The Pseudomonas Aeruginosa Toxin L-2-amino-4-methoxy-trans-3-butenoic Acid Inhibits Growth and Induces Encystment in Acanthamoeba Castellanii

Microbes Infect. 2012 Mar;14(3):268-72. doi: 10.1016/j.micinf.2011.10.004. Epub 2011 Oct 24.

Abstract

L-2-Amino-4-methoxy-trans-3-butenoic acid (AMB) is a toxic antimetabolite produced by the opportunistic pathogen Pseudomonas aeruginosa. To evaluate its importance as a potential virulence factor, we tested the host response towards AMB using an Acanthamoeba castellanii cell model. We found that AMB (at concentrations ≥ 0.5 mM) caused amoebal encystment in salt buffer, while inhibiting amoebal growth in rich medium in a dose-dependent manner. However, no difference in amoebal plaque formation was observed on bacterial lawns of wild type and AMB-negative P. aeruginosa strains. We thereby conclude that AMB may eventually act as a virulence factor, but only at relatively high concentrations.

MeSH terms

  • Acanthamoeba castellanii / drug effects*
  • Acanthamoeba castellanii / growth & development*
  • Acanthamoeba castellanii / physiology
  • Aminobutyrates / chemistry
  • Aminobutyrates / pharmacology*
  • Bacterial Toxins / chemistry
  • Bacterial Toxins / pharmacology
  • Buffers
  • Culture Media / chemistry
  • Dose-Response Relationship, Drug
  • Glycine / analogs & derivatives
  • Glycine / chemistry
  • Microbial Viability / drug effects
  • Pseudomonas aeruginosa / chemistry*
  • Staining and Labeling
  • Trophozoites / drug effects
  • Trophozoites / growth & development
  • Trophozoites / physiology
  • Trypan Blue / chemistry
  • Virulence Factors / chemistry
  • Virulence Factors / pharmacology

Substances

  • Aminobutyrates
  • Bacterial Toxins
  • Buffers
  • Culture Media
  • Virulence Factors
  • 2-amino-4-methoxy-3-butenoic acid
  • vinylglycine
  • Trypan Blue
  • Glycine