D. Grenier et al., Iron-chelating activity of tetracyclines and its impact on the susceptibility of Actinobacillus actinomycetemcomitans to these antibiotics, ANTIM AG CH, 44(3), 2000, pp. 763-766
Three tetracyclines (tetracycline, doxycycline, and minocycline) were found
to possess iron-chelating activity in a colorimetric siderophore assay. De
termination of MICs indicated that the activity of doxycycline against the
periodontopathogen Actinobacillus actinomycetemcomitans was only slightly i
nfluenced by the presence of an excess of iron that likely saturates the an
tibiotic. On the other hand, the MICs of doxycycline and minocycline were s
ignificantly lower for A. actinomycetemcomitans cultivated under iron-poor
conditions than under iron-rich conditions.