From antibiotic to peptide siderophore conjugates as modular strategies against multidrug-resistant bacteria

Area of Science:

• Microbiology
• Pharmacology
• Drug Development

Background:

• Multidrug-resistant (MDR) bacterial infections pose a significant global health threat, outpacing current antibiotic innovation.
• Conventional antibiotics are limited, and the drug pipeline struggles to keep pace with emerging resistance.
• Peptide-based antimicrobials and siderophore conjugates are investigated as next-generation solutions.

Purpose of the Study:

• Critically examine the translational viability of peptide antimicrobials and siderophore conjugates against MDR pathogens.
• Dissect structural assumptions and identify clinical blind spots hindering their success.
• Propose a paradigm shift towards more biologically and pharmacologically grounded strategies.

Main Methods:

• Review of existing literature on peptide antimicrobials and siderophore conjugates.
• Analysis of mechanistic promises versus clinical limitations.
• Examination of factors affecting efficacy, such as host proteolysis, bioavailability, and bacterial receptor expression.

Main Results:

• Peptides demonstrate potential but are limited by host proteolysis, poor bioavailability, and tissue penetration.
• Siderophore conjugates rely on variable bacterial receptors, which can be suppressed or lost.
• The failure of cefiderocol highlights the vulnerability of targeted delivery to metabolic plasticity.

Conclusions:

• Current peptide and siderophore strategies face significant clinical challenges.
• A paradigm shift is needed, moving from broad optimism to pathogen-stratified, receptor-aware, and pharmacologically sound approaches.
• Reframing these therapies within biological and clinical constraints is crucial for developing effective treatments against resistant bacteria.