Comparison of Vitek identification and antifungal susceptibility testing methods to DNA sequencing and Sensititre YeastOne antifungal testing.
The colorimetric Vitek 2 YST card and the yeast susceptibility test (AST-YS01) were evaluated for their identification efficacy and their use in assessing the in vitro susceptibility of Candida spp. to fluconazole, voriconazole and amphotericin B. Ninety-one percent or 62 of 68 Candida isolates from blood specimens were correctly identified, as compared to determinations of the ITS2 fragment length. The overall essential agreements between Vitek 2 and the Sensititre YeastOne (SYO) colorimetric method were 78.4%, 84.6% and 90.8%, for fluconazole, voriconazole and amphotericin B, respectively. The overall categorical agreements between Vitek 2 and SYO for fluconazole and voriconazole were 76.9% and 96.9%, respectively. The poorest agreement between Vitek 2 and SYO was seen with C. glabrata (n = 27), particularly for fluconazole. The MIC values of 2 C. glabrata strains (3%) could not be determined with the Vitek 2 due to an insufficient growth in the control well. For other Candida species (n = 38) Vitek 2 and SYO showed acceptable agreements.
Vijgen
Sara
S
Clinical Laboratory, Jessa Hospital, Hasselt, Belgium. sara.vijgen@jessazh.be
Nys
Sita
S
Naesens
Reinout
R
Magerman
Koen
K
Boel
An
A
Cartuyvels
Reinoud
R
D000666:Amphotericin B / Q000494:pharmacology; D002175:Candida / Q000145:classification* / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D004271:DNA, Fungal / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D015725:Fluconazole / Q000494:pharmacology; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D016533:Mycological Typing Techniques / Q000379:methods; D011743:Pyrimidines / Q000494:pharmacology; D014230:Triazoles / Q000494:pharmacology; D065819:Voriconazole
D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer; D011743:Pyrimidines; D014230:Triazoles; D000666:Amphotericin B; D015725:Fluconazole; D065819:Voriconazole