Methicillin-resistant Staphylococcus aureus in a Turkish hospital: characterization of clonal types and antibiotic susceptibility

Introduction: The assessment of the clonal spread of methicillin resistant Staphylococcus aureus (MRSA) in nosocomial and community-acquired infections through characterization of the isolates is critical for tracking the evolution of the epidemics, implementing effective control measures, and preventing future outbreaks of MRSA. In this context, it is aimed with this study to determine the clonal relationships between the S. aureus isolates obtained from the patients receiving treatment in the intensive-care units of a state hospital in Turkey. Methodology: A total of 80 MRSA isolates obtained from the patients receiving treatment in three different intensive-care units were analyzed for their antibiotic susceptibilities, pulsed-field gel electrophoresis profiles, and multilocus sequence types. Results: The dendrogram of the pulsed-field gel electrophoresis profiles revealed two major pulsed-field gel electrophoresis pulsotypes: A and B, which were further divided into two (A1 and A2) and four (B1-B4) subgroups, respectively. Multilocus sequence typeanalysis indicated that all isolates belonged to a single MRSA clone, sequence type 239. No significant difference was found between the antibiotic sensitivity profiles of strains isolated from different intensive-care units. All of the strains were sensitive to linezolid and vancomycin. Conclusions: It was concluded that the MRSA strains isolated from the patients receiving treatment at the intensive-care units of the hospital constituted two major pulse-field types and belonged to the ST239 lineage, one of the most extensively distributed MRSA lineages throughout the world.