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Toxins Mar 2017colonizes the human stomach and induces inflammation, and in some cases persistent infection can result in gastric cancer. Attachment to the gastric mucosa is the first... (Review)
Review
colonizes the human stomach and induces inflammation, and in some cases persistent infection can result in gastric cancer. Attachment to the gastric mucosa is the first step in establishing bacterial colonization, and outer membrane proteins (OMPs) play a pivotal role in binding to human cells. Some OMP interaction molecules are known in , and their associated host cell responses have been gradually clarified. Many studies have demonstrated that OMPs are essential to CagA translocation into gastric cells via the Type IV secretion system of . This review summarizes the mechanisms through which utilizes OMPs to colonize the human stomach and how OMPs cooperate with the Type IV secretion system.
Topics: Animals; Bacterial Outer Membrane Proteins; Helicobacter pylori; Humans; Virulence Factors
PubMed: 28287480
DOI: 10.3390/toxins9030101 -
Current Microbiology Jul 2017This review aimed to investigate the role of Helicobacter pylori flagella on the pathogenicity of this bacterium in humans. Helicobacter pylori is a flagellated... (Review)
Review
This review aimed to investigate the role of Helicobacter pylori flagella on the pathogenicity of this bacterium in humans. Helicobacter pylori is a flagellated pathogen that colonizes the human gastroduodenal mucosa and produces inflammation, and is responsible for gastrointestinal disease. Its pathogenesis is attributed to colonization and virulence factors. The primary function of H. pylori flagella is to provide motility. We believe that H. pylori flagella play an important role in the colonization of the gastrointestinal mucosa. Therefore, we reviewed previous studies on flagellar morphology and motility in order to explore the relationship between H. pylori flagella and pathogenicity. Further investigation is required to confirm the association between flagella and pathogenicity in H. pylori.
Topics: Animals; Bacterial Proteins; Flagella; Gastric Mucosa; Gene Expression Regulation, Bacterial; Helicobacter Infections; Helicobacter pylori; Humans
PubMed: 28444418
DOI: 10.1007/s00284-017-1256-4 -
BioMed Research International 2015Bacterial biofilms are communities of microorganisms attached to a surface. Biofilm formation is critical not only for environmental survival but also for successful... (Review)
Review
Bacterial biofilms are communities of microorganisms attached to a surface. Biofilm formation is critical not only for environmental survival but also for successful infection. Helicobacter pylori is one of the most common causes of bacterial infection in humans. Some studies demonstrated that this microorganism has biofilm forming ability in the environment and on human gastric mucosa epithelium as well as on in vitro abiotic surfaces. In the environment, H. pylori could be embedded in drinking water biofilms through water distribution system in developed and developing countries so that the drinking water may serve as a reservoir for H. pylori infection. In the human stomach, H. pylori forms biofilms on the surface of gastric mucosa, suggesting one possible explanation for eradication therapy failure. Finally, based on the results of in vitro analyses, H. pylori biofilm formation can decrease susceptibility to antibiotics and H. pylori antibiotic resistance mutations are more frequently generated in biofilms than in planktonic cells. These observations indicated that H. pylori biofilm formation may play an important role in preventing and controlling H. pylori infections. Therefore, investigation of H. pylori biofilm formation could be effective in elucidating the detailed mechanisms of infection and colonization by this microorganism.
Topics: Anti-Bacterial Agents; Bacterial Adhesion; Biofilms; Drug Resistance, Microbial; Helicobacter Infections; Helicobacter pylori; Humans; Stomach
PubMed: 26078970
DOI: 10.1155/2015/914791 -
Clinical Gastroenterology and... Dec 2018
Topics: Helicobacter Infections; Helicobacter pylori; Humans; United States
PubMed: 30454939
DOI: 10.1016/j.cgh.2018.08.035 -
Clinical Gastroenterology and... Dec 2018
Topics: Helicobacter Infections; Helicobacter pylori; Humans; United States
PubMed: 30454938
DOI: 10.1016/j.cgh.2018.08.031 -
Arquivos Brasileiros de Cardiologia Oct 2021
Topics: Helicobacter pylori; Humans; Hypertension
PubMed: 34709290
DOI: 10.36660/abc.20210629 -
International Journal of Environmental... Sep 2022is a Gram-negative bacterium from the family and genus . The pathogen is a causative agent of gastroenteritis, cellulitis, and bacteremia. The increasing antibiotic...
is a Gram-negative bacterium from the family and genus . The pathogen is a causative agent of gastroenteritis, cellulitis, and bacteremia. The increasing antibiotic resistance pattern of the pathogen prompts the efforts to develop a vaccine to prevent dissemination of the bacteria and stop the spread of antibiotic resistance (AR) determinants. Herein, a pan-genome analysis of the pathogen strains was performed to shed light on its core genome and its exploration for potential vaccine targets. In total, four vaccine candidates (TonB dependent receptor, flagellar hook protein FlgE, Hcp family type VI secretion system effector, flagellar motor protein MotB) were identified as promising vaccine candidates and subsequently subjected to an epitopes' mapping phase. These vaccine candidates are part of the pathogen core genome: they are essential, localized at the pathogen surface, and are antigenic. Immunoinformatics was further applied on the selected vaccine proteins to predict potential antigenic, non-allergic, non-toxic, virulent, and DRB*0101 epitopes. The selected epitopes were then fused using linkers to structure a multi-epitopes' vaccine construct. Molecular docking simulations were conducted to determine a designed vaccine binding stability with TLR5 innate immune receptor. Further, binding free energy by MMGB/PBSA and WaterSwap was employed to examine atomic level interaction energies. The designed vaccine also stimulated strong humoral and cellular immune responses as well as interferon and cytokines' production. In a nutshell, the designed vaccine is promising in terms of immune responses' stimulation and could be an ideal candidate for experimental analysis due to favorable physicochemical properties.
Topics: Computational Biology; Cytokines; Epitopes, B-Lymphocyte; Epitopes, T-Lymphocyte; Helicobacter; Interferons; Molecular Docking Simulation; Toll-Like Receptor 5; Type VI Secretion Systems; Vaccines
PubMed: 36141842
DOI: 10.3390/ijerph191811579 -
International Journal of Systematic and... Dec 2017Ongoing changes in taxonomic methods, and in the rapid development of the taxonomic structure of species assigned to the Epsilonproteobacteria have lead the...
Minimal standards for describing new species belonging to the families Campylobacteraceae and Helicobacteraceae: Campylobacter, Arcobacter, Helicobacter and Wolinella spp.
Ongoing changes in taxonomic methods, and in the rapid development of the taxonomic structure of species assigned to the Epsilonproteobacteria have lead the International Committee of Systematic Bacteriology Subcommittee on the Taxonomy of Campylobacter and Related Bacteria to discuss significant updates to previous minimal standards for describing new species of Campylobacteraceae and Helicobacteraceae. This paper is the result of these discussions and proposes minimum requirements for the description of new species belonging to the families Campylobacteraceae and Helicobacteraceae, thus including species in Campylobacter, Arcobacter, Helicobacter, and Wolinella. The core underlying principle remains the use of appropriate phenotypic and genotypic methods to characterise strains sufficiently so as to effectively and unambiguously determine their taxonomic position in these families, and provide adequate means by which the new taxon can be distinguished from extant species and subspecies. This polyphasic taxonomic approach demands the use of appropriate reference data for comparison to ensure the novelty of proposed new taxa, and the recommended study of at least five strains to enable species diversity to be assessed. Methodological approaches for phenotypic and genotypic (including whole-genome sequence comparisons) characterisation are recommended.
Topics: Arcobacter; Bacterial Typing Techniques; Campylobacter; Campylobacteraceae; Helicobacter; Helicobacteraceae; Wolinella
PubMed: 29034857
DOI: 10.1099/ijsem.0.002255 -
Helicobacter Dec 2016This review covers the current knowledge and gaps in Helicobacter pylori lipopolysaccharide (LPS) structure and biosynthesis. H. pylori is a Gram-negative bacterium... (Review)
Review
This review covers the current knowledge and gaps in Helicobacter pylori lipopolysaccharide (LPS) structure and biosynthesis. H. pylori is a Gram-negative bacterium which colonizes the luminal surface of the human gastric epithelium. Both a constitutive alteration of the lipid A preventing TLR4 elicitation and host mimicry of the Lewis antigen decorated O-antigen of H. pylori LPS promote immune escape and chronic infection. To date, the complete structure of H. pylori LPS is not available, and the proposed model is a linear arrangement composed of the inner core defined as the hexa-saccharide (Kdo-LD-Hep-LD-Hep-DD-Hep-Gal-Glc), the outer core composed of a conserved trisaccharide (-GlcNAc-Fuc-DD-Hep-) linked to the third heptose of the inner core, the glucan, the heptan and a variable O-antigen, generally consisting of a poly-LacNAc decorated with Lewis antigens. Although the glycosyltransferases (GTs) responsible for the biosynthesis of the H. pylori O-antigen chains have been identified and characterized, there are many gaps in regard to the biosynthesis of the core LPS. These limitations warrant additional mutagenesis and structural studies to obtain the complete LPS structure and corresponding biosynthetic pathway of this important gastric bacterium.
Topics: Glycosyltransferases; Helicobacter pylori; Humans; Immune Evasion; Lipopolysaccharides; Metabolic Networks and Pathways
PubMed: 26934862
DOI: 10.1111/hel.12301 -
Cellular and Molecular Gastroenterology... 2024
Topics: Nuclear Proteins; Helicobacter pylori; Transcription Factors; Macrophages; Cell Line
PubMed: 38016647
DOI: 10.1016/j.jcmgh.2023.11.008