Meticillin-resistant Staphylococcus aureus: spread of specific lineages among patients in different wards at a Brazilian teaching hospital

This study aimed to characterize meticillin-resistant Staphylococcus aureus (MRSA) lineages circulating in a Brazilian teaching hospital. MRSA isolates from nasal swabs were evaluated to assess antimicrobial susceptibility, staphylococcal cassette chromosome mec (SCCmec), Panton-Valentine leucocidin status, pulsed-field gel electrophoresis profile and multi-locus sequence type (MLST) analysis. Eighty-three MRSA isolates were analysed. SCCmec III (43.4%) and IV (49.4%) were predominant. ST1-IV (USA400) was more common in internal medicine (P = 0.002) whereas 'clone M' (SCCmec III) was more common in the medical and surgical intensive care unit (P = 0.004), and all isolates were ST5-IV (USA800) in dermatology (P < 0.001). These data improved the understanding of the MRSA epidemiology inside the hospital and helped to establish effective control measures.