Siderophore-Mediated Iron Acquisition in Pseudomonas Aeruginosa

Pseudomonas aeruginosa is a versatile Gram-negative bacterium whose ability to thrive in iron-limiting environments underpins both its environmental adaptability and its pathogenicity in humans. Iron acquisition in this organism is largely mediated by siderophores, small iron-chelating molecules secreted to scavenge ferric iron from host proteins or environmental sources. The principal siderophores produced are pyoverdine, a high-affinity fluorescent compound, and pyochelin, a lower-affinity chelator. In addition, P. aeruginosa can appropriate xenosiderophores generated by other microbes, expanding its iron sources. Uptake of ferric-siderophore complexes is facilitated by outer-membrane TonB-dependent receptors and energised via the TonB–ExbB–ExbD system. Regulation of siderophore synthesis and transporter expression is tightly controlled by intracellular iron sensors, ensuring efficient iron homeostasis. Beyond nutrient acquisition, siderophores contribute to virulence by modulating host immune responses, mediating interbacterial competition and serving as delivery vehicles for Trojan-horse antibiotic strategies. Recent advances have illuminated the structures of transporter–siderophore complexes, revealed novel regulatory circuits in cell-surface signalling and uncovered siderophore derivatives with potent antimicrobial activities. These findings have deepened our understanding of microbial iron homeostasis and prompted the development of innovative therapeutics targeting siderophore pathways.

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Siderophore-Mediated Iron Acquisition in Pseudomonas Aeruginosa publication trend

The graph below shows the total number of articles in siderophore-mediated iron acquisition in pseudomonas aeruginosa across all publications each year (not limited to Nature Index journals).

Technical terms

Siderophore: A small, high-affinity iron-chelating compound secreted by microorganisms to acquire ferric iron from the environment or host.

Pyoverdine: The primary fluorescent siderophore of P. aeruginosa, notable for its very high affinity for ferric iron and role in virulence.

TonB-dependent receptor (TBDR): An outer-membrane protein that imports siderophore–iron complexes using energy transduced from the inner membrane.

Cell-surface signalling (CSS): A regulatory pathway in which an outer-membrane receptor acts as both transporter and signal transducer to control gene expression in response to substrate binding.

Xenosiderophore: A siderophore produced by one species that is recognised and utilised by another via dedicated uptake systems.

References

1. Antimicrobial activity of iron-depriving pyoverdines against human opportunistic pathogens. eLife (2024).
2. Bacterial TonB-dependent transducers interact with the anti-σ factor in absence of the inducing signal protecting it from proteolysis. PLOS Biology (2024).
3. Illuminating Siderophore Transporter Functionality with Thiopeptide Antibiotics. mBio (2023).
4. Mechanisms of iron homeostasis in Pseudomonas aeruginosa and emerging therapeutics directed to disrupt this vital process. Microbial Biotechnology (2023).