title: Daptomycin is effective as antibiotic-lock therapy in a model of Staphylococcus aureus catheter-related infection.
abstract: BACKGROUND
  The effectiveness of daptomycin versus vancomycin for treating experimental methicillin-susceptible (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) catheter-related infection by antibiotic-lock technique was assessed.
  
  
  METHODS
  One MSSA strain and one clinical MRSA isolate were used. A preliminary in vitro study determined the minimum biofilm eradication concentration (MBEC) of vancomycin and daptomycin. An intravenous catheter was implanted in New Zealand white rabbits. Infection was induced by 24 h locking the catheter with 0.3 mL of broth culture containing MSSA or MRSA. The 24 h of antibiotic-lock treatment groups were: control, vancomycin 10 mg/mL, daptomycin 5 mg/mL and daptomycin 50 mg/mL.
  
  
  RESULTS
  Daptomycin showed greater in vitro activity than vancomycin against biofilm bacteria (MBECs of vancomycin and daptomycin for MSSA, >2000 mg/L and 7 mg/L; MRSA, >2000 mg/L and 15 mg/L). Daptomycin 5 mg/mL achieved significant reductions relative to vancomycin 10 mg/mL in log10 cfu recovered from catheter tips for both strains (P < 0.05). Only daptomycin 50 mg/mL achieved negative catheter tip cultures (up to 75% in MSSA and 85% in MRSA, P < 0.05), showing the greatest median log10 cfu reduction compared to controls (6.07 in MSSA and 6.59 in MRSA, P < 0.05).
  
  
  CONCLUSIONS
  Daptomycin 50 mg/mL showed the highest activity against both strains biofilms.
authors.affiliation: Infectious Diseases Research Laboratory, Infectious Diseases Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Meije
authors.affiliation: Infectious Diseases Research Laboratory, Infectious Diseases Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
authors.forename: Benito
authors.initials: B
authors.lastname: Almirante
authors.affiliation: Infectious Disease Division, Internal Medicine Department, Clínica Universitaria de Navarra, Navarra, Spain.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Del Pozo
authors.affiliation: Microbiology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Martín
authors.affiliation: Infectious Diseases Research Laboratory, Infectious Diseases Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Fernández-Hidalgo
authors.affiliation: Microbiology Department, Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: Adriana
authors.initials: A
authors.lastname: Shan
authors.affiliation: Infectious Diseases Research Laboratory, Infectious Diseases Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
authors.forename: Jana
authors.initials: J
authors.lastname: Basas
authors.affiliation: Infectious Diseases Research Laboratory, Infectious Diseases Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Pahissa
authors.affiliation: Infectious Diseases Research Laboratory, Infectious Diseases Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain. Electronic address: joan.gavalda@vhir.org.
authors.forename: Joan
authors.initials: J
authors.lastname: Gavaldà
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D019072:Antibiotic Prophylaxis / Q000379:methods*; D018441:Biofilms / Q000187:drug effects*; D055499:Catheter-Related Infections / Q000517:prevention & control*; D017576:Daptomycin / Q000008:administration & dosage*; D004195:Disease Models, Animal; D011817:Rabbits; D013203:Staphylococcal Infections / Q000517:prevention & control*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology; D014640:Vancomycin / Q000008:administration & dosage
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin; D017576:Daptomycin
keywords: Antibiotic-lock therapy; Catheter related bloodstream infection; Catheter-related infection; Daptomycin; S. aureus biofilm; Staphylococcus aureus; Vancomycin