The Escherichia coli K-12 nrf operon encodes a periplasmic nitrite reductase, the expression of which is driven from a single promoter, pnrf. Expression from pnrf is activated by the FNR transcription factor in response to anaerobiosis and further increased in response to nitrite by the response regulator proteins, NarL and NarP. FNR-dependent transcription is suppressed by the binding of two n...

In the past weeks, we witnessed the unfolding story of one of the largest ever reported outbreaks of haemolytic uremic syndrome (HUS) and bloody diarrhoea caused by Shiga toxin-producing Escherichia coli (STEC), also commonly referred to as verocytotoxinproducing E. coli (VTEC) and enterohaemorrhagic E. coli (EHEC) [1]. This outbreak has caused considerable suffering and resulted in a strain on...

Enterohaemorrhagic Escherichia coli (EHEC) constitute a subset of serotypes (E. coli O157 and some other serogroups) of Shiga toxin (Stx)-producing E. coli (STEC) firmly associated with severe human illnesses like bloody diarrhoea and haemolytic uraemic syndrome. Stx production is essential but not sufficient for EHEC virulence. Most strains are capable of colonising the intestinal mucosa of th...

The haemolysin from enterohaemorrhagic Escherichia coli (EHEC-Hly) and the serine protease EspPα are putative virulence factors of EHEC. We investigated the interplay between these secreted factors and demonstrate that EspPα cleaves the 107 kDa large EHEC-Hly. Degradation was observed when purified EspPα was added to a growing culture of an EHEC-Hly-expressing strain, with isolated proteins and...

Enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC) are closely related pathogens. During infection, EPEC and EHEC use a type III secretion system (TTSS) to translocate effector proteins into the infected cells and thereby modify specific host functions. These include transient filopodium formation which is Cdc42-dependent. Filopodia formation is followed by assembly ...

BACKGROUND Enterohaemorrhagic (EHEC) and enteropathogenic (EPEC) Escherichia coli epithelial cell adhesion is characterised by intimate attachment, and attaching and effacing (A/E) lesion formation. This event is mediated in part by intimin binding to another bacterial protein, Tir (translocated intimin receptor), which is exported by the bacteria and integrated into the host cell plasma membra...

background and objectives: enteropathogenic escherichia coli (epec) strains can be detected by serogrouping and the presence of enterocyte attaching- effacing (eae) gene. most epec strains belong to a certain o antigenic group. locus of enterocyte effacement (lee) pathogenicity island contains the eae gene and secretory proteins (esps) that introduce the attaching-effacing lesion. lee inserted ...

Enterohaemorrhagic Escherichia coli (EHEC), serotype O157 : H7 is a non-invasive, pathogenic bacterium that employs a type III secretion system (T3SS) to inject effector proteins into infected cells. In this study, we demonstrate that EHEC blocks tumour necrosis factor-alpha (TNFα)-induced NF-κB signalling in infected epithelial cells. HEK293T and INT407 epithelial cells were challenged with EH...

Shiga-toxin-producing Escherichia coli (STEC) of different serotypes are known to harbour large plasmids. The aim of this study was to investigate, using the example of the plasmid-encoded serine protease EspP, whether these plasmids are a uniform genetic element present in STEC. Examination of 201 diarrhoeagenic E. coli strains using a newly developed espP-specific PCR showed that espP is spec...

background: uropathogenic escherichia coli o- serogroups with their virulence factors are the most prevalent causes of utis. objectives: the present investigation was performed to study the virulence factors and o-serogroups profiles of upec isolated from iranian pediatric patients. patients and methods: this cross sectional investigation was performed on 100 urine samples collected from hospit...