In vitro activities of LTX-109, a synthetic antimicrobial peptide, against methicillin-resistant, vancomycin-intermediate, vancomycin-resistant, daptomycin-nonsusceptible, and linezolid-nonsusceptible Staphylococcus aureus

Antimicrob Agents Chemother. 2012 Aug;56(8):4478-82. doi: 10.1128/AAC.00194-12. Epub 2012 May 14.

Abstract

LTX-109 and eight other antimicrobial agents were evaluated against 155 methicillin-resistant Staphylococcus aureus (MRSA) isolates, including strains resistant to vancomycin and strains with decreased susceptibility to daptomycin and linezolid, by microdilution tests to determine MICs. Time-kill assays were performed against representative MRSA, vancomycin-intermediate S. aureus (VISA), and vancomycin-resistant S. aureus (VRSA) isolates. LTX-109 demonstrated a MIC range of 2 to 4 μg/ml and dose-dependent rapid bactericidal activity against S. aureus. This activity was not influenced by resistance to other antistaphylococcal agents.

MeSH terms

  • Acetamides / pharmacology
  • Anti-Bacterial Agents / pharmacology*
  • Daptomycin / pharmacology
  • Drug Resistance, Multiple, Bacterial
  • Linezolid
  • Methicillin / pharmacology
  • Methicillin-Resistant Staphylococcus aureus / drug effects*
  • Microbial Sensitivity Tests
  • Oligopeptides / pharmacology*
  • Oxazolidinones / pharmacology
  • Vancomycin / pharmacology
  • Vancomycin Resistance

Substances

  • Acetamides
  • Anti-Bacterial Agents
  • Oligopeptides
  • Oxazolidinones
  • Vancomycin
  • L-arginyl-2,5,7-tris(1,1-dimethylethyl)-L-tryptophyl-N-(2-phenylethyl)-L-argininamide
  • Linezolid
  • Daptomycin
  • Methicillin