TY - JOUR
T1 - Candida parapsilosis isolates carrying mutations outside FKS1 hotspot regions confer high echinocandin tolerance and facilitate the development of echinocandin resistance
AU - Daneshnia, Farnaz
AU - Arastehfar, Amir
AU - Lombardi, Lisa
AU - Binder, Ulrike
AU - Scheler, Jakob
AU - Vahedi Shahandashti, Roya
AU - Hagen, Ferry
AU - Lass-Flörl, Cornelia
AU - Mansour, Michael K
AU - Butler, Geraldine
AU - Perlin, David S
N1 - Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.
PY - 2023/7
Y1 - 2023/7
N2 - Candida parapsilosis is a significant cause of candidemia worldwide. Echinocandin-resistant (ECR) and echinocandin-tolerant (ECT) C. parapsilosis isolates have been reported in various countries but are rare. Resistance and tolerance are predominantly caused by mutations related to the hotspot (HS) regions of the FKS1 gene. A relatively high proportion of clinical C. parapsilosis isolates carrying mutations outside the HS regions has been noted in some studies, but an association with echinocandin (EC) resistance or tolerance was not explored. Herein, CRISPR-Cas9 was used and the association between amino acid substitution in FKS1 outside HS 1/2 (V595I, S745L, M1328I, F1386S, and A1422G) with EC susceptibility profile was delineated. None of the mutations conferred EC resistance, but they resulted in a significantly higher level of EC tolerance than the parental isolate, ATCC 22019. When incubated on agar plates containing ECs, specifically caspofungin and micafungin, ECR colonies were exclusively observed among ECT isolates, particularly mutants carrying V595I, S745L, and F1386S. Additionally, mutants had significantly better growth rates in yeast extract peptone dextrose (YPD) and YPD containing agents inducing membrane and oxidative stresses. The mutants had a trivial fitness cost in the Galleria mellonella model relative to ATCC 22019. Collectively, this study supports epidemiological studies to catalog mutations occurring outside the HS regions of FKS1, even if they do not confer EC resistance. These mutations are important as they potentially confer a higher level of EC tolerance and a higher propensity to develop EC resistance, therefore unveiling a novel mechanism of EC tolerance in C. parapsilosis. The identification of EC tolerance in C. parapsilosis may have direct clinical benefit in patient management.
AB - Candida parapsilosis is a significant cause of candidemia worldwide. Echinocandin-resistant (ECR) and echinocandin-tolerant (ECT) C. parapsilosis isolates have been reported in various countries but are rare. Resistance and tolerance are predominantly caused by mutations related to the hotspot (HS) regions of the FKS1 gene. A relatively high proportion of clinical C. parapsilosis isolates carrying mutations outside the HS regions has been noted in some studies, but an association with echinocandin (EC) resistance or tolerance was not explored. Herein, CRISPR-Cas9 was used and the association between amino acid substitution in FKS1 outside HS 1/2 (V595I, S745L, M1328I, F1386S, and A1422G) with EC susceptibility profile was delineated. None of the mutations conferred EC resistance, but they resulted in a significantly higher level of EC tolerance than the parental isolate, ATCC 22019. When incubated on agar plates containing ECs, specifically caspofungin and micafungin, ECR colonies were exclusively observed among ECT isolates, particularly mutants carrying V595I, S745L, and F1386S. Additionally, mutants had significantly better growth rates in yeast extract peptone dextrose (YPD) and YPD containing agents inducing membrane and oxidative stresses. The mutants had a trivial fitness cost in the Galleria mellonella model relative to ATCC 22019. Collectively, this study supports epidemiological studies to catalog mutations occurring outside the HS regions of FKS1, even if they do not confer EC resistance. These mutations are important as they potentially confer a higher level of EC tolerance and a higher propensity to develop EC resistance, therefore unveiling a novel mechanism of EC tolerance in C. parapsilosis. The identification of EC tolerance in C. parapsilosis may have direct clinical benefit in patient management.
KW - Humans
KW - Antifungal Agents/pharmacology
KW - Candida parapsilosis/genetics
KW - Candida/genetics
KW - Fungal Proteins/genetics
KW - Drug Resistance, Fungal/genetics
KW - Microbial Sensitivity Tests
KW - Echinocandins/pharmacology
KW - Mutation
U2 - 10.1016/j.ijantimicag.2023.106831
DO - 10.1016/j.ijantimicag.2023.106831
M3 - Article
C2 - 37121442
SN - 0924-8579
VL - 62
SP - 106831
JO - International Journal of Antimicrobial Agents
JF - International Journal of Antimicrobial Agents
IS - 1
ER -