Comparison of the Micronaut-AM System and the EUCAST Broth Microdilution Reference Method for MIC Determination of Four Antifungals against Aspergillus fumigatus

The Antifungal Susceptibility Testing method of the European Committee on Antimicrobial (EUCAST-AFST) is a reference technique for determination Minimum Inhibitory Concentration (MIC) antifungals Aspergillus fumigatus. However, it time-consuming and requires expertise. Micronaut-AM (M-AM) fast, simple, time-saving, ready-to-use new colorimetric using an indicator (resazurin) to facilitate visual reading. aim this retrospective study was evaluate performance M-AM system compare with EUCAST broth microdilution determine susceptibility 77 A. fumigatus clinical strains amphotericin B, itraconazole, voriconazole, posaconazole. Overall, essential agreements within ±2 dilutions were 100%, 62%, 58%, 30% categorical 97%, 91%, 87% posaconazole, respectively. No discrepancy found but several discordances observed azole antifungals. only 2 16 azole-resistant confirmed by cyp51A sequencing would have been misclassified M-AM. use probably suitable MICs further evaluations are needed confirm its usefulness azoles