Clinical characterization of methicillin-resistant Staphylococcus schleiferi (MRSS) strains isolated from healthy dogs and dogs with otitis externa = Clinical characterization of methicillin-resistant Staphylococcus schleiferi (MRSS) strains isolated from healthy dogs and dogs with otitis externa

다국어 초록 (Multilingual Abstract)

Introduction: Staphylococcus schleiferi has been implicated as an opportunistic pathogen of canine skin and ear infections. Recently, emergence and spread of antibiotic-resistant S. schleiferi, especially methicillin-resistant S. schleiferi (MRSS), had been a growing concern in both human and veterinary medicine.
Materials and methods: In this investigation, using a total of 31 S. schleiferi strains isolated from healthy dogs and dogs with otitis externa, we examined: i) antibiotic resistance profiles; ii) presence of mecA gene & SCCmec type; iii) abilities to form biofilm; and iv) susceptibilities to host defense-cationic antimicrobial peptide (HD-CAPs).
Results: Among the 31 S. schleiferi isolates, 7 isolates (23%) were resistant to methicillin (MRSS) and 8 isolates (26%) were resistant to more than 2 antibiotics tested. Analyses of SCCmec type in the MRSS strains revealed that the most predominant type was SCCmec V (6/7 MRSS strains). Although limited number of S. schleiferi strains were used, MRSS strains appeared to have enhanced ability to form biofilm under static condition versus the MSSS strains. Furthermore, MRSS strains displayed significantly higher resistance to the canine cathelicidin (K9CATH) compared with that of MSSS strains.
Conclusions: The presence of MRSS strains, particularly with multiple antibiotic resistant MRSS strains, suggest that continuous monitoring of antibiotic resistance along with studies of virulence development in S. schleiferi is necessary.
[This work was carried out by the support of Cooperative Research Program for Agriculture Science & Technology Development (Project No. PJ012811 to S.J.Y) Rural Development Administration, Republic of Korea]