M-1543. Performance of the VITEK2 Yeats® for Susceptibility Testing of Antifungal Agents against Candida spp. and Cryptococcus neoformans
Session: Poster Session: Antifungal Susceptibility
Sunday, October 26, 2008: 12:00 AM
Room: Hall C
Background : VITEK2 yeast (bioMerieux) is designed for yeast identification and susceptibility testing of antifungal agents. We compared susceptibility testing results obtained by VITEK2 Yeast to those obtained using reference methods. This has never been done for Cryptococcus neoformans. Methods : Were included in the analysis: 115 isolates of Candida spp from blood cultures (65 C. albicans, 22 C. glabrata, 10 C. tropicalis, 10 others) and 10 isolates of C. neoformans. The isolates were tested for amphotericin B (AMB), 5-flucytosine (5FC), fluconazole (FCZ) and voriconazole (VRZ) susceptibility using VITEK2, Etest and the EUCAST reference method. Essential Agreement (EA) was defined as MIC endpoints within +/- 2 dilutions. Categorical agreement (CA) was calculated based on previously published breakpoints. Results: Excellent EA between VITEK2 and 24h-EUCAST was observed for AMB (97%), 5FC (98%), FCZ (89%) and VRZ (98%). With regard to species, the EA was > 95% for all species-drug combinations but C. glabrata (EA 70% for FCZ). CA between VITEK 2 and EUCAST ranged from 91% for FCZ to 98% for 5FC for Candida spp. For C. neoformans, EA ranged from 70% for FCZ to 100% for 5FC and CA ranged from 90% for 5FC to 100% for FCZ. Similar results were observed between VITEK2 and Etest with CA ranging from 93% for FCZ to 99% for VRZ. VITEK2 endpoints could be determined after 15.07 +/- 1.73 h of incubation for Candida spp. and 19.70 +/- 1.42 h for C. neoformans, whereas endpoints with Etest and reference method were 24 and 48 hours.
Conclusions : These results indicate that VITEK2 can accurately detect high-level resistance among C. neoformans and C. albicans isolates with excellent quantitative and qualitative agreements with the reference EUCAST method. VITEK2 can also provide faster results than Etest.
Catherine Cordonnier1, Ccile Farrugia2, Celine Corbel3, Emmanuelle Cambau, MD, PhD4, Françoise Foulet5, Françoise Botterel6, Stphane Bretagne, MD, PhD5 and  F. Botterel, None., (1)Hematology Department, Hpital Henri Mondor, APHP, (2)Mycology Department, Hpital Henri Mondor, APHP and Universit Paris 12, (3)Universite Paris12; AP-HP, Henri Mondor Hospital, (4)Universite Paris12; AP-HP, Henri Mondor Hospital, Creteil, France, (5)APHP, (6)APHP, Creteil, France

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