Buried Treasure: Evolutionary Perspectives on Microbial Iron Piracy

Host–pathogen interactions provide valuable systems for the study of evolutionary genetics and natural selection. The sequestration of essential iron has emerged as a crucial innate defense system termed nutritional immunity, leading pathogens to evolve mechanisms of ‘iron piracy’ to scavenge this metal from host proteins. This battle for iron carries numerous consequences not only for host–pathogen evolution but also microbial community interactions. Here we highlight recent and potential future areas of investigation on the evolutionary implications of microbial iron piracy in relation to molecular arms races, host range, competition, and virulence. Applying evolutionary genetic approaches to the study of microbial iron acquisition could also provide new inroads for understanding and combating infectious disease.

TrendsThe battle between microbes and their hosts for nutrient iron is emerging as a new front of evolutionary genetic conflict.Molecular arms races can emerge between host iron-binding proteins and microbial ‘iron piracy’ factors that steal this nutrient for growth. Such rapid evolution may also contribute to the host range of pathogenic microbes.Iron acquisition plays an important role in evolutionary interactions between microbes, both in the environment and within the host. Competition for iron can prevent infection by pathogens, while genetic changes in iron acquisition systems can enhance microbial virulence.Evolutionary conflicts for nutrient iron are revealing potential new genetic mechanisms of disease resistance as well as avenues for therapeutic development.