Evaluation of a Spectrophotometric Broth Microdilution Method for Determining Fluconazole Susceptibility of Candida albicans: Influence of RPMI and RPMI-2% Glucose on the Selection of Endpoint Criteria / 대한진단검사의학회지
The Korean Journal of Laboratory Medicine
; : 188-195, 2002.
Article
en Ko
| WPRIM
| ID: wpr-182213
Biblioteca responsable:
WPRO
ABSTRACT
BACKGROUND: Minimum inhibitory concentration (MIC) endpoint determination is the major varia-tion source for the fluconazole susceptibility test, especially for Candida albicans. In this study, we evaluated spectrophotometric broth microdilution methods using RPMI 1640 and RPMI supple-mented with 18 g of glucose per liter (RPMI-2% glucose) for determining fluconazole susceptibility of C. albicans. METHODS: A total of 129 clinical isolates of C. albicans were tested by the broth microdilution method using RPMI and RPMI-2% glucose. The MIC endpoint was calculated objectively with the spectrophotometer set at 405 nm. These results were compared to those by the National Commit-tee for Clinical Laboratory Standards (NCCLS) macrodilution method and the agar dilution method. RESULTS: The mean absorbances in the drug-free wells in RPMI and RPMI-2% glucose were 0.208 +/- 0.014 and 0.316 +/- 0.061, respectively, at 24 h and 0.339 +/- 0.094 and 0.530 +/- 0.104, respectively, at 48 h (P < 0.01). The agreement of the microdilution method with the RPMI within two doubling dilutions of the macrodilution reference were 91.5% (118/129) at 24 h and 76.7% (99/129) at 48 h. The percentage of agreement in the microdilution method with the RPMI-2% glucose were significantly higher: 100% (129/129) at 24 h and 99.2% (128/129) at 48 h (P < 0.01). In addition, the MIC endpoints were easier to detect in RPMI-2% glucose, because of the greater difference in absorbance in between grown wells and fluconazole-inhibited wells (P < 0.01). CONCLUSIONS: The spectrophotometric microdilution method with RPMI-2% glucose may have an excellent agreement with the NCCLS broth macrodilution method and may provide more easily determined MIC endpoints for fluconazole susceptibility testing for C. albicans.
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Texto completo:
1
Índice:
WPRIM
Asunto principal:
Candida
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Candida albicans
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Pruebas de Sensibilidad Microbiana
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Fluconazol
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Determinación de Punto Final
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Agar
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Glucosa
Tipo de estudio:
Guideline
Idioma:
Ko
Revista:
The Korean Journal of Laboratory Medicine
Año:
2002
Tipo del documento:
Article