Propolis potentiates the effect of cranberry (Vaccinium macrocarpon) in reducing the motility and the biofilm formation of uropathogenic Escherichia coli.

One strategy to prevent urinary tract infections is the use of natural products such as cranberry (Vaccinium macrocarpon) and propolis. The objective of this study was to evaluate the impact of these products alone and combined on the motility and biofilm formation of a collection of representative uropathogenic Escherichia coli (UPEC). Motility was evaluated by the swarming and swimming capacity of the isolates in presence/absence of cranberry ± propolis. Early and late biofilm formation was observed with the Biofilm Ring test (BioFilm Control) and the crystal violet method. Cranberry alone was seen to have a variable effect on motility and biofilm formation unrelated to bacterial characteristics, but a reduced motility and biofilm formation was observed for all the isolates in the presence of cranberry + propolis. These results suggest that cranberry alone doesn't work on all the E. coli strains and propolis potentiates the effect of cranberry on UPEC, representing a new strategy to prevent recurrent urinary tract infections.
Competing Interests: I have read the journal's policy and the authors of this manuscript have the following competing interests: we declare that Jeremy Ranfaing obtained a PhD fellowship from Nutrivercell. This grant corresponds to a « Bourse CIFRE », a co-funding of academic PhD (half by the University and half by the company). However in this type of grant, all the results obtained during the PhD course belongs to INSERM and University of Montpellier. Nutrivercell had/has no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This grant does not alter our adherence to PLOS ONE policies on sharing data and materials. The other authors had no financial competing interests with Nutrivercell or other commercial funder.