Antibiotic susceptibility of urinary isolates in nursing home residents consuming cranberry capsules versus placebo
Urinary tract infection (UTI) is the most common infection
among nursing home residents, and the microorganisms pre-valent in this setting pose significant challenges for treatment. Cranberries (Vaccinium macrocarpon Aiton
) are thought to reduce UTIs; this view is supported by a placebo-controlled trial showing lower rates of bacteriuria plus pyuria with daily ingestion of 300 mL of cranberry juice cocktail (15.0% versus 28.1% in controls). However, subsequent studies of cranberries for prevention of UTI, including a large Cochrane meta-analysis, have shown mixed results. Various mechanisms of the bacteriologic effect of cranberries are postulated; however, inhibition of P fimbriaemediated adhesion of E. coli by proanthocyanidin (PAC) remains the leading theory.
We sought to compare antibiotic susceptibility and proportions of nonE. coli Enterobacteriaceae among Gram-negative urinary isolates from participants randomized to cranberry capsules compared to placebo.