Iron uptake is essential for Escherichia coli survival in drinking water

Aims: The aim of this study was to elucidate if the need for iron for Escherichia coli to remain cultivable in a poorly nutritive medium such as the drinking water uses the iron transport system via the siderophores. Methods and Results: Environmental strains of E. coli (isolated from a drinking water network), referenced strains of E. coli and mutants deficient in TonB, an essential protein for iron(III) acquisition, were incubated for 3 weeks at 25 degrees C, in sterile drinking water with and without lepidocrocite (gamma-FeOOH), an insoluble iron corrosion product. Only cells with a functional iron transport system were able to survive throughout the weeks. Conclusions: The iron transport system via protein TonB plays an essential role on the survival of E. coli in a weakly nutritive medium like drinking water. Significance and Impacts of the Study: Iron is a key parameter involved in coliform persistence in drinking water distribution systems.