en Host-pathogen interactions and susceptibility factors Host-pathogen interactions and susceptibility factors Original article Original article <span style="font-size:11pt"><span style="line-height:normal"><span sans-serif="" style="font-family:Calibri,"><b><span style="font-size:10.0pt"><span new="" roman="" style="font-family:" times="">Introduction</span></span></b><span style="font-size:10.0pt"><span new="" roman="" style="font-family:" times="">: Vulvovaginal candidiasis (VVC) is a prevalent and often recurrent condition affecting an estimated 75% of women worldwide. <i>Candida albicans</i> is a primary fungal pathogen responsible for a significant proportion of VVC cases. This cross-sectional study investigated the expression levels of two critical virulence genes, <i>ALS1</i> and <i>HWP1</i>, in <i>C. albicans</i> isolates from women diagnosed with VVC. Moreover, we examined the effect of copper nanoparticles on the expression of these genes, exploring their potential as a novel antifungal therapy for VVC treatment. <b>Methods</b>: This study recruited 30 patients diagnosed with VVC from Razi Hospital, Iran. We employed polymerase chain reaction (PCR) to confirm the presence of the <i>ALS1</i> and <i>HWP1</i> genes in <i>C. albicans</i> isolates. Subsequently, we extracted RNA from the isolates and assessed the effect of copper nanoparticles on the expression of <i>ALS1</i> and <i>HWP1</i> genes using quantitative real-time PCR (qRT-PCR). <b>Results</b>: Of the 30 <i>C. albicans</i> clinical isolates analyzed, 17 (56.7%) harbored both <i>HWP1</i> and <i>ALS1</i> virulence genes. Copper nanoparticles significantly downregulated the expression of these genes. Notably, treatment with 8.8 &mu;g/mL copper nanoparticles resulted in a significant reduction of <i>HWP1</i> gene expression, while 3.23 &mu;g/mL copper nanoparticles led to a significant decrease in <i>ALS1</i> gene expression. <b>Conclusion</b>: This study identified the presence of <i>ALS1</i> and <i>HWP1</i> virulence genes in <i>C. albicans</i> isolates from women with VVC and demonstrated the potential of copper nanoparticles to downregulate their expression. These findings offer promising insights into the development of novel antifungal therapies for VVC treatment. However, further investigations with larger, more diverse cohorts and comprehensive analyses are necessary to fully understand the effects of copper nanoparticles on <i>C. albicans</i> gene expression and their potential clinical applications for VVC management. </span></span></span></span></span> Vulvovaginal candidiasis (VVC), Candida albicans, Copper nanoparticles, ALS1, HWP1, Downregulation, Antifungal therapy 35 41 http://jommid.pasteur.ac.ir/browse.php?a_code=A-10-380-1&slc_lang=en&sid=1 Mahmoud Hassan Shahryari mahmoud_hassansh@ymail.com 0000-0001-9000-9268 No Department of Biology, Central Tehran Branch, Islamic Azad University, Tehran, Iran Roudabeh Behzadi Andouhjerdi rahabehzadi@yahoo.com 0000-0003-0961-6672 No Department of Biology, Central Tehran Branch, Islamic Azad University, Tehran, Iran Mehrnoosh Hasan Shahriari shahriarim@yahoo.com 0000-0002-5494-1864 Yes Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran