Molecular characterization of methicillin-resistant Staphylococcus schleiferi isolated from canine skin in Korea

Abstract

Staphylococcus schleiferi can cause infections in dogs and humans, and the methicillin resistance of S. schleiferi makes it a particularly large threat to public health. This study was conducted molecular characterization and the antimicrobial susceptibility of S. schleiferi from dogs in Korea and compared the results with those from other countries. We collected 185 staphylococcal isolates from canine pyoderma and otitis externa. Staphylococci were identified using the microbiology identification system and PCR. Antibiotic susceptibility data were collected using the disk diffusion method, and the SCCmec type and direct repeat unit (dru) was determined by PCR. S. schleiferi was the second most prevalent species (17/185, 9.2%). Seven methicillin-resistant S. schleiferi (MRSS) (7/17, 41.1%) isolates were detected and confirmed as SCCmec type V which is the most prevalent type in MR Staphylococcus pseudintermedius from veterinary staff and animals in Korea. mec-associated dru typing revealed two dru types (dt): dt11a and dt9bd. The dt11a type, which is usually observed in Staphylococcus pseudintermedius, was found in six MRSS isolates (85.7%), and one isolate was dt9bd type. This study is the first report on SCCmec and dru typing of S. schleiferi in Korea. SCCmec typing and antimicrobial susceptibility tests revealed that MRSS is disseminating and causing skin infections in dogs in Korea. SCCmec typing results were the same as those reported in Thailand, but different from those in the USA (SCCmec type IV) and India (SCCmec type I). The result of SCCmec type and dru type(dt) 11a suggest that methicillin resistance in MRSS varies with geographical location and have close correlation with Staphylococcus pseudintermedius. Our results provide important insights into the characteristic and molecular genetics of MRSS strains in Korea and may aid in the monitoring of MRSS spread throughout the country.