Vol.54 No.4 July 2006

Susceptibility survey of fresh clinical isolates of Candida and Aspergillus species to micafungin and seven other antifungal agents

Intetsu Kobayashi¹⁾, Masahiro Wakasugi²⁾, Fumiaki Ikeda²⁾, Miyuki Hasegawa¹⁾, Makoto Suzuki¹⁾, Hisanori Horita²⁾ and Kiyoshi Sakai²⁾

¹⁾Chemotherapy Division, Mitsubishi Kagaku Bio-Clinical Laboratories, Inc.,
3-30-1 Shimura, Itabashi-ku, Tokyo, Japan
²⁾Post Marketing Product Development, Astellas Pharma Inc.

Abstract

We tested 690 strains-410 strains of 6 Candida species and 280 strains of 4 Aspergillus species-isolated from patients suspected of having fungal infections in medical institutions in Japan for about 2 years between February 2003 and November 2004 for susceptibility to micafungin and 7 other antifungal agents. MICs of these antifungal agents for Candida species and Aspergillus species were determined by broth microdilution based on NCCLS M27-A and NCCLS M38-P. Antifungal agents tested were micafungin (MCFG), amphotericin B (AMPH-B), fluconazole (FLCZ), itraconazole (ITCZ), miconazole (MCZ), 5-fluorocytosine (5-FC), caspofungin (CAS), and voriconazole (VRCZ). MICs of MCFG for 130 strains of Candida albicans, including FLCZ-resistant strains, and 50 strains each of Candida tropicalis and Candida glabrata were 0.03 μg/mL or less and were the lowest in all antifungal agents tested. MICs of MCFG for 50 strains each of Candida parapsilosis and Candida guilliermondii were 2-8 μg/mL and some strains exhibited slightly higher MICs. MICs of VRCZ for these strains were 0.25 μg/mL or less and were the lowest in all antifungal agents tested.
MIC₉₀s of MCFG for 100 strains of Aspergillus fumigatus were 1/16 those of ITCZ and VRCZ and 1/32 those of CAS. A similar trend was seen in the other 180 strains of Aspergillus species, i.e., MICs of MCFG for these strains were the lowest in all antifungal agents tested, and no strains showed more than 0.03 μg/mL MICs.
These results suggest that the antifungal activity of MCFG against Candida and Aspergillus species isolated in recent years is the most potent compared to those of antifungal agents currently available in Japan and CAS used in the United States and Europe, and that MCFG is useful in the treatment of mycosis due to these fungi.

Key word

Candida, Aspergillus, micafungin, antifungal activity

Received

March 20, 2006

Accepted

May 24, 2006

Jpn. J. Chemother. 54 (4): 308-314, 2006