Prevalence of antibiotic resistance among clinical isolates of methicillin-resistant staphylococci.

The prevalence of methicillin-resistant and multiply antibiotic-resistant staphylococci causing infections in hospitalized patients was studied over a two-year period. Among 122 clinically significant staphylococci, the prevalence of methicillin resistance was 66%, with a higher prevalence of Staphylococcus haemolyticus (85%) and Staphylococcus epidermidis (83%) observed than of Staphylococcus aureus (49%). Multiple antibiotic resistance was observed more frequently among coagulase-negative staphylococcus (52 to 70%) than among Staphylococcus aureus (17%). All strains of methicillin-resistant Staphylococcus aureus were susceptible to glycopeptide antibiotics and to trimethoprim-sulfamethoxazole, whereas approximately 50% of coagulase-negative staphylococci exhibited either moderate susceptibility or resistance to teicoplanin. For these latter strains, vancomycin remains the agent of choice, whereas teicoplanin cannot be recommended unless its efficacy is established by MIC determination.