Shigella spp. and pathogenic E. coli are characterized by a variety and abundance of iron transport systems. Although members of this group of bacteria are closely related genetically, they differ widely in the iron transport systems they use. This may reflect the different niches occupied by different strains and the nature of the source of iron available in a specific environment. Only the ferrous iron transporter Feo is common to all the commensals and pathogens. All members of this group produce one or more siderophore, but no single siderophore is produced by all. Other iron transport systems include heme transporters and the ferrous iron transporters Sit and Efe. With the exception of the genes for enterobactin and the Feo system, the iron transport genes in the enterics are found within pathogenicity islands or on plasmids and their presence often increases pathogenicity or colonization of niches within the host.

Further reading: Iron Uptake and Homeostasis in Microorganisms

Labels: E. coli, Iron transport systems, Iron-homeostasis, Iron-metabolism, Iron-uptake, Shigella