Helicobacter pylori reinfection with identical organisms: transmission by the patients' spouses

Advancement of Engineered Bacteria for Orally Delivered Therapeutics

The use of bacteria and their biotic components as therapeutics has shown great potential in the treatment of diseases. Orally delivered bacteria improve patient compliance compared with injection-administered bacteria and are considered the preferred mode. However, due to the harsh gastrointestinal environment, the viability and therapeutic efficacy of orally delivered bacteria are significantly reduced in vivo. In recent years, with the rapid development of synthetic biology and nanotechnology, bacteria and biotic components have been engineered to achieve directed genetic reprogramming for construction and precise spatiotemporal control in the gastrointestinal tract, which can improve viability and therapeutic efficiency. Herein, a state-of-the-art review on the current progress of engineered bacterial systems for oral delivery is provided. The different types of bacterial and biotic components for oral administration are first summarized. The engineering strategies of these bacteria and biotic components and their treatment of diseases are next systematically summarized. Finally, the current challenges and prospects of these bacterial therapeutics are highlighted that will contribute to the development of next-generation orally delivered bacteriotherapy.

Two Cases of Acute Gastric Mucosal Lesions Due to Helicobacter pylori Infection Confirmed to be Transient Infection

Two adult cases of acute gastric mucosal lesions (AGML) caused by Helicobacter pylori infection were confirmed by spontaneous eradication during the follow-up period. The clinical course of the initial infection by H. pylori in adults with AGML remains unclear, whether it is transient or progresses to a persistent infection. In these two reported cases, gastric biopsies at the time of the onset revealed the presence of H. pylori; however, serum H. pylori antibodies performed at the same time were negative. Retesting for H. pylori serum antibody, after six months in one and after two months in the other, was negative, confirming spontaneous eradication.

Low compliance to post-screening recommendations in a family-based Helicobacter pylori screening and treatment program: A prospective cohort study

BACKGROUND

Intra-family transmission is an important Helicobacter pylori (H. pylori) infection route. Family-based screening and treatment of H. pylori is a promising strategy. However, limited data are available on patient compliance with post-screening recommendations for such a strategy.

MATERIALS AND METHODS

A prospective cohort study of families from six regions in Shandong, China, from July 2021 to February 2022 was conducted. Demographic characteristics, prior testing, and treatment for H. pylori, prior gastroscopy, symptoms, and family history were collected. Infection status of participants was determined using the ¹³ C-urea breath test. Infected participants were recommended to undergo eradication treatment, confirmation testing, and gastroscopy per expert consensus. Participants were monitored for 6 months to record recommendation compliance in a real-world setting. Logistic regression models were used to analyze the factors influencing compliance with the recommendations.

RESULTS

The study included 1173 individuals from 386 families with the overall infection rate of 36.7%. The recommendation compliance for eradication treatment, confirmation testing, and gastroscopy was 69.3% (271/391), 32.5% (88/271), and 6.1% (19/309), respectively. Factors that increased the risk of lower compliance were male sex (odds ratio [OR], 1.917, 95% confidence interval [CI], 1.233-2.981), and living in a non-urban area (OR, 1.954, 95% CI, 1.241-3.074), for treatment recommendations; having more than one infected family member (OR, 2.138, 95% CI, 1.237-3.698), and a lower family income (¥100,000-¥300,000 per year, OR, 7.247, 95% CI, 1.788-29.363; or <¥100,000 per year, OR, 7.294, 95% CI, 1.832-29.042), for confirmation testing recommendations; and being asymptomatic (OR, 3.009, 95% CI, 1.105-8.196), for gastroscopy recommendations.

CONCLUSIONS

Post-screening recommendation compliance for this family-based H. pylori screening and treatment program was unsatisfactory. Further studies focusing on pre-screening education are warranted to improve compliance.

Helicobacter pylori acquisition rates and the associated risk factors amongst newlywed couples; a prospective cohort study in Tehran, Iran

BACKGROUND

The rates and routes of Helicobacter pylori transmission, in a high prevalent country like Iran, with gastric cancer as the leading cause of male cancer mortality is of essence. Here, we have studied the H. pylori-associated risk factors and the likelihood of interspousal transmission.

METHODS

In a cohort of 686 young prewed couples, questionnaires were self-administered and serum samples were collected, for assessment of risk factors and sero-status of H. pylori, at baseline and follow-up. Of the 475 H. pylori single- or double-seronegative couples, 201 returned for follow-up. The average follow-up duration was 2.2 (SD 0.6) years, with a total of 560.1 person-years. Logistic regression and Cox regression models were used to estimate the odds ratios (ORs) and hazard ratios (HRs).

RESULTS

The risk of infection was higher in men than women (OR:1.3, 95%CI:1.0-1.8) and among metropolitan than rural residents (OR=1.4, 95%CI:1.1-1.9). The risk of infection was significantly higher among those with three siblings (OR=1.6, 95%CI:1.1-2.2), and four or more siblings (OR=1.4, 95%CI:1.0-1.9), in reference to those with one or no siblings. H. pylori acquisition occurred in 10.9% (27/247) of the H. pylori seronegative participants. The risk of acquisition was significantly higher in older aged (HR=1.2, 95%CI: 1.1-1.3) and higher educated (HR=0.2, 95%CI:0.1-0.9) participants, than younger and illiterate subjects, respectively. Our analysis did not find any evidence for interspousal transmission (HR=1.0, 95%CI: 0.4-2.2).

CONCLUSION

Although we detected H. pylori acquisition in the young adult Iranian population, our findings did not support interspousal transmission, as a mode of adult H. pylori aquisition.

Effect of metformin on the eradication of H.Pylori infection in 25 -75 years old patients referring Loghman Hakim Hospital

Background

Various ways of treating H.pylori infection are reported, such as triple-therapy and quadruple therapy for two weeks. Some side effects have been seen during these treatments, besides Helicobacter pylori becoming resistant to these antibiotics easily. According to some studies, there is a relationship between metformin and reduction in Helicobacter pylori infection. Thus, in this study, we determine the effects of metformin on Helicobacter pylori infection.

Methods

We performed this assessment in a randomized, case-controlled way in the diagnosis of Helicobacter pylori infected outpatients and inpatients. In both groups (case group and control group), patients took two tablets for a two-week period. In the case group, the patients were given two metformin tablets (each containing 500mg of metformin (extended release) and in the control group, they were given two placebo tablets (each containing 500mg of white flour). We took h.pylori Ag stool test and rapid urease test to confirm the presence of Helicobacter pylori infection.

Results

In this study, at first all the patients had positive h.pylori Ag stool test or positive rapid urease test. At the end of this study, the results of h.pylori Ag stool*- test presented that Helicobacter pylori infection was negative in 82.7% of the case group patients and 76% of control group patients which illustrates suppression of Helicobacter pylori infection. However, comparing to the control group (P=0.36), this difference was not statistically remarkable.

Conclusion

According to these findings, it is stated that having metformin along with prescribed antibiotics can help decrease Helicobacter pylori infection.

Helicobacter pylori infection and eradication outcomes among Vietnamese patients in the same households: Findings from a non-randomized study

Objective

Familial transmission can possibly influence the infection and treatment of Helicobacter pylori. This study aimed to describe the prevalence of H. pylori infection and outcomes of eradication treatment among Vietnamese patients who live in the same households.

Methods

We conducted a prospective cohort study of Vietnamese household members with upper gastrointestinal complaints. Participants received esophagogastroduodenoscopy and H. pylori testing. The H. pylori-positive patients were treated and asked to return for follow-up within 4 months. To explore factors associated with H. pylori infection at baseline, we performed multilevel logistic regression to account for the clustering effect of living in the same households. To explore factors associated with eradication failure, we used Poisson regression with robust variance estimation to estimate the risk ratio.

Results

The prevalence of H. pylori infection was 83.5% and highest among children <12 years old (92.2%) in 1,272 patients from 482 households. There were variations in H. pylori infection across households (intraclass correlation = 0.14, 95% confidence interval (CI) 0.05, 0.33). Children aged <12 years had higher odds of H. pylori infection (odds ratio = 3.41, 95%CI 2.11, 5.50). At follow-up, H. pylori was eradicated in 264 of 341 patients (77.4%). The risk of eradication failure was lower for the sequential regimen with tetracycline.

Conclusion

H. pylori infection was common among people living in the same households. Eradication success for H. pylori was higher for the tetracycline sequential regimen. More research should be focused on how family factors influence H. pylori infection and on eradication treatment.

The Role of Helicobacter pylori Proinflammatory Outer Membrane Protein and Propolis in Immunomodulation on U937 Macrophage Cell Model

Background

Regarding the important role of proinflammatory outer membrane protein (OipA) in the pathogenesis of Helicobacter pylori infection and immunomodulatory activity of propolis, we aimed to evaluate the immunogenicity effect of a purified recombinant OipA protein and propolis in the induction of two cytokines, interferon-gamma (IFN-γ) and interleukin-4 (IL-4), in a macrophage cell model.

Materials and Methods

The recombinant protein used in the present study corresponding to the oipA expressing a 34-35 kDa protein. OipA protein was purified by Ni-NTA affinity chromatography. The purified OipA protein (2.5- 40 μg /mL) and the propolis ethanolic extract (5-40 μg/mL) were incubated with phorbol 12-myristate 13-acetate-treated human myelomonocytic cell line U937 cells. IL-4 and IFN-γ levels were measured after 48 hours of incubation using enzyme-linked immunosorbent assay.

Results

The amounts of IL-4 and IFN-γ were significantly increased. The optimum concentration of OipA for the secretion of IL-4 was 5 μg/ml (P<0.0001). At higher concentrations, the amount of IL-4 diminished until suppression at 40 μg/mL. The optimum concentration of propolis, resulting in the most significant increased secretion of both IL-4 and IFN-γ was 40 μg/mL (P=0.0001 and P=0.0004).

Conclusion

We found that an OipA concentration of 10 μg/mL was more effective for IFN-γ production; however, it was not effective for the high production of IL-4. Therefore, it is postulated that the OipA could mainly induce a Th1 response through the production of IFN-γ. We also observed propolis's capability to induce IFN-γ production; however, the effective concentration for this was the same as for IL-4. Therefore, as an adjuvant, proper concentration of propolis is required for OipA to give the optimum response.

Increased Reflux Esophagitis after Helicobacter pylori Eradication Therapy in Cases Undergoing Endoscopic Submucosal Dissection for Early Gastric Cancer

BACKGROUND

The role of Helicobacter pylori in the pathogenesis of reflux esophagitis is controversial. This study investigated the frequency of reflux esophagitis before and after H. pylori eradication in patients having endoscopic submucosal dissection for early gastric cancer.

METHODS

This study included 160 patients that fulfilled the study's criteria. Endoscopy was performed before and after H. pylori eradication, and reflux esophagitis was evaluated during the follow-up period.

RESULTS

Seropositivity for H. pylori in patients with early gastric cancer was 68.8%, 101 of them received eradication therapy. During the follow-up period, the incidence of reflux esophagitis increased from 3.1% to 18.8% in the successful eradication group but no case of reflux esophagitis was observed in the failed eradication group. The univariate and multivariate analyses showed a significant correlation between successful H. pylori eradication rate and the development of reflux esophagitis.

CONCLUSIONS

This study demonstrated that a successful H. pylori eradication therapy is a risk factor for newly developed reflux esophagitis in patients with endoscopic submucosal dissection for early gastric cancer.

Effect of Helicobacter pylori eradication on reflux esophagitis and GERD symptoms after endoscopic resection of gastric neoplasm: a single-center prospective study

Background

The association between Helicobacter pylori and reflux esophagitis (RE) remains controversial. This study aimed to prospectively evaluate the effect of H. pylori eradication on RE and gastroesophageal reflux (GERD) symptoms in H. pylori-positive patients who underwent endoscopic resection of gastric neoplasm.

Methods

Of the 244 patients enrolled in this study, 173 H. pylori-positive patients underwent follow-up at least once. We evaluated the prevalence of RE and GERD symptoms in these patients following H. pylori eradication.

Results

There were 75.7% (131/173), 78.6% (125/159), and 78.9% (105/133) subjects who were successfully eradicated after 6, 12, and 18–24 months, respectively. During the 2-year follow-up period, the eradication of H. pylori did not increase the incidence of RE (OR 0.93; 95% CI, 0.49–1.77, p = 0.828). H. pylori status was also not associated with the development of GERD symptoms (OR 1.12; 95% CI, 0.47–2.95, p = 0.721). In the univariate analysis for RE, present smoking history (OR 4.79; 95% CI 1.98–11.60, p = 0.001), present alcohol consumption history (OR 2.18; 95% CI 1.03–4.63, p = 0.041), and diabetes mellitus (OR 2.44; 95% CI 1.02–5.86, p = 0.045) were found to be associated with RE. Multivariate analysis showed that present smoking history (OR 4.54; 95% CI 1.84–11.02, p = 0.001) was a significant risk factor for RE.

Conclusions

H. pylori eradication did not increase the incidence of RE or GERD symptoms in patients who underwent endoscopic resection of gastric neoplasm.

Helicobacter pylori: A foodborne pathogen?

Helicobacter pylori (H. pylori) is an organism that is widespread in the human population and is sometimes responsible for some of the most common chronic clinical disorders of the upper gastrointestinal tract in humans, such as chronic-active gastritis, duodenal and gastric ulcer disease, low-grade B-cell mucosa associated lymphoid tissue lymphoma of the stomach, and gastric adenocarcinoma, which is the third leading cause of cancer death worldwide. The routes of infection have not yet been firmly established, and different routes of transmission have been suggested, although the most commonly accepted hypothesis is that infection takes place through the faecal-oral route and that contaminated water and foods might play an important role in transmission of the microorganism to humans. Furthermore, several authors have considered H. pylori to be a foodborne pathogen because of some of its microbiological and epidemiological characteristics. H. pylori has been detected in drinking water, seawater, vegetables and foods of animal origin. H. pylori survives in complex foodstuffs such as milk, vegetables and ready-to-eat foods. This review article presents an overview of the present knowledge on the microbiological aspects in terms of phenotypic characteristics and growth requirements of H. pylori, focusing on the potential role that foodstuffs and water may play in the transmission of the pathogen to humans and the methods successfully used for the detection of this microorganism in foodstuffs and water.

Presentation and Epidemiology of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is the most prevalent gastrointestinal disorder in the United States, and leads to substantial morbidity, though associated mortality is rare. The prevalence of GERD symptoms appeared to increase until 1999. Risk factors for complications of GERD include advanced age, male sex, white race, abdominal obesity, and tobacco use. Most patients with GERD present with heartburn and effortless regurgitation. Coexistent dysphagia is considered an alarm symptom, prompting evaluation. There is substantial overlap between symptoms of GERD and those of eosinophilic esophagitis, functional dyspepsia, and gastroparesis, posing a challenge for patient management.

Are the view of Helicobacter pylori colonized in the oral cavity an illusion?

Urea breath test (UBT), as a leading preferred non-invasive diagnostic technology, but may not be able to detect oral H. pylori. With negative results of UBT, the patient may have an oral infection. On the basis of the fact of success, eradication rate may increase by 21% in the 95% Cl range after the elimination of oral H. pylori, the author believes oral H. pylori does exist and the oral cavity is the second colonized site aside its primary site of the stomach. H. pylori migrated out of Africa along with its human host circa 60 000 years ago; they are not lives in stomach only. In this review article, evidence established in recent years studies with use more appropriate technology had been listed and discussed. The author considers the oral cavity is a black hole for H. pylori infection that significant effective on gastroenterology and another medical field. The role of the oral cavity as the source of H. pylori infection is so controvert in past years. It seems like a human being having a second-time face to discover H. pylori in the history.

Recurrence of Helicobacter pylori infection and the affecting factors: A follow-up study

OBJECTIVE

Recurrence of Helicobacter pylori (H. pylori) infection weakens the protective effect and long-term prognosis of eradication. With the widespread therapies, decreasing prevalence of H. pylori infection and improvement in living conditions, the recurrence of H. pylori infection may present with new features. We conducted this prospective, large-scale, multicenter follow-up study to determine the recurrence rate of H. pylori infection and its affecting factors.

METHODS

A total of 827 patients receiving successful H. pylori eradication in our previous randomized controlled trial were enrolled. ¹³ C-urea breath test (UBT) was repeated one year after the eradication therapy to determine its recurrence. Moreover, a questionnaire survey was performed to explore the potential factors affecting the recurrence.

RESULTS

A total of 743 patients completed ¹³ C-UBT (follow-up rate 89.8%), and the result was positive in 13 patients one year after eradication therapy, with an annual recurrence rate of 1.75% (95% confidence interval [CI] 0.81-2.69%). Six hundred and ninety-two patients (13 with recurrence and 679 without recurrence) returned their questionnaires, with a response rate of >80%. Multivariate analysis revealed that peptic ulcer (odds ratio [OR] 3.385, 95% CI 1.016-11.274), close contact with individuals having H. pylori infection (OR 4.231, 95% CI 1.201-14.911), and hospitalization (OR 9.302, 95% CI 2.441-35.440) were independent risk factors of H. pylori infection recurrence.

CONCLUSIONS

The recurrence of H. pylori infection one year after eradication therapy is low in urban population of China. Peptic ulcer, contact history with individuals having H. pylori infection and hospitalization are risk factors.

Intrafamilial, Preferentially Mother-to-Child and Intraspousal, Helicobacter pylori Infection in Japan Determined by Mutilocus Sequence Typing and Random Amplified Polymorphic DNA Fingerprinting

BACKGROUND

The infection route of Helicobacter pylori has been recognized to be mainly intrafamilial, preferentially mother-to-child, especially in developed countries. To determine the transmission route, we examined whether multilocus sequence typing (MLST) was useful for analysis of intrafamilial infection. The possibility of intraspousal infection was also evaluated.

MATERIALS AND METHODS

Clonal relationships between strains derived from 35 index Japanese pediatric patients, and their family members were analyzed by two genetic typing procedures, MLST and random amplified polymorphic DNA (RAPD) fingerprinting.

RESULTS

Mostly coincident results were obtained by MLST and RAPD. By MLST, the allele of loci in the isolates mostly matched between the index child and both the father and mother for 9 (25.7%) of the 35 patients, between the index child and the mother for 25 (60.0%) of the 35 patients.

CONCLUSIONS

MLST is useful for analyzing the infection route of H. pylori as a highly reproducible method. Intrafamilial, especially mother-to-children and sibling, infection is the dominant transmission route. Intraspousal infection is also thought to occur in about a quarter in the Japanese families.

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

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

Helicobacter pylori outer inflammatory protein DNA vaccine-loaded bacterial ghost enhances immune protective efficacy in C57BL/6 mice

Helicobacter pylori (H. pylori) infection is associated with incidents of gastrointestinal diseases in half of the human population. However, management of its infection remains a challenge. Hence, it is necessary to develop an efficient vaccine to fight against this pathogen. In the present study, a novel vaccine based on the production of attenuated Salmonella typhimurium bacterial ghost (SL7207-BG), delivering H. pylori outer inflammatory protein gene (oipA) encoded DNA vaccine was developed, and the efficiency was evaluated in C57BL/6 mice. Significant higher levels of IgG2a/IgG1 antibodies and IFN-γ/IL-4 cytokines were detected after mice were oral administered with oipA DNA vaccine loaded SL7207-BG, indicating that a mixed Th1/Th2 immune response was elicited. When challenged with infective doses H. pylori strain SS1, the ghost based vaccine was capable of reducing bacterium colonization in the vaccinated mice. In addition, codon-optimized oipA plasmid loaded SL7207-BG significantly eliminates H. pylori colonization density in mice model. Thus, it has been demonstrated that this novel bacterial ghost based DNA vaccine could be used as a promising vaccine candidate for the control of H. pylori infection.

Helicobacter pylori is not eradicated after triple therapy: a nested PCR based study

Detection of Helicobacter pylori after triple therapy is usually carried out by either rapid urease test (RUT), urea breath test (UBT), histology, bacterial isolation, and single round PCR or serological tests. In this study, antral biopsy specimens from 25 patients were tested for H. pylori by RUT, culture, histology, and nested PCR in their antral biopsy specimens before and after treatment. Three genes, namely, heat shock protein (hsp60), phosphoglucosamine mutase (ureC), and flagellar export ATP synthase (fliI) of H. pylori were targeted. Of the 25 antral biopsy specimens, the RUT, culture, histology, and nested PCR positivity dropped from 81.8% to 12%, 31% to 0%, 100 to 84%, and 100% to 92%, respectively, before and after therapy. Further, hsp60 specific amplicons from 23 out of 25 patients gave identical restriction pattern, while 6 fliI and 1 ureC specific amplicon produced different restriction pattern. Furthermore, variations in fliI gene sequences in H. pylori after treatment were also confirmed by sequencing and compared in silico. Nested PCR based detection of H. pylori is more sensitive method to detect H. pylori after therapy than culture, RUT, and histology. Further, this study suggests that H. pylori is not eradicated completely after triple therapy.

Epidemiology of gastroesophageal reflux disease

The prevalence of gastroesophageal reflux disease (GERD) symptoms increased approximately 50% until the mid-1990s, when it plateaued. The incidence of complications related to GERD including hospitalization, esophageal strictures, esophageal adenocarcinoma, and mortality also increased during that time period, but the increase in esophageal adenocarcinoma has since slowed, and the incidence of strictures has decreased since the mid-1990s. GERD is responsible for the greatest direct costs in the United States of any gastrointestinal disease, and most of those expenditures are for pharmacotherapy. Risk factors for GERD include obesity, poor diet, lack of physical activity, consumption of tobacco and alcohol, and respiratory diseases.

Evaluating the immune responses of mice to subcutaneous immunization with Helicobacter pylori urease B subunit

Background

Helicobacter pylori, a gram-negative bacterial pathogen that expresses a strong urease activity, is associated with the development of gastroduodenal disease. Urease B subunit, one of the two structural subunits of urease, was expressed in E. coli BL21 (DE3) strain. The objective of this study was to evaluate the effects of Helicobacter pylori urease B subunit on the immune responses in mice by subcutaneous immunization.

Methods

The mice were immunized and boosted with Helicobacter pylori urease B subunit antigen subcutaneously three times with 2-wk intervals between the immunizations and boosters. The mice in the control group were immunized with PBS. The adjuvant group received PBS containing complete/incomplete freund’s adjuvant identical to antigen group without Helicobacter pylori urease B subunit antigen. Four weeks after the final booster, all the mice were sacrificed. Blood was collected on d 0, 14, 28 and 56 before immunization, booster and sacrifice, respectively. Immediately after sacrifice, gastric liquid and spleen were collected for antibody and cytokine analyses.

Results

Urease B subunit increased the concentrations of serum and gastric anti-urease B antigen specific IgG, and the levels of interleukin-4 and interferon-γ in splenocytes of the mice (P < 0.05).

Conclusions

This study demonstrated that recombinant urease B subunit can induce systemic and local immune responses in mice by subcutaneous immunization, which might be used as the effective component of vaccine against Helicobacter pylori.

Association between Helicobacter pylori and Barrett's esophagus, erosive esophagitis, and gastroesophageal reflux symptoms

BACKGROUND & AIMS

Infection with Helicobacter pylori, particularly the cytotoxin-associated gene A (cagA)+ strain, is believed to protect against Barrett's esophagus, but it is not clear if it protects against gastroesophageal reflux disease (GERD). We aimed to determine whether H pylori infection is associated with GERD symptoms, erosive esophagitis, and Barrett's esophagus within the same cohort.

METHODS

We analyzed data from a case-control study of 533 men (ages, 50-79 y) who underwent colorectal cancer screening at 2 tertiary medical centers in Michigan between 2008 and 2011 and who also were recruited to undergo upper endoscopy. We assessed 80 additional men found to have Barrett's esophagus during clinically indicated upper-endoscopy examinations. Logistic regression was used to estimate the associations between serum antibodies against H pylori or cagA and GERD symptoms, esophagitis, and Barrett's esophagus, compared with randomly selected men undergoing colorectal cancer screens (n = 177).

RESULTS

H pylori infection was associated inversely with Barrett's esophagus (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.29-0.97), particularly the cagA+ strain (OR, 0.36; 95% CI, 0.14-0.90). There was a trend toward an inverse association with erosive esophagitis (H pylori OR, 0.63; 95% CI, 0.37-1.08; and cagA+ OR, 0.47; 95% CI, 0.21-1.03). However, GERD symptoms were not associated with H pylori infection (OR, 0.948; 95% CI, 0.548-1.64; and cagA+ OR, 0.967; 95% CI, 0.461-2.03).

CONCLUSIONS

Based on a case-control study, infection with H pylori, particularly the cagA+ strain, is associated inversely with Barrett's esophagus. We observed a trend toward an inverse association with esophagitis, but not with GERD symptoms.

Helicobacter pylori infection in India from a western perspective

Helicobacter pylori is a common bacterial infectious disease whose manifestations predominately affect the gastrointestinal tract. India is the prototypical developing country as far as H. pylori infection is concerned and more than 20 million Indians are estimated to suffer from peptic ulcer disease. Considering the high level of medical research and of the pharmaceutical industry, one would expect that India would be the source of much needed information regarding new therapies and approaches that remain effective in the presence of antimicrobial resistance, new methods to reliably prevent reinfection, and the development of therapeutic and preventive vaccines. Here we discuss H. pylori as a problem in India with an emphasis on H. pylori infection as a serious transmissible infectious disease. We discuss the pros and cons of eradication of H. pylori from the entire population and come down on the side of eradication. The available data from India regarding antimicrobial use and resistance as well as the effectiveness of various treatments are discussed. Rigorous ongoing studies to provide current regional antibiotic resistance patterns coupled with data concerning the success rate with different treatment regimens are needed to guide therapy. A systematic approach to identify reliably effective (e.g., 90% or greater treatment success) cost-effective regimens is suggested as well as details of regimens likely to be effective in India. H. pylori is just one of the health care problems faced in India, but one where all the resources are on hand to understand and solve it.

Reinfection rate of Helicobacter pylori after eradication treatment: a long-term prospective study in Japan

BACKGROUND

We previously reported that the reinfection rate with Helicobacter pylori in Japan was low despite a high prevalence of infection. In the present study, we extended our previous work to more accurately determine the reinfection rate.

METHODS

We enrolled 1625 patients (219 women and 1406 men, mean age 50.8 years) who had received H. pylori eradication therapy. After documentation of eradication, bacterial culture and urea breath test were carried out yearly. H. pylori strains were analyzed by using random amplification of polymorphic DNA fingerprinting.

RESULTS

A total of 1609 patients were followed for up to 12.5 years (mean 4.7 years); H. pylori became re-positive in 26 patients. In 13 of the 26 patients, H. pylori became positive at the first-year follow up. Stored H. pylori isolates were available for analysis from ten of the 13 patients; four of the isolates were genetically different from the initial strain, but the other six were identical to the initial strain. In the other 13 patients, H. pylori became positive at later follow up (mean 4.8 years; range 1.8-8.0 years). In all of the four of these patients whose isolates could be analyzed, the H. pylori strains were different from the initial strain. Assuming that reinfection occurred in the four patients positive for different strains of H. pylori at the first-year follow up and in the 13 positive at later follow up, the reinfection rate was 0.22% per year.

CONCLUSIONS

When probable recrudescence (H. pylori positivity with identical strains) was excluded, the reinfection rate of H. pylori in this Japanese population was very low, but we note that reinfection can occur over many years.

Studies of distribution and recurrence of Helicobacter spp. gastric mucosa of dogs after triple therapy

PURPOSE: To analyze the triple antimicrobial therapy in positive Helicobacter spp. dogs and to investigate recurrence. METHODS: A total of 20 dogs underwent endoscopy followed by gastric biopsy using the rapid urease test and histopathology stained with Giemsa. Ten animals were treated with triple therapy recommended for humans and divided into control and experimental group. The control group was kept in isolation while the experimental group was placed in contact with positive animals during 60 days. RESULTS: The prevalence of infection in animals in this experiment was 100%, and more frequent in the fundus and the gastric body. Therapy for 7 days using clarithromycin, amoxicillin and lansoprazole was effective in 100% of the animals. Recurrence of the infection in 80% of dogs in the experimental group, while the control group remained eradicated after 60 days. CONCLUSION: Crowded environments associated with close contact with dogs infected with helicobacter are a determinant for transmission of Helicobacter spp. between canines.

Effect of Helicobacter pylori infection on Barrett's esophagus and esophageal adenocarcinoma formation in a rat model of chronic gastroesophageal reflux

OBJECTIVES

To investigate the relationship between Helicobacter pylori infection and Barrett's esophagus (BE), a rat model of chronic gastroesophageal reflux with H. pylori infection was established and the degree of inflammation, incidence of BE and esophageal adenocarcinoma (EA) were evaluated.

METHODS

Eight-week-old male specific-pathogen-free SD rats were divided into five groups randomly: pseudo-operation group; esophagojejunum anastomosis (EJA) group; EJA with H. pylori infection group; EJA with H. pylori infection and celecoxib-treated group; EJA with celecoxib-treated group. Rats were kept for 30 weeks after surgery. Esophageal lesion was evaluated grossly and microscopically. The expression of COX-2 and CDX2 was determined by RT-PCR and immunohistochemistry staining. The level of PGE₂ was assessed by enzyme-linked immunosorbent assay.

RESULTS

Esophageal mucosal injury in the group of EJA with H. pylori infection was decreased than that in EJA group (p < .05). The incidence of BE and EA in rats undergoing EJA with H. pylori infection was increased than in rats undergoing EJA with no statistical difference. Celecoxib treatment decreased the incidence of EA in rats undergoing EJA with H. pylori infection (p < .05). The expression of CDX2 mRNA was decreased in rats with H. pylori infection or treated with celecoxib than in the rats of pseudo-operation group (p < .05). When compared with those in rats of pseudo-operation group, the expression of COX-2 mRNA and the level of PGE₂ were upregulated in rats undergoing EJA irrespective of H. pylori infection (p < .05) and downregulated in rats treated with celecoxib (p < .05). When H. pylori colonized in esophagus, the severity of inflammation and the incidence of BE and EA were increased significantly. Higher levels of COX-2 expression and PGE₂ were detected in rats with esophageal H. pylori colonization.

CONCLUSIONS

When H. pylori infect in stomach, it may reduce the severity of inflammation. However, when colonizes in esophagus, H. pylori increases the severity of esophageal inflammation and the incidence of BE and EA. Celecoxib administration attenuates the incidence of EA by inhibiting COX-2 expression.

Time Trends of Gastro-esophageal Reflux Disease (GERD) and Peptic Ulcer Disease (PUD) in Iran

BACKGROUND Epidemiology of diseases changes over time with changes in socio-economic status, culture and health care systems. Gastroesophageal reflux disease (GERD) and peptic ulcer disease (PUD) are among the diseases whose epidemiology has changed over the past few decades in the west. Studies addressing the trend of GERD and PUD occurrence in Iran are lacking. We aimed to look at the time trends of GERD and PUD in a referral endoscopy clinic in Tehran, Iran. METHODS All patients with dyspeptic symptoms who underwent upper GI endoscopy from 1993 to 2005 (inclusive) in a tertiary outpatient GI referral center in Tehran were enrolled. Erosive esophagitis (EE, used as a proxy for GERD as a whole), PUD, rapid urease test (RUT) status and demographic characteristics were recorded from the endoscopy reports according to the year the endoscopy was performed. RESULTS Over a period of 13 years, 8,029 endoscopic examinations were performed. The most common endoscopic diagnosis was EE that occurred in 4,808 patients (59.8%) followed by duodenal ulcer in 2,188 (27.3%) and gastric ulcer in 88 (1.1%). Over 13 years (1995-2005), the proportion of EE increased from 14.1% in 1993 to 75.1% in 2005 among dyspeptic patients in this referral clinic. The proportion of each grade of GERD according to the Los Angeles classification was as follows: GERD-A 76.0%, GERD-B 20.9%, GERD-C 2.8% and GERD-D 0.3%. RUT positivity decreased from 71.4% to 9.5% during the study period. CONCLUSION This study shows a remarkable increase in EE with a concomitant decrease in PUD and RUT positivity among dyspeptic patients in Tehran over a decade. This change in trend is important for future health care planning.

Antimicrobial therapy of peptic ulcers

It is now accepted that peptic ulcer disease, whether duodenal or gastric, is one manifestation of infection with the bacterium Helicobacter pylori. This realization has revolutionized the management of peptic ulcer disease and changed the dictum from no acid no ulcer, to no H. pylori, no ulcer. When confronted with a patient with peptic ulcer disease, the physician must now ask whether H. pylori infection is present and if so, attempt to cure it. The gastric milieu is a very difficult environment for effective antimicrobial therapy. Nevertheless, current multi-drug antimicrobial therapy can be expected to cure the infection in more than 80% of patients. Cure of the infection is associated with a very low rate of recurrence. The continued risk of serious disease or disease complications associated with treatment failure and the availability of the urea breath test to non-invasively assess the results of therapy suggest that post therapy assessment should be routine. Because H. pylori infection causes structural and functional damage to the stomach and is associated with a lifetime risk of peptic or gastric cancer of approximately 16 and 1%, respectively, the infection should be treated whenever it is diagnosed. This paper reviews the current approach to therapy of patients with H. pylori infection, the effective antimicrobial drug combinations end the factors that predict treatment failure. Emergence of antimicrobial resistance may soon undermine the effectiveness of current drug regimens and require pretreatment culture and sensitivity testing as well as development of new drugs and drug regimens.

Helicobacter pylori and gastroesophageal reflux disease: a review of this intriguing relationship

A possible association between gastroesophageal reflux disease (GERD) and Helicobacter pylori (H. pylori) infection has been the subject of study and debate in recent years. This review discusses the pathophysiological and immunological mechanisms implicated in this relationship. Although gastric secretion in the majority of H. pylori-infected individuals is unaltered, this review considers how the bacteria may interfere with gastric acid production and what role it may play in GERD. We also identify the epidemiological evidence that confirms that GERD develops after the infection has been eradicated. Lastly, we clarify how the host's immune response and bacterial virulence factors interfere with this relationship, explaining the highly conflicting results in the literature.

Review article: 'true' re-infection of Helicobacter pylori after successful eradication--worldwide annual rates, risk factors and clinical implications

BACKGROUND

The incidence of 'true' re-infection with Helicobacter pylori after successful eradication remains uncertain.

AIM

To determine the worldwide rates, risk factors and clinical implications of 'true' re-infection of Helicobacter pylori. 'True' re-infection of H. pylori is defined as the situation where tests for H. pylori infection, which were negative for 12 months after eradication, become positive again at a later stage.

RESULTS

Thirty six studies were identified through a literature search to be able to produce annual rates of 'true' re-infection, and data from 33 original articles were considered reliable and adequate in the further review. Generally, the reported rates varied from 0% to 23.4% in adults and from 1.9% to 9.6% in children. Most studies from developed countries reported rates of less than 1%, whereas relatively higher rates were reported in most of the developing countries. Small sample sizes included in the studies appeared to be associated with increased re-infection rates. Interfamilial transmission is the major cause of re-infection, although iatrogenic re-infection through contaminated endoscopic equipment has been reported.

CONCLUSION

Helicobacter pylori re-infection is not a concern in a clinical setting, especially in the developed world; however, caution must be exercised in most developing countries.

Helicobacter pylori eradication therapy on histologic change in the distal esophagus

BACKGROUND

Although cases of reflux esophagitis (RE) developing after treatment to eradicate Helicobacter pylori have been discussed in some detail, no reports are available concerning the histologic examination of RE both before and after eradication therapy.

MATERIALS AND METHODS

Sixty-one patients and 111 specimens were investigated using endoscopic and histologic techniques. The histologic findings including basal zone height, papillar height, Ki-67 labeling index, and COX-2 expression before and after treatment for H. pylori infection were compared with those in normal controls and patients with endoscopic RE.

RESULTS

Twelve months after eradication therapy, the incidence of newly developed endoscopic RE was 20% (5/25). Basal zone height and papillar height had increased at 1 month, but had returned to pretreatment levels after 12 months of eradication therapy. The Ki-67 labeling index was significantly increased 1 and 12 months after eradication therapy compared to values before treatment. COX-2 expression gradually increased after the treatment. The phenomena linked to esophagitis appeared after eradication therapy. However, the severity and extent of these signs were not so high after the treatment of H. pylori than those in patients with overt reflux esophagitis. Focusing on the patients with hiatal hernia, papillar height and Ki-67 labeling index increased significantly after eradication therapy, values being almost the same as those in the patients with endoscopic RE.

CONCLUSIONS

Hiatal hernia plays an important role in the possible occurrence of hidden RE after treatment for a H. pylori infection.

Long-term study of re-infection following successful eradication of Helicobacter pylori infection

BACKGROUND

'Re-infection' with Helicobacter pylori after eradication has been estimated to occur in 0-14% of patients, although most so-called 're-infections' occur within the first year following 'eradication' and many may actually be due to recrudescence of a temporarily suppressed infection.

AIM

To study the true re-infection rate, we have studied re-infection rates after eradication therapy by excluding the first year's data, minimizing the possible confounding effect of recrudescence.

METHODS

All patients tested for H. pylori infection following eradication therapy between 1987 and 2004 were evaluated. Testing was carried out by urea breath test and gastric biopsy. Patients were included if they were found to be negative for H. pylori infection by testing at least 1 year following eradication and underwent at least one further test for H. pylori.

RESULTS

1162 patients met the inclusion criteria with median post-eradication follow-up of 3 years (1.5-14) including 4668 tests; 3319 years of follow-up were analysed. Thirteen cases of re-infection occurred (re-infection rate 0.4% per year).

CONCLUSIONS

This large study of H. pylori re-infection avoided cases of recrudescence by excluding the first post-eradication year. True re-infection is probably less common than previously thought.

Is Helicobacter pylori a pathogenic agent of the cervix uteri?

BACKGROUND

Helicobacter pylori is a gram-negative, microaerophilic rod-shaped bacterium that lives beneath the gastric mucosal layers, on the surface of epithelial cells. Gastric infection with this organism causes inflammation of the gastric mucosa, which can lead to gastritis, duodenal or gastric ulcers and even in rare cases to gastric carcinoma or MALT lymphoma. Approximately 50% of the population of the entire world is believed to be infected with H. pylori, but the exact route of transmission is still uncertain. It has been speculated that the cervix, with its endocervical columnar epithelium and acidic mucous layer, might provide a suitable environment for H. pylori. H. pylori might be a pathogenic agent for cervical infection. In order to address this issue we studied H. pylori in the endocervical tissue.

METHODS

To investigate our hypothesis, we examined cervical tissue using PCR, culture, and Gram-stain. Thirty-three cervices from women who underwent total hysterectomy for noninvasive non-cervical benign uterine diseases were analyzed in this study. Twenty-one patients had cervicitis and 12 patients were included as controls.

RESULTS

Of the 29 patients studied, none showed evidence of H. pylori infection. H. pylori was not detected by PCR, histology, or culture.

CONCLUSIONS

We could not detect H. pylori in the cervix of patients with cervicitis. H. pylori-infected patients' cervices remain to be investigated, and a larger study is needed to draw firm conclusions.

Long-term follow-up after eradication of Helicobacter pylori with omeprazole, clarithromycin, and tinidazole (OCT regimen) in a Japanese population

BACKGROUND

The long-term benefit of Helicobacter pylori eradication treatment that includes metronidazole on peptic ulcer disease in Japan is unclear. We investigated the rate of H. pylori re-infection and ulcer relapse after H. pylori eradication.

MATERIALS AND METHODS

A total of 266 patients with endoscopically confirmed peptic ulcer disease and H. pylori infection were treated with triple therapy of omeprazole 40 mg (20 mg b.i.d.), clarithromycin 800 mg (400 mg b.i.d.), and tinidazole 1000 mg (500 mg b.i.d.) for 7 days. Endoscopy with gastric biopsy was performed before and 1 month, 6 months, 1.5 years, and 3.5 years after therapy. H. pylori status was determined by H. pylori culture, rapid urease test, and histopathology. 13C-urea breath test was done at 6 months after eradication therapy. Treatment was deemed successful when all tests were negative at 6 months after therapy by endoscopic biopsy.

RESULTS

Successful H. pylori eradication was achieved in 262/266 (98.5%) patients with peptic ulcer. Total relapse of peptic ulcer occurred in 8/262 (3%) patients after eradication, with 3/262 (1.1%) occurring within 1.5 years after treatment and 5/262 (1.9%) within 3.5 years. All relapsed patients were found to be H. pylori-positive at the time of relapse. Of the 262 patients who experienced eradication, 20 (7.6%) were subsequently re-infected, six (2.3%) within 1.5 years and 14 (5.3%) within 3.5 years.

CONCLUSION

Triple therapy with omeprazole, clarithromycin, and tinidazole (OCT) is useful for H. pylori eradication in Japan, but there is an appreciable re-infection rate in this population.

The recurrence of Helicobacter pylori infection: incidence and variables influencing it. A critical review

The rate of H. pylori recurrence after eradication of the microorganism seems to be relatively low, at least in developed countries, where the mean annual reinfection rate is of approximately 3% per patient-year of follow-up, although the risk of reinfection in some developing regions is considerably higher. Several findings suggest that recrudescence rather than reinfection is likely to be responsible for most cases of recurrence: (i) the recurrences decrease with time and decline sharply after the first year, and (ii) studies using molecular fingerprinting techniques (polymerase chain reaction [PCR]) confirm that the identified microorganisms (before and after therapy) are usually genetically identical. The lower the efficacy of an antibiotic therapy, the greater the likelihood that recurrence occur, again suggesting that in these cases temporary "clearance" has been achieved rather than true eradication. The value of the (13)C-urea breath test after treatment is higher in those patients who suffer a recurrence; therefore, selection of a lower cut-off value may be helpful to maintain the diagnostic accuracy of posttreatment breath test, and thus preventing recrudescences. The observation of a pattern of histological (active) gastritis without the concomitant finding of H. pylori must raise the suspicion of a diagnostic error. Some studies suggest that recurrence is relatively infrequent, even if the patient's spouse is H. pylori-positive, suggesting that the patient's partner does not act as a reservoir for the reinfection. However, other investigators achieve contrary results, although a common exogenous source of H. pylori (for both partner's infection and patient's reinfection) cannot be ruled out. The oral cavity may be a potential source for recrudescence of gastric infection after successful therapy. When peptic ulcer reappears (sometimes with bleeding recurrence) or gastric MALT (mucosa-associated lymphoid tissue) lymphoma relapses after previous H. pylori eradication, recolonization of the gastric mucosa by the organism has almost always occurred.

Indicaciones y consecuencias de la erradicación de Helicobacter pylori en la enfermedad por reflujo gastroesofágico

Several epidemiological data indicate that H. pylori infection prevalence in patients with gastroesophageal reflux disease (GERD) is lower than that reported in respective controls, which would suggest that the organism plays a protective role against this disease. On the other hand, most studies demonstrate that the presence of the infection in patients with GERD does not negatively affect the therapeutic efficacy of proton pump inhibitors (PPIs), and, in case of negatively influencing it, the effects are not clinically relevant and are easily controllable with standard antisecretory treatment. Therefore, the decision to administer H. pylori eradication treatment to a patient should not be influenced by the concomitant presence of GERD. In most cases, H. pylori eradication does not seem to induce GERD development, and it does not seem to worsen GERD when it was already present. Nevertheless, when the gastritis pattern is unknown before the antibiotic administration, the effect of H. pylori eradication on gastric acid secretion and the incidence of GERD is unpredictable. In the exceptional cases in which H. pylori eradication could have negative effects on GERD, its clinical relevance will be limited, and reflux symptoms or endoscopic esophagitis will favourably respond to the standard PPI antisecretory treatment. Therefore, again, when H. pylori eradication is indicated in a particular patient, the concomitant diagnosis of GERD should not change our attitude. Finally, is has recently been recommended to eradicate H. pylori infection in those patients with GERD needing long-term treatment with PPI, as some studies have reported that these drugs induce, in presence of the organism, an atrophic gastritis, with the consequent risk of gastric cancer. However, most of these studies have important methodological defects, and several authors have reported contrary results. In any case, the appearance in the gastric mucosa of clinically relevant lesions, such as intestinal metaplasia, dysplasia or adenocarcinoma, in patients treated with PPI for several years, has not yet been demonstrated, although this could simply be a problem of time. This question seems to be too controversial to be answered with the available data, and we should wait until new studies clarify this topic. In the meantime, as it occurs with any controversial indication, the decision of the doctor facing a patient infected by H. pylori and needing maintenance therapy with PPIs should be assessed on a case by case basis.

Long-term follow-up of Helicobacter pylori eradication therapy in Vietnam: reinfection and clinical outcome

AIM

To assess the long-term Helicobacter pylori reinfection rates, as well as the clinical outcome in peptic ulcer disease patients in Vietnam.

METHOD

At a 1-year evaluation of H. pylori eradication treatment in 226 peptic ulcer patients, long-term H. pylori status was assessed with serology and/or culture, peptic ulcer status by gastroscopy, and DNA-fingerprinting performed with random amplified polymorphic DNA and restriction fragment polymorphism.

RESULT

Follow-up was performed a mean 11 months after the post-treatment evaluation on day 30 after beginning of treatment. The overall reinfection rate was 23.5%, with 58.8% of the strains being identical to the pre-treatment isolates and 41.2% being different. Peptic ulcer was found in 22.9% of the reinfected patients and in 6.3% of the non-reinfected. At the long-term follow-up of successful eradication cases, 89.8% of the patients were free of peptic ulcer disease. The corresponding result was 58.7% in patients in whom H. pylori eradication failed.

CONCLUSION

Following successful H. pylori eradication, reinfection with H. pylori in patients in Vietnam was found to be higher than in industrialized countries but the long-term recurrence of peptic ulcer disease was still low. Helicobacter pylori eradication treatment is therefore of value also in developing countries as the rate of peptic ulcer disease was low at the 1-year follow-up.

Helicobacter pylori reinfection rate 3 years after successful eradication

BACKGROUND AND AIM

Helicobacter pylori (HP) infection is one of the most prevalent human infections and has been implicated as a predisposing factor in gastric cancer, chronic active gastritis, duodenal ulcer, gastric ulcer and gastric lymphoma. Reinfection after successful eradication is quite uncommon in adults. In the only study carried out in Iran, a reinfection rate of 19.1% after 1 year has been reported. We studied the rate of reinfection 3 years after successful HP eradication.

METHODS

All patients who had undergone HP eradication 3 years before the study and had successful eradication verified by a negative (14)C urea breath test (UBT) 1 year after eradication were invited to complete a questionnaire and undergo another UBT. In addition, spouses and the offspring of those testing positive were offered an UBT.

RESULTS

Ninety-eight patients were enrolled (49% male). Mean age was 44 +/- 13 years (range: 18-75 years). Twenty patients (20.4%) had a positive UBT. Epigastric burning (25%vs 69%) and pyrosis (50%vs 67%) were seen less commonly in those who were HP free at 3 years compared to those who tested positive for HP.

CONCLUSIONS

According to our data, in our region the HP reinfection rate is 20.4% 3 years after successful eradication.

Evaluation of randomly amplified polymorphic DNA and pulsed field gel electrophoresis techniques for molecular typing of Dermatophilus congolensis

This study aimed to evaluate molecular typing methods useful for standardization of strains in experimental work on dermatophilosis. Fifty Dermatophilus congolensis isolates, collected from sheep, cattle, horse and a deer, were analyzed by randomly amplified polymorphic DNA (RAPD) method using twenty-one different primers, and the results were compared with those obtained by typing with a pulsed field gel electrophoresis (PFGE) method using the restriction digest enzyme Sse8387I. The typeability, reproducibility and discriminatory power of RAPD and Sse8387I-PFGE typing were calculated. Both typing methods were highly reproducible. Of the two techniques, Sse8387I-PFGE was the least discriminating (Dice Index (DI), 0.663) and could not distinguish between epidemiologically related isolates, whereas RAPD showed an excellent discriminatory power (DI, 0.7694-0.9722). Overall, the degree of correlation between RAPD and PFGE typing was significantly high (r, 0.8822). We conclude that the DNA profiles generated by either RAPD or PFGE can be used to differentiate epidemiologically unrelated isolates. The results of this study strongly suggest that at least two independent primers are used for RAPD typing in order to improve its discriminatory power, and that PFGE is used for confirmation of RAPD results.

Oesophageal adenocarcinoma or gastric cancer with or without eradication of Helicobacter pylori infection in chronic atrophic gastritis patients: a hypothetical opinion from a systematic review

BACKGROUND

As chronic atrophic gastritis is a precancerous condition for gastric cancer and the eradication of Helicobacter pylori infection halts chronic gastritis, eradication of infection may prevent gastric cancer. However, as chronic atrophic gastritis is a risk factor for reflux oesophagitis after eradication of infection, the risk of oesophageal adenocarcinoma may also increase.

METHODS

We systematically reviewed papers and estimated the expected annual incidence of oesophageal or gastric cancer with and without eradication of H. pylori infection in patients with chronic atrophic gastritis.

RESULTS

The expected annual incidence of gastric cancer in patients with corpus atrophy with persistent infection was at least 5.8-fold higher than that for oesophageal adenocarcinoma after the eradication of infection at all ages. Even for patients with accompanying reflux oesophagitis or Barrett's oesophagus, the expected incidence of either gastric or oesophageal adenocarcinoma with persistent infection was higher than that of oesophageal adenocarcinoma after eradication of infection.

CONCLUSION

If eradication of infection lowers the incidence of gastric cancer, it should be recommended for patients with corpus atrophy at all ages irrespective of the presence of reflux oesophagitis or Barrett's oesophagus, especially in populations having a high prevalence of gastric cancer.

High prevalence of multiple strain colonization of Helicobacter pylori in Korean patients: DNA diversity among clinical isolates from the gastric corpus, antrum and duodenum

BACKGROUND

The aims of our study were to determine the correlation of the strain variation and degree of homogeneity of infecting Helicobacter pylori (H. pylori) with their disease outcomes, and the relevance of duodenal H. pylori expression of cagA and/or vacA gene to the development of duodenal ulcer in Korean patients.

METHODS

One hundred and twenty bacterial colonies isolated from different anatomical sites of the stomach and duodenum were used. The study population was consisted of 40 Korean patients, 21 with duodenal ulcer, 7 with gastric ulcer, 3 with combined gastric and duodenal ulcer, and 9 with chronic gastritis. Genomic characteristics of each strain were analyzed by random amplified polymorphic DNA (RAPD) fingerprinting. The cagA and vacA genes were detected by polymerase chain reaction (PCR).

RESULTS

PCR-based RAPD was proved to be a reliable method for the discrimination of individual bacterial genomic characteristics. Genomic fingerprinting showed a varying degree of inter- and intra-patient variation. Thirteen patients (32.5%) were colonized by a single strain throughout the corpus, antrum and duodenum, whereas the other 27 (67.5%) harbored multiple H. pylori strains. Thirty-six isolates (90.0%) each from the corpus and antrum, and 34 (85.0%) from the duodenum, expressed the cagA gene. The prevalence of duodenal H. pylori expression of the cagA gene was not different between patients with chronic gastritis and those with duodenal ulcer. All isolates were positive for both genes vacA s1 and vacA s1a.

CONCLUSION

These results suggested that many of the H. pylori-infected Korean patients were actually colonized with mixed populations of different H. pylori strains and that the prevalence of duodenal H. pylori expression of the cagA and/or vacA gene was not correlated with the development of duodenal ulcer in Korean patients.

Abnormal gastroesophageal flap valve is highly associated with endoscopic reflux esophagitis after Helicobacter pylori eradication

BACKGROUND

Whether or not eradicating Helicobacter pylori worsens reflux esophagitis remains controversial. We investigated the relationship between gastroesophageal flap valve grading and endoscopic reflux esophagitis (in patients with peptic ulcer and gastritis) before and after H. pylori eradication in a case controlled study. Whether endoscopic assessment of the gastroesophageal flap valve allows prediction of endoscopic reflux esophagitis development or exacerbation was also assessed.

MATERIALS AND METHODS

A total of 220 patients with peptic ulcer or chronic gastritis, who received H. pylori eradication therapy, were followed for at least 6 months (range, 6-34 months) for endoscopic changes. Another 88 age- and disease-matched H. pylori-positive controls, without eradication therapy, were also enrolled. Gastroesophageal flap valve grade (I-IV) was assessed using the Hill classification.

RESULTS

Endoscopic reflux esophagitis incidence was significantly (p < .01) higher in abnormal gastroesophageal flap valve (grades III and IV) than in normal gastroesophageal flap valve (grades I and II) cases in both H. pylori eradication and control groups. The rate of new endoscopic reflux esophagitis after eradication was significantly (p < .01) higher in the abnormal than in the normal gastroesophageal flap valve group (54.5% vs. 9.1%). By contrast, the endoscopic reflux esophagitis exacerbation rate in patients with endoscopic reflux esophagitis before eradication was low (4.5%) and endoscopic reflux esophagitis improvement was observed in 40.9% of these patients.

CONCLUSIONS

These results suggest gastroesophageal flap valve grading by endoscopy to be useful for predicting the risk of newly developing endoscopic reflux esophagitis after H. pylori eradication, in addition to predicting the presence of endoscopic reflux esophagitis.

Helicobacter pylori infection and reflux esophagitis in children with chronic asthma

BACKGROUND

Reflux esophagitis is uncommon in countries in which most people are colonized by H. pylori infection and is extremely rare in persons with reflux esophagitis, although esophagitis is detected in almost 50% of children with recurrent lower respiratory tract symptoms.

HYPOTHESIS

Failure to acquire H. pylori can enhance esophagitis risk in children with chronic asthma.

PATIENTS AND METHODS

Forty-two pediatric out-patients with chronic asthma (mean age 13.2 +/- 1.18 years, range 12-15 years, 23 boys and 19 girls) were included in the study. They had undergone endoscopy with gastric and esophageal biopsies for upper dyspeptic complaints. H. pylori positivity was confirmed by positive Giemsa staining. Esophagitis was diagnosed by standard histologic procedure (presence of intraepithelial leukocytes or basal cell hyperplasia).

RESULTS

H. pylori colonization was detected histologically in 22 of 42 patients (52.4%) enrolled in the study. Histology demonstrated that in asthmatic children with evidence of H. pylori infection esophagitis was a dramatically rare finding than in the patients without the infection (P < 0.001). It was an unexpected finding, that lung function parameters (FEF50, FEF75) were significantly lower in asthmatics infected with H. pylori (P < 0.05).

CONCLUSION

The present findings suggest inverse association between esophagitis and H. pylori in course of asthma in pediatric patients.

Placental acquisition of maternal specific IgG and Helicobacter pylori colonization in infancy

BACKGROUND

Colonization with Helicobacter pylori generally occurs in infancy, and the microorganism is often acquired from close family members. Rate of infant colonization may be affected by maternal immune status.

METHODS

To investigate the potential protective effect of anti-H. pylori immunoglobulin G (IgG) acquired via the placenta, 65 mothers and their infants were studied from the infant's birth for 1 year. Circulating IgG antibodies were measured by enzyme-linked immunosorbent assay (ELISA) in cord blood and every 8 weeks. Immunoblotting was performed on sera from infants with significant increases in IgG levels. Rate of infant H. pylori colonization was measured by 13C urea breath tests every 4 weeks from the age of 12 weeks.

RESULTS

Maternal and infant cord blood specific IgG levels were correlated (R2 =.747, p <.001). Infant H. pylori specific IgG fell 5-fold compared to maternal levels over the first 6 months of life, and rose subsequently in many cases, with the development of novel immunoblot patterns. There were no significant associations between the age at first positive urea breath test and maternal or infant cord specific H. pylori IgG levels.

CONCLUSIONS

Transplacentally acquired specific IgG antibody does not protect infants from colonization by H. pylori.

Active and inactive gastroesophageal reflux diseases related to Helicobacter pylori therapy

We systematically reviewed the literature on gastroesophageal reflux disease (GERD) related to Helicobacter pylori therapy, and classified the GERD according to various aspects. Preexisting GERD is active GERD before H. pylori therapy, and a substantial proportion of the GERD patients improve after successful H. pylori therapy. If the GERD does not persist or recur after cessation of acid-suppressive therapy combined with H. pylori therapy, it may have been cured (cured GERD). If it recurs, it may have been masked by acid-suppressive therapy and unmasked with cessation of the therapy (pharmacologically masked and unmasked GERD). Newly developed GERD after successful H. pylori therapy is a kind of unmasked GERD arising after cure of infection (de novo unmasked GERD). The possible mechanism of the improvement of cured GERD is normalized hyperacidity associated with an improved cytokine-somatostatin-gastrin system followed by normalized G-cell activity and parietal cell mass. Preexisting GERD is not a reason to avoid eradication therapy. De novo unmasked GERD develops in a substantial proportion of patients with cured infection. The possible mechanism is increased acid exposure in the esophagus due to gastric acid increase, which is caused by a loss of neutralizing effect by ammonia, normalized cytokine-acid suppression and improvement of corpus atrophy. De novo unmasked GERD is important because GERD is recurrent and may induce adenocarcinoma of the esophagus. However, it is expected that cure of infection lowers gastric cancer incidence. Eradication therapy is recommended irrespective of the possibility that de novo unmasked GERD may have a slight increase of the risk of esophageal adenocarcinoma.

Effect of Helicobacter pylori infection in Barrett's esophagus and the genesis of esophageal adenocarcinoma

The relation between Helicobacter pylori and gastroesophageal reflux disease is unclear. Recent reports have suggested a possible protective role for H. pylori, particularly in preventing the complications of gastroesophageal reflux disease (GERD). The purpose of this article is to present a brief overview of the recent literature regarding the role of H. pylori in the genesis of the complications of GERD, focusing on Barrett's esophagus and esophageal adenocarcinoma. The prevalence of H. pylori infection in the population of the West is around 40% and is not different in cohorts of patients with GERD. When the infection induces pangastritis or corpus-predominant gastritis, there may be concomitant reduced gastric acid secretion. Eradication of the bacteria in this subgroup of patients may enhance gastric acid secretion and provoke reflux symptoms. H. pylori organisms do not colonize the specialized intestinal metaplasia characteristic of Barrett's esophagus. H. pylori infection rates in gastric mucosa of patients with Barrett's esophagus occur at a similar or slightly lower frequency than is found in controls. Gastric infection with cagA-positive strains of H. pylori appears to be uncommon in patients with Barrett's esophagus. Furthermore, epidemiologic studies indicate that cagA-positive strains are protective against esophageal adenocarcinoma. Several investigators have proposed that the decreasing prevalence of H. pylori infection might be an important factor in the rising incidence of this tumor.

Long-term observation of reflux oesophagitis developing after Helicobacter pylori eradication therapy

BACKGROUND

Development of reflux oesophagitis after Helicobacter pylori eradication therapy has been reported, but the prognosis is not well known.

AIM

To evaluate the prognosis of patients with reflux oesophagitis that developed after eradication therapy by long-term observation.

METHODS

Forty-five patients who developed reflux oesophagitis after successful H. pylori eradication therapy were followed up prospectively. All 45 patients were followed up by endoscopy more than 3 years after onset of reflux oesophagitis (3-year follow-up group) and nine were followed up more than 5 years after onset (5-year follow-up group). Endoscopic observations were performed yearly or when upper gastrointestinal symptoms recurred. Reflux oesophagitis was graded according to the Los Angeles Classification System. Presence of gastro-oesophageal reflux symptoms and medication of proton pump inhibitors, H2-blockers or prokinetics were investigated at final endoscopy.

RESULTS

All patients were classified as grade A or B at initial endoscopy. At final observation, the grade of reflux oesophagitis improved in 35/45 (78.8%) patients from the 3-year follow-up group and 7/9 (78.8%) patients from the 5-year follow-up group. Reflux oesophagitis progressed from grade A to B in only four (8.9%) patients from the 3-year follow-up group and in no patients in the 5-year follow-up group. No patient progressed to grade C or D. Gastro-oesophageal reflux symptoms were seen in 12 patients (26.7%) from the 3-year follow-up group and four patients (44.4%) from the 5-year follow-up group. Among them, medication was needed continuously in only six (13.3%) and two (22.2%) patients, respectively.

CONCLUSIONS

Reflux oesophagitis, which develops after H. pylori eradication therapy, rarely becomes a long-term clinical problem among patients who complete therapy successfully.

Is the recurrence of Helicobacter pylori infection after eradication therapy resultant from recrudescence or reinfection, in Japan

BACKGROUND

Reinfection of Helicobacter pylori after eradication is rare in developed countries but most often occurs within 1 year. In the present study, we attempted to differentiate between reinfection and recrudescence of H. pylori strains between 6 months and 6 years after successful eradication in Japan, a country with a high prevalence of H. pylori infection.

MATERIALS AND METHODS

After successful eradication of H. pylori, 274 patients were followed up by endoscopy and urea breath test. In recurrent patients, H. pylori strains isolated initially and after recurrence were compared using PCR-based restriction fragment length polymorphism (RFLP) analysis.

RESULTS

Recurrence of H. pylori occurred in 15 of 274 patients (5.5%) at 6 months after eradication and the annual recurrence rate was 2.0% per patient year (between 1 and 6 years). PCR-based RFLP analysis of H. pylori strains isolated initially and after recurrence showed that 62.5% (at 6 months) and 100% (after 1 years) of bacteria were of different strains.

CONCLUSION

Reinfection of H. pylori was not as rare at 6 months after eradication as reported previously, and up to 6 years after eradication, the annual reinfection rate is 2.0% per patient year in Japan.