Evaluation of Spectrophotometric Broth Microdilution Methods for Determining Antifungal Susceptibilities of Aspergillus Species.
- Author:
Mi Ra PARK
1
;
Jong Hee SHIN
;
Jeong Won SONG
;
Young Kyu PARK
;
Duck CHO
;
Seung Jung KEE
;
Myung Geun SHIN
;
Soon Pal SUH
;
Dong Wook RYANG
Author Information
1. Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea. shinjh@chonnam.ac.kr
- Publication Type:Original Article
- Keywords:
Spectrophotometric broth microdilution method;
Aspergillus;
Amphotericin B;
Itra-conazole
- MeSH:
Amphotericin B;
Aspergillus*;
Fungi;
Itraconazole;
Microbial Sensitivity Tests;
Niger
- From:The Korean Journal of Laboratory Medicine
2004;24(5):301-307
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: A spectrophotometric approach to minimum inhibitory concentration (MIC) determination for filamentous fungi may provide an objective and rapid MIC reading, and quantify the hyphal growth of molds. In this study, we evaluated two spectrophotometric broth microdilution methods (SBM) to determine amphotericin B and itraconazole MICs for Aspergillus species isolated from clinical specimens. METHODS: A total of 80 clinical isolates (20 A. fumigatus, 20 A. flavus, 18 A. niger, 20 A. terreus, and 2 A. nidulans) were tested for amphotericin B and itraconazole susceptibility by the broth microdilution method. The MIC endpoint was calculated by the spectrophotometer with microplate reader (SBM-Spec method) or colorimetric XTT (tetrazolium dye) method (SBM-XTT method). The results of the SBM method were compared with those of NCCLS M38-A broth microdilution method. RESULTS: The MICs of amphotericin B by the NCCLS M38-A method ranged from 0.125 to 8 g/mL, and those of itraconazole ranged from 0.25 to 2micrograms/mL. The agreement of SBM-Spec and SBM-XTT methods within one dilution of the NCCLS M38 reference were 98.8% and 96.3% for the ampho-tericin B, and 98.8% and 100% for itraconazole, respectively. The agreements between SBM-Spec and SBM-XTT methods were 97.5% for amphotericin B and 98.8% for itraconazole. CONCLUSIONS: In antifungal susceptibility testing of Aspergillus species, the SBM method includ-ing SBM-Spec and SBM-XTT methods showed high levels of agreements with the NCCLS M38-A method. The SBM methods can be useful in the clinical laboratory.
