Antifungal Susceptibilities to Fulconazole and Itraconazole for Candida Species Recovered from Blood Cultures over a 5-Year Period

Shin, Jong Hee; Lim, Woo Hyun; Shin, Dong Hyeon; Suh, Soon Pal; Ryang, Dong Wook

Abstract

BACKGROUND
Fluconazole and itraconazole, the azole-derivative antifungal agents, have been commonly used for the treatment of candidiasis. We studied the comparative activities of fluconazole and itraconazole against isolates of Candida species recovered from blood cultures in Chonnam National University Hospital between 1994 and 1998.
METHODS
One hundred twenty-four bloodstream isolates of Candida species (32 C. albicans, 36 C. parapsilosis, 19 C. tropicalis, 12 C. glabrata, 10 C. pelliculosa, 7 C. guilliermondii, 5 C. lipolytica, and 3 others) from 124 patients were tested. Minimal inhibitory concentrations (MICs) of fluconazole (0.12~64microgram/mL) and itraconazole (0.03~16 microgram/mL) for each isolate were determined by the NCCLS broth macrodilution method.
RESULTS
Fluconazole MICs were >64 microgram/mL for 4.8% (6/124) of the isolates and 16~32 microgram/mL for the 8.9% (11/124) isolates. Itraconazole MICs were >1 microgram/mL for 16% (16/124) and 0.25~0.5 microgram/mL for 21.0% (26/124) of the isolates. Candida species for which the fluconazole MICs were higher, were in general more resistant to itraconazole (P<0.05). There were species-related differences in MIC50:those for C. albicans, C. parapsilosis and C. tropicalis were lower than those for other species. MICs of fluconazole and itraconazole for each species did not change during the 5-year period, but resistance to fluconazole (>64 microgram/mL) or itraconazole (> 1 microgram/mL) was observed in 4.5% (2/44) of isolates obtained from 1994 to 1996, and increased to 17.5% (14/80) of isolates recovered in 1997 to 1998 (P<0.05).
CONCLUSION
This data showed that itraconazole MICs were proportionally higher for Candida isolates with high fluconazole MICs, and Candida species with fluconazole or itraconazole resistance increased in the latter two years, although MICs of fluconazole and itraconazole for each species did not change during the 5-year span.