8 0 Requirement: Rapid detection of pathogenic agents Infections by yeasts and mold fungi lead to severe illnesses, especially in immunocompromized and patients in intensive care. With a mortality rate of between 30 and more than 80 percent, the rapid detection of a pathogen and its resistance spectrum plays a particularly decisive role in the success of treatment. The classical detection of pathogens using culture- based methods (Microdilution, Etest® ) can take up to 14 days for yeasts and mold fungi. Furthermore, it is known from clini- cal studies that phenotypical resistance testing contains an er- ror of up to 15 percent. Culturing often fails completely, even when the patient displays clear clinical symptoms. In these cases, a therapy on suspicion, which cannot be specifically adapted to the relevant pathogen, has to be initiated. For this reason, molecular biology methods such as sequenc- ing or PCR are increasingly being used for the identification of pathogens. However, these methods have a limited multiplex capability. This means that only a small number of the multi- tude of commonly occurring pathogens or resistances can be tested concurrently (≤ 10 parameters). As a result, numerous tests become necessary, which reduces the time advantage of the method. Microarrays as the diagnostic tool of choice It is possible to compensate for this diagnostic gap by using microarrays, which enable the simultaneous examination of up to several thousand parameters. To date, such tests have been rarely used in routine diagnostics due, among other things, to the high experimental and instrumental efforts involved in the processing of microarrays. These problems can be minimized by the application of automated sample prepa- ration steps that combine the entire testing process into a so- called lab-on-a-chip (LOC). Aim: A fully integrated lab-on-a-chip system The Fraunhofer IGB and the Institute of Interfacial Process Engineering and Plasma Technology (IGVP) of the University of Stuttgart, in cooperation with partners from medicine, science and industry and in the context of the BMBF-funded research project “FYI-Chip – Fungi Yeast Identification”, are therefore developing a fully integrated lab-on-a-chip system (LOC) for the rapid identification of fungal infections in respiratory secretions and primarily sterile body fluids of immunocompro- mized patients. To this end, the scientists at the Fraunhofer IGB and IGVP are working closely with the company Euroim- mun, based in Lübeck, Germany, with doctors at the Heart and Diabetes Centre North Rhine-Westphalia, as well as with developers at the Reutlinger Multi Channel Systems MCS GmbH and Robert Bosch GmbH, Gerlingen. Their aim is to combine the individual functional components such as sample preparation, microfluidics and the detection of pathogenic DNA into a single fully integrated LOC. Results To date, it is possible to detect 45 relevant yeast and fun- gal pathogens (including Candida spp. or Aspergillus spp.) definitively and with high sensitivity using newly developed PCR systems and DNA probes on microarrays at the IGVP. In order to identify this many pathogens, PCR systems have been FYI-CHIP – DETECTION OF HUMAN YEAST AND FUNGAL PATHOGENS USING A LAB-ON-A-CHIP DEVICE Dipl.-Biol. Linda Mayer, Priv.-Doz. Dr. sc. nat. Susanne Bailer, Priv.-Doz. Dr. rer. nat. Steffen Rupp 1 2 MEDICINE 10 μm