Escherichia coli O157:H7 str. Sakai
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ABSTRACT:
PROVIDER: PRJNA118749 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Transcript abundance in Escherichia coli O157:H7 was determined in the presence or absence of pulsed expression of the small RNA, AsxR.
2014-05-22 | GSE46113 | GEO
Project description:Transcriptomic analysis for Pch/ Ler regulon in enterohaemorrhagic Escherichia coli O157:H7
| PRJNA103679 | ENA
Project description:There is increasing evidence to support a role for sigma factor 54 (RpoN) in the regulation of stress resistance factors and protein secretion systems important to bacterial transmission and pathogenesis. In enterohemorrhagic E. coli O157:H7, acid resistance and type III secretion are essential determinants of gastric passage and colonization. This study thus described the transcriptome of an rpoN null strain of E. coli O157:H7 (EcJR-8) to determine the influence of RpoN on virulence and stress resistance gene regulation, and further explored its contribution to glutamate-dependent acid resistance (GDAR). Inactivation of rpoN resulted in the growth phase-dependent, differential expression of 104 genes. This included type III secretion structural and regulatory genes encoded on the locus of enterocyte effacement (LEE), as well as GDAR genes gadA, gadBC and gadE. Upregulation of gad transcript levels in EcJR-8 during logarithmic growth correlated with increased GDAR and survival in a model stomach. Acid susceptibility was reconstituted in EcJR-8 complemented in trans with wild-type rpoN. Acid resistance in EcJR-8 was dependent on exogenous glutamate, gadE and rpoS, but was independent of hns. Results also suggest that GDAR may be controlled by RpoN at multiple regulatory levels. This study supports the hypothesis that RpoN is an important regulator of virulence and stress resistance factors in E. coli O157:H7, and is the first to examine the mechanism by which it represses GDAR.
2009-08-08 | GSE17467 | GEO
Project description:Deletion of yedL was found to signifcantly decrease type three secretion in EHEC O157:H7. Transcriptional profiles of Escherichia coli O157: H7 and the isogenic yedL mutant were generated and compared.
2017-07-24 | GSE15265 | GEO
Project description:Deletion of yhaO was found to signifcantly decrease type three secretion in EHEC O157:H7. Transcriptional profiles of Escherichia coli O157: H7 and the isogenic yhaO mutant were generated and compared.
2017-07-24 | GSE15261 | GEO
Project description:Escherichia coli O157:H7 str. Sakai Genome sequencing
| PRJNA171729 | ENA
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.
2012-07-05 | GSE30424 | GEO
Project description:There is increasing evidence to support a role for sigma factor 54 (RpoN) in the regulation of stress resistance factors and protein secretion systems important to bacterial transmission and pathogenesis. In enterohemorrhagic E. coli O157:H7, acid resistance and type III secretion are essential determinants of gastric passage and colonization. This study thus described the transcriptome of an rpoN null strain of E. coli O157:H7 (EcJR-8) to determine the influence of RpoN on virulence and stress resistance gene regulation, and further explored its contribution to glutamate-dependent acid resistance (GDAR). Inactivation of rpoN resulted in the growth phase-dependent, differential expression of 104 genes. This included type III secretion structural and regulatory genes encoded on the locus of enterocyte effacement (LEE), as well as GDAR genes gadA, gadBC and gadE. Upregulation of gad transcript levels in EcJR-8 during logarithmic growth correlated with increased GDAR and survival in a model stomach. Acid susceptibility was reconstituted in EcJR-8 complemented in trans with wild-type rpoN. Acid resistance in EcJR-8 was dependent on exogenous glutamate, gadE and rpoS, but was independent of hns. Results also suggest that GDAR may be controlled by RpoN at multiple regulatory levels. This study supports the hypothesis that RpoN is an important regulator of virulence and stress resistance factors in E. coli O157:H7, and is the first to examine the mechanism by which it represses GDAR. Hybridizations measured transcriptional differences between an rpoN null and wild-type (WT) strain of E. coli O157:H7 Sakai at logarithmic and transition phase. Image files (TIFF) of hybridized microarray slides were generated using an Axon 4000B scanner (Molecular Devices), and analyzed using GenePix Pro software (Molecular Devices, ver. 6.0). The resulting microarray intensity data was log2-transformed, and normalized using the LOWESS algorithm in MAANOVA ver. 0.98-8 (R ver. 2.2.1).
2009-08-08 | E-GEOD-17467 | biostudies-arrayexpress
Project description:Cinnamaldehyde is a natural antimicrobial and has been found to be effective against many foodborne pathogens including Escherichia coli O157:H7. Although its antimicrobial effects have been well investigated, limited information is available on its effects at the molecular level. Sublethal treatment at 200 mg/l cinnamaldehyde inhibited growth of E. coli O157:H7 at 37oC and for ≤ 2 h caused cell elongation, but from 2 to 4 h growth resumed and cells reverted to normal length. To understand this transient behaviour, genome-wide transcriptional analysis of E. coli O157:H7 was performed at 2 and 4 h exposure to cinnamaldehyde. Drastically different gene expression profiles were obtained at 2 and 4 h. At 2 h exposure, cinnamaldehyde induced overexpression of many oxidative stress-related genes, reduced DNA replication, and synthesis of protein, O-antigen and fimbriae. At 4 h, many cinnamaldehyde-induced repressive effects on E. coli O157:H7 gene expressions were reversed and oxidatve stress genes were nolonger differentially expressed.
2012-09-08 | GSE40693 | 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 an anaerobic environment on E. coli O157:H7, global transcript levels of strain EDL933 cells grown aerobically were compared to cells grown anaerobically using microarrays.
2010-12-01 | GSE13301 | GEO