Updating of in vitro antifungal susceptibility tests

Fungal diseases, including those caused by (multi)drug-resistant fungi, still represent a global public health concern. Information on the susceptibility of these microorganisms to antifungal agents must be quickly produced to help clinicians initiate appropriate antifungal therapies. Unfortunately, antifungal susceptibility tests are not as developed or widely implemented as antibacterial tests, being similar in design, accuracy and reproducibility, but also laborious and slow. In this article, we review the methods of in vitro susceptibility testing, both reference (CLSI and EUCAST), commercial and new methods based on proteomics (MALDI-TOF MS) and in the detection of resistance genes by nucleic acid amplification techniques. In addi-tion, we discuss the newly established clinical breakpoints, as well as the epidemiological cut-off points, which constitute a new category that can help in the early identification of isolates that have acquired resistance mechanisms. We also discuss the advantages and limitations of each of the methods studied. Therefore, we can conclude that, although there has been much progress in studies of in vitro susceptibility testing to antifungals, there are still limitations in its application in the daily routine of microbiology labo-ratories, although it seems that the future is promising with the new technologies based on proteomics and nucleic acid amplification. Supplement information: This article is part of a supplement entitled «SEIMC External Quality Control Programme. Year 2016», which is sponsored by Roche, Vircell Microbiologists, Abbott Molecular and Francisco Soria Melguizo, S.A. © 2019 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosasy Microbiología Clínica. All rights reserved.