In vitro activity of the synthetic lipopeptide PAL-Lys-Lys-NH(2) alone and in combination with antifungal agents against clinical isolates of Cryptococcus neoformans

Peptides. 2007 Aug;28(8):1509-13. doi: 10.1016/j.peptides.2007.07.010. Epub 2007 Jul 17.

Abstract

The in vitro activity of the lipopeptide PAL-Lys-Lys-NH(2) (PAL), alone or combined with either fluconazole (FLU) or amphotericin B (AMB), was investigated against 14 Cryptococcus neoformans isolates. PAL MICs ranged from 1.0 to 4.0 microg/ml. Fungicidal activity was observed. Synergy, defined as a fractional inhibitory concentration (FIC) index of < or =0.5, was observed in 21.4% of PAL/AMB interactions. Antagonism (FIC index>4) was never observed. The broad antifungal activity and the positive interactions with AMB suggest that PAL can represent a promising candidate in infections due to C. neoformans.

MeSH terms

  • Amphotericin B / administration & dosage
  • Antifungal Agents / administration & dosage
  • Antifungal Agents / pharmacology*
  • Antimicrobial Cationic Peptides / administration & dosage
  • Antimicrobial Cationic Peptides / pharmacology
  • Cryptococcus neoformans / drug effects*
  • Cryptococcus neoformans / isolation & purification
  • Dipeptides / administration & dosage
  • Dipeptides / pharmacology*
  • Drug Synergism
  • Fluconazole / administration & dosage
  • Humans
  • In Vitro Techniques
  • Microbial Sensitivity Tests

Substances

  • Antifungal Agents
  • Antimicrobial Cationic Peptides
  • Dipeptides
  • Amphotericin B
  • Fluconazole