Siderophore

Siderophores are low-molecular-weight, high-affinity iron-chelating compounds secreted by microorganisms, such as bacteria and fungi, to sequester ferric iron from the environment. Because iron is essential for microbial metabolism but poorly soluble and sequestered by host proteins like transferrin, siderophores are critical virulence factors that allow pathogens to thrive during an infection. In clinical pharmacology, siderophores are utilized in two primary ways: as therapeutic agents themselves to treat iron overload (e.g., deferoxamine) and as delivery vehicles for antibiotics. The latter, often referred to as the 'Trojan Horse' strategy, involves conjugating a drug to a siderophore moiety to bypass the outer membrane permeability barrier of Gram-negative bacteria, a technique exemplified by the antibiotic cefiderocol. Targeting siderophore-mediated transport systems represents a promising frontier for overcoming multi-drug resistance in pathogens like Pseudomonas aeruginosa and Acinetobacter baumannii.

Other names

Microbial iron chelatorIron-binding ligandFerriophore

Siderophores are targeted through the 'Trojan Horse' mechanism, where an antimicrobial agent is chemically conjugated to a siderophore to facilitate active transport across bacterial membranes via specific iron-uptake transporters. Additionally, exogenous siderophores act as therapeutic chelators by binding systemic ferric iron to form stable complexes that are subsequently excreted.