Development of anidulafungin for disk diffusion susceptibility testing against Candida spp.
A disk diffusion (DD) method has been standardized by the Clinical and Laboratory Standards Institute (M44-A) to test Candida susceptibilities for some azoles (fluconazole and voriconazole). The DD method using anidulafungin, a new echinocandin, was initially developed here using Candida spp. (75 strains) and candidate anidulafungin disk concentrations of 1, 2, 5, and 10 microg with or without dimethyl sulfoxide (DMSO) (0.05-1%) and with or without polysorbate 80 (P-80, 0.002-2%). The 2-microg disks (with 1% DMSO and 0.1% P-80) produced acceptable correlation statistics (r = 0.84-0.85 ) when compared with reference MIC results, and this disk was optimal for testing all Candida spp. Good separation of Candida parapsilosis (least anidulafungin-susceptible species) from the more susceptible yeast species and a potential susceptibility breakpoint near the preferred reproducible zone diameter of > or = 15 mm were achieved for all tested yeast species.
Jones
Ronald N
RN
JMI Laboratories, North Liberty, IA 52317, USA. ronald-jones@jmilabs.com
Kirby
Jeffrey T
JT
Messer
Shawn A
SA
Sheehan
Daniel J
DJ
D000077612:Anidulafungin; D000935:Antifungal Agents / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects*; D054714:Echinocandins; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods*; D010456:Peptides, Cyclic / Q000494:pharmacology*; D013223:Statistics as Topic
D000935:Antifungal Agents; D054714:Echinocandins; D010456:Peptides, Cyclic; D000077612:Anidulafungin