Vol.56 No.3 May 2008

Antifungal activity of micafungin against clinical isolates of Candida and Aspergillus species -Second biennial surveillance report-

Intetsu Kobayashi¹⁾, Makoto Suzuki¹⁾, Takeshi Saika¹⁾, Fumiaki Ikeda²⁾, Yasuhiro Hori²⁾, Satoru Matsumoto³⁾, Ikuo Kawamura⁴⁾, Takashi Yoshiyasu⁴⁾ and Hisanori Horita⁴⁾

¹⁾Chemotherapy Division, Mitsubishi Chemical Medience Corp., 3-30-1 Shimura, Itabashi-ku, Tokyo, Japan
²⁾Product Marketing, Astellas Pharma Inc.
³⁾Pharmacology Research Labs., Astellas Pharma Inc.
⁴⁾Post Marketing Medical Research, Astellas Pharma Inc.

Abstract

In a postmarketing surveillance study for comparison with previous results, we determined the susceptibility to micafungin(MCFG) and other antifungal drugs -amphotericin B, fluconazole, itraconazole, miconazole, flucytosine, caspofungin, and voriconazole- for 690 strains (410 of 6 Candida species and 280 of 4 Aspergillus species), isolated from patients with suspected fungal infection visiting medical facilities in Japan between January 2005 and December 2006. MIC levels against Candida and Aspergillus species were determined according to the broth microdilution, as specified by Clinical and Laboratory Standards Institute(CLSI) documents M27-A and M38-P. For Candida species, MIC levels for score 2, currently being standardized by the CLSI as criteria for MIC determination of echinocandin antifungal drugs against Candida species, were determined for reference in addition to score 0. MIC₉₀ levels of MCFG against 130 Candida albicans isolates, including those fluconazole-resistant were 0.015 μg/mL, and against 50 isolates each of Candida tropicalis 0.03 μg/mL, Candida glabrata 0.015 μg/mL, Candida parapsilosis 2 μg/mL, Candida krusei 0.25 μg/mL, and Candida guilliermondii 4 μg/mL. MIC₉₀ levels of MCFG against 100 Aspergillus fumigatus isolates were 0.015 μg/mL and against another 180 Aspergillus isolates 0.008 to 0.03 μg/mL. MIC levels of MCFG against Candida and Aspergillus species determined in this study remained unchanged compared to those against isolates sampled in 2001-2002 and 2003-2004. MIC levels of MCFG for score 2 tended to be lower than those for score 0, with a markedly significant difference between scores observed in MIC against C. guilliermondii. These findings indicate that MCFG exerts the most potent antifungal activity of antifungal drugs studied and that the susceptibility of target fungi to MCFG remained high compared to previous biennial surveillance conducted from 2001.

Key word

Candida, Aspergillus, micafungin, antifungal activity

Received

December 7, 2007

Accepted

March 4, 2008

Jpn. J. Chemother. 56 (3): 344-352, 2008