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The increasing incidence of invasive fungal diseases ( IFD), most of all invasive aspergillosis ( IA) in immunocompromised patients emphasises the need to improve the diagnostic tools for detection of fungal pathogens. We investigated the diagnostic performance of a multifungal DNA-microarray detecting 15 different fungi [ Aspergillus, Candida, Fusarium, Mucor, Rhizopus, Scedosporium and Trichosporon species (spp.)] in addition to an Aspergillus specific polymerase chain reaction ( PCR) assay. Biopsies, bronchoalveolar lavage and peripheral blood samples of 133 immunocompromised patients (pts) were investigated by a multifungal DNA-microarray as well as a nested Aspergillus specific PCR assay. Patients had proven ( n = 18), probable ( n = 29), possible ( n = 48) and no IFD ( n = 38) and were mostly under antifungal therapy at the time of sampling. The results were compared to culture, histopathology, imaging and serology, respectively. For the non- Aspergillus IFD the microarray analysis yielded in all samples a sensitivity of 64% and a specificity of 80%. Best results for the detection of all IFD were achieved by combining DNA-microarray and Aspergillus specific PCR in biopsy samples (sensitivity 79%; specificity 71%). The molecular assays in combination identify genomic DNA of fungal pathogens and may improve identification of causative pathogens of IFD and help overcoming the diagnostic uncertainty of culture and/or histopathology findings, even during antifungal therapy. [ABSTRACT FROM AUTHOR]

During several decades microscopy and culture based methods have been the most important techniques for the detection of fungal infections. Culture, though often slow, sometimes insensitive and sometimes confusing with respect to contamination or colonization, may yield the specific aetiological agent, and may allow susceptibility testing to be performed. However, molecular detection and identification using PCR for the amplification of fungal DNA from tissue is being applied more and more frequently for the early diagnosis and identification of fungal pathogens. Other tools such as fluorescence in situ hybridization (FISH) or DNA microarrays have also been developed and their performance is currently being evaluated. Since standardization and validation for most of these newer techniques are still lacking the combination of various diagnostic tools is still mandatory to allow earlier diagnosis of systemic fungal infections. [ABSTRACT FROM AUTHOR]