The Relationship between H. pylori Virulence Genotypes and Gastric Diseases

Abstract
There have been no reports on the relationship between virulence genes and gastric diseases based on the same bacterial colonization density. Our results indicated that Helicobacter pylori virulence genes were more relevant than colonization density as a pathogenic mechanism of gastric diseases, which helps elucidate the pathogenic mechanisms of bacteria and aids in the development of improved strategies for the treatment of gastric disease.
    • "H. pylori is known as the main cause of chronic gastritis and is related to peptic ulcers and gastric cancer [2]. Although half of the world's population is infected with this bacterium, most of those infected are asymptomatic and 15%-20% of infected people develop the related diseases [3]. The most common treatment for H. pylori is triple therapy including the combination of two antibiotics (clarithromycin plus amoxicillin or metronidazole) with a proton pump inhibitor [4]. "
    [Show abstract] [Hide abstract] ABSTRACT: The common triple therapy for Helicobacter pylori is challenged by the increasing cases of antibiotic resistant infections, raising the need to explore alternative therapies. Oral administration of egg yolk immunoglobulin Y (IgY) has been previously reported as a means of passive immunization therapy for H. pylori infections. In this work, we investigated the inhibitory effect of IgY on the attachment of H. pylori to AGS cell line. Recombinant OipA was prepared. Hens were immunized with recombinant protein three times. IgY was purified from egg yolks of immunized hens using polyethylene glycol precipitation method. The inhibitory effect of the specific immunoglobulin was evaluated in AGS cell line infected with H. pylori. The presence of recombinant OipA (30 kD) was confirmed via sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Immunization of hens was confirmed using enzyme-linked immunosorbent assay. The purified IgY from egg yolks were assessed using SDS-PAGE and confirmed by western blot. The results showed that IgY-OipA had inhibitory effect on attachment of H. pylori to AGS cell line and may be utilized as a therapeutic or prophylaxis material.
    Full-text · Article · Jul 2015
    • "Helicobacter pylori is a gram-negative bacterium that colonizes the gastric antrum and/or the body of the human stomach, causing complications such as gastritis, gastric and duodenal ulcer and gastric malignancies [1,2]. H. pylori is present in approximately half of the world population [3]. "
    [Show abstract] [Hide abstract] ABSTRACT: Epidemiological investigations have indicated that Helicobacter pylori induces inflammation in the gastric mucosa regulated by several interleukins. The genes IL1B and IL8 are suggested as key factors in determining the risk of gastritis. The aim of this paper was to evaluate the association of gene polymorphism of interleukin-1 and interleukin-8 with chronic gastrits in H. pylori infected patients. A total of 60 patients underwent endoscopic procedure. Biopsy samples were collected for urease test, histopathological and molecular exams. The DNA of theses samples was extracted for detection of H. pylori and analysis of the genes mentioned above. Patients with gastritis had a higher frequency of H. pylori-positive samples. H. pylori was detected in 30/60 patients (50%) by PCR. As for polymorphism of interleukin 8 (-251) gene we observed a statistical difference when analyzed TA (p = 0.039) and TT (p = 0.047) genotypes. In the IL1B31 there was a statistical difference in TT (p = 0.01) genotype and in the IL1B-511 there wasn't any statistical difference. Our results suggest a strong correlation between the presence of chronic gastritis and infection by H. pylori and that IL1B-31TT and IL8-251TT genotypes appear to act as protective factors against H. pylori infection while IL8-251TA genotype may comprise a risk factor for infection with this bacterium.
    Full-text · Article · Apr 2014
    • "In addition, several authors report that the chronic infection may induce gastritis, peptic ulcer, gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue lymphoma345. It is interesting to note that only approximately 20% of H. pylori-infected individuals develop severe gastric diseases , suggesting that clinical outcomes are determined by the interaction among bacterial virulence, host genetic susceptibility and environmental factors [2,6]. Virulence factors of H. pylori – including vacA, cagA and babA – play important roles in gastric diseases. "
    [Show abstract] [Hide abstract] ABSTRACT: Only a few Helicobacter pylori-infected individuals develop severe gastric diseases and virulence factors of H. pylori appear to be involved in such clinical outcomes. Duodenal ulcer promoting gene A (dupA) is a novel virulence factor of Helicobacter pylori that is associated with duodenal ulcer development and reduced risk for gastric carcinoma in some populations. The aims of the present study were to determine the presence of dupA gene and evaluate the association among dupA and other virulence factors including cagA and vacA in Brazilian patients. Gastric biopsies were obtained from 205 dyspeptic patients (100 children and 105 adults). DNA was extracted and analyzed for the presence of H. pylori and its virulence factors using the polymerase chain reaction method. Patients with gastritis tested positive for H. pylori more frequently. The dupA gene was detected in 41.5% of them (85/205); cagA gene was found in 98 isolates (47.8%) and vacA genotype s1/m1 in 50.2%, s1/m2 in 8.3%, s2/m2 in 36.6%, s2/m1 in 0.5% and s1/s2/m1/m2 in 4.4%. We also verified a significant association between cagA and dupA genes [p = 0.0003, relative risk (RR) 1.73 and confidence interval [CI] = 1.3-2.3]. The genotypes s1/m1 were also associated with dupA gene (p = 0.0001, RR: 1.72 and CI: 1.3-2.2). The same associations were found when analyzing pediatric and adult groups of patients individually. Ours results suggest that dupA is highly frequent in Brazilian patients and is associated with cagA gene and vacA s1/m1 genotype, and it may be considered an important virulence factor in the development of gastric diseases in adults or children.
    Full-text · Article · Jan 2014
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