ABSTRACT: Cranberry derived proanthocyanidins induce a state of iron-limitation in uropathogenic Escherichia coli CFT073 as revealed by microarray analysis
Project description:Transcriptional profiles of uropathogenic Escherichia coli CFT073 exposed to cranberry-derived proanthocyanidins (PACs) were determined. Our results indicate that bacteria grown on media supplemented with PACs were iron-deprived. To our knowledge, this is the first time that PACs have been shown to induce a state of iron-limitation in this bacterium.
Project description:Transcriptional profiles of uropathogenic Escherichia coli CFT073 exposed to cranberry-derived proanthocyanidins (PACs) were determined. Our results indicate that bacteria grown on media supplemented with PACs were iron-deprived. To our knowledge, this is the first time that PACs have been shown to induce a state of iron-limitation in this bacterium. Cultures of E. coli CFT073 were streaked onto LB agar plates and incubated (37°C, 24 h). A single colony was inoculated into 150 mL of LB broth. Three inoculated flasks contained LB broth alone (controls), and three inoculated flasks were supplemented with cranberry PACs (100 µg/mL). After incubation (37°C, 5 h, 200 rpm to mid-log growth phase), bacteria were harvested for RNA extraction.
Project description:The influence of cranberry proanthocyanidins on the transcriptomic responses of Streptococcus mutans during biofilm formation was investigated. Treatment regimens simulating topical exposures experienced clinically (twice-daily, 60 s each) were used over saliva-coated hydroxyapatite biofilm model. Cranberry proanthocyanidins (1.5 mg/ml) in 15% ethanol was used to treat the biofilms. Four biological replicates each for the treatment and vehicle control were used for RNA extraction and microarray.
Project description:The influence of cranberry proanthocyanidins on the transcriptomic responses of Streptococcus mutans during biofilm formation was investigated.
Project description:Here we dissected a regulatory network directed by the conserved iron homeostasis regulator, Ferric Uptake Regulator (Fur), in uropathogenic E. coli strain CFT073. Comparing anaerobic genome-scale Fur DNA binding, with Fur dependent transcript expression and protein levels of the uropathogen to that of commensal E. coli K-12 strain MG1655, showed that the Fur regulon of the core genome is conserved but also includes genes within the pathogenicity/genetic islands. Unexpectedly, regulons indicative of amino acid limitation and the general stress response were also indirectly activated in the uropathogen fur mutant, suggesting that induction of the Fur regulon increases amino acid demand. Using RpoS levels as a proxy, addition of amino acids mitigated the stress. In addition, iron chelation increased RpoS to the same levels as in the fur mutant. The increased amino acid demand of the fur mutant or iron chelated cells was exacerbated by aerobic conditions, which could be partly explained by the O 2 -dependent synthesis of the siderophore aerobactin, encoded within a pathogenicity island. Taken together, this data suggest in the iron-poor environment of the urinary tract, amino acid availability could play a role in the proliferation of this uropathogen, particularly if there is sufficient O 2 to produce aerobactin.
Project description:Several different mechanisms have been proposed to explain the possible role of cranberries, cranberry juice, and cranberry extracts in inhibiting bacterial growth. In this report, we showed that Escherichia coli showed slower growth rate in response to the presence of cranberry juice in the growth media. By compareing the global transcript profiles, significant modulation of several genes of E. coli grown in LB broth with 10% cranberry juice were identified and provided identification of the potential mechanisms involved in the inhibitory effects of cranberry juice. The results presented clearly demonstrate that the inhibitory effect on bacterial growth observed in the presence of cranberry juice/extracts is primarily a result of the iron chelation capacity of PACs and direct disruption of metabolic enzymes. The results are discussed with a focus on the genes associated with iron chelation capability. Keywords: growth inhibition of cranberry juice
Project description:E. coli which cause urinary tract infections must respond to high osmolarity in the urinary tract as well as the presence of urea. We used microarrays to measure the differntial gene expression of uropathogenic strain CFT073 in conditions of high osmolarity of urea v. minimal media RNA was extracted from CFT073 in each growth condition and hybridized to an Affymetrix microarray. The differentially expressed genes were analyzed by expression pattern and function.
Project description:Plant-based foods contain bioactive compounds such as polyphenols that resist digestion and potentially benefit the host through interactions with their gut microbiome. Based on previous observations, we hypothesized thatprobiotic Lactobacillus plantarum interact with cranberry polyphenols and dietary oligosaccharides to synergistically impact its physiology. In this study, L. plantarum ATCC BAA-793 was grown on dietary oligosaccharides including cranberry xyloglucans, fructooligosaccharides, and human milk oligosaccharidesin conjunction with proanthocyanidins (PACs) extracted from cranberry. As a result, L. plantarum exhibits a differential physiological response to cranberry PACs dependent on the carbohydrate source and polyphenol fraction introduced. Of two extracts evaluated, the PAC1 fraction increased growth regardless of oligosaccharide whereas PAC2 positively modulates growth during xyloglucan metabolism. Interestingly, PAC1 enables ATCC BAA-793 to utilize fructooligosaccharides efficiently as it is unable to ferment this substrate ordinarily. Relative to glucose, oligosaccharide metabolism increases the ratio of secreted acetic acid to lactic acid. The PAC2 fraction differentially increases this ratio during cranberry xyloglucan fermentation compared with PAC1. RNA-seq transcriptomics link expression of putative polyphenol degradation genes, polyphenol degradation profiles, and physiological phenotypes.
Project description:Several different mechanisms have been proposed to explain the possible role of cranberries, cranberry juice, and cranberry extracts in inhibiting bacterial growth. In this report, we showed that Escherichia coli showed slower growth rate in response to the presence of cranberry juice in the growth media. By compareing the global transcript profiles, significant modulation of several genes of E. coli grown in LB broth with 10% cranberry juice were identified and provided identification of the potential mechanisms involved in the inhibitory effects of cranberry juice. The results presented clearly demonstrate that the inhibitory effect on bacterial growth observed in the presence of cranberry juice/extracts is primarily a result of the iron chelation capacity of PACs and direct disruption of metabolic enzymes. The results are discussed with a focus on the genes associated with iron chelation capability. Keywords: growth inhibition of cranberry juice For transcriptome profiling, there were 15 Affymetrix GeneChip® E. coli genome 2.0 arrays total. There were five conditions: E. coli grown in LB broth, E. coli grown in LB broth with 10% cranberry juice to generation 50, 160, 210, and 230. Each condition was done in triplicate. Five conditions done in triplicates resulted in 15 samples that went onto 15 microarrays.
Project description:E. coli which cause urinary tract infections must respond to high osmolarity in the urinary tract as well as the presence of urea. We used microarrays to measure the differntial gene expression of uropathogenic strain CFT073 in conditions of high osmolarity of urea v. minimal media