Epidemiology of Helicobacter pylori infection

Helicobacter pylori infection is associated with decreased odds for eosinophilic esophagitis in Mexican patients

BACKGROUND

The incidence of eosinophilic esophagitis (EoE) is increasing in some regions of the world. Retrospective studies have found an inverse association with Helicobacter pylori infection (H. pylori). A recent prospective study has questioned this relationship. We aimed to evaluate this relationship in Mexican patients.

PATIENTS AND METHODS

We evaluated adult patients without prior eradication of H. pylori. Cases were defined by the presence of esophageal symptoms and >15 eosinophils/high power field (HPF) in the esophageal biopsy. Controls were defined by the presence of <15 eosinophils/HPF in esophageal biopsy. H. pylori infection was defined by histology. Patients were matched by age and gender assigning four controls per case.

RESULTS

We included 190 patients: 38 cases and 152 controls. Cases had higher frequency of atopy, dysphagia, food impaction, peripheral eosinophilia, and endoscopic EoE abnormalities. The overall prevalence of H. pylori was 63.6%. Cases had significantly lower prevalence of H. pylori than controls (36.8% vs. 70.4%, OR 0.21 95% CI 0.08-0.69, p = 0.001). Atopic patients had lower prevalence of H. pylori than non-atopic: 13.1% vs. 50.5% (OR 0.20, 95% CI 0.06-0.69, p < 0.001), particularly allergic rhinitis and food allergy.

CONCLUSIONS

We observed an inverse relationship between H. pylori and EoE as well as atopy. Studies in experimental models of EoE that clarify the role of H. pylori in this interaction are required, as well as robust studies that include other factors (socioeconomic, cultural, microbiota, etc.) in order to clarify this relationship.

Novel Information Regarding the Treatment of Helicobacter pylori Infection: A Systematic Review and Meta-analysis of Randomized Clinical Trials

OBJECTIVE

Helicobacter pylori infects at least 50% of the world's human population. The current study aimed to assess and compare the efficacy of triple versus quadruple therapy.

METHODS

Randomized clinical trials (RCTs) consisting of triple and quadruple therapy were identified through electronic and manual searches in the national and international online databases (IsI, Magiran, Embase, PubMed, and Scopus). The random-effects model was applied to pool analysis. Funnel plots and the Egger test were used to examine publication bias.

RESULTS

After a detailed review of the selected articles, 80 RCTs were included in the meta-analysis; it was based on using triple and quadruple therapy as the first and second-line treatment. The results showed that quadruple therapy in the first-line treatment had a higher eradication rate than triple therapy. Overall, the eradication rate with triple therapy was 74% (95% CI, 71%-77%) for intention-totreat (ITT) analysis and 80% (95% CI, 77%-82%) for per-protocol (PP) analysis. Generally, the eradication rate with quadruple therapy was 82% (95% CI, 78.0%-86.0%) for ITT analysis and 85% (95% CI, 82.0%-89.0%) for PP analysis. The analysis also revealed that quadruple therapy was more effective for 7 or 10 days.

CONCLUSION

The current study results demonstrated that quadruple therapy has better effectiveness than triple therapy as the first-line treatment; however, in the second-line treatment, the effectiveness of quadruple and triple regimens is almost similar. The effectiveness of quadruple therapy in the Asian population was found to be slightly higher than that of triple therapy, while this difference was considerably higher in the European population.

Global Trend on Machine Learning in Helicobacter within One Decade: A Scientometric Study

Purpose

This study aims to create a science map, provide structural analysis, investigate evolution, and identify new trends in Helicobacter pylori (H. pylori) research articles.

Methods

All Helicobacter publications were gathered from the Web of Science (WoS) database from August 2010 to 2021. The data were required for bibliometric analysis. The bibliometric analysis was performed with Bibliometrix R Tool. Bibliometric data were analyzed using the Bibliometrix Biblioshiny R-package software.

Results

A total of 17,413 articles were reviewed and analyzed, with descriptive characteristics of the H. pylori literature included. In journals, 21,102 keywords plus and 20,490 author keywords were reported. These articles were also written by 56,106 different authors, with 262 being single-author articles. Most authors' abstracts, titles, and keywords included "Helicobacter-pylori." Since 2010, the total number of H. pylori-related publications has been decreasing. Gut, PLOS ONE, and Gastroenterology are the most influential H. pylori journals, according to source impact. China, the United States, and Japan are the countries with most affiliations and subjects. In addition, Seoul National University has published the most articles about H. pylori. According to the cloud word plot, the authors' most frequently used keywords are gastric cancer (GC), H. pylori, gastritis, eradication, and inflammation. "Helicobacter pylori" and "infection" have the steepest slopes in terms of the upward trend of words used in articles from 2010 to 2021. Subjects such as GC, intestinal metaplasia, epidemiology, peptic ulcer, eradication, and clarithromycin are included in the diagram's motor theme section, according to strategic diagrams. According to the thematic evolution map, topics such as Helicobacter pylori infection, B-cell lymphoma, CagA, Helicobacter pylori, and infection were largely discussed between 2010 and 2015. From 2016 to 2021, the top topics covered included Helicobacter pylori, H. pylori infection, and infection.

Relationship Between Asymptomatic Helicobacter Pylori Infection and BMI Among Patients Undergoing Bariatric Surgery in Saudi Arabia

Background Obesity has become a major health concern associated with several comorbidities. Obesity has been connected to numerous variables. Furthermore, multiple studies were done worldwide to identify the relationship between obesity and Helicobacter pylori (H. pylori), and there was controversy. However, the relationship between H. pylori infection and obesity in our community is still not clear, and there is a knowledge gap. Aim To determine the relationship between asymptomatic H. pylori infection and body mass index (BMI) among patients who underwent bariatric surgery in Saudi Arabia, King Fahad Specialist Hospital - Buraidah (KFSH-B). Method An observational retrospective cohort study was conducted at KFSH-B. Patients with high BMI (>30 kg/m2) who underwent bariatric surgery between January 2017 and December 2019 were included. Gender, age, BMI, and upper GI endoscopy reports of preoperative mapping were collected from electronic health records. Results The sample size was 718, and the mean BMI (standard deviation) was 45 kg (6.8). Patients with positive H. pylori results were 245 (34.1%) and patients with negative H. pylori results were 473 (65.9%). The t-test showed the mean BMI of patients with negative H. pylori results to be 45.36 (SD 6.6). Positive H. pylori 44.95 (SD 7.2) p-value was not significant (0.44). Conclusion The data showed that patients who had undergone bariatric surgery had negative pre-operative histopathological results of H. pylori more than those who had positive results, which is consistent with the prevalence of H. pylori infection among the general population. Therefore, we found no correlation between H. pylori infection and high BMI.

Clarithromycin-based Helicobacter pylori eradication therapy is not associated with higher treatment failure compared with non-clarithromycin-based regimens in a tertiary referral hospital in Switzerland

BACKGROUND AND AIMS

Due to increasing antibiotic resistance, various Helicobacter pylori eradication regimens other than clarithromycin-based therapies have been proposed. However, detailed data on which therapies were employed and their eradication success is lacking. The purpose of this study was to analyse the response rates of different eradication therapy schemes.

METHODS

In this retrospective cohort study, we analysed data of 1721 patients and included 608 patients undergoing H. pylori eradication therapy at the Department of Gastroenterology at the University Hospital Zurich between 2004 and 2018. The primary endpoint was the success rates of clarithromycin- and non-clarithromycin-containing H. pylori eradication regimens. We furthermore analysed factors with potential impact on the outcome of H. pylori eradication therapies, such as demographics, and smoking and social status.

RESULTS

The most common therapy scheme (71% of all cases) was proton pump inhibitor (PPI)-amoxicillin-metronidazole, followed by PPI-amoxicillin-clarithromycin (21%) and PPI-metronidazole-clarithromycin (6%). There was no difference between the H. pylori eradication success of clarithromycin vs non-clarithromycin-containing therapies (71% vs 71%, p = 0.764).

CONCLUSION

Despite increasing clarithromycin resistance globally, there was no difference in the eradication success of clarithromycin- and non-clarithromycin-containing therapy regimens in Switzerland. As varying triple therapies do not increase eradication rates in real-world settings, other primary therapy options such as quadruple therapies should be explored.

A Bioluminescence-Based Drug Screen Identifies Activities of Fexinidazole and Its Metabolites against Helicobacter pylori

Helicobacter pylori is responsible for a wide range of gastric diseases, including gastric cancer and gastritis. With half of the world’s population infected by H. pylori and the current standard of care associated with suboptimal outcomes, a search for more effective drugs is critical. To facilitate drug screening for H. pylori, we developed a microtiter plate-based compound screening method that is faster and can screen multiple compounds. We identified activities of fexinidazole and its sulfoxide and sulfone metabolites against H. pylori. Both fexinidazole and its metabolites exhibited equipotency against SS1, 60190, and G27 strains, which were about 3–6-fold more potent than the currently used metronidazole. We also determined the minimal inhibitory concentration (MIC) of metronidazole, fexinidazole, and its metabolites against these strains by a traditional agar plate-based method. While MIC values of fexinidazole and metronidazole were similar against all the strains, both sulfoxide and sulfone showed lower MIC values than metronidazole against SS1 and 60190. Given the recent FDA approval of fexinidazole, our data on the in vitro antibacterial activities of fexinidazole and its metabolites support further evaluation of this drug with the goal of producing an alternative nitro-based antimicrobial with good safety profiles for the treatment of H. pylori infection.

The relationship between helicobacter pylori infection and nodular antral gastritis in pediatric patients

BACKGROUND

Helicobacter pylori (H. pylori) is a spiral-shaped gram-negative bacterium that colonizes the gastric mucosa. It is a common infectious agent in children. In this study, we aim to evaluate the demographic data, and the clinical and histopathological findings of pediatric patients that underwent upper gastrointestinal endoscopy (UGSE) in our clinic.

METHODS

Between July 2017 and February 2019, 636 patients applied to the Selcuk University Faculty of Medicine, Pediatric Gastroenterology outpatient clinic with complaints of epigastric abdominal pain and/or dyspeptic complaints. Patients who underwent upper gastrointestinal endoscopy were evaluated retrospectively. Data on age, gender, family history of peptic ulcer disease, and family history of H. pylori were recorded. Endoscopic and histopathological findings were collected from medical records.

RESULTS

235 (36.9%) of the patients participating in the study were male, and 401 (63.1%) were female. H. pylori infection was detected in 277 (43.6%) patients as a result of histopathological examination of H. Pylori, urea breath tests and H. Pylori antigen tests in the stools of patients are included in the study. Nodular antral gastritis was detected in 282 (44.3%) of our patients endoscopically. H. pylori was detected in 83.7% (n: 236) of the 282 patients with nodular antral gastritis. Nodular antral gastritis was observed to be significantly higher in H. pylori-positive patients than in H. pylori-negative cases (odds ratio (OR), 39.16; 95% confidence interval (CI), 24.88-61.64; p: <0.001).

CONCLUSION

Nodular antral gastritis is caused by chronic H. pylori infection. It is predicted that early detection of H. pylori infection in children is important and may decrease complications later in life. Our study shows that all the markers evaluated are very good predictors of H. pylori infection. Positive significant association was found between the prevalence of H. pylori infection and nodular antral gastritis.

Predictive Factors for Future Onset of Reflux Esophagitis: A Longitudinal Case-control Study Using Health Checkup Records

Background/Aims

Although risk factors of reflux esophagitis (RE) have been investigated in numerous cross-sectional studies, little is known about predictive factors associated with future onset of RE. We investigated time courses of clinical parameters before RE onset by a longitudinal case-control study using health checkup records.

Methods

We used health checkup records between April 2004 and March 2014 at 9 institutions in Japan. A multivariate logistic regression analysis was performed to evaluate associations of baseline clinical parameters with RE. The time courses of the clinical parameters of RE subjects were compared with those of non-RE subjects by the mixed-effects models for repeated measures analysis or longitudinal multivariate logistic analysis.

Results

Initial data were obtained from 230 056 individuals, and 2066 RE subjects and 4132 non-RE subjects were finally included in the analysis. Body mass index, alanine aminotransferase, smoking, acid reflux symptoms, hiatal hernia, and absence of atrophic gastritis at baseline were independently associated with RE. The time courses of body mass index, fasting blood sugar, triglyceride, aspartate aminotransferase, alanine aminotransferase, ^γ-glutamyl transpeptidase, percentages of acid reflux symptoms, feeling of fullness, and hiatal hernia in the RE group were significantly worse than in the non-RE group.

Conclusions

The RE group displayed a greater worsening of the clinical parameters associated with lifestyle diseases, including obesity, diabetes, hyperlipidemia, and fatty liver for 5 years before RE onset compared with the non-RE group. These results suggest that RE is a lifestyle disease and thus lifestyle guidance to at-risk person may help to prevent RE onset.

Prevalence of Helicobacter pylori among Patients with Gastrointestinal Tract (GIT) Symptoms: A Retrospective Study at Selected Africa Air Rescue (AAR) Clinics in Kampala, Uganda, from 2015 to 2019

Background

Helicobacter pylori (HP) infection is extremely common worldwide, with almost half of the world's population infected. In Uganda, no study has been done on the trends of the prevalence of H. pylori infection in the affluent population. Therefore, this retrospective cross-sectional study aimed at determining the trend of H. pylori prevalence among affluent patients presenting with gastrointestinal (GIT) symptoms whose stool samples were tested at selected AAR clinics in Kampala area. Patients were tested for Helicobacter pylori infection using the stool antigen test between January 2015 and December 2019.

Results

The overall 5-year H. pylori prevalence was 35.7% (1298/3634). The prevalence was higher in males (36.0% (736/2044)) than in females (35.4% (562/1590)), although not statistically significant (OR = 0.97, p = 0.680, 95% CI: 0.84–1.11). The prevalence of H. pylori infection was significantly higher (39.4%) among patients who belonged to the age group of 19–35 years (OR = 1.49, p < 0.001, 95% CI: 1.22–1.82). The prevalence for H. pylori among the age group of 19–35, the most productive age, could be attributed to work-related factors such as stress. The highest prevalence (43.4%) was recorded in 2018 and the lowest (21.4%) in 2015; however, the trend of H. pylori infection in the 5 years was fluctuating.

Conclusion

H. pylori infestation is a preserve of not only the poor but also the elites. Stressful factors, especially in the age group of 19–35 years, should be appropriately managed.

IL-9 contributes to the host immune response against Helicobacter pylori and helps limit infection in a Mouse Model

BACKGROUND

As an important mediator in lots of diseases, interleukin-9 (IL-9) can be a protector or pro-inflammatory cytokine depending on the complicated inflammatory milieu. Helicobacter pylori (H. pylori) induced a series of immunology cells and cytokines change, and however, the role of IL-9 in H. pylori infection remains unknown.

MATERIALS AND METHODS

Wild-type and IL-9 deficient mice were infected with H. pylori by means of intragastric administration. The colonization of H. pylori bacteria was measured by detecting specific 16s rDNA, and the intensity of inflammation was observed by H&E stain. The expression level of inflammation cytokines was determined by ELISA and quantitative real-time PCR.

RESULTS

IL-9 was increased due to the attack of H. pylori, besides deletion of Il9 aggravated the bacterial colonization and inflammation intensity. In addition, treatment of rmIL-9 reduced colonized H. pylori and inflammation level, indicated that IL-9 was a protector for the host against this bacterium. Followed by the H. pylori infection, interferon (IFN)-γ and interleukin (IL)-17A were up-regulated as expected, and nevertheless, the expression of IL-17A shared a positive relationship with IL-9 while IFN-γ negative associated with IL-9. Moreover, we also proved that Treg cells were not involved in the protective effect of IL-9, and meanwhile, CD4⁺ CD25^- T cells secreted more IFN-γ and less IL-17A in vitro due to the deletion of Il9.

CONCLUSIONS

IL-9 plays a protective role against H. pylori and the protection associated with cytokines change including IFN-γ and IL-17A.

Investigation the levels of endotoxin and 8-hydroxy-2'-deoxyguanosine in sera of patients with Helicobacter pylori-positive peptic ulcer

BACKGROUND

Peptic ulcer is considered an important public health problem and generally associated with complicated conditions such as bleeding and perforation. The aim of this study is to reflect the rate of oxidative damage in the body among dyspeptic patients with Helicobacter pylori-positive peptic ulcer by measuring 8-hydroxy-2'-deoxyguanosine (8-OHdG) level in serum samples and its association with the level of bacterial endotoxin.

METHODS

Patients referred to Harran University Gastroenterology Outpatient Clinic with dyspeptic complaints were enrolled in this study. According to gastrointestinal endoscopy findings, 43 dyspeptic patients with H pylori-positive peptic ulcer patients and 43 healthy volunteers were included in this study. Infection with H pylori was diagnosed by H pylori urea breath and stool antigen tests. Serum 8-OHdG and endotoxins were measured by ELISA.

RESULTS

A total of 43 dyspeptic patients with peptic ulcer (13 women and 30 men) and 43 healthy individuals (16 women and 27 men) were enrolled in the study. In biopsies taken endoscopically, H pylori severity was mild in 19 patients (43.9%), moderate in 21 patients (48.5%) and severe in 3 patients (7.6%). 8-OHdG was compared with the healthy and patient group. It was observed that there was a statistically significant difference (P < .01). In addition, a weak correlation was found between OHdG and bacterial endotoxin.

CONCLUSION

Serum 8-OHdG and endotoxin levels are only weakly associated implying that they reflect specific aspects of oxidative damage. Helicobacter pylori and its endotoxin have a significant role in peptic ulcer pathogenesis. The detection of serum 8-OHdG in dyspeptic patients may be used as a biomarker for the presence of peptic ulcers.

The effects of Helicobacter pylori infection on pregnancy-related diseases and fetal development in diabetes in pregnancy

Background

This study aimed to determine the association of Helicobacter pylori (H. pylori) infection with pregnancy-related diseases and fetal development in women with diabetes in pregnancy (DIP).

Methods

All the participants were recruited before 16 weeks of gestation. According to their medical history and the results of a 75-g oral glucose tolerance test at the 24^th week of pregnancy, the participants were divided into a normal control group (NC group), a gestational diabetes mellitus group (GDM group), and a pre-pregnancy diabetes mellitus group (PGDM group). According to the results of an H. pylori serum antibody detection test, each group was further divided into two subgroups: an H. pylori positive subgroup (HP+ subgroup) and an H. pylori negative group (HP- subgroup). The incidences of pregnancy-related diseases, the fetal developmental status, and the newborn status were compared among the groups.

Results

This study recruited 356 pregnant women. The infection rates of type I H. pylori were significantly higher in the GDM group and the PGDM group than in the NC group (χ²=6.949, P=0.031). With the exception of the NC-HP+ subgroup, there were higher incidences of pregnancy-related diseases in the HP+ subgroups than in the HP− subgroups (P<0.05). Furthermore, the incidences of pregnancy-induced hypertension (PIH), preeclampsia, and premature delivery were significantly higher in the GDM-HP+ subgroup and the PGDM-HP+ subgroup than in the NC-HP+ subgroup (P<0.05). At the end of pregnancy, all 3 HP− subgroups showed better fetal development than the HP+ subgroups (P<0.05), and the NC-HP+ subgroup showed better fetal development than the GDM-HP+ and PGDM-HP+ subgroups (P<0.05). Meanwhile, the PGDM-HP+ subgroup showed poor fetal development, even in the 2^nd trimester of pregnancy.

Conclusions

H. pylori infection is extremely common in DIP. For women with DIP, infection with H. pylori can increase the risks of pregnancy-related diseases and poor fetal development. H. pylori screening and eradication therapy before pregnancy may aid in preventing pregnancy-related diseases and improve fetal development.

Helicobacter pylori Prevalence and Impact: A Histology-Based Report About Children from an Endemic Country

Background

Helicobacter pylori is spreading worldwide with a high prevalence rate in the developing countries. Our primary goal was to measure the histology-based prevalence of Helicobacter pylori infection in children and to quantify its impact on the gastric inflammation and anemia. Our secondary goal was to study possible predictors for the presence of Helicobacter pylori in this cohort.

Methods

A retrospective chart review was performed for children who underwent Esophago-gastro-duodenoscopy at Jordan university hospital in Jordan from 2008 to 2016. Data collected included epidemiological data, indication for endoscopy, endoscopic findings, and laboratory data. The gastric biopsies were re-examined by a pathologist to check for the presence of Helicobacter pylori, the presence of gastritis, and to grade gastritis according to the updated Sydney criteria.

Results

A total of 98 children (53 girls-54%) underwent Esophago-gastro-duodenoscopy. The average age was 11.7 years ± 4.7 years. Of them, 53 patients (29 boys-55%) had Helicobacter pylori identified in the gastric biopsy. The histology-based prevalence rate of Helicobacter pylori was 54%. The most common indication for endoscopy was abdominal pain (53%) followed by vomiting (18%). Nodular gastric mucosa was present in 43% of the Helicobacter pylori-positive group, and in only 11% of the Helicobacter pylori-negative group (P-value <0.0.5). Moderate to severe chronic gastritis was seen in 59% of the biopsies of Helicobacter pylori-positive group, compared to 31% in the Helicobacter pylori-negative group (p value <0.05). Presence of anemia was not different between the two groups (p value > 0.05). Presence of endoscopic nodularity, active gastritis by histology, and moderate to severe gastritis by histology were positive predicators for the presence of Helicobacter pylori. (p value <0.05).

Conclusion

Helicobacter pylori infection in this study cohort of Jordanian children is common, with a histology-based prevalence rate of 54%. Nodularity of the stomach is the most common positive endoscopic feature, and its presence predicts the presence of Helicobacter pylori. Moderate to severe active gastritis is associated with Helicobacter pylori. The presence of Helicobacter pylori does not affect anemia status in this cohort of Jordanian children.

A comparative proteomic approach using metabolic pathways for the identification of potential drug targets against Helicobacter pylori

BACKGROUND

Helicobacter pylori is the most highlighted pathogen across the globe especially in developing countries. Severe gastric problems like ulcers, cancers are associated with H. pylori and its prevalence is widespread. Evolution in the genome and cross-resistance with different antibiotics are the major reason of its survival and pandemic resistance against current regimens.

OBJECTIVES

To prioritize potential drug target against H. pylori by comparing metabolic pathways of its available strains.

METHODS

We used various computational tools to extract metabolic sets of all available (61) strains of H. pylori and performed pan genomics and subtractive genomics analysis to prioritize potential drug target. Additionally, the protein interaction and detailed structure-based studies were performed for further characterization of protein.

RESULTS

We found 41 strains showing similar set of metabolic pathways. However, 19 strains were found with unique set of metabolic pathways. The metabolic set of these 19 strains revealed 83 unique proteins and BLAST against human proteome further funneled them to 38 non-homologous proteins. The druggability and essentiality testing further converged our findings to a single unique protein as a potential drug target against H. pylori.

CONCLUSION

We prioritized one protein-based drug target which upon subject to applied protocol was found as close homolog of the Saccharopine dehydrogenase. Our study has opened further avenues of research regarding the discovery of new drug targets against H. pylori.

Comparison of 10-Day Course of Triple Therapy Versus 14-Day Course for Eradication of Helicobacter pylori Infection in an Indonesian Population: Double-Blinded Randomized Clinical Trial

Objective:

The aim of this study was to compare the effectiveness of 10-day course of triple therapy versus a 14-day course in the treatment of H.pylori infection in an Indonesian population.

Methods:

A double-blinded randomized clinical trial was included patients, Indonesian population, with H.pylori infection conducted in Cipto Mangunkusumo Hospital, Jakarta; Cilincing District General Hospital, Jakarta; and West Nusa Tenggara General Hospital, Mataram, during October 2016 - April 2017. Patients were randomized to be given triple therapy as Rabeprazole 20 mg, Amoxicillin 1,000 mg, and Clarithromycin 500 mg twice daily, for 14 days or 10 days plus 4 days placebo. Eradication was evaluated with UBT at least 4 weeks after completion the therapy.

Results:

A total of 75 patients (38 in the 14-day group and 37 in the 10-day group) were included to the study. In the intention-to-threat analysis, eradication rate was 67.6% (95% CI. 52.5%-82.6%) for the 10-day group versus 86.8% (95% CI. 76.0%-97.5%) for the 14-day group (p = 0.046), whereas per protocol analysis obtained 73.5% (95% CI. 58.6%-88.3%) for the 10-day versus 91.9% (95% CI. 84.1%-99.6%) in the 14-day group (p = 0.039). Adverse events were not significantly different between the two groups.

Conclusion:

A 14-day course was more effective than 10-day course of triple therapy as first-line for eradication of H.pylori infection in an Indonesian population.

Where are we today with Helicobacter pylori infection among healthy children in Saudi Arabia?

BACKGROUND/AIMS

The available studies on Helicobacter pylori (H. pylori) prevalence among healthy asymptomatic population across Saudi Arabia suffers from significant limitations. We conducted this large population-based study to estimate the H. pylori seropositivity rate among apparently healthy children in Saudi Arabia, using anti-H. pylori immunoglobulin A (IgA) and IgG serology tests, and to study the influence of H. pylori infection on growth.

MATERIALS AND METHODS

We conducted a cross-sectional study to screen apparently healthy school aged Saudi children (aged 6-15 years), attending primary and intermediate schools in Riyadh between 2014 and 2016, for H. pylori seropositivity by checking for the presence of anti-H. pylori IgG and IgA antibodies in serum specimens.

RESULTS

Out of 3551 serum specimens, 1413 cases tested seropositive for H. pylori organism (40%): 430 (12.2%) were both IgG and IgA positive, 212 (6%) and 771 (21.7%) cases showed isolated positivity for IgG or IgA, respectively. Male gender, older age, lower levels of socioeconomic status (SES), and family members >10 were significantly associated with H. pylori seropositivity. The proportion of participants with short stature was significantly more in the H. pylori seropositive group than the seronegative group (OR1.249, confidence interval [1.020-1.531], P= 0.033). There was no significant association between H. pylori seropositivity and gastrointestinal symptoms.

CONCLUSION

The prevalence of H. pylori seropositivity among apparently healthy Saudi children (40%) is intermediate compared with that in developed and developing countries. The Saudi pediatric population shows a predominant IgA-type immunological response to H. pylori infection.

Review of current diagnostic methods and advances in Helicobacter pylori diagnostics in the era of next generation sequencing

Helicobacter pylori (H. pylori) infection is highly prevalent in the human population and may lead to severe gastrointestinal pathology including gastric and duodenal ulcers, mucosa associated tissue lymphoma and gastric adenocarcinoma. In recent years, an alarming increase in antimicrobial resistance and subsequently failing empiric H. pylori eradication therapies have been noted worldwide, also in many European countries. Therefore, rapid and accurate determination of H. pylori’s antibiotic susceptibility prior to the administration of eradication regimens becomes ever more important. Traditionally, detection of H. pylori and its antimicrobial resistance is done by culture and phenotypic drug susceptibility testing that are cumbersome with a long turn-around-time. Recent advances in diagnostics provide new tools, like real-time polymerase chain reaction (PCR) and line probe assays, to diagnose H. pylori infection and antimicrobial resistance to certain antibiotics, directly from clinical specimens. Moreover, high-throughput whole genome sequencing technologies allow the rapid analysis of the pathogen’s genome, thereby allowing identification of resistance mutations and associated antibiotic resistance. In the first part of this review, we will give an overview on currently available diagnostic methods for detection of H. pylori and its drug resistance and their implementation in H. pylori management. The second part of the review focusses on the use of next generation sequencing technology in H. pylori research. To this end, we conducted a literature search for original research articles in English using the terms “Helicobacter”, “transcriptomic”, “transcriptome”, “next generation sequencing” and “whole genome sequencing”. This review is aimed to bridge the gap between current diagnostic practice (histology, rapid urease test, H. pylori culture, PCR and line probe assays) and new sequencing technologies and their potential implementation in diagnostic laboratory settings in order to complement the currently recommended H. pylori management guidelines and subsequently improve public health.

Cost-effectiveness of Helicobacter pylori test and eradication versus upper gastrointestinal series versus endoscopy for gastric cancer mortality and outcomes in high prevalence countries

Background: The latest version of Japanese guidelines for effective secondary prevention of gastric cancer recommend upper gastrointestinal series (UGI) and endoscopy in adults 50 years of age and older. A Helicobacter pylori antibody test and eradication (H. pylori screening) reduces gastric cancer risk. Objective: This study aimed to evaluate the cost-effectiveness of H. pylori screening, compared to UGI and endoscopy in high prevalence countries. Methods: We developed decision trees with Markov models using a healthcare payer perspective and a lifetime horizon. Targeted populations were hypothetical cohorts of asymptomatic individuals at the age of 50, 60, 70 and 80 years. We calculated per-person costs and effectiveness with discounting at a fixed annual rate of 3% and compared incremental cost-effectiveness ratios. Results: H. pylori screening was cost-saving and more cost-effective for individuals at the age of 50, 60, 70, and 80 than UGI and endoscopy. One-way and multiway sensitivity analyses showed the robustness of the cost-effectiveness results. Probabilistic sensitivity analyses using Monte-Carlo simulation for 10,000 trials demonstrated that H. pylori screening was cost-effective 100% of the time at a willingness-to-pay level of US$50,000/QALY gained. Conclusions: H. pylori screening for the adults 50 years of age and older could be cost-effective compared to UGI and endoscopy in high prevalence countries. The main reasons for the superiority of H. pylori screening are that an H. pylori antibody test has a higher sensitivity and specificity than UGI and endoscopy and the benefits to reduce gastric cancer incidence and mortality.

The relationship between gastric microbiota and gastric disease

Traditionally, the stomach was believed to be a sterile organ unsuitable for microbiota growth. However, the discovery of H. pylori subverted this conception. With the development of molecular techniques, an abundance of microbiota of great diversity was found in the stomach. In addition, various lines of evidence suggest that the gastric microbiota plays a critical role in the development and progression of the gastric disease.The gastrointestinal microbiome plays an important role in various physiologic and pathologic processes.

Helicobacter pylori infection among patients presenting with dyspepsia at a primary care setting in Cameroon: seroprevalence, five-year trend and predictors

Background

Almost half the world’s population is infected with Helicobacter pylori (H. pylori) with the highest reported prevalence from Africa. This infection is associated with several morbid gastrointestinal conditions. Understanding the trends in seroprevalence and the factors associated with H. pylori seropositivity in dyspeptic persons can provide a guide for public health policies.

Methods

This was a retrospective study, carried out with outpatient records of Wum District Hospital (WDH) from January 2012 to December 2016. We reviewed records of all patients for whom a H. pylori serology test was requested. The Cochran-Armitage trend test and multiple regression models were used to explore seroprevalence trends and predictors of seropositivity respectively.

Results

We included 451 records, 63.6% (n = 287) were female. The mean age of the study population was 40.7 years, and the overall H. pylori seroprevalence was 51.5% (95% CI: 47–56%). The use of recommended eradication regimen appears to be low and declining. On average, H. pylori seroprevalence declined by 6.8% annually (p < 0.0001). Occupational status independently predicted seropositivity, with students having lower odds of being seropositive than employed persons (aOR = 0.09, 95% CI: 0.02–0.49, p = 0.016).

Conclusion

Despite decreasing trends, the seroprevalence of Helicobacter pylori infection is high in dyspeptic patients attending this primary care setting. Improving living standards and establishing national guidelines for eradication can possibly aid the control of this infection.

Current and Future Treatment of Helicobacter pylori Infections

Helicobacter pylori is one of the most common human pathogens and it has been estimated that about 50% of the world's population is currently infected. The present consensus is that, unless there are compelling reasons, all H. pylori infections should be cured. Since the 1990s, different national and international guidelines for the management of H. pylori-related diseases have been published and periodically updated regarding indications for treatment, diagnostic procedures, and preferred treatment regimens. Most guidelines provide sophisticated meta-analyses examining the outcome of different regimens done in regions with variable, often high rates of resistance to antibiotics, for which the prevalence and effects of resistance was often ignored. Although successful antimicrobial therapy must be susceptibility-based, increasing antimicrobial resistance and general unavailability of susceptibility testing have required clinicians to generally rely on empiric regimens. Antibiotics resistance of H. pylori has reached alarming high levels worldwide, which has an effect to efficacy of treatment. The recommendations should provide regimes for multi-resistant infections or for those where susceptibility testing is unavailable or refused. The first rule is to use only proven locally effective therapies. Because of patient intolerances, drug allergies, and local experiences, the clinicians should have at least two options for first-line therapy. As with any antimicrobial therapy, a thorough review of prior antibiotic use is invaluable to identify the presence of probably resistance. The second key is patient education regarding potential and expected side-effects and the importance of completing the course of antibiotics. We also review here triple therapies, sequential-concomitant, hybrid therapies, bismuth therapies, dual therapy, vonoprazan, modern antibiotic treatments, probiotics and vaccination.

Hepcidin correlates with interleukin-1β and interleukin-6 but not iron deficiency in children with Helicobacter pylori infection

BACKGROUND

Helicobacter pylori infection is associated with iron deficiency (ID) in children. Inflammatory cytokine reactions could influence the consequences of H. pylori infection. Hepcidin is an important regulator in iron homeostasis and could be induced by chronic inflammation. The relationship between hepcidin and cytokine levels in children infected with H. pylori remains controversial.

METHODS

Based on serology testing for anti-H. pylori IgG, participants (43 seropositive and 43 seronegative) aged 10-18 years were enrolled. Serum hepcidin levels and iron profiles, including iron, ferritin, and total iron-binding capacity, were measured. ID is defined as iron saturation less than 15%. Seropositive children were divided into low hepcidin (n = 22) and high hepcidin (n = 21) groups. IL-1β, IL-6, and IL-8 serum levels were compared.

RESULTS

Serum IL-1β and IL-6 levels were comparable between H. pylori seropositive and seronegative children, as were the median serum hepcidin levels (6.5 ng/mL versus 8.6 ng/mL; P = 0.1318). Median levels of serum iron, ferritin, and iron saturation were significantly lower in seropositive children with low hepcidin than in those with high hepcidin (P = 0.0123, P = 0.0001, and P = 0.0004, respectively). The prevalence of ID was significantly higher in those with low serum hepcidin levels (33.3% versus 4.5%; P = 0.015). Compared to the high hepcidin seropositive group, the low hepcidin group had significantly lower median serum levels of cytokines IL-1β and IL-6, but not IL-8 (P = 0.0151 and P = 0.0015, respectively).

CONCLUSIONS

Inflammatory cytokines IL-1β and IL-6, but not IL-8, might be associated with increased hepcidin levels among H. pylori-seropositive children. Further studies are needed to clarify the role of hepcidin.

H. pylori-associated pathologic findings among Alaska native patients

Helicobacter pylori infection is common among Alaska native (AN) people, however scant gastric histopathologic data is available for this population. This study aimed to characterise gastric histopathology and H. pylori infection among AN people. We enrolled AN adults undergoing upper endoscopy. Gastric biopsy samples were evaluated for pathologic changes, the presence of H. pylori, and the presence of cag pathogenicity island-positive bacteria. Of 432 persons; two persons were diagnosed with gastric adenocarcinoma, two with MALT lymphoma, 40 (10%) with ulcers, and 51 (12%) with intestinal metaplasia. Fifty-five per cent of H. pylori-positive persons had cag pathogenicity island positive bacteria. The gastric antrum had the highest prevalence of acute and chronic moderate-severe gastritis. H. pylori-positive persons were 16 and four times more likely to have moderate-severe acute gastritis and chronic gastritis (p < 0.01), respectively. An intact cag pathogenicity island positive was correlated with moderate-severe acute antral gastritis (53% vs. 31%, p = 0.0003). H. pylori-positive persons were more likely to have moderate-severe acute and chronic gastritis compared to H. pylori-negative persons. Gastritis and intestinal metaplasia were most frequently found in the gastric antrum. Intact cag pathogenicity island positive was correlated with acute antral gastritis and intestinal metaplasia.

Antimicrobial resistance among Helicobacter pylori isolates in Alaska, 2000-2016

OBJECTIVES

Alaska Natives experience a high burden of Helicobacter pylori infection and concomitant high rates of gastric cancer. Additionally, the prevalence of antimicrobial-resistant H. pylori has been shown to be high in Alaska. In this study, antimicrobial resistance over time among sentinel surveillance isolates was evaluated and risk factors for carrying antimicrobial-resistant H. pylori were assessed.

METHODS

Through Alaska's H. pylori sentinel surveillance system, antral and fundal biopsies from Alaska Native patients undergoing esophagogastroduodenoscopy for clinical indications during 2000-2016 were collected and cultured. For positive cultures, minimum inhibitory concentrations (MICs) of metronidazole, amoxicillin, clarithromycin, tetracycline and levofloxacin were determined.

RESULTS

A total of 800 H. pylori isolates obtained from 763 patients were tested. Resistance to metronidazole was most common (342/800; 42.8%), followed clarithromycin (238/800; 29.8%), both clarithromycin and metronidazole (128/800; 16.0%) and levofloxacin (113/800; 14.1%). Low proportions of isolates were resistant to amoxicillin and tetracycline. Levofloxacin resistance increased between 2000 and 2016 (P<0.001), but resistance to other antimicrobials did not change over time. Metronidazole and clarithromycin resistance were more common among women (P<0.001 for both), whilst levofloxacin resistance was more common among those with an urban residence (P=0.003). Metronidazole and levofloxacin resistance were more common among older patients (P<0.05).

CONCLUSION

Between 2000 and 2016, a large percentage of H. pylori isolates received by the Alaska Sentinel Surveillance System demonstrated resistance to common antimicrobials. The surveillance system provides valuable information for clinicians to make informed treatment choices for patient with H. pylori.

Cost-effectiveness ofHelicobacter pyloriscreening followed by eradication treatment for employees in Japan

Gastric cancer is the third leading cause of cancer death worldwide. Gastric cancer screening using upper gastrointestinal series, endoscopy and serological testing has been performed in population-based (employee-based and community-based) and opportunistic cancer screening in Japan. There were 45 531 gastric cancer deaths in 2016, with the low screening and detection rates.Helicobacter pylori(H. pylori) screening followed by eradication treatment is recommended in high-risk population settings to reduce gastric cancer incidence. The aim of this study was to evaluate the cost-effectiveness ofH. pyloriscreening followed by eradication treatment for a high-risk population in the occupational health setting. Decision trees and Markov models were developed for two strategies;H. pyloriantibody test (HPA) screening and no screening. Targeted populations were hypothetical cohorts of employees aged 20, 30, 40, 50 and 60 years using a company health payer perspective on a lifetime horizon. Per-person costs and effectiveness (quality-adjusted life-years) were calculated and compared. HPA screening yielded greater benefits at the lower cost than no screening. One-way and probabilistic sensitivity analyses using Monte-Carlo simulation showed strong robustness of the results.H. pyloriscreening followed by eradication treatment is recommended to prevent gastric cancer for employees in Japan, on the basis of cost-effectiveness.

Helicobacter pylori infection, gestational diabetes mellitus and insulin resistance among pregnant Sudanese women

Objectives

To assess the association between Helicobacter pylori (H. pylori) infection and insulin resistance among pregnant Sudanese women attending Saad Abuelela hospital (Khartoum). A cross-sectional study was conducted from 1st July 2017 to 31st January 2018. One hundred and sixty-six women were enrolled and underwent testing for H. pylori IgG antibodies using specific ELISA kits. The Quantitative insulin sensitivity check index (QUICKI) was computed from the fasting insulin and glucose levels.

Results

Median age, gravidity and gestational age were 27 years, 2 and 26 weeks, respectively. Twenty (12%) women were found to have gestational diabetes mellitus (GDM). H. pylori IgG seroprevalence was 66.0% among the study population. Univariate analysis showed that H. pylori-seropositivity was significantly higher among women who have GDM while Log (Homeostatic Model Assessment-β) HOMA-B% was lower (P value = 0.038, and 0.028) respectively. There was no difference between the GDM group and the other group in terms of demographics, body mass index, haemoglobin and QUICKI index results. In multivariate analysis, a higher prevalence of H. pylori was associated with GDM (OR = 2.8, 95% CI  1.1–7.5, P = 0.036). The current study concludes that an increased prevalence of H. pylori is a risk factor for the development of GDM.

Potential Association of IL1B Polymorphism With Iron Deficiency Risk in Childhood Helicobacter pylori Infection

OBJECTIVE

Helicobacter pylori infection occurs predominantly in childhood. Host immune response gene polymorphism is reported to affect the susceptibility to H pylori infection and the outcome of H pylori-related gastric cancer. Not all H pylori-infected patients, however, exhibit iron deficiency (ID). The relationship between host genetic polymorphisms and ID mediated by H pylori infection is not well understood.

METHODS

Subjects (n = 644) from the general population of age 10 to 18 years were divided into 2 groups based on serology testing for anti-H pylori IgG: seropositive study group; and seronegative control group. Five single nucleotide polymorphisms (SNPs) in IL1B (rs1143627 and rs16944), IL8 (rs4073), IL10 (rs1800896), and ABO (rs505922), were genotyped and the iron status of the 2 groups was compared.

RESULTS

The seroprevalence rate for H pylori was 10.7% in this study. Infected subjects were significantly older and had lower serum iron levels than uninfected subjects (P = 0.0195 and 0.0059, respectively). Multivariate analysis revealed a significantly higher frequency of the T allele of rs505922 (odds ratio [OR] = 6.128; P < 0.001) and lower frequency of the T allele of rs1143627 (OR = 0.846; P = 0.014) in seropositive subjects. Among 59 seropositive subjects, the T allele frequency of rs1143627 was significantly higher in those with ID (OR = 3.156; P = 0.043), compared with those without ID.

CONCLUSIONS

ABO (rs505922) and IL1B (rs1143627) may affect H pylori infection susceptibility, and IL1B (rs1143627) may also influence ID risk in infected children.

Peptic Ulcer Disease and Helicobacter pylori Infection in Different Siberian Ethnicities

BACKGROUND

The high prevalence of Helicobacter pylori (H. pylori) infection in eastern Siberia is consistently established. In the same geographic area, however, fragmentary information is available on the epidemiology of the peptic ulcer disease (PUD).

AIM

To assess the prevalence of H. pylori infection (including CagA status) and PUD in different eastern Siberian ethnicities.

PATIENTS AND METHODS

An endoscopy population of 3149 eastern Siberian dyspeptic patients was considered [1727 Europoids and 1422 Mongoloids (Evenks = 792; Khakases = 630)]. H. pylori status was assessed by urease test and/or serum anti-H. pylori IgG and/or histology. CagA status was serologically assessed (anti-CagA antibodies).

RESULTS

All the Siberian ethnicities featured high rates of H. pylori infection (Europoids = 87.1%, Evenks = 88.6%, Khakases = 85.4%). Among the 1504 H. pylori-positive Europoids, the prevalence of CagA-positive status (68.7%) was significantly higher than that featured by the 1240 H. pylori-positive Mongoloid ethnicities (46.9%; p < .001 for both comparisons). Peptic ulcer disease significantly prevailed among Europoids (prevalence among Europoid Evenks and Khakases: 8.9% and 8.3%, respectively; prevalence among Mongoloid Evenks and Khakases = 1.0% and 4.4%, respectively).

CONCLUSIONS

eastern Siberian populations feature consistent high rates of H. pylori infection, but different prevalence of peptic ulcer disease. In particular, Europoids featured a prevalence of both CagA-positive status and peptic ulcer disease significantly higher than that of the Mongoloid ethnicities. These results suggest that both environmental factors (coexisting with the H. pylori infection) and host-related variables modulate the clinicopathological expression of the H. pylori -associated gastric diseases.

Thrombocytopenia and infections

INTRODUCTION

Acquired thrombocytopenia recognizes a myriad of causes. Among these, infectious diseases play a relevant role since a low platelet count is commonplace along with other abnormal laboratory data. Areas covered: This narrative review, after a brief presentation of the possible pathogenic mechanisms, is focused on the most prevalent infections associated with thrombocytopenia, namely those attributable to hepatitis C virus (HCV), human immunodeficiency virus (HIV) and Helicobacter pylori. Expert commentary: An underlying HCV or HIV infection should always be suspected in patients at risk who present with isolated thrombocytopenia. The eradication of Helicobacter pylori is advisable in infected patients with secondary immune thrombocytopenia, because this will increase the platelet count in a substantial number of cases, thus avoiding more aggressive and prolonged treatments.

Review article: the global emergence of Helicobacter pylori antibiotic resistance

BACKGROUND

Helicobacter pylori is one of the most prevalent global pathogens and can lead to gastrointestinal disease including peptic ulcers, gastric marginal zone lymphoma and gastric carcinoma.

AIM

To review recent trends in H. pylori antibiotic resistance rates, and to discuss diagnostics and treatment paradigms.

METHODS

A PubMed literature search using the following keywords: Helicobacter pylori, antibiotic resistance, clarithromycin, levofloxacin, metronidazole, prevalence, susceptibility testing.

RESULTS

The prevalence of bacterial antibiotic resistance is regionally variable and appears to be markedly increasing with time in many countries. Concordantly, the antimicrobial eradication rate of H. pylori has been declining globally. In particular, clarithromycin resistance has been rapidly increasing in many countries over the past decade, with rates as high as approximately 30% in Japan and Italy, 50% in China and 40% in Turkey; whereas resistance rates are much lower in Sweden and Taiwan, at approximately 15%; there are limited data in the USA. Other antibiotics show similar trends, although less pronounced.

CONCLUSIONS

Since the choice of empiric therapies should be predicated on accurate information regarding antibiotic resistance rates, there is a critical need for determination of current rates at a local scale, and perhaps in individual patients. Such information would not only guide selection of appropriate empiric antibiotic therapy but also inform the development of better methods to identify H. pylori antibiotic resistance at diagnosis. Patient-specific tailoring of effective antibiotic treatment strategies may lead to reduced treatment failures and less antibiotic resistance.

Analysis of the Relative Contribution of Phagocytosis, LC3-Associated Phagocytosis, and Canonical Autophagy During Helicobacter pylori Infection of Macrophages

BACKGROUND

Previous findings have suggested that Helicobacter pylori induces autophagic processes and subsequently takes refuge in autophagosomes, thereby contributing to persistent infection. Recently, a noncanonical form of autophagy, LC3 (microtubule-associated protein 1 light chain 3)-associated phagocytosis (LAP), has been shown to be required for efficient clearance of some intracellular bacteria. Whether H. pylori infection induces LAP had not been examined previously. In this study, we determined the extent to which H. pylori infection induces canonical autophagy or LAP in macrophages, and the involvement of the H. pylori cag pathogenicity island (cagPAI) with these processes.

METHODS

Immunofluorescence confocal microscopy was used to analyze the formation of GFP-LC3 puncta and their colocalization with H. pylori. Transmission electron microscopy was used to detect the ultrastructure of H. pylori-containing compartments.

RESULTS

The majority of intracellular bacteria (85-95%) were found in phagosomes that were LC3-negative, with a small proportion (4-14%) appearing "free" in the cytosol. Only a very small percentage (0.5-6%) of intracellular H. pylori was sequestered in autophagosomes. Furthermore, no statistically significant difference in the relative distribution of H. pylori in the various compartments was observed between wild-type and cagPAI-mutant bacteria.

CONCLUSIONS

In macrophages, H. pylori infection does not induce LAP, but can induce canonical autophagy, which entraps a very small fraction of intracellular bacteria. We propose that this subpopulation of intracellular H. pylori might have escaped from phagosomes into the cytosol before being sequestered by autophagosomes. The cagPAI of H. pylori has only minor influence, if any, on the extent of these processes.

Expansion of the tetracycline-dependent regulation toolbox for Helicobacter pylori

In an effort to gain greater understanding of the biology and infection processes of Helicobacter pylori, we have expanded the functionality of the tetracycline-dependent gene regulation (tet) system to provide more improved and versatile genetic control and facilitate the generation of conditional mutants to study essential genes. Second-generation tetracycline-responsive H. pylori uPtetO5 promoters were based on the mutated core ureA promoter. Single point mutations at either the ribosomal binding site or the start codon were introduced to shift the regulatory range of three uPtetO5 derivatives. All promoters were tested for regulation by TetR and revTetR using dapD, a gene essential to peptidoglycan biosynthesis, as a reporter. All tet promoters were effectively regulated by both TetR and revTetR, and their regulation windows overlapped so as to cover a broad range of expression levels. tet promoters uPtetO5m1 and uPtetO5m2 could be sufficiently silenced by both TetR and revTetR so that the conditional mutants could not grow in the absence of diaminopimelic acid (DAP). Furthermore, through the use of these inducible promoters, we reveal that insufficient DAP biosynthesis results in viable cells with altered morphology. Overall, the development and optimization of tet regulation for H. pylori will not only permit the study of essential genes but also facilitate investigations into gene dosage effects on H. pylori physiology.

Epigenetic regulation of DNA repair machinery in Helicobacter pylori-induced gastric carcinogenesis

Although thousands of DNA damaging events occur in each cell every day, efficient DNA repair pathways have evolved to counteract them. The DNA repair machinery plays a key role in maintaining genomic stability by avoiding the maintenance of mutations. The DNA repair enzymes continuously monitor the chromosomes to correct any damage that is caused by exogenous and endogenous mutagens. If DNA damage in proliferating cells is not repaired because of an inadequate expression of DNA repair genes, it might increase the risk of cancer. In addition to mutations, which can be either inherited or somatically acquired, epigenetic silencing of DNA repair genes has been associated with carcinogenesis. Gastric cancer represents the second highest cause of cancer mortality worldwide. The disease develops from the accumulation of several genetic and epigenetic changes during the lifetime. Among the risk factors, Helicobacter pylori (H. pylori) infection is considered the main driving factor to gastric cancer development. Thus, in this review, we summarize the current knowledge of the role of H. pylori infection on the epigenetic regulation of DNA repair machinery in gastric carcinogenesis.

The diagnosis and treatment of Helicobacter pylori infection in Arctic regions with a high prevalence of infection: Expert Commentary

Helicobacter pylori infection is a major cause of peptic ulcer and is also associated with chronic gastritis, mucosa-associated lymphoid tissue (MALT) lymphoma, and adenocarcinoma of the stomach. Guidelines have been developed in the United States and Europe (areas with low prevalence) for the diagnosis and management of this infection, including the recommendation to ‘test and treat’ those with dyspepsia. A group of international experts performed a targeted literature review and formulated an expert opinion for evidenced-based benefits and harms for screening and treatment of H. pylori in high-prevalence countries. They concluded that in Arctic countries where H. pylori prevalence exceeds 60%, treatment of persons with H. pylori infection should be limited only to instances where there is strong evidence of direct benefit in reduction of morbidity and mortality, associated peptic ulcer disease and MALT lymphoma and that the test-and-treat strategy may not be beneficial for those with dyspepsia.

Helicobacter pylori neutrophil-activating protein: a potential Treg modulator suppressing allergic asthma?

The ultimate aim of the immune system is to eliminate pathogens without being harmful to the host. But what if eliminating the pathogen in itself is discomforting for the host? One such emerging case is of Helicobacter pylori. Modern medicine, infantile vaccination, and ultra-hygienic conditions have led to progressive disappearance of H. pylori in different parts of the world. However, the adversities caused by H. pylori's absence are much larger than those caused by its presence. Asthma is rising as an epidemic in last few decades and several reports suggest an inverse-relationship between H. pylori's persistence and early-life onset asthma. Regulatory T cells play an important role in both the cases. This is further supported by experiments on mouse-models. Hence, need of the hour is to discern the relationship between H. pylori and its host and eliminating its negative impacts without disturbing our indigenous microbiota. To resolve whether H. pylori is a pathogen or an amphibiont is another important side. This review explores the biological basis of H. pylori-induced priming of immune system offering resistance to childhood-onset asthma. HP-NAP-Tregs interaction has been predicted using molecular docking and dynamic simulation.

Etiopathogenesis of peptic ulcer: back to the past?

OBJECTIVES

To review some aspects of the etiopathogenesis of peptic ulcerous disease especially on the basis of studies on its correlation with Helicobacter pylori (H. pylori).

METHODS

A search was made in the data bases MEDLINE, LILACS and PubMed, and in Brazilian and foreign books, referring to the incidence and prevalence of infection by H. pylori and of peptic ulcerous disease in various populations of different countries.

RESULTS

It was observed that the prevalence of H. pylori infection is similar in individuals with peptic ulcerous disease and the general population. There are differences between countries with respect to the prevalence of infection and of gastric or duodenal peptic ulcers. In many countries the prevalence of infection by H. pylori shows stability while the prevalence of peptic ulcerous disease is declining. The prevalence of peptic ulcerous disease without H. pylori infection varies between 20% and 56% in occidental countries.

DISCUSSION

The observations might be suggestive of H. pylori being only one more factor to be summed together with other aggressive components in the genesis of peptic ulcerous disease. We would therewith be returning to the classic concept that peptic gastric and duodenal ulcers have multifactorial etiology and would result from imbalance between aggressive and defensive factors. The focus of studies should be enriched with the identification of the defensive factors and of other aggressive factors besides the well known H. pylori and non-steroidal anti-inflammatory drugs, since these two aggressors do not exhaust the full causal spectrum.

Environmental risk factors associated with Helicobacter pylori seroprevalence in the United States: a cross-sectional analysis of NHANES data

Helicobacter pylori imparts a considerable burden to public health. Infections are mainly acquired in childhood and can lead to chronic diseases, including gastric ulcers and cancer. The bacterium subsists in water, but the environment's role in transmission remains poorly understood. The nationally representative National Health and Nutrition Examination Survey (NHANES) was examined for environmental risk factors associated with H. pylori seroprevalence. Data from 1999–2000 were examined and weighted to represent the US population. Multivariable logistic regression estimated adjusted odds ratios (aOR) and 95% confidence intervals (CI) for associations with seropositivity. Self-reported general health condition was inversely associated with seropositivity. Of participants aged <20 years, seropositivity was significantly associated with having a well as the source of home tap water (aOR 1·7, 95% CI 1·1–2·6) and living in a more crowded home (aOR 2·3, 95% CI 1·5–3·7). Of adults aged ⩾20 years, seropositivity was not associated with well water or crowded living conditions, but adults in soil-related occupations had significantly higher odds of seropositivity compared to those in non-soil-related occupations (aOR 1·9, 95% CI 1·2–2·9). Exposures to both well water and occupationally related soil increased the effect size of adults' odds of seropositivity compared to non-exposed adults (aOR 2·7, 95% CI 1·3-5·6). Environmental exposures (well-water usage and occupational contact with soil) play a role in H. pylori transmission. A disproportionate burden of infection is associated with poor health and crowded living conditions, but risks vary by age and race/ethnicity. These findings could help inform interventions to reduce the burden of infections in the United States.

Probiotic and technological properties of Lactobacillus spp. strains from the human stomach in the search for potential candidates against gastric microbial dysbiosis

This work characterizes a set of lactobacilli strains isolated from the stomach of healthy humans that might serve as probiotic cultures. Ten different strains were recognized by rep-PCR and PFGE fingerprinting among 19 isolates from gastric biopsies and stomach juice samples. These strains belonged to five species, Lactobacillus gasseri (3), Lactobacillus reuteri (2), Lactobacillus vaginalis (2), Lactobacillus fermentum (2) and Lactobacillus casei (1). All ten strains were subjected to a series of in vitro tests to assess their functional and technological properties, including acid resistance, bile tolerance, adhesion to epithelial gastric cells, production of antimicrobial compounds, inhibition of Helicobacter pylori, antioxidative activity, antibiotic resistance, carbohydrate fermentation, glycosidic activities, and ability to grow in milk. As expected, given their origin, all strains showed good resistance to low pH (3.0), with small reductions in counts after 90 min exposition to this pH. Species- and strain-specific differences were detected in terms of the production of antimicrobials, antagonistic effects toward H. pylori, antioxidative activity and adhesion to gastric epithelial cells. None of the strains showed atypical resistance to a series of 16 antibiotics of clinical and veterinary importance. Two L. reuteri strains were deemed as the most appropriate candidates to be used as potential probiotics against microbial gastric disorders; these showed good survival under gastrointestinal conditions reproduced in vitro, along with strong anti-Helicobacter and antioxidative activities. The two L. reuteri strains further displayed appropriated technological traits for their inclusion as adjunct functional cultures in fermented dairy products.

Does Helicobacter pylori protect against eosinophilic esophagitis in children?

BACKGROUND

Helicobacter pylori infection and eosinophilic esophagitis (EoE) in children seem to have a reversed association with socioeconomic status (hygienic condition) and allergy conditions. While Hp infection (Hp) is highly associated with poor hygiene and/or poor socioeconomic status, but not with allergic conditions (asthma, rhinitis, etc.), EoE has the opposite epidemiological relationship (high association with allergy but low with low hygienic conditions).

AIM

To investigate the association between Hp infection and EoE in children.

METHODS

A retrospective chart review of all children who undergo the first upper endoscopy procedure in the gastroenterology clinic, between 2007 and 2012, was performed. Demographic, endoscopic and histological data were collected. The data was divided into 4 diagnostic groups: Hp infection, EoE, reflux esophagitis, and children who had normal histology. The relationship between Hp positive children and the other groups was performed.

RESULTS

A total of 966 charts were available for review. Esophagitis, idiopathic gastritis, EoE, and Hp infection were detected in 268 (28%), 480 (49%), 62 (6%), and 31 (3%) children, respectively. The mean age of the EoE group was significantly lower compared to all reference groups (p < .002), but no significant different was detected among the reference groups (gastritis, GERD, and Hp infection; p = 1.00). Simple logistic regression analysis using Hp infection as a predictor for EoE did not find a significant relationship between these two variables (p-value = .471, OR = 0.478, 95% CI 0.06-3.56). However, multivariable logistic regression analysis between EoE and the reference groups indicated a significant negative relationship between Hp infection and EoE (p-value = .023, adjusted OR = 0.096, 95%CI 0.013-0.72). Neither gastritis nor GER showed significant relationship with EoE (p-values are 1.000 and .992, respectively).

CONCLUSION

A reversed association between Hp and EoE was found in a cohort of West Virginia children. The possible explanations for these findings are discussed.

Prevalence of lesions detected at upper endoscopy: an Italian survey

BACKGROUND

Prevalence of gastroduodenal lesions is changing in the last decades. Prevalence of Helicobacter pylori infection, non-steroidal anti-inflammatory drugs (NSAIDs), and proton pump inhibitor (PPI) therapy may be involved in such a phenomenon. We assessed gastroduodenal lesions prevalence in a nationwide study.

MATERIALS AND METHODS

Consecutive patients who underwent upper endoscopy for the first time in 24 Italian centres between January 2012 and 31 March 2012 were enrolled. Prevalence of gastric ulcer (GU), duodenal ulcer (DU), gastric erosions (GE), duodenal erosions (DE), gastric polyp (GP), Barrett's oesophagus (BE), and neoplasia was assessed.

RESULTS

Overall, 1054 (M/F: 388/666; Mean age: 57.5 ± 5 years) patients were enrolled. H. pylori infection was detected in 356 (33.9%) patients, 358 (34%) were taking NSAIDs, and 532 (50.5%) PPIs. PPI therapy was associated with a significantly lower H. pylori detection rate (27.8% vs 39.8%; OR: 0.6, 95% CI 0.45-0.77; P<0.001). GU, DU, GE, DE, GP and BE were detected in 17 (1.6%), 13 (1.2%), 150 (14.2%), 50 (4.7%), 51 (4.8%) and 17 (1.6%), respectively. Moreover, 3 (0.3%) distal gastric cancers were observed. H. pylori infection remained the most prevalent factor for all gastroduodenal lesions, but gastric polyp. One third of patients with GU and GE were taking only NSAIDs therapy.

CONCLUSIONS

The prevalence of peptic ulcer was very low (<3%), with a similar rate between DU and GU. As many as half patients were on ongoing PPI therapy. Such a therapy could affect both the detection rate of H. pylori infection and the real prevalence of gastroduodenal lesions.

Helicobacter pylori infection in pregnant women in four districts of Uganda: role of geographic location, education and water sources

BACKGROUND

The prevalence of Helicobacter pylori infection varies in relation to geography, ethnicity and socioeconomic factors. Available data on the prevalence of Helicobacter pylori infection in Uganda are not representative of the general population. We sought to describe the epidemiology of this infection in pregnant women in Uganda to provide background data for a study into the effect of H. pylori infection during pregnancy on the hematological response to iron supplementation.

METHODS

Using a cross-sectional design, H. pylori infection was assessed by the stool antigen test among 447 pregnant women attending antenatal care clinics in Apac, Mbale, Mbarara and Rakai Districts which are in different geographical regions in Uganda, and at Kawempe Health Center which serves a low-income densely populated area in Kampala City. Socio-demographic and household data were collected by face-to-face interviews using a questionnaire. Associations between H. pylori infection and socio-demographic and household characteristics were analyzed using logistic regression.

RESULTS

The overall prevalence of H. pylori infection was 45.2% but varied by geographical location from 18.2% in Apac District to 60.5% at Kawempe Health Centre. At 18.4%, the Langi ethnic group, who were enrolled exclusively in Apac District, had the lowest prevalence of H. pylori infection while the Gisu had the highest prevalence (58.4%). H. pylori was independently associated with enrollment at clinics not in Apac (adjusted OR = 5.68; 95% CI: 3.02-10.7) and with using water from public wells, boreholes or springs (AOR = 3.20; 95% CI: 1.19-8.61) and from rivers, lakes or streams (AOR = 5.20; 95% CI: 1.58-17.05). Urban residence (AOR = 1.71; 95% CI: 1.13-2.60) and no formal education (AOR = 1.95; 95% CI: 1.03-3.67) were also independently associated with H. pylori infection.

CONCLUSIONS

The unexpected variation in the prevalence of H. pylori infection in Uganda calls for population-based studies in the region and offers an opportunity to study the transmission dynamics of H. pylori infection. The association between H. pylori infection and surface water sources for household use suggests waterborne transmission of H. pylori infection highlighting the need for concerted efforts in environmental health in communities and at the household level.

GenoType HelicoDR test in the determination of antimicrobial resistance of Helicobacter pylori in Korea

OBJECTIVE

Antimicrobial resistance of Helicobacter pylori is most important factor in eradication success. GenoType HelicoDR test has been developed for rapid detection of antimicrobial resistance. The present study evaluated the clinical usefulness of GenoType HelicoDR test in Korea.

MATERIALS AND METHODS

To detect 23S rRNA for clarithromycin resistance and gyrA mutations for fluoroquinolone resistance, both DNA sequencing after minimal inhibitory test (MIC) and GenoType HelicoDR test were performed in H. pylori isolates from the gastric mucosa of 101 patients. The eradication results of clarithromycin and moxifloxacin-containing triple therapy were evaluated by the 23S rRNA and gyrA mutations.

RESULTS

For 42 isolates with A2143G mutation by GenoType HelicoDR, 83.3% (35/42) of concordance rate was estimated with DNA sequencing method and 85.7% (36/42) for MIC test. For 43 isolates with N87K mutation by GenoType HelicoDR, 71.1% (31/43) of concordance rate was estimated with DNA sequencing and 88.4% (38/43) for MIC test. The sensitivity and specificity of GenoType HelicoDR test in determination of 23S rRNA mutation were 94.9% and 87.1%, and those of gyrA 98.2% and 80.0%. The sensitivity and specificity of GenoType HelicoDR test in determination of clarithromycin resistance based on MIC test were 55.0% and 80.0%, for fluoroquinolone 74.4% and 70.0%.

CONCLUSION

GenoType HelicoDR test is useful to determine mutations responsible for clarithromycin or fluoroquinolone-containing eradication failure but has a limitation for the clinical applicability in determination of resistance.

A comparison between 15-day sequential, 10-day sequential and proton pump inhibitor-based triple therapy for Helicobacter pylori infection in Korea

OBJECTIVE

The eradication rate of 10-day sequential therapy for Helicobacter pylori (H. pylori) infection was not satisfactory in Korea, probably due to antibiotic resistance. To compare the treatment efficacy of 15-day and 10-day sequential therapy of conventional 7-day proton pump inhibitor (PPI) triple therapy for the treatment of H. pylori infection.

METHODS

A total of 332 patients with H. pylori infection were randomly assigned to receive either 7-day PPI triple therapy, 10-day sequential therapy or 15-day sequential therapy. Eradication rate, drug compliance, and adverse events were compared among the three regimens.

RESULTS

The eradication rates by intention-to-treat analysis were 64.3% (95% CI: 55.5-73.2; 74 of 115 patients), 72.1% (95% CI: 63.6-80.5; 80 of 111 patients), and 80.2% (95% CI: 72.5-87.9; 85 of 106 patients) in the 7-day PPI triple, 10-day and 15-day sequential therapy groups, respectively (p = 0.032). The eradication rates by per-protocol analysis were 68.5% (95% CI: 59.6-77.4; 74 of 108 patients), 78.4% (95% CI: 70.3-86.5; 80 of 102 patients), and 89.5% (95% CI: 83.2-95.8; 85 of 95 patients) in the 7-day PPI triple, 10-day and 15-day sequential therapy groups, respectively (p = 0.001). There were no statistically significant differences between the three eradication therapy groups in regard to drug compliance and adverse events.

CONCLUSION

The 15-day sequential therapy demonstrated improved eradication efficacy compared with 7-day PPI triple and 10-day sequential therapy in Korea.

Reinfection after successful eradication of Helicobacter pylori in three different populations in Alaska

We performed a study to determine rates of reinfection in three groups followed for 2 years after successful treatment: American Indian/Alaska Native (AI/AN) persons living in urban (group 1) and rural (group 2) communities, and urban Alaska non-Native persons (group 3). We enrolled adults diagnosed with H. pylori infection based on a positive urea breath test (13C-UBT). After successful treatment was documented at 2 months, we tested each patient by 13C-UBT at 4, 6, 12 and 24 months. At each visit, participants were asked about medication use, illnesses and risk factors for reinfection. We followed 229 persons for 2 years or until they became reinfected. H. pylori reinfection occurred in 36 persons; cumulative reinfection rates were 14·5%, 22·1%, and 12·0% for groups 1, 2, and 3, respectively. Study participants who became reinfected were more likely to have peptic ulcer disease (P = 0·02), low education level (P = 0·04), or have a higher proportion of household members infected with H. pylori compared to participants who did not become reinfected (P = 0·03). Among all three groups, reinfection occurred at rates higher than those reported for other US populations (<5% at 2 years); rural AI/AN individuals appear to be at highest risk for reinfection.

Novel insights on the role of CD8+ T cells and cytotoxic responses during Helicobacter pylori infection

Helicobacter pylori chronically persists in 50% of the human population and causes serious gastric and duodenal pathologies in 15% of infected people. Research on the immune response to the infection has mainly focused on the induction of CD4+ T cell responses. Human studies emphasize the potential clinical relevance of CD8+ cytotoxic T lymphocytes, however this cell type has barely been reported in studies employing mouse or gerbil models. Traditionally characterized as an extracellular bacterium, H. pylori has been identified inside epithelial and immune cells. Similarly to other intracellular bacteria, H. pylori infection of macrophages can alter autophagy and phagosome processing. A novel animal model of H. pylori infection demonstrates for the first time the induction of cytotoxic CD8+ T cell responses in pigs and localization of intracellular H. pylori within lymphoid aggregates. Here, we discuss novel mechanisms of host-H. pylori interactions that could lead to the induction of cytotoxic responses.

Helicobacter pylori antibody patterns in Germany: a cross-sectional population study

BACKGROUND

Helicobacter pylori infection that is usually acquired in childhood and lasts for lifetime is mostly asymptomatic but associated with severe gastrointestinal disease including cancer. During chronic infection, the gastric mucosa is histologically changing. This forces H. pylori to permanent adaptation in its gastric habitat by expression of different proteins which might be reflected in distinctive antibody patterns.

METHODS

To characterize dynamics of the immune response to H. pylori we analysed 1797 sera of a cross-sectional study representative for the German population (age range 1-82 years) with multiplex serology, a fluorescent bead-based antibody binding assay that allows simultaneous and quantitative detection of antibodies. Fifteen recombinant, affinity-purified H. pylori proteins (UreA, GroEL, Catalase, NapA, CagA, CagM, Cagδ, HP0231, VacA, HpaA, Cad, HyuA, Omp, HcpC and HP0305) were used as antigens.

RESULTS

H. pylori seroprevalence (positivity for at least three antigens) was 48% and increased with age from 12% in children <15 years to 69% in females and 90% in males >65 years. Prevalences were highest (>83%) for Omp, VacA and GroEL. For 11 proteins, seroprevalence was higher in males than females (P < 0.05) from age 55 onwards. For all antigens, the median prevalence increase per age decade was stronger in males (8.4%, range 3.8-12.9%) than females (6.1%, range 3.4-10.8%). However, among seropositives the median number of antigens recognized increased from children <15 years to individuals >65 years stronger in females (P = 0.02). Antibody reactivities to GroEL, HyuA, CagM, Catalase, NapA and UreA also increased stronger in females (average 1.7-fold/decade, SD 0.5) than in males (1.5-fold/decade, SD 0.4).

CONCLUSION

H. pylori antibody response accumulates qualitatively and quantitatively with age. This may reflect a lifelong stimulation of the immune response by chronically active infection.