Determination of Helicobacter pylori virulence by analysis of the cag pathogenicity island isolated from Iranian patients

Infiltration to infection: key virulence players of Helicobacter pylori pathogenicity

PURPOSE

This study aims to comprehensively review the multifaceted factors underlying the successful colonization and infection process of Helicobacter pylori (H. pylori), a prominent Gram-negative pathogen in humans. The focus is on elucidating the functions, mechanisms, genetic regulation, and potential cross-interactions of these elements.

METHODS

Employing a literature review approach, this study examines the intricate interactions between H. pylori and its host. It delves into virulence factors like VacA, CagA, DupA, Urease, along with phase variable genes, such as babA, babC, hopZ, etc., giving insights about the bacterial perspective of the infection The association of these factors with the infection has also been added in the form of statistical data via Funnel and Forest plots, citing the potential of the virulence and also adding an aspect of geographical biasness to the virulence factors. The biochemical characteristics and clinical relevance of these factors and their effects on host cells are individually examined, both comprehensively and statistically.

RESULTS

H. pylori is a Gram-negative, spiral bacterium that successfully colonises the stomach of more than half of the world's population, causing peptic ulcers, gastric cancer, MALT lymphoma, and other gastro-duodenal disorders. The clinical outcomes of H. pylori infection are influenced by a complex interplay between virulence factors and phase variable genes produced by the infecting strain and the host genetic background. A meta-analysis of the prevalence of all the major virulence factors has also been appended.

CONCLUSION

This study illuminates the diverse elements contributing to H. pylori's colonization and infection. The interplay between virulence factors, phase variable genes, and host genetics determines the outcome of the infection. Despite biochemical insights into many factors, their comprehensive regulation remains an understudied area. By offering a panoramic view of these factors and their functions, this study enhances understanding of the bacterium's perspective, i.e. H. pylori's journey from infiltration to successful establishment within the host's stomach.

Mechanistic research: Selenium regulates virulence factors, reducing adhesion ability and inflammatory damage of Helicobacter pylori

BACKGROUND

The pathogenicity of Helicobacter pylori is dependent on factors including the environment and the host. Although selenium is closely related to pathogenicity as an environmental factor, the specific correlation between them remains unclear.

AIM

To investigate how selenium acts on virulence factors and reduces their toxicity.

METHODS

H. pylori strains were induced by sodium selenite. The expression of cytotoxin-associated protein A (CagA) and vacuolating cytotoxin gene A (VacA) was determined by quantitative PCR and Western blotting. Transcriptomics was used to analyze CagA, CagM, CagE, Cag1, Cag3, and CagT. C57BL/6A mice were infected with the attenuated strains subjected to sodium selenite induction, and H. pylori colonization, inflammatory reactions, and the cell adhesion ability of H. pylori were assessed.

RESULTS

CagA and VacA expression was upregulated at first and then downregulated in the H. pylori strains after sodium selenite treatment. Their expression was significantly and steadily downregulated after the 5th cycle (10 d). Transcriptome analysis revealed that sodium selenite altered the levels affect H. pylori virulence factors such as CagA, CagM, CagE, Cag1, Cag3, and CagT. Of these factors, CagM and CagE expression was continuously downregulated and further downregulated after 2 h of induction with sodium selenite. Moreover, CagT expression was upregulated before the 3rd cycle (6 d) and significantly downregulated after the 5th cycle. Cag1 and Cag3 expression was upregulated and downregulated, respectively, but no significant change was observed by the 5th cycle. C57BL/6A mice were infected with the attenuated strains subjected to sodium selenite induction. The extent of H. pylori colonization in the stomach increased; however, sodium selenite also induced a mild inflammatory reaction in the gastric mucosa of H. pylori-infected mice, and the cell adhesion ability of H. pylori was significantly weakened.

CONCLUSION

These results demonstrate that H. pylori displayed virulence attenuation after the 10th d of sodium selenite treatment. Sodium selenite is a low toxicity compound with strong stability that can reduce the cell adhesion ability of H. pylori, thus mitigating the inflammatory damage to the gastric mucosa.

CagE, cagA and cagA 3' region polymorphism of Helicobacter pylori and their association with the intra-gastric diseases in Moroccan population

Helicobacter pylori infection is the most important etiological factor in gastroduodenal diseases development. Its evolution is influenced by several factors, including bacterial virulence genes such as cagA and cagE. This work aimed to evaluate the predictive value of cagE alone and in combination with cagA and CagA-EPIYA-C motifs number as a marker of the infection evolution. A total of 823 H. pylori DNA extracted from biopsies of consenting patients suffering from gastritis, peptic ulcer, or gastric cancer. The cagE, cagA status and cagA 3' region polymorphism were determined by PCR. The analysis shows that the risk of duodenal ulcer is 1.97-fold higher (CI = 1.18-3.30) in patients infected by strains cagA+/cagE+. And the risk of gastric cancer is 5.19-fold higher (CI = 1.18-22.70) in patients harboring strains cagE+/2EPIYA-C. The results suggest that cagE in combination with cagA-EPIYA-C motifs number can be used as predictive biomarker of H. pylori infection evolution.

Transcriptional Profile of Helicobacter pylori Virulence Genes in Patients with Gastritis and Gastric Cancer

Introduction

Numerous molecular epidemiology studies have been performed about the frequency of Helicobacter pylori virulence genes in patients with H. pylori infection so far. This study was conducted to detect transcriptional profile by cDNA of H. pylori virulence genes in gastric biopsy samples of gastritis and gastric carcinoma patients.

Materials and Methods

In a case-control study, based on the prevalence of gastritis and gastric cancer in Sanandaj city during 2018 and 2019, 23 and 11 gastric antral biopsy samples with H. pylori infection were collected from gastritis and gastric carcinoma patients by the consecutive and available sampling method. Pathological characters, including tumor grades and tumor areas for gastric carcinoma biopsy samples prepared from gastric cancer areas, were determined by the pathologist. Total RNA of gastric antral biopsy samples was extracted, and their cDNA was synthesized by TaKaRa kit. H. pylori virulence genes' cDNA using specific primers and PCR was detected. This study's results were analyzed by SPSS version 25 and statics chi-square tests for determination of relationship and correlation between cDNAs of H. pylori transcriptional profile and clinical outcomes of H. pylori infection, including gastritis, gastric carcinoma, tumor grades, and tumor area.

Results

The positive statistical correlations were observed between transcripts of cagA, cagA-EPIYAC, cagE, and cagY genes and H. pylori infection clinical outcomes (P < 0.05).

Conclusion

Detection of the H. pylori virulence genes' cDNA in gastric biopsy samples can help provide the prognosis of clinical outcomes.

The role of extracellular matrix proteins in gastric cancer development via epithelial-mesenchymal transition

AIM

To acquire a deeper perception of EMT, we evaluated the expression of some candidate extra cellular matrix (ECM) proteins including THBS2, OSMR and CHI3L1 which were collected from RNA-seq bioinformatic analyses.

BACKGROUND

Gastric cancer (GC) is a major incident gastrointestinal cancer with a high rate of mortality. Metastasis is a challenging issue in gastric cancer treatment. Epithelial mesenchymal transition (EMT) of cancer cells is a complicated process controlled by different cells and molecular pathways regarded as an important step at the onset of metastasis.

METHODS

AGS gastric cancer cell line was cultured and treated by TGF-β. EMT induction was verified by measuring the expression of E-cadherin, Snail, β-catenin and Vimentin genes by real time PCR. Then, following our previous study, we evaluated the expression of THBS2, OSMR and CHI3L1 genes in EMT induced cells by real time PCR.

RESULTS

Downregulation of E-cadherin and upregulation of Snail, β-catenin and Vimentin genes were verified in AGS treated cells in comparison with none-treated cells (P-value = 0.0355, P-value = 0.007, P-value = 0.0059, P-value = 0.0206 respectively). Also, upregulation of THBS2, OSMR and CHI3L1 were validated in these cells after EMT induction (P-value = 0.0147, P-value = 0.05, P-value = 0.05 respectively).

CONCLUSION

Our morphological and molecular results validated EMT induction by TGF- β cytokine in AGS gastric cancer cell line. Furthermore, significant upregulation of candidate genes including THBS2, OSMR and CHI3L1 verified the role of these proteins in gastric cancer invasiveness. However, further studies are needed for the validation of prognostic value of these markers.

A new endoscopic submucosal resection -ligation technique for gastric tumors

Although most subepithelial lesions are benign, the malignant forms could present as serious life-threating cancers. Their accurate diagnosis depends on complete surgical resection. Different endoscopic methods have been recommended for the resection. Recently, the EMR has been considered as a safe and effective technique, while various revised EMR techniques have been introduced. In this study, a new version of EMR has been evaluated in two patients. Two middle-aged cases with gastric subepithelial tumors were admitted to Taleghani gastrointestinal department. The polyps were resected via our new Endoscopic Mucosal Resection (EMR) technique. In this technique, the needle knife was used for un-roofing the mucosal surface. Then, the polyps were resected with hot snares. The hemoclips were applied for ligation too. We found no early or delayed complications. Furthermore, the microscopic margins of the lesions were free. Our study represented a safe and cost-beneficial technique for subepithelial lesions and no complications was found and the margins were free. However, further investigations are required for confirming the validity of this new EMR technique.

An algorithmic approach to gastrointestinal bleeding in patients receiving antithrombotic agents

Gastrointestinal bleeding is an overwhelming complication of patients taking antithrombotic agents. These drugs pose a challenge to physicians in the management of bleeding to establish hemostasis without putting these patients at a higher risk for thromboembolism. This study aims to propose an algorithmic approach to four major groups of patients receiving antithrombotic agents (single antiplatelet agents, dual antiplatelet agents, anticoagulants and direct oral anticoagulants) to decide when and how these drugs should be held or restarted to offset between the risk of re-bleeding and thromboembolism. Four case-based algorithms are proposed in this article based on some relevant articles. Having designed four case-based algorithms, we are hoping to guide physicians who face a dilemma on the management of patients receiving antithrombotics when gastrointestinal bleeding occurs. Patients using antithrombotics referred for gastrointestinal bleeding were stratified into four groups based on the medication which is used as an antithrombotic agent and four algorithms were designed which are presented here. We have made an attempt to have a stepwise approach to four cases relevant to the study and have an evaluation on the management of their antithrombotic agents during an episode of gastrointestinal bleeding. It is widely accepted that antithrombotic agents should be restarted as soon as possible after the establishment of hemostasis in a patient taking antithrombotics referring for gastrointestinal bleeding. The time for resuming these drugs is different based on the severity of bleeding, the probability of thromboembolic events, and the nature of the antithrombotic medication which is used by the patient.

Predication of hub target genes of differentially expressed microRNAs contributing to Helicobacter pylori infection in gastric non-cancerous tissue

AIM

The main goal of this investigation was to provide an overview on H.pylori effect on gastric tissue via bioinformatics analysis of microarray-identified miRNAs and its target genes.

BACKGROUND

MicroRNAs which control about 30 to 60% of gene expression in human body play a critical role in different cell growth stages. Expression modification of non-coding (NC) RNAs in H.pylori infections requires further investigations to provide better understanding of their roles in the body.

METHODS

GSE54397, the microRNA microarray dataset, was analyzed by GEO2R, the online GEO database for detection of differentially expressed microRNAs and lastly the potential target genes as well as their associated pathways.

RESULTS

A total of 244 miRNAs were detected as differentially expressed (p<0.05 and FC>2) in non-cancerous tissue of gastric with H.pylori infection in comparison with tissues without H.pylori infection. The findings indicated that hub microRNAs and target genes of up-regulated network are KIF9, DCTN3, and CA5BP1 along with hsa-miR-519d, hsa-miR-573, hsa-miR-646, hsa-miR-92a-1, hsa-miR-186, and hsa-miR-892a, respectively. For the down-regulated network, genes of RABGAP1, HSPB11 and microRNAs of hsa-miR-620, hsa-miR-19b-2, hsa-miR-555, and hsa-let-7f-2 were hubs. Most of the up-regulated microRNAs are involved in gastric cancer development while there is no evidence for the down-regulated ones. Yet, all of the hub down-regulated miRNAs are reported to have associations with different kinds of cancer.

CONCLUSION

The introduced hub miRNAs and genes may serve as feasible markers in the mechanisms of H.pylori infection for different kinds of gastric diseases, in particular gastric cancer. However, their role requires further investigations.

Prevalence of Helicobacter pylori infection in Sari Northern Iran; a population based study

AIM

In this study prevalence rate of Helicobacter pylori and its associated factors have been investigated in urban and rural areas of Sari.

BACKGROUND

Helicobacter pylori has an important role in gastrointestinal diseases including peptic ulcer and gastric cancer. It is the most common infection in human population worldwide. Hence, the epidemiology of this infection in all parts of the world is of utmost importance.

METHODS

We conducted a cross-sectional study on 497 individuals ranging 15-65 years of age in Sari city and its surrounding rural residents. The sampling method was a cluster random sampling multi staged in stratified population by urban and rural areas. Questionnaires for personal and socio-economic data were filled. Blood samples were drawn and kept for analysis (IgG antibody ELISA for Helicobacter pylori). The data was analyzed by SPSS statistical software and Chi-square test and logistic regression were used.

RESULTS

The prevalence of helicobacter infection was 44.5% in the studied population. This prevalence was 41.3% and 47.8% in urban and rural areas, respectively. Just a significant association between the infection and the age of subjects was observed in multiple regression analysis (p=0.001). However, in univariate analysis the level of education was also significantly associated with Helicobacter pylori infection (p=0.015). No other variable was associated with the infection.

CONCLUSION

The prevalence of helicobacter infection has dropped significantly in the region in comparison with the previous studies during the last 15 years.

Effect of sub-MIC values of metronidazole, ciprofloxacin, and imipenem on the growth and toxin production in Clostridioides difficile

AIM

This study intends to investigate the effect of sub-minimum inhibitory concentration (sub-MIC) of metronidazole, ciprofloxacin, and imipenem on the growth and toxin production in Clostridioides difficile.

BACKGROUND

C. difficile is the most common causative agent of hospital-acquired diarrhea. Toxin production in C. difficile appears to be a critical process for induction of the disease. Several factors such as antibiotics can facilitate growth and toxin production in C. difficile.

METHODS

Five C. difficile strains were grown with and without sub-MIC concentrations of metronidazole, ciprofloxacin, and imipenem (0.5x MIC). The bacterial growth was measured by density at OD620 nm in 0, 4, 8, 12 and 24 h post inoculation. Toxin production was detected using ELISA in culture supernatants as well as in cell pellet.

RESULTS

The five strains showed minor growth variations in the presence and absence of antibiotic sub-MIC values, except for metronidazole, in which the sub-MIC concentration reduced the growth rate of the resistant isolate in comparison with the control without antibiotic. There were no significant variations in the levels of toxin production with the sub-MIC values of antibiotics examined in comparison with antibiotic-free controls. However, the amount of toxin production in the culture supernatant was greater than in the cell pellet.

CONCLUSION

The findings of this study suggested that sub-MIC concentrations of antibiotics may have minor effects on bacterial growth and toxin production of C. difficile. Taken together, these findings suggest that presence of antimicrobial agents increased expression levels of certain genes, particularly virulence genes, which may help C. difficile to survive.

Expression levels of A disintegrin and metalloproteases (ADAMs), and Th17-related cytokines and their association with Helicobacter pylori infection in patients with gastroduodenal diseases

Expression levels of A disintegrin and metalloproteases (ADAMs) (10 and 17) and Th17-related cytokines [interleukin (IL) 17A, IL-17F, IL-33, IL-23, IL-23R] were investigated by quantitative real time polymerase chain reaction in gastric biopsies of patients with different gastroduodenal pathologies in the presence and absence of Helicobacter pylori infection. Patients with gastric cancer (GC) (n = 70, intestinal-type 38 and diffuse type 32), peptic ulcer disease [n = 50, duodenal ulcer (DU) 16 and gastric ulcer (GU) 34] and functional dyspepsia (n = 120) were included in the study. Further, the expression levels of ADAMs and Th17 cytokines were correlated with H. pylori cytotoxin-associated genes pathogenicity island (cagPAI) status. Expression levels of ADAMs (10 and 17) and Th17-related cytokines (IL-17A, IL-23, IL-23R) were significantly higher in H. pylori-positive than in H. pylori-negative gastric biopsies. Significant increase in ADAM17 and Th17 cytokines (IL-17A and IL-23) expressions was observed in patients with GU and intestinal-type GC in the presence of H. pylori infection and in strains harbouring intact cagPAI. Expression levels of IL-17A, IL-23 and ADAM17 were strongly correlated with GU and intestinal-type GC and weakly with DU and diffuse-type GC in the presence of H. pylori infection. Higher expression levels of ADAM17 and Th17 cytokines (IL-17A and IL-23), and their strong correlation with GU and intestinal-type GC patients in the presence of H. pylori and its intact cagPAI status, suggest a possible role of strain specificity in the pathogenesis of these diseases.

Risk of gastric cancer in association with Helicobacter pylori different virulence factors: A systematic review and meta-analysis

INTRODUCTION

It has been proposed that specific analysis of Helicobacter pylori virulence factors can be suitable for predicting of post H. pylori infection disorders like gastric cancer (GC). The present study was designed to evaluate the association between different virulence factors of H. pylori and GC.

METHODS

Studies investigated the association between virulence factors of H. pylori and GC were collected from the several databases. All analysis was performed by Comprehensive Meta-Analysis V2.2 software (Biostat, Englewood, NJ, USA).

RESULTS

Based on a comprehensive literature search, 25 eligible studies were included for meta-analyses. Infection with cagA- and vacA s1m1-positive H. pylori strains were significantly associated with increased risk of GC (OR of [2.82 (95% CI 1.96-4.06), P < 0.001]) and ([1.75 (95% CI 1.04-2.96), P 0.034)], respectively.

CONCLUSIONS

Infection by H. pylori strains with positive vacA s1m1 and the cagA genes can significantly increase the risk of GC. The association between the vacA s1m1 and the cagA and GC, suggests that screening of these genes may be helpful for identifying populations at higher risk for GC.

Evaluating the relationship between serum immunoglobulin G (IgG) and A (IgA) anti-CagA antibody and the cagA gene in patients with dyspepsia

BACKGROUND AND OBJECTIVES

The cytotoxin-associated gene (cag) pathogenicity island is reported to be a major virulence factor of Helicobacter pylori infection. It is previously reported that the cagA-positive strains are more virulent, so it can be postulated that the cagA-positive gastritis will be more severe and the serum immunoglobulin G (IgG) and A(IgA) anti-CagA antibody titer will be higher. The aim of this study was to compare the relationship between IgG and IgA anti-CagA antibody and the cagA gene expression in patients with dyspepsia. Serum samples obtained from 130 dyspeptic patients with positive H. pylori in histological and Geimsa staining were tested for serum IgG and IgA anti-CagA antibody using the enzyme-linked immunosorbent Assay. The expression of the cagA gene was determined using PCR on the biopsy samples, taken via endoscopy.

RESULTS

In our material, the sensitivity of IgG anti-CagA antibody in identifying patients with a proven infection with the cagA-positive strains was 97.67%, and the negative likelihood ratios was 0.06. There was not significant correlation between serum IgA anti-CagA and the expression of the cagA gene among the dyspeptic patients.

CONCLUSION

The IgG antibody titer was significantly higher in our patients with the cagA-positive H. pylori strain. However, in daily practice, the level of the IgG antibody titer cannot predict whether or not an individual carries a cagA-positive H. pylori strain, because there is a major overlap in the IgG antibody titer between the cagA-positive and cagA-negative patients.

Pancreatic adenocarcinoma protein-protein interaction network analysis

AIM

Gene assessment of pancreatic adenocarcinoma disease via protein-protein interaction (PPI) Network Analysis.

BACKGROUND

Diagnosis, especially early detection of pancreatic adenocarcinoma as a lethal disease implies more investigation. PPI Network Analysis is a suitable tool to discover new aspects of molecular mechanism of diseases.

METHODS

In the present study the related genes to pancreatic adenocarcinoma are studied in the interactome unit and the key genes are highlighted. The significant clusters were introduced by Cluster-ONE application of Cytoscape software 3.4.0. The genes are retrieved from STRING date base and analyzed by Cytoscape software. The crucial genes based on analysis of central parameters were determined and enriched by ClueGO v2.3.5 via gene ontology.

RESULTS

The number of 24 key genes among 794 initial genes were highlighted as crucial nodes in relationship with pancreatic adenocarcinoma. All of the key genes were organized in a cluster including 216 nodes. The main related pathways and cancer diseases were determined.

CONCLUSION

It was concluded that the introduced 24 genes are possible biomarker panel of pancreatic adenocarcinoma.

Study of prevalence, distribution and clinical significance of Blastocystis isolated from two medical centers in Iran

AIM

This study aimed to survey prevalence and clinical significance of Blastocystis among symptomatic and asymptomatic groups.

BACKGROUND

Blastocystis is a prevalent microorganism that is found in intestine of human and majority of animals. However, most studies have failed to establish correlation between the presence of the parasite and clinical manifestations.

METHODS

from Dec 2016 to Jun 2017, 554 stool samples were collected from symptomatic and asymptomatic subjects referred to Imam Hossein Hospital and Gastroenterology and Liver Diseases Research Institute, Tehran, Iran. All samples were concentrated using conventional formalin-ethyl acetate concentration and then were microscopically examined using Lugol's iodine staining and light microscope. The fresh stool samples were also cultivated in DMEM medium and were examined for growth of Blastocystis every 48 hours with direct smear slides for 10 days.

RESULTS

Blastocystis was observed among 93 (16.8%) of stool samples cultivated in DMEM. The findings represented that 64/398 (16.08%) and 29/156 (18.58%) of asymptomatic and symptomatic patients were infected with Blastocystis, respectively. In addition, there was no significant correlation between presence of symptoms and carrying Blastocystis (P=0.528), although statistically significant association was observed between presence of urticaria and carrying Blastocystis (P<0.05). Furthermore, a statistically significant correlation between observing the parasite and different age groups was seen (P<0.05).

CONCLUSION

Blastocystis is a prevalent parasitic eukaryote among symptomatic and asymptomatic populations despite the higher prevalence among symptomatic group that suggests the chance of infection with Blastocystis raises with age.

Protein profiling of infected human gastric epithelial cells with an Iranian Helicobacter pylori clinical isolate

AIM

The main objective of this study was to use high throughput approach to characterize the response of human gastric epithelial cells to Helicobacter pylori (H. pylori) infection at protein level.

BACKGROUND

Alteration of host cell protein profiles occurs due to H.pylori infection. This alteration seems to be strain specific. High throughput approaches, such as proteomics, can describe changes that occurs at the protein levelin the infected cells in response to H.pylori infection. In accordance with this point of view, we used two dimensional electrophoresis (2-DE)/MS to determine changes in proteome profile of gastric epithelial cells infected with a clinical isolate of H. pylori from an Iranian patient.

METHODS

Human gastric epithelial cells (AGS) were infected by an Iranian H.pylori isolate (complete cagPAI, vacA s2m2, babA2, iceA1, sabA). The altered protein patterns separated by 2-DE were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis.

RESULTS

The results showed 40 spots with significantly different intensities between the 2-DE gels. Protein SETSIP and Endoplasmic reticulum resident protein 29 were identified by MALD-TOF and Mascot search. Proteomic analysis for functional roles of these proteins showed that mechanisms to deal with stress conditions and transcriptional activator related to cell reprogramming are involved in H. pylori infection.

CONCLUSION

Using high throughput approaches, such as proteomics, we can provide further molecular details about interaction of H. pylori strains with the infected cells at protein level.

ATP binding cassette and cholecystokinin A receptor genetic variations in gallstone susceptibility

AIM

It was aimed to assess the association of four polymorphisms and relative haplotypes in the ATP binding cassettes and cholecystokinin A receptor (rs6720173, rs11887534, rs4148217, rs1800857) with the risk of gallstone.

BACKGROUND

Gallstone is a multifactorial disease. Besides high penetrance genes, low or moderate penetrance polymorphisms may increase susceptibility to gallstone.

METHODS

200 gallstone patients and 251 healthy controls were analyzed in a case-control association model. Genotyping was carried out by restriction fragment length polymorphism. Randomly 10% of samples underwent for direct sequencing to confirm results.

RESULTS

Heterozygote variant of rs11887534 demonstrated protective effect on the risk of gallstone susceptibility in males (P=0.013; OR=0.125; CI95%=0.048-0.325). In contrast, C/C genotype associated with gallstone susceptibility in females (P=0.004; OR=5.555 CI95%=1.975-10.632). Moreover, rs1800857 showed association only in females (P=0.019; OR=0.283; CI95%=0.099-0.811). Haplotype analysis for rs1800857 showed GC, CC and CA association with gallstone.

CONCLUSION

The most imperative polymorphisms of contributing genes to gallstone were analyzed in this study and rs11887534 and rs1800857 appeared to be associated with gallstone, which is expected to be further verified in a larger cohort in the future.

Management of multi-drug resistant Helicobacter pylori infection by supplementary, complementary and alternative medicine; a review

Helicobacter pylori is recognized as the most common bacterial pathogens colonizing the gastric epithelium of nearly half of the world's population. This bacterium is the main etiological cause of gastroduodenal ulcers, and more importantly as the substantial risk factor for development of gastric cancer. The emergence and rapid increase in the prevalence of multi-drug resistant phenotypes have posed major pitfalls in effectiveness of various treatment regimens and eradication strategies against H. pylori infections. Several natural products and supplementary food components have been reported to have established anti-H. pylori activity. Herein, we review the application and efficacy of some specific natural products and foodstuffs such as milk, bee products (honey and propolis), fish oil, vitamins C and E, and also a nickel free-diet used as anti-H. pylori alternative treatment regimens.

The evaluation of functional results before and after laparoscopic Heller myotomy for achalasia: a single center experience

AIM

The aim of this study was to evaluate and compare the functional results before and after laparoscopic Heller myotomy for Iranian patients with achalasia.

BACKGROUND

Achalasia is a severe neuromuscular disorder of the esophagus, characterized by the loss of peristalsis and an inability of the lower esophageal sphincter (LES) to reach optimal relaxation.

METHODS

In this cross sectional study, patients who underwent Heller myotomy for achalasia via laparoscopy in Taleghani Hospital Tehran, Iran were evaluated. Symptoms including pressure of residual, integrated relaxation sphincter (IRP), pressure of free drinking, pressure of LES, dysphasia score and peristalsis movement was measured and recorded by manometry before and after (2 months) treating with Heller myotomy.

RESULTS

In this study, 23 patients with achalasia (12 females and 11 males) with a mean age of 30±3.5 years (minimum 20, maximum 44 years) who met the inclusion criteria of the study were examined. Results of this study showed that, all the diagnostic criteria that were measured before the treatment was significantly different from after the treatment (P<0.05). The average decline in LES, IRP, Residual Pressure, Free drinking esophagus, and dysphasia score were 23.1 mmHg, 16.24 mmHg, 18,7 mmHg, 18.9 mmHg, and 5.0 unit, respectively. Also the average increase of the peristalsis movement was 8.26±13.7 in 8 patients.

CONCLUSION

Considering the results of Heller myotomy surgery can be as a treatment of choice for achalasia. Free Drinking pressure can be a suitable criteria after treatment for evaluation and prediction of the reducing the dysphasia score after the surgery.

Eosinophilic gastroenteritis; a report of two cases with different presentations

Eosinophilic gastroenteritis is a rare inflammatory disease, defined by infiltration of eosinophils in gastrointestinal (GI) tract, but the etiology of this disorder is unknown. Depends on the involvement region of Eosinophilic gastroenteritis, GI symptoms are variable including abdominal pain, malabsorption, gastric and duodenal ulcer. Due to its non-specific symptoms, the diagnosis is based on upper GI endoscopy followed by histopathological examination of the biopsies, which shows eosinophilic infiltration in different layers of GI tract. In this article we report two cases with gastrointestinal disorders. The first case was a 52-year-old man with a history of peripheral edema over the past 3 months and low level of serum albumin. All the necessary evaluations were done and increase number of eosinophils were found in duodenal biopsies. The second case was a 42-year-old man presented with a history of chronic diarrhea over the past two years. Main causes of diarrhea were ruled out and small intestine biopsies confirmed submucosal eosinophilic infiltration. Therefore, corticosteroid therapy was administered for both patients then they were followed for a year. During this time all of the symptoms were disappeared and they did not recur in the first year of follow up.

Occurrence of Helicobacter pylori and its major virulence genotypes in dental plaque samples of patients with chronic periodontitis in Iran

AIM

This study was aimed to investigate the presence of H. pylori and its virulence genotypes in dental plaques of Iranian patients with chronic periodontitis.

BACKGROUND

Helicobacter pylori is a Gram-negative bacterium that is associated with atrophic gastritis, peptic ulcer, and gastric cancer. Several studies have detected this bacterium in the oral cavity, suggesting it as a potential reservoir.

METHODS

A hundred individuals were divided in 2 groups: 50 patients with chronic periodontitis (case group), and 50 subjects in non-periodontitis (control group). Supragingival and subgingival plaque samples were collected from the individuals using wood wedges and sterile paper points respectively, and prepared for PCR analysis.

RESULTS

Totally, H. pylori DNA was detected in 5 out of 100 (5%) dental plaques. Of 5 dental plaques positive for H. pylori, cagA gene was detected in 4 specimen, 3 in periodontitis group and one in non-periodontitis group. The H. pylori vacA s1m1 genotype was predominantly detected in 2/5 samples. The babA2 gene was detected in all (5/5) H. pylori-positive dental plaques. There was no significant correlation between the presence of H. pylori genotypes from dental plaques and chronic periodontitis (P > 0.05).

CONCLUSION

Our results revealed that the rate of H. pylori is very low in the dental plaques of Iranian patients with chronic periodontitis. Majority of H. pylori strains from oral cavity were highly virulent based on the main clinically virulence factors they carried.

Screening of precancerous gastric lesions by serum pepsinogen, gastrin-17, anti-helicobacter pylori and anti- CagA antibodies in dyspeptic patients over 50 years old in Guilan Province, north of Iran

BACKGROUND

The aim of this study was to investigate the value of serum gastric markers to differentiate between patients with precancerous lesions and nonatrophic chronic gastritis.

MATERIALS AND METHODS

Serum samples of 128 patients with dyspepsia who were candidates for endoscopic examination were tested for pepsinogen (PG I and PG II), PG I/II ratio, gastrin 17(G-17), anti-Helicobacter pylori (anti-H pylori ) and anti- CagA antibodies. Two sample t-tests, chi-square tests and Pearson's correlation analyses were used for analysis using SPSS (version 20).

RESULTS

PGI, PG I/II ratio values were decreased significantly in the precancerous lesion group (0.05, 0.001 respectively). The frequency of H pylori infection was significantly (p=0.03) different between the two groups ofthe study.

CONCLUSIONS

We suggest PGI and the PG I/II ratio as valuable markers for screening of premalignant gastric lesions.

Helicobacter pylori and gastric cancer: a state of the art review

Gastric cancer is the third most common cause of cancer-related death in the world. It is now well- established that Helicobacter pylori infection predispose individuals toward gastric adenocarcinoma later in life. It has since been classified as a class I carcinogen by the World Health Organization. Research suggests that the oncogenic effects of Helicobacter pylori can occur through a variety of mechanisms, including the indirect inflammatory effects of Helicobacter pylori on the gastric mucosa and the direct epigenetic effects of Helicobacter pylori on individual cells. Whilst infected with Helicobacter pylori, a combination of environmental and host-dependent factors determines the likelihood of developing gastric cancer. Controversy remains regarding the effects of eradication of Helicobacter pylori on the prevention of further progression of gastric lesions and the possibility for regression of atrophic gastritis. The aim of this review is to synthesis different elements that contribute to the step-wise progression of normal gastric mucosa to gastric adenocarcinoma. This review helps clinicians to better identify those infected individuals who are at high risk of developing gastric cancer and implement the necessary investigations and treatment.

CagA and VacA genotypes in peptic ulcer disease and non-ulcer dyspepsia: a case-control study

BACKGROUND

The cag pathogenicity island includes a number of genes, including cytotoxin-associated protein A (cagA) and vacuolating cytotoxin (vacA) genotypes, which are associated with bacterial virulence. Although the role of cagA and vacA in the virulence of Helicobacter pylori (H. pylori) is well-established in epidemiological studies, the relationship between the cagA and vacA genotypes in Iran has yet to be fully elucidated. This study compared the association between cagA and vacA genotypes between peptic ulcer disease (PUD) patients and non-ulcer dyspeptic (NUD) patients.

METHODS

This case control study was done on 130 patients with positive H. pylori in histological and Giemsa reports. The case group comprised 65 PUD patients, and the control group included 65 NUD patients. The presence of the cagA and vacA genotypes was determined using polymerase chain reaction (PCR) on biopsy samples, taken via endoscopy.

RESULTS

Both cagA and vacA genotypes were positive in 51.5% (17) of the PUD group and 20% (6) of the NUD group (p= 0.009), and both cagA and vacA genotypes were negative in 48.5% (16) and 80% (24) of the case and control groups, respectively (p= 0.03). CagA-positive H. pylori was detected in 41.5% (27) and 24.6% (16) of the case and control groups, respectively (p= 0.001), and vacA-positive H. pylori was found in 60% (39) and 46% (30) of the case and control groups, respectively.

CONCLUSION

Both cagA and vacA genotypes were more prevalent in the PUD patients than in their NUD counterparts among our Iranian samples. It is seems that the determination of these two genotypes in PUD patients is a good screening tool for patient selection for endoscopy and treatment.

Clinical relevance of cagL gene and virulence genotypes with disease outcomes in a Helicobacter pylori infected population from Iran

Helicobacter pylori infection is common in Iran as in other developing countries. Certain genotypes of H. pylori have been associated with increased occurrence of chronic gastritis, peptic ulcers, and gastric adenocarcinoma. The aim of this study was to investigate the clinical relevance of cagL gene and other virulence genotypes of H. pylori isolates with clinical outcomes in Iranian patients. Totally, 126 symptomatic patients who underwent gastroduodenal endoscopy were enrolled in the study. Sixty-one H. pylori strains were isolated from the patients studied. The presence of the cagL, cagA, vacA, iceA, babA2 and sabA genes in the corresponding H. pylori isolates were determined by polymerase chain reaction and the results were compared with clinical outcomes and histopathology. The cagL, cagA, vacA s1, vacA s2, vacA m1, vacA m2, iceA1, iceA2, babA 2 , and sabA genotypes were detected in 96.7, 85.2, 75.4, 24.6, 29.5, 70.5, 42.6, 23, 96.7, and 83.6% of the isolates, respectively. The three genotypic combinations, cagL/cagA/vacAs1m1/iceA1/babA2/sabA, cagL/cagA/vacAs1m2/iceA1/babA2/sabA, and cagL/cagA/vacAs1m2/iceA2/babA2/sabA were determined as the most prevalent combined genotypes. There was a significant correlation between the presence of cagL gene and cagA positivity (P = 0.02). No significant correlation was found between the various genotypes and clinical outcomes (P > 0.05). The present study showed a very high prevalence of cagL genotype among the H. pylori isolates from Iranian patients. Our results demonstrated that neither single genotype nor combination genotypes of virulence-associated genes was significantly helpful markers for predicting the severity of gastroduodenal disease associated with H. pylori infection in Iranian patients.

Investigation of the association between clinical outcome and the cag pathogenicity-island and other virulence genes of Helicobacter pylori isolates from patients with dyspepsia in Eastern Turkey

The aims of our work were to determine the presence of the cag pathogenicity-island (cag PAI) and other virulence genes of Helicobacter pylori recovered from patients with gastritis and peptic ulcer, and to investigate the correlation of these virulence genes with clinical outcome. The presence of the cagA, the promoter regions of cagA, cagE, cagT, and the left end of cag-PAI (LEC), cag right junction (cagRJ), the plasticity region open reading frames (ORFs), vacA and oipA genes among 69 H. pylori isolates were determined by polymerase chain reaction. Intact cag PAI was detected in only one (1.4%) isolate. The cagA gene was identified in 52.1% and 76.2% of isolates from patients with dyspepsia (gastritis and peptic ulcer), respectively. The plasticity region ORFs i.e. JHP912 and JHP931 were predominantly detected in isolates from peptic ulcer. Less than 25% of the isolates carried other ORFs. Types I, II and III were the most commonly found among the isolates. None of the isolates possessed type Ib, 1c, IIIb, IV and V motifs. The most commonly vacA genotypes were s1am1a and s1m2 in isolates with peptic ulcer and gastritis, respectively. The results confirmed that the prevalence of oipA (Hp0638) gene was 75% and 85.7% in patients with gastritis and peptic ulcer, respectively. Furthermore, vacA s1am1a positivity was significantly related to peptic ulcer (p < 0.05).

Evaluation of the effect of cagPAI genes of Helicobacter pylori on AGS epithelial cell morphology and IL-8 secretion

Helicobacter pylori cagPAI genes play an important role in pathogenesis, however little is known about their functions in isolates from Turkish patients. We aimed to evaluate the intactness and the effect of the cagPAI genes (cagT, cagM, cagE, cagA) and cagA EPIYA motifs on the AGS morphological changes and IL-8 induction. Of 53 patients 38 were found infected with H. pylori. PCR amplification of the cagPAI genes showed 42.1 % intact, 39.5 % partially deleted and 18.4 % with complete deletions. Isolates from gastritis, duodenal and gastric ulcer patients with intact and partially deleted cagPAI genes induced higher IL-8 secretion than those with complete deletions. Isolates from gastritis patients had higher deletion frequencies of the cagT and cagM genes than the other two genes. Infection of AGS cells with isolates that possess intact cagPAI and EPIYA-ABC resulted in the formation of the hummingbird phenotype. The cagA positive isolates induced higher IL-8 secretion than cagA negative isolates. Isolates from DU patients with more than one EPIYA-C motif induced higher concentrations of IL-8 than those with EPIYA-ABC. In conclusion, the intactness of the cagPAI in our isolates from different patients was not conserved. An intact cagPAI was found to play an important role in the pathogenesis of DU but not GU or gastritis. The cagA gene, but not other cagPAI genes, was associated with the induction of IL-8 and the morphological changes of the AGS cells. An increase in the number of EPIYA-C motifs had noticeable effect on the formation of the hummingbird phenotype.

Searching the H. pylori; serology & PCR in children with adenoid hypertrophy and rhino sinusitis: a cross sectional study, Tehran, Iran

OBJECTIVE

Searching the H. pylori -DNAs in adenoid and IgA, IgG antibodies in serum of children.

METHODS

A cross- sectional study had done upon 53 children (Mean age 8 ±1.9 years) with adenoid surgery in ENT and Pediatric Department of Rasul Akram Hospital (2008-2010). Of 53 cases with adenoid surgery, 40 cases had rhino sinusitis (in sinus CT scan). The resected adenoid tissues (n=40) centrifuged and homogenized and its DNAs extracted and searched for H. pylori- DNAs by qualitative PCR. Serum H. pylori antibodies (IgG &IgA ELISA) calculated quantitatively. Chi square values (p < 0.05) calculated for all categorical variables. The agreement between serologic test and PCR was assessed by the calculation of kappa statistic.

RESULTS

Positive PCR for H. pylori detected in 15%of cases; regardless of sex and age of cases. Positive IgA: 17.5% (7/40) and IgG: 20% (8/40) respectively. All cases with positive H. pylori- IgG were female; p=0.003 and meaningful differences in mean age of cases observed for positive IgA (p=0.001) and IgG (p=0.01). Poor agreement observed between positive PCR and serum IgG&IgA (Fisher's Exact test=0.3; 0.5).

CONCLUSION

Positive PCR in adenoid tissue (15%) was very close to positive serum IgA (15%) but without any agreement for each case. The H. pylori infection may have a relative role at least in 15% of children with adenoid surgery. Chronic sinusitis and ear infection might be added to infected adenoid tissue as a reservoir for bacteria. The search by specific culture may elucidate better the role of H. pylori infections in both gastric and adenoid tissues. The decision for use of antibiotics to eradicate the H. pylori infection in recurrent or chronic adenotonsillar infections (with rhinosinusitis) before adenoid surgery needs Randomized Control Trial (RCT) studies. Drug of choice for eradication of H. pylori dependent to antibiotic sensitivity test in each country.

In silico experiment with an-antigen-toll like receptor-5 agonist fusion construct for immunogenic application to Helicobacter pylori

BACKGROUNDS

Helicobacter pylori colonize the gastric mucosa of half of the world's population. Although it is classified as a definitive type I carcinogen by World Health Organization, there is no effective vaccine against this bacterium. H. pylori evade the host immune response by avoiding toll-like detection, such as detection via toll-like receptor-5 (TLR-5). Thus, a chimeric construct consisting of selected epitopes from virulence factors that is incorporated into a TLR-5 ligand (Pseudomonas flagellin) could result in more potent innate and adaptive immune responses.

MATERIALS AND METHODS

Based on the histocompatibility antigens of BALB/c mice, in silico techniques were used to select several fragments from H. pylori virulence factors with a high density of B- and T-cell epitopes.

RESULTS

These segments consist of cytotoxin-associated geneA (residue 162-283), neutrophil activating protein (residue 30-135) and outer inflammatory protein A (residue 155-268). The secondary and tertiary structure of the chimeric constructs and other bioinformatics analyses such as stability, solubility, and antigenicity were performed. The chimeric construct containing antigenic segments of H. pylori proteins was fused with the D3 domain of Pseudomonas flagellin. This recombinant chimeric gene was optimized for expression in Escherichia coli. The in silico results showed that the conserved C- and N-terminal domains of flagellin and the antigenicity of selected fragments were retained.

DISCUSSION

In silico analysis showed that Pseudomonas flagellin is a suitable platform for incorporation of an antigenic construct from H. pylori. This strategy may be an effective tool for the control of H. pylori and other persistent infections.

Helicobacter pylori in Iran: A systematic review on the association of genotypes and gastroduodenal diseases

BACKGROUND

Helicobacter pylori (H. pylori) infection is known as a major etiologic factor for a variety of gastroduodenal diseases. In Iran, with a high rate of H. pylori infection close to 90%, numerous studies have revealed many aspects of interaction between the bacterium, mucosal surface and induction of disease outcome. The organism is genetically diverse and several virulence factors are attributed to the more virulent strains. The well-characterized virulence factors of H. pylori are cytotoxin associated gene A and vacuolating cytotoxin gene A. The distribution pattern of H. pylori genotypes and its association with disease status varies geographically. The present review focused on the virulence factors and genotyping of H. pylori in relation to gastroduodenal disorders in different regions of Iran.

METHODS

In total, 398 studies were reported on different aspects related to H. pylori in our electronic search from 1995-2011. H. pylori infection and its virulence factors in association with disease status were investigated in 159 reports. Looking specifically at the gastrointestinal tract disorders, the most relevant reports including 37 papers were selected.

RESULTS

We found no correlation of cagA genotype and disease status in the majority of studies, whereas vacA was demonstrated as a useful marker in predicting the disease outcome. The results of reports on other virulence factors of H. pylori such as blood group antigen-binding adhesion gene A, the induced by contact with epithelium gene A, the outer inflammatory protein A, the duodenal ulcer promoting gene A, and Helicobacter outer membrane gene and their relation with disease status were contradictory.

CONCLUSIONS

Although different markers of H. pylori were emphasized as useful when predicting disease outcomes in some studies, the inconsistent researches and the scarcity of data made any conclusion or even comparison impossible. Considering the gap of information observed during our search relating to genotyping and other aspects of H. pylori infection, further investigations are suggested.

Helicobacter pylori homB, but not cagA, is associated with gastric cancer in Iran

While several distinct virulence factors of Helicobacter pylori have been shown to be associated with different clinical outcomes, there is still much to learn about the role of different bacterial factors in gastric carcinogenesis. This study looked at the distribution of the cagA, homA, and homB genes in strains isolated from patients suffering from gastroduodenal diseases in Iran and assessed if there was any association between disease state and the presence of the aforementioned virulence factors. Genomic DNA from 138 H. pylori strains was isolated and genotyped via PCR. Strains were obtained from dyspeptic patients (35 from gastritis patients, 62 from peptic ulcer patients, and 41 from gastric cancer patients) at the Teaching Touba Clinic and Imam Hospital of the Mazandaran University of Medical Sciences in Sari, Iran. The overall prevalence rates of cagA, homA, and homB were 58%, 54%, and 43%, respectively. Stratification of patients showed a significant difference in the prevalence of H. pylori virulence genes across the disease states. The frequency of homB was statistically significantly higher in gastric cancer patients (78%) than in patients suffering from peptic ulcers (20%) or gastritis (43%) (P < 0.0001). The presence of homB was also associated with the presence of cagA (r = 0.243). These data suggest that in this population the presence of homB may be a predictor of more virulent strains of H. pylori and influence the severity of disease manifestation.

Benefits of Helicobacter pylori cagE genotyping in addition to cagA genotyping: a Bulgarian study

Associations of Helicobacter pylori cagE status with complex patient characteristics remain to be elucidated in Eastern Europe. The aim of this study was to assess the frequencies of cagE gene and cagA/cagE combinations in H. pylori strains from symptomatic Bulgarian patients and to improve cagA detection. cagA and cagE genotypes were evaluated in 219 patients with single-strain infections. In total, 84.9% of strains were cagA (+), while 68.5% were cagE (+). cagA (+), cagE (+), and cagA (+)/cagE (+) strains were more prevalent in peptic ulcer (93.8%, 84.4%, and 84.4%) compared with nonulcer patients (81.3%, 61.9%, and 61.3%, respectively). In elderly patients, cagE (+) and cagA (+)/cagE (+) strains were 1.9-fold more common than in the 12 children evaluated. Only 10% of the elderly subjects harbored low-virulence cagA (+)/cagE (-) strains compared with 16.8% of adults and 41.7% of children. Intriguingly, prevalence of the cagA (+)/cagE (-) genotype was 2.1-fold lower in men than in women, suggesting a higher frequency of more virulent strains in men. The presence of both cag genes and combinations was not linked to strain susceptibility to clarithromycin or metronidazole, place of residence, or prior therapy. Use of an extra primer pair increased cagA detection in 14.7% of 31 cagA (-) strains. In conclusion, use of a second primer pair for the cagA gene can be recommended in countries with common cagA (+) strains. Although both cag genes were linked to severe diseases in Bulgarian patients, the best discrimination of virulent strains was obtained by the cagA/cagE combination or by the cagE gene alone. cagE prevalence increased gradually with patient age, while the cagA (+)/cagE (-) genotype, implying a disrupted cag pathogenicity island, was associated with both younger age and female gender.

Infection with specific Helicobacter pylori-cag pathogenicity island strains is associated with interleukin-1B gene polymorphisms in Venezuelan chronic gastritis patients

BACKGROUND

The cag pathogenicity island (cag-PAI) is one of the major virulence factors of Helicobacter pylori, showing considerable geographic variation.

AIM

We investigated the prevalence of cagA, cagE, and cagT genes of cag-PAI and their association with proinflammatory IL-1B-511/-31/+3954 polymorphisms in Venezuelan chronic gastritis patients from a high-risk gastric cancer region.

METHODS

Presence of cag-PAI genes and IL-1B polymorphisms in 121 biopsy specimens was evaluated by polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (RFLP), respectively.

RESULTS

cagA (+) and triple-positive (cagAET (+)) strains were detected in 79.3% and 70.2% of patients, respectively. We found that infection with cagA (+) and cagAET (+) strains was associated (P < 0.05) with hosts harboring both IL-1B +3954C allele and IL-1B-511T/-31C/+3954C haplotype (TCC (+)). The frequency of gastric atrophy was significantly higher (P < 0.020) among cagAET (+)/IL-1B-TCC (+) combined genotype carriers.

CONCLUSION

Carriage of IL-1B +3954C allele and IL-1B-TCC (+) haplotype could favor colonization of bacterial cagAET (+) strains, and the combination of these bacterial and host haplotypes could play a synergistic role in development of premalignant gastric lesions. This work contributes to understanding of the complex interaction between H. pylori virulence factors and cytokine genotypes involved in gastrointestinal diseases.

Facing resistance of H.pylori infection

Helicobacter pylori is an important human pathogen and a gram-negative, spiral shaped and microaerophilic bacteria with persistence colonization in gastric mucosa, causes gastroduodenal inflammation and destruction, resulting in diseases such as duodenal ulcer disease, gastric ulcer disease. When H.pylori discovered by Warren and Marshall, effective therapy developed for this infection and resulted in remarkable change in management of PUD and dyspepsia. Nowadays, the increasing prevalence of drug resistance has complicated successful therapy, considering more attention for appropriate therapy. Ideally, therapy should be based on pretreatment drug susceptibility testing, and empiric use of eradication therapies should assume the presence of antimicrobial drug resistance and use increased doses for 14 days.

Analysis of 3'-end variable region of the cagA gene in Helicobacter pylori isolated from Iranian population

BACKGROUND AND AIMS

The 3' region of the cagA gene, the most well-known virulence factor of Helicobacter pylori, contains Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs. Four segments flanking the EPIYA motifs, EPIYA-A, -B, -C, or -D, were reported to play important roles in H. pylori-related gastroduodenal pathogenesis. The aim was to determine the roles of EPIYA segments in gastroduodenal pathogenesis in an Iranian population.

METHODS

A total of 92 cagA-positive Iranian strains isolated from dyspepsia patients with non-ulcer dyspepsia (n = 77), peptic ulcer (n = 11) and gastric cancer (n = 4) were studied. The EPIYA motif genotyping was determined by polymerase chain reaction and sequencing.

RESULTS

A total of 86 (93.5%) strains had three copies of EPIYA (ABC type), three (3.3%) had four copies (ABCC type) and three (3.3%) had two copies (AB type). The alignment of the deduced protein sequences confirmed that there were no East Asian type EPIYA-D sequences (EPIYATIDFDEANQAG) in Iranian strains. When the prevalence of strains with multiple EPIYA-C segments in Iran was compared with previously published data, it was much lower than that in Colombia and Italy, but was higher than that of Iraq, and the patterns were parallel to the incidence of gastric cancer in these countries.

CONCLUSION

The structure of the 3' region of the cagA gene in Iranian strains was Western type. Although we could not find differences between EPIYA types and clinical outcomes, low prevalence of strains with multiple EPIYA-C segments might be reasons for low incidence of gastric cancer in Iran.

Distribution of Helicobacter pylori cagA, cagE, oipA and vacA in different major ethnic groups in Tehran, Iran

BACKGROUND AND AIM

There are geographical variations in Helicobacter pylori virulence genes; cagA, cagE, vacA and oipA. The present study compared the distribution of these genotypes in major ethnic groups residing in Tehran, Iran and their association with clinical outcomes.

METHODS

A total of 124 H. pylori-positive patients living in Tehran were enrolled in this study. The ethnic distribution was 74 Persians, 33 Turks and 17 other ethnics including Kurds, Lurs, Afghanis and Arabs. The presence of the cagA, cagE and oipA genes and vacA alleles (signal [s] and middle [m] region) were determined by polymerase chain reaction (PCR) from H. pylori DNA.

RESULTS

The cagA-positive status was predominant in all three ethnic groups (e.g. 65% in Persians and 73% in Turks). In contrast, the cagE-positive status was less than half in Persians (47%) and Turks (30%), whereas it was 77% in other ethnicities (P = 0.008). The predominant vacA genotypes were s1 and m1 in all three ethnic groups (e.g. 68% in Persians and 70% in Turks were s1). There was no significant association between cagA and cagE status or vacA genotypes and clinical outcomes. The oipA-positive strains were more common in non-ulcer dyspepsia (NUD) (63%) than in peptic ulcer patients (15%) (P = 0.001) in Persians, but the association was not observed in other ethnic groups.

CONCLUSION

There are some differences in the H. pylori genotypes among the ethnic groups in Iran. However, none of these markers seemed to be clinically helpful in predicting the clinical presentation of a H. pylori infection in Iran.