scholarly journals Expanding Allelic Diversity of Helicobacter pylori vacA

1998 ◽  
Vol 36 (9) ◽  
pp. 2597-2603 ◽  
Author(s):  
Leen-Jan van Doorn ◽  
Céu Figueiredo ◽  
Ricardo Sanna ◽  
Salvador Pena ◽  
Peter Midolo ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Direct Sequencing ◽  
Allelic Diversity ◽  
Pcr Primers ◽  
Epidemiological Studies ◽  
Sequence Alignments ◽  
Gene Encoding ◽  
The World ◽  
Probe Assay ◽  
H Pylori

The diversity of the gene encoding the vacuolating cytotoxin (vacA) of Helicobacter pylori was analyzed in 98 isolates obtained from different geographic locations. The studies focused on variation in the previously defined s and m regions ofvacA, as determined by PCR and direct sequencing. Phylogenetic analysis revealed the existence of four distinct types of s-region alleles: aside from the previously described s1a, s1b, and s2 allelic types, a novel subtype, designated s1c, was found. Subtype s1c was observed exclusively in isolates from East Asia and appears to be the major s1 allele in that part of the world. Three different allelic forms (m1, m2a, and m2b) were detected in the m region. On the basis of sequence alignments, universal PCR primers that allow effective amplification of the s and m regions from H. pyloriisolates from all over the world were defined. Amplimers were subsequently analyzed by reverse hybridization onto a line probe assay (LiPA) that allows the simultaneous and highly specific hybridization of the different vacA s- and m-region alleles and tests for the presence of the cytotoxin-associated gene (cagA). This PCR-LiPA method permits rapid analysis of the vacA andcagA status of H. pylori strains for clinical and epidemiological studies and will facilitate identification of any further variations.

scholarly journals Typing of Helicobacter pylori vacA Gene and Detection of cagA Gene by PCR and Reverse Hybridization

1998 ◽  
Vol 36 (5) ◽  
pp. 1271-1276 ◽  
Author(s):  
L. J. van Doorn ◽  
C. Figueiredo ◽  
R. Rossau ◽  
G. Jannes ◽  
M. van Asbroeck ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Present Report ◽  
Pcr Primers ◽  
Single Step ◽  
Reverse Hybridization ◽  
Dutch Patient ◽  
Probe Assay ◽  
Vaca Gene ◽  
H Pylori ◽  
Multiple Strains

The present report describes an analysis of two virulence genes ofHelicobacter pylori. Parts of the cagA gene, as well as parts from the signal (s) and middle (m) regions of the mosaicvacA gene, were amplified with biotin-labelled PCR primers and the products were subsequently analyzed by a single-step reverse hybridization line probe assay (LiPA). This assay comprises a strip containing multiple specific probes for the vacA s region (s1a, s1b, and s2 alleles), the vacA m region (m1 and m2 alleles), and the cagA gene. A total of 103 H. pylori-positive materials, including cultured isolates, gastric biopsy specimens, and surgical specimens from patients living in Portugal (n = 55) and The Netherlands (n = 48) were tested by the PCR-LiPA. cagAwas detected in 84 and 73% of the Portuguese and Dutch patients, respectively. vacA typing results, as determined by reverse hybridization, were completely concordant with those of sequence analysis. Most Portuguese patients (72%) contained type s1b, whereas most Dutch patients (61%) contained type s1a (P < 0.001). The method is also very effective at detecting the presence of multiple genotypes in a single biopsy specimen. The prevalence of multiple strains in Portuguese patient samples was significantly higher (29%) than that in Dutch patient samples (8%) (P = 0.001). There was a significant association between the presence of ulcers or gastric carcinoma and the presence of vacA type s1 (s1a or s1b; P = 0.008) and cagA(P = 0.003) genes.

scholarly journals Methylation status of CDH1 gene in samples of gastric mucous from brazilian patients with chronic gastritis infected by Helicobacter pylori

2010 ◽  
Vol 47 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Erika Kague ◽  
Cristiane Melissa Thomazini ◽  
Maria Inês de Campo Moura Pardini ◽  
Fabrício de Carvalho ◽  
Celso Vieira Leite ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Tumor Suppressor ◽  
Chronic Gastritis ◽  
Direct Sequencing ◽  
Methylation Status ◽  
Cpg Islands ◽  
Pcr Primers ◽  
Suppressor Gene ◽  
Cdh1 Gene ◽  
H Pylori

CONTEXT: Gastric cancer is one of the top list of cancer types that most leads to death in Brazil and worldwide. Helicobacter pylori(H. pylori) is a class I carcinogen and infect almost 90% of chronic gastritis patients. Some genotypes confer different virulent potential to H. pylori and can increase the risk of gastritis development. Methylation of CpG islands can inactivate tumor suppressor genes and therefore, it can be involved in the tumorigenic process. CDH1 is a tumor suppressor gene that encodes the E-cadherin protein, which is important in maintaining cell-cell contacts. The inactivation of this gene can increase the chance of metastasis. Promoter methylation of CDH1 at early steps of gastric carcinogenesis is not yet completely understood. OBJECTIVE: In this study, we investigated the methylation status of CDH1 in chronic gastritis samples and correlated it with the presence of H. pylori. METHODS: Sixty gastric mucosal biopsies were used in this study. The detection of H. pylori was performed with the PCR primers specific to urease C gene. H. pylori genotyping was performed by PCR to cagA and vacA (s and m region). The methylation status of these gene CDH1 was analyzed using methylation-specific polymerase chain reaction and direct sequencing of the PCR products was performed using primers methylated and unmethylated in both forward and reverse directions. RESULTS: H. pylori was detected in 90% of chronic gastritis samples; among these 33% were cagA positive and 100% vacA s1. The genotype vacA s2/m1 was not detected in any sample analyzed. Methylation of CDH1 was detected in 63.3% of chronic gastritis samples and 95% of them were also H. pylori-positive. CONCLUSION: This work suggests that CDH1 gene methylation and H. pylori infection are frequent events in samples from Brazilian patients with chronic gastritis and reinforces the correlation between H. pylori infection and CDH1 inactivation in early steps of gastric tumorigenesis.

scholarly journals RESISTANCE TO AMOXICILLIN, CLARITHROMYCIN AND CIPROFLOXACIN OF Helicobacter pylori ISOLATED FROM SOUTHERN BRAZIL PATIENTS

2014 ◽  
Vol 56 (3) ◽  
pp. 197-200 ◽  
Author(s):  
Simone Ulrich Picoli ◽  
Luiz Edmundo Mazzoleni ◽  
Heriberto Fernández ◽  
Laura Renata De Bona ◽  
Erli Neuhauss ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Eradication Therapy ◽  
Empirical Therapy ◽  
British Society ◽  
World Population ◽  
Southern Brazil ◽  
First Line ◽  
The World ◽  
Antibiotics Susceptibility ◽  
H Pylori

Introduction: Helicobacter pylori is a bacteria which infects half the world population and is an important cause of gastric cancer. The eradication therapy is not always effective because resistance to antimicrobials may occur. The aim of this study was to determine the susceptibility profile of H. pylori to amoxicillin, clarithromycin and ciprofloxacin in the population of Southern Brazil. Material and methods: Fifty four samples of H. pylori were evaluated. The antibiotics susceptibility was determined according to the guidelines of the British Society for Antimicrobial Chemotherapy and the Comité de l'Antibiogramme de la Société Française de Microbiologie. Results: Six (11.1%) H. pylori isolates were resistant to clarithromycin, one (1.9%) to amoxicillin and three (5.5%) to ciprofloxacin. These indices of resistance are considered satisfactory and show that all of these antibiotics can be used in the empirical therapy. Conclusion: The antibiotics amoxicillin and clarithromycin are still a good option for first line anti-H. pylori treatment in the population of Southern Brazil.

scholarly journals Cloning, sequencing, expression, purification and preliminary characterization of a type II dehydroquinase from Helicobacter pylori

1996 ◽  
Vol 319 (2) ◽  
pp. 559-565 ◽  
Author(s):  
Joanna R BOTTOMLEY ◽  
Christopher L. CLAYTON ◽  
Peter A. CHALK ◽  
Colin KLEANTHOUS
Keyword(s):  
Helicobacter Pylori ◽  
Sequence Data ◽  
Shikimate Pathway ◽  
Cosmid Library ◽  
Type Ii ◽  
Gene Encoding ◽  
Heat Stable ◽  
Plasmid Construct ◽  
H Pylori ◽  
Type Ii Dehydroquinase

A heat-stable dehydroquinase was purified to near homogeneity from a plate-grown suspension of the Gram-negative stomach pathogen Helicobacter pylori, and shown from both its subunit and native molecular masses to be a member of the type II family of dehydroquinases. This was confirmed by N-terminal amino acid sequence data. The gene encoding this activity was isolated following initial identification, by random sequencing of the H. pylori genome, of a 96 bp fragment, the translated sequence of which showed strong identity to a C-terminal region of other type II enzymes. Southern blot analysis of a cosmid library identified several potential clones, one of which complemented an Escherichia coliaroD point mutant strain deficient in host dehydroquinase. The gene encoding the H. pylori type II dehydroquinase (designated aroQ) was sequenced. The translated sequence was identical to the N-terminal sequence obtained directly from the purified protein, and showed strong identity to other members of the type II family of dehydroquinases. The enzyme was readily expressed in E. coli from a plasmid construct from which several milligrams of protein could be isolated, and the molecular mass of the protein was confirmed by electrospray MS. The aroQ gene in H. pylori may function in the central biosynthetic shikimate pathway of this bacterium, thus opening the way for the construction of attenuated strains as potential vaccines as well as offering a new target for selective enzyme inhibition.

scholarly journals Treatment of Helicobacter pylori infections in the light of the increase of antibiotic resistance

2018 ◽  
Vol 72 ◽  
pp. 143-158
Author(s):  
Eliza Mnich ◽  
Jakub Ibran ◽  
Magdalena Chmiela
Keyword(s):  
Fatty Acids ◽  
Ascorbic Acid ◽  
Helicobacter Pylori ◽  
Antibiotic Resistance ◽  
Eradication Therapy ◽  
The World ◽  
Potential Alternative ◽  
Resistant Strains ◽  
Treatment Mechanisms ◽  
H Pylori

The aim of this study was to present the risks associated with the occurrence of Helicobacter pylori (H. pylori) infection in humans and the problems related to eradication procedures with the use of antibiotic treatment. The content provides an overview of the available methods of infection diagnosis and recommended therapeutic schemes as well as potential alternative schedules of treatment. Mechanisms of H. pylori resistance to commonly used antibiotics including the mutations in the genome leading to resistance and the incidence of resistant strains in the world has been described. Finally, we introduced substances with some potential in eradication therapy, including probiotics, plant formulations as well as polyunsaturated fatty acids and ascorbic acid.

scholarly journals Biological characteristics and virulence of Helicobacter pylori

2018 ◽  
Vol 20 (1) ◽  
pp. 14-23 ◽  
Author(s):  
G.Sh. Isaeva ◽  
R.I. Valieva
Keyword(s):  
Helicobacter Pylori ◽  
Clinical Outcomes ◽  
Genetic Heterogeneity ◽  
Biofilm Formation ◽  
Clinical Manifestations ◽  
Epidemiological Studies ◽  
Biological Characteristics ◽  
Pathogenicity Factors ◽  
H Pylori

This review summarizes the most recent data on the biological characteristics of Helicobacter pylori (morphological, cultural, biochemical). H. pylori pathogenicity factors promoting colonization, adhesion, biofilm formation, aggression, and cytotoxicity, their contribution to the pathogenesis of diseases as well as the possible relationships with various clinical outcomes are described in detail. The genetic heterogeneity of H. pylori strains which can determine different clinical manifestations and have significance for conducting epidemiological studies is also considered.

scholarly journals Investigating the Efficacy of Triple Drug Therapy and Sequential Drug Therapy in the Eradication of Helicobacter Pylori with Respect to Antigen Stool test: A Pilot Study

2020 ◽  
Vol 18 (1) ◽  
pp. 74-83
Author(s):  
R. Shrestha ◽  
R. Poudel ◽  
S. Shakya ◽  
R.B. Gurung ◽  
R. Makaju ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Drug Therapy ◽  
Sequential Therapy ◽  
Drug Regimen ◽  
Epidemiological Studies ◽  
Response To Treatment ◽  
Antigen Test ◽  
Stool Antigen Test ◽  
Stool Antigen ◽  
H Pylori

Background Helicobacter pylori is one of the most prevalent infectious disease worldwide. The treatment regimens involve mainly two therapies: Standard Triple drug therapy and Sequential drug therapy. Several studies have shown that the sequential therapy has higher eradication rates of H. pylori than the standard triple drug therapy and since proper study on sequential drug therapy and standard triple drug therapy is still lacking in Nepal, this study is attempted to compare efficacy of Sequential Drug Therapy in the eradication of H. pylori in gastritis with respect to the Standard triple drug therapy. Objective To investigate the efficacy of Triple Drug Therapy and Sequential Drug Therapy in the eradication of Helicobacter pylori with respect to Antigen Stool test. Method This study was the prospective study conducted in 62 patients attending the Department of Gastroenterology, Dhulikhel Hospital, meeting the inclusion criteria who were confirmed as H. pylori positive by histopathology and stool antigen test. Patients were randomized into two groups. One group prescribed with Standard triple drug regimen and another group with Sequential drug regimen. Eradication of H. pylori infection was confirmed by repeating the stool antigen test at least five weeks after the completion of the regimen. Result Among the 62 participants included in this study, 54.5% of them were males. Among the study population, the eradication achieved by standard triple drug therapy was 87.8% and 89.6% with Sequential drug therapy. Higher numbers (82.3%) of patients were compliant to the prescribed medication. Forgetfulness was the main reason for missing the dose (91%) of the non-compliant patients. Conclusion The study revealed an equal efficacy of both Standard Triple drug regimen and Sequential drug regimen in the eradication of H. pylori infection. Further, Stool antigen test can be preferred as a non-invasive test, for diagnosis of H. pylori infection, monitoring the response to treatment and in epidemiological studies.

scholarly journals Effect of Helicobacter pylori infection on the course of nonalcoholic fatty liver disease

2019 ◽  
pp. 90-94
Author(s):  
L. B. Lazebnik ◽  
L. V. Tarasova ◽  
E. A. Komarova ◽  
E. I. Busalayeva
Keyword(s):  
Helicobacter Pylori ◽  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
Helicobacter Pylori Infection ◽  
Course Of Disease ◽  
Nonalcoholic Fatty Liver ◽  
The World ◽  
H Pylori

The prevalence of nonalcoholic fatty liver disease (NAFLD) in the world steadily increasеs, turning it into a most prevalent liver disease in the last decade. NAFLD is a multidisciplinary problem, it attracts the attention of specialists of different specialities. Especially interesting is the clarification of the main links of the pathogenesis of nonalcoholic fatty liver disease, including the effect of endogenous microflora on the occurrence and course of disease. Modern information is represented in the review, it confirm the association between Helicobacter pylori infection (H. pylori) and NAFLD. It has been proven that successful eradication of H. pylori detaines the fibrosis in the liver, reduces the level of proinflammatory markers, and improves insulin resistance.

scholarly journals Curcumin Oxidation Is Required for Inhibition of Helicobacter pylori Growth, Translocation and Phosphorylation of Cag A

2021 ◽  
Vol 11 ◽  
Author(s):  
Ashwini Kumar Ray ◽  
Paula B. Luis ◽  
Surabhi Kirti Mishra ◽  
Daniel P. Barry ◽  
Mohammad Asim ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Growth Inhibition ◽  
Mrna Expression ◽  
Host Protein ◽  
Dependent Manner ◽  
Gene Encoding ◽  
E Coli ◽  
H Pylori

Curcumin is a potential natural remedy for preventing Helicobacter pylori-associated gastric inflammation and cancer. Here, we analyzed the effect of a phospholipid formulation of curcumin on H. pylori growth, translocation and phosphorylation of the virulence factor CagA and host protein kinase Src in vitro and in an in vivo mouse model of H. pylori infection. Growth of H. pylori was inhibited dose-dependently by curcumin in vitro. H. pylori was unable to metabolically reduce curcumin, whereas two enterobacteria, E. coli and Citrobacter rodentium, which efficiently reduced curcumin to the tetra- and hexahydro metabolites, evaded growth inhibition. Oxidative metabolism of curcumin was required for the growth inhibition of H. pylori and the translocation and phosphorylation of CagA and cSrc, since acetal- and diacetal-curcumin that do not undergo oxidative transformation were ineffective. Curcumin attenuated mRNA expression of the H. pylori virulence genes cagE and cagF in a dose-dependent manner and inhibited translocation and phosphorylation of CagA in gastric epithelial cells. H. pylori strains isolated from dietary curcumin-treated mice showed attenuated ability to induce cSrc phosphorylation and the mRNA expression of the gene encoding for IL-8, suggesting long-lasting effects of curcumin on the virulence of H. pylori. Our work provides mechanistic evidence that encourages testing of curcumin as a dietary approach to inhibit the virulence of CagA.

scholarly journals Construction and Characterization of aHelicobacter pylori clpB Mutant and Role of the Gene in the Stress Response

1998 ◽  
Vol 180 (2) ◽  
pp. 426-429 ◽  
Author(s):  
Elaine Allan ◽  
Peter Mullany ◽  
Soad Tabaqchali
Keyword(s):  
Helicobacter Pylori ◽  
High Temperature ◽  
Stress Response ◽  
Structural Features ◽  
High Temperature Stress ◽  
Gene Encoding ◽  
Increased Sensitivity ◽  
H Pylori

ABSTRACT Antiserum raised against whole Helicobacter pyloricells identified a novel 94-kDa antigen. The nucleotide sequence of the gene encoding the 94-kDa antigen was determined, and analysis of the deduced amino acid sequence revealed structural features typical of the ClpB ATPase family of stress response proteins. An isogenic H. pylori clpB mutant showed increased sensitivity to high-temperature stress, indicating that the clpB gene product functions as a stress response protein in H. pylori.

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