Intramuscularly administered peptide A3-APO is effective against carbapenem-resistant Acinetobacter baumannii in mouse models of systemic infections

Biopolymers. 2011;96(2):126-9. doi: 10.1002/bip.21443.


Most antibacterial peptides exhibit low therapeutic indices in vivo. Peptide A3-APO was shown to exhibit high potency against Escherichia coli bacteremia when added intraperitoneally. To extend the studies to systemic infections against multidrug-resistant organisms, we studied the efficacy of A3-APO in mouse models of carbapenem-resistant Acinetobacter baumannii infection. When administered either intravenously at 2.5 mg/kg or intramuscularly (im) at 5 mg/kg twice or three times to mice infected with a carbapenem-resistant A. baumannii strain, peptide A3-APO reduced the bacterial counts by at least two log10 units and increased the survival rate compared with untreated animals or mice treated with 40 mg/kg imipenem. Unlike after intraperitoneal or intravenous administration, A3-APO did not show toxic effects at 60 mg/kg dose im.

MeSH terms

  • Acinetobacter Infections / drug therapy*
  • Acinetobacter baumannii*
  • Animals
  • Anti-Bacterial Agents / pharmacology*
  • Carbapenems*
  • Disease Models, Animal
  • Drug Resistance, Bacterial / drug effects*
  • Female
  • Mice
  • Peptides / pharmacology*


  • A3-APO peptide
  • Anti-Bacterial Agents
  • Carbapenems
  • Peptides