Iron and bacterial virulence.

An invading pathogen must have the ability to multiply successfully within the hostile environment of the mammalian host to establish an infection. Bacterial and other pathogens produce a range of virulence determinants required for pathogenicity, many of which are regulated by environmental factors; level of iron is one of the important factors intimately connected to the synthesis of some of the virulence determinants. There is direct evidence to show that iron, in association with the iron-regulator Fur (in many gram negative organisms)/DtxR (in several gram positive organisms) operates at the molecular level and acts as a regulatory molecule, controlling not only the iron acquisition machinery but the expression of toxins and other bacterial virulence determinants, that are not related to iron metabolism.