Evaluation of the VITEK 2 system to test the susceptibility of Candida spp., Trichosporon asahii and Cryptococcus neoformans to amphotericin B, flucytosine, fluconazole and voriconazole: a comparison with the M27-A3 reference method.
We compared the susceptibilities of 302 isolates (209 Candida spp., 89 Cryptococcus neoformans and four Trichosporon asahii) against amphotericin B (AMB), flucytosine (5FC), fluconazole (FLC) and voriconazole (VRC) obtained with an automated commercial system (VITEK 2, bioMérieux, Spain) and the Clinical and Laboratory Standards Institute (CLSI M27-A3) reference broth microdilution method (BMD). Reference BMD MIC endpoints were determined visually after 24-72 h of incubation, depending on the species, and VITEK 2 system MIC endpoints were determined spectrophotometrically by automated components of this equipment. For Candida spp. and T. asahii, the overall MIC agreement between of the results of the VITEK 2 system and the 24/48-h BMD was: 34/62% for AMB; 96.3% at 24/48-h for 5FC; 87.8/87.3% for FLC and 95.3/92% for VRC, respectively. The overall categorical agreement between both methods was: 98.5/97.6% for AMB at 24/48-h; 95.3% for 5FC at 24/48-h; 85.4/84.4% at 24/48-h for FLC; and 97.6/92.95% at 24/48-h for VRC. For C. neoformans, essential agreement was good for FLC (91%) and 5FC (84.2%) but not so good for AMB (69%). Excellent categorical agreement was obtained for all antifungal agents tested except for 5FC (69.7%). This new system could play an important role in the clinical laboratory, but more studies are necessary to verify its ability to identify resistant isolates.
Cejudo
M A Trinidad González
MA
Servicio de Microbiología y Parasitología, Hospital de Valme, Carretera de Cádiz s/n, Seville, Spain.
Gallego
Auxiliadora González
AG
Lacasa
Emilia Cantón
EC
Aller
Ana Isabel
AI
Romero
Ana
A
García
Javier Pemán
JP
Andrés
Guillermo Quindós
GQ
Martín-Mazuelos
Estrella
E
D000935:Antifungal Agents / Q000494:pharmacology*; D001331:Automation / Q000379:methods; D002175:Candida / Q000187:drug effects* / Q000302:isolation & purification; D003455:Cryptococcus neoformans / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D009172:Mycology / Q000379:methods*; D013030:Spain; D014250:Trichosporon / Q000187:drug effects* / Q000302:isolation & purification
D000935:Antifungal Agents