Aspergillus Section Terrei and Antifungals: From Broth to Agar-Based Susceptibility Testing Methods

TY - JOUR

T1 - Aspergillus Section Terrei and Antifungals

T2 - From Broth to Agar-Based Susceptibility Testing Methods

AU - Vahedi-Shahandashti, Roya

AU - Hahn, Lisa

AU - Houbraken, Jos

AU - Lass-Flörl, Cornelia

N1 - Funding Information: The authors would thank Sonja Jähnig for technical assistance. Open Access Funding by the Austrian Science Fund (FWF). Funding Information: This research was funded by FWF Austrian Science Fund, grant number W1253-B24. Publisher Copyright: © 2023 by the authors.

PY - 2023/3

Y1 - 2023/3

N2 - Providing timely antifungal treatment to patients suffering from life-threatening invasive fungal infections (IFIs) is essential. Due to the changing epidemiology and the emergence of antifungal resistance in Aspergillus, the most commonly responsible mold of IFIs, antifungal susceptibility testing (AFST) has become increasingly important to guide clinical decisions. This study assessed the essential agreement (EA) between broth microdilution methods (the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST)) and the Etest of amphotericin B (AmB), liposomal amphotericin B (L-AmB), and isavuconazole (ISA) against 112 Aspergillus section Terrei. An EA within ±2 dilutions of ≥90% between the two methods was considered acceptable. Excellent EA was found between EUCAST and CLSI of AmB and ISA (98.2% and 95.5%, respectively). The correlation of Etest results and EUCAST/CLSI was not acceptable (<90%) for any tested antifungal; however, Etest and CLSI for AmB (79.6%) and ISA (77.6%) showed a higher EA than Etest and EUCAST for AmB (49.5%) and ISA (46.4%). It was concluded that the Etest method requires its own clinical breakpoints (CBPs) and epidemiological cutoff values (ECVs), and interpreting Etest results using EUCAST and CLSI-adapted CBPs and ECVs could result in misinterpretation as Etest shows lower minimum inhibitory concentrations (MICs).

AB - Providing timely antifungal treatment to patients suffering from life-threatening invasive fungal infections (IFIs) is essential. Due to the changing epidemiology and the emergence of antifungal resistance in Aspergillus, the most commonly responsible mold of IFIs, antifungal susceptibility testing (AFST) has become increasingly important to guide clinical decisions. This study assessed the essential agreement (EA) between broth microdilution methods (the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST)) and the Etest of amphotericin B (AmB), liposomal amphotericin B (L-AmB), and isavuconazole (ISA) against 112 Aspergillus section Terrei. An EA within ±2 dilutions of ≥90% between the two methods was considered acceptable. Excellent EA was found between EUCAST and CLSI of AmB and ISA (98.2% and 95.5%, respectively). The correlation of Etest results and EUCAST/CLSI was not acceptable (<90%) for any tested antifungal; however, Etest and CLSI for AmB (79.6%) and ISA (77.6%) showed a higher EA than Etest and EUCAST for AmB (49.5%) and ISA (46.4%). It was concluded that the Etest method requires its own clinical breakpoints (CBPs) and epidemiological cutoff values (ECVs), and interpreting Etest results using EUCAST and CLSI-adapted CBPs and ECVs could result in misinterpretation as Etest shows lower minimum inhibitory concentrations (MICs).

KW - amphotericin B

KW - antifungal resistance

KW - antifungal susceptibility testing

KW - Aspergillus terreus

KW - clinical breakpoints

KW - CLSI

KW - epidemiological cutoff values

KW - EUCAST

KW - isavuconazole

UR - http://www.scopus.com/inward/record.url?scp=85160448153&partnerID=8YFLogxK

U2 - 10.3390/jof9030306

DO - 10.3390/jof9030306

M3 - Article

AN - SCOPUS:85160448153

SN - 2309-608X

VL - 9

JO - Journal of Fungi

JF - Journal of Fungi

IS - 3

M1 - 306

ER -