Gebel Jürgen, Rausch Marvin, Bienentreu Katja, Droop Felix, Eggers Maren, Gebel Lea, Gemein Stefanie, Hornei Britt, Ilschner Carola, Jacobshagen Anja, Kampf Günter, Papan Cihan, Roesch Kira, Schmitz Luisa, Suchomel Miranda, Vossebein Lutz, Mutters Nico T, Exner Martin
Institute for Hygiene and Public Health, University Clinics Bonn, Bonn, Germany.
VAH - Association for Applied Hygiene c/o Institute for Hygiene and Public Health, Bonn, Germany.
GMS Hyg Infect Control. 2024 Jan 30;19:Doc03. doi: 10.3205/dgkh000458. eCollection 2024.
To evaluate a newly developed microscale quantitative suspension test compared to the existing standard suspension test using determination of the bactericidal and yeasticidal activity of glutaral as one step to improve the sustainability of disinfectant testing.
The testing principles of the quantitative suspension test according to VAH method 9 (comparable to EN 13727) was used as a standard suspension test using 8.0 mL product test solution, 1.0 mL organic load and 1.0 mL test suspension. In addition, a micro-scale suspension test was performed in 96-well plates with 160 µL product test solution, 20 µL organic load and 20 µL test suspension. ATCC 6538, ATCC 15442 and ATCC 10231 were test organisms. Glutaral was tested at concentrations of 0.05%, 0.1%, 0.2% and 0.3% with exposure times of 1, 5 and 15 min. Polysorbate 80 (30 g/L), lecithin (9 g/L), L-histidine (1 g/L) and glycine (10 g/L) were used as validated neutralizers. After serial dilution of the disinfectant-neutralizer-mixture, plates were incubated for 48 h at 36°C (bacteria) or 72 hours at 30°C () and colony forming units (cfu) counted. The lg reduction was calculated as the difference between the results of the water control and the disinfectant at the end of the exposure time. All experiments were done in triplicate under clean conditions. Means of lg reduction were compared with the unpaired t-test, p<0.05 was considered to be significant.
Sufficient bactericidal activity according the VAH test requirements of at least 5 lg was found with both methods in 16 data sets of 24 data sets in total, and insufficient bactericidal activity of less than 5 lg was found with both methods in 7 data sets. In one data set, the mean lg reduction was above 5 lg with the microscale method and <5 lg with the VAH method, with no significant difference between the data sets (p=0.3096; 0.2% glutaral, 1 min, ). A sufficient yeasticidal activity of at least 4 lg was found with both methods in one data set, an insufficient yeasticidal activity of less than 4 lg was found with both methods in 8 data sets. With one exception, no significant differences were detected between the two methods below the efficacy threshold.
The microscale quantitative suspension test proved to provide results similar to those of VAH method 9 when the bactericidal and yeasticidal activity of glutaralwas evaluated, with 32 out of 33 evaluations yielding consistent results in terms of efficacy. Its suitability should be confirmed with additional bacterial species, additional biocidal active substances and in other laboratories.
通过测定戊二醛的杀菌和杀酵母活性，评估一种新开发的微量定量悬液试验，并与现有的标准悬液试验进行比较，以此作为提高消毒剂测试可持续性的一个步骤。
按照VAH方法9（等同于EN 13727）的定量悬液试验的测试原理，使用8.0 mL产品测试溶液、1.0 mL有机负荷和1.0 mL测试悬液进行标准悬液试验。此外，在96孔板中进行微量悬液试验，使用160 μL产品测试溶液、20 μL有机负荷和20 μL测试悬液。ATCC 6538、ATCC 15442和ATCC 10231作为测试微生物。戊二醛在浓度为0.05%、0.1%、0.2%和0.3%时进行测试，暴露时间为1、5和15分钟。聚山梨酯80（30 g/L）、卵磷脂（9 g/L）、L-组氨酸（1 g/L）和甘氨酸（10 g/L）用作经过验证的中和剂。消毒剂-中和剂混合物经系列稀释后，平板在36°C下孵育48小时（细菌）或在30°C下孵育72小时（酵母），并计算菌落形成单位（cfu）。lg减少量计算为暴露时间结束时水对照和消毒剂结果之间的差值。所有实验均在清洁条件下重复进行三次。lg减少量的平均值采用非配对t检验进行比较，p<0.05被认为具有显著性。
在总共24个数据集中的16个数据集中，两种方法均发现根据VAH试验要求具有至少5 lg的足够杀菌活性，在7个数据集中两种方法均发现杀菌活性不足，小于5 lg。在一个数据集中，微量方法的平均lg减少量高于5 lg，而VAH方法的平均lg减少量<5 lg，数据集之间无显著差异（p=0.3096；0.2%戊二醛，1分钟，酵母）。在一个数据集中，两种方法均发现具有至少4 lg的足够杀酵母活性，在8个数据集中两种方法均发现杀酵母活性不足，小于4 lg。除一个例外，在效力阈值以下两种方法之间未检测到显著差异。
在评估戊二醛的杀菌和杀酵母活性时，微量定量悬液试验证明提供的结果与VAH方法9相似，在33次评估中有32次在效力方面产生一致的结果。其适用性应通过其他细菌种类、其他生物杀灭活性物质以及在其他实验室进行确认。
