Rapid, presumptive identification of Torulopsis (Candida) glabrata and Candida krusei using Calcofluor white.

Background: Torulopsis glabrata and Candida krusei are both resistant to fluconazole; there-fore, rapid identification of these species may prevent unnecessary prescribing of this commonly-used antifungal agent.Methods: A total of 290 organisms were examined for their fluorescent appearance using epi-illumination with ultra-violet excitation and their fluorescence was compared.Results: Incorporating the fluorochrome calcofluor white at a concentration of 0.0025% in a peptone/glucose medium, and in sera for the germ tube test with Candida albicans, enhances the recognition of germ tubes. Several other species of yeast-like organisms were found to have characteristic fluorescent appearances in these and in aqueous solutions at this concentration.Conclusion: The use of these appearances as a rapid (in minutes) identification criteria for Torulopsis glabrata and Candida krusei is described. This may be of value as infections with these 2 species are often not treatable with fluconazole. [ABSTRACT FROM AUTHOR]