Due to the fact that a relatively large area can be disinfected in a short time, dry-fog disinfection could have a great potential to improve hygienic measures. However, there are few studies to date on the effectiveness and combinability of this technology with other devices. In this work, the disinfecting potential of the TBT dry fogging technology (TBT Desinfektion GmbH & Co. KG, Germany) and the corresponding disinfectant Defeat AR (Biofluid GmbH, Germany) was examined with regard to microbiological decontamination and potential damaging effects on different devices. The airburden measurement did show a reduction of approx. 66% of the microbiological room contamination. Similarly, decontamination of test surfaces was shown to be effective at all measuring points we selected in the experimental setup. Depending on the accessibility of the surfaces this effect was in the range of several log levels. Nevertheless, a first test run showed that some technical equipment was negatively affected by the process.

Antimicrobial coatings are typically tested for their activity and effectiveness based on an artificial procedure, the standard JIS Z 2801 (or ISO 22196). The test samples are contaminated with a predetermined concentration of bacteria and covered with a sterile film. Due to the artificial structure of this process, however, there is always the question of the validity in the practical application of these surfaces and how comparable this germ-reducing effect is to currently common disinfection measures. Therefore, we developed a more realistic test procedure in our laboratory. The test samples are inoculated and incubated at standard room conditions. To compare the antimicrobial activity to standard cleaning procedures also disinfection and wipe controls were performed. The results show that the antimicrobial test patterns we use have a strong efficacy. This could be shown reproducibly both with the standard method JIS Z 2801 as well as with our new test procedure.

Cold plasma disinfection is a cost-efficient and, above all, fast way of disinfecting even complex products. There are already approaches where plasma disinfection is used for wound treatment or hand disinfection. The ionization of a gas results in a number of physical and chemical processes that have a damaging effect on microorganisms. Especially in the field of medical device reprocessing, a tool that can reliably disinfect even very complex products in a short time would be a great asset. In this work, the potential of a newly developed cold plasma disinfection device was tested for the reduction of microbiological contamination and thus the disinfecting effect. In order to examine this microbiological reduction 3D printed scaffolds with contaminated test plates were used. This was done with different concentrations of the bacteria in the cold plasma disinfection process to determine the maximum germ reduction effect. In a first test run, the maximum effect of germ reduction was achieved with log 3.6. By making further changes and increasing the disinfection cycles, it was possible to increase the germ reduction to log 4.7. If these values are confirmed and can be improved by further modifications (e.g. increasing the plasma concentration), cold plasma technology represents a very good alternative to conventional disinfection methods.

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Due to the corona pandemic, the demand for efficient and fast-acting disinfection measures is high. In this work, the disinfecting potential of a dry fogging technology (Apollon Biotech GmbH, Germany) was investigated for the possibility of disinfection of vehicles for passenger transport. This could represent a new approach for processing emergency vehicles or local passenger transport vehicles quickly and cost-effectively. A public bus was used as a model for a passenger transport vehicle (Ferienfahrschule Hense GbR, Germany). This vehicle was tested at predetermined points before and after dry-fog disinfection with swab and contact plate samples. In addition, contaminated sample tiles (Staphylococcus aureus ATCC 6538; 5x104 CFU) were placed at some locations in order to be able to record a standardized germ reduction. To determine the decontamination effect of the air in the vehicle, active airborne germ measurements were performed. In the airborne germ measurement, our results indicated a reduction of approx. 68% of the microbiological air contamination. Screening of the total contamination of the bus at several selected sites showed an average load of approximately 348 CFU per test site. After disinfection, the average bacterial count was reduced to approx. 18 CFU per test site. This disinfecting effect could also be shown with the standardized test tiles. An efficiency level of between log 0.8 and 3.7 was obtained at the various test sites.