In vitro activity of daptomycin and vancomycin lock solutions on staphylococcal biofilms in a central venous catheter model

Nephrol Dial Transplant. 2007 Aug;22(8):2239-46. doi: 10.1093/ndt/gfm141. Epub 2007 Apr 1.


Background: Catheter lock solutions are used for prevention and management of catheter-related bloodstream infections. We investigated the activity of daptomycin and vancomycin lock solutions against Staphylococcus aureus and Staphylococcus epidermidis in an in vitro central venous catheter (CVC) model.

Methods: Biofilm-producing reference strains of S. aureus and S. epidermidis were evaluated. After 24 h of bacterial growth in a CVC model, daptomycin and vancomycin bactericidal activity (+/- preservative-containing heparin sodium) were separately evaluated as a lock solution using 0.5, 1 and 35 mg/ml. Calcium carbonate (50 mg/l) was added to all lock solutions containing daptomycin. Each CVC was drained, flushed and sonicated at 72 h to assess CFU/ml.

Results: After 72 h of exposure in the catheter lock solutions, daptomycin and vancomycin at 0.5, 1 and 5 mg/ml demonstrated bactericidal activity (>3.0 log10 CFU/ml) against S. aureus and S. epidermidis (P <or= 0.001). Heparin lock solution alone produced a non-significant reduction in S. aureus and S. epidermidis (1.92 +/- 0.07 and 1.65 +/- 0.03 log10 CFU/ml, respectively). Daptomycin 5 mg/ml lock solution +/- heparin eradicated (limit of detection 2.0 log10 CFU/ml) S. epidermidis at 72 h as did the vancomycin 5 mg/ml plus heparin. S. aureus was only eradicated from the daptomycin 5 mg/ml catheter lock-solution.

Conclusions: Our CVC model demonstrated that 72 h of exposure to 5 mg/ml lock solutions of daptomycin (plus calcium), +/- heparin or 5 mg/ml of vancomycin plus heparin demonstrate promise in treating catheter infections with biofilm-producing S. epidermidis. Similarly, 5 mg/ml of daptomycin (plus calcium) as a lock solution shows great promise in treating S. aureus catheter infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Biofilms
  • Calcium Carbonate / pharmacology
  • Catheterization, Central Venous / instrumentation*
  • Daptomycin / pharmacology*
  • Equipment Contamination*
  • Equipment Failure
  • Reference Values
  • Staphylococcus aureus / metabolism
  • Staphylococcus epidermidis / metabolism
  • Sterilization
  • Time Factors
  • Vancomycin / pharmacology*


  • Anti-Bacterial Agents
  • Vancomycin
  • Calcium Carbonate
  • Daptomycin