Comparison of Staphylococcus pettenkoferi Isolated from Human Clinical Cases and Cat Carriers Regarding Antibiotic Susceptibility and Biofilm Production

Staphylococcus pettenkoferi (S. pettenkoferi) is a rare opportunistic bacterium not commonly found in healthy individuals or animals. S. pettenkoferi has increasing clinical significance in both veterinary and human medicine due to its multidrug resistance and biofilm-forming ability. This study analyzed 12 isolates of S. pettenkoferi collected from humans and cats and identified them using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rRNA and partial rpoB gene sequencing. All of the S. pettenkoferi were phenotypically resistant to penicillin, and almost all (except one human strain) were resistant to methicillin. Antibiotic susceptibility testing revealed a high prevalence of multidrug resistance in all human strains with frequent resistance to beta-lactams, macrolides, and tetracyclines. A comparative analysis of human and feline isolates indicated the presence of shared resistance genes such as blaZ, mecA, and ermA. Biofilm production varied across isolates, with more potent biofilm formation abilities observed at elevated temperatures (39 degrees C) and time (48 h). These findings underscore the potential zoonotic risks of S. pettenkoferi and its role in managing multidrug-resistant infections.