Ginkgolic acids and Ginko biloba extract inhibit Escherichia coli O157:H7 biofilm formation
Ontology highlight
ABSTRACT:
ORGANISM(S): Escherichia coli O157:H7 str. EDL933
SUBMITTER: Jintae Lee
PROVIDER: E-GEOD-49367 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Contamination with enterohemorrhagic Escherichia coli O157:H7 (EHEC) is a worldwide problem but there is no effective therapy available for EHEC infection. Biofilm formation is closely related with EHEC infection and is one of the mechanisms of antimicrobial resistance. Antibiofilm screening of 560 plant secondary metabolites against EHEC shows that ginkgolic acids C15:1 and C17:1 at 5 μg/ml and Ginko biloba extract at 100 μg/ml significantly inhibited EHEC biofilm formation on the surface of polystyrene, nylon membrane, and glass. Importantly, the working concentration of ginkgolic acids and G. biloba extract did not affect bacterial growth and has been known to be non-toxic to human. Transcriptional analyses showed that ginkgolic acid C15:1 repressed curli genes and prophage genes in EHEC, which were corroborated by reduced fimbriae production and biofilm reduction in EHEC. Interestingly, ginkgolic acids and G. biloba extract did not inhibit the biofilm formation of commensal E. coli K-12 strain. The current study suggests that plant secondary metabolites are important resource of biofilm inhibitors, as well as other bioactive compounds.
2015-07-29 | GSE49367 | GEO
Project description:Two lineages of enterohemorrhagic (EHEC) Escherichia coli O157:H7 (EDL933, Stx1+ and Stx2+) and 86-24 (Stx2+) were investigated in regards to biofilm formation on an abiotic surface. Strikingly, EDL933 strain formed a robust biofilm while 86-24 strain formed no biofilm on either a polystyrene plate or a polyethylene tube. To identify the genetic mechanisms of different biofilm formation in two EHEC strains, DNA microarrays were first performed and phenotypic assays were followed. In the comparison of the EDL933 strain versus 86-24 strain, genes (csgBAC and csgDEFG) involved in curli biosynthesis were significantly induced while genes (trpLEDCB and mtr) involved in indole signaling were repressed. Additionally, a dozen of phage genes were differentially present between two strains. Curli assays using a Congo red plate and scanning electron microscopy corroborate the microarray data as the EDL 933 strain produces a large amount of curli, while 86-24 forms much less curli. Also, the indole production in the EDL933 was 2-times lower than that of 86-24. It was known that curli formation positively regulates and indole negatively regulates biofilm formation of EHEC. Hence, it appears that less curli formation and high indole production in the 86-24 strain are majorly responsible for no biofilm formation. For the microarray experiments, E. coli O157:H7 EDL933 and 86-24 were inoculated in 25 ml of LB in 250 ml shake flasks with overnight cultures that were diluted 1:100. Cells were shaken at 250 rpm and 37°C for an absorbance of 4.0 at 600 nm. Cells were immediately chilled with dry ice and 95% ethanol (to prevent RNA degradation) for 30 sec before centrifugation in 50 ml centrifuge tubes at 13,000 g for 2 min; cell pellets were frozen immediately with dry ice and stored -80°C. RNA was isolated using Qiagen RNeasy mini Kit (Valencia, CA, USA). RNA quality was assessed by Agilent 2100 bioanalyser using the RNA 6000 Nano Chip (Agilent Technologies, Amstelveen, The Netherlands), and quantity was determined by ND-1000 Spectrophotometer (NanoDrop Technologies, Inc., DE, USA).
2011-01-19 | E-GEOD-19953 | biostudies-arrayexpress
Project description:Pathogenic biofilms have been associated with persistent infections due to their high resistance to antimicrobial agents. To identify non-toxic biofilm inhibitors for enterohemorrhagic Escherichia coli O157:H7, indole-3-acetaldehyde was used and reduced E. coli O157:H7 biofilm formation. Global transcriptome analyses revealed that indole-3-acetaldehyde most repressed two curli operons, csgBAC and csgDEFG, and induced tryptophanase (tnaAB) in E. coli O157:H7 biofilm cells. Electron microscopy showed that indole-3-acetaldehyde reduced curli production in E. coli O157:H7. Together, this study shows that Actinomycetales are an important resource of biofilm inhibitors as well as antibiotics. For the microarray experiments, E. coli O157:H7 EDL933 was inoculated in 100 ml of LB in 250 ml flasks with overnight cultures that were diluted at 1:100. Cells were shaken with 10g of glass wool at 250 rpm and 37°C for 7 hrs. Cells were immediately chilled with dry ice and 95% ethanol (to prevent RNA degradation) for 30 sec before centrifugation in 50 ml centrifuge tubes at 13,000 g for 2 min; cell pellets were frozen immediately with dry ice and stored -80°C. RNA was isolated using Qiagen RNeasy mini Kit (Valencia, CA, USA). To eliminate DNA contamination, Qiagen RNase-free DNase I was used to digest DNA. RNA quality was assessed by Agilent 2100 bioanalyser using the RNA 6000 Nano Chip (Agilent Technologies, Amstelveen, The Netherlands), and quantity was determined by ND-1000 Spectrophotometer (NanoDrop Technologies, Inc., DE, USA).
2012-07-04 | E-GEOD-30424 | biostudies-arrayexpress
Project description:Honey has been widely used against bacterial infection for centuries. Previous studies suggested that honeys in high concentrations inhibited bacterial growth due to the presence of anti-microbial compounds, such as methylglyoxal, hydrogen peroxide, and peptides. In this study, we found that three honeys (acacia, clover, and polyfloral) in a low concentration as below as 0.5% (v/v) significantly suppress virulence and biofilm formation in enterohemorrhagic E. coli O157:H7 affecting the growth of planktonic cells while these honeys do not harm commensal E. coli K-12 biofilm formation. Transcriptome analyses show that honeys (0.5%) markedly repress quorum sensing genes (e.g., AI-2 import and indole biosynthesis), virulence genes (e.g., LEE genes), and curli genes (csgBAC). We found that glucose and fructose in honeys are key compounds to reduce the biofilm formation of E. coli O157:H7 via suppressing curli production, but not that of E. coli K-12. Additionally, we observed the temperature-dependent response of honeys and glucose on commensal E. coli K-12 biofilm formation; honey and glucose increase E. coli K-12 biofilm formation at 37°C, while they decrease E. coli K-12 biofilm formation at 26°C. These results suggest that honey can be a practical tool for reducing virulence and colonization of the pathogenic E. coli O157:H7, while honeys do not harm commensal E. coli community in the human. For the microarray experiments, E. coli O157:H7 EDL933 was inoculated in 250 ml of LB in 1000 ml flasks with overnight cultures that were diluted at 1:100. Cells were shaken with 10g of glass wool at 100 rpm and 37°C for 7 hrs. Cells were immediately chilled with dry ice and 95% ethanol (to prevent RNA degradation) for 30 sec before centrifugation in 50 ml centrifuge tubes at 13,000 g for 2 min; cell pellets were frozen immediately with dry ice and stored -80°C. RNA was isolated using Qiagen RNeasy mini Kit (Valencia, CA, USA). To eliminate DNA contamination, Qiagen RNase-free DNase I was used to digest DNA. RNA quality was assessed by Agilent 2100 bioanalyser using the RNA 6000 Nano Chip (Agilent Technologies, Amstelveen, The Netherlands), and quantity was determined by ND-1000 Spectrophotometer (NanoDrop Technologies, Inc., DE, USA).
2012-03-30 | E-GEOD-28193 | biostudies-arrayexpress
Project description:Pathogenic biofilms have been associated with persistent infections due to high resistance to antimicrobial agents while commensal biofilms often fortify host immune system. Hence, controlling biofilm formation of both pathogenic bacteria and commensal bacteria is important in bacteria-related diseases. We investigated the effect of plant flavonoids on biofilm formation of both enterohemorrhagic Escherichia coli O157:H7 and three commensal E. coli K-12 strains. Phloretin abundant in apples markedly reduced E. coli O157:H7 biofilm formation without affecting the growth of planktonic cells while phloretin did not harm commensal E. coli K-12 biofilms. Also, phloretin reduced E. coli O157:H7 attachment to human colon epithelial cells. Global transcriptome analyses revealed that phloretin repressed toxin genes (hlyE and stx2), autoinducer-2 importer genes (lsrACDBF), a curli gene (csgA), and a dozens of prophage genes in E. coli O157:H7 cells. Electron microscopy confirmed that phroretin reduced the curli production in E. coli O157:H7. In addition, phloretin suppressed TNF-α-induced inflammatory response in vitro using human colonic epithelial cells. Moreover, in the trinitrobenzene sulfonic acid (TNBS)-induced rat colitis model, phloretin significantly ameliorated colon inflammation and body weight loss. Taken together, our results suggest that phloretin may act as an inhibitor of E. coli O157:H7 biofilm formation as well as anti-inflammatory agent on inflammatory bowel diseases while leaving beneficial commensal E. coli biofilm intact. For the microarray experiments, E. coli O157:H7 EDL933 was inoculated in 25 ml of LB in 250 ml flasks with overnight cultures that were diluted at 1:100. Cells were shaken at 100 rpm and 37°C for 7 hrs. Cells were immediately chilled with dry ice and 95% ethanol (to prevent RNA degradation) for 30 sec before centrifugation in 50 ml centrifuge tubes at 13,000 g for 2 min; cell pellets were frozen immediately with dry ice and stored -80°C. RNA was isolated using Qiagen RNeasy mini Kit (Valencia, CA, USA). To eliminate DNA contamination, Qiagen RNase-free DNase I was used to digest DNA. RNA quality was assessed by Agilent 2100 bioanalyser using the RNA 6000 Nano Chip (Agilent Technologies, Amstelveen, The Netherlands), and quantity was determined by ND-1000 Spectrophotometer (NanoDrop Technologies, Inc., DE, USA).
2011-11-22 | E-GEOD-28144 | biostudies-arrayexpress
Project description:E. coli K-12 BW25113 mutant strain yncC expression in biofilm cells relative to E. coli wild-type strain expression in biofilm cells. All samples were cultured in LB with glasswool at 37C for 15 hours and E. coli K-12 MG1655 mutant yncC colony cells vs wild type colony cells in LB plates 15h 37C. Quorum-sensing signal autoinducer 2 (AI-2) stimulates Escherichia coli biofilm formation through the motility regulator MqsR that induces expression of the putative transcription factor encoded by yncC. Here we show YncC increases biofilm formation by decreasing mucoidy (corroborated by decreased exopolysaccharide production and increased sensitivity to bacteriophage P1 infection). Differential gene expression and gel shift assays demonstrated that YncC is a repressor of the predicted periplasmic protein-encoding gene ybiM which was corroborated by the isogenic yncC ybiM double mutation which repressed the yncC phenotypes (biofilm formation, mucoidy, and bacteriophage resistance). Through nickel-enrichment microarrays and additional gel shift assays, we found that the putative transcription factor B3023 (directly upstream of mqsR) binds the yncC promoter. Overexpressing MqsR, AI-2 import regulators LsrR/LsrK, and AI-2 exporter TqsA induced yncC transcription whereas the AI-2 synthase LuxS and B3023 repressed yncC. MqsR has a toxic effect on E. coli bacterial growth which is partially reduced by the b3023 mutation. Therefore, AI-2 quorum-sensing control of biofilm formation is mediated through regulator MqsR that induces expression of the transcription factor YncC which serves to inhibit the expression of periplasmic YbiM; this inhibition of YbiM prevents it from overexpressing exopolysaccharide (causing mucoidy) and prevents YbiM from inhibiting biofilm formation. Experiment Overall Design: Strains: E. coli K-12 BW25113 wild-type, mutant yncC Experiment Overall Design: and E. coli K-12 MG1655 wild-type, mutant yncC Experiment Overall Design: Medium: LB Experiment Overall Design: Biofilm grown on glasswool or colony cells growth in LB plates Experiment Overall Design: Time: 15 hours Experiment Overall Design: Temperature: 37C Experiment Overall Design: Cell type: biofilm or colony Experiment Overall Design: For the biofilm arrays in BW25113 background: Experiment Overall Design: Overnight cultures (16 h, 2.5 mL) of wild type E. coli BW25113 and BW25113 yncC in LB and LB with kanamycin (50 μg/mL), respectively, were used to inoculate 250 mL LB with 10 g of glass wool (Corning Glass Works, Corning, NY) for forming biofilm. After incubating at 37°C for 15 h with shaking (250 rpm), biofilm cells were prepared by rinsing and sonicating the glass wool in sterile 0.85% NaCl solution at 0°C as described before. The total RNA was isolated from biofilm cells as described previously. Experiment Overall Design: The E. coli Genechip antisense genome array (P/N 900381, Affymetrix, Santa Clara, CA) containing probes for more than 4200 open reading frames (ORFs) was used to analyze the complete E. coli transcriptome as described previously. Hybridizations were performed for 16 h and the total cell intensity was scaled automatically in the software to an average value of 630. The Gene Expression Technical Manual (Affymetrix) was followed for the procedures of DNA microarrays, and the GeneChip operating software (Affymetrix) was applied to analyze data of DNA microarrays. The data quality was assessed following the manufacturer's guidelines (GeneChip Expression Analysis: Data Analysis Fundamentals; Affymetrix) and also was based on the expected signals of E. coli BW25113 and the yncC mutant genotypes (e.g., signals of the deleted genes, araA and rhaA, were low for both BW25113 and BW25113 yncC, while the signal of yncC was low for the yncC mutant). A gene was identified as differentially-expressed when the P value based on the False Discovery Rate Method was less than 0.05 and the expression ratio was greater than threefold since the standard deviation for the expression ratio for all of genes was 2. Experiment Overall Design: for the colony arrays in MG1655 background: Experiment Overall Design: For the agar biofilm, fresh single colonies of wild-type E. coli MG1655 and MG1655 yncC were re-streaked on LB agar plates, incubated, and about 0.05 g of the colony cultures on LB plate were quickly transferred to 2-mL collection tubes. The total RNA was isolated from these colony cells as described previously. The E. coli GeneChip Genome 2.0 Array (Affymetrix, P/N 900551, Santa Clara, CA) containing 10,208 probe sets for open reading frames, rRNA, tRNA, and intergenic regions for four E. coli strains: MG1655, CFT073, O157:H7-Sakai, and O157:H7-EDL933, was used to analyze the complete E. coli transcriptome. A gene was identified as differentially-expressed when the P value based on the False Discovery Rate Method (Benjamini & Hochberg, 1995) was less than 0.05 and the expression ratio was greater than threefold since the standard deviation for the expression ratio for all of MG1655 genes (except the deleted yncC gene) was 2.
2008-04-07 | E-GEOD-8706 | biostudies-arrayexpress
Project description:VS94 gene expression at different time-points in SAPI medium in absence and presence of AI-2 was studied. Autoinducer-2 (AI-2) is produced by many species of bacteria, including various commensal bacteria and is involved in inter-species communication. Since, pathogens encounter AI-2 once they enter the human gastro-intestinal tract; we studied the effects of presence of AI-2 on various phenotypes associated with infection and colonization of enterohemorrhagic Escherichia coli (EHEC) namely, chemotaxis, motility and attachment to HeLa cells. AI-2 attracted EHEC when observed in agarose plug assays and also increased EHEC motility by 1.44-fold. AI-2 also increased EHEC attachment to HeLa cells by 1.6-fold; hence, suggesting that exposure to AI-2 inside the gastro-intestinal tract can play an important role in EHEC colonization. We then investigated the global effects of AI-2 on EHEC gene expression using DNA microarrays at various time-points. We found that AI-2 controls virulence gene expression and several other groups of genes (flagellar genes, iron related genes, biofilm genes etc.) associated with virulence in a time-dependent manner. Hence, through these studies we have shown that AI-2 may be a key component in EHEC infection of human gastro-intestinal tract. Experiment Overall Design: Strain: VS94 (EHEC luxS mutant) Experiment Overall Design: Medium: SAPI Experiment Overall Design: Temperature: 37C Experiment Overall Design: Cell type: Suspension Experiment Overall Design: Chemical: 100 uM AI-2 Experiment Overall Design: Overnight cultures of VS94 were diluted in SAPI medium to a turbidity of 0.1. The cells were allowed to grow to a turbidity of 0.5 at 37 oC and 100 µM AI-2 was added to the culture. In the control flasks, no AI-2 was added. The cultures were then allowed to grow for further 3.5 hours, 4 hours, 4.5 hours and 5.5 hours before cell pellets were collected by centrifugation at the above mentioned time-points and stored at -80oC. Experiment Overall Design: Total RNA was isolated from isolated cell pellets and RNA quality was assessed using gel electrophoresis. E. coli Genome 2.0 arrays (Affymetrix, California) containing 10,208 probe sets for all 20,366 genes present in four strains of E. coli, including E. coli O157:H7, were used to profile changes in gene expression using RNA samples for each treatment. Hybridization was performed for 16 hours, and the total cell intensity was scaled automatically in the software to an average value of 500. The data were inspected for quality and analyzed according to the procedures described by the manufacturer (Affymetrix: Data Analysis Fundamentals) which include using premixed polyadenylated transcripts of the B. subtilis genes (lys, phe, thr, and dap) at different concentrations. Genes were identified as differentially expressed if the expression ratio (between AI-2 and control cells at different time-points) was greater than 1.5 (based on the standard deviation between values measuring relative changes in expression) (Ren et al. 2004) and the change in the P value was less than 0.05. The differentially expressed genes were annotated using gene ontology definitions available in the Affymetrix NetAffx Analysis Center (http://www.affymetrix.com/analysis/index.affx).
2008-04-04 | E-GEOD-9388 | biostudies-arrayexpress
Project description:E coli O157H7 (EHEC) wildtype 7 hour biofilm cells studied in LB glucose medium with and without chemicals - Epinephrine, Norepinephrine and Indole. Biofilm cells were cultured from glass wool. Keywords: Effect of different chemicals on EHEC gene expression
2007-07-09 | GSE5552 | GEO
Project description:E coli O157H7 (EHEC) wildtype 7 hour biofilm cells studied in LB glucose medium with and without chemicals - Epinephrine, Norepinephrine and Indole. Biofilm cells were cultured from glass wool. Experiment Overall Design: Strain: E coli O157H7 (EHEC) Experiment Overall Design: Medium: LB-Glucose Experiment Overall Design: Chemicals: Epinephrine, Norepinephrine and Indole Experiment Overall Design: Time: 7 hours Experiment Overall Design: Cell type: Biofilm cells grown on glass wool
2008-06-13 | E-GEOD-5552 | biostudies-arrayexpress
Project description:The features of Mycoplasma in human organ such lung and urinary tract are enigmatic. Here, the role of M. hominis in regard to biofilm formation of uropathogenic Escherichia coli (UPEC) strain CFT073 was investigated. Although M. hominis were inferred to not impact on UPEC bacterial fitness including growth and productions of signaling molecules as autoinducer-2 (AI-2) and indole, we found that the presence of M. hominis dramatically decreased biofilm formation of UPEC CFT073 as well as slightly repressed attachment and cytotoxicity of that. Importantly, this activity was observed on UPEC strain specifically, not enterohemorrhagic E. coli (EHEC) strain that exists on intestine. Whole-transcriptome profiling and quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed PhoPQ system and anti-termination protein (encoded by ybcQ) participates on the reduction of biofilm formation by M. hominis (corroborated by qRT-PCR). Furthermore, collaborating with previous report that toxin-antitoxin (TA) system involved in biofilm formation, M. hominis increased on the transcriptions of toxin genes including hha (toxin gene in Hha-TomB TA system) and pasT (toxin part in PasT-PasI TA system). Hence, we propose that one possible role of M. hominis is to influence bacterial biofilm formation in urinary tract. Only fourteen genes were induced (2.5-fold) by the presence of M. hominis in Uropathogenic Escherichia coli (UPEC) biofilm cells. Among upregulated genes, ybcQ (encodes anti-termination protein Q homolog) and phoP/phoQ (encode DNA-binding response regulators in two-component regulatory system), were induced by the presence of M. hominis. Two-condition experiment, UPEC CFT073 alone vs. UPEC CFT073 with Mycoplasma hominis PG21 (10^5 ccu/ml). For preparing the total RNA, UPEC CFT073 cells were grown at 37°C in biofilm cells on glass wool with or without M. hominis for 24 h.
2016-01-08 | E-GEOD-43376 | biostudies-arrayexpress