Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 15 2 2023 04 19 325 335 Mona Eslami Department of Pathobiology, Faculty of Veterinary Specialized Science, Science and Research Branch, Islamic Azad University, Tehran, Iran Ali Ezabadi Department of Chemistry, Faculty of Basic Science, Central Tehran Branch, Islamic Azad University, Tehran, Iran Mansour Bayat Department of Pathobiology, Faculty of Veterinary Specialized Science, Science and Research Branch, Islamic Azad University, Tehran, Iran Behin Omidi Department of Biology, Faculty of Basic Science, Central Tehran Branch, Islamic Azad University, Tehran, Iran Pejman Mortazavi Department of Pathobiology, Faculty of Veterinary Specialized Science, Science and Research Branch, Islamic Azad University, Tehran, Iran 2022 05 07 2023 01 28 Background and Objectives: Previous researchers showed the antimicrobial ability of ionic liquids (ILs) on different infective agents. ILs can dissolve organic components, especially DNA molecules. Among synthesized eight binary ILs mixtures, we have chosen ([Met-HCl] [PyS]) IL for determining the antifungal ability of IL against Candida albicans cells. Materials and Methods: Well diffusion assay, chrome agar and Germ tube tests were used to detect the Candida samples. PCR, real-time-PCR, and flow cytometry tests were performed to determine the IL's rate of toxic ability. Results: Well diffusion assay revealed the diameters of the growth inhibition zones were the largest in IL with methionine and Proline amino acids. Minimum inhibitory concentration (MIC) and the Minimum fungicidal concentration (MFC) tests showed that they inhibited the growth of the C. albicans at a range from 250 µg/ml for sensitivity and 400 µg/ml for resistance, MIC average of all samples were 341.62 ± 4.153 µg/ml. IL reduced the expression of CDR1 and CDR2 the genes encoded by the major protein of ABC system transporter by 2.1 (P= 0.009) and 1.2 fold (P= 0.693), revealed by PCR and real time-PCR. In the flow cytometry test, there were increasing dead cells after treating with the ([Met-HCl] [PyS]) even in the most resistant strain. Conclusion: The novel IL was effective against the most clinical and standard C. albicans. https://ijm.tums.ac.ir/index.php/ijm/article/view/3708 https://ijm.tums.ac.ir/index.php/ijm/article/download/3708/1573