Epidemiology of Helicobacter pylori infection

Histomolecular profile of Helicobacter pylori strains circulating in Brazzaville (Congo)

Background and Aim

Helicobacter pylori (Hp) infection is a real public health problem in the Congo. We aimed study the histomolecular profile of Hp strains circulating in Brazzaville, Congo, in order to contribute to the improvement of Hp-infected patients in the country.

Methods

This was an analytical-transversal study carried out from January to November 2020 (i.e. a study period of 11 months) in the endoscopy centers of Brazzaville as well as the molecular biology and anatomopathology laboratories of Pointe-Noire and Oyo. It involved 100 symptomatic patients over the age of 18 referred for upper GI endoscopy. These patients underwent gastric biopsies for histopathological analysis according to the Sydney classification and molecular analysis using the real-time polymerase chain reaction (PCR) technique. The frequency of Hp infection was determined using real-time PCR. PCR was also used to identify the Hp strains and assess their tropism in the gastric mucosa. Digestive symptoms, endoscopic lesions, and histopathological lesions associated with HP infection were studied.

Results

The incidence of Hp infection was 91%, with a female predominance of 52.75% and an average age of 46.32 years. Endoscopy revealed normal mucosa (56.14%), ulcerated lesions (12.28%), and gastritis (22.81%) in infected patients. Histopathologically, the lesions were chronic atrophic gastritis (91%), with inflammatory activity (16.46%), intestinal metaplasia (16.46%), and adenocarcinoma (3.3%). Cag A strains were present in 85.71% of cases and had no preferential tropism in the gastric mucosa. Strains carrying the Cag A gene were present in severe and serious endoscopic and histopathological lesions.

Conclusion

The prevalence of Hp infection is 91% in the Brazzaville population. Cag A strains circulate in high proportions and are implicated in the occurrence of severe lesions of the gastric mucosa.

Structure-Based Virtual Screening of Helicobacter pylori SecA Inhibitors

The human bacterial pathogen Helicobacter pylori causes a range of gastric diseases. The killing rate of Helicobacter pylori is declining year by year because of high antibiotics resistance. It is urgent to develop new target and novel anti- Helicobacter pylori drugs. As an "energy pump" for bacterial cells, SecA is essential for bacterial growth and drives bacterial protein transmembrane transport, moreover SecA is absent in mammals, all of which nominate SecA as an attractive antimicrobial target. Here, we provided a structure-based virtual screening method to screen the 3D-diversity natural-product-like screening library against SecA for novel anti- Helicobacter pylori inhibitors with novel scaffolds. In this study, homology modeling was used to construct the three-dimensional structure of Helicobacter pylori SecA. Two rounds of molecular docking were then used to find new small-molecule inhibitors of SecA, identifying six lead candidates that maintained key interactions with the binding pocket. After that, molecular dynamics simulations were used to explore more accurate ligand-receptor binding modes in states close to natural conditions. Encouragingly, all six compounds were relatively stable during the simulation. Apart from that the binding free energy calculation based on MM/PBSA demonstrated favorable results of < -13.642 kcal/mol. Finally, ADME-T analysis indicated that these compounds were also sufficiently druggable. All six compounds can be well combined with the crystal structure, which further facilitate the development of SecA inhibitors and lead compounds against Helicobacter pylori.

The Association between Helicobacter Pylori Infection and Iron Deficiency Anemia in Children: A Systematic Review and Meta-Analysis

Objectives This study, comprising a systematic review and meta-analysis, was conducted to assess the association between Helicobacter pylori infection and the risk of iron deficiency anemia (IDA) in children.

Methods We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant published studies were searched in the databases. Retrieved studies were assessed for quality using the Modified Newcastle-Ottawa Scale for quality assessment. The “meta” package of statistical software “R 4.0.3 was used for statistical analysis.

Results Overall, 22 eligible studies (eight cross-sectional, six randomized control trials, five case-control, two surveys, and one cohort), including nine (40.9%) from Asia, four (18.1%) from America, four (18.1%) from Africa, four (18.1%) from Europe, and one (4.5%) from Australia with a total of 3,434 cases and 4,455 controls were included in this systematic review and meta-analysis. We found that H. pylori infection was associated with a high risk of IDA (odds ratio 1.70, 95% confidence interval 1.21 − 2.38) in a random-effects model. Meta-regression analysis showed that none of the investigated factors that may affect the prevalence of IDA reached statistical significance. There was statistically significant difference between results when studies were categorized according to the methods used to diagnose H. pylori and level of incomes based on World Bank classification. The GRADEpro Guideline Development Tool evidence for the risk of IDA was of a “moderate certainty.”

Conclusions This meta-analysis with a “moderate certainty” of evidence showed an association between H. pylori infection and a high risk of developing IDA in children.

Clinical relevance of virulence genes in Helicobacter pylori isolates recovered from adult dyspeptic patients in Turkey

PURPOSE

Bacterial virulence factors play a major role in the pathogenesis of Helicobacter pylori infection. The aims of this study were to evaluate virulence genes in H. pylori isolates and to compare the presence of these genes and associated clinical pathologies.

METHODS

A total of 148 H. pylori isolates, recovered from adult dyspeptic patients, were used. The patients, from whom the isolates were obtained, were assigned to two groups by their endoscopic findings, which manifested as chronic gastritis or peptic ulcer. The presence of gastric atrophy and intestinal metaplasia was recorded for each patient, based on histopathological examination. Analyses of the virulence genes were performed by the polymerase chain reaction technique.

RESULTS

The patients had a mean age of 47 ​± ​15 years and 86 (58%) of them were female. Based on endoscopic examination, 103 (69.6%) patients were diagnosed with chronic gastritis and 45 (30.4%) with peptic ulcer. Histopathological examination revealed intestinal metaplasia in 30 (20%) patients and gastric atrophy in 12 (8%) patients. The prevalence rates of cagA, cagE, iceA1, iceA2, and babA2 were determined to be 87%, 74%, 58%, 26%, and 95%, respectively. The most prevalent vacA alleles were s1/s1a (82%/97%) and the least prevalent allele was s2 (20%). A new vacA genotype (s1as1bs1c) was detected, for the first time, in 18 (12%) isolates. No significant difference was found between the patient groups with chronic gastritis and peptic ulcer for the prevalences of the virulence genes (p ​> ​0.05). Furthermore, intestinal metaplasia and gastric atrophy showed no significant correlation with the virulence genes (p ​> ​0.05).

CONCLUSIONS

It is thoughted that H. pylori isolates with predominant cagA, cagE, VacA (s1, s1a), and babA2 virulence genes are associated with gastroduodenal diseases. However, there is no correlation between gastric premalignant lesions and virulence genes.

Concurrence of Helicobacter pylori Infection and Its Associated Factors in Korean Couples

Background

This study evaluated the prevalence of Helicobacter pylori infection and the risk factors associated with H. pylori transmission among spouses.

Methods

We assessed the spousal concurrence of H. pylori infection using the Campylobacter-like organism (CLO) test under gastro-endoscopy in 132 couples. Based on the CLO test results, participants were categorized into H. pylori concurrent and independent groups. The chi-square test and Student t-test were performed for demographic comparisons between the concurrent and independent H. pylori groups. In addition, multivariate logistic regression analysis was performed to identify factors associated with concurrent H. pylori infection.

Results

The study revealed that the concurrence rate of H. pylori infection was 42.4% in married Korean couples. The odds ratio (OR) derived from the concurrence of H. pylori infection tended to decrease in older couples (OR, 0.975; 95% confidence interval [CI], 0.949-1.002; P=0.072). Gastric erosion was also associated with a decreased OR for concurrent infection (OR, 0.488; 95% CI, 0.295-0.808; P=0.005). Conversely, active duodenal ulcers were associated with an increased OR for concurrent infections (OR, 6.501; 95% CI, 1.267-33.346; P=0.025). Duodenal ulcer scars tended to increase the OR of concurrent infections (OR, 1.392; 95% CI, 0.815-2.380; P=0.226).

Conclusion

Spousal transmission and concurrence of H. pylori infection were negatively associated with gastric erosion; however, they were positively associated with active duodenal ulcers. Further studies are warranted to elucidate the mechanisms underlying these findings.

Detection of Helicobacter pylori by invasive tests in adult dyspeptic patients and antibacterial resistance to six antibiotics, including rifampicin in Turkey. Is clarithromycin resistance rate decreasing?

Background/aim

The prevalence of Helicobacter pylori is reported to be roughly 80% in Turkey, and only very few culture-based studies are available on antibacterial resistance in adult dyspeptic patients. This study was carried out in adult dyspeptic patients with an aim to: (i) detect H. pylori by invasive tests (culture, polymerase chain reaction, and histopathology) and (ii) determine the current resistance rates of H. pylori isolates to six antibiotics, including rifampicin.

Materials and methods

This study was conducted in 422 adult dyspeptic patients. The presence of H. pylori was demonstrated by culture, polymerase chain reaction, and the histopathology of gastric biopsy material. Antibacterial susceptibility was determined with the E-test.

Results

The mean age of the patients was 50 ± 15 (range 18–90), and 265 (63%) of them were female. By culture, polymerase chain reaction, and histopathology, the presence of H. pylori was detected at rates of 35% (148/422), 67% (281/422), and 53% (224/422), respectively. The prevalence of H. pylori was determined as 75.6% (319/422). Metronidazole, levofloxacin, clarithromycin, and rifampicin resistance rates were 62%, 36%, 19%, and 12%, respectively. Monodrug, dual-drug, and multidrug resistance rates were ascertained as 36.9%, 29.4%, and 10.5%, respectively. All of the isolates were susceptible to amoxicillin and tetracycline.

Conclusion

This study revealed the current prevalence of H. pylori in adult dyspeptic patients as 75.6%, and thereby, showed that infection with this pathogen remains highly prevalent. Although resistance to metronidazole and levofloxacin has increased over time, clarithromycin resistance rate has decreased. The high levels of resistance to metronidazole and levofloxacin limit the empirical use of these antibiotics in the eradication protocol. Owing to the low level of resistance determined for rifampicin, this antibiotic could be included in the eradication protocol, in the event of the need for rescue therapy in Turkey.

Nanomechanical Hallmarks of Helicobacter pylori Infection in Pediatric Patients

Background: the molecular mechanism of gastric cancer development related to Helicobacter pylori (H. pylori) infection has not been fully understood, and further studies are still needed. Information regarding nanomechanical aspects of pathophysiological events that occur during H. pylori infection can be crucial in the development of new prevention, treatment, and diagnostic measures against clinical consequences associated with H. pylori infection, including gastric ulcer, duodenal ulcer, and gastric cancer. Methods: in this study, we assessed mechanical properties of children’s healthy and H. pylori positive stomach tissues and the mechanical response of human gastric cells exposed to heat-treated H. pylori cells using atomic force microscopy (AFM NanoWizard 4 BioScience JPK Instruments Bruker). Elastic modulus (i.e., the Young’s modulus) was derived from the Hertz–Sneddon model applied to force-indentation curves. Human tissue samples were evaluated using rapid urease tests to identify H. pylori positive samples, and the presence of H. pylori cells in those samples was confirmed using immunohistopathological staining. Results and conclusion: collected data suggest that nanomechanical properties of infected tissue might be considered as markers indicated H. pylori presence since infected tissues are softer than uninfected ones. At the cellular level, this mechanical response is at least partially mediated by cell cytoskeleton remodeling indicating that gastric cells are able to tune their mechanical properties when subjected to the presence of H. pylori products. Persistent fluctuations of tissue mechanical properties in response to H. pylori infection might, in the long-term, promote induction of cancer development.

Helicobacter pylori infection and susceptibility to cardiac syndrome X: A systematic review and meta-analysis

BACKGROUND

Cardiac syndrome X (CSX) is characterized by persistent angina with normal coronary arteries. Several pathophysiologic mechanisms have been introduced, particularly Helicobacter pylori (H. pylori) infection.

AIM

To investigate the association between H. pylori infection and CSX.

METHODS

All studies related to H. pylori infection and CSX were evaluated by comprehensive searches of global databases such as ISI Web of Knowledge, PubMed, Scopus, EMBASE, and Google scholar. Statistical analyses of selected articles were evaluated based on the summary odds ratio (OR). Finally, heterogeneity and publication bias were estimated using the I² statistic and Cochrane Q-test as well as Begg’s and Egger’s tests.

RESULTS

A total of 11 studies met our inclusion criteria and 1435 patients (63% female, and 37% male) were reviewed. A significant association was observed between female patients and this syndrome (P = 0.02). Our results showed a positive association between infection with this pathogen and presence of CSX (OR: 5.65; 95% confidence interval [CI]: 4.17-7.64; I²: 82.20). However, no significant association was observed with cagA-positive H. pylori strains and this syndrome (OR: 0.97; 0.56-1.70 with 95%CI). Given the heterogeneity and publication bias, the results need to confirmed by further prospective investigation.

CONCLUSION

Based on our results, H. pylori infection is associated with an increased risk of CSX. This bacterium appears to play a major role in the pathogenesis of CXS by inducing persistent inflammation.

Management of bleeding peptic duodenal ulcer refractory to endoscopic treatment: surgery or transcatheter arterial embolization as first-line therapy? A retrospective single-center study and systematic review

BACKGROUND

The objective of this study was to compare the results of transcatheter arterial embolization (TAE) with surgery in terms of efficacy in the context of bleeding duodenal ulcer (BDU) refractory to endoscopic treatment.

MATERIALS AND METHODS

From January 2006 to December 2016, all patients treated for a BDU refractory to endoscopic treatment were included in this observational, comparative, retrospective, single-center study. Primary endpoint was the overall success of treatment of BDU requiring surgical and/or TAE. The secondary endpoints were pre-interventional data, recurrence rates, feasibility of secondary treatment, morbidity and mortality of surgical and radiological treatment, intensive care unit and length of stay. A systematic review of the literature was performed to compare results of surgery and TAE.

RESULTS

59 out of 396 patients (14.9%) treated for BDU required embolization and/or surgery: 15 patients underwent surgery (group S) including 7 patients after embolization failure and 44 patients underwent TAE (group TAE). The overall treatment success in intention to treat (85.7% vs 67.3%), per protocol (80% vs 79.5%) and bleeding recurrence rates (20% vs 15.9%) were also identical. Mortality (14.2% vs 15.3%) was similar between the two groups. Our study data were pooled with data from eight published studies and suggest that surgery have significant increased overall success (68.3% vs. 55.4%, p < 0.005).

CONCLUSION

The overall success rate was in favour of surgery according our meta-analysis. Our single-center study highlights the fact that predictive factors for recurrent bleeding after TAE must be identified to select good candidates for TAE and/or surgery.

Is the Utilization of Helicobacter pylori Stool Antigen Tests Appropriate in an Urban Canadian Population?

OBJECTIVES

Helicobacter pylori stool antigen test (HpSAT) appropriateness was investigated by assessing its testing and positivity rates in Calgary, Canada.

METHODS

The laboratory information system was accessed for all patients who received an HpSAT in 2018. Testing volume, test results, age, and sex of patients were collected. Sociodemographic risk factors and geospatial analysis were performed by matching laboratory data to the 2016 census data. Testing appropriateness was defined as a concordance between testing and positivity rates for each sociodemographic variable.

RESULTS

In 2018, 25,518 H pylori stool antigen tests were performed in Calgary, with an overall positivity rate of 14.7%. Geospatial mapping demonstrated significant distribution variations of testing and positivity rates of HpSAT in the city. Certain sociodemographic groups studied (eg, recent immigrants) appeared to be appropriately tested (testing rate relative risk [RR] = 2.26, positivity rate RR = 4.32; P < .0001), while other groups (eg, male) may have been undertested (testing rate RR = 0.85, positivity rate RR = 1.14; P < .0001).

CONCLUSIONS

Determining concordance of testing and positivity rate of a laboratory test can be used for assessing testing appropriateness for other diseases in other jurisdictions. This study demonstrated some at-risk patients may be missed for H pylori testing.

Relationship between African Biogeographical Ancestry and Helicobacter pylori infection in children of a large Latin American urban center

BACKGROUND AND AIM

The relationship between race/ethnicity and H pylori infection has been extensively reported, with a higher prevalence of infection observed in black individuals. Whether such differences are due to genetic factors underlying African ancestry remains to be clarified. In the present study, we evaluated the association between the proportion of individual African ancestry and H pylori infection in a sample of 1046 children living in a large Latin American urban center.

MATERIALS AND METHODS

Estimation of individual biogeographical ancestry was based on 370,539 SNPs and performed using the ADMIXTURE software. Multivariate logistic regression models and mediation analysis considering the influence of previously recognized socioenvironmental risk factors to H pylori infection were performed. All analyses were conducted using the statistical package STATA v.14.0.

RESULTS

Each 10% increase in the proportion of individual African ancestry was positively and independently associated with H pylori infection in our population (adjusted OR = 1.22, 95% CI = 1.10-1.36, P < .001). Mediation analysis demonstrated that only 9.23% of the effect of the individual African ancestry on H pylori infection was explained by factors such as household income, the absence of street paving and crowding.

CONCLUSIONS

The results suggest that genetic variants that covariate with African ancestry may explain an important part of the racial differences observed for the prevalence of H pylori infection.

Association between Active H. pylori Infection and Iron Deficiency Assessed by Serum Hepcidin Levels in School-Age Children

Hepcidin regulates iron metabolism. Its synthesis increases in infection and decreases in iron deficiency. The aim of this study was to evaluate the relationship between H. pylori infection and iron deficiency by levels of hepcidin in children. A total of 350 school-age children participated in this cross-sectional study. Determinations of serum ferritin, hemoglobin, hepcidin, C-reactive protein, and α-1-acid-glycoprotein were done. Active H. pylori infection was performed with a 13C-urea breath test. In schoolchildren without H. pylori infection, hepcidin was lower in those with iron deficiency compared to children with normal iron status (5.5 ng/mL vs. 8.2 ng/mL, p = 0.017); while in schoolchildren with H. pylori infection the levels of hepcidin tended to be higher, regardless of the iron nutritional status. Using multivariate analysis, the association between H. pylori infection and iron deficiency was different by hepcidin levels. The association between H. pylori and iron deficiency was not significant for lower values of hepcidin (Odds Ratio = 0.17; 95% Confidence Interval [CI] 0.02-1.44), while the same association was significant for higher values of hepcidin (OR = 2.84; CI 95% 1.32-6.09). This joint effect is reflected in the adjusted probabilities for iron deficiency: Individuals with H. pylori infection and higher levels of hepcidin had a probability of 0.24 (CI 95% 0.14-0.34) for iron deficiency, and this probability was 0.24 (CI 95% 0.14-0.33) in children without H. pylori infection and lower levels of hepcidin. In children with H. pylori infection and iron deficiency, the hepcidin synthesis is upregulated. The stimulus to the synthesis of hepcidin due to H. pylori infection is greater than the iron deficiency stimulus.

Association between Helicobacter pylori gastritis and dental diseases: A cross-sectional, hospital-based study in Eastern Saudi Arabia

BACKGROUND

There is inconsistent evidence about the association between Helicobacter pylori (H. pylori) and dental diseases with possible effect of environmental factors. The aims of the study were to assess (1) the association between gastric and oral H. pylori colonization and (2) the association between oral colonization of H. pylori and dental diseases.

METHODS

A cross-sectional study was conducted in King Fahad University hospital in Khobar, Eastern Saudi Arabia in 2017. Patients admitted to the Endoscopy Unit were recruited and clinically examined for plaque, decayed teeth (D), filled teeth (F), missing teeth (M), periodontal pocket depth (PPD), attachment loss (AL), and gingival bleeding in addition to assessing their age, gender, education, tooth brushing, flossing, and tobacco use with a questionnaire. Pooled dental plaque samples were collected and analyzed using nested polymerase chain reaction PCR to detect oral H. pylori. Gastroscopy was used to extract biopsies to assess gastritis and the presence of gastric H. pylori using Giemsa stain. Regression analysis was used to assess differences between patients with and without gastritis, oral H. pylori and gastric H. pylori in the percentage of sites with gingival bleeding, PPD, CAL, D, M, and F with adjustment for confounders.

RESULTS

One hundred twenty patients were included. Most of them brushed daily (82.6%) and had university education (45.7%). Of these, 34.2% had gastric H. pylori and 5% had oral H. pylori. No significant association was observed between the percentage of sites with gingival bleeding, mean PPD, AL, F, and either gastritis, the presence of oral or gastric H. pylori. Patients with gastritis had significantly higher number of D and M than patients without gastritis (P = 0.03).

CONCLUSIONS

In this study, the presence of gastric and oral H. pylori in patients with good oral hygiene and moderate socioeconomic status is not significantly associated with periodontal diseases. Patients with gastritis tend to have a higher number of decayed and missing teeth.

Helicobacter pylori Infection in Rural and Urban Dyspeptic Patients from Venezuela

The goal of this work was to assess the Helicobacter pylori prevalence in a rural mestizo population and compare it to an urban population from Venezuela. The study was performed in gastric juice samples of 71 dyspeptic patients from Caracas (urban) and 39 from Tucupita (rural), in the Orinoco Delta region. Helicobacter pylori was detected by amplification of 16S rRNA, glmM, and ureA genes in 55.0% patients from urban and 87.2% from rural populations. cagA was found positive in 51% and 62% urban and rural patients, respectively. Non-H. pylori Helicobacter species were not detected in the urban population, but was found in 7.7% of patients in the rural study site. Frequency values of the 16S rRNA, glmM, and ureA genes were higher in the rural population. The odds ratio for each gene was 15.18 for 16S rRNA, 2.34 for glmM, 2.89 for ureA, and 1.53 cagA, showing significant differences except for cagA when gene frequency was compared in both populations. These results demonstrate a higher frequency of H. pylori and gastric non-H. pylori Helicobacter infection in a rural mestizo population with low hygienic standards as compared with city dwellers, representing a potential risk for the development of gastroduodenal diseases.

Water-induced modulation of Helicobacter pylori virulence properties

While the influence of water in Helicobacter pylori culturability and membrane integrity has been extensively studied, there are little data concerning the effect of this environment on virulence properties. Therefore, we studied the culturability of water-exposed H. pylori and determined whether there was any relation with the bacterium’s ability to adhere, produce functional components of pathogenicity and induce inflammation and alterations in apoptosis in an experimental model of human gastric epithelial cells. H. pylori partially retained the ability to adhere to epithelial cells even after complete loss of culturability. However, the microorganism is no longer effective in eliciting in vitro host cell inflammation and apoptosis, possibly due to the non-functionality of the cag type IV secretion system. These H. pylori-induced host cell responses, which are lost along with culturability, are known to increase epithelial cell turnover and, consequently, could have a deleterious effect on the initial H. pylori colonisation process. The fact that adhesion is maintained by H. pylori to the detriment of other factors involved in later infection stages appears to point to a modulation of the physiology of the pathogen after water exposure and might provide the microorganism with the necessary means to, at least transiently, colonise the human stomach.

Improvement and optimization of the classical gastric biopsy culture technique for Helicobacter pylori diagnosis using trypsin

Helicobacter pylori infection represents a key factor in the aetiology of various gastrointestinal diseases. H. pylori infection diagnosis is generally achieved using both invasive (e.g. biopsy of the gastric epithelium) and non-invasive methods. Therefore, cultivation on a growth medium becomes complex. Trypsin is a proteinase enzyme that plays a role in an early stage of tissue digestion. In this study, we used trypsin in order to improve the diagnostic sensitivity of the H. pylori cultivation technique. We used 46 duplicate antrum biopsy specimens, divided into trypsin-treated and non-treated groups. The tissues were seeded on a selective H. pylori growth agar medium. We demonstrated that the classic H. pylori culture technique misses the growth of a large number of H. pylori colonies. Significantly more colonies were found in the trypsin-treated specimens group.

Immunology and vaccines and nanovaccines for Helicobacter pylori infection

Helicobacter pylori infection is very common worldwide and is an important cause of gastritis, peptic ulcer disease, gastric mucosa-associated lymphoid tissue lymphoma, and gastric adenocarcinoma. Since the eradication requires treatment with multidrug regimens, prevention of primary infection by a suitable vaccine is attractive. Developing vaccines on the spot when and where an infection is breaking out might be possible, thanks to engineered nanoparticles. In this review, the nature of the host immune response to H. pylori infection is considered. We explain recent candidate vaccines and prophylactic or therapeutic immunization strategies for use against H. pylori. We also describe identification of different types of immune responses that may be related to protection against H. pylori infection. Thus, it seems that there is still a strong need to clarify the main protective immune response against H. pylori.

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.

Culture-guided treatment approach for Helicobacter pylori infection: Review of the literature

The progressive loss of efficacy of standard eradication therapies has made the treatment of Helicobacter pylori (H. pylori) more challenging than ever. Endoscopic-guided antibiotic susceptibility testing had previously been suggested to guide treatment after failure of second-line therapies. However, its role has expanded over the years, in accordance with the current Maastricht Guidelines. Several authors have dealt with this topic, developing both efficacy trials and cost-effectiveness trials against resistant H. pylori infections as well as infections in naïve patients. However, results are not homogeneous enough to provide definite advice, because antibiotic resistance is not the only reason for treatment failure. Moreover, the culture-guided approach is surrounded by many practical issues, such as the availability of both endoscopy units and microbiology laboratories, and the need for a standard of quality that cannot be satisfied everywhere. Finally, pre-treatment susceptibility testing should be part - and not the only weapon - of a targeted, personalized strategy to overcome H. pylori infection.

Helicobacter pylori associated chronic gastritis, clinical syndromes, precancerous lesions, and pathogenesis of gastric cancer development

Helicobacter pylori (H. pylori) infection is well known to be associated with the development of precancerous lesions such as chronic atrophic gastritis (AG), or gastric intestinal metaplasia (GIM), and cancer. Various molecular alterations are identified not only in gastric cancer (GC) but also in precancerous lesions. H. pylori treatment seems to improve AG and GIM, but still remains controversial. In contrast, many studies, including meta-analysis, show that H. pylori eradication reduces GC. Molecular markers detected by genetic and epigenetic alterations related to carcinogenesis reverse following H. pylori eradication. This indicates that these changes may be an important factor in the identification of high risk patients for cancer development. Patients who underwent endoscopic treatment of GC are at high risk for development of metachronous GC. A randomized controlled trial from Japan concluded that prophylactic eradication of H. pylori after endoscopic resection should be used to prevent the development of metachronous GC, but recent retrospective studies did not show the tendency. Patients with precancerous lesions (molecular alterations) that do not reverse after H. pylori treatment, represent the "point of no return" and may be at high risk for the development of GC. Therefore, earlier H. pylori eradication should be considered for preventing GC development prior to the appearance of precancerous lesions.

Present and past Helicobacter pylori infection in Mexican school children

BACKGROUND

In developing countries, more than 50% of children have serological evidence of Helicobacter pylori infection. However, serological tests for H. pylori did not differentiate between active and past infection. The objectives of this study were to estimate the frequency of active and past H. pylori infection utilizing functional urea breath test (UBT) and serological tests and evaluate factors associated with the infection.

METHODS

A total of 675 school children, 6-13 years of age, participated. UBT was performed to detect active H. pylori infection. Blood samples were obtained to determine iron status and Immunoglobulin G (IgG) responses to the H. pylori whole-cell and to Cag A antigens by antigen-specific enzyme-linked immunosorbent assays. Weight, height, and sociodemographic characteristics were recorded.

RESULTS

A total of 37.9% (95% Confidence Intervals (CI): 34.2-41.6) of school children had active or past H. pylori infection; of them, 73.8% (CI95% 68.4-79.2) were carrying CagA-positive strain, 26.5% (CI95% 23.2-29.8) had active infection, and 11.4% (95%CI: 9.0-13.8) had evidence of past H. pylori infection. School children with iron deficiency and low height for age had higher risk of H. pylori infection: [OR to active or past infection was 2.30 (CI 95% 1.01-5.23) and to active infection it was 2.64 (CI 95% 1.09-6.44)] compared to school children with normal iron status and height for age or with normal iron status but low height for age or with iron deficiency and normal height for age.

CONCLUSIONS

The estimated prevalence of infection depends of the test utilized. Frequency of H. pylori infection and carrying CagA-positive strains was high in this population. Malnutrition was associated with active H. pylori infection.

Recent acquisition of Helicobacter pylori by Baka pygmies

Both anatomically modern humans and the gastric pathogen Helicobacter pylori originated in Africa, and both species have been associated for at least 100,000 years. Seven geographically distinct H. pylori populations exist, three of which are indigenous to Africa: hpAfrica1, hpAfrica2, and hpNEAfrica. The oldest and most divergent population, hpAfrica2, evolved within San hunter-gatherers, who represent one of the deepest branches of the human population tree. Anticipating the presence of ancient H. pylori lineages within all hunter-gatherer populations, we investigated the prevalence and population structure of H. pylori within Baka Pygmies in Cameroon. Gastric biopsies were obtained by esophagogastroduodenoscopy from 77 Baka from two geographically separated populations, and from 101 non-Baka individuals from neighboring agriculturalist populations, and subsequently cultured for H. pylori. Unexpectedly, Baka Pygmies showed a significantly lower H. pylori infection rate (20.8%) than non-Baka (80.2%). We generated multilocus haplotypes for each H. pylori isolate by DNA sequencing, but were not able to identify Baka-specific lineages, and most isolates in our sample were assigned to hpNEAfrica or hpAfrica1. The population hpNEAfrica, a marker for the expansion of the Nilo-Saharan language family, was divided into East African and Central West African subpopulations. Similarly, a new hpAfrica1 subpopulation, identified mainly among Cameroonians, supports eastern and western expansions of Bantu languages. An age-structured transmission model shows that the low H. pylori prevalence among Baka Pygmies is achievable within the timeframe of a few hundred years and suggests that demographic factors such as small population size and unusually low life expectancy can lead to the eradication of H. pylori from individual human populations. The Baka were thus either H. pylori-free or lost their ancient lineages during past demographic fluctuations. Using coalescent simulations and phylogenetic inference, we show that Baka almost certainly acquired their extant H. pylori through secondary contact with their agriculturalist neighbors.

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.

Association of Helicobacter pylori infection with the Lewis and ABO blood groups in dyspeptic patients

Background:

Helicobacter pylori infection is a basic risk factor for chronic gastritis, and gastric carcinoma. Based on some studies, the reason is binding of H. pylori to H and Le^b antigens in gastric mucosa. However, some other findings have not determined any association between the infection and these antigens. Because of this controversy and the fact that H. pylori infection and gastric adenocarcinoma are common diseases in Iran, the assessment of the association of H. pylori infection with these blood groups could be valuable.

Materials and Methods:

In a cross sectional study on 135 adult dyspeptic patients in Mashhad, Iran, from 2009 to 2010, H. pylori infection was evaluated by using the Heliprobe ¹⁴C-urea breath test and the ABO and Lewis blood group antigens were determined by the tube method. Association between the Lewis and ABO phenotypes with H. pylori infection were analysed by Fisher's exact test. A P ≤ 0.05 was considered to be significant.

Results:

68 (50.4%) patients were positive for H. pylori infection. The frequencies of the ABO, Lewis and secretion phenotypes were not significant in the infected and non-infected patients. We also did not find a significant association between Le^a and Le^b antigens and this infection.

Conclusion:

We could not establish a significant association between the Lewis, ABO and secretion phenotypes with H. pylori infection. Diversity of sequences of blood group antigen b-binding adhesion (babA gene) of H. pylori may be a reason why our findings are different from other studies in other geographic areas.

Seroepidemiology of Helicobacter pylori Infection in Tepehuanos Aged 15 Years and Older in Durango, Mexico

This study aimed to determine the seroepidemiology of Helicobacter pylori infection in Tepehuanos (an indigenous ethnic group living in rural Mexico). The prevalence of anti-Helicobacter pylori IgG antibodies was examined in 156 Tepehuanos in Durango State, Mexico, using an enzyme-linked immunoassay. In addition, sociodemographic, clinical, and behavioral characteristics of Tepehuanos associated with seropositivity were investigated. In total, 103 (66%) of the 156 participants (mean age 31.03  ±  16.71 years) had Helicobacter pylori IgG antibodies. Fifty-four (52.4%) of the 103 seropositive individuals had Helicobacter pylori IgG antibody levels higher than 100 U/mL. Males and females had comparable seroprevalence of Helicobacter pylori infection and Helicobacter pylori IgG antibody levels. The seroprevalence was significantly higher in women with pregnancies than those without this obstetric characteristic. Logistic regression showed that Helicobacter pylori infection was positively associated with low education (OR = 3.37; 95% CI: 1.13-10.00; P = 0.02) and laborer occupation (OR = 2.71; 95% CI: 1.14-6.42; P = 0.02). This is the first report of seroprevalence and contributing factors for Helicobacter pylori infection in Tepehuanos and of the association of Helicobacter pylori infection with laborer occupation. Results warrants further research.

Helicobacter pylori colonization critically depends on postprandial gastric conditions

The risk of Helicobacter pylori infection is highest in childhood, but the colonization process of the stomach mucosa is poorly understood. We used anesthetized Mongolian gerbils to study the initial stages of H. pylori colonization. Prandial and postprandial gastric conditions characteristic of humans of different ages were simulated. The fraction of bacteria that reached the deep mucus layer varied strongly with the modelled postprandial conditions. Colonization success was weak with fast gastric reacidification typical of adults. The efficiency of deep mucus entry was also low with a slow pH decrease as seen in pH profiles simulating the situation in babies. Initial colonization was most efficient under conditions simulating the postprandial reacidification and pepsin activation profiles in young children. In conclusion, initial H. pylori colonization depends on age-related gastric physiology, providing evidence from an in vivo infection model that suggests an explanation why the bacterium is predominantly acquired in early childhood.

Natural history of Helicobacter pylori infection in Mexican schoolchildren: incidence and spontaneous clearance

OBJECTIVES

The aim of the present study was to estimate the incidence and spontaneous clearance rate of Helicobacter pylori infection and the effect of some variables on these outcomes in schoolchildren.

METHODS

From May 2005 to December 2010, 718 schoolchildren enrolled in 3 public boarding schools in Mexico City participated in the follow-up. At the beginning of the study and every 6 months thereafter, breath samples were taken to detect H pylori infection; blood samples and anthropometric measurements were taken to evaluate nutritional status. Data on sociodemographic characteristics were collected.

RESULTS

The prevalence of H pylori infection was 38%. The incidence rate was 6.36%/year. Schoolchildren with anemia or iron deficiency at the beginning of the study (who received iron supplements) showed a higher infection acquisition rate than those with normal iron nutritional status, hazard ratio (HR) 12.52 (95% confidence interval [CI] 4.01%-39.12%), P < 0.001 and HR 2.05 (95% CI 1.09%-3.87%), P = 0.027, respectively. The spontaneous clearance rate of the infection was 4.74%/year. The spontaneous clearance rate was higher in children who had iron deficiency (who received iron supplements), HR 5.02 (95% CI 1.33%-18.99%), P = 0.017, compared with those with normal nutritional iron status. It was lower in schoolchildren with ≥ 2 siblings compared with schoolchildren with 1 or no siblings, HR 0.23 (95% CI 0.08%-0.63%), P = 0.004.

CONCLUSIONS

H pylori infection status is dynamic in schoolchildren. Variables related to health status and infection transmission, such as iron status and number of siblings, are important for the incidence and spontaneous clearance of H pylori infection.

'Test and treat' policy in dyspepsia: time for a reappraisal

The 'test and treat' policy is the recommended way to eradicate Helicobacter pylori in young patients with uninvestigated dyspepsia if the prevalence of H. pylori is high. India is considered to have a high prevalence of H. pylori. This observational study was conducted in order to discover the prevalence of H. pylori disease in uninvestigated dyspeptic patients, based on stool antigen test and immunoglobulin M (IgM) antibodies in the sera in order to ascertain the role of the 'test and treat' policy in this geographical area. Fifty patients (age <55 years) with uninvestigated dyspepsia presenting to surgery out-patient department of a tertiary teaching hospital in northern India were included in the study. Fifty healthy controls were also included. Dyspeptic patients with alarm symptoms were excluded from the study. Patients and controls were tested for IgM antibodies in their sera and H. pylori antigen in their stools. The positivity of the IgM antibody and H. pylori antigen in stools of the cases was 16% and 8%, respectively, while only 4% IgM positivity was found in the controls' samples. This study highlights the low prevalence of H. pylori in dyspeptic Indian patients. This indicates that initial proton pump therapy may be a better option than the 'test and treat' policy for young patients with uninvestigated dyspepsia.

The occupational risk of Helicobacter pylori infection among gastroenterologists and their assistants

BACKGROUND

Helicobacter pylori is a widely spread bacterium that mainly inhabits the gastric mucosa and can lead to serious illnesses such as peptic ulcer disease, gastric carcinoma and gastric MALT lymphoma. The oral-oral route seems to be the main transmission route. The fact that endoscopes are contaminated after being used to perform a gastroscopy leads one to question whether gastroenterologists and endoscopy nurses and assistants run a higher risk of infection.

METHODS

A systematic search for literature was conducted in the MEDLINE and EMBASE databases and further publications were found in reference lists of relevant articles. Epidemiological studies on the occupational exposure of endoscopy personnel were collected and their quality was assessed. Pooled effect estimates were identified in a meta-analysis.

RESULTS

Of the 24 studies included in the analysis, 15 were considered to be methodologically good. Of these 15 studies, eight single studies showed a statistically significant increased risk of infection for gastroenterologists, and five for their assistants. Meta-analysis across all methodologically good studies found a statistically significant risk of 1.6 (95%CI 1.3-2.0) for doctors. The pooled effect estimates also indicated a statistically significant risk of Helicobacter pylori infection (RR 1.4; 95%CI 1.1-1.8) for assistants too.When studies are stratified by medical and non-medical control groups, statistically significant risks can only be recognised in the comparison with non-medical controls.

CONCLUSIONS

In summary, our results demonstrated an increased risk of Helicobacter pylori infection among gastroenterological personnel. However, the choice of control group is important for making a valid assessment of occupational exposure risks.

Helicobacter pylori before and after the kidney transplantation

Renal disease is often accompanied by significant gastrointestinal symptoms, and Helicobacter pylori is related to these disorders. There is a paucity of data about the endoscopic findings of kidney recipients. HLA-class II genes have been repeatedly investigated for predisposition to H. pylori infection. The aim was to evaluate the H. pylori infection rate, study the relationship between HLA antigens and H. pylori, and assess the post-transplant gastrointestinal disorders. Data of 709 uraemic patients were collected for seroepidemiologic study; 58.7% of patients were male and the mean age was 45.1 years. The endoscopic results of 543 kidney transplant recipients were analysed; their mean age was 49.5 years and 56.9% were male. Of 709 patients, 49.37% were seropositive for H. pylori. Prevalence of H. pylori decreased strongly with the year of birth. Significant difference was observed in the occurrence of HLA-DR12 according to H. pylori serology. Twenty-nine per cent of endoscopies showed ulcer disease in the first 3 months, more frequent (p = 0.0014) than later. The presence of H. pylori was verified in 20.9% of cases, less than in the general, and in the uraemic population (p < 0.0001). There was no association between the presence of H. pylori and ulcer (p = 0.28). Steroid pulse treatment for rejection was not associated with more ulcers (p = 0.11).

Chronic gastritis associated with Helicobacter pylori in Mexican children: histopathological patterns

The objective of this study was to analyze the histopathological patterns of inflammation, distribution, severity, and degree of gastric mucosa of Helicobacter pylori (Hp)-infected children in Northern Mexico, as well as the correlation between colonization density and inflammation intensity. We carried out a cross-sectional study of gastric biopsies performed on children ranging from 2 to 17 years of age who underwent upper gastrointestinal endoscopy for diverse gastroduodenal disorders. This study includes only children who were found to be Hp carriers, with positive results for tests of Hp antigens in feces and in gastric biopsy studies. We studied 107 patients (age 8.2 ± 3.7 years). In 47.7% of patients, the density of Hp colonization was low; only 21.5% had a marked density. Mononuclear leukocyte infiltration showed a similar distribution. Thirty-seven percent of patients had follicular gastritis. An acute inflammatory response was absent in 65% and mild in 20.6% of patients. When inflammation was present, it was primarily located in the antrum (79%). There were no cases of intestinal metaplasia or atrophy. A link was found between Hp density and age, infiltration by mononuclear cells, the presence of follicular gastritis, and the level of neutrophil infiltration (P  =  0.001). Despite the high rates of Hp infection in the region, the histopathological findings in these children were mild and were limited primarily to the antral mucosa. These data indicate the need to study the behavior of this disease in children in diverse study populations to provide localized prevention and treatment strategies.

[Role of Helicobacter pylori infection in iron deficiency anemia]

Anemia induced by digestive diseases refers to anemia due to iron deficiency. Conventional gastrointestinal diagnostic workup fails to establish the cause of iron deficiency in about one third of patients. Abnormal iron absorption is increasingly recognized as an important cause of unexplained iron deficiency. The importance of coeliac disease as a possible cause of iron deficiency anemia refractory to oral iron treatment, without other manifestations of malabsorption syndrome, is increasingly being recognized. In addition, Helicobacter pylori (HP) has been implicated in several recent studies as a cause of iron deficiency anemia (IDA) refractory to oral iron treatment. Cure of previously refractory IDA by HP eradication provides strong evidence supporting a cause-and-effect relationship. In order to establish a cause-and-effect relationship between HP gastritis and IDA, prospective randomized studies comparing the effects of iron administration with or without H. pylorieradication are highly recommended.

Helicobacter pylori infection and systemic sclerosis-is there a link?

Over the last 20 years, increasing evidence has accumulated to implicate infectious agents in the etiology of systemic sclerosis (SSc) and Raynaud's phenomenon. Infection rates in patients with SSc compared with those in control populations do not provide clear support for any specific pathogen. However, increased antibody titers, a preponderance of specific strains in patients with SSc, and evidence of molecular mimicry inducing autoimmune responses suggest mechanisms by which infectious agents may contribute to the development and progression of SSc. Helicobacter pylori (H. pylori) has been associated with diseases such as autoimmune gastritis, Sjögren's syndrome, atherosclerosis, immune thrombocytopenia purpura, inflammatory bowel diseases and autoimmune pancreatitis, in each of which it seems to play a pathogenetic, but it has also been suggested that it may help to protect against the development of autoimmune gastritis, multiple sclerosis, systemic lupus erythemathosus and inflammatory bowel diseases. A systematic literature search was carried out in MEDLINE, EMBASE, Cochrane Library and ACR/EULAR meeting abstracts. We hypotheses that H. pylori infection might play a critical role in the pathogenesis of SSc. Here we review studies examining the potential involvement of H. pylori infection in SSc.

Exposure to Helicobacter pylori-positive siblings and persistence of Helicobacter pylori infection in early childhood

OBJECTIVES

Cross-sectional studies suggest that Helicobacter pylori may be transmitted between siblings. The present study aimed to estimate the effect of an H pylori-infected sibling on the establishment of a persistent H pylori infection.

MATERIALS AND METHODS

The authors used data collected from a Texas-Mexico border population from 1998 to 2005 (the "Pasitos Cohort Study"). Starting at age 6 months, H pylori and factors thought to be associated with H pylori were ascertained every 6 months for participants and their younger siblings. Hazard ratios were estimated from proportional hazards regression models with household-dependent modeling.

RESULTS

Persistent H pylori infection in older siblings always preceded persistent infection in younger siblings. After controlling for mother's H pylori status, breast-feeding, antibiotic use, and socioeconomic factors, a strong effect was estimated for persistent H pylori infection in an older sibling on persistent infection in a younger sibling (hazard ratio 7.6, 95% confidence interval 1.6-37], especially when the difference in the age of the siblings was less than or equal to 3 years (hazard ratio 16, 95% confidence interval 2.5-112).

CONCLUSIONS

These results suggest that when siblings are close in age, the older sibling may be an important source of H pylori transmission for younger siblings.

Accuracy of rapid urease test in diagnosing Helicobacter pylori infection in patients using NSAIDs

BACKGROUND/AIM

This study aimed to determine the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on the results of rapid urease test (RUT).

PATIENTS AND METHODS

The study evaluated 210 consecutive patients for the diagnosis of Helicobacter pylori (H. pylori) infection. They were divided into case and control groups based on history of NSAID use (n=70 each). Two biopsy specimens were collected from antrum and corpus of stomach during endoscopy and sent for rapid urease testing and histopathology. Sensitivity, specificity, and accuracy rate of RUT test were compared against histology.

RESULTS

The average age was 55.2+/-12.9 and 43.3+/-12.1 years in the case and control groups, respectively. Among NSAID users, RUT sensitivity, specificity and accuracy rate were all 100%. The sensitivity, specificity and accuracy rate of RUT in patients without history of NSAID use were 97.37, 98.57 and 98.14%, respectively. The overall sensitivity, specificity and accuracy rate of RUT were 98.57, 99.29, and 99.04%, respectively.

CONCLUSION

Our study shows that sensitivity, specificity and accuracy rate of RUT are not affected by NSAID use. Rapid urease test remains a reliable test for diagnosis of H. pylori in patients on NSAIDs.

The effect of mastic gum on Helicobacter pylori: a randomized pilot study

Our aim was to study the effect of pure mastic gum on Helicobacter pylori (H. pylori) eradication in patients suffering from an H. pylori infection Fifty two patients were randomized to receive either 350mg three times a day (tid) of pure mastic gum for 14 days (Group A), or 1,05g tid of pure mastic gum (Group B) for 14 days, or pantoprazole 20mg twice a day (bd) plus pure mastic gum 350mg tid for 14 days (Group C) or pantoprazole 20mg bd plus amoxicillin 1g bd plus clarithromycin 500mg bd for 10 days (Group D). All patients harboured H. pylori before entering the study and that was confirmed by a (13)C urea breath test (UBT). H. pylori eradication was tested by a UBT 5 weeks after completion of the eradication regime. Eradication of H. pylori was confirmed in 4/13 patients in Group A and in 5/13 in Grour B. No patient in Group C achieved eradication whereas 10/13 patients in Group D had a negative UBT. There were no statistically significant differences in mean UBT values in Groups A, B, C although there was a trend in Group A (p=0.08) and in Group B (p=0.064). The difference was significant in Group D (p=0.01). All patients tolerated mastic gum well and no serious adverse events were reported. Mastic gum has bactericidal activity on H. pylori in vivo.

Methylation status of CDH1 gene in samples of gastric mucous from brazilian patients with chronic gastritis infected by Helicobacter pylori

CONTEXT: Gastric cancer is one of the top list of cancer types that most leads to death in Brazil and worldwide. Helicobacter pylori(H. pylori) is a class I carcinogen and infect almost 90% of chronic gastritis patients. Some genotypes confer different virulent potential to H. pylori and can increase the risk of gastritis development. Methylation of CpG islands can inactivate tumor suppressor genes and therefore, it can be involved in the tumorigenic process. CDH1 is a tumor suppressor gene that encodes the E-cadherin protein, which is important in maintaining cell-cell contacts. The inactivation of this gene can increase the chance of metastasis. Promoter methylation of CDH1 at early steps of gastric carcinogenesis is not yet completely understood. OBJECTIVE: In this study, we investigated the methylation status of CDH1 in chronic gastritis samples and correlated it with the presence of H. pylori. METHODS: Sixty gastric mucosal biopsies were used in this study. The detection of H. pylori was performed with the PCR primers specific to urease C gene. H. pylori genotyping was performed by PCR to cagA and vacA (s and m region). The methylation status of these gene CDH1 was analyzed using methylation-specific polymerase chain reaction and direct sequencing of the PCR products was performed using primers methylated and unmethylated in both forward and reverse directions. RESULTS: H. pylori was detected in 90% of chronic gastritis samples; among these 33% were cagA positive and 100% vacA s1. The genotype vacA s2/m1 was not detected in any sample analyzed. Methylation of CDH1 was detected in 63.3% of chronic gastritis samples and 95% of them were also H. pylori-positive. CONCLUSION: This work suggests that CDH1 gene methylation and H. pylori infection are frequent events in samples from Brazilian patients with chronic gastritis and reinforces the correlation between H. pylori infection and CDH1 inactivation in early steps of gastric tumorigenesis.

Helicobacter pylori reinfection in Brazilian patients with peptic ulcer disease: a 5-year follow-up

BACKGROUND

The Helicobacter pylori reinfection seems to be higher in developing countries, than in developed ones. The aim of the study was to determine the annual recurrence rate of H. pylori, in Brazilian patients with peptic ulcer disease, in a 5-year follow-up.

METHODS

Patients, with peptic ulcer disease diagnosed by upper digestive endoscopy (UDE) and H. pylori infection verified by histological analysis, rapid urease test, polymerase chain reaction, and urea breath test (UBT), were treated for bacterial eradication. The cure of the infection was verified using the same tests, 3 months after. Clinical evaluation and UBT were performed after sixth and ninth month. After 1 year of follow-up, UBT and UDE were repeated. Up to the fifth year, patients were assessed twice a year and an UBT was performed annually. The patients included and all the reinfected were tested for 15 different genes of the H. pylori.

RESULTS

One hundred and forty-seven patients were followed: 19 for 1 year, eight for 2 years, four for 3 years, five for 4 years, and 98 for 5 years, totaling 557 patients/years. Recurrence did not occur in the first year. In the second year, two patients were reinfected; in the third, four patients; in the fourth, three patients; and in the fifth, one patient. The total of reinfected patients was 10. The annual reinfection rate was 1.8%.

CONCLUSION

Brazil presents a low prevalence of H. pylori reinfection, similar to the developed countries.

Variables influencing outcome of Helicobacter pylori eradication therapy in South China

BACKGROUND

Therapy combining a proton pump inhibitor (PPI), clarithromycin and either amoxicillin or metronidazole is widely recommended for first-line treatment for Helicobacter pylori infection. The purpose of this study was to examine the outcomes of PPI-containing triple therapy and identify factors influencing the cure rate of H. pylori infection in South China.

MATERIALS AND METHODS

H. pylori positive patients with different occupations from 25 hospitals in five provinces of South China were enrolled. They received a PPI, metronidazole and amoxicillin triple therapy for a week. H. pylori eradication was evaluated by (13)C-urea breath test 4 weeks after therapy. Association between H. pylori eradication with occupation, gender, age, educational level, and protocol compliance was evaluated by Logistic regression.

RESULTS

Six hundred and seventy-five were enrolled. The intention-to-treat and per-protocol analyses showed overall cure rates of 60% (95% CI = 56.3-63.7%) and 64.5% (95% CI = 60.7-68.3%), respectively. Multivariate logistic regression showed that occupation, gender and protocol compliance were positively associated with the eradication rate (p < .01). The cure rate for those who took 80% or more of the prescribed drugs was 64.5% (95% CI = 60.7-68.3%) versus 14.6% (95% CI = 6-29%, p < .001) for those who took less. Lower eradication rates were also observed in farmers and women.

CONCLUSIONS

The eradication rate with a PPI, metronidazole and amoxicillin triple therapy was unacceptably low in South China. These results suggest that studies of the eradication of H. pylori infection in China must take into account antibiotic resistance as well as patient occupation, gender, and protocol compliance. Gastric cancer and peptic ulcer disease are both important in China making methods to effectively and efficiently eradicate H. pylori a priority.

Lactobacillus salivarius modulates cytokine induction and virulence factor gene expression in Helicobacter pylori

Human infection by the gastric pathogen Helicobacter pylori is characterized by a robust immune response which rarely prevents persistent H. pylori colonization. Emerging evidence suggests that lactobacilli may reduce H. pylori infection rates and associated inflammation. In this study, we measured the ability of two model strains of Lactobacillus salivarius (UCC118 and UCC119) to modulate gastric epithelial cell chemokine responses to H. pylori infection. Pre-treatment of AGS cells with either L. salivarius strain significantly decreased interleukin-8 (IL-8) production upon exposure to H. pylori, but not in cells stimulated with TNF-alpha. The production of the chemokines CCL20 and IP-10 by AGS cells infected with H. pylori was also altered following pre-treatment with UCC118 and UCC119. We showed that a greater reduction in IL-8 production with UCC119 was due to the production of more acid by this strain. Furthermore, UV-killed cells of both lactobacillus strains were still able to reduce H. pylori-induced IL-8 in the absence of acid production, indicating the action of a second anti-inflammatory mechanism. This immunomodulatory activity was not dependent on adhesion to epithelial cells or bacteriocin production. Real-time RT-PCR analysis showed that expression of eight of twelve Cag pathogenicity island genes tested was downregulated by exposure to L. salivarius, but not by cells of four other lactobacillus species. CagA accumulated in H. pylori cells following exposure to L. salivarius presumably as a result of loss of functionality of the Cag secretion system. These data identified a new mechanism whereby some probiotic bacteria have a positive effect on H. pylori-associated inflammation without clearing the infection.