Reinhard Beyer1, Kathrin Spettel2, Iris Zeller2, Cornelia Lass-Flörl3, Dagmar Achleitner4, Robert Krause5,6, Petra Apfalter7, Walter Buzina8, Joseph Strauss1,9, Christa Gregori1, Christoph Schüller1,9, Birgit Willinger2. 1. Department of Applied Genetics and Cell Biology (DAGZ), University of Natural Resources and Life Sciences, Vienna (BOKU), Austria. 2. Division of Clinical Microbiology, Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria. 3. Division of Hygiene and Medical Microbiology (HMM), Medical University of Innsbruck, Innsbruck, Austria. 4. Division of Medical Microbiology, University Hospital Salzburg (SALK), Salzburg, Austria. 5. Section of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Medical University of Graz, Graz, Austria. 6. BioTechMed-Graz, Graz, Austria. 7. Institute for Hygiene, Microbiology and Tropical Medicine, Ordensklinikum Linz Elisabethinen, Linz, Austria. 8. R&D Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria. 9. Research Platform Bioactive Microbial Metabolites (BiMM), Department of Applied Genetics and Cell Biology (DAGZ), University of Natural Resources and Life Sciences, Vienna, Austria.
Abstract
BACKGROUND: Candida-associated infections put a significant burden on western healthcare systems. Development of (multi-)resistant fungi can become untreatable and threaten especially vulnerable target groups, such as the immunocompromised. OBJECTIVES: We assessed antifungal susceptibility and explored possible influence factors of clinical Candida isolates collected from Austrian hospitals between 2007 and 2016. METHODS: Thousand three hundred and sixty clinical Candida spp. isolated from blood cultures were subjected to antifungal susceptibility testing (AFST) in a liquid-handling aided continuous microdilution assay. We tested against fluconazole, voriconazole, posaconazole, itraconazole, isavuconazole, anidulafungin, caspofungin and micafungin according to EUCAST with additional recording of growth curves. We performed rigid quality control on each assay via growth curve assessment and included two standard reference strains. Minimal inhibitory concentrations (MIC) were quantified according to EUCAST guideline E.DEF 7.3.1, and susceptibility was evaluated using EUCAST clinical breakpoints. RESULTS: The isolate collection consisted of Candida albicans (59%), C. glabrata (19%), C. parapsilosis (9%), C. tropicalis (5%) and C. krusei (3%) and few other Candida species and fungi (5%). During the observed time period, species abundance and antifungal resistance rates remained constant. Multi-resistance was rare and we found no single isolate which was resistant to both azoles and echinocandins. Within the antifungal resistance profile of our strain collection, we observed clusters along species boundaries. CONCLUSIONS: Over the last decade, the distribution of Candida species and its level of antifungal resistance remained constant in Austria. Our data compare well with other European countries. Principal component analysis of the susceptibility profile of this collection revealed species-specific clusters and substantial intra-species variation, especially for C. glabrata.
BACKGROUND:Candida-associated infections put a significant burden on western healthcare systems. Development of (multi-)resistant fungi can become untreatable and threaten especially vulnerable target groups, such as the immunocompromised. OBJECTIVES: We assessed antifungal susceptibility and explored possible influence factors of clinical Candida isolates collected from Austrian hospitals between 2007 and 2016. METHODS: Thousand three hundred and sixty clinical Candida spp. isolated from blood cultures were subjected to antifungal susceptibility testing (AFST) in a liquid-handling aided continuous microdilution assay. We tested against fluconazole, voriconazole, posaconazole, itraconazole, isavuconazole, anidulafungin, caspofungin and micafungin according to EUCAST with additional recording of growth curves. We performed rigid quality control on each assay via growth curve assessment and included two standard reference strains. Minimal inhibitory concentrations (MIC) were quantified according to EUCAST guideline E.DEF 7.3.1, and susceptibility was evaluated using EUCAST clinical breakpoints. RESULTS: The isolate collection consisted of Candida albicans (59%), C. glabrata (19%), C. parapsilosis (9%), C. tropicalis (5%) and C. krusei (3%) and few other Candida species and fungi (5%). During the observed time period, species abundance and antifungal resistance rates remained constant. Multi-resistance was rare and we found no single isolate which was resistant to both azoles and echinocandins. Within the antifungal resistance profile of our strain collection, we observed clusters along species boundaries. CONCLUSIONS: Over the last decade, the distribution of Candida species and its level of antifungal resistance remained constant in Austria. Our data compare well with other European countries. Principal component analysis of the susceptibility profile of this collection revealed species-specific clusters and substantial intra-species variation, especially for C. glabrata.