Use of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry for Caspofungin Susceptibility Testing of Candidaand AspergillusSpecies

ABSTRACTMatrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) was evaluated for testing susceptibility to caspofungin of wild-type and fksmutant isolates of Candidaand Aspergillus. Complete essential agreement was observed with the CLSI reference method, with categorical agreement for 94.1% of the Candidaisolates tested. Thus, MALDI-TOF MS is a reliable and accurate method to detect fungal isolates with reduced caspofungin susceptibility.