Numerous pathogenic microorganisms secrete small molecule chelators called siderophores defined by their ability to bind extracellular ferric iron, making it bioavailable to microbes. Recently, a siderophore produced by uropathogenic Escherichia coli, yersiniabactin, was found to also bind copper ions during human infections. The ability of yersiniabactin to protect E. coli from copper toxicity...

Microcin 24 is an antimicrobial peptide secreted by uropathogenic Escherichia coli. Secretion of microcin 24 provides an antibacterial defense mechanism for E. coli. In a plasmid-based system using transformed Salmonella enterica, we found that resistance to microcin 24 could be seen in concert with a multiple-antibiotic resistance phenotype. This multidrug-resistant phenotype appeared when Sal...