[Resistant fungi]

Particularly in the area of hematology/oncology and intensive care medicine, infections due to resistant fungi are to be expected. Emergence of resistance in fungi is a less dynamic process than in bacteria; it can, however, have an equally important impact on treatment strategies. In the following article, the most important resistance patterns of yeasts and molds (Candida albicans , Aspergillus fumigatus, the order Mucorales and the genus Fusarium) will be presented and discussed. Their diagnosis mostly being based on blood cultures, resistance testing for yeasts is usually readily available. Culture-based therapeutic adjustments in mold infections are, however, only rarely possible, as most antifungal therapies for these infections are initiated on an empirical basis after identification of typical infiltrates on a CT scan. Response to therapy is then evaluated on the basis of clinical signs and symptoms in combination with follow-up CT scans. In case of therapeutic failure or appearance of suspicious infiltrates under antifungal prophylaxis, an open or CT-guided biopsy is recommended to allow efficient adaptation of antifungal treatment. In individual cases, particularly in patients diagnosed with mucormycosis, resection of the focus of infection may be necessary to achieve a satisfactory treatment response.