Enterotoxigenic Escherichia coli CS21 pilus contributes to adhesion to intestinal cells and to pathogenesis under in vivo conditions

Pharmacological levels of zinc oxide in the post-weaning piglet diet reduce the incidence and severity of diarrhoea, in particular that caused by enterotoxigenic Escherichia coli (ETEC) K88 (Owusu-Asiedu et al. 2003). A previous in vivo genomic study (Sargeant et al, 2008) identified several genes differentially expressed in the small intestine of ETEC-challenged piglets when fed a zinc oxide-supplemented diet. This included decreased expression of several genes involved in the inflammatory and innate immune response. It has been reported that ZnO reduces adhesion and internalisation of K88 to cultured human enterocytes, counteracting the up-regulation of inflammatory cytokines caused by ETEC infection. However, this effect was not due to growth inhibition of ETEC K88 in ZnO (Roselli et al, 2003). The objective of this study was to determine whether zinc oxide shows the same mode of action in protecting porcine intestinal cells against ETEC K88 as has been demonstrated in human cells, providing an explanation for in vivo findings.

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In Vitro and In Vivo Assessment of the Potential of Escherichia coli Phages to Treat Infections and Survive Gastric Conditions

Microorganisms ◽

10.3390/microorganisms9091869 ◽

2021 ◽

Vol 9 (9) ◽

pp. 1869

Author(s):

Joanna Kaczorowska ◽

Eoghan Casey ◽

Gabriele A. Lugli ◽

Marco Ventura ◽

David J. Clarke ◽

...

Keyword(s):

Escherichia Coli ◽

Galleria Mellonella ◽

Enterotoxigenic Escherichia Coli ◽

E Coli ◽

Composite Mixture ◽

Ph Conditions ◽

The Stability ◽

Higher Sensitivity

Enterotoxigenic Escherichia coli (ETEC) and Shigella ssp. infections are associated with high rates of mortality, especially in infants in developing countries. Due to increasing levels of global antibiotic resistance exhibited by many pathogenic organisms, alternative strategies to combat such infections are urgently required. In this study, we evaluated the stability of five coliphages (four Myoviridae and one Siphoviridae phage) over a range of pH conditions and in simulated gastric conditions. The Myoviridae phages were stable across the range of pH 2 to 7, while the Siphoviridae phage, JK16, exhibited higher sensitivity to low pH. A composite mixture of these five phages was tested in vivo in a Galleria mellonella model. The obtained data clearly shows potential in treating E. coli infections prophylactically.

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CfaD-Dependent Expression of a Novel Extracytoplasmic Protein from Enterotoxigenic Escherichia coli

Journal of Bacteriology ◽

10.1128/jb.00131-07 ◽

2007 ◽

Vol 189 (14) ◽

pp. 5060-5067 ◽

Cited By ~ 33

Author(s):

M. Carolina Pilonieta ◽

Maria D. Bodero ◽

George P. Munson

Keyword(s):

Escherichia Coli ◽

Binding Sites ◽

Secretory Pathway ◽

Dnase I ◽

Enterotoxigenic Escherichia Coli ◽

Watery Diarrhea ◽

Dnase I Footprinting ◽

Virulence Regulator

ABSTRACT H10407 is a strain of enterotoxigenic Escherichia coli (ETEC) that utilizes CFA/I pili to adhere to surfaces of the small intestine, where it elaborates toxins that cause profuse watery diarrhea in humans. Expression of the CFA/I pilus is positively regulated at the level of transcription by CfaD, a member of the AraC/XylS family. DNase I footprinting revealed that the activator has two binding sites upstream of the pilus promoter cfaAp. One site extends from positions −23 to −56, and the other extends from positions −73 to −103 (numbering relative to the transcription start site of cfaAp). Additional CfaD binding sites were predicted within the genome of H10407 by computational analysis. Two of these sites lie upstream of a previously uncharacterized gene, cexE. In vitro DNase I footprinting confirmed that both sites are genuine binding sites, and cexEp::lacZ reporters demonstrated that CfaD is required for the expression of cexE in vivo. The amino terminus of CexE contains a secretory signal peptide that is removed during translocation across the cytoplasmic membrane through the general secretory pathway. These studies suggest that CexE may be a novel ETEC virulence factor because its expression is controlled by the virulence regulator CfaD, and its distribution is restricted to ETEC.

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Icariin and its phosphorylated derivatives alleviate intestinal epithelial barrier disruption caused by enterotoxigenic Escherichia coli through modulate p38 MAPK in vivo and in vitro

The FASEB Journal ◽

10.1096/fj.201902265r ◽

2019 ◽

Vol 34 (1) ◽

pp. 1783-1801 ◽

Cited By ~ 4

Author(s):

Wen Xiong ◽

Jing Huang ◽

Xueying Li ◽

Zhu Zhang ◽

Meilan Jin ◽

...

Keyword(s):

Escherichia Coli ◽

P38 Mapk ◽

Enterotoxigenic Escherichia Coli ◽

Epithelial Barrier ◽

Intestinal Epithelial ◽

Intestinal Epithelial Barrier ◽

Barrier Disruption

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Cooperative Role of Antibodies against Heat-Labile Toxin and the EtpA Adhesin in Preventing Toxin Delivery and Intestinal Colonization by Enterotoxigenic Escherichia coli

Clinical and Vaccine Immunology ◽

10.1128/cvi.00351-12 ◽

2012 ◽

Vol 19 (10) ◽

pp. 1603-1608 ◽

Cited By ~ 20

Author(s):

Koushik Roy ◽

David J. Hamilton ◽

James M. Fleckenstein

Keyword(s):

Escherichia Coli ◽

Diarrheal Disease ◽

Vaccine Development ◽

Enterotoxigenic Escherichia Coli ◽

Intestinal Colonization ◽

Content Type ◽

Heat Labile

ABSTRACTEnterotoxigenicEscherichia coli(ETEC) is an important cause of diarrheal disease in developing countries, where it is responsible for hundreds of thousands of deaths each year. Vaccine development for ETEC has been hindered by the heterogeneity of known molecular targets and the lack of broad-based sustained protection afforded by existing vaccine strategies. In an effort to explore the potential role of novel antigens in ETEC vaccines, we examined the ability of antibodies directed against the ETEC heat-labile toxin (LT) and the recently described EtpA adhesin to prevent intestinal colonizationin vivoand toxin delivery to epithelial cellsin vitro. We demonstrate that EtpA is required for the optimal delivery of LT and that antibodies against this adhesin play at least an additive role in preventing delivery of LT to target intestinal cells when combined with antibodies against either the A or B subunits of the toxin. Moreover, vaccination with a combination of LT and EtpA significantly impaired intestinal colonization. Together, these results suggest that the incorporation of recently identified molecules such as EtpA could be used to enhance current approaches to ETEC vaccine development.

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In vivo therapeutic efficacy and pharmacokinetics of colistin sulfate in an experimental model of enterotoxigenic Escherichia coli infection in weaned pigs

Veterinary Research ◽

10.1186/s13567-016-0344-y ◽

2016 ◽

Vol 47 (1) ◽

Cited By ~ 12

Author(s):

Mohamed Rhouma ◽

Francis Beaudry ◽

William Thériault ◽

Nadia Bergeron ◽

Guy Beauchamp ◽

...

Keyword(s):

Escherichia Coli ◽

Experimental Model ◽

Therapeutic Efficacy ◽

Enterotoxigenic Escherichia Coli ◽

Weaned Pigs ◽

Colistin Sulfate ◽

Escherichia Coli Infection

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Genetic Diversity of Heat-Labile Toxin Expressed by Enterotoxigenic Escherichia coli Strains Isolated from Humans

Journal of Bacteriology ◽

10.1128/jb.00988-07 ◽

2008 ◽

Vol 190 (7) ◽

pp. 2400-2410 ◽

Cited By ~ 26

Author(s):

M. A. Lasaro ◽

J. F. Rodrigues ◽

C. Mathias-Santos ◽

B. E. C. Guth ◽

A. Balan ◽

...

Keyword(s):

Escherichia Coli ◽

Cultured Cells ◽

Rflp Analysis ◽

Restriction Enzymes ◽

Amino Acid Sequences ◽

Enterotoxigenic Escherichia Coli ◽

Heat Labile ◽

Natural Diversity

ABSTRACT The natural diversity of the elt operons, encoding the heat-labile toxin LT-I (LT), carried by enterotoxigenic Escherichia coli (ETEC) strains isolated from humans was investigated. For many years, LT was supposed to be represented by a rather conserved toxin, and one derivative, produced by the reference H10407 strain, was intensively studied either as a virulence factor or as a vaccine adjuvant. Amplicons encompassing the two LT-encoding genes (eltA and eltB) of 51 human-derived ETEC strains, either LT+ (25 strains) only or LT+/ST+ (26 strains), isolated from asymptomatic (24 strains) or diarrheic (27 strains) subjects, were subjected to restriction fragment length polymorphism (RFLP) analysis and DNA sequencing. Seven polymorphic RFLP types of the H10407 strain were detected with six (BsaI, DdeI, HhaI, HincII, HphI, and MspI) restriction enzymes. Additionally, the single-nucleotide polymorphic analysis revealed 50 base changes in the elt operon, including 21 polymorphic sites at eltA and 9 at eltB. Based on the deduced amino acid sequences, 16 LT types were identified, including LT1, expressed by the H10407 strain and 23 other strains belonging to seven different serotypes, and LT2, expressed by 11 strains of six different serotypes. In vitro experiments carried out with purified toxins indicated that no significant differences in GM1-binding affinity could be detected among LT1, LT2, and LT4. However, LT4, but not other toxin types, showed reduced toxic activities measured either in vitro with cultured cells (Y-1 cells) or in vivo in rabbit ligated ileal loops. Collectively, these results indicate that the natural diversity of LTs produced by wild-type ETEC strains isolated from human hosts is considerably larger than previously assumed and may impact the pathogeneses of the strains and the epidemiology of the disease.

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Mutagenesis of the Rns regulator of enterotoxigenic Escherichia coli reveals roles for a linker sequence and two helix–turn–helix motifs

Microbiology ◽

10.1099/mic.0.038521-0 ◽

2010 ◽

Vol 156 (9) ◽

pp. 2796-2806 ◽

Cited By ~ 8

Author(s):

Vivienne Mahon ◽

Cyril J. Smyth ◽

Stephen G. J. Smith

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Amino Acid ◽

Amino Acid Sequence ◽

Protein A ◽

Diarrhoeal Disease ◽

Enterotoxigenic Escherichia Coli ◽

Insertion Mutagenesis

The pathogenesis of diarrhoeal disease due to human enterotoxigenic Escherichia coli absolutely requires the expression of fimbriae. The expression of CS1 fimbriae is positively regulated by the AraC-like protein Rns. AraC-like proteins are DNA-binding proteins that typically contain two helix–turn–helix (HTH) motifs. A program of pentapeptide insertion mutagenesis of the Rns protein was performed, and this revealed that both HTH motifs are required by Rns to positively regulate CS1 fimbrial gene expression. Intriguingly, a pentapeptide insertion after amino acid C102 reduced the ability of Rns to transactivate CS1 fimbrial expression. The structure of Rns in this vicinity (NACRS) was predicted to be disordered and thus might act as a flexible linker. This hypothesis was confirmed by deletion of this amino acid sequence from the Rns protein; a truncated protein that lacked this sequence was no longer functional. Strikingly, this sequence could be functionally substituted in vivo and in vitro by a flexible seven amino acid sequence from another E. coli AraC-like protein RhaS. Our data indicate that HTH motifs and a flexible sequence are required by Rns for maximal activation of fimbrial gene expression.

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