Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 18 4 2026 08 04 607 614 Nima Niaee Barmachi Department of Veterinary Pathobiology, SR.C., Islamic Azad University, Tehran, Iran Mansour Bayat Department of Veterinary Pathobiology, SR.C., Islamic Azad University, Tehran, Iran Nakisa Sohrabi Haghdoost Department of Veterinary Pathobiology, SR.C., Islamic Azad University, Tehran, Iran Batool Ghorbaniyekta Department of Physiology, Faculty of Medicine, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran Leila Eini Farahani Department of Basic Sciences, Faculty of Veterinary Medicine, SR.C., Islamic Azad University, Tehran, Iran 2025 11 09 2026 06 25 Background and Objectives: Malassezia spp. are lipid-dependent yeasts that colonize the skin of humans and animals and may act as opportunistic pathogens. This study aimed to characterize virulence-associated enzymes and their encoding genes in Malassezia spp. isolated from companion animals in northern Iran. Materials and Methods: A total of 300 clinical samples were collected from dogs and cats with dermatological or otic lesions. Species identification was performed using ITS-based PCR. Multiplex PCR was used to detect LIP, PLB, and KER genes. Enzymatic activity was evaluated using the Pz index. Statistical analyses included Chi-square and Spearman’s correlation tests (p < 0.05). Results: Eighty isolates were identified as Malassezia pachydermatis (87.5%) and Malassezia nana (12.5%). LIP, PLB, and KER genes were detected in 90%, 62.5%, and 50% of isolates, respectively. Strong enzymatic activity (Pz ≤ 0.69) was observed in 41.2% of isolates. A significant association was found between the presence of the PLB gene and phospholipase activity. Conclusion: Malassezia pachydermatis was the predominant species. Virulence-associated genes were associated with higher enzymatic activity, supporting their role in pathogenic potential. https://ijm.tums.ac.ir/index.php/ijm/article/view/5916 https://ijm.tums.ac.ir/index.php/ijm/article/download/5916/1920