Escherichia coli O157:H7 Isolates Related to the 2006 Spinach-associated Outbreak Exhibit Distinct Transcriptional Profiles
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ABSTRACT:
ORGANISM(S): Escherichia coli O157:H7
SUBMITTER: Craig Parker
PROVIDER: E-GEOD-33131 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:We compared the transcriptional profiles of 12 E. coli O157:H7 isolates grown to stationary phase in LB broth. These isolates possess the same two enzyme PFGE profile and are related temporally or geographically to the above outbreak. These E. coli O157:H7 isolates included three clinical isolates, five isolates from separate bags of spinach, and single isolates from pasture soil, river water, cow feces, and a feral pig.
2011-11-01 | GSE33131 | GEO
Project description:Sodium benzoate is a widely used food antimicrobial in drinks and fruit juices. A microarray study was conducted to determine the transcriptional response of Escherichia coli O157:H7 to 0.5% (w/v) sodium benzoate. Stationary phase E. coli O157:H7 grown in 150 ml Luria-Bertani broth (LB) was exposed to 0 (control) and 0.5% sodium benzoate. Each treatment was duplicated and sampled at 0 (immediately after exposure), 5, 15, 30, and 60 min. Total RNA was extracted and analyzed with E. coli 2.0 Gene Chips.
2009-10-05 | GSE17519 | GEO
Project description:Sodium benzoate is a widely used food antimicrobial in drinks and fruit juices. A microarray study was conducted to determine the transcriptional response of Escherichia coli O157:H7 to 0.5% (w/v) sodium benzoate. Stationary phase E. coli O157:H7 grown in 150 ml Luria-Bertani broth (LB) was exposed to 0 (control) and 0.5% sodium benzoate. Each treatment was duplicated and sampled at 0 (immediately after exposure), 5, 15, 30, and 60 min. Total RNA was extracted and analyzed with E. coli 2.0 Gene Chips. Experiment Overall Design: Completely randomized design with 0% (control) and 0.5% (w/v) sodium benzoate treated cells were exposed for 0 (immediately after exposure), 5 min, 15 min, 30 min, and 60 min. Each experiment was replicated once and total RNA was extracted and Affymetrix prokaryotic protocol was followed to hybridize cDNA onto E. coli Genome 2.0 Arrays.
2009-10-09 | E-GEOD-17519 | 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: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:The transcriptome of Escherichia coli K-12 has been widely studied over a variety of conditions for the past decade while such studies involving E. coli O157:H7, its pathogenic cousin, are just now being conducted. To better understand the impact of rumen fluid on E. coli O157:H7, global transcript levels of strain EDL933 cells resuspended in heat clarified rumen fluid for 15 min were compared to cells resuspended in fresh LB using microarrays.
2010-12-01 | GSE16747 | GEO
Project description:The transcriptome of Escherichia coli K-12 has been widely studied over a variety of conditions for the past decade while such studies involving E. coli O157:H7, its pathogenic cousin, are just now being conducted. To better understand the impact of rumen fluid on E. coli O157:H7, global transcript levels of strain EDL933 cells resuspended in heat clarified rumen fluid for 15 min were compared to cells resuspended in fresh LB using microarrays. Seven independent RNA samples from rumen fluid treated cultures were paired with seven independent RNA samples from control cultures for hybridization to seven two-color microarrays. For three arrays, the control RNA sample was labeled with Cy3 dye and the experimental RNA sample was labeled with Cy5 dye, the dyes were reversed for the other four arrays to overcome dye bias.
2010-12-01 | E-GEOD-16747 | biostudies-arrayexpress
Project description:The effect of pooled immunoglobulins (IgG) on E. coli O157:H7 colonization and the course of disease in an EHEC mouse model was investigated showing an improved survival and decreased intestinal and renal pathology. Treatment was given after inoculation thereby corresponding to the clinical setting. In vitro studies identified E. coli serine protease EspP as the E. coli O157:H7 protein that IgG bound to, via the Fc fragment, in both murine and human IgG preparations, and blocked its enzymatic activity. EspP is a virulence factor previously shown to promote colonic cell injury and the uptake of Shiga toxin by intestinal cells. The results suggest that IgG in commercial preparations binds to EspP protecting the host from E. coli O157:H7 infection and could potentially be beneficial in patients.
2022-02-08 | PXD029563 | Pride
Project description:Curli are adhesive fimbriae of Enterobactericaeae and are involved in surface attachment, cell aggregation and biofilm formation. We previously reported that natural curli variants of E. coli O157:H7 (EcO157) displayed distinct acid resistance; however, this difference was not linked to the curli fimbriae per se. Here, we investigated the underlying molecular basis of this phenotypic divergence between the curli variants. Among curli-producing (C+) variants isolated from the 1993 U.S. hamburger-associated outbreaks strains, we identified large deletions in the rcsB gene that encodes the response regulator of RcsCDB two-component signal transduction system of rcsB ,. Further comparison of stress fitness revealed that C+ variants were also significantly more sensitive to heat shock, but remained similar resistance to osmotic stress and oxidative damage as curli-deficient (C-) variants. Transcriptomics analysis uncovered a large number of differentially expressed genes between the curli variants, characterized by the enhanced expression of genes related to biofilm formation, virulence, catabolic activity and nutrients uptake, but marked decrease in transcription of genes related to various stress resistance in C+ variants. Supplying C+ variants with a functional rcsB restored cells resistance to heat shock and acid challenge, but blocked the curli production, confirming that inactivation of RcsB in C+ variants was the basis of fitness segregation within the EcO157population. This study provides an example of how genome instability of EcO157promotes the intra-population diversification, generating sub-populations carrying an array of distinct phenotypes that may confer the pathogen survival advantages in host and nonhost environments. Three replicates for isolates RM6607R, RM6607W, RM6608R, RM6608W independently grown from single colonies in LB broth and incubated at 28M-BM-0C overnight on a shaker (150 rpm). The cells were collected by centrifugation, washed once in LBNS broth, and inoculated in 25ml of LBNS broth with a concentration equivalent to 0.001OD600 ml-1. The cultures were incubated at 28M-BM-0C for 24 h with aeration (150 rpm). At the end of incubation, ice-cold phenol-ethanol (5%:95%) solution was immediately added to culture at a final concentration of 20% (volume), and the mixture was incubated on ice for 30 min. The cells were collected by centrifugation at 4M-BM-0C and the pellets were stored at -80M-BM-0C until RNA extraction. The cells were collected by centrifugation, washed once in LBNS broth, and inoculated in 25ml of LBNS broth with a concentration equivalent to 0.001OD600 ml-1. The cultures were incubated at 28M-BM-0C for 24 h with aeration (150 rpm). At the end of incubation, ice-cold phenol-ethanol (5%:95%) solution was immediately added to culture at a final concentration of 20% (volume), and the mixture was incubated on ice for 30 min. The cells were collected by centrifugation at 4M-BM-0C and the pellets were stored at -80M-BM-0C until RNA extraction. RNA was isolated using Promega SV Total RNA kit. A type 2 gene expression experimental design was used, with fluorescently labeled genomic DNA as a reference channel in each experiment as described by Lucchini, S., et al. 2005. Infect Immun 73:88-102.
2012-08-31 | E-GEOD-39439 | biostudies-arrayexpress
Project description:Leafy green vegetables, such as lettuce, have been increasingly implicated in outbreaks of foodborne illnesses due to contamination by Escherichia coli O157:H7. While E. coli can survive in soils, colonize plants, and survive on produce, very little is known about the interaction of E. coli with the roots of growing lettuce plants. In these studies, a combination of microarray analyses and surface enhanced Raman spectroscopy (SERS) were used to gain a comprehensive understanding of bacterial genes involved in the colonization and growth of E. coli O157:H7 on lettuce roots and compared to E. coli K12 using a hydroponic system (HS) which we have reported in the previous studies. Using microarray, after three days of interaction with lettuce roots, 94 and 109 genes of E. coli O157:H7 were significantly up-regulated and down-regulated at least 1.5 fold, respectively. Only 8 genes were also found in the E. coli K12 up-regulated genes. No genes were found in the down-regulated genes clusters between those two strains. For E. coli O157:H7, forty out of the 94 up-regulated genes (43%) were involved in protein synthesis and were highly repressed compared to 40 out of 193 (23%) E. coli K12 up-regulated genes associated with protein synthesis. The wildtype of E.coli O157:H7 colonized two log CFU per root less compared to E. coli K12. Genes involved in biofilm modulation (bhsA and ybiM) were significantly up-regulated in E. coli O157:H7 and curli production (crl and csgA) were found important for E. coli K12 to attach to lettuce roots in the previous studies. BhsA mutant of E. coli O157:H7 was impaired in the colonization of lettuce roots. The SERS spectra of E. coli K12 and O157 controls (cells without interacting with roots) were very similar. The spectra of E. coli K12 and O157 exposed to the hydroponic system (HS) showed some differences in the nucleic acid, protein, and lipid regions compared with controls. The spectra of E. coli K12 HS cells exhibited significant differences compared to spectra from E. coli O157 HS cells in the RNA and protein regions. The overall band intensity of amide regions declined for E. coli O157 HS cells, while it increased for E. coli K12 HS cells. The intensity of the RNA bands of E. coli K12 HS cells were also found much higher than those of E. coli O157 HS cells. These findings were in agreement to our Microarray data. Our microarray and SERS data showed that E. coli K12 and O157:H7 behavior dramatically differently in colonizing on lettuce roots. Compared to K12, E. coli O157:H7 colonized less efficiently on lettuce roots. Escherichia coli O157:H7 strains were grown in the lettuce rhizosphere for three days. Transcriptional profiling of E. coli was compared between cells grown with and without rhizosphere . Three biological replicates of each treatment were prepared, and six microarray slides were used.
2012-03-28 | E-GEOD-36885 | biostudies-arrayexpress