A comparison of Helicobacter pylori and H. heilmannii gastritis. A matched control study involving 404 patients

Triple-drug combination therapy versus six-month proton pump inhibitor monotherapy in non-Helicobacter pylori Helicobacter eradication, and hyperacid environment preference of Helicobacter suis: a clinical study

BACKGROUND

At present, eradication regimens for non-Helicobacter pylori Helicobacter (NHPH) have not been established yet. We investigated effectiveness of the standard triple-drug combination therapy for Helicobacter pylori eradication and of a proton pump inhibitor (PPI) monotherapy in eradication of NHPH.

METHODS

Subjects were the patients who were diagnosed with NHPH-infected gastritis based on microscopic findings, helical-shaped organisms obviously larger than Helicobacter pylori, in the gastric mucosal specimens using Giemsa staining at Kenwakai Hospital between November 2010 and September 2021, whose NHPH species were identified by polymerase chain reaction (PCR) analysis of urease genes in endoscopically-biopsied samples, and who consented to NHPH eradication with either the triple-drug combination therapy for one week or a PPI monotherapy for six months. Six months after the completion of eradication, its result was determined with esophagogastroduodenoscopy, microscopic examination, and PCR analysis. In cases of unsuccessful eradication, a second eradication with the other therapy was suggested to the patient.

RESULTS

PCR analysis detected NHPH in 38 patients: 36 as Helicobacter suis and two as Helicobacter heilmannii/Helicobacter ailurogastricus. Fourteen Helicobacter suis-infected and one Helicobacter heilmannii/Helicobacter ailurogastricus-infected patients requested eradication therapy. The triple-drug combination therapy succeeded in four of five patients, while the PPI monotherapy succeeded in five of 10 patients. Three of five patients who had been unsuccessful with the latter therapy requested the triple-drug combination therapy as the second eradication and all three were successful. In total, the triple-drug combination therapy succeeded in seven out of eight (87.5%) attempted cases, while the PPI monotherapy in five out of 10 (50%) attempted cases.

CONCLUSIONS

In NHPH eradication, the triple-drug combination therapy was considered to be effective to some extent and to become the first-line therapy. While, although less successful, PPI monotherapy appeared to be a potentially promising option particularly for patients with allergy or resistance to antibiotics. Effectiveness of PPI monotherapy may be attributed to hyperacid environment preference of Helicobacter suis and PPI's acid-suppressive effect. Additionally, male predominance in NHPH-infected gastritis patients may be explained by gender difference in gastric acid secretory capacity. However, further evidence needs to be accumulated.

STUDY REGISTRATION

This study was approved by the Research Ethics Committee of Kenwakai Hospital (No. 2,017,024).

Clinical presentation and outcomes of Helicobacter heilmannii gastritis in children in the New England region of the United States

OBJECTIVE

To describe the clinical, endoscopic, histologic, and treatment outcomes of Helicobacter heilmannii (H. heilmannii) associated gastritis in children in the New England region of the United States.

METHODS

Retrospective study of children (1-18 years) with H. heilmannii identified on gastric mucosal biopsies from two pediatric centers over a 21-year period, January 2000-December 2021. Cases were identified by querying pathology databases at each institution. Demographic and clinical data were obtained from the medical record. Endoscopic and histologic findings were extracted from endoscopy and pathology reports, respectively.

RESULTS

Thirty-eight children were diagnosed with H. heilmannii-associated gastritis during the study period. The mean age at diagnosis was 10.1 ± 5.3 years, and 25/38 (66%) cases were male. Abdominal pain (32%) and nausea with or without vomiting (26%) were the most common symptoms. Thirty-two children (84%) had endoscopic findings including gastric nodularity (55%) and erythema (26%). All children had histologic signs of chronic gastritis, including those with normal endoscopic exams. Antibiotic regimens used for treating Helicobacter pylori were frequently prescribed. Of the 17 children who underwent a follow-up endoscopy (range 2-68 months), 15 (88%) did not have H. heilmannii identified on gastric biopsies.

CONCLUSION

H. heilmannii was an infrequent but potential cause of epigastric abdominal pain and nausea in our cohort of New England children. While morphologically distinct from H. pylori, the bacteria can result in similar endoscopic and histologic findings of nodularity and chronic gastritis, respectively. The rate of eradication, as assessed by histology following treatment with H. pylori therapies, was below the 90% recommended goal for antimicrobial therapies.

H pylori-Negative MALT-Associated Extranodal Marginal Zone Lymphoma: A Comprehensive Case Report and Literature Review

Extranodal marginal zone B-cell lymphoma (ENMZL) of mucosa-associated lymphoid tissue (MALT), a rare subtype of B-cell lymphoma, is typically associated with Helicobacter pylori (H pylori) infection, especially in gastric cases. However, this article presents 2 unique cases of H pylori-negative colonic ENMZL, challenging the conventional understanding of the disease. The first case involves an 80-year-old male diagnosed with Stage 1E ENMZL in the descending colon, and the second describes a 74-year-old male with sigmoid colon ENMZL. Both cases lacked H pylori infection, adding complexity to their management. Accompanying these case studies is a comprehensive literature review, delving into the epidemiology, pathology, clinical features, diagnosis, and treatment of H pylori-negative ENMZL, with a focus on gastrointestinal involvement. This review highlights the importance of considering H pylori-negative cases in ENMZL diagnosis and management, illustrating the need for further research and individualized treatment approaches in this uncommon lymphoma subtype.

Role of non-Helicobacter pylori gastric Helicobacters in helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma

Marginal zone lymphomas rank as the third most prevalent form of non-Hodgkin B-cell lymphoma, trailing behind diffuse large B-cell lymphoma and follicular lymphoma. Gastric mucosa-associated lymphoid tissue lymphoma (GML) is a low-grade B-cell neoplasia frequently correlated with Helicobacter pylori (H. pylori)-induced chronic gastritis. On the other hand, a specific subset of individuals diagnosed with GML does not exhibit H. pylori infection. In contrast to its H. pylori-positive counterpart, it was previously believed that H. pylori-negative GML was less likely to respond to antimicrobial therapy. Despite this, surprisingly, in-creasing evidence supports that a considerable proportion of patients with H. pylori-negative GML show complete histopathological remission after bacterial eradication therapy. Nonetheless, the precise mechanisms underlying this treatment responsiveness are not yet fully comprehended. In recent years, there has been growing interest in investigating the role of non-H. pylori gastric helicobacters (NHPHs) in the pathogenesis of H. pylori-negative GML. However, additional research is required to establish the causal relationship between NHPHs and GML. In this minireview, we examined the current understanding and proposed prospects on the involvement of NHPHs in H. pylori-negative GML, as well as their potential response to bacterial eradication therapy.

Management of Helicobacter pylori infection: the Maastricht VI/Florence consensus report

Helicobacter pyloriInfection is formally recognised as an infectious disease, an entity that is now included in the International Classification of Diseases 11th Revision. This in principle leads to the recommendation that all infected patients should receive treatment. In the context of the wide clinical spectrum associated with Helicobacter pylori gastritis, specific issues persist and require regular updates for optimised management.The identification of distinct clinical scenarios, proper testing and adoption of effective strategies for prevention of gastric cancer and other complications are addressed. H. pylori treatment is challenged by the continuously rising antibiotic resistance and demands for susceptibility testing with consideration of novel molecular technologies and careful selection of first line and rescue therapies. The role of H. pylori and antibiotic therapies and their impact on the gut microbiota are also considered.Progress made in the management of H. pylori infection is covered in the present sixth edition of the Maastricht/Florence 2021 Consensus Report, key aspects related to the clinical role of H. pylori infection were re-evaluated and updated. Forty-one experts from 29 countries representing a global community, examined the new data related to H. pylori infection in five working groups: (1) indications/associations, (2) diagnosis, (3) treatment, (4) prevention/gastric cancer and (5) H. pylori and the gut microbiota. The results of the individual working groups were presented for a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in various clinical fields.

Effect of Acid Suppressants on Non–Helicobacter pylori Helicobacters Within Parietal Cells

We investigated the effect of increased pH induced by acid suppressants on the viability of non–Helicobacter pylori helicobacters (NHPHs) within parietal cell intracellular canaliculi and fundic glandular lumina by immunohistochemistry, electron microscopy, quantitative PCR, urea breath tests, and using a bilayer culture system. Three months before the experiment, mice were infected with the NHPH H. suis and then treated with famotidine (2 mg/kg body weight [BW], once daily), lansoprazole (30 mg/kg BW, once daily), or vonoprazan (20 mg/kg BW, once daily) for 3 days. Immunohistochemical studies using the TUNEL method, quantitative PCR analysis, and urea breath tests were performed. PCR analysis showed a decrease in the NHPH quantity after vonoprazan treatment. Urea breath tests revealed a significant decrease in the NHPH urease activity after vonoprazan, lansoprazole, and famotidine treatments for 3 days; however, 4 days after the treatment, urease activity reversed to the pretreatment level for each treatment group. Electron microscopy revealed an increase in the damaged NHPH after vonoprazan treatment. The TUNEL method revealed apoptotic NHPH within parietal cells after vonoprazan treatment. The bilayer culture results demonstrated that NHPH moved more quickly at a pH of 4.0 than at a pH of 3.0, 5.0, and 6.5, and electron microscopy revealed a change from the spiral form to the coccoid form under near-neutral pH conditions. We thus proposed that acid suppressants, especially vonoprazan, induce NHPH damage by altering pH.

Gastric Helicobacter species associated with dogs, cats and pigs: significance for public and animal health

This article focuses on the pathogenic significance of Helicobacter species naturally colonizing the stomach of dogs, cats and pigs. These gastric "non-Helicobacter (H.) pylori Helicobacter species" (NHPH) are less well-known than the human adapted H. pylori. Helicobacter suis has been associated with gastritis and decreased daily weight gain in pigs. Several studies also attribute a role to this pathogen in the development of hyperkeratosis and ulceration of the non-glandular stratified squamous epithelium of the pars oesophagea of the porcine stomach. The stomach of dogs and cats can be colonized by several Helicobacter species but their pathogenic significance for these animals is probably low. Helicobacter suis as well as several canine and feline gastric Helicobacter species may also infect humans, resulting in gastritis, peptic and duodenal ulcers, and low-grade mucosa-associated lymphoid tissue lymphoma. These agents may be transmitted to humans most likely through direct or indirect contact with dogs, cats and pigs. Additional possible transmission routes include consumption of water and, for H. suis, also consumption of contaminated pork. It has been described that standard H. pylori eradication therapy is usually also effective to eradicate the NHPH in human patients, although acquired antimicrobial resistance may occasionally occur and porcine H. suis strains are intrinsically less susceptible to aminopenicillins than non-human primate H. suis strains and other gastric Helicobacter species. Virulence factors of H. suis and the canine and feline gastric Helicobacter species include urease activity, motility, chemotaxis, adhesins and gamma-glutamyl transpeptidase. These NHPH, however, lack orthologs of cytotoxin-associated gene pathogenicity island and vacuolating cytotoxin A, which are major virulence factors in H. pylori. It can be concluded that besides H. pylori, gastric Helicobacter species associated with dogs, cats and pigs are also clinically relevant in humans. Although recent research has provided better insights regarding pathogenic mechanisms and treatment strategies, a lot remains to be investigated, including true prevalence rates, exact modes of transmission and molecular pathways underlying disease development and progression.

Investigation of endoscopic findings in nine cases of Helicobacter suis-infected gastritis complicated by gastric mucosa-associated lymphoid tissue lymphoma

BACKGROUND

We have previously reported that eradication therapy was more effective against Helicobacter pylori (Hp)-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma in non-Helicobacter pylori Helicobacter (NHPH)-positive cases than in NHPH-negative cases and that the infection status of NHPH could be a predictive marker for the efficacy of eradication therapy for H. pylori negative gastric MALT lymphoma. However, a diagnostic test for NHPH infection has not yet been clinically established. In this study, we investigated the endoscopic findings in cases of H. suis-infected gastritis associated with gastric MALT lymphoma reported at our institution.

MATERIALS AND METHODS

Participants were selected from cases of gastric MALT lymphoma who underwent esophagogastroduodenoscopy at Hiroshima University Hospital, who were negative for the API2-MALT1 gene, and who received eradication therapy as a first-line treatment. We examined the endoscopic findings in nine cases from this group in which H. suis infection was confirmed by polymerase chain reaction.

RESULTS

Endoscopic findings, such as cracked mucosa, spotty redness, nodular gastritis-like appearance, and white marbled appearance, which have been reported as characteristics of NHPH gastritis, were observed in multiple cases. The most common endoscopic findings in this study were cracked mucosa (7/9 cases), followed by spotty redness (6/9 cases), nodular gastritis-like appearance (5/9 cases), and white marbled appearance (2/9 cases).

CONCLUSIONS

Our study may serve as a reference for re-evaluation of the diagnostic criteria for H. suis infection and indications for eradication therapy, particularly for cases of H. pylori negative gastric MALT lymphoma, where endoscopic findings such as those seen in this study were observed in the background mucosa.

Helicobacter Species and Their Association with Gastric Pathology in a Cohort of Dogs with Chronic Gastrointestinal Signs

Prevalence of individual Helicobacter species, data evaluating their association with gastric pathology and comparison of accuracy of diagnostic techniques are limited. The aims of this study were to determine the prevalence of gastric Helicobacter species, their association with gastric pathology, and to compare diagnostic techniques. Gastric biopsies from 84 privately-owned dogs with chronic gastrointestinal signs were obtained endoscopically. Helicobacters were detected using PCR, cytology, urease test, and histopathology. PCR detected helicobacters in 71.4% of dogs. Helicobacter heilmannii sensu stricto (s.s.) was the predominant species. Mixed infection was detected in 40% of PCR positive dogs. Gastritis was diagnosed in 38.5% of Helicobacter positive and 47.4% of Helicobacter negative dogs. Mono-infection was associated with 2.4 times increased odds of having more severe inflammation compared to mixed infection. Erosions and ulcers were common endoscopic lesions. Cytology had sensitivity/specificity of 88.3/91.7%. Association between infection and lymphoid follicular hyperplasia was demonstrated.

Non-Helicobacter pylori Helicobacter (NHPH) positive gastric cancer

Genetic analysis and culturing techniques for gastric non-Helicobacter pylori Helicobacter (NHPH) are progressing. NHPH is reported to accompany nodular gastritis, gastric MALT lymphoma, and mild gastritis. However, only a few gastric cancer cases infected by NHPH have been reported. PCR analysis specific for NHPH and H. pylori was performed for DNA from gastric mucosa of 282 Korean gastric cancer patients, who were treated with endoscopic submucosal dissection. For more precise strain detection of NHPH, NHPH-positive mucosa was stained by immunohistochemistry specific for Helicobacter suis. The Cancer Genome Atlas (TCGA) classification was analyzed for these 3 gastric cancer sub-groups by in situ hybridization and immunohistochemistry. Among 281 patients, 3 patients (1.1%) were positive for NHPH. One patient (Patient 1) was also positive for H. pylori by PCR, another patient (Patient 3) was positive for serum IgG for H. pylori, and the other patient (Patient 2) had no evidence for H. pylori infection. Gastric mucosa of Patients 2 and 3 were positive for H. suis staining. All three NHPH-positive gastric cancers were located in the antrum, and belonged to the Chromosomal Instability Type of TCGA classification. Gastric NHPH can be a cause of gastric cancer, although likely with lower pathogenesis than H. pylori.

Current Status of the Spectrum and Therapeutics of Helicobacter pylori-Negative Mucosa-Associated Lymphoid Tissue Lymphoma

Simple Summary

The prevalence of Helicobacter pylori (HP)-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma has increased over the last two decades, whereas that of HP-positive gastric MALT lymphoma has decreased. Although the role of first-line antibiotics in the treatment of HP-negative gastric MALT lymphomas remains ambiguous, several case series have reported that a first-line HP eradication therapy (HPE)-like regimen could result in complete remission in a proportion of patients with localized HP-negative gastric MALT lymphoma. Previous sporadic reports have indicated that certain patients with extragastric MALT lymphoma can respond to first-line antibiotic treatment as well. These findings suggest that, in contrast to antibiotic-unresponsive tumors, antibiotic-responsive tumors may be recognized within the spectrum of HP-negative MALT lymphoma. In addition to conventional chemotherapy and immunochemotherapy, macrolide antibiotics and immunomodulatory drugs have been previously used and demonstrated to be efficacious. This article provides the spectrum and therapeutics for HP-negative MALT lymphoma.

Abstract

Helicobacter pylori (HP)-unrelated mucosa-associated lymphoid tissue (MALT) lymphoma includes the majority of extragastric MALT lymphomas and a small proportion of gastric MALT lymphomas. Although the role of first-line antibiotics in treating HP-negative gastric MALT lymphomas remains controversial, HP eradication therapy (HPE)-like regimens may result in approximately 20–30% complete remission (CR) for patients with localized HP-negative gastric MALT lymphoma. In these patients, H. heilmannii, H. bizzozeronii, and H. suis were detected in sporadic gastric biopsy specimens. Extragastric MALT lymphoma is conventionally treated with radiotherapy for localized disease and systemic chemotherapy for advanced and metastatic diseases. However, a proportion of extragastric MALT lymphomas, such as ocular adnexal lesions and small intestinal lesions, were reported to be controlled by antibiotics for Chlamydophila psittaci and Campylobacter jejuni, respectively. Some extragastric MALT lymphomas may even respond to first-line HPE. These findings suggest that some antibiotic-responsive tumors may exist in the family of HP-negative MALT lymphomas. Two mechanisms underlying the antibiotic responsiveness of HP-negative MALT lymphoma have been proposed. First, an HPE-like regimen may eradicate the antigens of unknown bacteria. Second, clarithromycin (the main component of HPE) may have direct or indirect antineoplastic effects, thus contributing to the CR of these tumors. For antibiotic-unresponsive HP-negative MALT lymphoma, high-dose macrolides and immunomodulatory drugs, such as thalidomide and lenalidomide, have reported sporadic success. Further investigation of new treatment regimens is warranted.

Prevalence, clinical features, and esophagogastroduodenoscopy (EGD) findings of non-Helicobacter pylori Helicobacter infection: A study of 50 cases at a single facility in Japan

BACKGROUND AND AIM

There are only a few reports of non-Helicobacter pylori Helicobacter (NHPH) gastritis in Japanese patients. We aimed to examine its prevalence, clinical features, and esophagogastroduodenoscopy (EGD) findings based on 50 patients encountered in one facility.

MATERIALS AND METHODS

Subjects were all patients who had undergone gastric mucosal biopsy endoscopically at Kenwakai Hospital for approximately 10 years. NHPH infection was diagnosed by microscopic findings of Giemsa staining performed on all specimens. PCR analysis of urease genes was performed to detect and identify NHPH, when informed consent was obtained. Helicobacter pylori-diagnostic tests were also performed. NHPH-infected patients were questioned about symptoms and animal contact.

RESULTS

NHPH gastritis was found in 50 of 3847 patients (1.30%). The percentage increased to 3.35% (30 of 896 patients) in the latter 2 years and 4 months with increasing recognition of its characteristic endoscopic findings by endoscopists. PCR analysis, performed in 30 patients, detected NHPH in 28 patients: 26 as Helicobacter suis and 2 as Helicobacter heilmanii/Helicobacter ailurogastricus. Helicobacter pylori-diagnostic tests were almost negative. However, anti-H. pylori antibody showed high-negative titer (3.0-9.9 U/ml) in 12. Of 50 patients (consisting of 49 men and 1 woman), almost all were asymptomatic, and 25 were keeping pets. Regarding EGD findings, in all 50 patients, "crack-like mucosa" and/or nodular gastritis was noted in gastric antrum, and regular arrangement of collecting venules (RAC) was noted in gastric corpus. None of the patients infected with NHPH were co-infected with H. pylori.

CONCLUSIONS

The prevalence was finally estimated to be approximately 3.35%. Helicobacter suis was the most common NHPH species. "Crack-like mucosa" and/or nodular gastritis in gastric antrum, RAC in gastric corpus, and H. pylori-negativity by H. pylori-diagnostic tests especially containing a high-negative titer of anti-H. pylori antibody may indicate NHPH infection.

Transmission of Helicobacter pylori between a human and two dogs: A case report

BACKGROUND

Whereas non-Helicobacter pylori helicobacters, which are frequently detected in the stomachs of dogs and cats as a source of zoonoses, have attracted considerable attention, the role of pets in H. pylori epidemiology is unclear. In our previous study, an H. pylori infection was detected in the stomach of a dog (Dog 1). Here, we investigated the H. pylori infection status in the female offspring of Dog 1 (Dog 2) and its owner within the same household.

MATERIALS AND METHODS

Biopsy specimens were obtained from the dog's owner and tested for H. pylori. DNA from gastric biopsy samples of Dog 1, gastric fluid sediment of Dog 2, and bacteria from the stomach of the owner was obtained, and Helicobacter genus- and species-specific PCRs were performed. Then, sequence analyses of the partial region of the ureAB gene were conducted.

RESULTS

Samples from both dogs and the owner reacted positively in the genus-specific PCR and negative in the Helicobacter felis-, Helicobacter bizzozeronii-, and Helicobacter heilmannii sensu stricto-specific PCRs. All three samples also reacted positively in the H. pylori-specific PCR. Sequences of the partial ureAB gene from all subjects were identical.

CONCLUSIONS

The results suggested that the two dogs and their owner were infected with an identical H. pylori strain. This report is the first to demonstrate that H. pylori can be transmitted between humans and dogs. Further studies are required to investigate the risk factors for the transmission of H. pylori between humans and dogs from the perspective of preventive epidemiology.

Acute Peptic Ulcer Disease Caused by Non-Helicobacter pylori-Helicobacter

Human infection by Non-Helicobacter pylori-Helicobacter is rare and most commonly transmitted through direct contact with animals. The clinical presentation in most cases is chronic epigastric abdominal pain and it usually leads to chronic gastritis. We present an uncommon case of a patient with acute onset abdominal pain secondary to acute peptic ulcer disease caused by Helicobacter heilmannii who underwent successful treatment. We also conducted a review of the literature to understand the epidemiology, etiology, clinical presentation, and the best diagnostic and treatment modalities for Non-H. pylori-Helicobacter infections.

Evidence of Helicobacter spp. in Saliva and Gastric Mucosa of Domestic Dogs in the Central Region of Rio Grande do Sul, Brazil

Helicobacter pylori is a spiral-shaped bacterium, which plays a role in the aetiology of gastric diseases in humans. Non-H. pylori Helicobacter (NHPH) species naturally colonise the stomach of animals and also induce gastric lesions in humans, highlighting their zoonotic importance. We evaluated the gastric bacterial colonisation density and gastric lesions and sought to identify the main phylogenetic groups of the Helicobacter spp. obtained from dogs in the central region of Rio Grande do Sul, Brazil, with this study aiming to investigate the occurrence of Helicobacter spp. in saliva and gastric samples from these dogs. This study included 35 dogs and used analysis such as cytology, histopathology, PCR, rapid urease testing, and phylogenetic analysis. Of the dogs, 94.3% were positive for Helicobacter spp., and these bacteria were present in the stomach of 32 dogs and saliva of eight. Respectively, eight, 15, and nine dogs had mild, moderate, and severe colonisation. Lymphocytic-plasmacytic infiltrate was the main gastric lesion. However, the presence of Helicobacter and the density appeared to be unrelated to the gastric lesions. The samples possessed a high nucleotide identity with remarkably similar sequences among some of the species of NHPH such as H. heilmannii s.s., H. salomonis, H. felis, and H. bizzozeronii. The saliva of domestic dogs, even of those who appear clinically healthy, can cause Helicobacter infection in humans and other animals, with, in these dogs, increased density, occurrence rate, and predominance of NHPH of zoonotic importance being found in the stomach with a lower occurrence of Helicobacter spp. in the saliva.

Gastric mucosa-associated lymphoid tissue lymphoma in conjunction with multiple lymphomatous polyposis in the context of Helicobacter pylori and Helicobacter suis superinfection

A 53-year-old woman visited a doctor and complained of chest discomfort after meals. Esophagogastroduodenoscopy showed multiple granular elevations in the gastric body. After biopsies from the elevations, she was diagnosed with mucosa-associated lymphoid tissue (MALT) lymphoma. Polymerase chain reaction also detected Helicobacter pylori and H. suis. Treatment to eradicate H. pylori and H. suis was successful. Endoscopic examination after the bacterial eradication treatment showed that multiple granular elevations remained in the gastric body; however, no lymphoma cells were found during histopathological examination. Thus, we reported a case of H. pylori-positive gastric MALT lymphoma with a unique morphology associated with H. suis superinfection.

Hellenic consensus on Helicobacter pylori infection

The Hellenic Society of Gastroenterology recently organized the “Hellenic consensus on Helicobacter pylori (H. pylori) infection”. The aim of this publication is to report the guidelines in order to aid the national gastroenterology community in the management of H. pylori infection. Forty-one delegates from all Greek regions, including gastroenterologists, pathologists, clinical microbiologists, epidemiologists and basic scientists, were invited to this meeting. The participants were allocated to 1 of the 4 main topics of the meeting: i.e., H. pylori diagnosis and association with diseases; H. pylori and gastric cancer; H. pylori and extragastric associated disorders; and H. pylori treatment. The results of each subgroup were submitted to a final consensus vote that included all participants. Relevant data based on international and Greek publications were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded. The cutoff level of 70% was considered as acceptance for the final statement. It is hoped that the recommendations and conclusions of this report will guide Greek doctors in their daily practice concerning the management of H. pylori infection.

Helicobacter suis Is Associated With Mortality in Parkinson's Disease

Helicobacter pylori has been implicated in the pathogenesis of Parkinson's disease (PD). Its eradication, in a randomized placebo-controlled trial, improved PD hypokinesia. Helicobacter species zoonosis might explain excess mortality from PD and non-Hodgkin lymphoma in livestock, but not arable, farmers. Indeed, Helicobacter is causally-associated with gastric lymphoma. We have previously shown that the relative-frequency, H. suis to H. pylori, was 10-times greater in 60 PD-patients than in 256 controls. We now go on to evaluate the pathological significance of H. suis, detected in gastric-biopsy DNA-extracts by ureA-based species-specific qPCR, validated by amplicon sequencing. The methodology had been cross-validated by a carR-based PCR. The pathological significance is put in context of H. pylori detection [urea-breath-test (UBT) with biopsy-culture, and, if negative, PCR], and the potential reservoir in pigs. Here, we explore, in these 60 PD-patients, associations of H. suis status with all-cause-mortality, and with orthostatic cardiovascular and blood profiling. H. suis had been detected in 19 of the 60 PD-patients on one or more occasion, only two (with co-existent H. pylori) being UBT positive. We found that the hazard-of-death (age-at-diagnosis- and gender-adjusted) was 12 (95% CI 1,103) times greater (likelihood-ratio test, P = 0.005) with H. suis-positivity (6/19) than with negativity (2/40: one lost to follow-up). UBT-values did not influence the hazard. H. suis-positivity was associated with lower standing mean-arterial-pressure [6 (1, 11) mmHg], H. pylori-positivity having no effect. The lower total lymphocyte count with H. pylori-positivity [-8 (-1, -14) %] was not seen with H. suis, where T-cell counts were higher [24 (2, 52) %]. Regarding the potential zoonotic reservoir in the UK, Helicobacter-like-organism frequency was determined in freshly-slaughtered pigs, nature ascertained by sequencing. Organisms immunostaining for Helicobacter, with corkscrew morphology typical of non-H. pylori Helicobacter, were seen in 47% of 111 pig-antra. We conclude that H. suis is associated with all-cause-mortality in PD and has a potential zoonotic reservoir.

Helicobacter suis infection alters glycosylation and decreases the pathogen growth inhibiting effect and binding avidity of gastric mucins

Helicobacter suis is the most prevalent non-Helicobacter pylori Helicobacter species in the human stomach and is associated with chronic gastritis, peptic ulcer disease, and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. H. suis colonizes the gastric mucosa of 60-95% of pigs at slaughter age, and is associated with chronic gastritis, decreased weight gain, and ulcers. Here, we show that experimental H. suis infection changes the mucin composition and glycosylation, decreasing the amount of H. suis-binding glycan structures in the pig gastric mucus niche. Similarly, the H. suis-binding ability of mucins from H. pylori-infected humans is lower than that of noninfected individuals. Furthermore, the H. suis growth-inhibiting effect of mucins from both noninfected humans and pigs is replaced by a growth-enhancing effect by mucins from infected individuals/pigs. Thus, Helicobacter spp. infections impair the mucus barrier by decreasing the H. suis-binding ability of the mucins and by decreasing the antiprolific activity that mucins can have on H. suis. Inhibition of these mucus-based defenses creates a more stable and inhabitable niche for H. suis. This is likely of importance for long-term colonization and outcome of infection, and reversing these impairments may have therapeutic benefits.

Presence of gastric Helicobacter species in children suffering from gastric disorders in Southern Turkey

BACKGROUND

Infections with gastric Helicobacter spp. are associated with gastritis, peptic ulceration, and malignancies. Helicobacter pylori is the most prevalent Helicobacter species colonizing the human stomach. Other gastric non-H. pylori helicobacters (NHPHs) have been described in 0.2%-6% of human patients with gastric disorders. Nevertheless, due to difficulties in the diagnosis of NHPH infections and lack of routine screening, this is most likely an underestimation of their true prevalence. To the best of our knowledge, no studies have been performed in the presence of Helicobacter spp. in children suffering from gastric disorders in Southern Turkey.

MATERIALS AND METHODS

In total, 110 children with gastric complaints were examined at the Cukurova University Balcali hospital, Turkey. Gastroscopy was performed to evaluate the presence of gastric mucosal lesions. Biopsies of the pyloric gland zone were taken for histopathological analysis, rapid urease testing, and presence of Helicobacter spp. DNA by PCR.

RESULTS

Based on the PCR results, the prevalence of Helicobacter spp. was 32.7% (36/110). H. pylori was found in 30.9% (34/110), H. suis in 1.8% (2/110), and H. heilmannii/H. ailurogastricus in 0.9% (1/110) of the human patients. A mixed infection with H. pylori and H. suis was present in one patient. The presence of mucosal abnormalities, such as nodular inflammation, ulceration, and hyperemia, as well as gastritis, was significantly higher in Helicobacter spp. positive patients.

CONCLUSION

Helicobacter pylori, H. suis, and H. heilmannii/H. ailurogastricus were present in children with gastric complaints. Infection with these pathogens may be involved in the development of gastritis and ulceration.

Pathologic Features of Infectious Gastritis

This manuscript presents a review of infectious causes of gastritis aimed at the practicing anatomic pathologist. We shall highlight unique histologic findings and clinical attributes that will assist those analyzing endoscopically obtained mucosal biopsies of the stomach or resection specimens.

The Resolution of Helicobacter suis-associated Gastric Lesions after Eradication Therapy

A reddish depressed lesion was found in the corpus of the stomach of a 56-year-old man. Gastric biopsy showed no findings of mucosa-associated lymphoid tissue lymphoma, including lympho-epithelial lesions. A urea breath test, stool antigen test and serum IgG antibody to Helicobacter pylori test were negative. Magnifying endoscopy using narrow-band-imaging showed no malignant structures. Gastric biopsy specimens were subjected to immunohistochemistry and a polymerase chain reaction, which identified Helicobacter suis infection. Triple therapy with esomeprazole, metronidazole, and amoxicillin was administered for 10 days. Three months later, endoscopy showed the significant improvement of the lesion. H. suis infection should be considered in chronic gastritis patients without H. pylori infection.

Evidence for a primate origin of zoonotic Helicobacter suis colonizing domesticated pigs

Helicobacter suis is the second most prevalent Helicobacter species in the stomach of humans suffering from gastric disease. This bacterium mainly inhabits the stomach of domesticated pigs, in which it causes gastric disease, but it appears to be absent in wild boars. Interestingly, it also colonizes the stomach of asymptomatic rhesus and cynomolgus monkeys. The origin of modern human-, pig- or non-human primate-associated H. suis strains in these respective host populations was hitherto unknown. Here we show that H. suis in pigs possibly originates from non-human primates. Our data suggest that a host jump from macaques to pigs happened between 100 000 and 15 000 years ago and that pig domestication has had a significant impact on the spread of H. suis in the pig population, from where this pathogen occasionally infects humans. Thus, in contrast to our expectations, H. suis appears to have evolved in its main host in a completely different way than its close relative Helicobacter pylori in humans.

Zoonotic potential of Helicobacter spp

The genus Helicobacter contains more than 35 species. Helicobacter pylori is the most important in terms of human health. Discovery of these helicobacters gives opportunity to understand the relationship between these bacteria which colonise the animal and human gut and their effect on the host. Infection with Helicobacter spp. and the associated diseases in their hosts allow us to study the pathogenic mechanisms. The potential zoonotic pathway for the transmission of Helicobacter spp. and epidemiology of this genus, deserve more attention to these emerging pathogens.

Species-specific immunity to Helicobacter suis

BACKGROUND

Helicobacter (H.) suis is mainly associated with pigs, but is also the most prevalent gastric non-H. pylori Helicobacter species found in humans. Both H. pylori and H. suis may cause persistent infection of the stomach. Several immune evasion mechanisms have been proposed for H. pylori, which focus to a great extent on its major virulence factors, which are absent in H. suis. The aim of this study was to gain more knowledge on immune evasion by H. suis.

MATERIALS AND METHODS

Cytokine expression kinetics were monitored in the stomach of BALB/c mice experimentally infected with H. suis. The cytokine expression profile in the stomach of naturally H. suis-infected pigs was also determined. Subsequently, the effect of H. suis on murine and porcine dendritic cell (DC) maturation and their ability to elicit T-cell effector responses was analyzed.

RESULTS

Despite a Th17/Th2 response in the murine stomach, the inflammatory cell influx was unable to clear H. suis infection. H. suis-stimulated murine bone marrow-derived dendritic cells induced IL-17 secretion by CD4⁺ cells in vitro. Natural H. suis infection in pigs evoked increased expression levels of IL-17 mRNA in the antrum and IL-10 mRNA in the fundus. In contrast to mice, H. suis-stimulated porcine monocyte-derived dendritic cells were unable to express MHCII molecules on their cell surface. These semimature DCs induced proliferation of T-cells, which showed an increased expression of TGF-β and FoxP3 mRNA levels.

CONCLUSIONS

Helicobacter suis might evade host immune responses by skewing toward a Treg-biased response.

Epidemiological study of gastric Helicobacter spp. in dogs with gastrointestinal disease in Japan and diversity of Helicobacter heilmannii sensu stricto

Epidemiological and pathological studies of Helicobacter spp. in canine stomachs in Japan were performed to investigate strain specific pathogenicity. Gastric biopsies from 144 dogs with gastrointestinal diseases were evaluated for the presence of Helicobacter spp. using genus and species specific PCRs for Helicobacter felis, Helicobacter bizzozeronii, Helicobacter heilmannii sensu stricto (s.s.) and Helicobacter pylori. PCR indicated that 50/144 (34.7%) dogs were infected with Helicobacter spp. Of the genus positive samples, 21/50 could not be amplified by any of the species specific PCRs. To investigate Helicobacter at the species level, partial ureAB gene sequences from 48/50 genus positive samples were determined; 47 strains were identified. Thirty-five strains from 45 cases were closely related to H. heilmannii s.s. (89-99% sequence similarity), seven strains from seven cases were closely related to H. bizzozeronii (95-99% sequence similarity), three strains from three cases were closely related to Helicobacter felis (86%, 98% and 99% sequence similarity), one strain from one case was closely related to Helicobacter salomonis (99% sequence similarity) and one strain from one case was closely related to H. pylori (99% sequence similarity). Dogs infected with Helicobacter spp. most similar to H. heilmannii s.s. had a higher frequency of moderate to severe gastritis than dogs negative for Helicobacter spp. (P=0.044). In conclusion, the predominant Helicobacter spp. detected in canine stomachs in our study were most closely related to H. heilmannii s.s. and displayed substantial genetic diversity. Infection with Helicobacter spp. may be associated with more severe gastritis in dogs.

Prevalence of Gastric Non-Helicobacter pylori-Helicobacters in Japanese Patients with Gastric Disease

BACKGROUND

Non-Helicobacter pylori-helicobacters (NHPH) compose a group of gram negative zoonotic bacteria that may induce in humans gastric diseases including gastritis, gastroduodenal ulcer and MALT lymphoma. Their prevalence in the general population has previously been reported to 0.1-6.2%, although such reports still remain less in number.

AIMS

This study aimed at estimating the prevalence of gastric NHPH in Japanese people, and further aimed at linking this to different gastric diseases and co-infection with H. pylori.

METHODS

Endoscopically obtained biopsy samples from 280 Japanese patients with various gastric diseases were collected. Samples were analyzed by immunohistochemistry and by species-specific PCR for detection of gastric helicobacters.

RESULTS

The total prevalence of gastric NHPH among 280 Japanese patients was 6.1%, and the prevalence of H. pylori was 65.7%. There was no significant difference in prevalence of either NHPH or H. pylori when infected with H. pylori or NHPH, respectively. NHPH infection was found to be the highest in patients with gastric MALT lymphoma and duodenal ulcer, the former being independent of co-infection with H. pylori and the latter being dependent.

CONCLUSIONS

This study reports a total prevalence of 6.1% of gastric NHPH in Japanese patients, and further highlights gastric MALT lymphoma and duodenal ulcer (when co-infected with H. pylori) as important related diseases.

Management of Helicobacter pylori infection-the Maastricht V/Florence Consensus Report

Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.

Helicobacter-negative gastritis: polymerase chain reaction for Helicobacter DNA is a valuable tool to elucidate the diagnosis

BACKGROUND

Helicobacter-negative gastritis has been increasingly reported. Molecular techniques as the polymerase chain reaction (PCR) may detect bacterial DNA in histologically negative gastritis.

AIM

To evaluate of Helicobacter PCR in gastric biopsies for the daily diagnostics of Helicobacter-negative gastritis.

METHODS

Over a 5-year period, routine biopsies with chronic gastritis reminiscent of Helicobacter infection, but negative by histology, were tested by using a H. pylori specific PCR. Subsequently, PCR-negative samples were re-evaluated using PCR for other Helicobacter species.

RESULTS

Of the 9184 gastric biopsies, 339 (3.7%) with histological-negative gastritis and adequate material were forwarded to PCR analysis for H. pylori and 146 (43.1%) revealed a positive result. In 193 H. pylori DNA-negative biopsies, re-analysis using PCR primers for other Helicobacter species, revealed further 23 (11.9%) positive biopsies, including 4 (2.1%) biopsies with H. heilmannii sensu lato. PCR-positive biopsies showed a higher overall inflammatory score, more lymphoid follicles/aggregates and neutrophils (P < 0.05). No Helicobacter DNA was found in control biopsies of 48 patients with neither primer set (P < 0.0001). In 274 patients with an endoscopic description, detection of H. pylori DNA was associated with ulcers and erosions (P < 0.01). Over all, in 339 histologically-negative gastric biopsies, Helicobacter DNA was detected in 169 (49.9%) samples with at least one primer set.

CONCLUSION

Molecular testing offers a sensitive and specific diagnosis to a selected group of patients, in whom adequate searches for bacteria by conventional histology have resulted in the unsatisfactory diagnosis of H. pylori-negative gastritis.

Prevalence of Coinfection with Gastric Non-Helicobacter pylori Helicobacter (NHPH) Species in Helicobacter pylori-infected Patients Suffering from Gastric Disease in Beijing, China

BACKGROUND

The Helicobacter heilmannii sensu lato (H. heilmannii s.l.) group consists of long, spiral-shaped bacteria naturally colonizing the stomach of animals. Moreover, bacteria belonging to this group have been observed in 0.2-6% of human gastric biopsy specimens, and associations have been made with the development of chronic gastritis, peptic ulceration, and gastric MALT lymphoma in humans.

MATERIALS AND METHODS

To gain insight into the prevalence of H. heilmannii s.l. infections in patients suffering from gastric disease in China, H. heilmannii s.l. species-specific PCRs were performed on DNA extracts from rapid urease test (RUT)-positive gastric biopsies from 1517 patients followed by nucleotide sequencing. At the same time, Helicobacter pylori cultivation and specific PCR was performed to assess H. pylori infection in these patients.

RESULTS

In total, H. heilmannii s.l. infection was detected in 11.87% (178/1499) of H. pylori-positive patients. The prevalence of H. suis, H. felis, H. bizzozeronii, H. heilmannii sensu stricto (s.s.), and H. salomonis in the patients was 6.94%, 2.20%, 0.13%, 0.07%, and 2.54%, respectively. Results revealed that all patients with H. heilmannii s.l. infection were co-infected with H. pylori, and some patients were co-infected with more than two different Helicobacter species.

CONCLUSIONS

Helicobacter heilmannii s.l. infections are fairly common in Chinese patients. This should be kept in mind when diagnosing the cause of gastric pathologies in patients. Helicobacter suis was shown to be by far the most prevalent H. heilmannii s.l.species.

[Role of animal gastric Helicobacter species in human gastric pathology]

Animal Helicobacter species other than Helicobacter pylori are also able to cause human gastritis, gastric ulcers, and MALT lymphomas. Animal Helicobacter species are presented with typical spiral fastidious microorganisms colonizing the gastric mucosa of different animals. Bacteria initially received their provisional name Helicobacter heilmannii, and out of them at least five species colonizing the gastric mucosa of pigs, cats, and dogs were isolated later on. A high proportion of these diseases are shown to be zoonotic. Transmission of pathogens occurs by contact. The factors of bacterial pathogenicity remain little studied.

Helicobacter suis-Infected Nodular Gastritis and a Review of Diagnostic Sensitivity for Helicobacter heilmannii-Like Organisms

Helicobacter heilmannii-like organisms (HHLOs) are associated with mucosa-associated lymphoid tissue lymphoma and peptic ulcer. However, the sensitivity of diagnostic tests for HHLOs, such as rapid urease test (RUT), urea breath test (UBT) and blood antibody, is not high. Tightly coiled spiral microorganisms were found in the gastric mucosal biopsy specimen of a 48-year-old asymptomatic woman. Her findings were positive for RUT and UBT, but negative for blood antibody and stool antigen against H. pylori. A 7-day course of esomeprazole, amoxicillin and clarithromycin was administered, resulting in the successful eradication of the HHLOs. Analysis of the 16S rRNA and urease genes suggested a diagnosis of the HHLO H. suis. The sensitivity results of RUT, UBT, culture, blood antibody, immunohistochemistry and stool antigen were 40.0, 14.8, 0, 23.1, 40.0 and 0%, respectively. We report asymptomatic nodular gastritis due to an HHLO. Histological techniques, most likely with smears, are expected to be the most effective method for diagnosing infections by HHLOs, and genetic diagnosis by polymerase chain reaction can be very useful to identify the species of HHLOs.

Role of γ-glutamyltranspeptidase in the pathogenesis of Helicobacter suis and Helicobacter pylori infections

Helicobacter (H.) suis can colonize the stomach of pigs as well as humans, causing chronic gastritis and other gastric pathological changes including gastric ulceration and mucosa-associated lymphoid tissue (MALT) lymphoma. Recently, a virulence factor of H. suis, γ-glutamyl transpeptidase (GGT), has been demonstrated to play an important role in the induction of human gastric epithelial cell death and modulation of lymphocyte proliferation depending on glutamine and glutathione catabolism. In the present study, the relevance of GGT in the pathogenesis of H. suis infection was studied in mouse and Mongolian gerbil models. In addition, the relative importance of H. suis GGT was compared with that of the H. pylori GGT. A significant and different contribution of the GGT of H. suis and H. pylori was seen in terms of bacterial colonization, inflammation and the evoked immune response. In contrast to H. pyloriΔggt strains, H. suisΔggt strains were capable of colonizing the stomach at levels comparable to WT strains, although they induced significantly less overall gastric inflammation in mice. This was characterized by lower numbers of T and B cells, and a lower level of epithelial cell proliferation. In general, compared to WT strain infection, ggt mutant strains of H. suis triggered lower levels of Th1 and Th17 signature cytokine expression. A pronounced upregulation of B-lymphocyte chemoattractant CXCL13 was observed, both in animals infected with WT and ggt mutant strains of H. suis. Interestingly, H. suis GGT was shown to affect the glutamine metabolism of gastric epithelium through downregulation of the glutamine transporter ASCT2.

Helicobacter heilmannii sensu stricto-related gastric ulcers: A case report

A spiral bacterium (SH9), morphologically different from Helicobacter pylori (H. pylori), was found in a 62-year-old woman’s gastric mucosa. Gastroscopic examination revealed multiple gastric ulcers near the pyloric ring; mapping gastric biopsy showed mild mononuclear infiltration with large lymphoid follicles in the antrum, without corpus atrophy. Urea breath test and H. pylori culture were negative, but Giemsa staining of biopsies revealed tightly coiled bacteria that immunostained with anti-H. pylori antibody. Sequencing of SH9 16S rRNA and the partial urease A and B subunit genes showed that the former sequence had highest similarity (99%; 1302/1315 bp) to Helicobacter heilmannii (H. heilmannii) sensu stricto (H. heilmannii s.s.) BC1 obtained from a bobcat, while the latter sequence confirmed highest similarity (98.3%; 1467/1493 bp) to H. heilmannii s.s. HU2 obtained from a human. The patient was diagnosed with multiple gastric ulcers associated with H. heilmannii s.s. infection. After triple therapy (amoxicillin, clarithromycin, and lansoprazole) with regimen for eradicating H. pylori, gastroscopy showed ulcer improvement and no H. heilmannii s.s. upon biopsy.

Significantly higher frequency of Helicobacter suis in patients with idiopathic parkinsonism than in control patients

BACKGROUND

There is increased proportional mortality from Parkinson's disease amongst livestock farmers. The hypokinesia of Parkinson's disease has been linked to Helicobacter pylori. H. suis is the most common zoonotic helicobacter in man.

AIM

To compare the frequency of H. suis, relative to H. pylori, in gastric biopsies of patients with idiopathic parkinsonism (IP) and controls from gastroenterology services.

METHODS

DNA extracts, archived at a Helicobacter Reference Laboratory, from IP patient and gastroenterology service biopsies were examined anonymously for H. suis, using species-specific RT-PCR.

RESULTS

Relative risk of having H. suis in 60 IP patients compared with 256 controls was 10 times greater than that of having H. pylori. In patients with IP and controls, respectively, frequencies of H. suis were 27 (exact binomial 95% C.I. 15, 38) and 2 (0, 3)%, and of H. pylori, 28 (17, 40) and 16 (12, 21)%. Excess of H. suis in IP held when only the antral or corporal biopsy was considered. Of 16 IP patients with H. suis, 11 were from 19 with proven H. pylori eradication, 3 from 17 pre-H. pylori eradication, 2 from 24 H. pylori culture/PCR-negative. Frequency was different between groups (P = 0.001), greatest where H. pylori had been eradicated. Even without known exposure to anti-H. pylori therapy, H. suis was more frequent in IP patients (5/41) than in controls (1/155) (P = 0.002). Partial multilocus sequence typing confirmed that strains from IP patients (6) and control (1) differed from RT-PCR standard strain.

CONCLUSIONS

Greater frequency of H. suis in idiopathic parkinsonism appears exaggerated following H. pylori eradication. Multilocus sequence testing comparison with porcine strains may clarify whether transmission is from pigs/porcine products or of human-adapted, H. suis-like, bacteria.

Diversity in bacterium-host interactions within the species Helicobacter heilmannii sensu stricto

Helicobacter (H.) heilmannii sensu stricto (s.s.) is a zoonotic bacterium that naturally colonizes the stomach of dogs and cats. In humans, this microorganism has been associated with gastritis, peptic ulcer disease and mucosa associated lymphoid tissue (MALT) lymphoma. Little information is available about the pathogenesis of H. heilmannii s.s. infections in humans and it is unknown whether differences in virulence exist within this species. Therefore, a Mongolian gerbil model was used to study bacterium-host interactions of 9 H. heilmannii s.s. strains. The colonization ability of the strains, the intensity of gastritis and gene expression of various inflammatory cytokines in the stomach were determined at 9 weeks after experimental infection. The induction of an antrum-dominant chronic active gastritis with formation of lymphocytic aggregates was shown for 7 strains. High-level antral colonization was seen for 4 strains, while colonization of 4 other strains was more restricted and one strain was not detected in the stomach at 9 weeks post infection. All strains inducing a chronic active gastritis caused an up-regulation of the pro-inflammatory cytokine IL-1β in the antrum. A reduced antral expression of H⁺/K⁺ ATPase was seen in the stomach after infection with 3 highly colonizing strains and 2 highly colonizing strains caused an increased gastrin expression in the fundus. In none of the H. heilmannii s.s.-infected groups, IFN-γ expression was up-regulated. This study demonstrates diversity in bacterium-host interactions within the species H. heilmannii s.s. and that the pathogenesis of gastric infections with this microorganism is not identical to that of an H. pylori infection.

Survival of Helicobacter suis bacteria in retail pig meat

Helicobacter (H.) suis colonizes the gastric mucosa of pigs world-wide and is the most prevalent non-Helicobacter pylori Helicobacter species in humans. This agent might be transmitted to humans by manipulation or consumption of contaminated pork. H. suis is a very fastidious micro-organism and is extremely difficult to isolate. Therefore, we developed a non-culture dependent, quantitative detection method allowing differentiation of viable from dead H. suis bacteria in pork. This was established by a combination of ethidium bromide monoazide (EMA) treatment and real-time (RT)-PCR. This EMA RT-PCR was applied to 50 retail pork samples. In two samples, viable H. suis bacteria were detected. Sequence analysis of the obtained PCR products confirmed the presence of H. suis DNA. Viable H. suis bacteria persisted for at least 48h in experimentally contaminated pork. In conclusion, consumption of contaminated pork may constitute a new route of transmission for H. suis infections in humans.

Clinical characteristics of Helicobacter heilmannii- versus Helicobacter pylori-associated gastritis in Chinese patients

AIM: To compare the endoscopic and histopathological characteristics of Helicobacter heilmannii (H. heilmannii)- versusHelicobacter pylori (H. pylori)-associated gastritis in Chinese patients.

METHODS: Gastric biopsy specimens from 53559 consecutive patients treated at Peking University Third Hospital from January 2003 to January 2010 were reviewed retrospectively. All cases of chronic gastritis were evaluated based on the Updated Sydney System. Endoscopic and histopathological characteristics of cases with H. heilmannii infection were compared with those with H. pylori infection.

RESULTS: There were 46 cases with H. heilmannii infection (0.1%) and 18326 cases with H. pylori infection (34.2%). Compared to H. pylori-associated gastritis, H. heilmannii-associated gastritis showed a lower bacterial density (P < 0.001), less severe mononuclear cell infiltration (P < 0.001) and neutrophil activity (P < 0.001), and endoscopic findings of H. heilmannii-associated gastritis were devoid of ulcer (P = 0.021). H. heilmannii density showed a significant correlation with neutrophil activity (P = 0.02), but not with chronic inflammation (P = 0.159). The percentages of patients with mucosal atrophy, intestinal metaplasia and intraepthelial neoplasia in the H. heilmannii-associated gastritis group were 23.9%, 21.7% and 4.3%, respectively, and there was no significant difference in the prevalence and degree of these precancerous lesions between the two groups. A case of signet-ring cell carcinoma concomitant with H. heilmannii infection was detected.

CONCLUSION: H. heilmannii-associated gastritis is uncommon and milder than H. pylori-associated gastritis. The observation that there were no significant differences between two groups in the prevalence and degree of mucosal atrophy, intestinal metaplasia and intraepthelial neoplasia suggests that H. heilmannii may be partly responsible for malignant-associated lesions just as H. pylori does. In addition, one case of signet-ring cell carcinoma concomitant with H. heilmannii infection was noted.

The local immune response of mice after Helicobacter suis infection: strain differences and distinction with Helicobacter pylori

Helicobacter (H.) suis colonizes the stomach of pigs and is the most prevalent gastric non-H. pylori Helicobacter species in humans. Limited information is available on host immune responses after infection with this agent and it is unknown if variation in virulence exists between different H. suis strains. Therefore, BALB/c and C57BL/6 mice were used to compare colonization ability and gene expression of various inflammatory cytokines, as determined by real-time PCR, after experimental infection with 9 different H. suis strains. All strains were able to persist in the stomach of mice, but the number of colonizing bacteria at 59 days post inoculation was higher in stomachs of C57BL/6 mice compared to BALB/c mice. All H. suis strains caused an upregulation of interleukin (IL)-17, which was more pronounced in BALB/c mice. This upregulation was inversely correlated with the number of colonizing bacteria. Most strains also caused an upregulation of regulatory IL-10, positively correlating with colonization in BALB/c mice. Only in C57BL/6 mice, upregulation of IL-1β was observed. Increased levels of IFN-γ mRNA were never detected, whereas most H. suis strains caused an upregulation of the Th2 signature cytokine IL-4, mainly in BALB/c mice. In conclusion, the genetic background of the murine strain has a clear impact on the colonization ability of different H. suis strains and the immune response they evoke. A predominant Th17 response was observed, accompanied by a mild Th2 response, which is different from the Th17/Th1 response evoked by H. pylori infection.

Complete remission of gastric plasmacytoma following eradication of "Candidatus Helicobacter heilmannii"

This is the first case report of gastric plasmacytoma associated with "Candidatus Helicobacter heilmannii" ('H. heilmannii') infection. The patient was a 40-year-old woman with epigastric discomfort. Upper gastrointestinal endoscopy demonstrated a white granular lesion on the wall of the gastric body. Histological studies showed numerous eosinophilic globules expanding the lamina propria mucosae. Immunohistochemically, the cells with these globules stained positive for CD138, CD79a, immunoglobulin (Ig) M, and kappa light chain, but negative for CD20, IgG, IgA, and lambda light chain. A diagnosis of plasmacytoma was made. Although a Helicobacter pylori infection was not detected, the patient received H. pylori eradication treatment. Two months after H. pylori eradication treatment, an upper gastrointestinal endoscopy showed a reduction of the white granular lesion. Eighteen months after eradication treatment, endoscopy, endoscopic ultrasonography and histological studies revealed complete remission of the lesion. No relapse has been documented 30 months after the initial diagnosis of plasmacytoma. Retrospectively, analysis of biopsy specimens removed before eradication treatment demonstrated that this patient had 'H. heilmannii' infection. Therefore, H. pylori eradication therapy should be considered as a potential first-line therapy for early-stage gastric plasmacytoma with or without H. pylori infection.

Neonatal Fc receptor for IgG (FcRn) expressed in the gastric epithelium regulates bacterial infection in mice

Neonatal Fc receptors for immunoglobulin (Ig)G (FcRn) assume a central role in regulating host IgG levels and IgG transport across polarized epithelial barriers. We have attempted to elucidate the contribution of FcRn in controlling Helicobacter infection in the stomach. C57BL/6J wild-type or FcRn(-/-) mice were infected with Helicobacter heilmannii, and gastric lesions, bacterial load and the levels of antigen-specific IgG in serum and gastric juice were analyzed. The elevated levels of anti-H. heimannii IgG in gastric juice were observed exclusively in wild-type mice but not in FcRn(-/-) mice. In contrast, an increase in lymphoid follicles and bacterial loads along with deeper gastric epithelium invasion were noted in FcRn(-/-) mice. C57BL/6J wild-type or FcRn(-/-) mice were also infected with Helicobacter pylori SS1, and the results of the bacterial load in stomachs of these mice and the anti-H. pylori IgG levels in serum and gastric juice were similar to those from H. heilmannii infection. Our data suggest that FcRn can be functionally expressed in the stomach, which is involved in transcytosis of IgG, and prevent colonization by H. heilmannii and the associated pathological consequences of infection.

Characterization of the Gastric Immune Response in Cheetahs (Acinonyx jubatus) With Helicobacter-Associated Gastritis

Captive cheetahs have an unusually severe progressive gastritis that is not present in wild cheetahs infected with the same strains of Helicobacter. This gastritis, when severe, has florid lymphocyte and plasma cell infiltrates in the epithelium and lamina propria with gland destruction, parietal cell loss, and, in some cases, lymphoid follicles. The local gastric immune response was characterized by immunohistochemistry in 21 cheetahs with varying degrees of gastritis. The character of the response was similar among types of gastritis except that cheetahs with severe gastritis had increased numbers (up to 70%) of lamina proprial CD79a+CD21– B cells. CD3+CD4+ T cells were present in the lamina propria, and CD3+CD8α+ T cells were within the glandular epithelium. Lymphoid aggregates had follicular differentiation with a central core of CD79a+/CD45R+ B cells and with an outer zone of CD3+ T cells that expressed both CD4 and CD8 antigens. MHC II antigens were diffusely expressed throughout the glandular and superficial epithelium. No cheetah had evidence of autoantibodies against the gastric mucosa when gastric samples from 30 cheetahs with different degrees of gastritis were incubated with autologous and heterologous serum. These findings indicate that T-cell distribution in cheetahs is qualitatively similar to that in other species infected with Helicobacter but that large numbers of lamina propria activated B cells and plasma cells did distinguish cheetahs with severe gastritis. Further research is needed to determine whether alterations in the Th1:Th2 balance are the cause of this more plasmacytic response in some cheetahs.

Endocrine impact of Helicobacter pylori: Focus on ghrelin and ghrelin o-acyltransferase

Ghrelin is predominantly produced by the gastric enteroendocrine cell compartment and is octanoylated by the recently discovered ghrelin o-acyltransferase (GOAT) before secretion into the bloodstream. This octanoylation is essential for many of the biological properties of ghrelin including appetite stimulation and anti-inflammatory properties as only the acylated form of ghrelin binds to the ghrelin receptor, the growth hormone secretagogue receptor (GHS-R). Given the gastric location of ghrelin production, it is perhaps not surprising that insult to the gastric mucosa affects circulating ghrelin levels in humans. Helicobacter pylori (H. pylori) infects more than fifty percent of the world’s population and once established within the gastric mucosa, can persist for life. Infection is associated with chronic gastritis, gastric atrophy and ulceration, reduced appetite and a lower body mass index (BMI). The large majority of studies investigating levels of circulating ghrelin and ghrelin expression in the stomach in patients with H. pylori infection indicate that the bacterium has a negative impact on ghrelin production and/or secretion. Eradication of infection restores ghrelin, improves appetite and increases BMI in some studies, however, a causative relationship between H. pylori-associated serum ghrelin decline and food intake and obesity has not been established. Most studies measure total ghrelin in the circulation although the measurement of the ratio of acyl/total ghrelin gives a clearer indication that the ghrelin acylation process is altered during infection and atrophy. GOAT is essential for the production of biologically-active, acyl ghrelin and the impact of H. pylori on GOAT expression and activity will be highly informative in the future.

Role of bacteria in oncogenesis

Although scientific knowledge in viral oncology has exploded in the 20th century, the role of bacteria as mediators of oncogenesis has been less well elucidated. Understanding bacterial carcinogenesis has become increasingly important as a possible means of cancer prevention. This review summarizes clinical, epidemiological, and experimental evidence as well as possible mechanisms of bacterial induction of or protection from malignancy.