Antimicrobial susceptibility of Staphylococcus aureus isolated from colonized hospital personnel

The present study was performed to investigate the in vitro activity of oxacillin and other antimicrobial agents against S. aureus strains obtained from nursing personnel. We tested 127 S. aureus colonizing nasal mucous and hand skin and isolated from nursing personnel of University Hospital Department of Infectious Diseases, Iaşi, during June 2005 period. Minimum inhibitory concentrations (MICs) were determined by the dilution method in Mueller-Hinton agar. Most of the S. aureus strains were susceptible to tested agents excepted erythromycin and azithromycin. Erythromycin and azithromycin resistance was observed among 29.1% respectively 22% of S. aureus strains. Vancomycin was active against all isolates. Teicoplanin was active against against all MRSA excepted one of the strain, with an reduced susceptibility. Linezolid has very good in vitro activity against staphylococci, with an MIC 90 of 2 mcg/ml and only 0.8% resistance. The MIC values range was between 0.5-2 mcg/ml. In conclusion, the usually hygienic methods (disposable gowns, hygienic hand disinfection after each patients contact, masks use when is a risk of aerosolization of MRSA) are indicate for significantly reducing of these strains.