The ability of rifampin‐resistant Escherichia coli to colonize the mouse intestine is enhanced by the presence of a plasmid‐encoded aerobactin‐iron(III) uptake system

Rifampin‐resistant Escherichia coli are known to be poor colonizers of the animal intestine. In this report, we show that the colonizing ability of rifampin‐resistant E. coli cells is increased dramatically in the presence of the aerobactin‐mediated iron(III) uptake system. In contrast, the colonization by nalidixic acid‐resistant E. coli does neither depend on the aerobactin‐iron(III) nor on the dicitrate‐iron(III) uptake system. Likewise, it does not depend on the production of the siderophore enterochelin.