AUTHOR=Schwarz Patrick , Nikolskiy Ilya , Bidaud Anne-Laure , Sommer Frank , Bange Gert , Dannaoui Eric 

TITLE=In Vitro Synergy of Isavuconazole Combined With Colistin Against Common Candida Species

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.892893

DOI=10.3389/fcimb.2022.892893

ISSN=2235-2988

ABSTRACT=<p>Interactions of isavuconazole and colistin were evaluated against 57 common <italic>Candida</italic> strains belonging to the species <italic>Candida albicans</italic> (n = 10), <italic>Candida glabrata</italic> (n = 10), <italic>Candida kefyr</italic> (n = 8), <italic>Candida krusei</italic> (n = 10), <italic>Candida parapsilosis</italic> (n = 9), and <italic>Candida tropicalis</italic> (n = 10) by a broth microdilution checkerboard technique based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) reference methodology for antifungal susceptibility testing. Results were analyzed with the fractional inhibitory concentration index and by the response surface analysis. Interpretation by the fractional inhibitory concentration index showed synergy for 50%, 80%, 90%, and 90% of the <italic>C. kefyr</italic>, <italic>C. krusei</italic>, <italic>C. glabrata</italic>, and <italic>C. tropicalis</italic> strains, respectively. Combination of isavuconazole with colistin against <italic>C. albicans</italic> and <italic>C. parapsilosis</italic> exhibited only indifference for 100% and 90% of the strains, respectively. The results were confirmed by response surface analysis for all species except for <italic>C. glabrata</italic>, for which an indifferent interaction was found for the majority of strains. Antagonistic interaction was never seen regardless of the interpretation model was used.</p>