{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T00:37:23Z","timestamp":1787013443720,"version":"build-2736575974"},"reference-count":56,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2025,12,23]],"date-time":"2025-12-23T00:00:00Z","timestamp":1766448000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>This study evaluated the in vitro interaction of 5-fluorouridine (5-FUrd) with antifungal drugs and examined the role of efflux pumps in 5-FUrd resistance. Eleven reference Candida strains and twenty-three clinical C. albicans isolates from gynecological patients were tested. The antifungal activity of 5-FUrd alone and in combination with amphotericin B, fluconazole, voriconazole, caspofungin, and flucytosine was assessed using the checkerboard microdilution method. Efflux pump activity was evaluated using two inhibitors: carbonyl cyanide 3-chlorophenylhydrazone (CCCP) and verapamil. 5-FUrd exhibited antifungal activity against both the reference and clinical Candida strains, with MIC values ranging from 0.1 \u00b5g\/mL to 409.6 \u00b5g\/mL. The checkerboard assays revealed primarily no interactions in the reference Candida strains, whereas the reference C. albicans and clinical C. albicans isolates showed notable synergy between 5-FUrd and fluconazole, voriconazole, or caspofungin. The efflux pump inhibitors reduced the MICs of 5-FUrd in the resistant strains of C. lusitaniae, C. kefyr, and particularly C. krusei, suggesting efflux-mediated resistance mechanisms. This study highlights the potential of 5-FUrd, alone or combined with azoles or caspofungin, as an adjunct therapy against Candida infections. It also suggests that reduced susceptibility may be linked to efflux pump activity in certain strains.<\/jats:p>","DOI":"10.3390\/ijms27010171","type":"journal-article","created":{"date-parts":[[2025,12,23]],"date-time":"2025-12-23T14:27:47Z","timestamp":1766500067000},"page":"171","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["In Vitro Evaluation of 5-Fluorouridine as an Adjuvant to Antifungal Drugs and Molecular Insights into Resistance to This Compound in Candida Species"],"prefix":"10.3390","volume":"27","author":[{"given":"Monika","family":"Janeczko","sequence":"first","affiliation":[{"name":"Department of Molecular Biology, Faculty of Medicine, The John Paul II Catholic University of Lublin, 20-708 Lublin, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ewa","family":"Lenarczyk","sequence":"additional","affiliation":[{"name":"Department of Molecular Biology, Faculty of Medicine, The John Paul II Catholic University of Lublin, 20-708 Lublin, Poland"},{"name":"Doctoral School of the John Paul II Catholic University of Lublin, 20-950 Lublin, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1038\/s41572-024-00503-3","article-title":"Invasive candidiasis","volume":"10","author":"Kanj","year":"2024","journal-title":"Nat. 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