FIG 3 .

Prevention of quiescence by human urine and amino acids. Glucose (0.2%) plates were seeded with 10⁵ CFU of E. coli CFT073, and 5-µl amounts of the following mixtures were spotted onto the plates: (A) 50-fold-concentrated E. coli MG1655 culture supernatant; (B) amino acid cocktail mimicking the amino acid concentrations in the 50-fold-concentrated E. coli MG1655 culture supernatant; (C) human urine; (D) amino acid cocktail mimicking the amino acid concentrations in human urine (Table 3); (E) lysine, methionine, and tyrosine (1.0 mM each); (F) lysine and methionine (1.0 mM each); (G) lysine and tyrosine (1.0 mM each); and (H) methionine and tyrosine (1.0 mM each). Plates were incubated at 37°C for 24 h. Although not shown, the results for E. coli Nissle 1917 were essentially identical.