Figure 5. Escherichelin is produced during clinical E. coli UTI and experimental human colonization with the asymptomatic bacteriuria strain E. coli HU2117.

(A) Representative LC-MS/MS chromatogram for escherichelin in urine from a patient with an uncomplicated UTI caused by a Ybt-producing UPEC strain (results from 18 urine samples are shown in Table 1). Escherichelin coeluted with the ¹³C-IS (green). Escherichelin was undetectable in urine from a patient with a UTI caused by a Ybt-nonproducing UPEC strain. (B and C) LC-MS/MS chromatograms for escherichelin in urine from subjects who were successfully (B) or unsuccessfully (C) colonized with E. coli HU2117. The days after insertion of the HU2117-coated study catheter are indicated on the left. Where microbiological culture data were available, the results are listed to the right of the chromatograms. The colonized subject (B, subject 9) was colonized with HU2117 for 57 days and then developed a febrile UTI caused by another strain of E. coli on day 76, after colonization had ended. On day 7, P. aeruginosa was also present in this subject’s urine. Escherichelin was detectable throughout the colonization period and during the symptomatic E. coli UTI. The noncolonized subject (C) did not show a presence of HU2117 after day 0, when the study catheter was inserted, and escherichelin was not detected in the longitudinal samples. P. vulgaris, Proteus vulgaris; A. faecalis, Alcaligenes faecalis; O. anthropi, Ochrobactrum anthropi; B. bronchiseptica, Bordetella bronchiseptica; S. epidermis, Staphylococcus epidermidis.