Genomic Study of Methicillin-Resistant Staphylococcus aureus in Otitis Externa of Dogs and Cats in Urmia City-Iran

Members of the Staphylococcus genus are gram-positive cocci, catalase-positive, optional anaerobes, non-motile, oxidase-negative, and lack H₂S production. The aim of this study was to genotypically characterize methicillin-resistant Staphylococcus aureus (MRSA) isolated from Otitis Externa of dogs and cats in Urmia City. In this study, ۱۰۸ samples including ۵۶ dog samples and ۵۲ cat samples were randomly collected between fall ۲۰۲۴ and spring ۲۰۲۵ from ear exudates of dogs and cats visiting veterinary clinics, hospitals, and animal shelters in the city. Isolation of Staphylococcus aureus was performed through culturing and biochemical tests. The ۱۶S rRNA gene was used to confirm the species. To evaluate the methicillin resistance gene (mecA) in the isolated strains of Staphylococcus aureus, PCR was performed. The results of the culture indicated that, out of ۱۰۸ collected samples, ۱۱ (۱۹.۶۴%) were positive for Staphylococcus aureus in dogs and ۷ (۱۳.۴۶%) were positive in cats. In the antibiogram of the samples, it was observed that resistance to penicillin was highest at ۹۰.۹% in dog samples and lowest to methicillin at ۱۸.۱%. In cat samples, resistance to penicillin was highest at ۸۰%, while resistance to methicillin and vancomycin was also observed. Molecular results confirmed the۱۶S rRNA gene for ۱۱ isolates (۱۹.۶۴%) isolated from dog samples and ۷ isolates (۱۳.۴۶%) from cat samples. Among these, ۴ isolates (۷.۱۴%) from dog samples and ۱ isolate (۱.۹۱%) from cat samples carried the mecA gene. The results of this study demonstrated the spread of methicillin resistance in Staphylococcus aureus. However, very low resistance to methicillin was reported in this study.

کلیدواژه ها:

Dogs and cats ، Otitis Externa ، Staphylococcus aureus ، mecA gene ، Urmia