Trace antibiotics perturb the metabolism of Escherichia coli

Since their initial clinical implementation,antibiotics have become one of the foundations of modern medicine.Antibiotics used in humans and animals are excreted through urine and feces[1],which enter the surface water or groundwater,where they eventually contaminate the water supply system.Trace levels of antibiotics,usually at nanogram per liter,have been reported in both tap and bottled water[2,3]and these compounds are often difficult to be completely removed,even after the advanced purifi-cation provided by high-end laboratory systems[4].Thus experi-mental reagents and materials might be contaminated when produced using water with trace antibiotic contamination.