Abstract
To evaluate the in vitro susceptibility of Fusarium to isavuconazole, 75 clinical isolates were identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry and then tested with a broth microdilution method (EUCAST) and the gradient concentration strip (GCS) technique. The activity of isavuconazole overall was shown to be limited, with an MIC(50) of >16 μg/ml, without significant differences between the species complexes. The categorical agreement between GCS and EUCAST was 97.4% to 100%, making the GCS as a valuable alternative.