The effect of consumption of cranberry (Vaccinium macrocarpon) on Escherichia coli adherence to feline uroepithelial cells in a blind randomised cross-over trial in cats.

Abstract

Introduction: Escherichia coli is the most common uropathogen in humans, dogs and cats. Dietary consumption of cranberry (Vaccinium macrocarpon) is known to be associated with a reduction in uropathogenic E. coli (UPEC) adhesion to human and canine urinary epithelial cell lines, but this has not been shown in cats.

Material and methods: Six neutered domestic cats, one male and five females, were randomly fed three diets successively, one containing 0.1% cranberry powder, one containing 0.3% cranberry powder, and one being the control without cranberry. Naturally emitted urine was collected on the last two days of each period of two weeks and used for bacterial growth. Adherence to Crandell-Rees feline kidney (CRFK) uroepithelial cells of the feline UPEC C571 strain (positive for the papC gene marker for P-fimbriae and the fimA marker for type 1 pili and negative for the gene of the alpha haemolysin cytotoxin hlyA, and additionally non-haemolytic in vitro on blood agar) was quantified after growth in urine samples.

Results: Significant reductions in bacterial adherence to CRFK cells were observed for 60% of cats receiving 0.1% cranberry powder supplementation and for all cats receiving 0.3% cranberry powder supplementation, compared to the same animals consuming the control diet.

Conclusion: Dietary supplementation with cranberry may provide some degree of protection to cats against adhesion of UPEC to feline uroepithelial cells.