Escherichia coli adherence to anion exchange resin. In vitro model for initial screening of potential antiadherence agents.

The first step in developing a bladder infection is attachment of bacteria to the bladder epithelium. Removing the bladder mucin increases bacterial adherence up to a thousand-fold, and this increase can be prevented by pretreating the mucin-deficient bladder with heparin. To develop a rapid, in vitro antiadherence screening assay, we studied the adherence of Escherichia coli to various chromatography resins and the ability of heparin and other agents to antagonize this attachment. The results can be summarized as follows: Although E. coli attached to all resins, only the adherence to the anion exchange resin was inhibited by heparin (up to 95%). Agents which did not effect E. coli adherence to the resin did not affect attachment to the bladder. Agents which inhibited E. coli adherence to the bladder also inhibited E. coli adherence to the resin. Similar to the effect of heparin on E. coli attachment, the adherence of Klebsiella ozaene, Proteus mirabilis, and Streptococcus fecalis to both bladder epithelium and anion exchange resin were also antagonized. These studies indicate that the adherence of E. coli (as well as other bacterial species) to anion exchange resin responds to heparin and other chemical agents in a similar manner as does adherence to the mucin-deficient rabbit urinary bladder. Because of the ease and rapid nature of this in vitro assay, it serves as a useful screen for potential bacterial antiadherence agents and could be used to help elucidate mechanisms of bacterial attachment.