Evaluation of the in vitro activity of caspofungin against bloodstream isolates of Candida species from cancer patients: comparison of Etest and NCCLS reference methods.

The in vitro activity of caspofungin (CAS) was compared with the activity of fluconazole, itraconazole and amphotericin B against 178 bloodstream Candida spp. from cancer patients. The activities were assessed using the reference NCCLS M-27A microdilution method and the Etest method. With both the NCCLS microdilution reference method and the Etest method, CAS was the most active agent (MIC90s 0.19-0.5 mg/l) against Candida albicans, C. glabrata and C. tropicalis. CAS showed substantial activity against azole-resistant Candida. The percentages of agreement within +/-2 dilutions between the NCCLS reference microdilution method and Etest MICs ranged from 81 to 97%. CAS showed good in vitro activity against invasive azole-susceptible and azole-resistant Candida isolates. The CAS Etest MICs correlated well with the NCCLS reference MICs and may provide more choice for laboratories in assessing the activity of antifungal agents. The clinical correlation of these in vitro observations needs to be established. Copyright 2002 Elsevier Science B.V. and International Society of Chemotherapy