Prevalence and characterization of methicillin-resistant Staphylococcus pseudintermedius from symptomatic companion animals in Northern Italy: Clonal diversity and novel sequence types.

• Methicillin-resistant S. pseudintermedius (MRSP) has emerged worldwide as a concern in small animal clinics. • Internationally established and novel MRSP clones are present in Italy. • MRSP isolates show a phenotypic and genotypic multidrug resistance, without diversity among different clonal lineage. • The MDR traits in the MRSP population highlights the importance of rational usage of antimicrobials in the dog population. • The zoonotic potential of MRSP of animal origin should not be underestimated. The aim of this study was to assess the prevalence, the genotypic diversity, the antimicrobial resistance traits of canine and feline clinical methicillin-resistant Staphylococcus pseudintermedius (MRSP) isolates in a diagnostic laboratory in Italy during 2015-2016. All isolates were characterized by multilocus sequence typing (MLST), staphylococcal cassette chromosome (SCC)- mec typing and staphylococcal protein A (spa)-typing. The resistance profiles were assessed by antimicrobial susceptibility testing and confirmed genotypically by the detection of mecA gene and by microarray analyses. The prevalence of MRSP isolates was high (31.6%). All the strains were multidrug resistant and the most frequent clone was ST71-SCC mec type II-III. These results confirm a high prevalence of MRSP amongst clinical samples from pets in Italy. These isolates show multidrug resistance features that are of concern both in veterinary and human medicine for clinical and epidemiological reasons. [ABSTRACT FROM AUTHOR]