Helicobacter pylori genotypes associated with gastric histo-pathological damages in a Moroccan population

Gastric Cancer and Associated Pathogens: Is There Any Association in the Moroccan Region?

Helicobacter pylori, Epstein-Barr virus (EBV), and human papillomavirus (HPV) are three pathogens associated with various human cancers. This study aimed to investigate the role of these pathogens in gastric cancer in a Moroccan population. A retrospective study was conducted with participants attending the Gastroenterology Department of Hassan II University Hospital in Fez. In total, 279 participants were enrolled in this study. Helicobacter pylori, EBV, and HPV were detected and genotyped using polymerase chain reaction. Significant associations have been established between H. pylori and EBV and gastric cancer. A total of 93.4% and 43.3% of gastric cancer cases were related to H. pylori and EBV, respectively (P ≤ 0.01). Helicobacter pylori-EBV co-infection was responsible for 31.6% of gastric cancer cases (P < 0.01). Correlation between pathogen genotypes and gastric cancer showed that 54.6% of gastric cancer EBV positive cases had a 30 bp deletion in the LMP1 gene, whereas 16% of gastric cancer cases had high-risk HPV genotypes (P = 0.21). These results highlight the possible role of co-infection in gastric cancer development.

Helicobacter pylori vacA Allelic Combination, dupA, cagE and cagA Genotypes and Their Associations with Gastric Diseases in the Moroccan Population

This study aimed to investigate the combination of the four regions of Helicobacter pylori vacA with cagA, cagE, dupA genes and cagA-EPIYA motifs to identify the most likely combination that could be used as a disease determinant marker in the Moroccan population. A total of 838 H. pylori-positive samples were obtained from consenting patients, that were previously analyzed by PCR to characterize vacA-s, -m, and -i regions; cagE status; and cagA 3' region polymorphism, were used to characterize vacA-d region and to determine dupA gene status. The analysis showed the predominance of the less virulent combination {vacA(s2m2i2d2)dupA(-)cagE(-)cagA(-)}, and showed that the risk of gastric cancer is 13.33 fold higher (95% confidence interval [CI] = 1.06-166.37) in patients infected with strains harboring vacA(s1m1i1d1)dupA(-)cagE(+)cagA(2EPIYA-C) compared to patients with gastritis without lesions and infected by H. pylori strains harboring vacA(s2m2i2d2)dupA(-) cagE(-)cagA(-). Infection with strains harboring the vacA(s1m1i1d1)dupA(+)cagE(+)cagA(1EPIYA-C) genotype combination represented a risk factor for both gastric ulcer and duodenal ulcer than gastritis without lesions; odds ratio (OR) =16 (95% CI = 1.09-234.24) and OR = 12.39 (95% CI = 1.09-140.81), respectively. These results suggest that the combination of the active form of vacA genotypes, dupA gene status, and the number of EPIYA-C motifs may be helpful markers for discriminating between several gastric diseases.

The global prevalence of gastric cancer in Helicobacter pylori-infected individuals: a systematic review and meta-analysis

BACKGROUND

Helicobacter pylori is a gastrointestinal pathogen that infects around half of the world's population. H. pylori infection is the most severe known risk factor for gastric cancer (GC), which is the second highest cause of cancer-related deaths globally. We conducted a systematic review and meta-analysis to assess the global prevalence of GC in H. pylori-infected individuals.

METHODS

We performed a systematic search of the PubMed, Web of Science, and Embase databases for studies of the prevalence of GC in H. pylori-infected individuals published from 1 January 2011 to 20 April 2021. Metaprop package were used to calculate the pooled prevalence with 95% confidence interval. Random-effects model was applied to estimate the pooled prevalence. We also quantified it with the I2 index. Based on the Higgins classification approach, I2 values above 0.7 were determined as high heterogeneity.

RESULTS

Among 17,438 reports screened, we assessed 1053 full-text articles for eligibility; 149 were included in the final analysis, comprising data from 32 countries. The highest and lowest prevalence was observed in America (pooled prevalence: 18.06%; 95% CI: 16.48 - 19.63; I2: 98.84%) and Africa (pooled prevalence: 9.52%; 95% CI: 5.92 - 13.12; I2: 88.39%). Among individual countries, Japan had the highest pooled prevalence of GC in H. pylori positive patients (Prevalence: 90.90%:95% CI: 83.61-95.14), whereas Sweden had the lowest prevalence (Prevalence: 0.07%; 95% CI: 0.06-0.09). The highest and lowest prevalence was observed in prospective case series (pooled prevalence: 23.13%; 95% CI: 20.41 - 25.85; I2: 97.70%) and retrospective cohort (pooled prevalence: 1.17%; 95% CI: 0.55 - 1.78; I 2: 0.10%).

CONCLUSIONS

H. pylori infection in GC patients varied between regions in this systematic review and meta-analysis. We observed that large amounts of GCs in developed countries are associated with H. pylori. Using these data, regional initiatives can be taken to prevent and eradicate H. pylori worldwide, thus reducing its complications.

Exploring the potential of Cinnamomum zeylanicum oil against drug resistant Helicobacter pylori-producing cytotoxic genes

Thirty-one of sixty dyspeptic patients tested positive for Helicobacter pylori colonization in this study, as determined by histopathology and 16S rRNA. The cytotoxin-associated gene A (cagA) and vacuolating cytotoxin A (vacA) genes were found in 67.7 and 93.5% of H. pylori patients, respectively. The cagA gene was found to be associated with 100% of patients with duodenal erosion and ulceration identified via endoscopy examination. In addition, 86.7% of patients with cancerous and precancerous lesions, glandular atrophy, and intestinal metaplasia identified via histopathology examination. The vacA s1m1 mutation was associated with more severe forms of gastric erosion and ulceration, as well as the presence of precancerous and cancerous lesions. Eighteen (64.3%) of the twenty-eight isolates were classified as multi-drug resistant (MDR) or pan-drug resistant (PDR) H. pylori. Due to a resurgence of interest in alternative therapies derived from plants as a result of H. pylori resistance to the majority of commonly used antibiotics, the inhibitory activity of five essential oils extracted from some commonly used medicinal plants was evaluated in vitro against drug-resistant H. pylori clinical isolates. Cinnamomum zeylanicum essential oil demonstrated the highest anti-H. pylori activity when compared to the other essential oils tested. Cinnamaldehyde was the most abundant compound in C. zeylanicum (65.91%). The toxicological evaluation established the safety of C. zeylanicum oil for human use. As a result, C. zeylanicum essential oil may represent a novel antibacterial agent capable of combating drug-resistant H. pylori carrying cytotoxin genes.

Association of cagA, cagC, virB2, and vacA Subtypes of Helicobacter pylori with Adenocarcinoma Development in Iranian Patients

Background: Gastric cancer has been introduced as the second cause of cancer death worldwide. Helicobacter pylori infection is considered one of the main risk factors for this type of cancer, so that it has been classified as group I carcinogens. Objectives: The present research intended to examine the prevalence of cagA, cagC, virB2, vacA, and genotype distribution in H. pylori-infected biopsies and adenocarcinoma cases. Methods: Thirty-four H. pylori gastric biopsies taken from Western Iranian patients that were diagnosed as gastritis, gastric ulcers, and adenocarcinoma were used in this study. Two samples were taken from each patient. These samples were selected based on endoscopic observations and histological examinations. The presence of H. pylori was confirmed by the Rapid Urease test (RUT) and the ureC gene by the polymerase chain reaction (PCR) technique. Then, specific primers for vacA and cagPAI were used for genotyping H. pylori by PCR-typing. Results: The obtained results showed that 86.8% of the samples were H. pylori-positive. Moreover, the cagA gene prevalence was 51.50% in the samples. In addition, the adenocarcinoma outcome was significantly related to all selected genes. Likewise, some gastric diseases such as gastric ulcers, duodenal ulcer (DU), gastritis, lymphoid, and gastroesophageal reflux disease (GERD) were observed in adenocarcinoma cases. It was also found that the vacAs1m1i1 genotype plays an important role in gastric malignancies. The most frequent vacA genotype in the H. pylori-infected isolates was s1m1i1, and the observed frequency of vacA and cagA genes in adenocarcinoma was statistically significant. Conclusions: The findings showed that H. pylori vacA and cagA gene virulence factors are associated with adenocarcinoma in Western Iranian patients.

VacA genotypes and cagA-EPIYA-C motifs of Helicobacter pylori and gastric histopathological lesions

Helicobacter pylori infection induces inflammation of the gastric mucosa, which may progress to precancerous lesions and gastric cancer. The gastric histo-pathological damages may be associated with some virulence genes of the bacterium, notably vacA and cagA genes. To establish correlations between these genes and the lesions, biopsies from 1303 adults consenting patients that were previously analyzed by PCR to characterize vacA-s vacA-m, vacA-i regions and cagA 3' region polymorphism, were used. The highest average age was obtained in patients with intestinal metaplasia (53.65 ± 15.26 years) and gastric cancer (53.60 ± 14.32 years). Thus, these lesions are more frequent in elderly and male subjects. Tobacco smoking was significantly associated with neutrophilic activity (P = .02). No significant association was obtained between patients with chronic inflammation and vacA and cagA H. pylori genotypes. However, a significant association has been obtained between this lesion and cagA+ in aged patients (P = .02), while intestinal metaplasia was significantly associated with vacAi1 and vacAm1 separately (P < .01 and .01). Also, a significant association was obtained between intestinal metaplasia and strains with one EPIYA-C motif in young patients (P = .001). Interestingly, a significant association was obtained between gastric cancer and cagA+, vacAi1, vacAm1 H. pylori genotypes and also with two EPIYA-C motifs independently of age groups (all P < .05). The results of our study show that H. pylori vacAi1 could be more potent than the other H. pylori virulent factors for predicting the precancerous gastric lesions, confirming that this gene may be helpful to identify patients at high risk for gastric cancer.

Gastric IL-1β, IL-8, and IL-17A expression in Moroccan patients infected with Helicobacter pylori may be a predictive signature of severe pathological stages

INTRODUCTION

Helicobacter pylori induces acute gastritis that can progress to serious diseases such as gastric cancer. H. pylori interacts with host cells within the gastric mucosa, resulting in activation of multiple innate immune signalling pathways, leading to pro-inflammatory cytokines production and immune cells recruitment. Various studies have shown that there are ethnic- and population-related differences in the expression of these cytokines. Although the H. pylori infection is a major public health problem in Morocco, to our knowledge, no study has been carried out in gastric cytokine expression from H. pylori-infected Moroccan patients. Thus we aimed to (i) determine the IL-1β, IL-8 and IL-17A gene expression in gastric biopsies from Moroccan patients infected with H. pylori, and (ii) to determine the cytokine signature of each pathological stages associated with this infection.

MATERIAL AND METHODS

71 patients with epigastralgic pain were included in this study. The H. pylori detection on gastric biopsies was performed by histopathological and PCR analysis. The IL-1β, IL-8 and IL-17A mRNA expression in the antrun and fundus biopsies was performed by RT-qPCR.

RESULTS

The histopathological and PCR analyses revealed that 87.32% of the patients were infected with H. pylori. IL-1β mRNA expression was significantly lower in the antral mucosa of H. pylori-infected patients (p = 0.0038) than in the uninfected while there was no significant difference in the expression of IL-8 and IL-17A mRNA. The expression of the three cytokines was higher in the fundic mucosa of H. pylori-infected patients than in the uninfected patients, but only IL-8 and IL-17A expression reached statistical significance (p = 0.042 and p = 0.0179 respectively). Furthermore, the multivariate predictive analysis highlighted a cytokine signature that may predict metaplasia during the infection progression that involves a specific down-regulation of IL17A and an up-regulation of IL1β in antral and fundic metaplasia respectively.

Syzygium aromaticum L.: Traditional herbal medicine against cagA and vacA toxin genes-producing drug resistant Helicobacter pylori

The Pan-Drug Resistant (PDR), Helicobacter pylori remains an intractable challenge in public health worldwide and this pathogenicity is mainly due to the presence of a cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA). On the other hand, plant extracts such as Syzygium aromaticum contain a diverse array of secondary metabolites, which could be potentially used to combat H. pylori pathogens. To our knowledge, this is the first report on the biomedical potential of S. aromaticum extract against cytotoxin-associated genes producing PDR H. pylori. In this investigation, out of 45 gastric antral biopsy specimens of dyspeptic patients, 20 strains were confirmed as H. pylori. Eight (40%) out of 20 strains were PDR H. pylori while the rest of the strains were Multi-Drug Resistant (MDR) strains. Genotypic analyses of PDR H. pylori strains showed that cagA and vacA genes were found to be 75% and 87.5%, respectively and m2s2 was the most common subtype of vacA gene. S. aromaticum showed a significant higher anti-H. pylori activity compared to that of Cinnamomum zeylanicum and Thymus vulgaris. Eugenol was the major phenolic compound (28.14%) detected in the methanolic extract of S. aromaticum. Clearly, results of the toxicological assessment confirmed the safety of S. aromaticum for use. Hence, these results suggest that S. aromaticum could be a new useful natural antimicrobial agent that could potentially combat cytotoxin genes-producing drug-resistant H. pylori. Moreover, these findings provide a scientific basis for the development of antimicrobial agents from traditional herbal medicines for gastroprotection against gastric ulcer.

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Helicobacter pylori remains an intractable challenge in public health worldwide.

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CagA and VacA genes are H. pylori pathogenicity dependent.

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Eight strains of H. pylori were proven to pan-drug resistant.

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The cagA and vacA genes were found to be 75% and 87.5%, respectively.

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Syzygium aromaticum extract showed a significant higher anti-H. pylori activity.

Helicobacter pylori vacA, cagA and iceA genotypes in dyspeptic patients from southwestern region, Saudi Arabia: distribution and association with clinical outcomes and histopathological changes

Background

The aim of this study was to identify the common H. pylori virulence genes among dyspeptic Southwestern Saudi patients and their association with clinical outcomes and histopathological findings to help practitioners and researchers in the region for better management of infections caused by such bacteria.

Methods

Four hundred two gastric biopsy specimens were analyzed using histopathological examination and real time-PCR. The positive 187 specimens by RT-PCR were genotyped using PCR targeting cagA, vacA and iceA genes.

Results

One hundred twenty-eight gastric biopsy specimens were positive in genotyping PCRs. The cagA, vacA, iceA1 and iceA2 genes were detected in rates of 49.2% (63/128), 100%(128/128), 42.2% (54/128), 32.8% (42/128), respectively. The vacA s1as1bm2 subtype was the highest 23.4% (30/128), followed by m2 and s1a1b subtypes which were equally detected [16.4% (21/128) for each]. The iceA genes were significantly associated with gastritis and gastric ulcer. Overall, vacA genotypes were significantly associated with gastritis, gastric and duodenal ulcers. The vacA subtypes: s1as1bm2, s1a1b and s2 m2 showed chronic active gastritis in percentages of 90.0, 81, and 84.2%, respectively. All vacA mixed genotypes showed chronic active gastritis.

Conclusions

H. pylori virulence genes are highly prevalent and diverse among patients with dyspepsia in Southwestern region of Saudi Arabia. The iceA genes and the different vacA subtypes are significantly associated with the clinical outcomes and histopathological changes especially chronic active gastritis.

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.

High prevalence of gastric intestinal metaplasia detected by confocal laser endomicroscopy in Zambian adults

BACKGROUND

Confocal laser endomicroscopy (CLE) may increase the detection of gastric premalignant lesions, and facilitate targeted biopsies for histology. The study aim was to analyse premalignant lesions in Zambian adults using CLE.

METHODS

Using CLE and histology we analysed the antral mucosa for gastric premalignant lesions in asymptomatic adults living with HIV and in HIV seronegative adults. Fasting gastric pH and the presence of Helicobacter pylori (H. pylori) were also evaluated.

RESULTS

We enrolled 84 HIV seropositive participants (median age 43 years; 55 (65%) female), of whom 32 (38%) were anti-retroviral therapy (ART)-naïve. Also enrolled were 22 HIV seronegative controls (median age 39 years, 12 (55%) females). Hypochlorhydria was found in 48 (57%) HIV positive and 8 (38%) HIV negative controls (P = 0.14). Detection of gastric intestinal metaplasia (GIM) was higher (P = 0.007) using CLE (49, 54%) than histology (9, 9%) and, using CLE, GIM was similar between HIV positive (41, 60%) and negative groups (8, 36%; P = 0.08). Gastric luminal fluorescein leakage was significantly associated with the presence of GIM [OR 8.2; 95% CI 2.5-31, P<0.001].

CONCLUSION

CLE is useful for the detection of GIM, and luminal fluorescein leakage may represent a novel CLE marker for GIM. GIM is common in Zambian adults, and is highly prevalent irrespective of HIV infection or use of ART.

VacA and CagA Status as Biomarker of Two Opposite End Outcomes of Helicobacter pylori Infection (Gastric Cancer and Duodenal Ulcer) in a Moroccan Population

Helicobacter pylori (H. pylori) infection induces inflammation of the gastric mucosa, which may progress to precancerous lesions leading to gastric cancer. Pathological determinism is associated to some virulence genes of the bacterium, notably the vacA and cagA genes. The present study aimed to determine the H. pylori genotypes distribution and their association with sex, age and gastric diseases in a Moroccan population. Gastric biopsy was taken from 1079 consenting patients. The specimens were processed by PCR to identify H. pylori and to determine the genotypic profile by PCR characterizing vacA s, vacA m and vacA i regions directly from biopsies H. pylori positives. VacA genotyping revealed the predominance of vacA m2 (53.2%), vacA s2 (52.9%) and vacA i2 (52%). The most virulent vacA alleles (s1, i1 and m1) are more predominant in men (47.3%, 41.9% and 46.1% respectively) than in women (38.3%, 33.3% and 37% respectively). However, the association between vacA genotypes and age did not reach a statistical significant value. Logistic regression analysis results show that vacA i1m1 and vacA i1m2 genotypes were strongly associated with the risk of GC, the Odds Ratio (95% confidence interval) was 29.73 [5.08-173.73] and 9.17 [2.06-40.82] respectively, while vacAs1/cagA+ seems to be a risk factor for DU since it is inversely associated with GC (OR was 0.13 [0.02-0.75]. The results of this study suggest that vacA i1 genotype independently to vacAm status may be of a clinical usefulness and will help to identify patients at a high risk of GC development.

Correlation of Helicobacter pylori genotypes with gastric histopathology in the central region of a South-European country

BACKGROUND

Outcome of Helicobacter pylori (H. pylori) infection results from interaction of multiple variables including host, environmental and bacterial-associated virulence factors.

AIM

This study aimed to investigate the correlation of cagA, cagE, vacA, iceA and babA2 genotypes with gastric histopathology and disease phenotype in the central region of a South-European country.

METHODS

This prospective study involved 148 infected patients (110 female; mean age 43.5 ± 13.4 years) submitted to endoscopy with corpus and antrum biopsies. H. pylori was cultured and DNA extracted from the isolates. Genotypes were determined by PCR. Histopathological features were graded according to the updated Sydney system and OLGA/OLGIM classification. Only patients with single H. pylori genotypes and complete histopathological results were included.

RESULTS

Antrum samples presented higher degrees of atrophy, intestinal metaplasia, chronic inflammation and neutrophil activity. Genotype distribution was as follows: cagA-31.8 %; cagE-45.9 %; vacA s1a-24.3 %; vacA s1b-19.6 %; vacA s1c-0.7 %; vacA s2-55.4 %; vacA m1-20.9 %; vacA m2-79.1 %; vacA s1m1-18.9 %; vacA s1m2-25.7 %; vacA s2m1-2 %; vacA s2m2-53.4 %; iceA1-33.8 %; iceA2-66.2 %; babA2-12.2 %. CagA genotype was significantly associated with higher degrees of intestinal metaplasia, neutrophil activity, chronic inflammation and OLGIM stages. BabA2 was linked with higher H. pylori density. Strains with vacA s1m1 or vacA s1m1 + cagA positive genotypes had a significant association with peptic ulcer and vacA s2m2 with iron-deficient anemia.

CONCLUSIONS

cagA, vacA s1m1 and babA2 genotypes are relatively rare in the central region of Portugal. cagA-positive strains are correlated with more severe histopathological modifications. This gene is commonly associated with vacA s1m1, and such isolates are frequently found in patients with peptic ulcer.

Helicobacter pylori: the balance between a role as colonizer and pathogen

The isolation of Helicobacter pylori from the human stomach produced significant changes in how gastroenterologists, immunologists, epidemiologists, pathologists and microbiologists have approached gastro-duodenal diseases in the last half of the XX century. However, research of this organism has progressed greatly in the first decade of this century, evidence suggest that H. pylori is associated with disease only in humans older than 40 years, while, the lack of H. pylori colonization is associated with the emergence of new diseases, particularly in younger individuals. These differing effects of H. pylori colonization have created two contrasting concepts: the 'bad' and the 'good' Helicobacter. Following from renewed interest in the normal human microbiome, we need to reconsider our definitions and perhaps recognize that H. pylori might be a normal member of the human gastric microbiome in ancient humans that gradually, as results of the improvement in our environment, is disappearing.