Evaluation of the Vitek 2 system for antifungal susceptibility testing of Candida auris using a representative international panel of clinical isolates: overestimation of amphotericin B resistance and underestimation of fluconazole resistance.

Autor:	Siopi M; Clinical Microbiology Laboratory, 'Attikon' University General Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.; Molecular Microbiology and Immunology Laboratory, Department of Biomedical Sciences, University of West Attica, Athens, Greece., Pachoulis I; Clinical Microbiology Laboratory, 'Attikon' University General Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.; Molecular Microbiology and Immunology Laboratory, Department of Biomedical Sciences, University of West Attica, Athens, Greece., Leventaki S; Clinical Microbiology Laboratory, 'Attikon' University General Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.; Molecular Microbiology and Immunology Laboratory, Department of Biomedical Sciences, University of West Attica, Athens, Greece., Spruijtenburg B; Canisius-Wilhelmina Hospital (CWZ)/Dicoon, Nijmegen, the Netherlands.; Radboudumc-CWZ Center of Expertise for Mycology, Nijmegen, the Netherlands., Meis JF; Radboudumc-CWZ Center of Expertise for Mycology, Nijmegen, the Netherlands.; Institute of Translational Research, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Excellence Center for Medical Mycology (ECMM), University of Cologne, Cologne, Germany., Pournaras S; Clinical Microbiology Laboratory, 'Attikon' University General Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece., Vrioni G; Department of Microbiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece., Tsakris A; Department of Microbiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece., Meletiadis J; Clinical Microbiology Laboratory, 'Attikon' University General Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
Jazyk:	angličtina
Zdroj:	Journal of clinical microbiology [J Clin Microbiol] 2024 Apr 10; Vol. 62 (4), pp. e0152823. Date of Electronic Publication: 2024 Mar 19.
DOI:	10.1128/jcm.01528-23
Abstrakt:	Although the Vitek 2 system is broadly used for antifungal susceptibility testing of Candida spp., its performance against Candida auris has been assessed using limited number of isolates recovered from restricted geographic areas. We therefore compared Vitek 2 system with the reference Clinical and Laboratory Standards Institute (CLSI) broth microdilution method using an international collection of 100 C . auris isolates belonging to different clades. The agreement ±1 twofold dilution between the two methods and the categorical agreement (CA) based on the Centers for Disease Control and Prevention's (CDC's) tentative resistance breakpoints and Vitek 2-specific wild-type upper limit values (WT-ULVs) were determined. The CLSI-Vitek 2 agreement was poor for 5-flucytosine (0%), fluconazole (16%), and amphotericin B (29%), and moderate for voriconazole (61%), micafungin (67%), and caspofungin (81%). Significant interpretation errors were recorded using the CDC breakpoints for amphotericin B (31% CA, 69% major errors; MaEs) and fluconazole (69% CA, 31% very major errors; VmEs), but not for echinocandins (99% CA, 1% MaEs for both micafungin and caspofungin) for which the Vitek 2 allowed correct categorization of echinocandin-resistant FKS1 mutant isolates. Discrepancies were reduced when the Vitek 2 WT-ULV of 16 mg/L for amphotericin B (98% CA, 2% MaEs) and of 4 mg/L for fluconazole (96% CA, 1% MaEs, 3% VmEs) were used. In conclusion, the Vitek 2 system performed well for echinocandin susceptibility testing of C .auris . Resistance to fluconazole was underestimated whereas resistance to amphotericin B was overestimated using the CDC breakpoints of ≥32 and ≥2 mg/L, respectively. Vitek 2 minimun inhibitory concentrations (MICs) >4 mg/L indicated resistance to fluconazole and Vitek 2 MICs ≤16 mg/L indicated non-resistance to amphotericin B. Competing Interests: The authors declare no conflict of interest.
Databáze:	MEDLINE
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