FIG 1.

YbtPQ is required for Fe(III)-Ybt-dependent growth in UPEC. (A and B) The growth of UTI89, UTI89 ΔybtPQ, and UTI89 ΔybtPQ/pybtPQ was indistinguishable in nutrient-rich LB medium (A) and nutrient-limiting M63 minimal medium supplemented with 0.2% (vol/vol) glycerol and 10 mg ml⁻¹ niacin (B). (C) In M63 minimal medium chelated with 2 mM EDDHA, all strains show decreased growth. (D) This growth defect was rescued for UTI89 and UTI89 ΔybtPQ/pybtPQ upon addition of exogenous 1 μM Fe(III)-Ybt to the chelated medium. Results are shown as means ± SDs (n = 3).