Detection of Helicobacter pylori in Gastric Aspirates Using a Monoclonal Antibody-Based Test

Background/Aims

The objective of this study was to evaluate a monoclonal antibody-based test to detect Helicobacter pylori-specific antigen in gastric aspirates from humans.

Methods

Sixty-one volunteers were enrolled in the study. All of the subjects underwent a ¹³C-urea breath test (UBT) before esophagogastroduodenoscopy. Gastric aspirates were analyzed for pH and ammonia and used for polymerase chain reaction (PCR), culture, and monoclonal antibody-based detection of H. pylori. Multiple biopsies of the gastric antrum and body were obtained for a rapid urease test (RUT) and histological evaluation.

Results

Thirty-six subjects were H. pylori-positive and 25 were H. pylori-negative according to the UBT results. Compared with the H. pylori-negative subjects, H. pylori-positive subjects had a higher pH (4.77±1.77 vs 3.49±1.30, p<0.05) and ammonia level (1,130.9±767.4 vs 184.2±126.3, p<0.0001). The sensitivities and specificities of the PCR test, RUT, culture test, and monoclonal antibody-based test were 100% and 72%, 89% and 100%, 47% and 100%, and 78% and 100%, respectively.

Conclusions

The monoclonal antibody-based test for diagnosing H. pylori infection in gastric aspirates has increased sensitivity compared with the culture test and specificity as high as that of the RUT. The test may be useful as an additive test for examining gastric aspirates.     

Treatment Outcome for Gastric Mucosa-Associated Lymphoid Tissue Lymphoma according to Helicobacter pylori Infection Status: A Single-Center Experience

Background/Aims

Helicobacter pylori eradication therapy has been used as a first-line treatment for H. pylori-positive gastric mucosa-associated lymphoid tissue (MALT) lymphoma. However, the management strategy for H. pylori-negative MALT lymphoma remains controversial. Therefore, the aim of this study was to examine the success rate of each treatment option for H. pylori-positive and H. pylori-negative gastric MALT lymphomas.

Methods

In total, 57 patients with gastric MALT lymphoma diagnosed between December 2000 and June 2012 were enrolled in the study. The treatment responses were compared between H. pylori-positive and H. pylori-negative gastric MALT lymphomas.

Results

Of the 57 patients, 43 (75%) had H. pylori infection. Forty-eight patients received H. pylori eradication as a first-line treatment, and complete remission was achieved in 31 of the 39 patients (80%) with H. pylori-positive MALT lymphoma and in five (56%) of the nine patients with H. pylori-negative MALT lymphoma; no significant difference was observed between the groups (p=0.135). The other treatment modalities, including radiation therapy, chemotherapy, and surgery, were effective irrespective of H. pylori infection status, with no significant difference in the treatment response between H. pylori-positive and H. pylori-negative MALT lymphomas.

Conclusions

H. pylori eradication therapy may be considered as a first-line treatment regardless of H. pylori infection status.     

The Effects of Broccoli Sprout Extract Containing Sulforaphane on Lipid Peroxidation and Helicobacter pylori Infection in the Gastric Mucosa

Background/Aims

The aims of this study were to investigate whether a broccoli sprout extract containing sulforaphane (BSES) inhibited the Helicobacter pylori infection density and exerted an antioxidative effect on gastric mucosal damage.

Methods

The enrolled subjects were randomized in a double-blinded manner into three groups. Finally, 33 H. pylori (+) BSES treatment subjects (group A), 28 H. pylori (+) placebo subjects (group B), and 28 H. pylori (−) BSES treatment subjects (group C) were studied. H. pylori infection density was indirectly quantified by a ¹³C-urea breath test (UBT), and the ammonia concentration in gastric juice aspirates was measured through gastroscopic examination. Malondialdehyde (MDA), an oxidative damage biomarker, and reduced glutathione (GSH), an antioxidant biomarker, were measured in the gastric mucosa by an enzyme-linked immunosorbent assay.

Results

BSES treatment did not significantly affect the UBT values or ammonia concentration in group A (p=0.634 and p=0.505, respectively). BSES treatment did significantly reduce mucosal MDA concentrations in group A (p<0.05) and group C (p<0.001), whereas the gastric mucosal GSH concentrations did not differ before and after treatment in any of the groups.

Conclusions

BSES did not inhibit the H. pylori infection density. However, BSES prevented lipid peroxidation in the gastric mucosa and may play a cytoprotective role in H. pylori-induced gastritis.     

Relationship between the Extent of DNA Damage and Gastritis in Normal and Helicobacter pylori-Infected Patients

Background/Aims

The role of Helicobacter pylori in gastric carcinogenesis is unclear, but H. pylori infection is thought to predispose carriers to gastric cancer. The aim of this study was to investigate the relationship between the extent of DNA damage in normal gastric epithelial cells and H. pylori-positive and -negative gastritis according to histological diagnosis. We also compared the percentage of cometed cells on the surface of the gastric epithelial cells to the percentage beneath the gastric mucosal cells using serial incubations times.

Methods

The comet assay is a rapid, efficient and reproducible measure of DNA damage in single cell and it was used in this study. DNA damage was evaluated in 52 cases using alkaline single cell gel electrophoresis (comet assay). Comparisons were made between 19 normal individuals, 19 patients with H. pylori-positive and -negative gastritis and 14 mixed cases with different histology gradings to determine if there was a relationship between histological diagnosis and DNA damage (comet percentage).

Results

The comet percentages in specimens from cases with normal histology were significantly higher than the comet percentages in specimens from cases with H. pylori-positive gastritis. In addition, there was a significant increase in the percentage of cometed cells on the surface of gastric epithelial cells in both normal and H. pylori-infected cells compared to the subsequent gastric cell layers of the same specimen.

Conclusions

A relationship between the comet percentage and the histological diagnosis was observed.     

High Recurrence Rate of Idiopathic Peptic Ulcers in Long-Term Follow-up

Background/Aims

Our aim was to compare the long-term clinical outcomes of idiopathic peptic ulcer disease (IPUD) with those of Helicobacter pylori-positive and nonsteroidal anti-inflammatory drug (NSAID)-induced peptic ulcer disease (PUD).

Methods

Patients with endoscopically diagnosed PUD were retrospectively reviewed. According to their H. pylori-infection status and history of NSAIDs use, patients were categorized into three groups: H. pylori-positive PUD, NSAID-induced PUD, and IPUD. Clinical outcomes were analyzed, and the recurrence rate of PUD was compared among the three groups.

Results

A total of 238 patients were enrolled. Those with IPUD, NSAID-induced PUD, and H. pylori-positive PUD comprised of 56, 60, and 122 patients, respectively. The 5-year cumulative incidences of recurrent ulcers were 24.3% (95% confidence interval [CI], 11.6% to 37.0%) in IPUD, 10.9% (95% CI, 2.6% to 19.2%) in NSAID-induced PUD, and 3.8% (95% CI, 0.1% to 7.5%) in H. pylori-positive PUD (IPUD vs NSAID-induced PUD/H. pylori-positive PUD, p=0.43/p<0.001 by log-rank test). In the Cox-proportional hazards model, only IPUD remained as an independent risk factor associated with recurrent ulcers (hazard ratio, 5.97; 95% CI, 1.94 to 18.34; p=0.002).

Conclusions

IPUD exhibited a higher recurrence rate than H. pylori-positive and NSAID-induced PUD in long-term follow-up and was an independent risk factor for ulcer recurrence.     

Association between Helicobacter pylori Seropositivity and the Coronary Artery Calcium Score in a Screening Population

Background/Aims

Helicobacter pylori causes numerous extragastric manifestations, including coronary heart disease. The coronary artery calcification (CAC) score, measured using computed tomography (CT) has been used as a screening test for coronary atherosclerosis. This study investigated the association between H. pylori seropositivity and CAC scores in a screening population.

Methods

Patients who underwent a health checkup between October 2003 and July 2007 and who did not have a history of ischemic heart disease were enrolled in the study. Subjects were screened with a multidetector CT scan to determine the CAC score and for anti-H. pylori antibody immunoglobulin G; traditional risks for coronary heart disease were evaluated using a structured questionnaire, anthropometric measurements, and laboratory tests.

Results

Of the 2,029 subjects enrolled (1,295 males), 1,214 (59.8%) subjects were H. pylori positive and 815 were H. pylori negative. There were no significant differences in the baseline characteristics of the seropositive and seronegative patients. When the CAC presence or absence scores were considered, multivariate analysis revealed that H. pylori seropositivity was statistically associated with the presence of CAC and that this association was stronger in the mild CAC score category.

Conclusions

H. pylori seropositive patients are at a higher risk for coronary atherosclerosis regardless of traditional cardiovascular risk factors. This association is particularly applicable for early coronary atherosclerosis.     

Helicobacter pylori in Thai patients with cholangiocarcinoma and its association with biliary inflammation and proliferation

Objectives

To investigate whether Helicobacter spp. infection and the cagA of H. pylori are associated with hepatobiliary pathology, specifically biliary inflammation, cell proliferation and cholangiocarcinoma (CCA).

Methods

Helicobacter species including H. pylori, H. bilis and H. hepaticus were detected in the specimens using the polymerase chain reaction (PCR). Biliary inflammation of the liver and gallbladders was semi-quantitatively graded on hematoxylin and eosin (H&E)-stained slides. Biliary proliferation was evaluated by immunohistochemistry using the Ki-67-labelling index.

Results

Helicobacter pylori was found in 66.7%, 41.5% and 25.0% of the patients in the CCA, cholelithiasis and control groups (P < 0.05), respectively. By comparison, H. bilis was found in 14.9% and 9.4% of the patients with CCA and cholelithiasis, respectively (P > 0.05), and was absent in the control group. The cagA gene of H. pylori was detected in 36.2% and 9.1% of the patients with CCA and cholelithiasis, respectively (P < 0.05). Among patients with CCA, cell inflammation and proliferation in the liver and gallbladder were significantly higher among those DNA H. pylori positive than negative.

Conclusions

The present findings suggest that H. pylori, especially the cagA-positive strains, may be involved in the pathogenesis of hepatobiliary diseases, especially CCA through enhanced biliary cell inflammation and proliferation.     

An Inverse Relationship between the Expression of the Gastric Tumor Suppressor RUNX3 and Infection with Helicobacter pylori in Gastric Epithelial Dysplasia

Background/Aims

This study was performed to determine the association between RUNX3 expression and Helicobacter pylori infection in premalignant gastric lesions.

Methods

We examined 107 patients with gastric epithelial dysplasia who had undergone endoscopic mucosal resection or submucosal dissection. All tissue samples were evaluated by RUNX3 staining and subclassified by immunophenotype. H. pylori infection in dysplastic lesions and the normal surrounding tissue was examined by silver staining, and cagA status was assessed by polymerase chain reaction.

Results

The loss of RUNX3 expression was observed in 62 cases (57.9%), and an association with H. pylori infection was found in 54 cases (50.5%). The infection rate with the cagA-positive H. pylori strain was 63.0%. In RUNX3-negative lesions, the rate of H. pylori infection (p=0.03) and the frequency of category 4 lesions (according to the revised Vienna classification) were high (p=0.02). In addition, the gastric mucin phenotype was predominant. In RUNX3-negative category 4 lesions, the rate of cagA-positive H. pylori infection rate was high but not significantly increased (p=0.08).

Conclusions

Infection with H. pylori is associated with inactivation of RUNX3 in early gastric carcinogenesis. This mechanism was prominent in gastric cancer with a gastric mucin phenotype.     

Effect of Helicobacter pylori Eradication on the Development of Reflux Esophagitis and Gastroesophageal Reflux Symptoms: A Nationwide Multi-Center Prospective Study

Background/Aims

A two-year, prospective, nationwide multicenter study was undertaken to evaluate the effect of Helicobacter pylori eradication on the development of reflux esophagitis (RE) and gastroesophageal reflux disease (GERD) symptoms in the Korean population.

Methods

In total, 1,489 subjects without RE were enrolled at the outpatient clinics of 12 tertiary hospitals nationwide, and 452 subjects underwent follow-up (F/U) for 2 years to evaluate the development of RE and GERD symptoms.

Results

RE was found in 33 subjects (7.3% of 452 subjects) and 14 subjects (7.3% of 192 subjects) during the first and second year of F/U, respectively. H. pylori status was not associated with the development of RE. RE was found in six (9.0%) of 67 H. pylori-negative patients, in 26 (11.2%) of 233 eradicated subjects and in eight (7.0%) of 114 noneradicated subjects (p=0.532). Multivariate analysis showed that age ≥60 years (odds ratio [OR], 7.11; 95% confidence interval [CI], 1.92 to 26.41), alcohol consumption (OR, 4.43; 95% CI, 1.03 to 19.19) and F/U cholesterol levels ≥200 mg/dL (OR, 5.03; 95% CI, 1.32 to 19.17) were significant risk factors for the development of RE. There was no significant difference in the development of GERD symptoms or weight according to H. pylori status during the 2-year F/U.

Conclusions

Eradication of H. pylori did not affect the development of reflux esophagitis or GERD symptoms among patients in outpatient gastroenterology clinics in South Korea.     

Seroprevalence of Helicobacter pylori Infection in Korean Health Personnel

Background/Aims

The aims of this study were to evaluate whether doctors and nurses in a single hospital were at an increased risk of acquiring Helicobacter pylori infection in 2011 and to identify risk factors for H. pylori seroprevalence.

Methods

Nurses (n=362), doctors (n=110), health personnel without patient contact (medical control, n=179), and nonhospital controls (n=359) responded to a questionnaire during a health check-up, which included questions on socioeconomic status, education level, working years, and occupation in 2011. The prevalence of H. pylori was measured by serology.

Results

The seroprevalence rate was 29.8% (nurses), 34.5% (doctors), 30.7% (medical control), and 52.9% (nonhospital control). Among younger subjects (<40 years of age), the nonhospital control had a higher seropositivity rate (48.1%) than nurses (29.2%), doctors (29.8%), and the medical control (24.8%), which was not observable in subjects ≥40 years of age. The risk factors for H. pylori seroprevalence were not different for health and nonhealth personnel. A multivariate analysis indicated that seropositivity significantly increased with age, the province of residence, and a gastroscopic finding of a peptic ulcer.

Conclusions

The medical occupation was not associated with H. pylori infection. The seroprevalence of H. pylori in one hospital in 2011 was found to be 38.7%, most likely due to the improvement in socioeconomic status and hospital hygiene policy in Korea.     

Gastric biopsies: The gap between evidence-based medicine and daily practice in the management of gastric Helicobacter pylori infection

BACKGROUND:

Many consider histology to be the gold standard for Helicobacter pylori detection. Because the number and distribution of H pylori organisms vary, particularly in patients taking proton pump inhibitors (PPIs), the American Gastroenterological Association recommends discontinuing PPIs two weeks before endoscopy, and taking biopsies from both the body and antrum.

OBJECTIVE:

To assess the influence of clinical practice on the histopathological detection of H pylori infection.

METHODS:

Electronic patient records were evaluated for the sites of gastric sampling and PPI use at endoscopy. One hundred fifty cases with biopsies taken from both antrum and body were randomly selected for pathological re-review with special stains. The gastric regions sampled, H pylori distribution and influence of clinical factors on pathological interpretation were assessed.

RESULTS:

Between 2005 and 2010, 10,268 biopsies were taken to detect H pylori. Only one region was sampled in 60% of patients (antrum 47%, body 13%). Re-review of biopsies taken from both antrum and body indicated that the correct regions were sampled in only 85 (57%) patients. Of these, 54 were H pylori positive and 96 were H pylori negative. H pylori was present in the antrum in only 15% of the patients and body only in 21%. Of 96 H pylori-negative patients, two were reinterpreted as positive. Forty-seven per cent of patients were taking PPIs at endoscopy, contributing to both false-negative and false-positive diagnoses.

CONCLUSION:

Despite national and international guidelines for managing H pylori infection, the American Gastroenterological Association guidelines are infrequently adhered to, with PPIs frequently contributing to false diagnosis; sampling one region only increases the likelihood of missing active infection by at least 15%.     

Helicobacter pylori Infection Enhances Gastric Mucosal Inflammation in Individuals Carrying the 260-T Allele of the CD14 Gene

Background/Aims

We aim to evaluate the association between promoter polymorphism of the clusters of differentiation 14 (CD14) gene and Helicobacter pylori-induced gastric mucosal inflammation in a healthy Korean population.

Methods

The study population consisted of 267 healthy subjects who visited our hospital for free nationwide gastric cancer screening. Promoter polymorphism at -260 C/T of the CD14 gene was determined by polymerase chain reaction and restriction fragment length polymorphism analysis. The severity of gastric mucosal inflammation was estimated by a gastritis score based on the sum of the values of the grade and activity of the gastritis. Expression of soluble CD14 (sCD14) was assessed by quantitative sandwich ELISA.

Results

CD14 polymorphism was not associated with H. pylori infection. There were no significant differences in gastritis scores among the genotype subgroups, but subjects carrying the CD14 -260 CT/TT genotype had significantly higher sCD14 levels than those carrying the CC genotype. Subjects with the 260-T allele of the CD14 gene and H. pylori infection had significantly higher sCD14 levels than those with the same genotype but without infection.

Conclusions

In individuals with the T allele at the -260 site of the promoter region of the CD14 gene, H. pylori infection accentuates gastric mucosal inflammation.     

Role of F-FDG PET Scans in Patients with Helicobacter pylori-Infected Gastric Low-Grade MALT Lymphoma

Background/Aims

Endoscopic ultrasound (EUS) plays a crucial role in the assessment and treatment of low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma; however, interobserver variation, inadequate accuracy in judging the depth of tumor invasion, and histological heterogeneity of the tumor can limit its role. Thus, we have assessed the role of ¹⁸F-FDG PET scans in the management of Helicobacter pylori-infected gastric MALT lymphoma.

Methods

Eighteen patients with H. pylori-infected low-grade gastric MALT lymphoma underwent an ¹⁸F-FDG PET scan prior to receiving H. pylori eradication therapy. We analyzed these patients'' clinicopathologic data and measured the baseline and change in the metabolic activity of the tumor using standardized uptake values (SUVs).

Results

Two patients failed to achieve complete remission of the low-grade gastric MALT lymphoma after successful H. pylori eradication. The baseline SUVs were significantly higher in these patients compared to successfully treated patients, 13.35±0.07 vs 2.98±0.93, respectively (n=2 vs n=16, p<0.001). The reduction in the SUV was significantly greater in the complete remission patients compared to treatment failure patients (p=0.018).

Conclusions

A high SUV at baseline ¹⁸F-FDG PET and a lower reduction in the SUV within 3 months after eradication therapy are associated with treatment failure in H. pylori-positive low-grade gastric MALT lymphoma patients undergoing eradication treatment.     

Is the presence of Helicobacter pylori in the dental plaque of patients with chronic periodontitis a risk factor for gastric infection?

BACKGROUND

Helicobacter pylori is considered to be a pathogen responsible for gastritis and peptic ulcers, and a risk factor for gastric cancer. A periodontal pocket in the teeth of individuals with chronic periodontitis may function as a reservoir for H pylori.

OBJECTIVE:

The present study was undertaken to evaluate whether the presence of H pylori in the dental plaque of patients with and without periodontitis correlates with gastric involvement.

METHODS:

A total of 101 patients with dyspepsia were included in the present study. Subjects were divided into periodontitis and non-periodontitis groups. For the detection of H pylori in dental plaque, samples were collected from two teeth using a periodontal curette. Subgingival plaque was obtained by inserting two sterile paper points into periodontal pockets for 20 s. This was followed by an upper gastrointestinal endoscopy and antral biopsies.

RESULTS:

Sixty-five per cent of patients had dental plaque positive for H pylori and more than 50% harboured the bacteria in their stomach. Periodontitis patients had a significantly higher percentage of H pylori in their dental plaque (79% versus 43%; P<0.05) and the stomach (60% versus 33%; P<0.05) than patients with no periodontitis. Additionally, 78% of patients from the periodontitis group versus only 30% from the nonperiodontitis group had a positive test result for the coexistence of H pylori in both dental plaque and the stomach.

CONCLUSION:

Patients with poor oral hygiene have a higher prevalence of H pylori in dental plaque and in the stomach. This finding suggests that the oral cavity may be a reservoir for H pylori, and potentially a source of transmission or reinfection.     

Comparison between Resectable Helicobacter pylori-Negative and -Positive Gastric Cancers

Background/Aims

Controversy exists regarding the characteristics of Helicobacter pylori infection-negative gastric cancer (HPIN-GC). The aim of this study was to evaluate clinicopathologic features of HPIN-GC compared to H. pylori infection-positive gastric cancer (HPIP-GC) using a comprehensive analysis that included genetic and environmental factors.

Methods

H. pylori infection status of 705 resectable gastric cancer patients was determined by the rapid urease test, testing for anti-H. pylori antibodies, histologic analysis and culture of gastric cancer tissue samples, and history of H. pylori eradication. HPIN-GC was defined as gastric cancer that was negative for H. pylori infection based on all five methods and that had no evidence of atrophy in histology or serology.

Results

The prevalence of HPIN-GC was 4% (28/705). No significant differences with respect to age, sex, smoking, drinking, family history of gastric cancer or obesity were observed between the two groups. HPIN-GC tumors were marginally more likely to involve the cardia (14.3% for HPIN-GC vs 5.3% for HPIP-GC, p=0.068). The Lauren classification, histology, and TNM stage did not differ according to H. pylori infection status. Microsatellite instability was not different between the two groups, but p53 overexpression in HPIN-GC was marginally higher than in HPIP-GC (56.0% for HPIN-GC vs 37.0% for HPIP-GC, p=0.055).

Conclusions

The prevalence of HPIN-GC was extremely low, and its clinicopathologic characteristics were similar to HPIP-GC.     

Study of Biofilm Formation in C57Bl/6J Mice by Clinical Isolates of Helicobacter pylori

Background/Aim:

Despite the significant number of studies on H. pylori pathogenesis, not much data has been published concerning its ability to form biofilm in the host stomach. This study aims to evaluate the potential of clinical isolates of H. pylori to form biofilm in C57BL/6J mice model.

Materials and Methods:

Two strains of H. pylori were selected from a collection of clinical isolates; one (19B), an efficient biofilm producer and the other (4B), with weak biofilm-forming ability. Mice infected through gastric avages were examined after one and two weeks. Colonization was determined by CFU and urease activity; the anti-H. pylori IgA was measured by ELISA, and chronic infections were evaluated by histopathology. Bacterial communities within mucosal sections were studied by immunofluorescence and scanning electron microscopy (SEM).

Results:

Successful infection was obtained by both test strains. Strain 19B with higher ability to form biofilm in vitro also showed a higher colonization rate in the mice stomach one week after infection. Difference (P < 0.05) in IgA titers was observed between the infected mice and the controls as well as between 19B and 4B infected mice, two weeks after the last challenge. Immunofluorescence and SEM results showed tightly colonizing H. pylori in stomach mucosal sections and in squamous and glandular epithelium.

Conclusion:

H. pylori is able to form biofilm in the mouse stomach and induce IgA production, reflecting the same potential as in humans. Firm attachment of coccoid form bacteria to host cells suggests the importance of this state in biofilm formation by H. pylori. Occurrence of biofilm in squamous and glandular epithelium of the mouse stomach proposes that H. pylori can all parts of the upper gastrointestinal tract.     

Sero-prevalence of Helicobacter pylori infection among asymptomatic healthy Omani blood donors

Objective

To investigate the prevalence of Helicobacter pylori (H. pylori) infection, a cross-sectional epidemiological study, based on the age and gender-specific seroprevalence of H. pylori antibodies in asymptomatic healthy Omani blood donors attending the SQUH blood bank.

Methods

Analysis of the sera from 133 apparently healthy subjects, based on the serological determination of the IgM, IgG and IgA antibodies against H. pylori, was carried out using a commercially available kit ELISA (NovaLisa, NovaTec, Germany). While the presence of H. pylori-specific IgG antibodies is the marker for a “chronic” infection with this pathogen. Therefore, there was no indicator of the time of acquisition of the infection. However, the H. pylori-specific IgM antibody was a more specific marker for a recently acquired infection with H. pylori.

Results

Of the 133 subjects, there were 100 (74%) males and 33 (26%) females. The age range was 15 to 50 years with a mean of 25.75±3.75 years. The overall prevalence of H. pylori infection in our study was 69.5%. The overall seroprevalence was found to be increased 69%-86% with age. Subjects between 15–20 years of age showed 71% seroprevalence, while those between 21–40 years showed gradual increase (63%–70%) with age and reached up to 87% in subjects between 41–50 years of age. A significant inverse association was found between sex and age groups. This is when each age group was examined individually; a higher positive percentage of H. pylori antibodies increasing with age was seen in males between 21–40 years of age group in comparison to the females of the same age group. Male subjects with age group between 21 to 40 years were found to have a significant seropositivity compared to the female subjects within the same group. This may reflect how frequent were the male subjects being exposed to the outer environment and their conduct than the females in this society like Oman.

Conclusions

The seropositivity of H. pylori is moderately higher between ages of 21 to 30 more than any other age group.     

Sero-prevalence and factors associated with Helicobacter pylori infection in Eastern Sudan

Objective

To investigate the prevalence of Helicobacter pylori (H. pylori) among patients with dyspepsia and to evaluate the correlation between H. pylori infection and socio-demographic factors.

Methods

This cross-sectional hospital-based study, which ran from June to August 2012, determined seroprevalence of H. pylori among adult patients in Eastern Sudan. The presence of H. pylori was determined using ELISA.

Results

A total of 225 adult Sudanese patients were enrolled in the study. Of these, 148 (65.8%) tested positive for H. pylori. In logistic regression analysis, rural residency (OR=3.933, CI=1.337-11.26, P=0.01) was the only socio-demographic factor that was associated with H. pylori infection. The most common symptoms among seropositive patients were heartburn (OR=30.442, CI=9.478-97.776, P≤0.001) and/or epigastria pain (OR=28.225, CI=4.365-182.508, P≤0.001).

Conclusions

Clinical suspicion can facilitate the detection of H. pylori among patients with dyspeptic symptoms in a geographic area with high prevalence of H. pylori infection.     

Substitutions in Penicillin-Binding Protein 1 in Amoxicillin-Resistant Helicobacter pylori Strains Isolated from Korean Patients

Background/Aims

A worldwide increase in amoxicillin resistance in Helicobacter pylori is having an adverse effect on eradication therapy. In this study, we investigated the mechanism of the amoxicillin resistance of H. pylori in terms of amino acid substitutions in penicillin-binding protein 1 (PBP1).

Methods

In total, 150 H. pylori strains were isolated from 144 patients with chronic gastritis, peptic ulcers, or stomach cancer. The minimum inhibitory concentrations (MICs) of the strains were determined with a serial 2-fold agar dilution method. The resistance breakpoint for amoxicillin was defined as >0.5 µg/mL.

Results

Nine of 150 H. pylori strains showed amoxicillin resistance (6%). The MIC values of the resistant strains ranged from 1 to 4 µg/mL. A PBP1 sequence analysis of the resistant strains revealed multiple amino acid substitutions: Val16→Ile, Val45→Ile, Ser414→Arg, Asn562→Tyr, Thr593→Ala, Gly595→Ser, and Ala599→Thr. The natural transformation of these mutated genes into amoxicillin-sensitive strains was performed in two separate pbp1 gene segments. A moderate increase in the amoxicillin MIC was observed in the segment that contained the penicillin-binding motif of the C-terminal portion, the transpeptidase domain.

Conclusions

pbp1 mutation affects the amoxicillin resistance of H. pylori through the transfer of the penicillin-binding motif.     

A Planned Prospective, Randomized, Placebo-Controlled Multicenter Trial Assessing the Effect of Helicobacter pylori Eradication on the Healing of Iatrogenic Ulcer after Endoscopic Resection of Gastric Neoplasm

Background/Aims

Helicobacter pylori eradication may facilitate the healing of iatrogenic ulcer after endoscopic resection of gastric neoplasm. This study involved designing a randomized, double-blinded, placebo-controlled, multicenter trial, performed by the Korean College of Helicobacter and Upper Gastrointestinal Research and the Medical Research Collaboration Center, Seoul National University Hospital.

Methods

We intend to enroll up to 232 patients H.-pylori-positive patients who have gastric adenoma or early gastric cancer after endoscopic resection. The enrolled patients are being randomly allocated to the H.-pylori-eradication-plus-proton-pump-inhibitor group or the placebo-plus-proton-pump-inhibitor group based on their histology results and the size of the resected specimen. After random allocation, the iatrogenic ulcer size and stage are evaluated at 4- and 8-week follow-ups (with a window of ±7 days). The primary end point is the healing rate of the ulcer by stage, and the secondary end point is the rate of ulcer size reduction, relief rate from ulcer-related symptoms, and adverse-event rates.

Results

More than 90% of the target subjects have already been enrolled into the study and are receiving ongoing periodic monitoring by the Medical Research Collaboration Center.

Conclusions

Completion of the study should reveal whether H. pylori eradication can facilitate the healing of ulcer after endoscopic resection in Korea.