Comparative evaluation of disk diffusion with microdilution assay in susceptibility testing of caspofungin against Aspergillus and Fusarium isolates.
We compared the disk diffusion and broth microdilution methods for susceptibility testing of caspofungin against Aspergillus (n = 78) and Fusarium (n = 22) isolates. Microdilution testing followed the NCCLS M-38P guidelines but was performed in antibiotic medium 3 supplemented to 2% glucose (AM3). Disk diffusion assays were performed on AM3 agar plates with a 2- micro g caspofungin disk. By both methods, caspofungin showed favorable activity against Aspergillus isolates and no activity against Fusarium isolates. In the disk-based format, intrazonal growth that was not influenced by the drug concentration gradient was consistently observed for all of the Aspergillus isolates tested.
Division of Infectious Diseases, Department of Internal Medicine, Center for the Study of Emerging and Reemerging Pathogens, University of Texas Medical School, Houston, Texas 77030, USA. sarikan@metu.edu.tr
Sevtap
S
Arikan
Victor
V
Paetznick
John H
JH
Rex
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001228:Aspergillosis / Q000382:microbiology; D001230:Aspergillus / Q000187:drug effects*; D000077336:Caspofungin; D054714:Echinocandins; D005670:Fusarium / Q000187:drug effects*; D055666:Lipopeptides; D008826:Microbial Sensitivity Tests; D009181:Mycoses / Q000382:microbiology; D010455:Peptides; D010456:Peptides, Cyclic
D000900:Anti-Bacterial Agents; D054714:Echinocandins; D055666:Lipopeptides; D010455:Peptides; D010456:Peptides, Cyclic; D000077336:Caspofungin