The final report will be published here in German language after completion.

Short report:

The aim of the research project is an in-situ rapid detection of hygiene-relevant germs on internal and external endoscope surfaces according to Annex 10 of the Guideline for the Validation of Endoscope Reprocessing Procedures.

The detection of individual hygiene-relevant germs is based on the selective labelling with aptamers of DNA, which can be quantitatively separated from the germs after labelling by thermal denaturation and eluted from the endoscope. Recovered aptamers are bound by hybridization to complementary DNA sections (oligonucleotides) on specific evaluation fields for the detection of S. aureus, Enterobacteriaceae, Pseudomonads and Enterococci in one evaluation unit.

Aptamers are detected by a duplex amplification method. Spherical DNA hybrid aggregates (SDHA) first bind to the aptamers, which carry numerous initiator oligonucleotides in addition to the oligonucleotides necessary for binding to aptamers. In a subsequent step, numerous metastable Carbon Quantum Dot functionalized oligonucleotides are bound to the initiator oligonucleotides in a hybridization chain reaction, resulting in high-molecular fluorescent products that can be visually evaluated without further aids when excited with UV light.

The cleaning and hygiene service providers increasingly entrusted with the reprocessing of medical devices and the reprocessing units for medical devices operated by the medical institutions themselves are provided with an in-house and inexpensive rapid detection system for independent in-house testing of the reprocessing quality of flexible endoscopes.