Comparison of the prevalence, antibiotic resistance patterns, and biofilm formation ability of methicillin-resistant Staphylococcus pseudintermedius in healthy dogs and dogs with skin infections.

Staphylococcus pseudintermedius (S. pseudintermedius), found on dogs' skin and mucous membranes, can act as an opportunistic pathogen causing skin, ear, and other tissue infections. Due to the possibility of zoonotic transmission of them, it is necessary to investigate the prevalence of S. pseudintermedius, especially the antimicrobial-resistant strains, in pets. In this study, the prevalence, antimicrobial resistance patterns, and biofilm formation ability of methicillin-resistant S. pseudintermedius (MRSP) were investigated and compared in 50 healthy dogs and 50 dogs with skin infections. The prevalence of S. pseudintermedius was not significantly different between healthy dogs (40%) and dogs with skin infections (50%). No significant difference was found in the prevalence of MRSP between healthy dogs (12%) and dogs with skin infections (18%). A total of 81.8% of S. pseudintermedius isolates were biofilm producers. The frequencies of antibiotic resistance (except for gentamicin), multidrug resistance (MDR), and biofilm formation ability were not significantly different between S. pseudintermedius isolates of healthy dogs and dogs with skin infections. The frequencies of resistance to penicillin and tetracycline, MDR, and biofilm production abilities were significantly higher among MRSP than methicillin-susceptible S. pseudintermedius (MSSP). The frequency of oxacillin resistance was significantly higher among weak or moderate biofilm producers than non-biofilm producers. The frequency of resistance to erythromycin was significantly higher among moderate biofilm producers than non-biofilm producers or weak biofilm producers. High frequencies of biofilm-producer S. pseudintermedius isolates and their resistance to antibiotics can affect the success of treatment of infections caused by these strains.