Bacterial attachment and inflammation in the urinary tract.

The mechanism whereby attachment enhances Escherichia coli virulence in the urinary tract was studied by a detailed analysis of the host response to bacteriuria. Episodes of bacteriuria in 1473 children were followed prospectively from 1970 to 1984. To study the inflammatory response to the bacteriuric epidoses, we recorded body temperature, C-reactive protein, microsedimentation rate, urinary leukocyte count, and renal concentrating capacity. Bacterial isolates from each episode were identified and saved, and the adhesive capacity of 2669 E. coli strains was defined by their binding to galactose alpha 1----4galactose beta-containing receptors. Inflammatory response was significantly higher and renal concentrating capacity significantly lower during episodes caused by attaching strains. There was a linear relation between the number of indicators of inflammation and the proportion of galactose alpha 1----4galactose beta-binding strains present. Vesicoureteric reflux potentiated the inflammatory response. Attaching strains of E. coli thus appeared to be more capable of causing inflammation than were other bacteria. The potentiating effect of attachment on inflammation explains the over-representation of galactose alpha 1----4galactose beta-recognizing bacteria in patients with acute pyelonephritis.