Species distribution and antimicrobial resistance of Staphylococcus spp. isolated from dogs and cats in Poland: a retrospective laboratory-based study

Introduction Staphylococcus spp. are important opportunistic pathogens of companion animals and an increasingly relevant component of the antimicrobial resistance problem in veterinary medicine. The aim of this study was to evaluate the species distribution and antimicrobial susceptibility patterns of Staphylococcus spp. isolated from dogs and cats in Poland, with particular emphasis on MIC-based testing. Methods A total of 281 records of Staphylococcus isolates obtained from routine diagnostic submissions to a commercial veterinary laboratory were included. Bacterial identification was performed using MALDI-TOF-MS, and antimicrobial susceptibility was assessed using a commercial MIC panel. Results After exclusion of nitrofurantoin from comparative analyses, the highest resistance rates were observed for penicillin (86.5%), trimethoprim-sulfamethoxazole (77.2%), and tetracycline (68.0%), whereas no resistant isolates were detected for teicoplanin or vancomycin. Direct MIC-based interpretation of ampicillin-sulbactam yielded no resistant isolates. Staphylococcus pseudintermedius was the predominant species in dogs, while Staphylococcus felis predominated in cats. Dog-derived isolates showed a significantly higher resistance burden than cat-derived isolates, and multidrug resistance was significantly more frequent in isolates obtained from dogs than cats (72.5% vs. 55.7%). Among the four dominant species, resistance burden and multidrug resistance rates were highest in S. pseudintermedius . Significant between-host differences after multiple-testing correction were retained for erythromycin and trimethoprim-sulfamethoxazole, both being more frequent in canine isolates. Discussion Companion animal staphylococci in Poland exhibit substantial resistance to several commonly used antimicrobials, with S. pseudintermedius representing the major driver of resistance in dogs. These findings highlight the need for continued surveillance and prudent antimicrobial stewardship in small animal practice.