Peptide-conjugated phosphorodiamidate morpholino oligomer (PPMO) restores carbapenem susceptibility to NDM-1-positive pathogens in vitro and in vivo

J Antimicrob Chemother. 2017 Mar 1;72(3):782-790. doi: 10.1093/jac/dkw476.

Abstract

Objectives: The objective of this study was to test the efficacy of an inhibitor of the New Delhi metallo-β- lactamase (NDM-1). Inhibiting expression of this type of antibiotic-resistance gene has the potential to restore antibiotic susceptibility in all bacteria carrying the gene.

Methods: We have constructed a peptide-conjugated phosphorodiamidate morpholino oligomer (PPMO) that selectively inhibits the expression of NDM-1 and examined its ability to restore susceptibility to meropenem in vitro and in vivo .

Results: In vitro , the PPMO reduced the MIC of meropenem for three different genera of pathogens that express NDM-1. In a murine model of lethal E. coli sepsis, the PPMO improved survival (92%) and reduced systemic bacterial burden when given concomitantly with meropenem.

Conclusions: These data show that a PPMO can restore antibiotic susceptibility in vitro and in vivo and that the combination of PPMO and meropenem may have therapeutic potential against certain class B carbapenem-resistant infections in multiple genera of Gram-negative pathogens.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / administration & dosage
  • Anti-Bacterial Agents / pharmacology*
  • Anti-Bacterial Agents / therapeutic use
  • Bacterial Load / drug effects*
  • Drug Resistance, Multiple, Bacterial
  • Drug Therapy, Combination
  • Enterobacteriaceae / drug effects*
  • Enterobacteriaceae / enzymology
  • Enterobacteriaceae Infections / drug therapy
  • Enterobacteriaceae Infections / microbiology
  • Escherichia coli / drug effects
  • Meropenem
  • Mice
  • Microbial Sensitivity Tests
  • Morpholinos / administration & dosage
  • Morpholinos / pharmacology*
  • Morpholinos / therapeutic use
  • Sepsis / drug therapy
  • Sepsis / microbiology
  • Thienamycins / administration & dosage
  • Thienamycins / pharmacology*
  • Thienamycins / therapeutic use
  • beta-Lactamases / genetics*
  • beta-Lactamases / metabolism

Substances

  • Anti-Bacterial Agents
  • Morpholinos
  • Thienamycins
  • beta-Lactamases
  • beta-lactamase NDM-1
  • Meropenem