Susceptibility testing of Candida glabrata clinical strains to echinocandins using SensititreTM YeastOneTM system

Abstract

Objective. To determine susceptibility of C. glabrata isolates to anidulafungin, caspofungin and micafungin using the SensititreTM YeastOneTM system. Materials and Methods. C. glabrata isolates were taken prospectively from clinical specimens or from strains collections in the participating sites. Susceptibility determination was performed using SensititreTM YeastOneTM (YO10 panel) according to the manufacturer’s guidance, and results were interpreted with M27-A3 CLSI guidelines. Susceptibility of C. glabrata to fluconazole was also determined in order to assess possible correlations of echinocandins and fluconazole minimal inhibitory concentrations (MICs) in resistant strains. Results. A total of 59 C. glabrata strains were tested. The strains were isolated mostly from peripheral blood (44%). Among clinically significant medical conditions/risk factors and co-morbidities, central venous catheter, solid tumors, and abdominal surgery were identified in 20 (33.9%), 19 (32.2%), and 14 (23.7%) patients, respectively. Most MIC values of echinocandins were 0.015 and 0.03 mg/L. Caspofungin has slightly higher MIC values than those of anidulafungin and micafungin. No isolates were resistant to any of the echinocandins. The only 2 patients were receiving echinocandin therapy at the time of taking biosamples (with no reported information about treatment efficacy); those strains were also susceptible to all echinocandins. All C. glabrata strains were susceptible dose-dependent to fluconazole with MIC values between 2 and 32 mg/L. Conclusions. All of the echinocandins have a high and comparable in vitro activity against C. glabrata, including strains which are susceptible dose-depended to fluconazole. More prospective studies are needed to investigate the long-term trends in susceptibility profiles of pathogens causing candidiasis, especially C. glabrata.