Background: Concerns have been raised if fluconazole can be used for empirical treatment when positive blood cultures with Candida are reported. We investigated the in vitro activity of eight antifungal drugs of Candida species isolated from invasive infections with special reference to the non-C. albicans species. Methods: 309 strains were prospectively isolated during a 6-month period (07-2005 - 01-2006). MICs were determined for amphotericin B (AmB), flucytocine (5FC), fluconazole (FLU), itraconazole (IT), voriconazole (VOR), posaconazole (POS), caspofungin (CAS) and BAL 4815 (BAL). Microdil. testing was done in accordance with CLSI M27-A2 in RPMI 1640 MOPS broth + L-glutamine without bicarbonate and incubated at 35oC for 24 hours. The MIC was determined visually and spectrophotometrically as the lowest concentration of drug showing absence of growth or ≥ 50% reduction of growth compared with that of the growth control for AMB, and 5FC and azoles, respectively. Results: Species distribution was C. albicans (61%), C. glabrata (21%), C. tropicalis (5%) and C. parapsilosis (4%). Only 1.5% of C. albicans was resistant to FLU (MIC >256) compared to 10% of the non-C. albicans isolates. Among the FLU susceptible (MIC8) isolates (n=24) the MIC90 and MIC range for CAS, FLU and VOR was 0.5, 0.016-1; 256, 16->64; 1, 0.064-1mg/L respectively. Conclusions: To cover FLU resistant non-C.albicans in initial therapy for invasive candidiasis, caspofungin is an excellent option in terms of in vitro susceptibility. VOR also demonstrated a low MIC although it should be recognized that in FLU resistant isolates the VOR MIC is several fold higher than in FLU susceptible isolates.
Full conference title:
46th Interscience Conference on Antimicrobial Agents and Chemotherapy
- ICAAC 46th