Process control of surface disinfection based on functionalized proteoliposomes
IGF 17922 N
In hygienically demanding areas, such as food and pharmaceutical industry, cosmetics and health sector, hygiene and disinfection plans are an important part of quality management systems. These plans determine the regular implementation of cleaning and disinfection procedures. To verify the success of cleaning and disinfection processes random end product controls are carried out routinely. Because there are no suitable fast methods available at present the disinfection success can only be verified by contact plates or swab testing. However, end product controls are very time consuming and expensive as they have to be performed by external laboratories. The long duration of the investigation makes it impossible to apply any corrective actions of disinfection in a timely manner.
Therefore, the aim of the project was the development of a fast method for an easy and fast self-monitoring of surface disinfection processes based on proteoliposomes including a selfquenching fluorescent dye.
Microorganisms have a membrane containing target structures for disinfectant active substances. These target structures can be simulated by proteoliposomes. Therefore they were used for the development of a test monitor.
Using various lipids and proteins proteoliposomes were prepared. Functionalization of proteoliposomes was carried out with a fluorescent dye which had the property of fluorescence quenching (no fluorescence) depending on high concentrations but emitted a strong fluorescence signal after dilution. Immobilization of proteoliposomes was carried out on a carrier matrix by embedding the proteoliposomes in a hydrogel. The test monitor was placed on the surface to be disinfected. By the action of the disinfectant the proteoliposomes were destroyed analogously to the microorganisms and the included dye was released. The quality of the disinfection process could then be assessed by the intensity of fluorescence of the released dye correlating with the level of germ reduction and visualized with UV-light.
Thus, a process control was developed that can be used as part of on-site self-monitoring in quality management systems, in order to detect possible failures in the disinfection process promptly and if necessary to initiate corrective actions immediately.
The research report is available on request from FRT.