Bacteriostatic and fungostatic action of catecholamide iron chelators

Iron starvation as a means of controlling the proliferation of microorganisms was evaluated in vitro with spermidine catecholamide iron chelators. The growth of Escherichia coli and Pseudomonas aeruginosa was sensitive only to (D,L)-parabactin, whereas the growth of Candida albicans and Staphylococcus aureus was sensitive to a variety of catecholamide chelators. The disappearance of catecholamide activity upon methylation of the catechol hydroxyls, as well as iron reversal experiments, strongly suggests that the mechanism by which these compounds suppress growth is dependent upon their ability to sequester iron.