Invited Speaker Australian Society for Microbiology Annual Scientific Meeting 2018

Reversing antibiotic resistance by destabilization of bacterial metal homeostasis (#95)

Mark Walker 1
  1. The University of Queensland, St. Lucia, QLD, Australia

The World Health Organization reports that antibiotic resistant pathogens represent an imminent global health disaster for the 21st Century. Gram-positive superbugs threaten to breach last-line antibiotic treatment, and the pharmaceutical industry antibiotic development pipeline is waning. Here we report the synergy between ionophore-induced physiological stress in Gram-positive bacteria and antibiotic treatment. PBT2 is a safe-for-human-use zinc ionophore that has progressed to Phase 2 clinical trials for Alzheimer’s and Huntington’s disease treatment. In combination with zinc, PBT2 exhibits antibacterial activity and disrupts cellular homeostasis in erythromycin-resistant group A Streptococcus (GAS), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). We were unable to select for mutants resistant to PBT2+zinc treatment. While ineffective alone against resistant bacteria, several clinically relevant antibiotics act synergistically with PBT2+zinc to enhance killing of these Gram-positive pathogens. These data represent a new paradigm whereby disruption of bacterial metal homeostasis reverses antibiotic resistant phenotypes in a number of priority human bacterial pathogens.