THE EFFECT OF CRANBERRY JUICE AND CRANBERRY DERIVATIVES ON THE HEMAGGLUTINATION ACTIVITY OF P-FIMBRIATED ESCHERICHIA COLI The Effect of Cranberry Juice and Cranberry Derivatives on the Hemagglutination Activity of P-Fimbriated Escherichia coli

Escherichia coli is the most common cause of urinary tract infections, especially those strains with hair-like fimbriae that aid in adhesion to the urinary tract. Binding to the epithelial cells lining the urinary tract is the first step in such an infection. A class of compounds found in cranberries called proanthocyanidins has been shown to inhibit P-fimbriated E. coli from binding to uroepithelial cells. P-fimbriated strains of E. coli have been shown to agglutinate human erythrocytes via Pfimbriae in the same manner they bind uroepithelial cells. Hemagglutination (HA) inhibition therefore correlates with a substance’s ability to block P-fimbriae mediated uroepithelial cell binding. The goal of this project was to determine the ability of cranberry juice and various other cranberry products to inhibit P-fimbriated E. coli from binding to human erythrocytes as measured by HA. The results of this study demonstrate that cranberry juice can block P-fimbriae mediated binding of E. coli to human cells when incorporated into the bacterial growth media and also directly interferes with P-fimbriae binding to their ligand. Comparison of cranberry products revealed significant differences among individual products to block P-fimbriae mediated host cell binding. Preincubation of the bacteria with the cranberry products revealed further differences in their ability to inhibit HA in a time-dependent manner.