title: [Comparative activity of daptomycin against clinical isolates of methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci].
abstract: BACKGROUND
  The objective of this study was to determine the in vitro activity of daptomycin and other agents against methicillin-resistant Staphylococcus aureus (MRSA) isolates from several sources and coagulase-negative staphylococci (CoNS) from clinically significant blood cultures.
  
  
  METHODS
  We tested a total of 1186 staphylococci isolates (755 MRSA and 431 CoNS) collected as part of a multicenter surveillance program for antimicrobial resistance (VIRA study) from 40 medical centers throughout Spain between 2001 and 2006. Broth microdilution tests were performed according to the Clinical and Laboratory Standards Institute guidelines.
  
  
  RESULTS
  Most MRSA isolates were resistant to ciprofloxacin (96%) and erythromycin (79.7%). Daptomycin yielded a MIC(50)/MIC(90) of 0.5/1microg/mL in MRSA, compared with 1/2microg/mL for linezolid, vancomycin, and teicoplanin. Daptomycin MICs were in the range of < or =0.125-2microg/mL. Only 1 MRSA strain had a reproducible daptomycin MIC of 2microg/mL. Among CoNS isolates, the MIC range for daptomycin was < or =0.125-1microg/mL. Daptomycin was equally active against oxacillin-susceptible and oxacillin-resistant strains.
  
  
  CONCLUSIONS
  Daptomycin was highly active against the staphylococci isolates studied. The activity of this agent was not affected by resistance to other antibiotics such as oxacillin, teicoplanin, linezolid, ciprofloxacin, or gentamicin. These data suggest that daptomycin may be useful for the treatment of severe infection caused by MRSA or CoNS.
authors.affiliation: Servicio de Microbiología Clínica, Hospital Clínico San Carlos, Madrid, España. jpicazo@microb.net
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Picazo
authors.forename: Carmen
authors.initials: C
authors.lastname: Betriu
authors.forename: Iciar
authors.initials: I
authors.lastname: Rodríguez-Avial
authors.forename: Esther
authors.initials: E
authors.lastname: Culebras
authors.forename: Fátima
authors.initials: F
authors.lastname: López
authors.forename: María
authors.initials: M
authors.lastname: Gómez
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016470:Bacteremia / Q000382:microbiology*; D017576:Daptomycin / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D016106:Methicillin Resistance; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D013030:Spain / Q000453:epidemiology; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013210:Staphylococcus / Q000145:classification / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000302:isolation & purification; D041162:Staphylococcus haemolyticus / Q000187:drug effects / Q000302:isolation & purification; D041181:Staphylococcus hominis / Q000187:drug effects / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D017576:Daptomycin