Phenotypic and Genotypic Diversity of Methicillin-Resistant Staphylococci in Dermatological Pets and Their Owners

Limited data exist regarding how staphylococcal isolates from infected pets and their owners compare with domestic and international strains. In this study, swabs were collected from skin lesions of 160 pets and nasal cavities of 100 owners in Wuhan, China. Isolates were tested for antimicrobial susceptibility and the presence of resistance genes. Methicillin-resistant staphylococci (MRS, defined by the presence of mecA) were characterized using MLST, spa, and SCCmec typing. Among 268 staphylococcal isolates, 105 were coagulase-positive (69 S. pseudintermedius, 33 S. aureus, 3 S. schleiferi subsp. coagulans). S. pseudintermedius exhibited 91.3% susceptibility to oxacillin but 89.9% resistance to penicillin. Conversely, S. aureus was 97.0% susceptible to gentamicin and levofloxacin, yet 97.0% resistant to trimethoprim-sulfamethoxazole. Multidrug resistance was observed in 85.5% and 51.5% of these two species, respectively. Among the 26 mecA-positive isolates (21 MRSP, 5 MRSA), MLST analysis revealed household-level similarities in phenotypes and genotypes (e.g., ST25, ST22), suggesting potential transmission between pets and owners. Furthermore, these sequence types were closely related to globally prevalent lineages, indicating broader genetic backgrounds. Notably, immediate handwashing after pet contact reduced the likelihood of transmission (p = 0.04), especially when pets presented with dermatological disease. This study provides insights into infection control and resistance transfer.