S Gemein1, J Gebel2, B Christiansen3, H Martiny4, L Vossebein5, F H H Brill6, M Decius7, M Eggers8, T Koburger-Janssen9, M Meckel10, S Werner11, B Hunsinger12, T Selhorst13, G Kampf14, M Exner15. 1. Institute for Hygiene and Public Health, University Hospital Bonn, Bonn, Germany; VAH Ring Trial Steering Gremium of the Association for Applied Hygiene (VAH), Bonn, Germany. Electronic address: stefanie.gemein@ukbonn.de. 2. Institute for Hygiene and Public Health, University Hospital Bonn, Bonn, Germany; VAH Ring Trial Steering Gremium of the Association for Applied Hygiene (VAH), Bonn, Germany; Disinfectant Commission 4+4-Group of the Association for Applied Hygiene (VAH), Bonn, Germany. 3. Disinfectant Commission 4+4-Group of the Association for Applied Hygiene (VAH), Bonn, Germany; ZE Medizinaluntersuchungsamt und Hygiene, University Hospital Schleswig Holstein, Kiel, Germany. 4. VAH Ring Trial Steering Gremium of the Association for Applied Hygiene (VAH), Bonn, Germany; Disinfectant Commission 4+4-Group of the Association for Applied Hygiene (VAH), Bonn, Germany. 5. Disinfectant Commission 4+4-Group of the Association for Applied Hygiene (VAH), Bonn, Germany; University of Applied Sciences Niederrhein, Mönchengladbach, Germany. 6. Dr Brill + Partner GmbH, Institut für Hygiene und Mikrobiologie, Hamburg, Germany. 7. ZE Medizinaluntersuchungsamt und Hygiene, University Hospital Schleswig Holstein, Kiel, Germany. 8. Labor Prof. Gisela Enders MVZ GbR, Stuttgart, Germany. 9. Hygiene Nord GmbH, Greifswald, Germany. 10. IKI Institut für Krankenhaushygiene und Infektionskontrolle GmbH, Gießen, Germany. 11. HygCen Germany GmbH, Schwerin, Germany. 12. VAH Ring Trial Steering Gremium of the Association for Applied Hygiene (VAH), Bonn, Germany. 13. Institut für Tierwissenschaften, Präventives Gesundheitsmanagement, University Bonn, Germany. 14. Institute for Hygiene and Environmental Medicine, University Medicine Greifswald, Greifswald, Germany. 15. Institute for Hygiene and Public Health, University Hospital Bonn, Bonn, Germany.
Abstract
BACKGROUND: Sporicidal surface disinfection is recommended to control transmission of Clostridium difficile in healthcare facilities. EN 17126 provides a method to determine the sporicidal activity in suspension and has been approved as a European standard. In addition, a sporicidal surface test has been proposed. AIM: To determine the interlaboratory reproducibility of a test method for evaluating the susceptibility of a C. difficile spore preparation to a biocidal formulation following the 4-field test (EN 16615 methodology). METHODS: Nine laboratories participated. C. difficile NCTC 13366 spores were used. Glutaraldehyde (1% and 6%; 15 min) and peracetic acid (PAA; 0.01% and 0.04%; 15 min) were used to determine the spores' susceptibility in suspension in triplicate. FINDINGS: One-percent glutaraldehyde revealed a mean decimal log10 reduction of 1.03 with variable results in the nine laboratories (0.37-1.49) and a reproducibility of 0.38. The effect of 6% glutaraldehyde was stronger (mean: 2.05; range: 0.96-4.29; reproducibility: 0.86). PAA revealed similar results. An exemplary biocidal formulation based on 5% PAA was used at 0.5% (non-effective concentration) and 4% (effective concentration) to determine the sporicidal efficacy (4-field test) under clean conditions in triplicate with a contact time of 15 min. When used at 0.5% it demonstrated an overall log10 reduction of 2.68 (range: 2.35-3.57) and at 4% of 4.61 (range: 3.82-5.71). The residual contamination on the three primarily uncontaminated test fields was <50 cfu/25 cm2 in one out of nine laboratories (0.5%) and in seven out of nine laboratories (4%). CONCLUSION: The interlaboratory reproducibility seems to be robust.
BACKGROUND: Sporicidal surface disinfection is recommended to control transmission of Clostridium difficile in healthcare facilities. EN 17126 provides a method to determine the sporicidal activity in suspension and has been approved as a European standard. In addition, a sporicidal surface test has been proposed. AIM: To determine the interlaboratory reproducibility of a test method for evaluating the susceptibility of a C. difficile spore preparation to a biocidal formulation following the 4-field test (EN 16615 methodology). METHODS: Nine laboratories participated. C. difficile NCTC 13366 spores were used. Glutaraldehyde (1% and 6%; 15 min) and peracetic acid (PAA; 0.01% and 0.04%; 15 min) were used to determine the spores' susceptibility in suspension in triplicate. FINDINGS: One-percent glutaraldehyde revealed a mean decimal log10 reduction of 1.03 with variable results in the nine laboratories (0.37-1.49) and a reproducibility of 0.38. The effect of 6% glutaraldehyde was stronger (mean: 2.05; range: 0.96-4.29; reproducibility: 0.86). PAA revealed similar results. An exemplary biocidal formulation based on 5% PAA was used at 0.5% (non-effective concentration) and 4% (effective concentration) to determine the sporicidal efficacy (4-field test) under clean conditions in triplicate with a contact time of 15 min. When used at 0.5% it demonstrated an overall log10 reduction of 2.68 (range: 2.35-3.57) and at 4% of 4.61 (range: 3.82-5.71). The residual contamination on the three primarily uncontaminated test fields was <50 cfu/25 cm2 in one out of nine laboratories (0.5%) and in seven out of nine laboratories (4%). CONCLUSION: The interlaboratory reproducibility seems to be robust.
Authors: Patryk Tarka; Agnieszka Chojecka; Olga Paduch; Aneta Nitsch-Osuch; Krzysztof Kanecki; Anna Kierzkowska Journal: Int J Environ Res Public Health Date: 2019-09-18 Impact factor: 3.390
Authors: Weronika Augustyn; Arkadiusz Chruściel; Wiesław Hreczuch; Joanna Kalka; Patryk Tarka; Wojciech Kierat Journal: Int J Environ Res Public Health Date: 2022-01-10 Impact factor: 3.390