[CHROMAgar Candida with fluconazole: comparison with microdilution techniques].
BACKGROUND
The increasing incidence of fungal infections and the reported emergence of resistance to antifungal agents call for the development of techniques for in vitro measurement of antifungal susceptibility that will enable prediction of clinical outcome in patients suffering from these infections. METHODS. Susceptibility to fluconazole was tested in 156 clinical yeast isolates (109, Candida albicans; 19, C. parapsilosis; 12, C. glabrata; 11, C. tropicalis; 2, C. krusei; 1, C. pelliculosa; 1, C. lambica, and 1, Saccharomyces cerevisiae) and two control strains (C. krusei ATCC 6258 and C. parapsilosis ATCC 22019) using a simple screening method, CHROMAgar Candida with fluconazole (8 micro g/ml). This method was compared with two broth microdilution techniques: the reference method (NCCLS, document M27-A) and Sensititre(TM) YeastOne.


RESULTS
Sensititre(TM) YeastOne showed close agreement with NCCLS M27-A results for all species (C. albicans and non albicans). CHROMAgar Candida with fluconazole (8 micro g/ml) yielded results matching those of the two broth microdilution methods for sensitive strains and strains highly resistant to fluconazole (C. krusei and C. glabrata), but performed less well with strains displaying dose-dependent susceptibility.


CONCLUSIONS
These data suggest that CHROMAgar Candida with fluconazole (8 micro g/ml), appears to be a rapid, simple and sensitive screening method for detection and identification of fluconazole-susceptible and -highly resistant yeasts. However, additional methods should be used to determine whether positive growth in this medium is due to resistant strains (MIC > or = 64 micro g/ml) or to strains displaying dose-dependent susceptibility (MIC 16-32 micro g/ml). The usefulness of CHROMAgar Candida with fluconazole depends on the sample source and the species under study.
Linares
María José
MJ
Departamento de Microbiología. Facultad de Medicina. Hospital Universitario Reina Sofía. Córdoba. España. mi1lisim@uco.es
Charriel
Guadalupe
G
Solís
Francisco
F
Casal
Manuel
M
D000935:Antifungal Agents / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects* / Q000254:growth & development; D002863:Chromogenic Compounds / Q000032:analysis; D015169:Colony Count, Microbial; D003470:Culture Media; D025141:Drug Resistance, Fungal; D015725:Fluconazole / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests / Q000379:methods*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000254:growth & development; D013045:Species Specificity
D000935:Antifungal Agents; D002863:Chromogenic Compounds; D003470:Culture Media; D015725:Fluconazole