The prevalence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) as a cause of infectious disease in companion animals remains unknown. The emergence of MRSP is a challenge in veterinary medicine as multidrug-resistant strains began to emerge, resulting in treatment failures. This study provides an overview of the characterization of S. pseudintermedius strains from clinical pet samples and the prevalence of MRSP strains. A total of 123 S. pseudintermedius strains were characterized by phenotypic testing and the MALDI-TOF technique and evaluated for susceptibility to methicillin and the presence of the mecA gene. Of these, 49 (39.8%) were identified as MRSP. The results confirm the importance of monitoring resistant pathogens and the need for further studies to determine the prevalence of MRSP in companion animals. The prevalence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) as a cause of infectious disease in companion animals remains unknown. This study provides an overview of the characterization of S. pseudintermedius strains from clinical pet samples and the prevalence of MRSP strains. A total of 123 S. pseudintermedius strains were characterized by phenotypic testing and the MALDI-TOF technique and evaluated for susceptibility to methicillin and the presence of the mecA gene. Of these, 49 (39.8%) were identified as MRSP. The results confirm the importance of monitoring resistant pathogens and the need for further studies to determine the prevalence of MRSP in companion animals.

Staphylococcus spp. plays a significant role in the etiology of bovine mastitis. Staphylococcus aureus is considered the most important species due to the high prevalence and the difficulty of in vivo treatment that is related to the expression of virulence factors and biofilm formation. This study aimed to detect the phenotypic expression of the biofilm formation in 20 S. aureus isolated from bovine mastitis and to evaluate the expression and regulation of genes involved in its production. MALDI-TOF and phenogenotypic identification assays were performed to characterize the isolates. The phenotypic biofilm production and the presence of icaA and icaD and bap genes were evaluated. The Agr system was typified (agr I, agr II, agr III and agr IV) and its regulator (agr RNAIII) was detected. Furtherly, Real-time PCR (qPCR) was performed at chosen times to quantify the expression of icaA, icaD and hld genes in three selected isolates. All 20 strains were biofilm producers and most presented icaA and icaD genes. Only one isolate presented the bap gene. The agr gene type II showed a prevalence of 70%. Transcriptional analysis revealed increased expression of ica genes at eight hours of growth. These results confirm that polysaccharides production mediated by the icaADBC operon genes is an essential mechanism to the biofilm formation and contributes to the early stages of bacterial growth.