BACKGROUND: Cranberry fruits possess many biological activities partly due to their various phenolic compounds; however the underlying modes of action are poorly understood. We studied the effect of cranberry fruit extracts on the gene expression of Staphylococcus aureus to identify specific cellular processes involved in the antibacterial action.
METHODS: Transcriptional profiles of four S. aureus strains grown in broth supplemented or not with 2 mg/ml of a commercial cranberry preparation (Nutricran90) were compared using DNA arrays to reveal gene modulations serving as markers for biological activity. Ethanol extracted pressed cakes from fresh fruits also produced various fractions and their effects on marker genes were demonstrated by qPCR. Minimal inhibitory concentrations (MICs) of the most effective cranberry fraction (FC111) were determined against multiple S. aureus strains and drug interactions with -lactam antibiotics were also evaluated. Incorporation assays with [(3)H]-radiolabeled precursors were performed to evaluate the effect of FC111 on DNA, RNA, peptidoglycan (PG) and protein biosynthesis.
RESULTS: Treatment of S. aureus with Nutricran90 or FC111 revealed a transcriptional signature typical of PG-acting antibiotics (up-regulation of genes vraR/S, murZ, lytM, pbp2, sgtB, fmt). The effect of FC111 on PG was confirmed by the marked inhibition of incorporation of D-[(3)H]alanine. The combination of -lactams and FC111 in checkerboard assays revealed a synergistic activity against S. aureus including strain MRSA COL, which showed a 512-fold drop of amoxicillin MIC in the presence of FC111 at MIC/8. Finally, a therapeutic proof of concept was established in a mouse mastitis model of infection. S. aureus-infected mammary glands were treated with amoxicillin, FC111 or a combination of both; only the combination significantly reduced bacterial counts from infected glands (P0.05) compared to the untreated mice.
CONCLUSIONS: The cranberry fraction FC111 affects PG synthesis of S. aureus and acts in synergy with -lactam antibiotics. Such a fraction easily obtained from poorly exploited press-cake residues, may find interesting applications in the agri-food sector and help reduce antibiotic usage in animal food production.

The motility of bacteria plays a key role in their colonization of surfaces during infection. Derivatives of cranberry fruit have been shown to interfere with bacterial motility. Herein, we report on the incorporation of cranberry derived materials (CDMs) into silicone substrates with the aim of impairing bacterial pathogen motility and spreading on the substrate surface. The release of CDMs from the silicone substrates when soaking in an aqueous medium was quantified for a period of 24h. Next, we showed that CDMs released from two silicone substrates remain bioactive as they downregulate the expression of the flagellin gene of two key uropathogens - Escherichia coli CFT073 and Proteus mirabilis HI4320. Furthermore, we demonstrate that CDM-modified silicone inhibits the swarming motility of P. mirabilis, an aggressive swarmer. The bioactive, CDM-modified substrates can find broad applications in the medical device and food industries where the impairment of bacterial colonization of surfaces is of paramount importance.

BACKGROUND: Periodontitis is a polymicrobial infectious disease. A novel potential chemical treatment modality may lie in bacterial anti-adhesive materials, such as cranberry juice fractions. The aim of this study is to explore the effect of high molecular weight cranberry constituent (non-dialyzable material [NDM]) on the virulence of a mixed infection with Porphyromonas gingivalis and Fusobacterium nucleatum in mice.
METHODS: In vitro, the anti-adhesive property of NDM was validated on epithelial cell culture, and inhibition of coaggregation was tested using a coaggregation assay. The in vivo effect was tested on the outcome of experimental periodontitis induced by a P. gingivalis and F. nucleatum mixed infection, and also on the local host response using the subcutaneous chamber model of infection. Phagocytosis was also tested on RAW macrophages by the use of fluorescent-labeled bacteria.
RESULTS: NDM was found to inhibit the adhesion of both species of bacteria onto epithelial cells and to inhibit coaggregation in a dose-dependent manner. NDM consumption by mice attenuated the severity of experimental periodontitis compared with a mixed infection without NDM treatment. In infected subcutaneous chambers, NDM alone reduced tumor necrosis factor-alpha (TNF-alpha) levels induced by the mixed infection. In vitro, NDM eliminated TNF-alpha expression by macrophages that were exposed to P. gingivalis and F. nucleatum, without impairing their viability. Furthermore, NDM increased the phagocytosis of P. gingivalis.
CONCLUSIONS: The results indicate that the use of NDM may hold potential protective and/or preventive modalities in periodontal disease. Underlying mechanisms for this trait may perhaps be the anti-adhesive properties of NDM or its potential effect on inflammation.

The antimicrobial properties of the American cranberry were studied against Escherichia coli O157:H7, Listeria monocytogenes, and Lactobacillus rhamnosus to determine the effects on growth inhibition, membrane permeability, and injury. Cranberry powder was separated using a C-18 Sep-Pak cartridge into sugars plus organic acids (F1), monomeric phenolics (F2), and anthocyanins plus proanthocyanidins (F3). Fraction 3 was further separated into anthocyanins (F4) and proanthocyanidins (F5) using an LH-20 Sephadex column. Each fraction was diluted in the brain heart infusion (BHI) broth to determine the minimum inhibitory/bactericidal concentrations (MIC/MBC). L. monocytogenes was the most susceptible to cranberry fraction treatment with the lowest MIC/MBC for each treatment, followed by E. coli O157:H7 and L. rhamnosus. Membrane permeability and potential was studied using LIVE/DEAD viability assay and using Bis (1, 3-dibutylbarbituric acid) trimethine oxonol (DiBAC4), respectively. L. rhamnosus demonstrated the highest permeability followed by E. coli O157:H7, and L. monocytogenes. L. rhamnosus demonstrated the highest recovery followed by E. coli O157:H7, and L. monocytogenes. Each cranberry fraction demonstrated membrane hyperpolarization at their native pH, while F2, F3, and F5 demonstrated membrane depolarization at neutral pH. With this knowledge cranberry compounds may be used to prevent maladies and potentially substitute for synthetic preservatives and antibiotics.

Cranberry A-type proanthocyanidins (PACs) have been recognized for their inhibitory activity against bacterial adhesion and biofilm-derived infections. However, the precise identification of the specific classes of degree-of-polymerization (DP) conferring PACs bioactivity remains a major challenge owing to the complex chemistry of these flavonoids. In this study, chemically characterized cranberries were used in a multistep separation and structure-determination technique to isolate A-type PAC oligomers of defined DP. The influences of PACs on the 3D architecture of biofilms and Streptococcus mutans-transcriptome responses within biofilms were investigated. Treatment regimens that simulated topical exposures experienced clinically (twice-daily, 60s each) were used over a saliva-coated hydroxyapatite biofilm model. Biofilm accumulation was impaired, while specific genes involved in the adhesion of bacteria, acid stress tolerance, and glycolysis were affected by the topical treatments (vs the vehicle-control). Genes (rmpC, mepA, sdcBB, and gbpC) associated with sucrose-dependent binding of bacteria were repressed by PACs. PACs of DP 4 and particularly DP 8 to 13 were the most effective in disrupting bacterial adhesion to glucan-coated apatitic surface (>85% inhibition vs vehicle control), and gene expression (eg rmpC). This study identified putative molecular targets of A-type cranberry PACs in S. mutans while demonstrating that PAC oligomers with a specific DP may be effective in disrupting the assembly of cariogenic biofilms.

BACKGROUND: Recurrent urinary tract infections (UTIs) increase mortality and reduce graft survival after renal transplantation. Strategies to prevent recurrent UTIs include L-methionine, cranberry juice, and antibiotics. Data on the efficacy of cranberry and L-methionine, however, are controversial in the general population; there are few data in renal transplant recipients.
METHODS: We performed a retrospective analysis of 82 transplant recipients with recurrent UTIs, who underwent prophylaxis with cranberry juice (2 x 50 mL/d, n = 39, 47.6%), or L-methionine (3 x 500 mg/d, n = 25, 30.5%), or both modalities (n = 18, 21.9%). Thirty patients without prophylaxis served as controls. We analyzed symptoms, pyuria/nitrituria, and incidence of UTI events during 1 year before versus after initiation of prophylaxis.
RESULTS: Prophylaxis highly significantly decreased the annual UTI incidence by 58.3% (P .001) in the study population with no change in the control group (P = .85); in addition, 53.7% of symptomatic patients reported relief of symptoms and pyuria/nitrituria disappeared in 42.4% of the dipstick-positive patients (P .001 each). Cranberry reduced the annual number of UTI episodes by 63.9% from 3.6 +/- 1.4 to 1.3 +/- 1.3/year (P .001) and L-methionine by 48.7% from 3.9 +/- 1.8 to 2.0 +/- 1.3/year (P .001).
CONCLUSION: Cranberry juice and L-methionine successfully reduced the incidence of UTI after renal transplantation.

Lactobacillus plantarum IFPL935 was incubated with individual monomeric flavan-3-ols and dimeric A- and B-type procyanidins to identify new metabolites and to determine the effect of compound structural features on bacterial growth and catabolism. Complex extracts rich in A-type proanthocyanidins and phenolic acids from cranberry were also tested. The results showed that L. plantarum IFPL935 exhibited higher resistance to nongalloylated monomeric flavan-3-ols, A-type dimeric procyanidins, and cranberry extract than to (−)-epicatechin-3-O-gallate and B-type dimeric procyanidins. Despite these findings, the strain was capable of rapidly degrading (−)-epicatechin-3-O-gallate, but not A- or B-type dimeric procyanidins. However, it
was able to produce large changes in the phenolic profile of the cranberry extract mainly due to the catabolism of
hydroxycinnamic and hydroxybenzoic acids. Of most relevance was the fact that L. plantarum IFPL935 cleaved the heterocyclic ring of monomeric flavan-3-ols, giving rise to 1-(3′,4′-dihydroxyphenyl)-3-(2″,4″,6″-trihydroxyphenyl)propan-2-ol, activity exhibited by only a few human intestinal bacteria.

Purpose: Proanthocyanidins found in cranberry have been reported to have in vitro and in vivo antibacterial activity. We determined the effectiveness of cranberry juice for the prevention of urinary tract infections in children.
Materials and Methods: A total of 40 children were randomized to receive daily cranberry juice with high concentrations of proanthocyanidin vs cranberry
juice with no proanthocyanidin for a 1-year period. The study was powered to detect a 30% decrease in the rate of symptomatic urinary tract infection with type I and II errors of 0.05 and 0.2, respectively. Toilet trained children up to age 18 years were eligible if they had at least 2 culture
documented nonfebrile urinary tract infections in the calendar year before enrollment. Patients with anatomical abnormalities (except for primary vesicoureteral
reflux) were excluded from study. Subjects were followed for 12 months. The participants, clinicians, outcome assessor and statistician were all blinded to treatment allocation.
Results: Of the children 39 girls and 1 boy were recruited. Mean and median patient age was 9.5 and 7 years, respectively (range 5 to 18). There were 20 patients with comparable baseline characteristics randomized to each group. After 12 months of followup the average incidence of urinary tract infection in the treatment group was 0.4 per patient per year and 1.15 in the placebo group
(p 0.045), representing a 65% reduction in the risk of urinary tract infection.
Conclusions: Cranberry juice with high concentrations of proanthocyanidin appears to be effective in the prevention of pediatric nonfebrile urinary tract infections. Further studies are required to determine the cost-effectiveness of this approach.

The effects of 13 food extracts and juices, including shellfish, fruits, and vegetables, on the binding ability of human norovirus (NoV) were examined, using P particles of human NoV GII.4 as a research surrogate. The enhancements (positive values) or reductions (negative values) of NoV P particle detection (changes in optical density at 450 nm) in the presence of different
food extracts and juices as compared with P particles diluted in phosphate-buffered saline were tested by saliva-binding, enzymelinked immunosorbent assay in triplicate. In the presence of different food extracts and juices at different concentrations, an increase or decrease of the receptor-binding ability of the NoV P particles was observed. Due to a higher specific binding and thus a higher
accumulation of the viral particles, oysters may be contaminated with human NoV more often than other shellfish species (mussel, hard clams, and razor clams). Cranberry and pomegranate juices were shown to reduce the specific binding ability of human NoV P particles. No such binding inhibition effects were observed for the other tested extracts of fresh produce (strawberry, blackberry,
blueberry, cherry tomato, spinach, romaine lettuce) or, notably, for raspberry, which has been associated with human NoV outbreaks.

The experiment consisted in assessing the effectiveness of a commercial product based on cranberry extracts (pHDReg.-Biomin LTDA) in the treatment of urinary tract infections (UTI) in sows. Were used 42 sows, with gestational ages ranging between 50 and 70 days, either suffering from UTI or not. Healthy animals were differentiated from affected animals by urinalysis and urine culture. The experiment was composed of sows with UTI that received the cranberry extract product in the diet for a period of 14 days; sows negative for UTI (negative controls) and sows positive for UTI (positive controls). The former two groups did not receive the cranberry extract product in the diet. Urine samples were collected on days zero, seven and 14 after initiation of treatment. Complete urinalysis of these samples, urine specific gravity, pH, bacterial count and bacterial isolation were performed. E. coli was the most frequent isolated agent (90.62%). The results showed that the commercial product made with cranberry extract was effective in promoting a reduction of urinary pH, but did not interfere in any other parameters observed.