In-vitro activity of quinupristin/dalfopristin compared with other widely used antibiotics against strains isolated from patients with endocarditis

J Antimicrob Chemother. 1997 May;39 Suppl A:75-80. doi: 10.1093/jac/39.suppl_1.75.


The activity of quinupristin/dalfopristin was compared with that of other widely used antibiotics against 355 strains isolated from patients with endocarditis. MICs were determined by a standard agar dilution method. Quinupristin/dalfopristin was inhibitory at 1 mg/L for all coagulase-negative staphylococci (n = 36) and for the majority of Staphylococcus aureus strains (n = 87). The activity of quinupristin/dalfopristin against 186 viridans streptococci was somewhat dependent on the species, with MIC50s ranging from 0.5 to 2 mg/L, being least active against Streptococcus bovis and most active against Streptococcus gordonii and Streptococcus mitis. For the staphylococci, quinupristin/dalfopristin was as active against erythromycin-susceptible as erythromycin-resistant strains. Viridans streptococci showed a slight but significant correlation between sensitivity to erythromycin and quinupristin/dalfopristin. It is concluded that quinupristin/dalfopristin has the potential to treat serious infections such as endocarditis caused by Gram-positive cocci.

Publication types

  • Comparative Study

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Endocarditis, Bacterial / microbiology*
  • Gram-Positive Bacteria / drug effects*
  • Humans
  • Microbial Sensitivity Tests
  • Streptococcus / drug effects*
  • Virginiamycin / pharmacology*


  • Anti-Bacterial Agents
  • Virginiamycin
  • quinupristin-dalfopristin