Epidemiology of Helicobacter pylori Infection

A Simplified Low-Dose 10-Day Quadruple Therapy with a Galenic Formulation of Bismuth Salicylate Is Highly Effective for Helicobacter pylori Eradication

BACKGROUND

Earlier studies have shown that a modified low-dose bismuth quadruple therapy given for 10 to 14 days is highly effective for the treatment of Helicobacter pylori infection in Sardinia. However, bismuth is not universally available.

AIM

We aimed to investigate the efficacy of a simplified low-dose 10-day quadruple therapy containing a galenic formulation of bismuth salicylate for H. pylori infection.

PATIENTS AND METHODS

Adult patients positive for H. pylori infection were assigned to a quadruple therapy containing a galenic formulation of bismuth salicylate (200 mg) plus tetracycline 500 mg, metronidazole 500 mg and rabeprazole 20 mg, given twice a day with the midday and evening meals for 10 days. A negative stool antigen test or 13C-Urea Breath Test defined successful eradication. Compliance and adverse events were recorded 30-40 days after the end of treatment.

RESULTS

In this open-label pilot study, 42 patients were enrolled (mean age 54.1 ± 12.0 years; 64% female). Among the study participants, 35 were naïve to H. pylori treatment. The treatment regimen was completed by 41 patients, with an overall success rate of 95.1%. More specifically, the eradication rate was 95.1% PP; 95% confidence interval (CI) = 86.6-100 and 92.9% by ITT; 95%CI = 85.1-100%, respectively. For naïve patients, the cure rate was 97.1%. Compliance was excellent. Side effects were absent or mild overall.

CONCLUSIONS

The modified low-dose 10-day quadruple therapy provided high eradication rates of H. pylori infection, despite the replacement of colloidal bismuth subcitrate with bismuth salicylate. In regions where bismuth is unavailable in the market, the galenic formulation should be a valid option.

Metagenomic Changes of Gut Microbiota following Treatment of Helicobacter pylori Infection with a Simplified Low-Dose Quadruple Therapy with Bismuth or Lactobacillus reuteri

Background: Probiotic supplementation to antibiotic regimens against Helicobacter pylori infection has been proposed to improve eradication rate and to decrease detrimental effects on gut microbiota. Aims: To evaluate microbiota modifications due to a low-dose quadruple therapy with bismuth or Lactobacillus reuteri. Methods: Forty-six patients infected with H. pylori were prospectively enrolled in a single-centre, randomized controlled trial to receive b.i.d. with meals for 10 days low-dose quadruple therapy consisting of rabeprazole 20 mg and bismuth (two capsules of Pylera® plus 250 mg each of tetracycline and metronidazole), or the same dose of rabeprazole and antibiotics plus Gastrus® (L. reuteri), one tablet twice-a-day for 27 days. Stool samples were collected at the enrolment, at the end and 30–40 days after the treatment. Gut microbiota composition was investigated with 16S rRNA gene sequencing. Results: Eradication rate was by ITT 78% in both groups, and by PP analysis 85.7% and 95.5% for Gastrus® and bismuth group, respectively. Alpha and beta diversity decreased at the end of treatment and was associated with a reduction of bacterial genera beneficial for gut homeostasis, which was rescued 30–40 days later in both groups, suggesting a similar impact of the two regimens in challenging bacterial community complexity. Conclusions: Low-dose bismuth quadruple therapy proved to be effective with lower costs and amount of antibiotics and bismuth. Gastrus® might be an option for patients with contraindications to bismuth. L. reuteri was unable to significantly counteract dysbiosis induced by antibiotics. How to administer probiotics to prevent gut microbiota alterations remains an open question.

Increased Risk to Develop Hypertension and Carotid Plaques in Patients with Long-Lasting Helicobacter pylori Gastritis

Helicobacter pylori infection has been reported to be positively associated with hypertension, although with conflicting results. In this study, the relationship between H. pylori infection and hypertension, as well as atherosclerotic carotid lesions, was analyzed. Methods. Clinical records of patients referred to undergo upper endoscopy and gastric biopsy were retrieved. Information regarding the presence of H. pylori infection with atrophy/metaplasia/dysplasia (interpreted as a long-lasting infection), and current or past H. pylori infection was collected, as well as demographic variables, smoking habits, body mass index (BMI), dyslipidemia, diabetes, hypertension, presence of carotid lesions, and current treatment, and analyzed by multivariable regression models. Results. A total of 7152 clinical records from patients older than 30 years (63.4% women) were available for the study. Hypertension was present in 2039 (28.5%) patients and the risk was significantly increased in those with long-lasting H. pylori infection after adjusting for age decades, sex, BMI, cigarette smoking, diabetes, and dyslipidemia (OR 1.17, 95% CI 1.02–1.35). In addition, the long-lasting H. pylori infection was an independent risk for carotid plaques (OR 2.15, 95% CI 1.14–4.09). Conclusions. Our retrospective study demonstrated that long-lasting H. pylori infection is an independent risk factor for hypertension and the presence of carotid lesions after adjusting for potential confounders, although further validation our findings is needed from prospective studies.

Clinical features and natural history of idiopathic peptic ulcers: a retrospective case-control study

Objectives: Peptic ulcer disease (PUD) is still common worldwide and is characterized by high mortality and morbidity. Following the decline of Helicobacter pylori infection, the detection of idiopathic PUD (IPUD) has become more frequent, making diagnosis and treatment more difficult. In this study, the clinical features and natural history of IPUD were analyzed.Methods: This was a retrospective case‒control study conducted in a tertiary care setting (University of Sassari, Italy). Records of 9,212 patients undergoing upper endoscopy from 2002 to 2018 were analyzed. Following the exclusion of H. pylori, NSAIDs, and unusual PUD causes, the remaining were labelled as IPUD. Cases (IPUD) and controls (PUD negative) were compared, adjusting for several covariates through multivariate logistic regression models.Results: Among 380 PUD, 95 were considered IPUD. The proportion rose over the study period in contrast to the decline of H. pylori-PUD. Factors significantly associated with IPUD, after adjusting for all covariates, were age (OR, 3.520; 95% CI, 1.634 - 7.585), male sex (OR, 3.126; 95% CI, 1.888 - 5.176), hospitalization (OR, 2.968; 95% CI, 1.926 - 4.575), and number of medications (OR, 2.808; 95% CI, 1.178 - 6.735). A clinical history positive for PUD was the major risk associated with IPUD (OR, 3.729; 95% CI, 2.050 - 6.785). Patients with IPUD were treated with the highest proton pump inhibitor (PPI) dose for 40-60 days. Follow up endoscopy showed a cure rate of 97.6%.Conclusion: The relative proportion of IPUD is increasing in our population in contrast to the drop of H. pylori-PUD. Treatment with high-dose PPI, and for a long duration, heals IPUD and protects from recurrence.

Role of Helicobacter pylori Infection in Body Height of Adult Dyspeptic Patients

INTRODUCTION

The prevalence of H. pylori infection is high in underdeveloped countries and is associated with growth retardation. In the first half of the 20th century, Sardinia was an underdeveloped region; however, more recent development resulted in a decline in H. pylori infection. Because body height is correlated with health and nutritional status in childhood, the association among H. pylori infection and height was explored.

MATERIALS AND METHODS

A retrospective observational study was conducted involving patients undergoing endoscopy for dyspepsia from 2002 to 2012. H. pylori status was assessed by histology plus the rapid urease test or 13Carbon-urea breath test.

RESULTS

Body height and H. pylori status were assessed in 5045 adult patients: 3257 (64.6%) were women. Patients born after 1950 showed a significant increase in height (average 3.22 cm) compared to patients born before 1950 (163.93 vs 160 cm; 95% confidence interval, CI = 2.74-3.70 cm) (p < .0001). H. pylori-infected patients were nearly 1 cm shorter than uninfected patients (95% CI = -1.35 to·-0.09 cm) (p = .012). The multivariate linear regression analysis showed male gender, birth cohort, and occupational categories to be strongly associated with height, while the weak effect of H. pylori infection disappeared.

CONCLUSIONS

Our results demonstrate a strong secular trend related to body height in Sardinia with a minimal influence of H. pylori infection.

G6PD Deficiency Does Not Enhance Susceptibility for Acquiring Helicobacter pylori Infection in Sardinian Patients

Background

Subjects with glucose-6-phosphate dehydrogenase (G6PD) deficiency may be more susceptible to infections due to impaired leukocyte bactericidal activity. The disorder is common in the Mediterranean area. The aim of this study was to investigate whether G6PD deficiency may be a risk factor for acquiring H. pylori infection.

Methods

We performed a retrospective study. Data from clinical records of 6565 patients (2278 men and 4287 women, median age 51, range 7‒94) who underwent upper endoscopy between 2002 and 2014 were collected. H. pylori status, assessed by histology plus rapid urease test or ¹³C-urea breath test, and G6PD status were also reported. A multiple logistic regression model was used to investigate the association between G6PD deficiency and H. pylori infection.

Results

Enzyme deficiency was detected in 12% (789/6565) of the entire cohort, and more specifically in 8.3% of men and in 14.0% of women. Overall, the proportion of patients positive for H. pylori was 50.6% and 51.5% among G6PD deficient and non-deficient patients (χ² = 0.271; p = 0.315). Moreover, among G6PD-deficient and normal patients the frequency of previous H. pylori infection was similar. After adjustment for age and gender the risk for acquiring H. pylori infection was similar in G6PD-deficient and normal patients. Only age was a strong statistically significant risk predictor.

Conclusions

These results demonstrate for the first time that G6PD deficiency does not enhance patients’ susceptibility to acquire H. pylori infection in Sardinia.

Helicobacter pylori Infection among Patients with Dyspepsia and Intrafamilial Transmission

Introduction

Recurrence is an important problem after Helicobacter pylori infection, and intrafamilial transmission has an important role in recurrence. In this study, we aimed to investigate the significance of intrafamilial transmission for recurrence development after treatment as well as its usefulness in prevention.

Materials and methods

Of the 109 patients who had dyspepsia and underwent endoscopy, 74 patients had H. pylori infection and were enrolled in this study. Infected family members were also detected. Patients were randomly divided into groups I and II, with each group containing 37 individuals. In group I, patients and their infected family members were treated together at the same time. In group II, only the patients were treated. Treatment success was evaluated at the 1st month and evaluation for recurrence was carried out at the 6th month.

Results

Helicobacter pylori infection was detected in 67.8% of the patients with dyspepsia. Two patients in each group did not show up at the 1st month control. Eradication was achieved in 63 of the 70 patients (90.0%) who completed their treatment. After 6 months, patients with successful treatment had no recurrence in any of the 32 patients in group I. There were recurrence in 3 of the 31 patients (9.7%) in group II; however, there was no statistically significant difference between the groups (p = 0.113).

Conclusion

Our study showed that eradication treatment in patients and family members with H. pylori infection resulted in a decrease in the number of recurrences even though it was not statistically significant.

How to cite this article

Yalçin M, Yalçin A, Bengi G, Nak SG. Helicobacter pylori Infection among Patients with Dyspepsia and Intrafamilial Transmission. Euroasian J Hepato-Gastroenterol 2016;6(2):93-96.

Changing prevalence of Helicobacter pylori infection and peptic ulcer among dyspeptic Sardinian patients

Over the past 50 years, the prevalence of Helicobacter pylori infection has fallen as standards of living improved. The changes in the prevalence of infection and its manifestations (peptic ulcer disease and gastric mucosal lesions) were investigated in a large cohort of Sardinians undergoing upper endoscopy for dyspepsia. A retrospective observational study was conducted involving patients undergoing endoscopy for dyspepsia from 1995 to 2013. H. pylori status was assessed by histology plus the rapid urease test or 13C-UBT. Gastric mucosal lesions were evaluated histologically. Data including non-steroidal anti-inflammatory drugs (NSAIDs) use and the presence of peptic ulcers were collected. The prevalence of H. pylori was calculated for each quartile and for each birth cohort from 1910 to 2000. 11,202 records were retrieved for the analysis (62.9% women). The overall prevalence of H. pylori infection was 43.8% (M: 46.6% vs. F: 42.0%; P = 0.0001). A dramatic decrease in the prevalence of infection occurred over the 19-year observation period. The birth cohort effect was evident in each category (quartile) reflecting the continuous decline in H. pylori acquisition. Over time, the prevalence of peptic ulcers also declined, resulting in an increase in the proportion of H. pylori negative/NSAID positive and H. pylori negative/NSAID negative peptic ulcers. The prevalence of gastric mucosal changes also declined despite aging. The decline in H. pylori prevalence over time likely reflects the improvement in socioeconomic conditions in Sardinia such that H. pylori infection and its clinical outcomes including peptic ulcer are becoming less frequent even among dyspeptic patients.

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.

Is There Any Advantage of Treating Partners in Helicobacter pylori Eradication?

Aim. We designed this trial to find answers to the following questions. (1) Does the success rate decrease in a country where HP prevalence is high? (2) Can we provide benefit by simultaneously treating the partners of infected patients? Materials and Methods. The first group consisted of 102 HP-positive patients, and both the patients and their HP-positive partners were treated. The second group consisted of 104 HP-positive patients whose partners were HP-positive but only the patients were treated. The participants in both groups were treated with levofloxacin 500 mg daily, amoxicillin 1 g b.i.d, and lansoprazole 30 mg b.i.d (LAL) for ten days. Results. In the per-protocol analysis, the eradication success rate was found to be 92.2% (94/8) in the first group and 90.4% (94/10) in the second group. No statistically significant difference was found between the two groups (P > 0.05). Conclusions. With regard to the HP eradication rate, no difference was found between treating the HP-positive partners of HP-positive patients simultaneously and not treating them simultaneously. According to these results, we can say that reinfections between partners do not significantly contribute to the failure of eradication.

Evaluation of an Iranian Home-made Helicobacter pylori Stool Antigen ELISA Kit

Background:

Current diagnosis of Helicobacter pylori infection by biopsy-based tests requires invasive sampling. Non-invasive methods such as the H. pylori stool-antigen (HpSA) test may be the best alternative for diagnosis of active infection. However, due to the presence of antigenic-diversity among the strains, various commercial tests have shown some discrepancies in different geographical-areas.

Objectives:

This study evaluates a homemade HpSA kit developed by using the H. pylori antigens from Iranian-isolates for detection of H. pylori in the stool of infected patients.

Patients and Methods:

Based on the endoscopic features and/or a rapid-urease test (RUT), 30 child and 50 adult patients, were recruited. From these candidates, three biopsies for RUT, culture and histology, and a stool-sample, were obtained. Patients were considered as H. pylori-positive if culture alone or RUT plus histology were found to be positive. Presence of H. pylori antigens in their stools was detected by the homemade HpSA test and an imported HpSA kit (Immundiagnostik, Germany).

Results:

Using the biopsy-based tests with RUT, histology and culture, 53% (16/30) of children were diagnosed as H. pylori–positive while using the imported kit 57% and the homemade kit 50% of the candidates showed positive results. Also by the biopsy-based tests, 54% of the adults were diagnosed as H. pylori-positive while by the homemade kit 56% showed positive results. Considering the biopsy-based tests as the gold standard, sensitivity and specificity for the imported kit was 94% and 86%, respectively, while the mean sensitivity and specificity for the homemade kit was 96% and 98%, respectively.

Conclusions:

The homemade kit, compared with the imported kit and biopsy-proven tests may be a valid and reliable method for determining the presence of H. pylori infection in Iran.

Prevalence of Helicobacter pylori infection in bariatric patients: a histologic assessment

BACKGROUND

Studies on rates of Helicobacter pylori (HP) infection in morbidly obese patients awaiting bariatric surgery are conflicting because of small sample size and variability in diagnostic testing. The objective of this study was to determine the rate of biopsy-proven active HP infection in morbidly obese patients undergoing bariatric surgery.

METHODS

Retrospective analysis was done on all morbidly obese patients who underwent bariatric surgery between 2001 and 2009. All patients underwent preoperative upper endoscopy with biopsy to evaluate HP status. All endoscopies and surgeries were performed by a single endoscopist and surgeon, respectively. Data were analyzed with Student t test, Pearson χ(2) test, and logistic regression for multivariate analysis.

RESULTS

The 611 patients included 79 males (12.9%) and 532 females (87.1%). Mean age was 39.9 ± 10.7 years, and mean body mass index (BMI) was 47.8 ± 6.4 kg/m(2). The overall HP infection rate was 23.7%. Rate of infection did not differ between gender (22.8% in males, 23.9% in females; P = .479) or BMI (48.6 ± 6.5 kg/m(2) in HP-positive patients, 47.5 ± 6.4 kg/m(2) in HP-negative patients; P = .087). Patients with HP were older compared with those without infection (41.2 versus 38.7 years; P =.016). Hispanics had a higher prevalence of HP (OR 2.35; P = .023).

CONCLUSION

Increasing BMI is not an independent risk factor for active HP infection within the morbidly obese patient population. Need for invasive testing to detect HP infection in these patients should be re-evaluated. Other methods of detecting active HP infection should be considered as an alternative to invasive or serologic testing.

Selective detection of viable Helicobacter pylori using ethidium monoazide or propidium monoazide in combination with real-time polymerase chain reaction

Because Helicobacter pylori has a role in the pathogenesis of gastric cancer, chronic gastritis and peptic ulcer disease, detection of its viable form is very important. The objective of this study was to optimize a PCR method using ethidium monoazide (EMA) or propidium monoazide (PMA) for selective detection of viable H. pylori cells in mixed samples of viable and dead bacteria. Before conducting the real-time PCR using SodB primers of H. pylori, EMA or PMA was added to suspensions of viable and/or dead H. pylori cells at concentrations between 1 and 100 μM. PMA at a concentration of 50 μM induced the highest DNA loss in dead cells with little loss of genomic DNA in viable cells. In addition, selective detection of viable cells in the mixtures of viable and dead cells at various ratios was possible with the combined use of PMA and real-time PCR. In contrast, EMA penetrated the membranes of both viable and dead cells and induced degradation of their genomic DNA. The findings of this study suggest that PMA, but not EMA, can be used effectively to differentiate viable H. pylori from its dead form.

Non-invasive genotyping of Helicobacter pylori cagA, vacA, and hopQ from asymptomatic children

BACKGROUND

Helicobacter pylori infection is usually acquired in childhood, but little is known about its natural history in asymptomatic children, primarily due to the paucity of non-invasive diagnostic methods. H. pylori strains harboring cagA and specific alleles of hopQ and vacA are associated with increased risk for gastric cancer. Many studies of H. pylori virulence markers in children have the bias that symptomatic subjects are selected for endoscopy, and these children may harbor the most virulent strains. Our aim is to genotype cagA, hopQ, and vacA alleles in stool DNA samples of healthy Colombian children residing in an area with high incidence of gastric cancer, to avoid selection bias resulting from endoscopy.

METHODS

H. pylori status of 86 asymptomatic children was assessed by (13) C-urea breath test (UBT) and PCR. H. pylori 16S rRNA, cagA, hopQ, and vacA genes were amplified from stool DNA samples and sequenced.

RESULTS

UBT was positive in 69 (80.2%) of 86 children; in stool DNA analysis, 78.3% were positive by 16S rRNA PCR. cagA, vacA, and hopQ were detected in 66.1%, 84.6%, and 72.3% of stool DNA samples from 16S rRNA-positive children. Of the children's DNA samples, which revealed vacA and hopQ alleles, 91.7% showed vacA s1 and 73.7% showed type I hopQ. Type I hopQ alleles were associated with cagA positivity and vacA s1 genotypes (p < 0.0001).

CONCLUSIONS

Using stool DNA samples, virulence markers of H. pylori were successfully genotyped in a high percentage of the asymptomatic infected children, revealing a high prevalence of genotypes associated with virulence. Type I hopQ alleles were associated with the presence of cagA and the vacA s1 genotype.

Prevalence of Helicobacter spp in chronic cholecystitis and correlation with changes on the histological pattern of the gallbladder

PURPOSE: Establish the prevalence of Helicobacter spp in chronic cholecystitis and its correlation with the gallbladder's histological findings. METHODS: 100 patients were operated for chronic cholecystitis with cholecystolithiasis. In pathological examination of the gallbladder, were evaluated the presence of metaplasia, dysplasia, lymphoid follicles, anaplasia and tumors that might be related to the presence of Helicobacter plus the presence of the bacilli Giemsa? by optical microscopy. From the DNA extracted from the gallbladder's bile, PCR was performed by using specific primers for the identification of Helicobacter spp with amplification of the 400bp segment of rRNA gene16S, with positive control DNA from Helicobacter pylori. All the cases negative for isolation of genetic material were excluded. The cases of PCRΘ and GiemsaΘ were used as negative control group. The histological findings were compared to the presence of bacilli and PCR data using a chi-square and Fisher's Exact test (CI = 95.0%, p <0.05). RESULTS: Of 68 patients, 42 (61.8%) were PCR? for Helicobacter spp and 19 (27.9%) had Giemsa?. There was no correlation between the two findings. The PCR? for Helicobacter spp was not correlated to the histological findings. The presence of lymphoid follicles and metaplasia was related to the Giemsa? (p = 0.025 and p= 0.039). CONCLUSION: There is high prevalence of Helicobacter spp in patients with chronic cholecystitis and cholecystolithiasis without be correlated with the histological patterns studied.

Effect of FliK mutation on the transcriptional activity of the {sigma}54 sigma factor RpoN in Helicobacter pylori

Helicobacter pylori is a motile Gram-negative bacterium that colonizes and persists in the human gastric mucosa. The flagellum gene regulatory circuitry of H. pylori is unique in many aspects compared with the Salmonella/Escherichia coli paradigms, and some regulatory checkpoints remain unclear. FliK controls the hook length during flagellar assembly. Microarray analysis of a fliK-null mutant revealed increased transcription of genes under the control of the sigma(54) sigma factor RpoN. This sigma factor has been shown to be responsible for transcription of the class II flagellar genes, including flgE and flaB. No genes higher in the flagellar hierarchy had altered expression, suggesting specific and localized FliK-dependent feedback on the RpoN regulon. FliK thus appears to be involved in three processes: hook-length control, export substrate specificity and control of RpoN transcriptional activity.

Application of Stool-PCR test for diagnosis of Helicobacter pylori infection in children

AIM: To evaluate the usefulness of stool-PCR test for diagnosis of Helicobacter pylori (H pylori) infection in pediatric populations.

METHODS: Based on endoscopic features (including nodular gastritis, erosive duodenitis and ulcer) and/or a positive rapid urease test (RUT) obtained during endoscopy, 28 children from a group of children admitted to the Children's Medical Center of Tehran for persistent upper gastrointestinal problems were selected to compare biopsy-based tests with stool-PCR. Their gastric activity and bacterial density were graded by the updated Sydney system, and their first stool after endoscopy was stored at -70°C. Biopsies were cultured on modified campy-blood agar plates and identified by gram-staining, biochemical tests, and PCR. Two methods of phenol-chloroform and boiling were used for DNA extraction from H pylori isolates. Isolation of DNA from stool was performed using a stool DNA extraction kit (Bioneer Inc, Korea). PCR was performed using primers for detection of vacA, cagA, and 16srRNA genes in both isolates and stool.

RESULTS: Sixteen out of 28 child patients (57%) were classified as H pylori positive by biopsy-based tests, of which 11 (39%) were also positive by stool-PCR. Sensitivity and specificity of stool-PCR was 62.5% and 92.3% respectively. H pylori was observed in histological sections for 10 out of 11 stool-positive patients. Association was observed between higher score of H pylori in histology and positivity of stool-PCR. Also association was observed between the more severe form of gastritis and a positive stool-PCR.

CONCLUSION: Association between higher score of H pylori in histology and a positive stool-PCR make it a very useful test for detection of H pylori active infection in children. We also suggest that a simple stool-PCR method can be a useful test for detection of H pylori virulence genes in stool.

Helicobacter pylori: longer survival in deep ground water and sea water than in a nutrient-rich environment

Helicobacter pylori can infect the human stomach through the ingestion of water. Only a few studies on the morphological changes and viability of this bacteria in DGW (deep ground water) have been reported and none in natural seawater (SW). Morphological changes and the culturability of H. pylori after storage in DGW or SW for a week were examined to see if they could be a factor associated with the high infection rate in Japan. An H. pylori strain, ATCC 43504, stored in DGW and in SW at 4 degrees C for 7 days, was examined daily for any ultrastructural changes and culturability. The same H. pylori strain was also cultured in conventional Brucella broth culture liquid medium as control and was similarly observed. Bacteria kept in DGW and SW were found not only to retain their spiral form but also to show better culturability than those kept in the control nutrient-rich medium (p<0.01). Thus, natural waters were found to be more conducive to H. pylori survival than a nutrient-rich medium.

Cost-effectiveness analysis between primary and secondary preventive strategies for gastric cancer

OBJECTIVE

The present study is done to assess the relative cost-effectiveness, optimal initial age, and interscreening interval between primary and secondary prevention strategies for gastric cancer.

METHODS

Base-case estimates, including variables of natural history, efficacy of intervention, and relevant cost, were derived from two preventive programs targeting a high-risk population. Cost-effectiveness was compared between chemoprevention with (13)C urea breath testing followed by Helicobacter pylori (H. pylori) eradication and high-risk surveillance based on serum pepsinogen measurement and confirmed by endoscopy. The main outcome measure was cost per life-year gained with a 3% annual discount rate.

RESULTS

The incremental cost-effectiveness ratio (ICER) for once-only chemoprevention at age 30 years versus no screening was U.S. $17,044 per life-year gained. Eradication of H. pylori at later age or with a periodic scheme yielded a less favorable result. Annual high-risk screening at age of 50 years versus no screening resulted in an ICER of U.S. $29,741 per life-year gained. The ICERs of surveillance did not substantially vary with different initial ages or interscreening intervals. Chemoprevention could be dominated by high-risk surveillance when the initial age was older than 44 years. Otherwise, chemoprevention was more cost-effective than high-risk surveillance, either at ceiling ratios of U.S. $15,762 or up to U.S. $50,000. The relative cost-effectiveness was most sensitive to the infection rate of H. pylori and proportion of early gastric cancer in all detectable cases.

CONCLUSIONS

Early H. pylori eradication once in lifetime seems more cost-effective than surveillance strategy. However, the choice is still subject to the risk of infection, detectability of early gastric cancer, and timing of intervention.

Non-pylori Helicobacteraceae in the upper digestive tract of asymptomatic Venezuelan subjects: detection of Helicobacter cetorum-like and Candidatus Wolinella africanus-like DNA

BACKGROUND

The spectrum of human non-pylori Helicobacter infections is expanding, with species such as H. heilmannii and H. felis occasionally being associated with gastritis. However, the existence of non-pylori Helicobacter colonization in asymptomatic subjects has not been evaluated. The aim of this study was to investigate whether Helicobacter species other than pylori are present in the upper digestive tract of asymptomatic human subjects.

MATERIALS AND METHODS

A Helicobacteraceae-specific semi-nested polymerase chain reaction (PCR) assay was used to detect Helicobacter-like organisms in the upper digestive tract of 91 Venezuelan volunteers (aged 18-68 years, 41 females, 50 males). Species were identified by denaturing gradient gel electrophoresis analysis and sequencing of the PCR products.

RESULTS

We detected DNA sharing 99-100% sequence identity in over 300-400 bp with the 16S rRNA genes of H. pylori, H. cetorum, and Candidatus Wolinella africanus in 76%, 16%, and 15% of the subjects, respectively. Multiple colonization was documented in 10% of the subjects: H. cetorum and Candidatus W. africanus (4%), H. pylori and Candidatus W. africanus (4%), and H. pylori and H. cetorum (2%).

CONCLUSIONS

Our results suggest that non-pylori Helicobacteraceae colonization is relatively common in the Venezuelan asymptomatic population. This is the first report documenting the presence of H. cetorum DNA in the human upper digestive tract, and the second report of the recently discovered Candidatus W. africanus.

A new model for the transmission of Helicobacter pylori: role of environmental reservoirs as gene pools to increase strain diversity

Twenty-five years after the first successful cultivation and isolation of Helicobacter pylori, the scientific community is still struggling to understand the way(s) this bacterium is transmitted among the human population. Here, both epidemiologic and microbiologic evidence addressing this matter is reviewed and explored to conclude that most H. pylori successful colonizations are derived from direct person-to-person contact and that even though exposure of humans to H. pylori from environmental sources is a very common event, in most occasions the host is able to fight off infection. In addition, under a new model developed here, we propose that the near elimination of environmental reservoirs is the main responsible for the lower prevalence observed in the more industrialized countries by acting on two levels: by decreasing the number of direct infections and by diminishing the number of intraspecies recombination events for producing strain variation within H. pylori.

Immunochromatographic monoclonal test for detection of Helicobacter pylori antigen in stool is useful in children from high-prevalence developing country

BACKGROUND

Tests to detect Helicobacter pylori antigens in feces for diagnosis of infection in children demonstrate controversial results. One novel and fast monoclonal test improves diagnostic accuracy in adults, but clinical evidence of its usefulness at pediatric age is insufficient to date. The objective of this work was to evaluate the diagnostic accuracy of this test in a sample of Mexican children.

METHODS

We conducted a transversal study in 150 selected children with digestive symptoms suggestive of organic disease in whom a clinical history was conducted in addition to a fast monoclonal test (ImmunoCardSTAT HpSA, Meridian Diagnostics) performed by immunochromatography. Patients were submitted to endoscopy and histopathologic study.

RESULTS

Of the 150 children (mean age 7.8 +/- 4.7 years), 107 (71.3%) were positive for the test, and presence of H. pylori was confirmed histologically in 109 (72.7%) children, with sensitivity of 96.3% (95% CI = 95.8-96.8), specificity of 95.1% (95% CI = 93.9-96.4), and accuracy of 96.0% (95% CI, -95.6 to -96.3); pretest probability was 0.73, while post-test probability was 0.98. Infection rate and test accuracy increased with age.

CONCLUSIONS

This test is useful for detecting H. pylori infection in children of all ages, and is a good alternative for screening studies in developing countries with elevated prevalence, due to its being fast, noninvasive, inexpensive, and easy to carry out.

Body indices and basic vital signs in Helicobacter pylori positive and negative persons

It has been hypothesized that Helicobacter pylori (Hp) infection may contribute to reduced stature, risk of hypertension or obesity. The aim was to evaluate body indices in Hp positive and negative persons. A total of 2436 subjects (4–100 years old) were tested for Hp status by ¹³Curea breath test. Data on height and weight were collected for 84%, and blood pressure for 80% of the study subjects. The prevalence of Hp infection was 41.6%. The odds ratio for a 10-year increase in age was 1.21 (95% CI 1.17–1.25, p-value <0.001). Statistically significant negative association of Hp positivity with body height was most pronounced in the younger age groups, while a positive association of Hp positivity with body mass index was only seen in those aged 15+ years. There was a negative effect of Hp positivity on systolic and diastolic blood pressure in subjects below 25 and a relatively strong positive effect on blood pressure in subjects over 65 years. Residual confounding by social characteristics as a possible explanation for the associations of Hp positivity with height and blood pressure cannot be excluded. Unmeasured factors related to social and family environment may cause the apparent association between Hp positivity and children’s growth and blood pressure.

Natural maternal transmission of H. pylori in Mongolian gerbils

AIM

To investigate maternal H. pylori infection status to determine the potential of maternal transmission.

METHODS

In the present study, we examined these issues in an experimental murine model, which is a Mongolian gerbil model that has been reported as an optimal laboratory animal model to study H. pylori. Pregnant Mongolian gerbils, infected experimentally with H. pylori, were divided into as four groups. Following the experimental design, the stomachs of the mother and litters were isolated and assessed for transmission of H. pylori at the prenatal period, parturition day, 1-wk old and 3-wk old respectively. Bacterial culture and polymerase chain reaction (PCR) were used to examine the presence of transmitted H. pylori.

RESULTS

All litters showed no transmission of H. pylori during pregnancy and at parturition day. However, they revealed 33.3% and 69.6% at 1-wk and 3-wk of age respectively by PCR.

CONCLUSION

These results suggested that vertical infection during the prenatal period or delivery procedure is unlikely as a route of mother-to-child H pylori infection. It may be that H. pylori is acquired through breast-feeding, contaminated saliva and fecal-oral transmission during co-habitation.

Is Helicobacter pylori a cause of atrial fibrillation?

Inflammation has been implicated in the pathogenesis of cardiovascular diseases. C-reactive protein, a sensitive marker of systemic inflammation, has recently been reported to be significantly higher in patients with atrial fibrillation (AF) compared with a control group with no history of atrial arrhythmia. Elevated C-reactive protein levels in patients with AF reflects an underlying inflammatory process. Histological anomalies in the atria of patients with AF have also been observed. These anomalies may have an inflammatory basis, although it is not known if any structural changes within the atria are a cause or a consequence of the arrhythmia. Ongoing chronic infection(s) has been suggested as a possible cause of the inflammatory process demonstrated in patients with AF. Helicobacter pylori, a Gram-negative bacterium more commonly known for infecting the gastric mucosa and causing peptic ulcers, is a noncardiac factor that has been controversially reported to be associated with cardiovascular diseases. This article gives a brief overview of AF and specifically explores the recent evidence that suggests that Helicobacter pylori infection causes AF.

Respiratory diseases and Helicobacter pylori infection: is there a link?

Recent studies suggest an epidemiological association between Helicobacter pylori infection and several extra-gastroduodenal pathologies, including cardiovascular, rheumatic, skin and liver diseases. The observed associations might be explained by a role of H. pylori infection in the pathogenesis of certain extra-digestive disorders, as a variety of inflammatory mediators are activated by H. pylori infection. The present review summarizes the current literature, including our own studies, concerning the association between respiratory diseases and H. pylori infection. A small number of epidemiological and serologic case-control studies suggest that patients with chronic obstructive pulmonary disease have an increased seroprevalence of H. pylori. A frequent coexistence of bronchiectasis and H. pylori infection has also been found. Moreover, recent studies have shown an increased prevalence of H. pylori infection in patients with pulmonary tuberculosis and in those with lung cancer. On the other hand, bronchial asthma does not seem to be related to H. pylori infection. At present, there is no definite proof of a causal relationship between H. pylori and respiratory diseases. The primary evidence rests on case-control studies, concerning relatively small numbers of patients. Future studies should be large enough for moderate-sized effects to be assessed or registered reliably. The activation of inflammatory mediators by H. pylori infection might be the pathogenetic mechanism underlying the observed associations. Therefore, the role of genetic predisposition of the infected host, the presence of strain-specific virulence factors and the serum concentration of proinflammatory markers in H. pylori-infected patients with respiratory diseases need further evaluation.

Third-line rescue therapy for Helicobacter pylori infection

H pylori gastric infection is one of the most prevalent infectious diseases worldwide. The discovery that most upper gastrointestinal diseases are related to H pylori infection and therefore can be treated with antibiotics is an important medical advance. Currently, a first-line triple therapy based on proton pump inhibitor (PPI) or ranitidine bismuth citrate (RBC) plus two antibiotics (clarithromycin and amo-xicillin or nitroimidazole) is recommended by all consensus conferences and guidelines. Even with the correct use of this drug combination, infection can not be eradicated in up to 23% of patients. Therefore, several second line therapies have been recommended. A 7 d quadruple therapy based on PPI, bismuth, tetracycline and metronidazole is the more frequently accepted. However, with second-line therapy, bacterial eradication may fail in up to 40% of cases. When H pylori eradication is strictly indicated the choice of further treatment is controversial. Currently, a standard third-line therapy is lacking and various protocols have been proposed. Even after two consecutive failures, the most recent literature data have demonstrated that H pylori eradication can be achieved in almost all patients, even when antibiotic susceptibility is not tested. Different possibilities of empirical treatment exist and the available third-line strategies are herein reviewed.