Inhibitors that reduce the acquisition of antibiotic resistance
The rapid emergence of antibiotic resistance is a worldwide crisis, endangering the efficacy of antibiotic treatment. A recent article in Scientific America (December 16, 2014) highlights the importance of developing strategies for reducing antibiotic resistance and prolonging the life of current antibiotics, where they state that “The true cost of antimicrobial resistance (AMR) will be 300 million premature deaths and up to $100 trillion (£64 trillion) lost to the global economy by 2050”. The rise in antibiotic resistance has become a particular concern with the emergence of antibiotic resistant “superbugs” in the clinic, which stresses the need for strategies that prolong the lifetime of antibiotics, as the pipeline of new antibiotics is not keeping pace with the development of resistance
In our recent publication in the journal Cell Chemical Biology, we outlined a strategy to block the development of resistance and prolong the life of antibiotics. This paper describes the development and characterization of a new class of phthalocyanine-based RecA inhibitors. RecA is a recombinase that is activated during bactericidal antibiotic treatment. Activated RecA turns on the SOS response by inactivating the SOS response repressor protein LexA.
Treatment of bacteria with our RecA inhibitor reduced the ability of bactericidal antibiotics to turn on SOS response pathway (Fig. 1a). This makes bacteria more sensitive to antibiotic treatment (Fig. 1b), as well as reducing their ability to acquire antibiotic resistance mutations (Fig. 1c) and genes (Fig. 1d). RecA inhibitors are effective in Gram positive and Gram negative bacteria including two multi-drug resistance bacteria: Pseudomonas aeruginosa and Staphylococcus aureus. RecA inibitors also potentiated the activity of ciprofloxacin and reduced the development of ciprofloxacin in a neutrapenic mouse bacterial infection model (Fig. 1e).
Our study highlights the advantage of including RecA inhibitors in antibiotic therapies by demonstrating their ability to potentiate the activity of antibiotics and to block the development of antibiotic resistance, both of which will ultimately prolong antibiotic shelf life.
Kausar Alam, C. Ronald Geyer
Department of Pathology and Laboratory Medicine, University of Saskatchewan, Saskatoon, Canada
RecA Inhibitors Potentiate Antibiotic Activity and Block Evolution of Antibiotic Resistance.
Alam MK, Alhhazmi A, DeCoteau JF, Luo Y, Geyer CR
Cell Chem Biol. 2016 Mar 17