Gentamicin- and methicillin-resistant Staphylococcus aureus: phenotypic and genotypic characterization of three putative nosocomial outbreak strains.

Nineteen representative isolates of gentamicin- and methicillin-resistant Staphylococcus aureus (MRSA) were found to comprise three phenotypes; these differed with regard to hydrolysis of nitrocefin and production of staphylococcal enterotoxin A or/and toxic shock syndrome toxin-1. All MRSA isolates produced a capsule and were susceptible to coumermycin, nitrofurantoin, novobiocin, trimethoprim, trimethoprim-sulfamethoxazole, teicoplanin and vancomycin. All MRSA isolates were resistant to co-amoxiclav, ciprofloxacin, clarithromycin, gentamicin, methicillin, norfloxacin, ofloxacin, oxacillin and polymyxin B.