Iron and infection: competition between host and microbes for a precious element.

During infection microbes attack host tissues, causing damage to specific organs, sepsis or even death. For proliferation microbes desperately need iron for which they have to compete with the host. Micro-organisms have developed an abundant number of strategies to acquire iron from their specific environment and to transport the element to sites of incorporation into biologically important molecules. As part of the non-specific defence mechanisms against infection, the body modifies iron metabolism in order to make iron less available for micro-organisms. Such processes have a profound effect on the immune system and are also expressed in other forms of inflammation. Microbial iron transport systems are explored as targets for antibiotic treatment and vaccines. In particular, iron chelators, used for the treatment of iron overload may become important drugs for fighting bacterial and viral infections.