The 'liaisons dangereuses' between iron and antibiotics

The decline in the rate of new antibiotic discovery is of growing concern, and new antibacterial strategies must now be explored. This review brings together research in two fields (metals in biology and antibiotics) in the hope that collaboration between scientists working in these two areas will lead to major advances in understanding and the development of new approaches to tackling microbial pathogens. Metals have been used as antiseptics for centuries. In this review, we focus on iron, an essential trace element that can nevertheless be toxic to bacteria. We review the many situations in which iron and antibiotics have combinatorial effects when used together. Understanding the molecular relationships between iron and antibiotics, from pure chemistry to gene reprogramming via biochemical competition, is important not only to increase basic knowledge, but also for the development of treatments against pathogens, with a view to optimizing antibiotic efficacy.