Related Experiment Video
Updated: Aug 6, 2026
Broth Microdilution In Vitro Screening: An Easy and Fast Method to Detect New Antifungal Compounds
Published on: February 14, 2018
Comparative study of disc diffusion and microdilution methods in susceptibility testing of micafungin against Candida
M Ramírez1, M C Serrano, C Castro
1Servicio de Microbiología Clínica, Hospital Universitario de Valme Seville 41014, Spain.
Objectives:
To compare the Clinical Laboratory Standards Institute CLSI M44-A disc diffusion (DD) and M27-A2 broth microdilution (MD) methods for determining the susceptibility of Candida spp. to micafungin (FK463).
Patients And Methods:
A total of 355 clinical yeast isolates including 270 Candida albicans, 45 Candida glabrata, 24 Candida krusei, 11 Candida tropicalis and 5 Candida parapsilosis were studied. The MIC of micafungin was determined by following the CLSI M27-A2 guidelines (MD). Endpoints were defined as the lowest concentration of micafungin resulting in partial inhibition (IC(50)) of visual growth after 24/48 h of incubation at 35 degrees C. Final concentrations were 0.008-4 mg/L of micafungin. DD testing was performed using a CLSI M44-A document with 2.5 mug micafungin discs. Zone diameter endpoints were read after 24/48 h of incubation at 35 degrees C. Arbitrary breakpoints were 4 mg/L for MD and 15 mm for DD.
Results:
The best correlation was observed when we read MD 48 h/DD 24 and 48 h (97%). When the reading was MD 24 h/DD 24 and 48 h the percentage of correlation was 95.2%.
Conclusions:
The DD method performs well for testing the susceptibility of Candida spp. to micafungin. More studies involving more Candida strains with elevated MIC values are needed.
