COMPARISON OF THE RAPID YEAST PLUS PANEL WITH THE API20C YEAST SYSTEMFOR IDENTIFICATION OF CLINICALLY SIGNIFICANT ISOLATES OF CANDIDA SPECIES

The RapID Yeast Plus system (Innovative Diagnostic Systems, Norcross, Ga.) is a qualitative micromethod employing conventional tests and sin gle-substrate chromogenic tests and having a 4-h incubation period. Th is system was compared with the API20C (bioMerieux Vitek Hazelwood, Mo .) system, a 24- to 72-h carbohydrate assimilation method, One hundred thirty-three clinical yeast isolates, including 57 of Candida albican s, 26 of Candida tropicalis, 23 of Candida glabrata, and 27 of other y easts, were tested by both methods. When discrepancies occurred, isola tes were further tested by the Automated Yeast Biochemical Card (bioMe rieux Vitek). Germ tube production and microscopic morphology were use d as needed to definitively identify yeast isolates. The RapID Yeast P lus system correctly identified 125 yeast isolates, with an overall ac curacy of 94% (125 of 133). Excellent correlation was found in the rec ognition of the three yeasts most commonly isolated from human sources . The test was 99% (105 of 106 isolates) accurate with C. albicans, C. tropicalis, and C. glabrata. The RapID Yeast Plus system compares fav orably with the API20C system and provides a simple, accurate alternat ive to conventional assimilation methods for the rapid identification of the most commonly encountered isolates of Candida species.