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.