Cranberry derived proanthocyanidins induce a state of iron-limitation in uropathogenic Escherichia coli CFT073 as revealed by microarray analysis
ABSTRACT: 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: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. Overall design: 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:In this study the transcriptional response of an ExPEC E. coli strain (CFT073) to human serum was investigated. In response, CFT073 up-regulated expression of iron and manganese acquisition systems and induced expression of iron regulated genes. High osmolarity of serum induced the osmotic shock response genes, promoting uptake of osmoprotectants by CFT073. Resistance of CFT073 to the bactericidal properties of serum involved increased expression of envelope stress regulators including CpxR, ?E and RcsB. Many of the up-regulated genes induced by active serum were regulated by the Rcs two component system. This system is triggered by envelope stress such as changes to cell wall integrity. RcsB-mediated serum resistance was conferred through induction of the exopolysaccharide colanic acid. Production of this exopolysaccharide may be protective while cell wall damage caused by serum components is repaired. Experimental Design: Two experiments are reported: 1) . The transcriptome of E. coli CFT073 exposed to LB supplemented with 50 % normal human serum was compared to that of bacteria grown in LB alone for 45 min, and 2) The transcriptome of CFT073 in response to normal healthy serum and heat inactivated serum (which has no bactericidal activity). Four biological replicates were performed per experiment with Dye swaps performed on sample replicates to eliminate any dye bias
Project description:B. cenocepacia J2315 was grown to mid-log phase in different media: LB broth, iso-sensitest broth, basal salt medium with glucose<br>at pH 7 and pH 6, basal salt medium at pH 7 with a reduced iron content, and basal salt medium with glycerol
Project description:Proteus mirabilis is a primary cause of complicated urinary tract infections (UTI). Surprisingly, iron acquisition systems have been poorly characterized in this uropathogen despite the urinary tract being iron-limited. In this report the transcriptome of strain HI4320, cultured under iron limitation, was examined using microarray analysis. Of genes upregulated at least 2-fold, 45 were statistically significant and comprise 21 putative iron-regulated systems. Two of these systems, PMI0229-0239 and PMI2596-2605, are organized in operons and appear to encode siderophore biosynthesis genes. Five microarrays comparing P. mirabilis HI4320 cultured in LB broth to P. mirabilis cultured in LB broth + 15 uM Desferal (an iron chelator) were analyzed. All five arrays are biological replicates; arrays #2 and 4 are dye swaps.
Project description:Gene expression profiling of EHEC and its luxS-deficient mutant strain which cannot produce autoinducer-2 molecule at the late log-phase in 0.6M NaCl LB broth (osmotic stress condition) against controls grown under normal osmotic condition (LB broth)
Project description:Burkholderia cenocepacia J2315 was grown at 37 degrees centigrade in LB broth to the beginning of stationary phase (18 hours incubation time). <br>The expression profile was compared to cultures harvested in mid-log phase (7 hours incubation time).<br>
Project description:This study explores the effects of prolonged stationary phase, on whole genome expression of Escherichia coli. In summary these results imply that prolonged stationary phase cells have shown less growth rate compared to fresh cells due to the low abundance of transcripts for translation initiation factor infC, and for all the seven rrn operons of 5S, 16S, 23S ribosomal RNA which further delayed in protein synthesis leading to low biomass in prolonged stationary phase cells. 28 days old E.coli cells were grown in the presence of LB broth and LB broth supplemented with 10% v/v glycerol. RNA was extracted from these samples, cDNA was prepared, fragmented cDNA was labled with labeling reagent and hybridized with Affymetrix E.coli2.0 genome array chips.Data was analysed to get the effect of glycerol on E.coli gene expression
Project description:To find the alterations of expression profiles of shigella flexneri, we performed DNA chip analysis and proteomic analysis at the same time. an overnight culture of the wild-type strain in LB broth was harvested and resuspended in 20 ml PBS buffer and then incubated in PBS at 37 degree and in rabbit ileum for 4 hours respectively.
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.