Evaluation of the VITEK 2 system for rapid identification of yeasts and yeast-like organisms

The new VITEK 2 system is a fully automated system dedicated to the identif ication and susceptibility testing of microorganisms. In conjunction with t he VITEK ID-YST card the VITEK 2 system allows the identification of clinic ally important yeasts and yeast-like organisms in 15 h due to a sensitive f luorescence-based technology. The ID-YST card consists of 47 biochemical re actions. The database comprises 51 taxa, including newly described species. In this study we evaluated the reliability of the VITEK ID-YST card for th e identification of yeasts and yeast-like organisms encountered in a clinic al microbiology laboratory. A total of 241 strains representing 21 species were studied. The strains were isolated from clinical samples within a peri od of 60 days prior to the identification, The tests were performed using 2 4-h to 55-h subcultures on Sabouraud-gentamicin-chloramphenicol agar, Each strain was tested in parallel using the ID 32C strip as a comparison method combined with microscopic morphology and an agglutination test for C. krus ei, Overall, 222 strains (92.1%) were unequivocally identified including 11 isolates (4.6%) identified with low discrimination resolved by simple addi tional tests. Ten strains (4.1%) for which results were given with low disc rimination could not be unequivocally identified with supplemental tests, 4 strains (1.7%) were misidentified and 5 strains (2.1%) could not be identi fied. In conclusion, we found that the VITEK 2 system is a rapid and accura te method for the identification of medically important yeasts and yeast-li ke organisms.