Study of the cytoxin-associated gene a (CagA gene) in Helicobacter pylori using gastric biopsies of Iraqi patients

Insights into the oral microbiota in human systemic cancers

The oral cavity stands as one of the pivotal interfaces facilitating the intricate interaction between the human body and the external environment. The impact of diverse oral microorganisms on the emergence and progression of various systemic cancers, typified by oral cancer, has garnered increasing attention. The potential pathogenicity of oral bacteria, notably the anaerobic Porphyromonas gingivalis and Fusobacterium nucleatum, has been extensively studied and exhibits obvious correlation with different carcinoma types. Furthermore, oral fungi and viruses are closely linked to oropharyngeal carcinoma. Multiple potential mechanisms of oral microbiota-induced carcinogenesis have been investigated, including heightened inflammatory responses, suppression of the host immune system, influence on the tumor microenvironment, anti-apoptotic activity, and promotion of malignant transformation. The disturbance of microbial equilibrium and the migration of oral microbiota play a pivotal role in facilitating oncogenic functions. This review aims to comprehensively outline the pathogenic mechanisms by which oral microbiota participate in carcinogenesis. Additionally, this review delves into their potential applications in cancer prevention, screening, and treatment. It proves to be a valuable resource for researchers investigating the intricate connection between oral microbiota and systemic cancers.

Diagnosis of Helicobacter pylori Infection in a Routine Testing Workflow: Effect of Bacterial Load and Virulence Factors

Reliable diagnostic methods are mandatory for effective management of Helicobacter pylori infection. Histology and culture are the most common invasive methods in current practice, even if molecular methods are gaining in importance. The performance of these conventional methods varies significantly. We conducted a retrospective study of 1540 adults and 504 children with gastric biopsies taken during endoscopy to assess the impact of bacterial load and the cagA virulence factor on the performance of H. pylori infection testing. The association between virulence and histology findings was also investigated. With 23S rRNA qPCR confirmed by glmM amplification as the gold standard, culture and histology had lower sensitivity, 74.4% and 73.3%, respectively. However, their sensitivity was enhanced (>90%) in biopsies with high bacterial load (qPCR Ct < 30). Positive cagA status of the strain was associated with high bacterial load (94.9%), thus resulting in more frequent positive culture (94.3%) and H. pylori histology detection (91.7%) and more severe lesions on histology (p < 0.001). Conversely, the cagA status of the strains was negative in 110/119 (92.4%) of biopsies with low bacterial load (qPCR Ct < 30), 82/90 (91.1%) with negative H. pylori histology detection and 119/131 (90%) with negative culture findings (p < 0.001). This study highlights the low sensitivity of conventional culture and histology that may lead to false negative diagnosis if used alone. H. pylori quantification associated with cagA genotyping in routine workflow are essential for a sensitive and reliable diagnosis, to identify patients at high risk and to manage eradication therapies.

EPIYA motifs of Helicobacter pylori cagA genotypes and gastrointestinal diseases in the Iranian population: a systematic review and meta-analysis

Helicobacter pylori is one of the best risk factors for gastric cancer. Recent studies have examined the relationship between virulence factors, in particular CagA toxin, and the development of gastrointestinal diseases. According to the literature, there is a significant relationship between the polymorphism of cagA-EPIYA motifs and progression to severe clinical outcomes. The main goal of our study was to determine the possible association between cagA genotypes and the risk of severe clinical outcomes in the Iranian population. We investigated these ambiguities using a comprehensive meta-analysis study, in which we evaluated data from 1762 Iranian patients for a potential correlation between all cagA gene genotypes and gastrointestinal diseases. According to statistical analysis, the frequencies of cagA genotypes including ABC, ABCC, AB and ABCCC in the Iranian population were estimated at 80.18%, 22.81%, 5.52% and 2.76%, respectively; the ABD genotype was not detected in these PCR-based studies. There was a significant relationship between cagA genotypes ABCC and ABCCC and severe clinical outcomes of infection such as peptic ulcer and gastric cancer. Overall, it can be concluded that there is a positive correlation with the number of copies of EPIYA-C and the increase of gastric cancer. Therefore, according to our results, it seems that the EPIYA-ABCCC motif has a strong positive relationship with gastric cancer in the Iranian population.

Pancreatic Cancer Meets Human Microbiota: Close Encounters of the Third Kind

Simple Summary

The microorganisms colonizing the epithelial surfaces of the human body, called microbiota, have been shown to influence the initiation, progression and response to therapy of many solid tumors, including pancreatic ductal adenocarcinoma, the most prominent form of pancreatic cancer. Here, we summarize the current knowledge about the influence of oral, gut and intratumoral microbiota on pancreatic ductal adenocarcinoma development and chemoresistance.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal types of cancer with a dismal prognosis. The five-year survival rate has not changed significantly in over 40 years. Current first-line treatments only offer a modest increase in overall survival in unselected populations, and there is an urgent need to personalize treatment in this aggressive disease and develop new therapeutic strategies. Evolving evidence suggests that the human microbiome impacts cancerogenesis and cancer resistance to therapy. The mechanism of action and interaction of microbiome and PDAC is still under investigation. Direct and indirect effects have been proposed, and the use of several microbiome signatures as predictive and prognostic biomarkers for pancreatic cancer are opening new therapeutic horizons. In this review, we provide an overview for the clinicians of studies describing the influence and associations of oral, gastrointestinal and intratumoral microbiota on PDAC development, progression and resistance to therapy and the potential use of microbiota as a diagnostic, prognostic and predictive biomarker for PDAC.

Microbes in Tumoral In Situ Tissues and in Tumorigenesis

Cancerous tumors are severe diseases affecting human health that have a complicated etiology and pathogenesis. Microbes have been considered to be related to the development and progression of numerous tumors through various pathogenic mechanisms in recent studies. Bacteria, which have so far remained the most studied microbes worldwide, have four major possible special pathogenic mechanisms (modulation of inflammation, immunity, DNA damage, and metabolism) that are related to carcinogenesis. This review aims to macroscopically summarize and verify the relationships between microbes and tumoral in situ tissues from cancers of four major different systems (urinary, respiratory, digestive, and reproductive); the abovementioned four microbial pathogenic mechanisms, as well as some synergistic pathogenic mechanisms, are also discussed. Once the etiologic role of microbes and their precise pathogenic mechanisms in carcinogenesis are known, the early prevention, diagnosis, and treatment of cancers would progress significantly.

Characteristics of Helicobacter pylori strains isolated from Mauritanian patients

BACKGROUND

Helicobacter pylori (H pylori) is responsible for various diseases including cancer It co-evolved with humans, and human migrations shaped the expansion and the diversity of strains around the world. The risk of developing a disease depends on virulence factors, mainly the cytotoxin-associated gene A protein (CagA). The aim of this study was to determine the cagA status in H pylori strains from Mauritanian patients and to search for a relationship with endoscopic and histologic findings.

MATERIAL AND METHODS

H pylori was searched in gastric biopsies taken during endoscopy in patients with gastro-duodenal symptoms. RT-PCR was used for the diagnosis and resistance to clarithromycin. The cagA status was determined with PCR and the EPIYA-cagA polymorphism with sequencing.

RESULTS

At all, 76/78 (97.4%) biopsies were positive. The rate of clarithromycin resistance was 4/76 (5.26%) due to the A2143G mutation, with a mixed population in 2 cases. The cagA gene was present in 23/76 (30.26%) biopsies, and the EPIYA motif was ABC in 21 (91.3%). High bacterial load and inflammation were significantly associated with cagA-positive status (P < .01). Phylogenetic analysis of the glmM and hspA genes highlighted a mixture of African and European genes in strains of H pylori isolated from patients of Moor origin.

CONCLUSION

We report a high prevalence of H pylori infection in Mauritanian patients, a low rate of clarithromycin resistance (5.26%) and high bacterial load and inflammation associated with cagA-positive status. The phylogenetic analysis highlights the mix of different populations leading to the Moor ethnicity.

Determination of CagA EPIYA motif in Helicobacter pylori strains isolated from patients with digestive disorder

This study was conducted to identify patterns of cagA EPIYA motifs in H. pylori strains isolated from patients with gastrointestinal diseases in Hospitals of Shahrekord, and investigate the association between these biomarkers and clinical outcomes of gastrointestinal diseases due to H. pylori. In this study, 253 patients with gastrointestinal diseases were studied within 1395–1396. Histopathological investigations and urease test showed that 207 isolates were H. pylori-positive. Then, screening using a molecular technique, PCR, confirmed that 159 isolates had cagA. Finally, the pattern and prevalence of the motifs were determined by PCR and identified a number of motifs were sequenced.

Results of this study showed that the pattern of motifs was as follows: ABC (140 isolates) (93/7%), ABCC (6 isolates) (3/77%), ABCCC (4 isolates) (2/5%), AB (7 isolates) (4/4%), AC (1 isolate) (0/6%), and BC (1 isolate) (0/6%). Sequencing results showed the presence of changed EPIYA motif in some isolates. CM motif sequence was also seen in all isolates. In this study, no significant association was seen between the prevalence rate of different patterns and clinical symptoms (p = 0.71). There is a slight association between the presence of ABC motifs and the type of digestive disorder (p = 0.056). Results indicated that ABC was the most frequently seen pattern however, in such that positive cases of ABC motifs were more common in gastritis. All isolates had kinase phosphorylation region, and the observed pattern in this region was a generally western type (ABC).

cagA gene EPIYA motif genetic characterization from Colombian Helicobacter pylori isolates: Standardization of a molecular test for rapid clinical laboratory detection

The aim of this work was to determine current cagA gene EPIYA motifs present in Colombian Helicobacter pylori isolates using a fast and reliable molecular test. DNA from eighty-five Helicobacter pylori-cagA positive strains were analyzed. Strains were obtained from patients diagnosed with functional dyspepsia at Clínica Fundadores in Bogotá. The 3' region of the cagA gene was amplified through conventional Polymerase Chain Reaction (PCR). Obtained amplicons were sequenced using the Sanger method and analyzed with bioinformatics tools. Additionally, a significant Spearman correlation coefficient was determined between the patients' age and the number of EPIYA-C repeats; with p values < 0.05 considered significant. Estimates were obtained using a 95% CI. The 3´ variable region of the cagA gene was amplified and PCR products of the following sizes corresponded to the following EPIYA motifs: 400 bp: EPIYA AB, 500 bp: EPIYA ABC, 600 bp: EPIYA ABCC and 700 bp: ABCCC. A single PCR band was observed for 58 out of 85 Helicobacter pylori isolates, with an EPIYA distribution motif as follows: 7/85 AB (8.2%), 34/85 ABC (40%), 26/85 ABCC (30.6%) and 18/85 ABCCC (21.2%). However, in 27 out of 85 Helicobacter pylori isolates, two or more bands were observed, where the most predominant cagA genotype were ABC-ABCC (26%, 7/27) and ABCC-ABCCC (22.2%, 6/27). A direct proportionality between the number of EPIYA-C repeats and an increase in the patients’ age was observed, finding a greater number of EPIYA ABCC and ABCCC repeats in the population over 50 years old. All isolates were of the Western cagA type and 51.8% of them were found to have multiple EPIYA-C repeats. These standardized molecular test allowed to identify the number of EPIYA C motifs based on band size.

Role of the microbiome in occurrence, development and treatment of pancreatic cancer

Pancreatic cancer is one of the most lethal malignancies. Recent studies indicated that development of pancreatic cancer may be intimately connected with the microbiome. In this review, we discuss the mechanisms through which microbiomes affect the development of pancreatic cancer, including inflammation and immunomodulation. Potential therapeutic and diagnostic applications of microbiomes are also discussed. For example, microbiomes may serve as diagnostic markers for pancreatic cancer, and may also play an important role in determining the efficacies of treatments such as chemo- and immunotherapies. Future studies will provide additional insights into the various roles of microbiomes in pancreatic cancer.

Association Between Gastric Lymphoid Follicles (Precursor Of MALT Lymphomas) And H. pylori Infection At A Referral Hospital In Iran

Purpose

Mucosa-associated lymphoid tissue (MALT) is the most common endoscopic finding in Helicobacter pylori positive patients that can progress to MALT lymphoma after a prolonged antigenic contact. This study was aimed to evaluate the prevalence of lymphoid follicles and aggregates (precursors of MALT lymphomas) in gastric mucosal biopsies and their correlation with H. pylori infection.

Patients and methods

In this study, 100 patients who had undergone an upper gastrointestinal endoscopy were enrolled. Five biopsy specimens were taken each patient through screening endoscopy and histopathological changes were evaluated and graded using the Wotherspoon System. The clinical background and H. pylori infection status were also investigated.

Results

Among the 100 cases in our series, 79 patients (79%) showed evidence of MALT in at least one biopsy specimen taken from the stomach and 21 cases (21%) had no evidence of MALT. H. pylori infection was detected in 74 (74%) patients. Lymphoid follicles were detected more frequently in H. pylori-positive patients (59%) compared to H. pylori-negative cases (3%) (P<0.001).

Conclusion

The frequency of lymphoid follicles and aggregates in gastric mucosal is associated with H. pylori infection. Further community-based studies in larger sample sizes using a combination of microscopic methods and PCR assay are required for effective monitoring of H. pylori infection.

The microbiota and microbiome in pancreatic cancer: more influential than expected

Microbiota is just beginning to be recognized as an important player in carcinogenesis and the interplay among microbes is greater than expected. Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease for which mortality closely parallels incidence. Early detection would provide the best opportunity to increase survival rates. Specific well-studied oral, gastrointestinal, and intrapancreatic microbes and some kinds of hepatotropic viruses and bactibilia may have potential etiological roles in pancreatic carcinogenesis, or modulating individual responses to oncotherapy. Concrete mechanisms mainly involve perpetuating inflammation, regulating the immune system-microbe-tumor axis, affecting metabolism, and altering the tumor microenvironment. The revolutionary technology of omics has generated insight into cancer microbiomes. A better understanding of the microbiota in PDAC might lead to the establishment of screening or early-stage diagnosis methods, implementation of cancer bacteriotherapy, adjustment of therapeutic efficacy even alleviating the adverse effects, creating new opportunities and fostering hope for desperate PDAC patients.

Helicobacter pylori CagA EPIYA-C motifs and gastric diseases in Moroccan patients

BACKGROUND

The pathogenicity of cagA-positive H. pylori strains is associated with the number and type of repeated sequences named EPIYA located in the C-terminal region of the CagA protein. The aim of this study is to determine the polymorphism of the H. pylori cagA 3' region circulating in Morocco and its association with different gastric pathologies.

METHODS

A total of 1353 consenting patients, were recruited in this study. The gastric biopsies performed during endoscopy were used for histological examination and for molecular characterization of H. pylori. The study of the type and number of "EPIYA" motif was identified by PCR directly on H. pylori positive biopsies.

RESULTS

Of all the biopsies, the infection rate was 61.1%. The cagA gene was amplified in 68.9% of the cases and the analysis of the 3' region of cagA showed the exclusive presence of the "Western CagA" type with a predominance of the EPIYA-ABC motif (71.4%). The number of EPIYA-C motif varies from 0 to 2. The multinomial analysis shows that the infection with strains of H. pylori having two EPIYA-C motifs is a factor that increases the risk of developing gastric cancer compared to gastritis cases with strains lacking this motif (OR = 11.64; CI: 3.34-45.15), whereas this risk is 6 fold higher in comparison with duodenal ulcer cases (OR = 6, CI: 1.29-27.76).

CONCLUSIONS

The results of this study suggest that the number of EPIYA-C motifs might be useful as a predictive marker of the infection evolution and will help in the identification of patients at high risk of developing gastric cancer.

Prevalence of Specific Helicobacter PyloricagA, vacA, iceA, ureC Genotypes and its Clinical Relevance in the Patients with Acid-Peptic Diseases

INTRODUCTION

Virulent markers of H. pylori, the vacuolating cytotoxin (vacA), cytotoxin-associated gene A (cagA), induced by contact with epithelium factor antigen (iceA gene) and the urease C gene (ureC) may plays a major role in determining the clinical outcome of Helicobacter infections.

AIM

To detect the prevalence of the cagA, vacA, ureC and iceA genotypes of H. pylori from antral biopsy specimens of patients and to associate its role in specific disease.

MATERIALS AND METHODS

The study was conducted at Department of Microbiology of Shree P.M. Patel College of Paramedical Sciences, Anand, Gujarat, India. Seventy one antral biopsies of symptomatic patients referred for endoscopy from October 2012 to September 2013 were subjected to Multiplex PCR. DNA isolation from 71 biopsy samples was done by using "QIAamp DNA mini kit" from QIAGEN (GmbH, Hilden, Germany). Data was analysed using Chi square (χ²) test and p-value<0.05 was considered significant.

RESULTS

Out of the 71 biopsies screened, 22(31%) samples were positive for H. pylori by PCR, with high proportion of cagA positive (17/22 specimen; 77.27%), followed by ureC positive (4/22 specimen; 18.18%) and vacA positive (1/22 specimen; 4.54%) strains. Significant association was found between cagA and female gender (p-value=0.042). Out of 17 cagA positive strains, 9(52.94%) were found in patients with gastritis, 5(29.41%) in reflux oesophagitis and 3(17.64%) in patients with diodenal ulcer. We found 0% prevalence of iceA gene; conversely we had three peptic ulcer patients with only cagA positivity.

CONCLUSION

The cagA positive strain mainly affects the patients with gastritis specifically of female gender and iceA genotype is not a useful marker associated with peptic ulcer disease. Patients should be screened for cagA genotype when reported to be a case of gastritis for early treatment to prevent further complications such as cancer.

Survival of Helicobacter pylori in gastric acidic territory

BACKGROUND

Helicobacter pylori is well adapted to colonize the epithelial surface of the human gastric mucosa and can cause persistent infections. In order to infect the gastric mucosa, it has to survive in the gastric acidic pH. This organism has well developed mechanisms to neutralize the effects of acidic pH.

OBJECTIVE

This review article was designed to summarize the various functional and molecular aspects by which the bacterium can combat and survive the gastric acidic pH in order to establish the persistent infections.

METHODS

We used the keywords (acid acclimation, gastric acidic environment, H. pylori and survival) in combination or alone for pubmed search of recent scientific literatures. One hundred and forty one papers published between 1989 and 2016 were sorted out. The articles published with only abstracts, other than in English language, case reports and reviews were excluded.

RESULTS

Many literatures describing the role of several factors in acid survival were found. Recently, the role of several other factors has been claimed to participate in acid survival.

CONCLUSION

In conclusion, this organism has well characterized mechanisms for acid survival.

Association of CagA EPIYA-D or EPIYA-C phosphorylation sites with peptic ulcer and gastric cancer risks: A meta-analysis

BACKGROUND

Increasingly, studies have focused on the relationship between Helicobacter pylori (H pylori) cytotoxin associated gene A protein (CagA) Glu-Pro-Ile-Tyr-Ala (EPIYA)-D motifs or multiple EPIYA-C phosphorylation sites and peptic ulcer disease (PUD) or gastric cancer (GC) risk. However, the conclusions have been inconsistent. The aim of this meta-analysis was to evaluate whether 1 CagA EPIYA-D motif or multiple EPIYA-C phosphorylation sites were associated with PUD or GC risk.

MATERIALS AND METHODS

A literature search was performed in PubMed, Web of Science, Wanfang Data, Excerpt Medica Database, and the Chinese National Knowledge Infrastructure database to identify eligible research. We analyzed the odds ratios (OR) and 95% confidence intervals (CI) to assess the strength of association.

RESULTS

Compared with 1 EPIYA-C motif in Asian populations, 1 EPIYA-D site was associated with an increased GC risk (OR=1.91, 95% CI=1.19-3.07, P = .008). However, 1 EPIYA-D motif was not significantly associated with PUD (OR = 0.90, 95% CI = 0.46-1.76, P = .764), gastric ulcer (GU) (OR = 0.85, 95% CI = 0.27-2.63, P = .771), or duodenal ulcer (DU) (OR = 0.89, 95% CI = 0.25-3.16, P = .859) risk. Compared with no more than 1 EPIYA-C motif, multiple motifs were associated with increased PUD (OR = 2.33, 95% CI = 1.29-4.20, P = .005) and DU (OR = 2.32, 95% CI = 1.08-5.00, P = .031) risk in Asia and GC risk in the United States and Europe (OR = 3.28, 95% CI = 2.32-4.64, P < .001). Multiple EPIYA-C sites were not associated with GU risk (OR = 4.54, 95% CI = 0.95-21.83, P = .059). There was no publication bias identified in these comparisons.

CONCLUSIONS

In Asia, 1 EPIYA-D motif was significantly associated with increased GC risk. Multiple EPIYA-C motifs were associated with increased PUD and DU risk, particularly in Asia. In the United States and Europe, multiple EPIYA-C motifs were associated with increased GC risk. Therefore, detection of polymorphic CagA EPIYA motifs may improve clinical prediction of disease risk.

Microbiome and pancreatic cancer: A comprehensive topic review of literature

AIM

To review microbiome alterations associated with pancreatic cancer, its potential utility in diagnostics, risk assessment, and influence on disease outcomes.

METHODS

A comprehensive literature review was conducted by all-inclusive topic review from PubMed, MEDLINE, and Web of Science. The last search was performed in October 2016.

RESULTS

Diverse microbiome alterations exist among several body sites including oral, gut, and pancreatic tissue, in patients with pancreatic cancer compared to healthy populations.

CONCLUSION

Pilot study successes in non-invasive screening strategies warrant further investigation for future translational application in early diagnostics and to learn modifiable risk factors relevant to disease prevention. Pre-clinical investigations exist in other tumor types that suggest microbiome manipulation provides opportunity to favorably transform cancer response to existing treatment protocols and improve survival.

Role of Helicobacter pylori infection in pathogenesis of gastric carcinoma

Gastric cancer (GC) is one of the most common carcinoma and the second leading cause of cancer-related deaths worldwide. Helicobacter pylori (H. pylori) infection causes a series of precancerous lesions like gastritis, atrophy, intestinal metaplasia and dysplasia, and is the strongest known risk factor for GC, as supported by epidemiological, preclinical and clinical studies. However, the mechanism of H. pylori developing gastric carcinoma has not been well defined. Among infected individuals, approximately 10% develop severe gastric lesions such as peptic ulcer disease, 1%-3% progresses to GC. The outcomes of H. pylori infection are determined by bacterial virulence, genetic polymorphism of hosts as well as environmental factors. It is important to gain further understanding of the pathogenesis of H. pylori infection for developing more effective treatments for this common but deadly malignancy. The recent findings on the bacterial virulence factors, effects of H. pylori on epithelial cells, genetic polymorphism of both the bacterium and its host, and the environmental factors for GC are discussed with focus on the role of H. pylori in gastric carcinogenesis in this review.

Helicobacter pylori bab Paralog Distribution and Association with cagA, vacA, and homA/B Genotypes in American and South Korean Clinical Isolates

Helicobacter pylori genetic variation is a crucial component of colonization and persistence within the inhospitable niche of the gastric mucosa. As such, numerous H. pylori genes have been shown to vary in terms of presence and genomic location within this pathogen. Among the variable factors, the Bab family of outer membrane proteins (OMPs) has been shown to differ within subsets of strains. To better understand genetic variation among the bab genes and to determine whether this variation differed among isolates obtained from different geographic locations, we characterized the distribution of the Bab family members in 80 American H. pylori clinical isolates (AH) and 80 South Korean H. pylori clinical isolates (KH). Overall, we identified 23 different bab genotypes (19 in AH and 11 in KH), but only 5 occurred in greater than 5 isolates. Regardless of strain origin, a strain in which locus A and locus B were both occupied by a bab gene was the most common (85%); locus C was only occupied in those isolates that carried bab paralog at locus A and B. While the babA/babB/- genotype predominated in the KH (78.8%), no single genotype could account for greater than 40% in the AH collection. In addition to basic genotyping, we also identified associations between bab genotype and well known virulence factors cagA and vacA. Specifically, significant associations between babA at locus A and the cagA EPIYA-ABD motif (P<0.0001) and the vacA s1/i1/m1 allele (P<0.0001) were identified. Log-linear modeling further revealed a three-way association between bab carried at locus A, vacA, and number of OMPs from the HOM family (P<0.002). En masse this study provides a detailed characterization of the bab genotypes from two distinct populations. Our analysis suggests greater variability in the AH, perhaps due to adaptation to a more diverse host population. Furthermore, when considering the presence or absence of both the bab and homA/B paralogs at their given loci and the vacA genotype, an association was observed. Our results highlight the multifactorial nature of H. pylori mediated disease and the importance of considering how the specific combinations of H. pylori virulence genes and their multiple interactions with the host will collectively impact disease progression.

Patterns of EPIYA motifs among cagA-positive Helicobacter pylori strains: a case-control study in a Turkish population with Eurasian geographical features

Geographical variation in the frequency of various gastroduodenal pathologies was shown to be related to the geographical diversity of H. pylori CagA Glu-Pro-Ile-Tyr-Ala (EPIYA) patterns. We examined the EPIYA patterns of H. pylori and the association of EPIYA patterns with gastric cancer (GC) for the first time, to the best of our knowledge, in Turkey. The patient group (PG) contained 60 patients [38 GC and 22 duodenal ulcer (DU) patients]. The control group (CG) was 110 individuals [94 gastritis patients and 16 persons with a normal gastrointestinal system (NGIS)]. Specific primers were used for the detection of cagA including empty-site-positive and EPIYA-A, -B, -C, -D PCR. Bands of EPIYA-A, -B, -C were confirmed by DNA sequencing. One hundred and forty-two (83.5 %) strains [60 in the PG (38 GC, 22 DU), 82 in the CG (72 gastritis, 10 NGIS)] were positive for the cagA gene. EPIYA-C with multiple repeats was detected in 34 (23.9 %) strains, and 22 (64.7 %) were from GC patients. EPIYA-C with one repeat was detected in 89 (62.7 %) strains, and 54 (60.7 %) were from gastritis patients. EPIYT was detected in 10 strains, and EPIYA-D was not detected. The number of EPIYA-C with multiple repeats was significantly higher for the PG than for the CG (P < 0.0001). In GC patients, the number of EPIYA-C with multiple repeats was significantly higher than one repeat (P < 0.0001). In conclusion, our study showed that multiple EPIYA-C repeats increases the GC risk by 30.6-fold and the DU risk by 8.9-fold versus the CG. This indicates that Western-type H. pylori strains in Turkey have similar EPIYA motifs to those of neighbouring countries and Western populations.

Different distribution of Helicobacter pylori EPIYA- cagA motifs and dupA genes in the upper gastrointestinal diseases and correlation with clinical outcomes in iranian patients

AIM

Our aim was to determine the EPIYA-cagA Phosphorylation sites and dupA gene in H. pylori isolates among patients with upper gastrointestinal diseases.

BACKGROUND

Pathogenicity of the cagA-positive Helicobacter pylori is associated with EPIYA motifs and higher number of EPIYA-C segments is a risk factor of gastric cancer, while duodenal ulcer-promoting gene (dupA) is determined as a protective factor against gastric cancer.

PATIENTS AND METHODS

A total of 280 non-repeated gastric biopsies obtained from patients undergoing endoscopy from January 2013 till July 2013. Samples were cultured on selective horse blood agar and incubated in microaerophilic atmosphere. The isolated organisms were identified as H. pylori by Gram staining and positive oxidase, catalase, and urease tests. Various motif types of cagA and the prevalence of dupA were determined by PCR method.

RESULTS

Out of 280 specimens, 128 (54.7%) isolated organisms were identified as H. pylori. Of 120 H. pylori isolates, 35.9% were dupA positive and 56.26% were cagA positive, while cagA with ABC and ABCC motifs were 55.5% and 44.5%, respectively. Fifty six percent of the isolates with the ABCC motif have had dupA genes. We also found a significant association between strains with genotypes of dupA-ABC and duodenal ulcer disease (p = 0.007).

CONCLUSION

The results of this study showed that the prevalence of cagA-positive H. pylori in Shiraz was as high as in western countries and higher numbers of EPIYA-C segments were seen in gastric cancer patients. We may also use dupA as a prognostic and pathogenic marker for duodenal ulcer disease and cagA with the segment C for gastric cancer and gastric ulcer disease in this region.