This work seeks to generate new knowledge about the mechanisms underlying the protective effects of cranberry against urinary tract infections (UTI). Using Caco-2 cells grown in Transwell inserts as an intestinal barrier model, we found that a cranberry-derived digestive fluid (containing 135 ± 5 mg of phenolic compounds/L) increased transepithelial electrical resistance with respect to control (ΔTEER = 54.5 Ω cm²) and decreased FITC-dextran paracellular transport by about 30%, which was related to the upregulation of the gene expression of tight junction (TJ) proteins (i.e., occludin, zonula occludens-1 [ZO-1], and claudin-2) (∼3–4-fold change with respect to control for claudin-2 and ∼2–3-fold for occludin and ZO-1). Similar protective effects, albeit to a lesser extent, were observed when Caco-2 cells were previously infected with uropathogenic Escherichia coli (UPEC). In a urinary barrier model comprising T24 cells grown in Transwell inserts and either noninfected or UPEC-infected, treatments with the cranberry-derived phenolic metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and phenylacetic acid (PAA) (250 μM) also promoted favorable changes in barrier integrity and permeability. In this line, incubation of noninfected T24 cells with these metabolites induced positive regulatory effects on claudin-2 and ZO-1 expression (∼3.5- and ∼2-fold change with respect to control for DOPAC and ∼1.5- and >2-fold change with respect to control for PAA, respectively). Overall, these results suggest that the protective action of cranberry polyphenols against UTI might involve molecular mechanisms related to the integrity and functionality of the urothelium and intestinal epithelium.

Background: Urinary tract infection (UTI) prevention benefits of cranberry intake are clinically validated, especially for women and children. To ensure the benefits of cranberry dietary supplement products, the anti-adhesion activity (AAA) against uropathogenic bacteria is routinely used in in vitro bioassays to determine the activity in whole product formulations, isolated compounds, and ex vivo bioassays to assess urinary activity following intake. D-mannose is another dietary supplement taken for UTI prevention, based on the anti-adhesion mechanism.

Objective: Compare the relative AAA of cranberry and D-mannose dietary supplements against the most important bacterial types contributing to the pathogenesis of UTI and consider how certain components potentially induce in vivo activity.

Methods: The current study used a crossover design to determine ex vivo AAA against both P- and Type 1-fimbriated uropathogenic Escherichia coli of either D-mannose or a cranberry fruit juice dry extract product containing 36 mg of soluble proanthocyanidins (PACs), using bioassays that measure urinary activity following consumption. AAA of extracted cranberry compound fractions and D-mannose were compared in vitro and potential induction mechanisms of urinary AAA explored.

Results: The cranberry dietary supplement exhibited both P-type and Type 1 in vitro and ex vivo AAA, while D-mannose only prevented Type 1 adhesion. Cranberry also demonstrated more robust and consistent ex vivo urinary AAA than D-mannose over each 1-week study period at different urine collection time points. The means by which the compounds with in vitro activity in each supplement product could potentially induce the AAA in urines was discussed relative to the data.

Conclusions: Results of the current study provide consumers and healthcare professionals with additional details on the compounds and mechanisms involved in the positive, broad-spectrum AAA of cranberry against both E. coli bacterial types most important in UTIs and uncovers limitations on AAA and effectiveness of D-mannose compared to cranberry.

Adhesion of P-type and type-1 fimbriated uropathogenic E. coli (UPEC) to uroepithelial cells initiates urinary tract infections (UTIs). This research aimed to evaluate the capacities of selected cranberry polyphenols and their microbial metabolites to inhibit such adhesion in vitro using a modified fluorometric method. Data showed that the inhibition capacity of myricetin increased with concentration and plateaued at 70%. It had IC50 values of 13.2 M against P-type E. coli and 5.50 M against type-1 E. coli. Quercetin showed similar anti-adhesion capacities to myricetin. Procyanidin A2 and B2 had weaker anti-adhesion activities than myricetin and quercetin, with maximal inhibition capacities of 20%-30% against UPEC. Hippuric acid, a major metabolite of cranberry polyphenols in human urine, showed a maximal inhibition of 20% at 558 M against type-1 E. coli adhesion, whereas no anti-adhesion activity against P-type E. coli was detected. The fractions of cranberry fruit powder enriched with proanthocyanidin polymers showed the highest anti-adhesion activities compared to the fractions enriched with anthocyanins, flavonols, or proanthocyanidin oligomers. Overall, the anti-adhesion activities of cranberry polyphenols and metabolites depend on their structures and the types of fimbriae on E. coli.

Uropathogenic Escherichia coli (UPEC) are the primary cause of recurrent urinary tract infections (UTI). The poor understanding of UPEC ecology-pathophysiology from its reservoir-the gut, to its infection site-the urothelium, partly explains the inadequate and abusive use of antibiotics to treat UTI, which leads to a dramatic upsurge in antibiotic-resistance cases.Uropathogenic Escherichia coli (UPEC) ecology-pathophysiology from the gut reservoir to its urothelium infection site is poorly understood, resulting in equivocal benefits in the use of cranberry as prophylaxis against urinary tract infections. To add further understanding from the previous findings on PAC antiadhesive properties against UPEC, we assessed in this study the effects of proanthocyanidins (PAC) rich cranberry extract microbial metabolites on UTI89 virulence and fitness in contrasting ecological UPEC's environments. For this purpose, we developed an original model combining a colonic fermentation system (SHIME) with a dialysis cassette device enclosing UPEC and a 3D tissue-engineered urothelium. Two healthy fecal donors inoculated the colons. Dialysis cassettes containing 7log(10) CFU/mL UTI89 were immersed for 2h in the SHIME colons to assess the effect of untreated (7-day control diet)/treated (14-day PAC-rich extract) metabolomes on UPEC behavior. Engineered urothelium were then infected with dialysates containing UPEC for 6 h. This work demonstrated for the first time that in the control fecal microbiota condition without added PAC, the UPEC virulence genes were activated upstream the infection site, in the gut. However, PAC microbial-derived cranberry metabolites displayed a remarkable propensity to blunt activation of genes encoding toxin, adhesin/invasins in the gut and on the urothelium, in a donor-dependent manner. Variability in subjects' gut microbiota and ensuing contrasting cranberry PAC metabolism affects UPEC virulence and should be taken into consideration when designing cranberry efficacy clinical trials. IMPORTANCE Uropathogenic Escherichia coli (UPEC) are the primary cause of recurrent urinary tract infections (UTI). The poor understanding of UPEC ecology-pathophysiology from its reservoir-the gut, to its infection site-the urothelium, partly explains the inadequate and abusive use of antibiotics to treat UTI, which leads to a dramatic upsurge in antibiotic-resistance cases. In this context, we evaluated the effect of a cranberry proanthocyanidins (PAC)-rich extract on the UPEC survival and virulence in a bipartite model of a gut microbial environment and a 3D urothelium model. We demonstrated that PAC-rich cranberry extract microbial metabolites significantly blunt activation of UPEC virulence genes at an early stage in the gut reservoir. We also showed that altered virulence in the gut affects infectivity on the urothelium in a microbiota-dependent manner. Among the possible mechanisms, we surmise that specific microbial PAC metabolites may attenuate UPEC virulence, thereby explaining the preventative, yet contentious properties of cranberry against UTI.

AIM: To assess the antimicrobial effects of natural and semi-natural mouthrinses on isolates of Streptococcus mutans, Lactobacillus fermentum, and Lactobacillus casei obtained from the saliva samples and their reference strains. MATERIALS AND METHODS: Natural and semi-natural mouthrinses included in this study were herbal mix mouthrinse, cranberry mouthrinse, chlorhexidine digluconate mouthrinse, cranberry extract mixed with chlorhexidine digluconate mouthrinse, chlorhexidine digluconate mouthrinse with alcohol (positive control), and distilled water (negative control). The microbiological examination tests were minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and zone of inhibition test for the saliva isolates of S. mutans, L. fermentum, and L. casei while zone of inhibition test only for their reference strains. RESULT: Compared with distilled water, herbal mix, cranberry, cranberry mixed with chlorhexidine, chlorhexidine with alcohol (+), and chlorhexidine mouthrinses were associated with a significant increase of the zone of inhibition 34.354, 34.255, 34.219, 10.801, and 9.386, respectively. Both MIC and MBC were significantly higher in the cranberry mixed with chlorhexidine than in chlorhexidine with alcohol. The MIC and MBC of mouthrinses were significantly lower in the S. mutans and L. fermentum than in L. casei. CONCLUSION: Herbal mix and cranberry mouthrinses could be effective natural alternative to chlorhexidine mouthrinse with or without alcohol in improving oral health. CLINICAL SIGNIFICANCE: Different mouthrinses proposed in this study showed antimicrobial effects against the tested oral pathogens, and possibly the tested mouthrinses will lead for future formulation of natural or semi-natural pharmaceutical mouthrinses.

Cranberry (Vaccinium macrocarpon) fruits are known for their high polyphenolics content making them a rich source of antioxidants. These polyphenolics have been reported to promote human health and are gaining attention for their antimicrobial activities against foodborne pathogens. We investigated the antimicrobial activity of an ethanolic extract (#FC111-1) prepared from cranberry pomace against Listeria spp. Many polyphenolics were identified in this extract which could be responsible for growth-inhibitory effects against 12 Listeria strains including L. monocytogenes. The minimum inhibitory concentration (MIC) of #FC111-1 determined in cation adjusted Muller Hinton broth (CAMHB) was approximately 2 mg/mL for 11 (91.7%) of these strains. The inclusion of 2-8 mg/mL (1-4 x MIC) of #FC111-1 decreased (>3 log10) viable bacterial cells of all Listeria strains in CAMHB over a 24 h period, while dose-dependently reducing bacterial salt tolerance, bacterial bile-salt hydrolase activity, bacterial biofilm formation capacity, and increasing cell-membrane permeability. The #FC111-1 extract (0.4 and 0.8% concentrations) had no effect on L. monocytogenes survival in a cooked chicken-breast meat model, highlighting the influence of protein-rich matrices on antibacterial activity and the need to consider the role of food composition when using extracts or polyphenolics from cranberry fruits to improve food-safety

The worrying rise in antibiotic resistances emphasizes the need to seek new approaches for treating and preventing periodontal diseases. The purpose of this study was to evaluate the antibacterial and anti-biofilm activity of cranberry in a validated in vitro biofilm model. After chemical characterization of a selected phenolic-rich cranberry extract, its values for minimum inhibitory concentration and minimum bactericidal concentration were calculated for the six bacteria forming the biofilm (Streptococcus oralis, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans). Antibacterial activity of the cranberry extract in the formed biofilm was evaluated by assessing the reduction in bacteria viability, using quantitative polymerase chain reaction (qPCR) combined with propidium monoazide (PMA), and by confocal laser scanning microscopy (CLSM), and anti-biofilm activity by studying the inhibition of the incorporation of different bacteria species in biofilms formed in the presence of the cranberry extract, using qPCR and CLSM. In planktonic state, bacteria viability was significantly reduced by cranberry (p < 0.05). When growing in biofilms, a significant effect was observed against initial and early colonizers (S. oralis (p 0.017), A. naeslundii (p = 0.006) and V. parvula (p = 0.010)) after 30 or 60 s of exposure, while no significant effects were detected against periodontal pathogens (F. nucleatum, P. gingivalis or A. actinomycetemcomitans (p > 0.05)). Conversely, cranberry significantly (p < 0.001 in all cases) interfered with the incorporation of five of the six bacteria species during the development of 6 h-biofilms, including P. gingivalis, A. actinomycetemcomitans, and F. nucleatum. It was concluded that cranberry had a moderate antibacterial effect against periodontal pathogens in biofilms, but relevant anti-biofilm properties, by affecting bacteria adhesion in the first 6 h of development of biofilms

In the present study, unfermented and fermented cranberry juice in combination with the Antibiotics vancomycin and tigecycline were tested for their antimicrobial activity. Cranberry juice was fermented with a recently isolated potentially probiotic Lactobacillus paracasei K5. The tested strains selected for this purpose were Enterococcus faecalis, E. faecium, Enterobacter cloacae and Staphylococcus aureus. The methods followed were the determination of zones inhibition, Minimum Inhibitory Concentration (MIC) and Fractional Inhibitory Concentration Index (FICI). Tigecycline together with fermented juice exhibited larger Zones of Inhibition (ZOI) in strains of E. faecium (65 +/- 4.8 mm) compared to the respective ZOI with tigecycline and unfermented juice (no zone). The same outcome was also obtained with E. cloacae. Vancomycin together with fermented juice exhibited larger ZOI in strains of E. faecium (28 +/- 2.2 mm) compared to the respective ZOI with vancomycin and unfermented juice (24 +/- 2.3 mm). The lowest MIC values were recorded when tigecycline was combined with fermented cranberry juice against S. aureus strains, followed by the same combination of juice and antibiotic against E. cloacae strains. FICI revealed synergistic effects between fermented juice and tigecycline against a strain of E. faecium (A2020) and a strain of E. faecalis (A1940). Such effects were also observed in the case of fermented juice in combination with vancomycin against a strain of S. aureus (S18), as well as between fermented juice and tigecycline against E. cloacae (E1005 and E1007) strains. The results indicate that the antibacterial activity of juice fermented with the potentially probiotic L. paracasei K5 may be due to synergistic effects between some end fermentation products and the antibiotic agents examined.

Cranberry has been widely utilized as a popular botanical dietary supplement to prevent urinary tract infection. The study aims to evaluate the enhanced bactericidal activities of cranberry against uropathogenic Escherichia coli (UPEC) by adding a small quantity of naturally derived antimicrobials. The antibacterial effect was examined with cranberry extract alone (15 and 20%), three kinds of medium-chain fatty acids alone (caprylic, capric, and lauric acid; 0.05–1.0 mM), essential oils alone (carvacrol and thymol; 0.5–1.0 mM), and cranberry extract containing medium-chain fatty acids or essential oils at 37 °C for 1 min. The survivors were remarkably reduced with cranberry extract containing any of the antimicrobials. For example, cranberry extract (15 and 20%) with 1.0 mM of each caprylic acid, lauric acid, and carvacrol resulted in the complete eradication of UPEC (7.55 log reduction). Flow cytometry analysis of UPEC cells exposed to combined treatment showed clear membrane disruption and cell death (>95% of damage). Adding antimicrobials to cranberry extract did not affect (P > 0.05) the characteristics of the cranberry extract (Color, °Brix, pH). The present method may be more acceptable to consumers, who tend to avoid products containing synthetic chemicals and prefer the use of natural agents.

OBJECTIVE: To investigate the effect of cranberry extracts on saliva-derived polymicrobial biofilms with regards to biofilm biomass, acidogenicity, exopolysaccharide (EPS)/microbial biovolumes, colony forming unit (CFU) counts, and the relative abundance of specific caries- and health-associated bacteria.METHODS: Saliva-derived polymicrobial biofilms were grown for 96 h in a cariogenic environment and treated for 2 min every 12 h over the entire biofilm growth period with 500 mug/mL cranberry extract or vehicle control. The effect of the cranberry extract on biofilm behaviour was evaluated using different assays and its influence on key cariogenic and health-associated bacterial populations was assessed with a microarray real-time quantitative PCR method.RESULTS: Cranberry-treated biofilms showed significant drops in biomass (38% reduction, P < 0.001), acidogenicity (44% reduction, P < 0.001), EPS/microbial biovolume ratios (P = 0.033), and CFU counts (51% reduction, P = 0.001). Furthermore, the cranberry extracts effected a significantly lower relative abundance of caries-associated Streptococcus sobrinus (fold change 0.004, P = 0.002) and Provotella denticola (0.002, P < 0.001), and a significantly higher relative abundance of the health-associated Streptococcus sanguinis (fold change 90.715, P = 0.001).CONCLUSIONS: The cranberry extract lowered biofilm biomass, acidogenicity, EPS/microbial biovolumes, CFU counts, and modulated a beneficial microbial ecological change in saliva-derived polymicrobial biofilms.