Antimicrobial activity of daptomycin against multidrug-resistant Gram-positive strains collected worldwide

Diagn Microbiol Infect Dis. 2004 Nov;50(3):201-4. doi: 10.1016/j.diagmicrobio.2004.07.002.


Daptomycin is a cyclic lipopeptide recently released for clinical use in the treatment of serious Gram-positive infections in hospitalized patients. We evaluated the in vitro activity of daptomycin tested against recently isolated multidrug-resistant Gram-positive clinical strains. A total of 386 isolates were selected from a large collection of strains from more than 70 centers located in Europe, North America, and South America. The strains were tested by reference broth microdilution methods in Mueller-Hinton broth with 50 mg/L Ca++ against daptomycin. Daptomycin was the most potent compound tested against penicillin-resistant Streptococcus pneumoniae with MIC50/90 values at < or =0.12 and 0.25 microg/mL, respectively. Daptomycin was also highly active against vancomycin-resistant enterococci and staphylococcal strains with various resistance patterns. Enterococcus faecium showed higher daptomycin MIC values (MIC90, 4 microg/mL) when compared to E. faecalis (MIC90, 1 microg/mL). In summary, resistance to vancomycin, teicoplanin, quinupristin/dalfopristin, or penicillin among the Gram-positive isolates did not adversely influence daptomycin activity. Daptomycin showed a significant potency and spectrum against Gram-positive species, including multidrug-resistant strains, and may represent a reasonable therapeutic option for infections caused by these important pathogens.

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Daptomycin / pharmacology*
  • Drug Resistance, Multiple, Bacterial / drug effects*
  • Global Health
  • Gram-Positive Bacteria / drug effects*
  • Gram-Positive Bacterial Infections / epidemiology
  • Gram-Positive Bacterial Infections / microbiology
  • Humans
  • Microbial Sensitivity Tests


  • Anti-Bacterial Agents
  • Daptomycin