A Pragmatic Approach to Susceptibility Classification of Yeasts without EUCAST Clinical Breakpoints
EUCAST has established clinical breakpoints for the six most common <i>Candida</i> species and <i>Cryptococcus neoformans</i> but not for less common yeasts because sufficient evidence is lacking. Consequently, the question “How to interpret the MIC?” for other yeasts often a...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-01-01
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| Series: | Journal of Fungi |
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| Online Access: | https://www.mdpi.com/2309-608X/8/2/141 |
| _version_ | 1797478886739542016 |
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| author | Karen Marie Thyssen Astvad Sevtap Arikan-Akdagli Maiken Cavling Arendrup |
| author_facet | Karen Marie Thyssen Astvad Sevtap Arikan-Akdagli Maiken Cavling Arendrup |
| author_sort | Karen Marie Thyssen Astvad |
| collection | DOAJ |
| description | EUCAST has established clinical breakpoints for the six most common <i>Candida</i> species and <i>Cryptococcus neoformans</i> but not for less common yeasts because sufficient evidence is lacking. Consequently, the question “How to interpret the MIC?” for other yeasts often arises. We propose a pragmatic classification for amphotericin B, anidulafungin, fluconazole, and voriconazole MICs against 30 different rare yeasts. This classification takes advantage of MIC data for more than 4000 isolates generated in the EUCAST Development Laboratory for Fungi validated by alignment to published EUCAST MIC data. The classification relies on the following two important assumptions: first, that when isolates are genetically related, pathogenicity and intrinsic susceptibility patterns may be similar; and second, that even if species are not phylogenetically related, the rare yeasts will likely respond to therapy, provided the MIC is comparable to that against wild-type isolates of more prevalent susceptible species because rare yeasts are most likely “rare” due to a lower pathogenicity. In addition, the treatment recommendations available in the current guidelines based on the in vivo efficacy data and clinical experience are taken into consideration. Needless to say, it is of utmost importance (a) to ascertain that the species identification is correct (using MALDI-TOF or sequencing), and (b) to re-test the isolate once or twice to confirm that the MIC is representative for the isolate (because of the inherent variability in MIC determinations). We hope this pragmatic guidance is helpful until evidence-based EUCAST breakpoints can be formally established. |
| first_indexed | 2024-03-09T21:37:58Z |
| format | Article |
| id | doaj.art-1fed8071f2424012911ad97587a917d8 |
| institution | Directory Open Access Journal |
| issn | 2309-608X |
| language | English |
| last_indexed | 2024-03-09T21:37:58Z |
| publishDate | 2022-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Journal of Fungi |
| spelling | doaj.art-1fed8071f2424012911ad97587a917d82023-11-23T20:37:29ZengMDPI AGJournal of Fungi2309-608X2022-01-018214110.3390/jof8020141A Pragmatic Approach to Susceptibility Classification of Yeasts without EUCAST Clinical BreakpointsKaren Marie Thyssen Astvad0Sevtap Arikan-Akdagli1Maiken Cavling Arendrup2Unit of Mycology, Statens Serum Institut, DK-2300 Copenhagen, DenmarkDepartment of Medical Microbiology, Hacettepe University Medical School, Ankara 06100, TurkeyUnit of Mycology, Statens Serum Institut, DK-2300 Copenhagen, DenmarkEUCAST has established clinical breakpoints for the six most common <i>Candida</i> species and <i>Cryptococcus neoformans</i> but not for less common yeasts because sufficient evidence is lacking. Consequently, the question “How to interpret the MIC?” for other yeasts often arises. We propose a pragmatic classification for amphotericin B, anidulafungin, fluconazole, and voriconazole MICs against 30 different rare yeasts. This classification takes advantage of MIC data for more than 4000 isolates generated in the EUCAST Development Laboratory for Fungi validated by alignment to published EUCAST MIC data. The classification relies on the following two important assumptions: first, that when isolates are genetically related, pathogenicity and intrinsic susceptibility patterns may be similar; and second, that even if species are not phylogenetically related, the rare yeasts will likely respond to therapy, provided the MIC is comparable to that against wild-type isolates of more prevalent susceptible species because rare yeasts are most likely “rare” due to a lower pathogenicity. In addition, the treatment recommendations available in the current guidelines based on the in vivo efficacy data and clinical experience are taken into consideration. Needless to say, it is of utmost importance (a) to ascertain that the species identification is correct (using MALDI-TOF or sequencing), and (b) to re-test the isolate once or twice to confirm that the MIC is representative for the isolate (because of the inherent variability in MIC determinations). We hope this pragmatic guidance is helpful until evidence-based EUCAST breakpoints can be formally established.https://www.mdpi.com/2309-608X/8/2/141rare yeastantifungal susceptibility testingEUCASTclinical breakpointepidemiological cut-off valueECOFF |
| spellingShingle | Karen Marie Thyssen Astvad Sevtap Arikan-Akdagli Maiken Cavling Arendrup A Pragmatic Approach to Susceptibility Classification of Yeasts without EUCAST Clinical Breakpoints Journal of Fungi rare yeast antifungal susceptibility testing EUCAST clinical breakpoint epidemiological cut-off value ECOFF |
| title | A Pragmatic Approach to Susceptibility Classification of Yeasts without EUCAST Clinical Breakpoints |
| title_full | A Pragmatic Approach to Susceptibility Classification of Yeasts without EUCAST Clinical Breakpoints |
| title_fullStr | A Pragmatic Approach to Susceptibility Classification of Yeasts without EUCAST Clinical Breakpoints |
| title_full_unstemmed | A Pragmatic Approach to Susceptibility Classification of Yeasts without EUCAST Clinical Breakpoints |
| title_short | A Pragmatic Approach to Susceptibility Classification of Yeasts without EUCAST Clinical Breakpoints |
| title_sort | pragmatic approach to susceptibility classification of yeasts without eucast clinical breakpoints |
| topic | rare yeast antifungal susceptibility testing EUCAST clinical breakpoint epidemiological cut-off value ECOFF |
| url | https://www.mdpi.com/2309-608X/8/2/141 |
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