Detection of fluconazole-resistant isolates of Candida glabrata by using an agar screen assay

The ability of a fluconazole-containing agar screen assay to accurately detect isolates of Candida glabrata resistant to the azole antifungal agent fluconazole was evaluated on a collection of 100 clinical isolates of this organism. Results were correlated with the MIC of fluconazole for these isolates and compared with the results of a previously published disk diffusion-based fluconazole resistance screening test. Agar screen assay results were in categorical agreement with MIC-based determinations for 97% (97/100) of the isolates tested. This correlation was higher than that obtained with the disk diffusion technique, which categorized only 87% (87/100) of isolates correctly, and suggests that the agar screening approach can effectively expedite fluconazole susceptibility testing of C. glabrata isolates.