P‐FIMBRIATED ESCHERICHIA COLI IN ADULTS WITH RENAL SCARRING AND PYELONEPHRITIS.
Authors: Jacobson Stefan H. 
Published: August 2010

The commonest organism in urinary tract infections (UTI) isEscherichia coli.PyelonephritogenicE.colistrains possess P‐fimbriae which firmly attach to uroepithelial cells by recognition of a carbohydrate structure, α‐D‐Galp‐(l‐4)–β‐D‐Galp, which is confined within all glycosphingolipids related to the human P‐blood group antigens.

Several investigators have studied virulence properties ofE.coliand host resistance in relation to UTI. Uroepithelial cells from children and women with recurrent UTI have an increased capacity to bindE.coli.In contrast to previous studies the present one deals with patients with renal scarring, who constitute the major risk group among patients with UTI. P‐fimbriae mediated binding to uroepithelial cells was studied and the risk of recurrent UTI in patients with renal scarring was determined.

Ninety per cent of theE.coliisolates from female patients with acute non‐obstructive pyelonephritis in this study possess P‐fimbriae (I). The fecalE.colicolonies obtained from these patients were P‐fimbriated in 55 % compared to 11 % of the fecalE.colicolonies from healthy controls. The P‐blood group distribution in 56 female patients with renal scarring and a history of febrile UTI was the same as in a control group of 39 healthy subjects (II). A history of recurrent and/or early infections did not increase the percentage of the P1blood group phenotype.

Forty‐nine female patients with renal scarring were prospectively investigated for the incidence of symptomatic UTI in relation to fecal colonization with P‐fimbriatedE.coli(III). Fifty‐three per cent of the patients had altogether 65 episodes of symptomatic UTI during the three‐year followup (0.036 infections per month). Eight patients (16 %) had nine attacks of acute pyelonephritis and 4/5 of the testedE.colistrains from these patients were P‐fimbriated. No relationship was demonstrated between the presence of P‐fimbriatedE.coliin the fecal flora and the development of subsequent acute pyelonephritis.

The binding of P‐fimbriatedE.colito uroepithelial cells from 19 female patients with renal scarring was studied with the fluorescence‐activated cell sorting (FACS) analysis (IV). The uroepithelial cells from the patients with renal scarring exhibited a significantly higher binding capacity (p < 0.01) than uroepithelial cells from healthy controls. Furthermore, uroepithelial cells from the patients with renal scarring and kidney insufficiency had a higher availability of P‐fimbriae receptors on their uroepithelial cells than cells obtained from patients with renal scarring and normal renal function (r = – 0.75, p < 0.001) (V). No significant correlation was found between renal function and the binding of P‐fimbriatedE.colito uroepithelial cells from patients with a renal disease of other origin than infection (polycystic kidney disease). This indicates that uremia itself was not responsible for the correlation between P‐fimbriae receptor accessibility on uroepithelial cells and kidney function.

The hypothesis is that patients with a high availability of P‐fimbriae receptors on uroepithelial cellls attract early and/or recurrent upper UTI, which in turn may lead to kidney failure.