Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2016

Comparative Evaluation of MICRONAUT-AM EUCAST AFST2-Test Plate and Sensititre® YeastOne® Plate (CLSI) for Susceptibility Testing of Candida Species (#201)

Vishal Ahuja 1 , Menuk Jayawardena 1 , Sharon C.-A Chen 1 , Catriona L. Halliday 1
  1. Clinical Mycology Reference Laboratory, Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR - Pathology West, Westmead Hospital, Westmead, NSW, Australia

Clinical laboratories require a simple and reliable method to determine the minimal inhibitory concentration (MIC) or minimal effective concentration (MEC) of antifungal agents. Although the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) have standardised broth microdilution methods for susceptibility testing of yeasts, these are time-consuming. Here we evaluated the performance of the MICRONAUT-AM EUCAST AFST2-Test Plate (Merlin Diagnostika, Germany) a new EUCAST-based colorimetric broth microdilution system and compared it with the CLSI-based Sensititre® YeastOne® YO10 system (TREK Diagnostics Systems). MIC/MECs to six antifungal drugs (amphotericin B, fluconazole, posaconazole, voriconazole, micafungin and andidulafungin) were determined by both methods, according to the manufacturers’ protocols for a collection of clinically relevant Candida species (including C. albicans, C. glabrata, C. parapsilosis, C. krusei [Pichia kudriavzevii], C. tropicalis, and C. dubliniensis). Interpretative breakpoints were applied according to EUCAST breakpoint table version 8 and CLSI M27-S4 document. Results thus far show the overall essential agreement (within two drug dilutions) between the two methods are 81.4% (posaconazole), 86.4% (amphotericin B), 89.8% (voriconazole), 93.2% (fluconazole) and 98.3% (micafungin and anidulafungin). Where applicable, the overall categorical agreement in interpretation of the MICs ranged from 84.3% (micafungin) to 94.7% (fluconazole). The results of this small study indicate the two commercial methods produce comparable results for testing antifungal agents against common Candida species and further study with larger numbers and additional species is warranted.