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The Korean Journal of Gastroenterology... Nov 2018Accurate diagnosis of infection is mandatory for the effective management of many gastroduodenal diseases. Currently, various diagnostic methods are available for... (Review)
Review
Accurate diagnosis of infection is mandatory for the effective management of many gastroduodenal diseases. Currently, various diagnostic methods are available for detecting these infections, and the choice of method should take into account the clinical condition, accessibility, advantage, disadvantage, as well as cost-effectiveness. The diagnostic methods are divided into invasive (endoscopic-based) and non-invasive methods. Non-invasive methods included urea breath test, stool antigen test, serology, and molecular methods. Invasive methods included endoscopic imaging, rapid urease test, histology, culture, and molecular methods. In this article, we provide a review of the currently available options and recent advances of various diagnostic methods.
Topics: Antigens, Bacterial; Breath Tests; DNA, Bacterial; Feces; Gastroscopy; Helicobacter Infections; Helicobacter pylori; Humans
PubMed: 30642138
DOI: 10.4166/kjg.2018.72.5.229 -
World Journal of Gastroenterology May 2014Helicobacter pylori (H. pylori) infection is highly associated with the occurrence of gastrointestinal diseases, including gastric inflammation, peptic ulcer, gastric... (Review)
Review
Helicobacter pylori (H. pylori) infection is highly associated with the occurrence of gastrointestinal diseases, including gastric inflammation, peptic ulcer, gastric cancer, and gastric mucosa-associated lymphoid-tissue lymphoma. Although alternative therapies, including phytomedicines and probiotics, have been used to improve eradication, current treatment still relies on a combination of antimicrobial agents, such as amoxicillin, clarithromycin, metronidazole, and levofloxacin, and antisecretory agents, such as proton pump inhibitors (PPIs). A standard triple therapy consisting of a PPI and two antibiotics (clarithromycin and amoxicillin/metronidazole) is widely used as the first-line regimen for treatment of infection, but the increased resistance of H. pylori to clarithromycin and metronidazole has significantly reduced the eradication rate using this therapy and bismuth-containing therapy or 10-d sequential therapy has therefore been proposed to replace standard triple therapy. Alternatively, levofloxacin-based triple therapy can be used as rescue therapy for H. pylori infection after failure of first-line therapy. The increase in resistance to antibiotics, including levofloxacin, may limit the applicability of such regimens. However, since resistance of H. pylori to amoxicillin is generally low, an optimized high dose dual therapy consisting of a PPI and amoxicillin can be an effective first-line or rescue therapy. In addition, the concomitant use of alternative medicine has the potential to provide additive or synergistic effects against H. pylori infection, though its efficacy needs to be verified in clinical studies.
Topics: Animals; Anti-Bacterial Agents; Complementary Therapies; Drug Administration Schedule; Drug Resistance, Bacterial; Drug Therapy, Combination; Helicobacter Infections; Helicobacter pylori; Humans; Practice Guidelines as Topic; Probiotics; Proton Pump Inhibitors; Time Factors; Treatment Outcome
PubMed: 24833858
DOI: 10.3748/wjg.v20.i18.5283 -
Journal of Cellular and Molecular... Dec 2019Helicobacter pylori (H pylori) is known as one of the most common infectious pathogens, with high infection and recurrence rates worldwide. The prevalence of H pylori... (Review)
Review
Helicobacter pylori (H pylori) is known as one of the most common infectious pathogens, with high infection and recurrence rates worldwide. The prevalence of H pylori is up to 90% in developing countries, while the annual recurrence rate is much higher than that in developed countries. Recurrence can occur either by recrudescence or reinfection. Compared with reinfection, the time window for recrudescence is generally shorter, followed by the recurrence of H pylori-associated diseases in the short-term. Many factors are involved in the H pylori reinfection, such as the prevalence of H pylori infection, living conditions and economic development, health conditions and so forth. Previous studies focused less on H pylori recrudescence. Therefore, the influencing factors for H pylori recrudescence needed further exploration. This study reviewed the recrudescence of H pylori infection and its influencing factors.
Topics: Animals; Developing Countries; Drug Therapy, Combination; Helicobacter Infections; Helicobacter pylori; Humans; Prevalence; Recurrence; Risk Factors
PubMed: 31536675
DOI: 10.1111/jcmm.14682 -
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 -
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 -
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 -
World Journal of Gastroenterology Aug 2014More than 50% of the world population is infected with Helicobacter pylori (H. pylori). The bacterium highly links to peptic ulcer diseases and duodenal ulcer, which was... (Review)
Review
More than 50% of the world population is infected with Helicobacter pylori (H. pylori). The bacterium highly links to peptic ulcer diseases and duodenal ulcer, which was classified as a group I carcinogen in 1994 by the WHO. The pathogenesis of H. pylori is contributed by its virulence factors including urease, flagella, vacuolating cytotoxin A (VacA), cytotoxin-associated gene antigen (Cag A), and others. Of those virulence factors, VacA and CagA play the key roles. Infection with H. pylori vacA-positive strains can lead to vacuolation and apoptosis, whereas infection with cagA-positive strains might result in severe gastric inflammation and gastric cancer. Numerous medicinal plants have been reported for their anti-H. pylori activity, and the relevant active compounds including polyphenols, flavonoids, quinones, coumarins, terpenoids, and alkaloids have been studied. The anti-H. pylori action mechanisms, including inhibition of enzymatic (urease, DNA gyrase, dihydrofolate reductase, N-acetyltransferase, and myeloperoxidase) and adhesive activities, high redox potential, and hydrophilic/hydrophobic natures of compounds, have also been discussed in detail. H. pylori-induced gastric inflammation may progress to superficial gastritis, atrophic gastritis, and finally gastric cancer. Many natural products have anti-H. pylori-induced inflammation activity and the relevant mechanisms include suppression of nuclear factor-κB and mitogen-activated protein kinase pathway activation and inhibition of oxidative stress. Anti-H. pylori induced gastric inflammatory effects of plant products, including quercetin, apigenin, carotenoids-rich algae, tea product, garlic extract, apple peel polyphenol, and finger-root extract, have been documented. In conclusion, many medicinal plant products possess anti-H. pylori activity as well as an anti-H. pylori-induced gastric inflammatory effect. Those plant products have showed great potential as pharmaceutical candidates for H. pylori eradication and H. pylori induced related gastric disease prevention.
Topics: Animals; Anti-Bacterial Agents; Anti-Inflammatory Agents; Gastritis; Helicobacter Infections; Helicobacter pylori; Humans; Phytotherapy; Plant Preparations; Plants, Medicinal; Treatment Outcome; Virulence; Virulence Factors
PubMed: 25132753
DOI: 10.3748/wjg.v20.i30.10368 -
BioMed Research International 2015
Topics: Animals; Cytokines; Helicobacter Infections; Helicobacter pylori; Humans; Precancerous Conditions
PubMed: 25949992
DOI: 10.1155/2015/304768 -
Arquivos de Gastroenterologia 2018
Topics: Helicobacter Infections; Helicobacter pylori; Humans; Stomach Diseases
PubMed: 30043875
DOI: 10.1590/S0004-2803.201800000-37 -
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