A Multi-Site Evaluation of Isavuconazole on the Sensititre YeastOne Test Plate with the Frozen Reference CLSI M27-A3 and ISO 16256 Micro Broth Dilution Methods for Antifungal Susceptibility Testing A Multi-Site Evaluation of Isavuconazole on the Sensititr

N. M. Holliday1, C. C. Knapp1, S. B. Killian1, D. N. Zollos1, E. Scopes2, M. A. Ghannoum3, R. N. Jones4, J. M. Streit4, M. Castanheira4, R. R. Dietrich4, S. A. Messer4, K. Lagrou5, S. Patteet5

Author address: 

1Thermo Fisher Scientific, Oakwood Village, OH, 2Thermo Fisher Scientific, Basingstoke, United Kingdom, 3Case Western Reserve Univ., Cleveland, OH, 4JMI Lab., North Liberty, IA, 5UZ Leuven, Leuven, Belgium


Background: Isavuconazole (Astellas Pharma US, Inc., Northbrook, IL) is a triazole antifungal that is currently approved for use in the treatment of invasive mucormycosis and aspergillosis. A multi-site evaluation was undertaken to determine the performance of the Thermo Scientific™ Sensititre® YeastOne® susceptibility system (Thermo Fisher Scientific, Cleveland, OH) with Isavuconazole (ISA) compared to the CLSI M27 and ISO16256 (2012)(E) Broth Microdilution Methods (BMD).Materials and Methods: 400 clinical (100 per site) and 100 challenge strains along with 10 reproducibility isolates of Candida spp. were tested at 4 sites comparing the performance of ISA on the Sensititre YeastOne plate with CLSI and ISO BMD. The range tested for ISA was 0.004-8ug/ml. CLSI quality control (QC) organisms were tested daily and were within the CLSI expected QC ranges. Results: Clinical isolate comparisons of the Sensititre YeastOne plate to the CLSI and ISO BMD resulted in 99% and 92% essential agreement (EA) +/- 2 log2 dilutions. Challenge isolates resulted in 99% and 89% EA +/- 2 log2 dilutions. YeastOne modal reproducibility MICs +/- 2 fold dilutions between sites for ISA resulted in 98.6% agreement at 24 hours. Conclusions: This evaluation indicates that the Sensititre YeastOne plate with ISA is equivalent to the CLSI and ISO BMD and is a potential method for susceptibility testing of ISA.

abstract No: 


Full conference title: 

ASM Microbe 2016
    • ASM microbe 1st (2016)