Commercial Methods for Antifungal Susceptibility Testing of Saprophytic Molds: Can They Be Used to Detect Resistance?

oleh: Paschalis Paranos, Ana Espinel-Ingroff, Joseph Meletiadis

Format: Article
Diterbitkan: MDPI AG 2024-03-01

Deskripsi

Commercial tests are often employed in clinical microbiology laboratories for antifungal susceptibility testing of filamentous fungi. Method-dependent epidemiological cutoff values (ECVs) have been defined in order to detect non-wild-type (NWT) isolates harboring resistance mechanisms. We reviewed the literature in order to find studies where commercial methods were used to evaluate for in vitro susceptibility of filamentous fungi and assess their ability to detect NWT isolates according to the available ECVs. Data were found for the gradient concentration strips Etest and MIC Test Strips (MTS), broth microdilution Sensititre YeastOne (SYO), Micronaut-AM and the agar dilution VIPcheck assays. Applying itraconazole, voriconazole and posaconazole Etest ECVs for <i>A. fumigatus</i>, Etest was able to detect 90.3% (84/93), 61.2% (90/147) and 86% (31/36) of isolates with known <i>cyp51A</i> mutations, respectively. Moreover, Etest also was able to detect 3/3 <i>fks</i> mutants using caspofungin ECVs and 2/3 micafungin mutant isolates. Applying the voriconazole and posaconazole SYO ECVs, 57.7% (67/116) and 100% (47/47) of mutants with known <i>cyp51A</i> substitutions were classified as NWT, respectively. VIPcheck detected 90.3% (159/176), 80.1% (141/176) and 66% (141/176)of mutants via itraconazole, voriconazole and posaconazole, respectively, whereas Micronaut-AM detected 88% (22/25). In conclusion, Etest posaconazole and itraconazole, as well as micafungin and caspofungin ECVs, detected <i>A. fumigatus</i> mutants. On the other hand, while the posaconazole SYO ECV was able to detect <i>cyp51A</i> mutants, similar data were not observed with the SYO voriconazole ECV.