LOSS OF FIMBRIAL ADHESION WITH THE ADDITION OF VACCINUM MACROCARPON TO THE GROWTH-MEDIUM OF BETA-FIMBRIATED ESCHERICHIA-COLI

Purpose: Vaccinium macrocarpon-the American cranberry-irreversibly inh ibits the expression of P-fimbriae of E. coli. Further effects on the function and expression of P-fimbriae were studied by growing P-fimbri ated E. coli in solid media laced with cranberry juice. Methods: Cranb erry concentrate at pH 7.0 was added to CFA medium to a final concentr ation of 25%. E. coli strains JR1 and DS17 were plated on this medium with a plain CFA control and incubated at 37C. Cultures were tested fo r ability to agglutinate P-receptor specific beads. Bacteria were wash ed in PBS and agglutination retested. Cultures were also replated on p lain CFA agar and rechecked for their ability to agglutinate. Transmis sion electron micrographs were performed on positive control and test bacteria. Results: For E. coli strain JR1, P-fimbrial agglutination wa s inhibited after the third plating. DS17 was fully inhibited after th e second plating. Washing in PBS did not affect agglutination, but rep lating on CFA agar allowed agglutination to recur. Electron micrograph ic study of control populations confirmed fimbriae. Fully inhibited ba cteria had a 100% reduction in expression of fimbriae. Additionally, i nhibited bacteria showed cellular elongation. Conclusions: Cranberry j uice irreversibly inhibits P-fimbriae. Electron micrographic evidence suggests that cranberry juice acts on the cell wall preventing proper attachment of the fimbrial subunits or as a genetic control preventing the expression of normal fimbrial subunits or both.