Amphotericin B resistance testing of Candida spp.: a comparison of methods

Several methods of susceptibility testing were compared for their ability to detect amphotericin B resistance among yeast isolates, including isolates known to be amphotericin-B-resistant in an animal model. A microtitre MIC method using antibiotic medium no. 3 and Etest strips were able to discriminate susceptible and resistant isolates. A disc susceptibility test was also able to identify resistant isolates and this method may be suitable for routine use as a screening test. A survey of resistance in 644 clinical isolates showed that the incidence of elevated MICs (greater than or equal to 0.25 mg/L) was only 1.2%.