Inhibition of bacterial and fungal pathogens by the orphaned drug auranofin.

Background: We identified auranofin as an antimicrobial compound utilizing a high-throughput screen using a Caenorhabditis elegans-Staphylococcus aureus infection model. Results/methodology: Treatment of infected nematodes with auranofin resulted in a prolonged survival rate of 95%, reached with 0.78 μg/ml. Further investigation of the antimicrobial activity of auranofin found inhibition against S. aureus, Enterococcus faecium and Enterococcus faecalis. Importantly, the fungal pathogens Cryptococcus neoformans was also effectively inhibited with an MIC at 0.5 μg/ml. Auranofin appears to target the thioredoxin system.
Conclusion: This work provides extensive additional data on the antibacterial effects of auranofin that includes both reference and clinical isolates and reports a novel inhibition of fungal pathogens by this compound.
Competing Interests: Financial & competing interests disclosure This research was supported by a COBRE-Immune-based intervention against infectious diseases pilot grant and a Brown University Dean's Emerging Areas of New Science award to B Burgwyn Fuchs, and a NIH P01 grant to E Mylonakis. Our work was also supported with funding provided by the Brown-Brazil Initiative awarded to B Burgwyn Fuchs and E Mylonakis. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilized in the production of this manuscript.