View photos of the medicinal plant Arctostaphylos uva-ursi (Uva-ursi), profiled in Medicinal Plants of the Western Mountain States.

A passage from Medicinal Plants of the Western Mountain States:

Another influence of Uva–ursi, apart from or at least only partly associated with hydroquinone, is its urine acidifying effect. This is important since the commonest urinary tract infection causing pathogen, Escherichia coli, is unable to successfully attach to cell walls and multiply in acidic urine.