Multicentre validation of a modified EUCAST MIC testing method and development of associated epidemiologic cut-off (ECOFF) values for rezafungin
Research output: Contribution to journal › Journal article › Research › peer-review
Standard
Multicentre validation of a modified EUCAST MIC testing method and development of associated epidemiologic cut-off (ECOFF) values for rezafungin. / Arendrup, Maiken Cavling; Arikan-Akdagli, Sevtap; Castanheira, Mariana; Guinea, Jesus; Locke, Jeffrey B.; Meletiadis, Joseph; Zaragoza, Oscar.
In: The Journal of antimicrobial chemotherapy, Vol. 78, No. 1, 2022, p. 185-195.Research output: Contribution to journal › Journal article › Research › peer-review
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Multicentre validation of a modified EUCAST MIC testing method and development of associated epidemiologic cut-off (ECOFF) values for rezafungin
AU - Arendrup, Maiken Cavling
AU - Arikan-Akdagli, Sevtap
AU - Castanheira, Mariana
AU - Guinea, Jesus
AU - Locke, Jeffrey B.
AU - Meletiadis, Joseph
AU - Zaragoza, Oscar
N1 - Publisher Copyright: © The Author(s) 2022. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
PY - 2022
Y1 - 2022
N2 - OBJECTIVES: Rezafungin EUCAST MIC testing has been associated with notable inter-laboratory variation, which prevented ECOFF setting for C. albicans. We assessed in vitro susceptibility and reproducibility for a modified EUCAST methodology and established associated wild-type upper limits (WT-ULs). METHODS: MICs against 150 clinical Candida isolates (six species), molecularly characterized fks mutants (n = 13), and QC strains (n = 6) were determined at six laboratories according to E.Def 7.3 but using Tween 20 supplemented medium. WT-ULs were determined using the derivatization method, the ECOFFinder programme and visual inspection. Consensus WT-ULs were determined. RESULTS: The laboratory- and species-specific MIC distributions were Gaussian with >99.5% MICs within four 2-fold dilutions except for C. parapsilosis (92.8%). The following consensus WT-UL were determined: C. albicans 0.008 mg/L; C. dubliniensis and C. glabrata 0.016 mg/L; C. krusei and C. tropicalis 0.03 mg/L; and C. parapsilosis 4 mg/L. Adopting these WT-UL, six clinical isolates were non-wild-type, five of which harboured Fks alterations. For 11/13 mutants, all 670 MICs were categorized as non-wild-type whereas MICs for C. glabrata Fks2 D666Y and C. tropicalis Fks1 R656R/G overlapped with the corresponding wild-type distributions. Repeat testing of six reference strains yielded 98.3%-100% of MICs within three 2-fold dilutions except for C. albicans CNM-CL-F8555 (96%) and C. parapsilosis ATCC 22019 (93.3%). CONCLUSIONS: The modified EUCAST method significantly improved inter-laboratory variation, identified wild-type populations and allowed perfect separation of wild-type and fks mutants except for two isolates harbouring weak mutations. These consensus WT-UL have been accepted as ECOFFs and will be used for rezafungin breakpoint setting.
AB - OBJECTIVES: Rezafungin EUCAST MIC testing has been associated with notable inter-laboratory variation, which prevented ECOFF setting for C. albicans. We assessed in vitro susceptibility and reproducibility for a modified EUCAST methodology and established associated wild-type upper limits (WT-ULs). METHODS: MICs against 150 clinical Candida isolates (six species), molecularly characterized fks mutants (n = 13), and QC strains (n = 6) were determined at six laboratories according to E.Def 7.3 but using Tween 20 supplemented medium. WT-ULs were determined using the derivatization method, the ECOFFinder programme and visual inspection. Consensus WT-ULs were determined. RESULTS: The laboratory- and species-specific MIC distributions were Gaussian with >99.5% MICs within four 2-fold dilutions except for C. parapsilosis (92.8%). The following consensus WT-UL were determined: C. albicans 0.008 mg/L; C. dubliniensis and C. glabrata 0.016 mg/L; C. krusei and C. tropicalis 0.03 mg/L; and C. parapsilosis 4 mg/L. Adopting these WT-UL, six clinical isolates were non-wild-type, five of which harboured Fks alterations. For 11/13 mutants, all 670 MICs were categorized as non-wild-type whereas MICs for C. glabrata Fks2 D666Y and C. tropicalis Fks1 R656R/G overlapped with the corresponding wild-type distributions. Repeat testing of six reference strains yielded 98.3%-100% of MICs within three 2-fold dilutions except for C. albicans CNM-CL-F8555 (96%) and C. parapsilosis ATCC 22019 (93.3%). CONCLUSIONS: The modified EUCAST method significantly improved inter-laboratory variation, identified wild-type populations and allowed perfect separation of wild-type and fks mutants except for two isolates harbouring weak mutations. These consensus WT-UL have been accepted as ECOFFs and will be used for rezafungin breakpoint setting.
U2 - 10.1093/jac/dkac373
DO - 10.1093/jac/dkac373
M3 - Journal article
C2 - 36329639
AN - SCOPUS:85144591910
VL - 78
SP - 185
EP - 195
JO - Journal of Antimicrobial Chemotherapy
JF - Journal of Antimicrobial Chemotherapy
SN - 0305-7453
IS - 1
ER -
ID: 332601567