Bacterial iron homeostasis and acquisition pathways

Bacterial iron homeostasis and acquisition pathways are essential systems used by pathogenic bacteria to scavenge iron from the host environment, where free iron is extremely limited due to sequestration by proteins like transferrin and lactoferrin. These pathways involve the synthesis and secretion of high-affinity iron-chelating molecules called siderophores, as well as specialized transporters for heme and inorganic iron. Because iron is a critical cofactor for numerous metabolic enzymes and DNA synthesis, disrupting these acquisition mechanisms or the regulatory Ferric Uptake Regulator (Fur) protein can significantly impair bacterial growth and virulence. In drug development, these pathways are exploited through the Trojan horse strategy, where antibiotics are conjugated to siderophores to facilitate active transport into the bacterial cytoplasm, or through the use of iron mimics like gallium that disrupt iron-dependent processes. This target area is particularly relevant for treating multi-drug resistant Gram-negative infections where traditional antibiotic entry is restricted by the outer membrane.

Other names

Bacterial iron transport systemsSiderophore-mediated iron uptakeHeme acquisition systemsFerric uptake regulator (Fur) systemTonB-dependent transport system

Drugs targeting these pathways typically function by either mimicking iron to compete for transport (e.g., gallium), utilizing iron transporters to shuttle antibiotics into the cell (Trojan horse strategy like Cefiderocol), or inhibiting the synthesis and secretion of siderophores to starve the bacteria of essential iron.