High Frequency of vacA s1m2 Genotypes Among Helicobacter pylori Isolates From Patients With Gastroduodenal Disorders in Kermanshah, Iran

In silico study revealed the inhibitory activity of selected phytomolecules of C. rotundus against VacA implicated in gastric ulcer

Gastric ulcer is associated with weakening of the mucous coating of the stomach and damages to the intestinal lining. It is caused by H. pylori assisted by enzymes including VacA, which necessitates the need for inhibitors of VacA. Bioactive compounds from Cyperus rotundus have been documented to have anti-inflammatory activities. However, the mechanism of action of the phytochemicals is not characterized. This research aimed to assess, in silico, the potential of selected bioactive compounds against VacA based on the binding to its active sites. VacA and bioactive compounds structures were obtained from protein database and PubChem webserver, respectively. All compounds, including 2 controls, omeprazole and cimetidine were docked against the protein using AutoDock Vina and screened based on the binding energy. The selected complexes were subjected to pharmacokinetics and toxicity screening. Finally, molecular dynamics simulation and MMPBSA were carried out on two best compounds. 17 compounds interacted with the active site of VacA with higher binding affinities, with 7 of them - aureusidine, catechin, chlorogenic acid, isorhamnetin, isovitexin, oreintin, and vitexin having the best behaviours based on ADMET and druglikeness screening. Molecular dynamics and MMPBSA experiments of two of the hits corroborated good stability and binding energy for Ellagic Acid and Scirpusin B (ΔG = -14.38 and -13.20 kcal mol-1, respectively). These phytochemicals showed good pharmacokinetic profiles with respect to the control drugs. This study revealed that the identified compounds of C. rotundus may serve as VacA inhibitors and may be potent candidates for novel drug formulations in gastric ulcer treatment.Communicated by Ramaswamy H. Sarma.

Is There a Real Relationship between the Presence of Helicobacter pylori in Dental Plaque and Gastric Infection? A Genotyping and Restriction Fragment Length Polymorphism Study on Patient Specimens with Dyspepsia in Southwest Iran

Background

The oral cavity can act as an extra gastric reservoir for H. pylori, and the presence of the bacteria in the oral cavity is associated with a higher risk of dental caries development. This study aimed to determine the genotype and evaluate the association between the presence of H. pylori in dental plaque and gastric biopsy specimens in dyspeptic patients in Ahvaz, Southwest Iran.

Methods

In this study, 106 patients with recruited dyspeptic complaints were selected, and from each patient, two gastric antral biopsy specimens and two dental plagues were examined. The presence of H. pylori was identified by the rapid urease test (RUT) and the amplification of ureAB and 16S rRNA genes. Also, to verify a hypothetical mouth-to-stomach infection route, the enzymatic digestions of three genes of cagA, vacA, and ureAB in H. pylori strains isolated from dental plaques and stomach samples were compared for each same case.

Results

H. pylori was found in the stomach of 52.8% (56/106) and the dental plaques of 17.9% (19/106) of the studied cases. On the other hand, H. pylori was recognized in the stomach of all 19 cases with oral colonization. Following a combination of restriction fragment lengths 21 polymorphism (RFLP) patterns of these three known genes on stomach and dental plague samples, 14 and 11 unique patterns were seen, respectively. However, for all H. pylori-positive cases (19), the comparison of RLFP patterns of these genes in dental plaque and gastric biopsy specimens was different for the same case.

Conclusions

In this study, it seems that there is no significant association between the presence of H. pylori in dental plaque and the stomach of the same case.

Impact of Helicobacter pylori virulence markers on clinical outcomes in adult populations

BACKGROUND

In recent years, associations between specific virulence markers of Helicobacter pylori (H. pylori) and gastrointestinal disorders have been suggested.

AIM

To investigate the presence of virulence factors including vacuolating cytotoxin A genotypes (s1m1, s1m2, s2m1, and s2m2), cytotoxin-associated gene A (CagA), and urease activity in H. pylori strains isolated from Arab and Jewish populations in northern Israel and to assess associations between these factors and patients’ demographics and clinical outcomes.

METHODS

Patients (n = 108) who underwent gastroscopy at the Baruch Padeh Medical Center, Poriya due to symptomatic gastroduodenal pathologies as part of H. pylori diagnosis were enrolled in the study. Gastric biopsy specimens were collected from the antrum of the stomach. Clinical condition was assessed by clinical pathology tests. Bacteria were isolated on modified BD Helicobacter Agar (BD Diagnostics, Sparks, MD, United States). Bacterial DNA was extracted, and PCR was performed to detect CagA and vacuolating cytotoxin A genes. Urease activity was assessed using a rapid urease test.

RESULTS

A significant correlation was found between disease severity and patient ethnicity (P = 0.002). A significant correlation was found between CagA presence and the s1m1 genotype (P = 0.02), which is considered the most virulent genotype. Further, a higher level of urease activity was associated with isolates originating from the Jewish population. Moreover, higher urease activity levels were measured among CagA-/s1m1 and CagA-/s2m2 isolates.

CONCLUSION

Our study highlights the importance of incorporating molecular methods for detection of virulence markers of H. pylori in order to tailor optimal treatments for each patient. Further investigation should be performed regarding associations between H. pylori virulence factors and ethnicity.

Clinical relevance of the cagA and vacA s1m1 status and antibiotic resistance in Helicobacter pylori: a systematic review and meta-analysis

BACKGROUND

The role of Helicobacter pylori (H. pylori) virulence factors of such as vacA s1m1 and cagA in designating clinical outcomes and eradication rate has been deeply challenged in the last decade. The goal of this analysis was to identify the potential relevance between cagA and vacA genotypes with reported antibiotic resistance observed in clinical H. pylori isolates.

METHODS

This literature search was conducted in databases such as Clarivate analytics, PubMed, Scopus, EMBASE, DOAJ, and Google Scholar by April 2022, regardless of language restrictions and publication date. Quality of the included studies was assessed by the Newcastle-Ottawa scale. Statistical analysis of retrieved studies was fulfilled using Comprehensive Meta-Analysis software version 2.2. Following quality appraisal of eligible studies, potential association between the status of cagA and vacA genes with resistance to clarithromycin, metronidazole, amoxicillin, tetracycline, and levofloxacin was measured using odds ratio with 95% confidence interval. We also used sensitivity analyses and meta-regression to eliminate the source of heterogeneity from the overall estimates. Publication bias was assessed using funnel plot, Egger's test, Begg's test with the trim and fill procedure to assess the presence and magnitude of publication bias in the included studies.

RESULTS

Our findings suggested that a significant relationship between cagA status ‎and increase resistance ‎to metronidazole (OR: 2.69; 95% CI: 1.24-5.83‎‏‎). In subgroup analysis, we ‎found that in the Western ‎population, infection with cagA-positive strains could be led to increase in ‎the resistance to ‎metronidazole (OR: 1.59; 95% CI: ‎0.78-3.21‎‏‎), ‎amoxicillin (OR: ‎19.68‎; 95% CI: 2.74-‎‎141.18), ‎and ‎levofloxacin (OR: ‎11.33; 95% CI: ‎1.39-‎‎91.85). After implementation of trim and fill method, the adjusted OR was not significantly differed from original estimates which in turn represented our subgroup analysis was statistically robust. On the other hand, vacA ‎genotypes usually ‎reduce the antibiotic resistance of this bacterium, so that vacA s1m1 significantly reduces the ‎resistance to ‎metronidazole (OR: 0.41; 95% CI: 0.20-0.86‎‏‎). Surprisingly, resistance of vacA s2m2 strains to antibiotics was low, the reason may be due ‎to the non-inflammatory properties of strains containing vacA s2m2. The meta-regression and sensitivity analyses successfully reduced the effect of heterogeneity from the overall estimates. In addition, although the pooled OR is reduced after trim and fill adjustment but results do not change the conclusion regarding vacA genotypes and antibiotic resistance.

CONCLUSIONS

According to our findings, it was clearly demonstrated that cagA-positive strains are resistance to metronidazole, especially in Western countries. In Western countries, vacA s1m1 increases resistance to amoxicillin and levofloxacin. Based on the present findings, the vacA s1m1 genotype significantly increases resistance to metronidazole, while the vacA s1m2 decreases resistance to clarithromycin and metronidazole. Resistance to antibiotics in less virulent (vacA s2m2) strains is statistically significant lower than others.

Evaluation of antibiotic resistance of Helicobacter pylori bacteria obtained from gastric biopsy samples: A cohort study

Objective

Helicobacter pylori infection is associated with a wide range of gastrointestinal diseases and is very common in developing countries. Overuse and self-prescribed antibiotics have led to antibiotic resistance and failure of complete eradication of the bacterium. The aim of this study is to evaluate the antibiotic resistance of h. pylori from samples obtained from gastric biopsy.

Methods

In this descriptive-analytical study was performed on 205 patients’ samples positive for h. pylori infection. Following h. pylori testing, the sample were culture with different antibiotics to obtain data regarding the resistance. Demographic information of the patients such as age, sex, employment status, area of residence and patient-related factors such as reason for referral, and previous history of treatment were obtained and evaluated for the correlation with antibiotic resistance.

Results

In this study, the mean age of the subjects was 42.32 ± 16.65 years. The most common reason for referral of patients in the present study was epigastric pain in 49.3% (101 patients). Antibiotic resistance to amoxicillin was 46.8%, tetracycline was 41%, metronidazole was 33.2%, clarithromycin was 70.7%. levofloxacin was 36.1% and bismuth was 19.5%. Sex, age, type of living (rural or urban), employment, reason for referral and history of treatment was not associated with any antibiotic resistance, p > 0.05.

Conclusion

Our study showed that clarithromycin resistance is the most common in our population followed by amoxicillin and tetracycline. Excessive use of these antibiotics and self-prescription should be analyzed in future studies and public-awareness programs might be required.

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H.pylori infection is associated with a wide range of gastrointestinal diseases.

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Self-prescribed antibiotics have led to antibiotic resistance and failure of complete eradication.

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Clarithromycin resistance is the most common in our population followed by amoxicillin and tetracycline.

Evaluation of Helicobacter pylori Genotypes in Obese Patients with Gastric Ulcer, Duodenal Ulcer, and Gastric Cancer: An Observational Study

INTRODUCTION

Obesity is a well-known risk factor for a variety of gastrointestinal disorders (GID). Helicobacter pylori is associated with different GID, such as gastric cancer and chronic gastritis. In this study, we investigated the prevalence of dominant genotypes in H. pylori isolated from obese patients diagnosed with gastric ulcer, duodenal ulcer, and gastric cancer.

METHODS

A total of 222 H. pylori-positive samples were collected from patients with obesity. GID and gastric cancer were identified by endoscopy and histopathology, respectively. Three biopsy specimens from the gastric antrum were obtained from each patient for culture tests, histological examination, and identification of vacuolating cytotoxin A (vacA) (vacA s1, vacA s2, vacA m1, vacA m2, vacA s1m1 vacA s1m2, vacA s2m1, and vacA s2m2), cagA, cagE, iceA1, oipA, dupA, and babA2 using polymerase chain reaction.

RESULTS

vacA, cagE, cagA, iceA1, oipA, dupA, and babA2 genes were detected in 222 (100%), 171 (77%), 161 (72.5%), 77 (34.6%), 77 (34.6%), 137 (61%), and 69 (31%) patients with obesity, respectively. Our findings revealed that vacA, iceA1, oipA, and babA2 were significantly associated with a higher risk of GID, while cagE, cagA, and dupA indicated no correlation with the development of GID. Also, in the combination of s- and m-region genotypes, s1m2 (79%) was the most frequently identified genotype in patients with obesity. A significant association was also found between cagA and the presence of vacA genotypes (except for vacA m1 and babA2).

CONCLUSIONS

This study indicated the high prevalence of different virulence genes in H. pylori isolated from obese patients and supported the significant role of H. pylori in the development of GID.

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.

Association of Helicobacter pylori vacA genotypes and peptic ulcer in Iranian population: a systematic review and meta-analysis

BACKGROUND

Helicobacter pylori is accounted as the most etiologic agent for digestive disorders, in particular, the most important of them i.e. peptic ulcer and gastric cancer. In the recent years, association of vacA genotypes and gastrointestinal disorders has attracted a lot of attention. In present study, we assessed the correlation between vacA genotypes (s1, s2, m1, m2, s1m1, s1m2, s2m1 and s2m2) and development to peptic ulcer in Iranian population.

METHODS

In our study, first, 24 original articles containing of information of 3328 patients were evaluated. Statistical analysis was done by Comprehensive Meta-Analysis version 2.0 software (Biostat, Englewood, NJ, USA). In this regards, we used from fixed-effects model for analysis of data with low heterogeneity, while for analysis of data with high heterogeneity (I2 statistic index > 25%, Cochrane Q statistic p value < 0.05), random-effects model was used.

RESULTS

Abundance of each of s1, s2, m1, m2, s1m1, s1m2, s2m1, and s2m2 was estimated 36.24, 28.32, 42.90 29.86, 27.88, 32.34, 15.70, and 25.94%, respectively. According to the results, the m1, s1, and s1m2 genotypes were among the most prevalent genotypes among the Iranian patients, whereas, s2m1 genotype had the lowest frequency.

CONCLUSIONS

Overall, 24 articles (total participants = 3328) were included in this comprehensive analysis. H. pylori infection rate were 90.26% in these cases, so that 33.65% of whom had peptic ulcer. Moreover, the abundance of each vacA genotypes including s1, s2, m1, m2, s1m1, s1m2, s2m1, and s2m2 was estimated as 36.24, 28.32, 42.90 29.86, 27.88, 32.34, 15.70, and 25.94% respectively. We demonstrated that there is a significant relationship between infection of stomach with m1, s1m1, and s2m1 genotypes and development to peptic ulcer disease.

Rapid and accurate detection of Helicobacter pylori from biopsy specimens using loop-mediated isothermal amplification

Loop-mediated isothermal amplification (LAMP) is a promising nucleic acid-based assay for quick, accurate and cost-effective diagnosis of many infectious agents. The purpose of this study was to assess the diagnostic value of LAMP for rapid and accurate detection of Helicobacter pylori in biopsy specimens. Patients suffering from one or several gastroduodenal disorders were enrolled in the study. Specificity, sensitivity, and the positive and negative predictive values of LAMP were compared with the gold standard result, which was the assembled result of culture, rapid urease test and polymerase chain reaction. Sensitivity, specificity, and the positive and negative predictive values of LAMP in comparison with the gold standard result were 100%, 30.76%, and 87.67% and 100% respectively [%95 CI]. As the diagnostic value of LAMP is favourable, the method is an optimum technique for diagnosis the presence of H. pylori in different clinical and environmental samples.

Detection of Helicobacter pylori and its virulence genes (cagA, dupA, and vacA) among patients with gastroduodenal diseases in Chris Hani Baragwanath Academic Hospital, South Africa

BACKGROUND

The global prevalence of H. pylori approaches 50%, with prevalence rates between 20 and 40% in developed countries and up to 90% in Africa and other developing nations of the world. Development of H. pylori-associated diseases is determined by a number of virulence factors. This study aimed at determining the prevalence of H. pylori infections and virulence genes (cagA, dupA, and vacA); the relationship between virulence factors and gastroduodenal diseases among patients.

METHODS

Gastric biopsies were obtained from patients and cultured, DNA was extracted from cultured isolates and biopsies for PCR assay after which samples were investigated using standard laboratory procedures. Data of associated risk factors were obtained with the aid of questionnaires.

RESULTS

Of the 444 participants, H. pylori was detected in 115 (25.9%) from culture analysis and 217 (48.9%) by direct PCR method. Ninety-eight (85.2%) of the culture-positive patients were also detected by PCR giving an overall prevalence of 52.7% (234/444). The highest number of H. pylori isolates 76.9% (180/234) was obtained from patients suffering from pangastritis. The CagA virulence gene was found in 62% (145/234), dupA in 53.4% (125/234) and vacA in 90.6% (212/234). VacA genotype s1 m1 was the most prevalent [56.4% (132)] followed by s2 m2 [11.5% (27)], s2 m1 [10.3% (24)] and [s1 m2 9.4% (22)]. There was a significant association observed in vacA s1 and peptic ulcer disease, as well as vacA s1/m2 and gastric erosion (P < 0.05).

CONCLUSION

The study revealed a significant association between virulence genes and the development of certain forms of gastric infections while the variations in H. pylori detection and the associated risk factors investigated in the study were not significantly related.

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.

Prevalence and factors associated with H. pylori infection in Saudi patients with dyspepsia

Background

Helicobacter pylori (H. pylori) is a major cause of peptic ulcer disease (PUD) and chronic active gastritis that may progress to gastric cancer. Globally, it has been estimated that 50% or more of the world’s population is infected by H. pylori, making it the most widespread infection across the globe.

Objectives

To determine the prevalence of H. pylori infection and to identify factors associated with H. pylori infection in Saudi patients presenting with dyspepsia.

Methods

In this prospective cross-sectional study, a total of 404 gastric biopsies were endoscopically obtained from 404 patients with dyspepsia from September 2014 to April 2016 (Jazan Province, Saudi Arabia). The specimens were analyzed using the real-time polymerase chain reaction (PCR). The data was examined using descriptive statistics as well as determining the prevalence, and employing Chi square and Fisher exact test. A p-value of ≤0.05 was considered statistically significant in examining the research hypotheses.

Results

The overall prevalence of H. pylori in Jazan Province was 46.5% (95% CI: 41.7–51.4) and the prevalence was lower among those > 55 years old. Prevalence was higher among urban (50.0%; 95% CI: 43.1–56.8) versus rural (42.1%; 95% CI: 35.1–49.3), but with no significant difference. Prevalence did not show significant difference among different Body Mass Index (BMI) categories, ranging from 40.2% to 47.7%. The prevalence of H. pylori in females was 47.1% (95% CI: 40.4–53.9) versus 45.6% (95% CI: 38.7–52.6) in males. Histopathology findings were associated with H. pylori infection with prevalence of 58.1% among patients with chronic active gastritis, compared to 24.1% and 34.8% among mild and chronic gastritis, respectively.

Conclusion

Our results indicate that there is a high prevalence of H. pylori among Saudi patients with dyspepsia. Prevalence of H. pylori was high in ages below 55 years. Chronic active gastritis was significantly associated with H. pylori infection. In depth studies are needed to determine associated factors with of H pylori infection in the region

Can bacterial virulence factors predict antibiotic resistant Helicobacter pylori infection?

AIM

To evaluate the association between virulence factor status and antibiotic resistance in Helicobacter pylori (H. pylori)-infected patients in Ireland.

METHODS

DNA was extracted from antral and corpus biopsies obtained from 165 H. pylori-infected patients. Genotyping for clarithromycin and fluoroquinolone-mediating mutations was performed using the Genotype HelicoDR assay. cagA and vacA genotypes were investigated using PCR.

RESULTS

Primary, secondary and overall resistance rates for clarithromycin were 50.5% (n = 53/105), 78.3% (n = 47/60) and 60.6% (n = 100/165), respectively. Primary, secondary and overall resistance rates for fluoroquinolones were 15.2% (n = 16/105) and 28.3% (n = 17/60) and 20% (n = 33/165), respectively. Resistance to both antibiotics was 12.4% (n = 13/105) in treatment-naïve patients, 25% (n = 15/60) in those previously treated and 17% (n = 28/165) overall. A cagA-positive genotype was detected in 22.4% (n = 37/165) of patient samples. The dominant vacA genotype was S1/M2 at 44.8% (n = 74/165), followed by S2/M2 at 26.7% (n = 44/165), S1/M1 at 23.6% (n = 39/165) and S2/M1 at 4.8% (n = 8/165). Primary clarithromycin resistance was significantly lower in cagA-positive strains than in cagA-negative strains [32% (n = 8/25) vs 56.3% (n = 45/80) P = 0.03]. Similarly, in patients infected with more virulent H. pylori strains bearing the vacA s1 genotype, primary clarithromycin resistance was significantly lower than in those infected with less virulent strains bearing the vacA s2 genotype, [41% (n = 32/78) vs 77.8% (n = 21/27) P = 0.0001]. No statistically significant association was found between primary fluoroquinolone resistance and virulence factor status.

CONCLUSION

Genotypic H. pylori clarithromycin resistance is high and cagA-negative strains are dominant in our population. Less virulent (cagA-negative and vacA S2-containing) strains of H. pylori are associated with primary clarithromycin resistance.

Determination of Helicobacter pylori virulence-associated genes in duodenal ulcer and gastric biopsies

Background:Helicobacter pylori (H. pylori or Hp) has been strongly associated with the peptic ulcer diseases, chronic gastritis, ulcers, and gastric cancer. Genes associated with pathogenicity have been designated for H. pylori, and some of them appear to be related to more severe clinical consequences of the infection. The present study was conducted to determine cagA, vacA, cagE, iceA1, oipA, and iceA2 genes in H. pylori strains isolated from gastroduodenal patients, who referred to Shariati hospital in Tehran, Iran. Methods: Gastric biopsy specimens were collected during endoscopy from patients, who referred to the Shariati hospital in Tehran, Iran during January and November 2015. After isolation of H. pylori from the biopsy culture, genomic DNA was extracted and subsequently used to identify H. pylori and virulence genes using specific primers. Results: The isolation rate of H. pylori strains was 65.7% (169/257). The frequency of cagA, vacA, cagE, iceA1, oipA, and iceA2 was 143 (% 84.6), 169 (100%), 131 (77.5%), 97 (57.3%), 89 (52.6%), and 72 (42.6%), respectively. Conclusion: In this study, a significant difference was observed between investigated genes and strains isolated from PUD and GC patients (p<0.05).

Correlation between virulence markers of Helicobacter pylori in the oral cavity and gastric biopsies

BACKGROUND:

The clinical outcome of Helicobacter pylori infection has been associated with virulence factors. The presence of these factors is useful as molecular markers in the identification of the high risk for developing severe gastric pathologies.

OBJECTIVE:

To correlate the presence of virulence markers cagA and bab2A of H. pylori in oral and gastric biopsy samples.

METHODS:

An observational, prospective, descriptive, and cross-sectional study was carried out between September 2011 and September 2012. Patients suffering dyspepsia with indication for upper gastrointestinal video endoscopy who attended the Gastroenterology Service of the Hospital Dr. Julio C. Perrando were included. Epidemiological investigation was completed. To detect the bacteria and their virulence genes, samples of saliva, dental plaque and gastric biopsy were taken and processed by PCR.

RESULTS:

Sixty-one patients were selected for this study (30 women and 31 men). H. pylori was detected in 31 gastric biopsies and 31 oral samples. Significant difference between oral and gastric samples was found in cagA genotype. Agreement between oral and gastric genotypes was found in 38.7% of samples from the same patient.

CONCLUSION:

This study is the first in provide information about the genotypes of the Argentinean Northeast H. pylori strains. Despite the high prevalence of H. pylori infection, the most of patients had less virulent genotypes in oral cavity and gastric tissue. The cagA / babA2 combination was not frequent in the samples studied. There was not a statistical correlation between the virulence genes and gastroduodenal or oral diseases. Although in some patients the same genotype was found both in oral and gastric samples, it cannot be ensure that they corresponding to the same strain because a DNA sequencing was not performed.

Epidemiology of Helicobacter pylori infection

This review of recent publications related to the epidemiology of Helicobacter pylori highlights the origin of the infection, its changing prevalence, transmission, and outcome. A number of studies have addressed the ancestor roots of the bacteria, and the first genomewide analysis of bacterial strains suggests that its coexistence with humans is more ancient than previously thought. As opposed to the generally declining prevalence of H. pylori (including China and Japan), in Sweden, the prevalence of atrophic gastritis in the young population has risen. The prevalence of the infection remains high in the indigenous populations of the Arctic regions, and reinfection rates are high. A high prevalence is permanently found in the Siberian regions of Russia as well. Several studies, some of which used multiplex serology, addressed prevalence of and risks associated with various H. pylori serotypes, thereby enabling more precise risk assessment. Transmission of H. pylori was discussed, specifically fecal-oral transmission and the use of well-water and other unpurified water. Finally, the long-term course of H. pylori infection was considered, with an estimated 89% of noncardia gastric cancer cases being attributable to the infection.