Siderophore-mediated iron acquisition and modulation of host-bacterial interactions

Abstract

Iron is an essential micronutrient for most life forms including the majority of resident bacteria of the microbiota and their mammalian hosts. Bacteria have evolved numerous mechanisms to competitively acquire iron within host environments, such as the secretion of small molecules known as siderophores that can solubilize iron for bacterial use. However, siderophore biosynthesis and acquisition is not a capability equally harbored by all resident bacteria. Moreover, the structural diversity of siderophores creates variability in the susceptibility to host mechanisms that serve to counteract siderophore-mediated iron acquisition and limit bacterial growth. As a result, the differential capabilities to acquire iron among members of a complex microbial community carry important implications for the growth and function of resident bacteria. Siderophores can also directly influence host function by modulating cellular iron homeostasis, further providing a mechanism by which resident bacteria may influence their local environment at the host-microbial interface. This review will explore the putative mechanisms by which siderophore production by resident bacteria in the intestines may influence microbial community dynamics and host-bacterial interactions with important implications for pathogen- and microbiota-driven diseases including infection, inflammatory bowel diseases and colorectal cancer.

Maternal modifiers of the infant gut microbiota: metabolic consequences

“…A wide range of host immune responses are intricately linked with both systemic and cellular iron homeostasis. Perturbations to the labile iron pool have been linked with modulating various forms of innate and adaptive immune functions including proliferation, differentiation and secretion of inflammatory mediators (Ellermann and Arthur 2017). Processes associated with inflammation, including cytokine production and engagement of TLRs by microbial ligands, stimulate the production of the hormone hepcidin, which in turn modulates systemic iron homeostasis by limiting dietary iron absorption and increasing intracellular retention of iron (Drakesmith and Prentice 2012; Nemeth et al 2004a; Nemeth et al 2004b).…”

Iron overload and altered iron metabolism in ovarian cancer

“…Lipid peroxidation mediated by heme was reduced in rats treated with antibiotics, which was accompanied by decreased crypt cell proliferation (Martin et al, 2015). Siderophores enable bacteria to solubilize iron from their environment to promote their cellular proliferation (Ellermann and Arthur, 2016). For example, uropathogenic E. coli (UPEC) bacteria depend on iron for growth and the ferritinophagy pathway was recently demonstrated to contribute to its increased survival (Bauckman and Mysorekar, 2016).…”

Modified chrome azurol S method for detection and estimation of siderophores having affinity for metal ions other than iron

“…) to coordinate with the ferric ion (Neilands 1981;Neilands 1995;Miethke and Marahiel 2007;Sonawane et al 2016;Wani et al 2016;Niehus et al 2017;Ellermann and Arthur 2017). However, microorganisms also need metal ions other than Fe 3+ and in order to chelate these metal ions, they produce various other types of siderophores.…”