Comparative performance of Fungichrom I, Candifast and API 20C Aux systemsin the identification of clinically significant yeasts

To compare the performance of current chromogenic yeast identification meth ods, three commercial systems (A-PI 20C Aux, Fungichrom I and Candifast) we re evaluated in parallel, along with conventional tests to identify yeasts commonly isolated in this clinical microbiology laboratory. In all, 116 cli nical isolates, (68 Candida albicans, 12 C. parapsilosis, 12 C glabrata and 24 other yeasts) were tested. Germ-tube production, microscopical morpholo gy and other conventional methods were used as standards to definitively id entify yeast isolates. The percentage of isolates identified correctly vari ed between 82.7% and 95.6%. Overall, the performance obtained with Fungichr om I was highest with 95.6% identification (111 of 116 isolates). The perfo rmance of API 20C Aux was higher with 87% (101 of 116 isolates) than that o f Candifast with 82.7% (96 of 116). The Fungichrom I method was found to be rapid, as 90% of strains were identified after incubation for 24 h at 30 d egreesC. Both of the chromogenic yeast identification systems provided a si mple, accurate alternative to API 20C Aux and conventional assimilation met hods for the rapid identification of most commonly encountered isolates of Candida spp. Fungichrom seemed to be the most appropriate system for use in a clinical microbiology laboratory, due to its good performance with regar d to sensitivity, ease of use and reading, rapidity and the cost per test.