NATHALIE TUFENKJI
McGill University

MYTH OR FACT: CAN DRINKING CRANBERRY JUICE HELP PREVENT URINARY TRACT AND OTHER INFECTIONS?

Abstract

There are more than 150 million cases of urinary tract infections (UTIs) reported globally each year with correspondingly significant morbidity and health care costs.  The standard management approach for uncomplicated UTIs is an antibiotic treatment regime; however, rising antimicrobial resistance among uropathogens has resulted in increasing clinical failure rates, emphasizing the need to develop alternate options for infection prevention and treatment. North American cranberries (Vaccinium macrocarpon) have long been considered to have protective properties against UTIs. Recent research conducted with Escherichia coli suggests that cranberries prevent UTIs by hindering bacterial attachment to surfaces via phytochemicals known as proanthocyanidins (PACs). However, the mechanisms by which cranberry derivatives impair bacterial adhesion and virulence are not well understood. Our work aims to examine the potential of exploiting cranberry bioactivity for a broader range of infection settings (e.g., cystic fibrosis lung infections, gastroenteritis) and to unveil the mechanisms involved. 

We have found that cranberry derivatives, including cranberry PACs, can block bacterial motility important for the establishment of infections. This has been demonstrated using Pseudomonas aeruginosa (cause of urinary tract, kidney and lung infections) and other organisms implicated in UTIs, including Escherichia coli and Proteus mirabilis. Accordingly, a genome-wide transcriptional analysis of an uropathogenic E. coli revealed that the gene that encodes for the flagellar filament was downregulated in the presence of cranberry PACs. Because bacterial motility plays a pivotal role in dissemination of bacteria in the urinary tract as well as other clinical settings, these findings highlight the role that cranberry consumption might play in the prevention of chronic infections. Based on the demonstrated bioactivity of cranberry, its incorporation into and release from implantable medical devices (such as catheters) may yield considerable benefits to patient health. Interestingly, cranberry-modified silicone substrates impaired the motility and spreading of the aggressive swarmer P. mirabilis. The type of bioactivity demonstrated by these hybrid materials could prove to be effective if cranberry can be incorporated in various polymeric matrices, which would be of interest for applications in the health, biomedical device and food industries. The effect of cranberry in vivo remains to be determined; but the implications of these findings are underscored by the current rising rates of bacterial antibiotic resistance as cranberry could provide a non-antimicrobial strategy to target clinical infections. 

NATHALIE TUFENKJI is Associate Professor in the Department of Chemical Engineering at McGill University where she holds the Canada Research Chair in Biocolloids and Surfaces. She earned the M.Sc. (2001) and Ph.D. (2005) degrees in Chemical and Environmental Engineering from Yale University, where she worked on particle and pathogen transport in groundwater and riverbank environments. She received the American Water Works Association Academic Achievement Award for best doctoral dissertation in the field (2006), a Fulbright Scholar Award for tenure at Harvard University (2012), and very recently, she was awarded the YWCA Woman of Distinction Award in Science and Technology (2014). Dr. Tufenkji serves as Associate Director of the Brace Center for Water Resources Management at McGill and has co-chaired several major international conferences. She also serves on the editorial boards of Environmental Science and Technology, Water Research and Colloids and Surfaces B. Dr. Tufenkji’s research group focuses on understanding the fundamental mechanisms controlling the interaction of biocolloids (viruses, bacteria and protozoa) and abiotic particles with interfaces of environmental and biomedical interest. Current research efforts are aimed at evaluating the fate and detection of microbial pathogens and engineered nanomaterials in aquatic environments and developing an improved understanding of the potential health benefits of berry and plant derivatives with a focus on bacterial infections.

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Websites of Interest

• University of Toronto
• Faculty of Applied Science & Engineering
• Department of Chemical Engineering & Applied Chemistry