Bacterial Adhesion as an Indicator of Renal Involvement in Bacteriuria of Pregnancy

The association of bacterial virulence with the host response to bacteriuria was evaluated in 70 pregnant women with acute pyelonephritis or bacteriuria detected at screening. Patients infected with Escherichia coli attaching to Galα1→4Galβ-containing receptors, had significantly higher levels of C-reactive protein and lower renal concentrating capacity than patients infected with strains lacking this specificity. The renal concentrating capacity ranged from 419–1151 mOsm/kg in the women with bacteriuria on screening. 5/11 women with a renal concentrating capacity ≤784 mOsm/kg were infected with Galα1→4Galβ-specific bacteria, compared to 0/16 of patients who concentrated the urine >784 mOsm/kg. According to earlier studies the risk for progression to pyelonephritis and recurrences during pregnancy was increased in bacteriuric women with a reduced renal concentrating capacity. The present study demonstrates that this risk group can be identified in part by the properties of the infecting E. coli strains.