Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Genomic Comparison of the O-antigen Biosynthesis Gene Clusters of E. coli O55 Strains Belonging to Three Lineages.

ABSTRACT: Typical enteropathogenic Escherichia coli (EPEC) O55:H7 is regarded as the closest relative of enterohemorrhagic E. coli (EHEC) O157:H7. Both serotypes usually express the γ1 intimin subclass and trigger actin polymerazation by the Tir-TccP pathway. However, atypical O55:H7 strains capable of triggering actin polymerization via the Tir-Nck pathway have recently been identified. In this study, we investigated the genotypic differences and phylogenetic relationships between typical and atypical O55:H7 strains. We show that the atypical O55:H7 strains, which express the θ intimin subclass and lack both tccP and tccP2, belong to an E. coli lineage distinct from the typical O55:H7 and from the EPEC O55:H6, which also uses the Tir-Nck actin polymerization pathway. We conducted genomic comparisons of the chromosomal regions covering the O-antigen gene cluster and its flanking regions between the three O55 lineages by restriction fragment length polymorphism analysis of PCR products and DNA sequencing analysis of about 65-kb chromosomal regions. This unexpectedly revealed that horizontal transfer of large fragments (≥ 40 kb) encoding the O55-antigen gene cluster and part of neighboring colanic acid gene cluster is involved in the emergence of the three O55 E. coli lineages. The data provide new insights into the mechanisms involved in the generation of a wide variety of O-serotypes in Gram-negative bacteria. Keywords: comparative genomic hybridization

ORGANISM(S): Escherichia coli

PROVIDER: GSE8889 | GEO | 2008/04/01

SECONDARY ACCESSION(S): PRJNA102271

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Genomic Comparison of the O-antigen Biosynthesis Gene Clusters of E. coli O55 Strains Belonging to Three Lineages.

Project description:Typical enteropathogenic Escherichia coli (EPEC) O55:H7 is regarded as the closest relative of enterohemorrhagic E. coli (EHEC) O157:H7. Both serotypes usually express the Î³1 intimin subclass and trigger actin polymerazation by the Tir-TccP pathway. However, atypical O55:H7 strains capable of triggering actin polymerization via the Tir-Nck pathway have recently been identified. In this study, we investigated the genotypic differences and phylogenetic relationships between typical and atypical O55:H7 strains. We show that the atypical O55:H7 strains, which express the Î¸ intimin subclass and lack both tccP and tccP2, belong to an E. coli lineage distinct from the typical O55:H7 and from the EPEC O55:H6, which also uses the Tir-Nck actin polymerization pathway. We conducted genomic comparisons of the chromosomal regions covering the O-antigen gene cluster and its flanking regions between the three O55 lineages by restriction fragment length polymorphism analysis of PCR products and DNA sequencing analysis of about 65-kb chromosomal regions. This unexpectedly revealed that horizontal transfer of large fragments (â¥ 40 kb) encoding the O55-antigen gene cluster and part of neighboring colanic acid gene cluster is involved in the emergence of the three O55 E. coli lineages. The data provide new insights into the mechanisms involved in the generation of a wide variety of O-serotypes in Gram-negative bacteria. Keywords: comparative genomic hybridization Total 8 test samples were analyzed. Genomic DNA from each test strain and a reference strain (O157 Sakai) were labeled with Cy3 and Cy5, respectively, and were cohybridized on a single array. Labeling and hybridization were performed twice independently.

2010-05-22 | E-GEOD-8889 | biostudies-arrayexpress

Transcriptomic profiles of host epithelial cells in response to actin rearrangement induced by atypical enteropathogenic Escherichia coli

Project description:Atypical enteropathogenic Escherichia coli (aEPEC) is amongst the leading causes of diarrheal disease worldwide. The colonization of the gut mucosa by aEPEC results in actin pedestal formation at the site of bacterial attachment. This cytoskeletal rearrangement is triggered by the interaction between the bacterial adhesin intimin and its receptor Tir, which is translocated through the type three secretion system, to the host cell. While some aEPEC require tyrosine phosphorylation of Tir and recruitment of the host Nck to trigger actin polymerization, certain aEPEC strains, whose Tir is not phosphorylated, rely on the effector EspFu for efficient actin remodeling. To understand how the host responds to these different actin polymerization signaling pathways, we analyzed gene expression changes in epithelial cells infected with pedestal-forming aEPEC strains using high-throughput RNA sequencing (RNA-seq).

2020-04-01 | GSE141446 | GEO

Atypical Enteropathogenic Escherichia coli Virulence Regulation by QseC Quorum Sensing Adrenergic Sensor

Project description:Atypical EPEC (aEPEC) strains are part of group of pathogens capable of forming the Attaching and Effacing (A/E) lesion. This lesion is characterized by intimate adherence of bacteria to enterocytes, and microvilli destruction. The genes responsible to cause that lesion are located in a pathogenicity island called Locus of Enterocyte Effacement (LEE). Transcription of LEE genes is subjected to various levels of regulation, including quorum sensing through autoinducer 3 (AI-3) system. AI-3 is an aromatic compound with similar characteristics to the epinephrine and norepinephrine hormones. This similarity allows bacteria to use these hormones and AI-3 to perform cell M-bM-^@M-^S to M-bM-^@M-^S cell signaling processes and bacteria - host communication processes in order to modulate its virulence. AI-3, epinephrine and norepinephrine are detected by a sensor kinase named quorum sensing E.coli regulator (QseC). In order to investigate the role of QseC and epinephrine in atypical EPEC O55:H7 virulence, we constructed a QseC mutant of this strain and performed transcription and phenotypic analyses in the presence or absence of epinephrine. We have reported here, for the first time, the quorum sensing QseC regulation of virulence genes in atypical EPEC. Our results shown that QseC is a global regulator of gene expression in aEPEC and positively regulates flagellar genes, LEE and non-LEE encoded factors. We also have shown that the presence of epinephrine could be sensed by other receptor that acts as negative regulator of LEE4 and LEE5 genes. Comparison of transcriptional regulation of enteropathogenic E. coli serotype O55:H7 wild type and the qseC mutant in the absence or presence of epinephrine signal to identify the regulated targets

2013-01-08 | E-GEOD-43325 | biostudies-arrayexpress

Clustering of Tir during E. coli infection affects Ca2+-dependent LPS internalisation leading to activation of pyroptosis in intestinal epithelial cells

Project description:Clustering of the Enteropathogenic (EPEC) Escherichia coli Tir effector, induced by its binding to Intimin, leads to pyroptotic cell death in macrophages. The effect of Tir clustering following EPEC infection of epithelial cells remains unexplored. In this study, we show that EPEC induces pyroptosis in an intestinal epithelial cell (IEC) line, in a Tir-dependent but actin polymerisation-independent manner, which was enhanced by priming with IFNγ. Mechanistically, Tir clustering induces rapid Ca2+ influx, which promotes internalisation of LPS, followed by activation of caspase-4. Chelation of extracellular Ca2+ or knockdown of caspase-4 inhibited cell death upon EPEC infection, whereas ATP-induced extracellular Ca2+ influx had the opposite effect confirming the regulatory role of calcium in the pathway. Additionally, IEC lines with low endogenous expression of caspase-4 were resistant to EPEC-induced cell death. We reveal a novel mechanism of LPS internalisation, following infection with an extracellular pathogen, leading to pyroptosis in IECs.

2020-10-28 | PXD018763 | Pride

Atypical Enteropathogenic Escherichia coli Virulence Regulation by QseC Quorum Sensing Adrenergic Sensor

Project description:Atypical EPEC (aEPEC) strains are part of group of pathogens capable of forming the Attaching and Effacing (A/E) lesion. This lesion is characterized by intimate adherence of bacteria to enterocytes, and microvilli destruction. The genes responsible to cause that lesion are located in a pathogenicity island called Locus of Enterocyte Effacement (LEE). Transcription of LEE genes is subjected to various levels of regulation, including quorum sensing through autoinducer 3 (AI-3) system. AI-3 is an aromatic compound with similar characteristics to the epinephrine and norepinephrine hormones. This similarity allows bacteria to use these hormones and AI-3 to perform cell – to – cell signaling processes and bacteria - host communication processes in order to modulate its virulence. AI-3, epinephrine and norepinephrine are detected by a sensor kinase named quorum sensing E.coli regulator (QseC). In order to investigate the role of QseC and epinephrine in atypical EPEC O55:H7 virulence, we constructed a QseC mutant of this strain and performed transcription and phenotypic analyses in the presence or absence of epinephrine. We have reported here, for the first time, the quorum sensing QseC regulation of virulence genes in atypical EPEC. Our results shown that QseC is a global regulator of gene expression in aEPEC and positively regulates flagellar genes, LEE and non-LEE encoded factors. We also have shown that the presence of epinephrine could be sensed by other receptor that acts as negative regulator of LEE4 and LEE5 genes.

2013-01-08 | GSE43325 | GEO

Escherichia coli O55:H7 str. USDA 5905

Project description:Escherichia coli O55:H7 str. USDA 5905

| PRJNA60065 | ENA

Project description:asymptomatic atypical EPEC

| PRJNA973688 | ENA

Escherichia coli O55:H7 str. CB9615

Project description:Escherichia coli O55:H7 str. CB9615 genome project

| PRJNA42729 | ENA

Escherichia coli O55:H7 str. RM12579

Project description:Escherichia coli O55:H7 str. RM12579 genome sequencing

| PRJNA68245 | ENA