Antifungal Resistance among Less Prevalent <i>Candida</i> Non-<i>albicans</i> and Other Yeasts versus Established and under Development Agents: A Literature Review

• Main Authors: Ana Espinel-Ingroff, Emilia Cantón, Javier Pemán
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Series: Journal of Fungi
• Subjects: non-prevalent <i>Candida</i>; antifungal resistance; new and established antifungal agents; <i>Candida</i>-non <i>albicans</i>; other yeast pathogens
• Online Access: https://www.mdpi.com/2309-608X/7/1/24

Fungal diseases and antifungal resistance continue to increase, including those caused by rare or emerging species. However, the majority of the published in vitro susceptibility data are for the most common fungal species. We reviewed the literature in order to pool reference minimal inhibitory concentration (MIC) data (Clinical and Laboratory Standards Institute—CLSI and European Committee on Antimicrobial Susceptibility—EUCAST) for rare/non-prevalent <i>Candida</i><i> </i>and other yeast species. MIC results were compared with those for <i>Candida albicans</i>, <i>C. glabrata</i>, and <i>C. </i><i>krusei</i>. Data were listed for twenty rare and emerging <i>Candida </i>spp., including <i>C. </i><i>auris</i>, as well as two <i>Cryptococcus</i> spp., two <i>Trichosporon</i> spp., <i>Saccharomyces cerevisiae</i> and five <i>Malassezia</i> spp. The best detectors of antimicrobial resistance are the breakpoints, which are not available for the less common <i>Candida </i>species. However, epidemiological cutoff values (ECVs/ECOFFs) have been calculated using merely in vitro data for both reference methods for various non-prevalent yeasts and recently the CLSI has established ECVs for other <i>Candida </i>species. The ECV could identify the non-wild type (NWT or mutants) isolates with known resistance mechanisms. Utilizing these ECVs, we were able to report additional percentages of NWT, especially for non-prevalent species, by analyzing the MIC distributions in the literature. In addition, since several antifungal drugs are under development, we are listing MIC data for some of these agents.