RESUMO
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.
Assuntos
Portador Sadio/epidemiologia , Infecção Hospitalar/epidemiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/epidemiologia , Brasil/epidemiologia , Portador Sadio/microbiologia , Infecção Hospitalar/microbiologia , Genes Bacterianos , Genótipo , Hospitais de Ensino , Humanos , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Tipagem Molecular , Mucosa Nasal/microbiologia , Infecções Estafilocócicas/microbiologia , Fatores de Virulência/genéticaRESUMO
Nasal carriage is an important reservoir of oxacillin-resistant Staphylococcus aureus (ORSA). Mupirocin is a topical drug used to remove S. aureus from nares. However, isolates resistant to mupirocin have been reported all over the world. Silver sulphadiazine (SSD) is a topical agent, which when associated with cerium nitrate (CN), has been shown to be useful in the treatment of burn infections and could be an alternative drug for patient decolonization. Susceptibility to oxacillin in 203 S. aureus isolates was evaluated by the agar diffusion test, while the agar diffusion and agar dilution methods were used for mupirocin. A PCR-multiplex method was performed to detect the mecA and ileS-2 genes. Minimum inhibitory concentration (MICs) to SSD and CN, used alone or in association, were determined by the agar dilution method. One hundred and sixty-three (80.3%) strains were oxacillin-resistant, and 37 (18.2%) were mupirocin resistant. The MIC of SSD alone or in association with CN was 64 microg/mL, while for CN alone was 2048 microg/mL for all isolates. SSD presented anti-staphylococcal activity at concentrations (64 microg/mL) much lower than those commonly used in commercial preparations (10 mg/g) and had good activity against mupirocin-resistant strains, showing that this drug could be used for nasal decolonization in ORSA carries.