ABILITY OF RAPID YEAST PLUS SYSTEM TO IDENTIFY 304 CLINICALLY SIGNIFICANT YEASTS WITHIN 5 HOURS

The RapID Yeast Plus System (Innovative Diagnostic Systems, Norcross, Ga.) is a qualitative micromethod that uses conventional and chromogen ic substrates for the identification of medically important yeasts. Th e ability of the RapID Yeast Plus system to accurately identify 304 cl inical yeast isolates within 5 h was evaluated. The RapID Yeast Plus m ethod correctly identified 286 (94.1%) of strains to the species level without the need for additional tests. A further 12 strains (3.9%) we re classified as correct to the genus level or to a low-probability id entification with two or more possibilities. In these latter cases, ad ditional tests were required to delineate the correct identification. Organisms in the latter group comprised Candida parapsilosis (n = 1), Candida tropicalis (n = 1), Candida ciferrii (n = 1), Candida guillier mondii (n = 2), Candida humicola (n = 1), Candida kefyr (n = 1), Crypt ococcus neoformans (n = 1), and Rhodotorula rubra (n = 4). Six strains (2.0%) were misidentified or did not yield codes in the manufacturer' s database, These included one Candida utilis (identified as Candida f amata/Candida guilliermondii), one Trichosporon beigelii (identified a s Cryptococcus neoformans), one Candida diddensiae (identified as Cand ida albicans), one Candida membranaefaciens (identified as Candida par apsilosis), one Candida norvegensis (identified as Candida zeylanoides ), and one Candida catenulata (no code) isolate; the last four strains are not included in the firm's current database. The RapID Yeast Plus system yielded excellent results and may be recommended for use in th e routine laboratory for accurate same-day identification of clinicall y significant yeasts.