Clinical comparison of the Baxter MicroScan Yeast Identification Panel and the Vitek Yeast Biochemical Card

To determine the reliability of the Baxter MicroScan Yeast Identification Panel, processed by the Walkaway-96, and the Vitek Yeast Biochemical Card, 150 clinical yeast isolates (30 Candida albicans, 67 Candida species, not albicans, 26 Torulopsis glabrata, 13 Cryptococcus neoformans, 4 Saccharomyces cerevisiae, 6 Trichosporon beigelii, 3 Rhodotorula species, and 1 Geotrichum species) were tested on both systems. Results were compared with those obtained by the API 20C and the appearance of yeast cells on cornmeal Tween-80 agar. After inoculation of each system, results were available in 4 hours with MicroScan panels, 24-48 hours with Vitek cards, and 72 hours with the API 20C strips. On initial testing, 101 (67%) and 128 (85%) isolates, respectively, were correctly identified by MicroScan and Vitek. After repeat testing, the number of correctly identified isolates increased to 123 (82%) by MicroScan and to 142 (95%) by Vitek. Yeasts most commonly misidentified were Candida tropicalis, T glabrata, and Candida parapsilosis by MicroScan and C tropicalis and T glabrata by Vitek.