Faculty of Veterinary Medicine, Urmia University Veterinary Research Forum 2008-8140 17 3 2026 03 01 Molecular investigation of biofilm-forming genes in staphylococci isolated from dogs in Ilam, Iran 191 197 733529 10.30466/vrf.2025.2052777.4656 EN Negar Soltani Department of Microbiology, Faculty of Veterinary Sciences, Ilam University, Ilam, Iran Mostafa Nemati Department of Microbiology, Faculty of Veterinary Sciences, Ilam University, Ilam, Iran 0000-0002-6042-082X Fazel Pourahmad Department of Microbiology, Faculty of Veterinary Sciences, Ilam University, Ilam, Iran 0000-0003-0342-1735 Journal Article 2025 02 06 Biofilm formation is a key virulence factor in <em>Staphylococcus aureus</em>, contributing to bacterial persistence, antimicrobial resistance, and chronic infections. This study aimed to investigate the presence of biofilm-associated genes (fib, fnbA, fnbB, clfA, and clfB) in S. aureus isolates from dogs in Ilam, Iran. From December 2022 to September 2023, 250 swab samples were collected from nasal, oral, and rectal sites of dogs, yielding 81 S. aureus isolates confirmed by PCR amplification of the nuc gene. The prevalence of biofilm-associated genes varied, with clfA, clfB, and fnbA detected in 98.80% of isolates, fib in 63.00%, and fnbB in 16.00%. Notably, fnbA, clfA, and clfB were present in all rectal isolates, while fnbB was absent in this group. The findings highlighted the widespread presence of biofilm-related genes in <em>S. aureus</em> from dogs, suggesting their potential role in colonization and zoonotic transmission. The high prevalence of adhesion-associated genes underscored the need for monitoring biofilm-forming S. aureus in companion animals to mitigate antimicrobial resistance and public health risks. https://vrf.iranjournals.ir/article_733529_2f313bd1402a6771d40c71763013d07a.pdf