Failure of time-kill synergy studies using subinhibitory antimicrobial concentrations to predict in vivo antagonism of cephalosporin-rifampin combinations against Staphylococcus aureus.

Abstract

Results of in vitro time-kill synergy studies using subinhibitory, inhibitory, or suprainhibitory concentrations of bactericidal agents were compared with treatment outcomes of experimental infective endocarditis due to a methicillin-susceptible strain of Staphylococcus aureus. For rifampin-cephalosporin combinations, in vitro synergy testing using recommended fractions of the MIC failed to predict antagonism in vivo while concentrations above the MIC corresponded with antagonism in vivo.

• Authors: C M Brandt, M S Rouse, B M Tallan, W R Wilson, J M Steckelberg
• Journal: Antimicrobial agents and chemotherapy (Antimicrob Agents Chemother) Vol. 38 Issue 9 Pg. 2191-3 (Sep 1994) ISSN: 0066-4804 [Print] United States
• PMID: 7811044 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cephalosporins
• Gentamicins
• Nafcillin
• Cefazolin
• cefpirome
• Rifampin

Topics

• Animals
• Cefazolin (pharmacology)
• Cephalosporins (pharmacology)
• Disease Models, Animal
• Dose-Response Relationship, Drug
• Drug Synergism
• Drug Therapy, Combination (pharmacology)
• Endocarditis, Bacterial (drug therapy)
• Gentamicins (pharmacology)
• Microbial Sensitivity Tests
• Nafcillin (pharmacology)
• Predictive Value of Tests
• Rabbits
• Rifampin (pharmacology)
• Staphylococcal Infections
• Staphylococcus aureus (drug effects)
• Time Factors