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Increased killing of staphylococci and streptococci by daptomycin compared with cefazolin and vancomycin in an in

Elizabeth D Hermsen1, Laurie B Hovde, John R Hotchkiss

  • 1Department of Experimental and Clinical Pharmacology, The University of Minnesota College of Pharmacy, Minneapolis, Minnesota 55455, USA.

Antimicrobial Agents and Chemotherapy
|November 26, 2003
PubMed

Insights

Daptomycin demonstrated bactericidal activity against common pathogens in peritoneal dialysis fluid (PDF), outperforming cefazolin and vancomycin. This suggests daptomycin

Area of Science:

  • Microbiology
  • Pharmacology
  • Nephrology

Background:

  • Peritoneal dialysate fluid (PDF) can inhibit antibacterial activity, posing challenges for treating infections in patients undergoing peritoneal dialysis.
  • Common pathogens in peritoneal dialysis-associated peritonitis include Staphylococcus aureus (both methicillin-resistant [MRSA] and susceptible [MSSA]) and Staphylococcus epidermidis (MSSE).
  • The efficacy of standard antibiotics like cefazolin and vancomycin may be compromised in the PDF environment.

Purpose of the Study:

  • To evaluate the in vitro antibacterial activity of daptomycin, cefazolin, and vancomycin against key pathogens in PDF.
  • To compare the efficacy of these antibiotics in PDF at different pH levels (5.5 and 7.4).
  • To determine if daptomycin is a suitable agent for treating peritoneal dialysis-associated peritonitis.

Main Methods:

  • An in vitro static model was used to expose MRSA, MSSA, MSSE, and Streptococcus sanguis to daptomycin (10, 30, 100 mg/liter), cefazolin (125 mg/liter), and vancomycin (25 mg/liter).
  • Antibiotic activity was tested in both cation-adjusted Mueller-Hinton Broth and PDF at pH 5.5 and 7.4.
  • Bactericidal and bacteriostatic effects were assessed for each antibiotic and organism combination.

Main Results:

  • Neither cefazolin nor vancomycin showed bactericidal or bacteriostatic effects against the tested organisms in PDF.
  • All tested concentrations of daptomycin exhibited bactericidal activity against all tested organisms in PDF.
  • The pH of the PDF did not influence the antibacterial activity of the tested agents.

Conclusions:

  • Daptomycin demonstrates significant bactericidal activity in PDF, unlike cefazolin and vancomycin.
  • Daptomycin shows promise as an effective agent for treating peritoneal dialysis-associated peritonitis.
  • Daptomycin offers a potential therapeutic advantage due to its potent bacterial kill rate and extent in the PDF environment.

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