species. Methodology: Sterile plastic plates were inoculated with C. albicans and A. fumigatus and placed on a countertop at three distances (30 cm, 1 m, and 2 m) and three positions in relation to the wall (near, middle, and away), considering the source of O3. Plates were exposed to O3 for one hour and incubated. After incubation, the counting of colony-forming units was performed. As a control, an inoculated plate was incubated, without being exposed to O3. Tests were carried out with two different devices (namely, Mod.I and Mod.II), with the air conditioner on and off, in triplicate. Results: Both devices showed antifungal activity. Mod. I presented better results, due to a higher flow rate. The best activity was on plates at 30 cm, middle position. Contrarily, on plates at 2m, near the wall, the inhibition activity was lower. The best results were obtained with the air conditioner off. Candida albicans was more sensitive to O3 than A. fumigatus. Conclusions: This method of decontamination by O3 gas shows potential due to its fast and easy execution. The establishment of new protocols for hygiene and hospital disinfection using this approach should be considered, which may reduce environmental contamination by fungi and, consequently, the burden of fungal infections.publishersversionpublishe

Antimicrobial action of ozone gas on surfaces and in the air

Funding Information: This study was carried out with support from the Federal University of Mato Grosso do Sul (UFMS/MEC–Brazil) and the Coordination for the Improvement of Higher Education Personnel (CAPES) – Financing Code 001. Publisher Copyright: © 2021 Departamento de Enfermagem/Universidade Federal de Sao Paulo. All rights reserved.Objetivo: Avaliar a ação antimicrobiano do gás ozônio (O3) em superfícies e ar ambiente climatizado artificialmente. Métodos: Estudo experimental/laboratorial e transversal realizado em dez salas de um laboratório de pesquisa em microbiologia médica, com risco de segurança biológica classe 2. As superfícies demarcadas do chão, parede e bancada foram avaliadas, quanto à presença ou ausência de micro-organismos, a partir de coletas feitas com swab umedecido em água destilada estéril, antes e após a exposição do gás O3 gerado por dois equipamentos distintos. Após este procedimento, o swab foi inoculado na superfície do meio de cultura Brain Heart Infusion Agar DIFCO® (BHI), seguindo-se a incubação a 35ºC por 24 horas. Para a análise microbiológica do ar, uma placa com BHI foi exposta aberta por uma hora, antes e após o tratamento do gás O3, sendo incubadas segundo os mesmos critérios. Resultados: A atividade antimicrobiana do gás O3 gerado por ambos os equipamentos foi constatada para todas as áreas investigadas, com registros de redução do número de Unidades Formadoras de Colônias. O potencial de inibição antimicrobiana dos aparelhos se manteve próximo para os critérios de análise adotados, com destaque para as áreas de chão e bancada. Considerando-se todas as salas e percentuais de inibição microbiana, frente aos dois equipamentos, os resultados foram: chão (100%), bancada (90%), parede (50%) e ar, 70%. Conclusão: Os equipamentos geradores de gás O3 apresentaram potencial antimicrobiano para medida de controle de microrganismos presentes em superfícies e ar ambiente climatizado artificialmente, sendo um sanitizante factível para utilização. Objective: Assess the antimicrobial action of ozone gas (O3) on surfaces and artificially cooled ambient air. Methods: Cross-sectional experimental/laboratory study carried out in ten rooms of a medical microbiology research lab, with class 2 biosafety risk. The demarcated surfaces on the floor, wall and counter were assessed in relation to the presence or absence of microorganisms, based on collections done with swabs dampened in sterile distilled water, before and after exposure to ozone gas produced by two different generators. After this procedure, each swab was inoculated on the surface of a Brain Heart Infusion Agar DIFCO® (BHI) culture, followed by incubation at 35ºC for 24 hours. For the microbiological analysis of the air, a petri dish with BHI was openly exposed for one hour, before and after treatment with O3 gas, and were incubated according to the same criteria. Results: The antimicrobial activity of the O3 gas produced by both generators was checked in all the areas investigated, with records indicating a decrease in the number of colony-forming units. The antimicrobial inhibition potential of the generators was close to the analysis criteria adopted, particularly for the floor and counter areas. Based on all the rooms and microbial inhibition percentages, in relation to the two generators, the results were: floor (100%), counter (90%), wall (50%) and air (70%). Conclusion: The O3 generators had antimicrobial potential as a procedure for controlling microorganisms present on surfaces and in artificially cooled ambient air, constituting a feasible sanitizer.publishersversionpublishe