en ميکروب شناسي Microbiology Research Article Research Article <div style="text-align: justify;"><span style="font-size:12px;"><span style="font-family:Times New Roman;"><b>Background:</b> Biofilm formation in <i>Staphylococcus aureus</i> (<i>S. aureus</i>), mediated by the <i>ica</i> operon, is a key virulence factor. This study examined how different glucose-supplemented broth culture media influence biofilm production and <i>ica</i> gene expression in <i>S. aureus</i>.<br> <b>Methods:</b> The phenotypic ability to adhere to a polystyrene surface and produce a slime layer was evaluated using the microtiter plate test (MtP) and Congo red tube test, respectively. Using PCR, the presence of the intercellular adhesion (<i>ica</i>) locus in <i>S. aureus</i> strains was confirmed. Subsequently, quantitative real-time RT-PCR was performed to investigate <i>icaA</i> transcription in various media, including tryptic soy broth (TSB), brain-heart infusion broth (BHIB), nutrient broth (NB), and Mueller-Hinton broth (MHB), containing 0, 0.25, 0.5, 1, and 2% glucose.<br> <b>Results:</b> Our results showed that although all studied strains adhered to the wells of polystyrene microtiter plates, the optimal rate of biofilm formation was observed in TSB medium containing 1% glucose. However, biofilm formation was not significantly different in NB, MHB, and BHIB media. Supplementation of all media with 1% glucose resulted in the highest biofilm production, and <i>icaA</i> transcription increased in all media after glucose addition up to 1%.<br> <b>Conclusion</b>: The results of the present study indicated that TSB medium supplemented with 1% glucose was the most appropriate medium for evaluating biofilm formation by <i>S. aureus</i> isolates.</span></span></div> Biofilm, Staphylococcus aureus, Culture Media, Glucose, Quantitative Real Time PCR 0 0 http://mlj.goums.ac.ir/browse.php?a_code=A-10-1738-1&slc_lang=en&sid=1 Aram Sharifi a.sharifi@uok.ac.ir 100319475328460032943 100319475328460032943 No Department of Animal Science, Faculty of Agriculture, University of Kurdistan, Sanandaj, Kurdistan, Iran Abdolmajid Mohammadzadeh mohammadzadeh@basu.ac.ir 100319475328460032944 100319475328460032944 Yes Department of Pathobiology, Faculty of Veterinary Medicine, Bu-Ali Sina University, Hamedan, Iran Pezhman Mahmoodi mahmoodi_pezhman@yahoo.com 100319475328460032945 100319475328460032945 No Department of Pathobiology, Faculty of Veterinary Medicine, Bu-Ali Sina University, Hamedan, Iran Taghi Zahraei Salehi tsalehi@ut.ac.ir 100319475328460032946 100319475328460032946 No Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran