Evaluation of the API 20C for identification of yeasts

The API 20C reactions were compared with the results of conventional methods for identifying yeasts using 45 strains. There was a 98% (44/45) correlation between the two methods in the identification of the yeasts. Individual fermentation tests ranged from 89 to 100% correlation, with an average agreement of 96.7%. The assimilation tests ranged from 85 to 100% correlation, with an overall agreement of 97.3%. The two methods had 91% agreement for cycloheximide resistance. The results of this limited study indicate that the API 20C may prove to be an acceptable substitute for conventional carbohydrate fermentation and assimilation tests.