Evaluation of a commercial multitest system for identification of yeasts

A new commercial yeast identification system, the Randolph Multitest Mycology Plate, was evaluated. This system is based on the assimilation of carbohydrates, growth on birdseed agar, resistance to cycloheximide, hydrolysis of urea, and reduction of nitrate. The 184 clinical isolates used in the evaluation included 20 species of the genera Candida, Cryptococcus, Saccharomyces, Torulopsis, Trichosporon, Rhodotorula, and Geotrichum. Agreement with the standard Wickerham carbohydrate assimilation and other conventional biochemical results was found in 84 percent of the tests, and 91 percent of the yeasts were correctly identified with the aid of microscopy, cultural characteristics, and germ-tube formation. Identification of the tested strains was achieved within 96 hours.