Antimicrobial Susceptibility and Selection of Resistance Among Staphylococcus epidermidis Isolates Recovered from Patients with Infections of Indwelling Foreign Devices

摘要: Twenty-seven isolates of Staphylococcus epidermidis from patients with prosthetic valve endocarditis or infected cerebrospinal fluid shunts were examined for susceptibility to antimicrobial agents. Subpopulations resistant 20 and 100 mug methicillin per ml present in 63% the (methicillin-resistant isolates). nafcillin cephalothin found every methicillin-resistant isolate but frequencies (10(-5.0 +/- 0.5) 10(-6.4 0.9), respectively) which not always detectable by testing. Resistance >/=1.6 penicillin was 80% isolates. Cephalothin, cefazolin, cefamandole more active than cefoxitin cephradine, gentamicin tobramycin amikacin; rifampin single most agent against all There no difference between shunt infection Among isolates, phenotypic expression resistance could be enhanced 48 h incubation each drug. Isolates containing subpopulations killed methicillin, nafcillin, cephalothin. High-level emerged both methicillin-sensitive after 8 24 this The presence absence antibiotic-resistant among S. their selection during treatment should considered when therapy is devised.