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A Specific A/T Polymorphism in Western Tyrosine Phosphorylation B-Motifs Regulates Helicobacter pylori CagA Epithelial Cell Interactions

Helicobacter pylori persistently colonizes the human stomach, with mixed roles in human health. The CagA protein, a key host-interaction factor, is translocated by a type IV secretion system into host epithelial cells, where its EPIYA tyrosine phosphorylation motifs (TPMs) are recognized by host cell kinases, leading to multiple host cell signaling cascades. The CagA TPMs have been ...

A simplified and cost-effective enrichment protocol for the isolation of Campylobacter spp. from retail broiler meat without microaerobic incubation

Background To simplify the methodology for the isolation of Campylobacter spp. from retail broiler meat, we evaluated 108 samples (breasts and thighs) using an unpaired sample design. The enrichment broths were incubated under aerobic conditions (subsamples A) and for comparison under microaerobic conditions (subsamples M) as recommended by current reference protocols. Sensors were ...

Bacterial serine protease HtrA as a promising new target for antimicrobial therapy?

Recent studies have demonstrated that the bacterial chaperone and serine protease high temperature requirement A (HtrA) is closely associated with the establishment and progression of several infectious diseases. HtrA activity enhances bacterial survival under stress conditions, but also has direct effects on functions of the cell adhesion protein E-cadherin and extracellular ...

Correction: Induction of TLR-2 and TLR-5 Expression by Helicobacter pylori Switches cagPAI-Dependent Signalling Leading to the Secretion of IL-8 and TNF-α

Sabine Brandt Joseph Madassery Steffen Backert - In Panel A of Fig 6, the blot images for the GAPDH lanes in the HEK293-TLR2 and HEK293-TLR5 panels were erroneously duplicated. Please see Figs 10 and 11

DNA transfer in the gastric pathogen Helicobacter pylori

Esther Fernandez-Gonzalez 0 Steffen Backert 0 0 E. Fernandez-Gonzalez S. Backert (&) Division of Microbiology, Department of Biology, Friedrich Alexander University Erlangen/Nuremberg , Staudtstr. 5

Electron Microscopic, Genetic and Protein Expression Analyses of Helicobacter acinonychis Strains from a Bengal Tiger

Colonization by Helicobacter species is commonly noted in many mammals. These infections often remain unrecognized, but can cause severe health complications or more subtle host immune perturbations. The aim of this study was to isolate and characterize putative novel Helicobacter spp. from Bengal tigers in Thailand. Morphological investigation (Gram-staining and electron ...

Helicobacter pylori CagL Y58/E59 Mutation Turns-Off Type IV Secretion-Dependent Delivery of CagA into Host Cells

The type IV secretion system (T4SS) is a major virulence determinant of the gastric pathogen Helicobacter pylori. The CagL protein is a specialized adhesin of the corresponding T4SS pilus, which establishes initial contact with the integrin β1 receptor on host target cells. Recent studies proposed that Y58 and E59 amino acid polymorphisms in CagL increase the virulence of H. pylori ...

Helicobacter pylori HopH (OipA) and Bacterial Pathogenicity: Genetic and Functional Genomic Analysis of hopH Gene Polymorphisms

BackgroundExpression of the Helicobacter pylori outer membrane protein HopH is regulated by phase variation within a CT dinucleotide repeat motif of the hopH gene MethodsTo investigate the importance of HopH for bacterial pathogenicity, we performed a detailed functional genomic and population-based genetic characterization of this contingency locus ResultsSequencing of hopH in H. ...

Induction of TLR-2 and TLR-5 Expression by Helicobacter pylori Switches cagPAI-Dependent Signalling Leading to the Secretion of IL-8 and TNF-α

Helicobacter pylori is the causative agent for developing gastritis, gastric ulcer, and even gastric cancer. Virulent strains carry the cag pathogenicity island (cagPAI) encoding a type-IV secretion system (T4SS) for injecting the CagA protein. However, mechanisms of sensing this pathogen through Toll-like receptors (TLRs) and downstream signalling pathways in the development of ...

Microtubules as Platforms for Assaying Actin Polymerization In Vivo

The actin cytoskeleton is continuously remodeled through cycles of actin filament assembly and disassembly. Filaments are born through nucleation and shaped into supramolecular structures with various essential functions. These range from contractile and protrusive assemblies in muscle and non-muscle cells to actin filament comets propelling vesicles or pathogens through the ...

Molecular mechanisms of gastric epithelial cell adhesion and injection of CagA by Helicobacter pylori

Helicobacter pylori is a highly successful pathogen uniquely adapted to colonize humans. Gastric infections with this bacterium can induce pathology ranging from chronic gastritis and peptic ulcers to gastric cancer. More virulent H. pylori isolates harbour numerous well-known adhesins (BabA/B, SabA, AlpA/B, OipA and HopZ) and the cag (cytotoxin-associated genes) pathogenicity ...

Systematic Analysis of Phosphotyrosine Antibodies Recognizing Single Phosphorylated EPIYA-Motifs in CagA of Western-Type Helicobacter pylori Strains

The clinical outcome of Helicobacter pylori infections is determined by multiple host-pathogen interactions that may develop to chronic gastritis, and sometimes peptic ulcers or gastric cancer. Highly virulent strains encode a type IV secretion system (T4SS) that delivers the effector protein CagA into gastric epithelial cells. Translocated CagA undergoes tyrosine phosphorylation ...

Systematic analysis of phosphotyrosine antibodies recognizing single phosphorylated EPIYA-motifs in CagA of East Asian-type Helicobacter pylori strains

Background Highly virulent strains of the gastric pathogen Helicobacter pylori encode a type IV secretion system (T4SS) that delivers the effector protein CagA into gastric epithelial cells. Translocated CagA undergoes tyrosine phosphorylation by members of the oncogenic c-Src and c-Abl host kinases at EPIYA-sequence motifs A, B and D in East Asian-type strains. These ...

The functional interplay of Helicobacter pylori factors with gastric epithelial cells induces a multi-step process in pathogenesis

Infections with the human pathogen Helicobacter pylori (H. pylori) can lead to severe gastric diseases ranging from chronic gastritis and ulceration to neoplastic changes in the stomach. Development and progress of H. pylori-associated disorders are determined by multifarious bacterial factors. Many of them interact directly with host cells or require specific receptors, while ...

The signaling pathway of Campylobacter jejuni-induced Cdc42 activation: Role of fibronectin, integrin beta1, tyrosine kinases and guanine exchange factor Vav2

Background Host cell invasion by the foodborne pathogen Campylobacter jejuni is considered as one of the primary reasons of gut tissue damage, however, mechanisms and key factors involved in this process are widely unclear. It was reported that small Rho GTPases, including Cdc42, are activated and play a role during invasion, but the involved signaling cascades remained unknown. ...

Transmigration route of Campylobacter jejuni across polarized intestinal epithelial cells: paracellular, transcellular or both?

Intact intercellular junctions and cellular matrix contacts are crucial structural components for the formation and maintenance of epithelial barrier functions in humans to control the commensal flora and protect against intruding microbes. Campylobacter jejuni is one of the most important zoonotic pathogens causing food-borne gastroenteritis and potentially more severe diseases ...

Unique Features of the Mitochondrial Rolling Circle-Plasmid mp1 from the Higher Plant Chenopodium Album (L.)

We analyzed the structure and replication of the mitochondrial (mt) circular DNA plasmid mpl (1309 bp) from the higher plant Chenopodium album (L.). Two dimensional gel electrophoresis (2DE) revealed the existence of oligomers of up to a decamer in addition to the prevailing monomeric form. The migration behavior of cut replication intermediates during 2DE was consistent with a ...