en Interaction of Candida albicans With Combination of Fluconazole/Clotrimazole: Effect on Hyphae Formation and Expression Levels of Hyphal Wall Protein 1 (HWP1) قارچ شناسی Mycology پژوهشي Research <strong>Background and Aims:</strong><em> Candida albicans</em> is the most prevalent opportunistic human pathogen. Therapeutic options for <em>Candida </em>infections are limited to available antifungal drugs. The aim of this study was to investigate the effect of combination of fluconazole/clotrimazole on <em>C. albicans</em> hyphae formation.<br> <strong>Materials and Methods:</strong> We have established the effectiveness combination of fluconazole/clotrimazole on <em>C. albicans</em> hyphae formation. Interaction of <em>C. albicans</em> with combination of fluconazole/clotrimazole were performed using the CLSI standard method and time-killing curves. In order to investigate the effectiveness combination of fluconazole/clotrimazole on<em> C. albicans</em> hyphae formation, XTT and crystal violet (CV) assays as well as scanning electron microscopy (SEM) and expression of <em>HWP1 </em>gene were carried out.<br> <strong>Results:</strong> The interaction of <em>C. albicans</em> with fluconazole and clotrimazole resulted in synergistic, partial synergistic and indifferent effects. The interaction of fluconazole/clotrimazole were confirmed by time-killing curves. In XTT and CV assays, <em>C. albicans</em> treated with combination of fluconazole/clotrimazole reduced metabolic activity and hyphae formation. Images taken by SEM microscopy indicated the effectiveness on hyphae disruption. According to relative real time RT-PCR analysis, the mean Ct values revealed the significant decrease in expression level of the <em>HWP1 </em>gene (<em>P</em><0.05). A 2.86- and 2.33-fold decrease in <em>HWP1 </em>gene expression was observed in combination of fluconazole/clotrimazole treatment at 2&times; MIC and 1&times; MIC concentrations, respectively (<em>P</em><0.05).<br> <strong>Conclusions: </strong>We confirmed that the hyphae is a target for the combination of fluconazole/clotrimazole in&nbsp;<em>C. albicans</em>.<em> HWP1 </em>gene is likely to be considered as a probable targets synergistic interaction of fluconazole/clotrimazole against&nbsp;<em>C</em>.&nbsp;<em>albicans.</em> <strong>Background and Aims:</strong><em> Candida albicans</em> (<em>C.&nbsp;albicans</em>) is the most common opportunistic human pathogen. Therapeutic options for <em>Candida </em>infections are limited to available antifungal drugs. The aim of this study was to investigate the effects of fluconazole/clotrimazole (FLU/CLT) on <em>C. albicans</em> hyphae formation.<br> <strong>Materials and Methods:</strong> We have established the effectiveness of the combination of FLU/CLT on <em>C. albicans</em> hyphae formation. Interaction of <em>C. albicans</em> with combination of FLU/CLT was performed using the CLSI guidelines and time-killing curves<em>. </em>We investigated the anti-hyphal activities of combination of FLU/CLT against <em>C. albicans</em> using XTT and crystal violet &nbsp;&nbsp;assays as well as scanning electron microscopy and expression of <em>HWP1</em> gene.<br> <strong>Results:</strong> The interaction of <em>C. albicans</em> with FLU/CLT resulted in synergistic, partial synergistic and indifferent effects. The interaction of FLU/CLT were confirmed by time-killing curves. FLU/CLT combined resulted in the reduction of metabolic activity and hyphae formation in <em>C.&nbsp;albicans</em>. Images taken by scanning electron microscopy indicated the effectiveness on hyphae disruption. According to relative real time polymerase chain reaction analysis, the mean Ct values revealed the significant decrease in expression level of the <em>HWP1 </em>gene. A 2.86- and 2.33-fold decrease in <em>HWP1 </em>gene expression was observed in combination of FLU/CLT treatment at 2&times; minimum inhibitory concentration and 1&times; minimum inhibitory concentration, respectively (p=0.002).<br> <strong>Conclusions: </strong>We confirmed that the hyphae is a target for the combination of FLU/CLT in <em>C.&nbsp;albicans</em>.<em> HWP1 </em>gene is likely to be considered as a probable targets synergistic interaction of FLU/CLT against&nbsp;<em>C</em>.&nbsp;<em>albicans.</em> Candida albicans, Clotrimazole, Fluconazole, Hyphae Candida albicans, Clotrimazole, Fluconazole, Hyphae 110 120 http://ijml.ssu.ac.ir/browse.php?a_code=A-10-318-1&slc_lang=en&sid=1 Sakineh Jam Shahriari سکینه جام شهریاری mnlzdh@gmail.com No Department of Microbiology, Yasooj Branch, Islamic Azad University, Yasooj, Iran دانشگاه آزاد اسلامی Fahimeh Alizadeh فهیمه علیزاده mnalizadeh@yahoo.com 0000-0002-7074-0464 Yes Department of Microbiology, Yasooj Branch, Islamic Azad University, Yasooj, Iran. گروه زیست شناسی-میکروبیولوژی، واحد یاسوج، دانشگاه آزاد اسلامی، یاسوج، ایران Alireza Khodavandi علیرضا خداوندی alireza_khodavandi@yahoo.com 0000-0001-9498-9822 No Department of Biology, Gachsaran Branch, Islamic Azad University, Gachsaran, Iran گروه زیست شناسی، واحد گچساران ، دانشگاه آزاد اسلامی ، گچساران ، ایران