Helicobacter pylori in health and disease

Nonhelical Helicobacter pylori Mutants Show Altered Gland Colonization and Elicit Less Gastric Pathology than Helical Bacteria during Chronic Infection

Half of all humans harbor Helicobacter pylori in their stomachs. Helical cell shape is thought to facilitate H. pylori's ability to bore into the protective mucus layer in a corkscrew-like motion, thereby enhancing colonization of the stomach. H. pylori cell shape mutants show impaired colonization of the mouse stomach, highlighting the importance of cell shape in infection. To gain a deeper understanding of how helical cell morphology promotes host colonization by H. pylori, we used three-dimensional confocal microscopy to visualize the clinical isolate PMSS1 and an isogenic straight-rod mutant (Δcsd6) within thick longitudinal mouse stomach sections. We also performed volumetric image analysis to quantify the number of bacteria residing within corpus and antral glands in addition to measuring total CFU. We found that straight rods show attenuation during acute colonization of the stomach (1 day or 1 week postinfection) as measured by total CFU. Our quantitative imaging revealed that wild-type bacteria extensively colonized antral glands at 1 week postinfection, while csd6 mutants showed variable colonization of the antrum at this time point. During chronic infection (1 or 3 months postinfection), total CFU were highly variable but similar for wild-type and straight rods. Both wild-type and straight rods persisted and expanded in corpus glands during chronic infection. However, the straight rods showed reduced inflammation and disease progression. Thus, helical cell shape contributes to tissue interactions that promote inflammation during chronic infection, in addition to facilitating niche acquisition during acute infection.

Exploring the impact of Helicobacter pylori on gut microbiome composition

Helicobacter pylori (H. pylori) is known to colonize gastric mucosa, induce inflammation, and alter gastric microbiota resulting in a spectrum of gastric diseases. Likewise, changes in gut microbiota have recently been linked with various metabolic and inflammatory diseases. While extensive number of studies were published examining the relationship between H. pylori and gastric microbiota, little is known about the impact of H. pylori on downstream gut microbiota. In this study, we performed 16 S rRNA and ITS2-based microbial profiling analysis of 60 stool samples from adult individuals. Remarkably, the gut microbiota of H. pylori infected individuals was shown to be increased of members belonging to Succinivibrio, Coriobacteriaceae, Enterococcaceae, and Rikenellaceae. Moreover, gut microbiota of H. pylori infected individuals was shown to have increased abundance of Candida glabrata and other unclassified Fungi. These results links possible role for H. pylori-associated changes in the gut microbiota in intestinal mucosal barrier disruption and early stage colorectal carcinoma deployment. Altogether, the identified differences in bacterial and fungal composition provides important information that may eventually lead to the development of novel biomarkers and more effective management strategies.

Antimicrobial resistance of Helicobacter pylori in Germany, 2015 to 2018

OBJECTIVES

National and international guidelines recommend empiric first-line treatments of individuals infected with Helicobacter pylori without prior antimicrobial susceptibility testing. For this reason, knowledge of primary resistance to first-line antibiotics such as clarithromycin is essential. We assessed the primary resistance of H. pylori in Germany to key antibiotics by molecular genetic methods and evaluated risk factors for the development of resistance.

METHODS

Gastric tissue samples of 1851 yet treatment-naïve H. pylori-positive patients were examined with real-time PCR or PCR and Sanger sequencing for mutations conferring resistance to clarithromycin, levofloxacin and tetracycline. Clinical and epidemiological data were documented and univariable and multivariable logistic regression analyses were conducted.

RESULTS

Overall primary resistances were 11.3% (210/1851) to clarithromycin, and 13.4% (201/1497) to levofloxacin; resistance to tetracycline (2.5%, 38/1497) was as low as combined resistance to clarithromycin/levofloxacin (2.6%, 39/1497). Female sex and prior antimicrobial therapies owing to unrelated bacterial infections were risk factors for clarithromycin resistance (adjusted OR (aOR) 2.3, 95% CI 1.6-3.4; and 2.6, 95% CI 1.5-4.5, respectively); older age was associated with levofloxacin resistance (aOR for those ≥65 years compared with those 18-35 years: 6.6, 95% CI 3.1-14.2).

CONCLUSIONS

Clarithromycin might still be recommended in first-line eradication therapies in yet untreated patients, but as nearly every tenth patient may carry clarithromycin-resistant H. pylori it may be advisable to rule out resistance ahead of treatment by carrying out susceptibility testing or prescribing an alternative therapy.

Differential Helicobacter pylori Plasticity in the Gastric Niche of Subjects at Increased Gastric Cancer Risk

Helicobacter pylori (H. pylori) represents an independent risk factor for Gastric Cancer (GC). First Degree Relatives (FDR) of GC subjects and Autoimmune Gastritis (AG) patients are both at increased risk for GC. H. pylori genetic heterogeneity within the gastric niche of FDR and AG individuals has been little explored. To understand whether they exploit an increased H. pylori stability and virulence, 14 AG, 25 FDR, 39 GC and 13 dyspeptic patients (D) were investigated by a cultural PCR-based approach characterizing single colonies-forming-units. We chose three loci within the Cytotoxin-associated gene-A Pathogenicity Island (CagPAI) (cagA,cagE,virB11), vacA, homA and homB as markers of virulence with reported association to GC. Inflammatory/precancerous lesions were staged according to Sydney System. When compared to D, FDR, similarly to GC patients, were associated to higher atrophy (OR = 6.29; 95% CI:1.23-31.96 in FDR; OR = 7.50; 95% CI:1.67-33.72 in GC) and a lower frequency of mixed infections (OR = 0.16; 95% CI:0.03-0.81 in FDR; OR = 0.10; 95% CI:0.02-0.48 in GC). FDR presented also an increased neutrophil infiltration (OR = 7.19; 95% CI:1.16-44.65). Both FDR and GC carried a higher proportion of CagPAI⁺vacAs1i1mx⁺homB⁺ profiles (OR = 2.71; 95% CI: 1.66-4.41 and OR = 3.43; 95% CI: 2.16-5.44, respectively). Conversely, AG patients presented a lower frequency of subtypes carrying a stable CagPAI and vacAs1i1mx. These results underline different H. pylori plasticity in FDR and AG individuals, and thus, a different host-bacterium interaction capacity that should be considered in the context of eradication therapies.

Syzygium aromaticum L.: Traditional herbal medicine against cagA and vacA toxin genes-producing drug resistant Helicobacter pylori

The Pan-Drug Resistant (PDR), Helicobacter pylori remains an intractable challenge in public health worldwide and this pathogenicity is mainly due to the presence of a cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA). On the other hand, plant extracts such as Syzygium aromaticum contain a diverse array of secondary metabolites, which could be potentially used to combat H. pylori pathogens. To our knowledge, this is the first report on the biomedical potential of S. aromaticum extract against cytotoxin-associated genes producing PDR H. pylori. In this investigation, out of 45 gastric antral biopsy specimens of dyspeptic patients, 20 strains were confirmed as H. pylori. Eight (40%) out of 20 strains were PDR H. pylori while the rest of the strains were Multi-Drug Resistant (MDR) strains. Genotypic analyses of PDR H. pylori strains showed that cagA and vacA genes were found to be 75% and 87.5%, respectively and m2s2 was the most common subtype of vacA gene. S. aromaticum showed a significant higher anti-H. pylori activity compared to that of Cinnamomum zeylanicum and Thymus vulgaris. Eugenol was the major phenolic compound (28.14%) detected in the methanolic extract of S. aromaticum. Clearly, results of the toxicological assessment confirmed the safety of S. aromaticum for use. Hence, these results suggest that S. aromaticum could be a new useful natural antimicrobial agent that could potentially combat cytotoxin genes-producing drug-resistant H. pylori. Moreover, these findings provide a scientific basis for the development of antimicrobial agents from traditional herbal medicines for gastroprotection against gastric ulcer.

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Helicobacter pylori remains an intractable challenge in public health worldwide.

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CagA and VacA genes are H. pylori pathogenicity dependent.

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Eight strains of H. pylori were proven to pan-drug resistant.

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The cagA and vacA genes were found to be 75% and 87.5%, respectively.

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Syzygium aromaticum extract showed a significant higher anti-H. pylori activity.

Effect of environmental salt concentration on the Helicobacter pylori exoproteome

Helicobacter pylori infection and a high salt diet are each risk factors for gastric cancer. In this study, we tested the hypothesis that environmental salt concentration influences the composition of the H. pylori exoproteome. H. pylori was cultured in media containing varying concentrations of sodium chloride, and aliquots were fractionated and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). We identified proteins that were selectively released into the extracellular space, and we identified selectively released proteins that were differentially abundant in culture supernatants, depending on the environmental salt concentration. We also used RNA-seq analysis to identify genes that were differentially expressed in response to environmental salt concentration. The salt-responsive proteins identified by proteomic analysis and salt-responsive genes identified by RNA-seq analysis were mostly non-concordant, but the secreted toxin VacA was salt-responsive in both analyses. Western blot analysis confirmed that VacA levels in the culture supernatant were increased in response to high salt conditions, and quantitative RT-qPCR experiments confirmed that vacA transcription was upregulated in response to high salt conditions. These results indicate that environmental salt concentration influences the composition of the H. pylori exoproteome, which could contribute to the increased risk of gastric cancer associated with a high salt diet. SIGNIFICANCE: Helicobacter pylori-induced alterations in the gastric mucosa have been attributed, at least in part, to the actions of secreted H. pylori proteins. In this study, we show that H. pylori growth in high salt concentrations leads to increased levels of a secreted VacA toxin. Salt-induced alterations in the composition of the H. pylori exoproteome is relevant to the increased risk of gastric cancer associated with consumption of a high salt diet.

Multifaceted Roles of microRNAs in Host-Bacterial Pathogen Interaction

MicroRNAs (miRNAs) are a well-characterized class of small noncoding RNAs that act as major posttranscriptional regulators of gene expression. Accordingly, miRNAs have been associated with a wide range of fundamental biological processes and implicated in human diseases. During the past decade, miRNAs have also been recognized for their role in the complex interplay between the host and bacterial pathogens, either as part of the host response to counteract infection or as a molecular strategy employed by bacteria to subvert host pathways for their own benefit. Importantly, the characterization of downstream miRNA targets and their underlying mechanisms of action has uncovered novel molecular factors and pathways relevant to infection. In this article, we review the current knowledge of the miRNA response to bacterial infection, focusing on different bacterial pathogens, including Salmonella enterica, Listeria monocytogenes, Mycobacterium spp., and Helicobacter pylori, among others.

Microbial evolutionary medicine: from theory to clinical practice

Medicine and clinical microbiology have traditionally attempted to identify and eliminate the agents that cause disease. However, this traditional approach is becoming inadequate for dealing with a changing disease landscape. Major challenges to human health are non-communicable chronic diseases, often driven by altered immunity and inflammation, and communicable infections from agents which harbour antibiotic resistance. This Review focuses on the so-called evolutionary medicine framework, to study how microbial communities influence human health. The evolutionary medicine framework aims to predict and manipulate microbial effects on human health by integrating ecology, evolutionary biology, microbiology, bioinformatics, and clinical expertise. We focus on the potential of evolutionary medicine to address three key challenges: detecting microbial transmission, predicting antimicrobial resistance, and understanding microbe-microbe and human-microbe interactions in health and disease, in the context of the microbiome.

Interaction studies on bacterial stringent response protein RelA with uncharged tRNA provide evidence for its prerequisite complex for ribosome binding

The bacterial stringent response is regulated by the synthesis of (p)ppGpp which is mediated by RelA in a complex with uncharged tRNA and ribosome. We intended to probe RelA-uncharged tRNA interactions off the ribosome to understand the sequential activation mechanism of RelA. Stringent response is a key regulatory pleiotropic mechanism which allows bacteria to survive in unfavorable conditions. Since the discovery of RelA, it has been believed that it is activated upon binding to ribosomes which already have uncharged tRNA on acceptor site (A-site). However, uncharged tRNA occupied in the A-site of the ribosome prior to RelA binding could not be observed; therefore, recently an alternate model for RelA activation has been proposed in which RelA first binds to uncharged tRNA and then RelA-uncharged tRNA complex is loaded on to the ribosome to synthesize (p)ppGpp. To explore the alternate hypothesis, we report here the in vitro binding of uncharged tRNA to RelA in the absence of ribosome using formaldehyde cross-linking, fluorescence spectroscopy, surface plasmon resonance, size-exclusion chromatography, and hydrogen-deuterium exchange mass spectrometry. Altogether, our results clearly indicate binding between RelA and uncharged tRNA without the involvement of ribosome. Moreover, we have analyzed their binding kinetics and mapping of tRNA-interacting regions of RelA structure. We have also co-purified TGS domain in complex with tRNA to further establish in vivo RelA-tRNA binding. We have observed that TGS domain recognizes all types of uncharged tRNA similar to EF-Tu and tRNA interactions. Altogether, our results demonstrate the complex formation between RelA and uncharged tRNA that may be loaded to the ribosome for (p)ppGpp synthesis.

Prevalence of Helicobacter pylori and Its Associated Factors among Healthy Asymptomatic Residents in the United Arab Emirates

The United Arab Emirates (UAE) has been under continuous populational influences from Asia, Europe, and Africa, making it an ideal site for epidemiological studies on Helicobacter pylori. However, there has been a paucity of well-designed prevalence studies on H. pylori from UAE. The aim of this study was to determine the prevalence of H. pylori and its associated risk factors in the UAE. A prospective cross-sectional study was conducted on healthy asymptomatic residents of UAE. Socio-demographic, lifestyle, and gastrointestinal characteristics of participants were obtained through a questionnaire in parallel within the stool sample collection. A total of 350 participants were included in this study and were tested for H. pylori using the stool antigen test (Premier Platinum HpSAT). Out of the total tested study participants, 41% were found to be H. pylori-infected. Logistic regression analysis has shown a significant association between H. pylori infection and gender, age, ethnicity, profession, domestic overcrowding, source of drinking water, and gastrointestinal characteristics of participants. Based on the results from this study, we suggest that preventive measures against H. pylori infection should be considered worthy by public health authorities.

A Novel Gastric Spheroid Co-culture Model Reveals Chemokine-Dependent Recruitment of Human Dendritic Cells to the Gastric Epithelium

BACKGROUND & AIMS

Gastric dendritic cells (DCs) control the adaptive response to infection with Helicobacter pylori, a major risk factor for peptic ulcer disease and gastric cancer. We hypothesize that DC interactions with the gastric epithelium position gastric DCs for uptake of luminal H pylori and promote DC responses to epithelial-derived mediators. The aim of this study was to determine whether the gastric epithelium actively recruits DCs using a novel co-culture model of human gastric epithelial spheroids and monocyte-derived DCs.

METHODS

Spheroid cultures of primary gastric epithelial cells were infected with H pylori by microinjection. Co-cultures were established by adding human monocyte-derived DCs to the spheroid cultures and were analyzed for DC recruitment and antigen uptake by confocal microscopy. Protein array, gene expression polymerase chain reaction array, and chemotaxis assays were used to identify epithelial-derived chemotactic factors that attract DCs. Data from the co-culture model were confirmed using human gastric tissue samples.

RESULTS

Human monocyte-derived DCs co-cultured with gastric spheroids spontaneously migrated to the gastric epithelium, established tight interactions with the epithelial cells, and phagocytosed luminally applied H pylori. DC recruitment was increased upon H pylori infection of the spheroids and involved the activity of multiple chemokines including CXCL1, CXCL16, CXCL17, and CCL20. Enhanced chemokine expression and DC recruitment to the gastric epithelium also was observed in H pylori-infected human gastric tissue samples.

CONCLUSIONS

Our results indicate that the gastric epithelium actively recruits DCs for immunosurveillance and pathogen sampling through chemokine-dependent mechanisms, with increased recruitment upon active H pylori infection.

Inhibitory Effects of Menadione on Helicobacter pylori Growth and Helicobacter pylori-Induced Inflammation via NF-κB Inhibition

H. pylori is classified as a group I carcinogen by WHO because of its involvement in gastric cancer development. Several reports have suggested anti-bacterial effects of menadione, although the effect of menadione on major virulence factors of H. pylori and H. pylori-induced inflammation is yet to be elucidated. In this study, therefore, we demonstrated that menadione has anti-H. pylori and anti-inflammatory effects. Menadione inhibited growth of H. pylori reference strains and clinical isolates. Menadione reduced expression of vacA in H. pylori, and translocation of VacA protein into AGS (gastric adenocarcinoma cell) was also decreased by menadione treatment. This result was concordant with decreased apoptosis in AGS cells infected with H. pylori. Moreover, cytotoxin-associated protein A (CagA) translocation into H. pylori-infected AGS cells was also decreased by menadione. Menadione inhibited expression of several type IV secretion system (T4SS) components, including virB2, virB7, virB8, and virB10, that are responsible for translocation of CagA into host cells. In particular, menadione inhibited nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) activation and thereby reduced expression of the proinflammatory cytokines such as IL-1β, IL-6, IL-8, and TNF-α in AGS as well as in THP-1 (monocytic leukemia cell) cell lines. Collectively, these results suggest the anti-bacterial and anti-inflammatory effects of menadione against H. pylori.

Protein changes in gastric epithelial cells RGM-1 in response to Helicobacter pylori infection

Helicobacter pylori-induced inflammation significantly increases the risk of gastric cancer. To investigate the role of H. pylori infection in gastric epithelial cell carcinogenesis, flow cytometry was used to analyze the apoptosis of gastric epithelial cells infected by H. pylori. Next, LTQ MS mass spectrometry (MS) was applied to identify protein changes in gastric epithelial cells infected with H. pylori, and then bioinformatics was adopted to analyze the cellular localization and biological function of differential proteins. LTQ MS/MS successfully identified identified 22 differential proteins successfully, including 20 host-cell proteins and two H. pylori bacterial proteins. Also, human proteins were located in all areas of cells and involved in various cell biological functions. The oncogene proteins p53, p16, and C-erbB-2 proteins in H. pylori-infected RGM-1 cells were remarkably increased from the analysis by Western blot analysis. H. pylori infection of gastric epithelial cells leads to changes in various protein components in the cell, and enhances the expression of oncogene proteins, thereby increasing the possibility of possibility of carcinogenesis of H. pylori infection.

Helicobacter pylori-induced DNA Methylation as an Epigenetic Modulator of Gastric Cancer: Recent Outcomes and Future Direction

Gastric cancer is ranked fifth in cancer list and has the third highest mortality rate. Helicobacter pylori is a class I carcinogen and a predominant etiological factor of gastric cancer. H. pylori infection may induce carcinogenesis via epigenetic alterations in the promoter region of various genes. H. pylori is known to induce hypermethylation-silencing of several tumor suppressor genes in H. pylori-infected cancerous and H. pylori-infected non-cancerous gastric mucosae. This article presents a review of the published literature mainly from the last year 15 years. The topic focuses on H. pylori-induced DNA methylation linked to gastric cancer development. The authors have used MeSH terms "Helicobacter pylori" with "epigenetic," "DNA methylation," in combination with "gastric inflammation", gastritis" and "gastric cancer" to search SCOPUS, PubMed, Ovid, and Web of Science databases. The success of epigenetic drugs such as de-methylating agents in the treatment of certain cancers has led towards new prospects that similar approaches could also be applied against gastric cancer. However, it is very important to understand the role of all the genes that have already been linked to H. pylori-induced DNA methylation in order to in order to evaluate the potential benefits of epigenetic drugs.

Role of a Stem-Loop Structure in Helicobacter pylori cagA Transcript Stability

Helicobacter pylori CagA is a secreted effector protein that contributes to gastric carcinogenesis. Previous studies showed that there is variation among H. pylori strains in the steady-state levels of CagA and that a strain-specific motif downstream of the cagA transcriptional start site (the +59 motif) is associated with both high levels of CagA and premalignant gastric histology. The cagA 5' untranslated region contains a predicted stem-loop-forming structure adjacent to the +59 motif. In the current study, we investigated the effect of the +59 motif and the adjacent stem-loop on cagA transcript levels and cagA mRNA stability. Using site-directed mutagenesis, we found that mutations predicted to disrupt the stem-loop structure resulted in decreased steady-state levels of both the cagA transcript and the CagA protein. Additionally, these mutations resulted in a decreased cagA mRNA half-life. Mutagenesis of the +59 motif without altering the stem-loop structure resulted in reduced steady-state cagA transcript and CagA protein levels but did not affect cagA transcript stability. cagA transcript stability was not affected by increased sodium chloride concentrations, an environmental factor known to augment cagA transcript levels and CagA protein levels. These results indicate that both a predicted stem-loop structure and a strain-specific +59 motif in the cagA 5' untranslated region influence the levels of cagA expression.

Vonoprazan-Based Third-Line Therapy Has a Higher Eradication Rate against Sitafloxacin-Resistant Helicobacter pylori

Eradication of Helicobacter pylori (H. pylori) is an effective strategy for preventing various gastrointestinal diseases such as gastric cancer and mucosa-associated lymphoid tissue (MALT) lymphoma. However, the eradication success rate is decreasing because of a recent increase in drug-resistant strains of H. pylori. Here, we evaluated the success rate of eradication therapy with vonoprazan (VPZ), a new potassium-competitive acid blocker, against drug-resistant H. pylori. In total, 793 patients who received H. pylori eradication therapy were investigated retrospectively. All underwent esomeprazole (EPZ)-based triple therapy (n = 386) or VPZ-based triple therapy (n = 407) for first-, second- and third-line H. pylori eradication for 7 days. The overall success rates of first- and third-line H. pylori eradication were significantly higher for VPZ-based triple therapy (88.4% and 93.0%, respectively, per protocol (PP)) than for EPZ-based triple therapy (69.5% and 56.5%, respectively, PP). Moreover, the success rates of first- and third-line eradication of clarithromycin (CLR)- and sitafloxacin (STFX)-resistant H. pylori were significantly higher for VPZ-based triple therapy (72.0% and 91.7%, PP) than for EPZ-based triple therapy (38.5% and 20.0%, PP). In addition, patient age did not affect the eradication rate of VPZ-based first-line therapy, whereas the success rate of EPZ-based therapy was lower in patients under 65 years of age. Our results clearly demonstrated that VPZ-based therapy achieved a higher eradication rate even against CLR- and STFX-resistant H. pylori, and that patient age did not affect the eradication rate of VPZ-based therapy. These findings suggest that dual therapy using VPZ and amoxicillin may be sufficient for standard H. pylori eradication, and may thus also be beneficial for avoiding antibiotic misuse.

oipA "on" status of Helicobacter pylori is associated with gastric cancer in North-Eastern Brazil

Background

Although, outer membrane protein OipA of Helicobacter pylori has been associated with gastric mucosal damage and gastroduodenal diseases, studies evaluating gastric cancer patients are scarce. We investigated whether the functional oipA “on” status was associated with gastric cancer in the North-eastern Brazil, region with high prevalence of gastric cancer.

Methods

We included samples from 95 H. pylori positive subjects (23 patients with gastritis, 24 with gastric cancer, 32 first-degree relatives of gastric cancer patients and 16 children). oipA was assayed by polymerase chain reaction (PCR) and DNA sequencing. cagA and vacA status were evaluated by PCR.

Results

Overall 81.1% of the H. pylori strains had functional oipA. In adults, the oipA “on” status (OR = 9.20; 95%CI = 1.45–58.48, P = 0.02) and increasing age (OR = 1.08; 95%CI = 1.03–1.14; P = 0.003) were independently associated with gastric cancer in a logistic model. The oipA “on” status (OR = 14.75; 95%CI: 2.53–86.13, P = 0.003) was also associated with first-degree relatives of gastric cancer patients when compared with gastritis. The frequency of oipA “on” status did not differ between children and adults (P = 0.87). The oipA “on” status was significantly correlated with the presence of cagA and vacA s1 m1.

Conclusion

oipA “on” status was independently associated with gastric cancer and first-degree relatives of gastric cancer patients in North-eastern Brazil.

The Contribution of Drugs and Helicobacter pylori to Gastric Mucosa Changes in Patients with Systemic Lupus Erythematosus and Antiphospholipid Syndrome

BACKGROUND

The nature and rate of gastric mucosal (GM) damage in systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) remain to be among the unsolved problems.

OBJECTIVE

To define the role of H. pylori and drugs in the development of GM damages in SLE and APS.

METHODS

A study was conducted on 85 patients with SLE and APS. All the patients underwent esophagogastroduodenoscopy with targeted biopsy of the mucosa of the gastric body and antrum. The presence of H. pylori in the gastric biopsy specimens was determined using polymerase chain reaction.

RESULTS

Endoscopic examination revealed that the patients with SLE and APS on admission had the following GM changes: antral gastritis (82.4%), erosions (24.7%), hemorrhages (8.2%), and pangastritis (8.2%). SLE and APS patients showed no direct correlation between the found GM damages and the presence of H. pylori. The use of glucocorticoid, low-dose acetylsalicylic acid, nonsteroidal anti-inflammatory drug, and anticoagulant in SLE and APS patients is accompanied by GM damage.

CONCLUSION

There was no evidence of the role of H. pylori in GM damage in the SLE and APS patients. More frequent detection of H. pylori was observed in anticoagulants or low-dose acetylsalicylic acid users than in glucocorticoids and nonsteroidal anti-inflammatory drugs ones.

Exploring the impact of Helicobacter pylori on gut microbiome composition

Helicobacter pylori (H. pylori) is known to colonize gastric mucosa, induce inflammation, and alter gastric microbiota resulting in a spectrum of gastric diseases. Likewise, changes in gut microbiota have recently been linked with various metabolic and inflammatory diseases. While extensive number of studies were published examining the relationship between H. pylori and gastric microbiota, little is known about the impact of H. pylori on downstream gut microbiota. In this study, we performed 16 S rRNA and ITS2-based microbial profiling analysis of 60 stool samples from adult individuals. Remarkably, the gut microbiota of H. pylori infected individuals was shown to be increased of members belonging to Succinivibrio, Coriobacteriaceae, Enterococcaceae, and Rikenellaceae. Moreover, gut microbiota of H. pylori infected individuals was shown to have increased abundance of Candida glabrata and other unclassified Fungi. These results links possible role for H. pylori-associated changes in the gut microbiota in intestinal mucosal barrier disruption and early stage colorectal carcinoma deployment. Altogether, the identified differences in bacterial and fungal composition provides important information that may eventually lead to the development of novel biomarkers and more effective management strategies.

Sero-prevalence of Helicobacter pylori CagA immunoglobulin G antibody, serum pepsinogens and haemoglobin levels in adults

Associations observed of Helicobacter pylori infection with haemoglobin levels are inconsistent. We examined associations of H. pylori sero-prevalence and serum pepsinogens (PGs), as non-invasive markers of atrophic gastritis, with haemoglobin levels. A cross-sectional study was undertaken among 654 Jewish and 937 Arab residents of Jerusalem, aged 25–78 years, randomly selected from Israel’s national population registry in age-sex and population strata. Sera were tested for H. pylori IgG, cytotoxin–associated gene A (CagA) antigen IgG antibody and PGs levels. Multivariable models were fitted to account for confounders. Participants with atrophic gastritis (PGI < 30 μg/L or a PGI: PGII < 3.0) had lower haemoglobin levels than those without: beta-coefficient −0.34 (95% CI −0.59, −0.09); in men −0.27 (95% CI −0.67, 0.12), and in women −0.43 (95% CI −0.74, −0.12). Lower haemoglobin levels were noted in persons with CagA antibody than in those H. pylori sero-negative or H. pylori-CagA sero-negative: beta-coefficient −0.14 (95% CI −0.29, 0.01). Anaemia was more common among women and men with than without atrophic gastritis: adjusted OR 2.58 (95% CI 1.48, 4.48) and 1.52 (95% CI 0.59, 3.95), respectively. In conclusion, independent of known correlates, atrophic gastritis and apparently CagA sero-positivity, a marker of H. pylori virulent strains, are associated with lower haemoglobin levels.

Helicobacter pylori Infection and Its Risk Factors: A Prospective Cross-Sectional Study in Resource-Limited Settings of Northwest Ethiopia

Background

Helicobacter pylori (H. pylori) is implicated for the causation of gastrointestinal tract infections including gastric cancer. Although the infection is prevalent globally, the impact is immense in countries with poor environmental and socioeconomic status including Ethiopia. Epidemiological study on the magnitude of H. pylori and possible risk factors has priceless implication. Therefore, in this study, we determined the prevalence and risk factors of H. pylori infection in the resource-limited area of northwest Ethiopia.

Methods

A prospective cross-sectional study was conducted on northwest Ethiopia among 201 systematically selected dyspeptic patients. Data were collected using a structured and pretested questionnaire, and stool and serum samples were collected and analyzed by SD BIOLINE H. pylori Ag and dBest H. pylori Disk tests, respectively. Chi-square test was performed to see association between variables, and binary and multinomial regression tests were performed to identify potential risk factors. P values <0.05 were taken statistically significant.

Result

Prevalence of H. pylori was found to be 71.1% (143/201) and 37.3% (75/201) using the dBest H. pylori Test Disk and SD BIOLINE H. pylori Ag test, respectively. H. pylori seropositivity, using dBest H. pylori Disk tests, is significantly associated in age groups <10 years (P=0.044) and married patients (P=0.016). In those patients with H. pylori (a positive result with either the Ab or Ag test), drinking water from well sources had 2.23 times risk of getting H. pylori infection (P=0.017), and drinking coffee (1.51 (0.79–2.96, P=0.025)) and chat chewing (1.78 (1.02–3.46, P=0.008) are the common risk factors.

Conclusion

The present study discovered considerable magnitude of H. pylori among the dyspeptic patients in the study area. H. pylori infection is frequent in individuals drinking water from well sources, and thus, poor sanitation and unhygienic water supply are contributing factors. Policies aiming at improving the socioeconomic status will reduce potential sources of infection, transmission, and ultimately the prevalence and incidence of H. pylori.

Linking traditional anti-ulcer use of rhizomes of Bergenia ciliata (Haw.) to its anti-Helicobacter pylori constituents

The rhizomes of Bergenia ciliata (B. ciliata, Family: Saxifragaceae) are widely used for treating gastric ulcers in folk medicine in Asia. It was hypothesized that anti-ulcer activity of B. ciliata is due to its anti-Helicobacter pylori (H. pylori) activity. The anti-H. pylori activity was investigated on six clinical bacterial isolates using agar well-diffusion and broth micro-dilution methods. The anti-H. pylori activity of amoxicillin (standard) was the highest (Zone of inhibition; ZI = 25 mm, minimum inhibitory concentration; MIC=0.125 µg/µL) whereas among all the extracts of the rhizomes, methanol extract showed the highest activity (ZI = 16 mm, MIC = 12.50 µg/µL). Bioassay guided isolation of methanol extract using chromatographic and crystallization techniques isolated bergenin (ZI = 21mm, MIC = 0.391µg/µL) as constituent responsible for anti-H. pylori activity. The present study describes for the first time anti-H. pylori activity and possible mechanism of anti-ulcer properties of rhizomes of B. ciliata.

Helicobacter pylori infection and liver diseases: Epidemiology and insights into pathogenesis

Both Helicobacter pylori (H. pylori) infection and liver diseases, including nonalcoholic fatty liver disease (NAFLD), viral hepatitis, and hepatocellular carcinoma (HCC), have high prevalences worldwide, and the relationship between H. pylori infection and liver disease has been discussed for many years. Although positive correlations between H. pylori and NAFLD have been identified in some clinical and experimental studies, negative correlations have also been obtained in high-quality clinical studies. Associations between H. pylori and the pathogenesis of chronic viral hepatitis, mainly disease progression with fibrosis, have also been suggested in some clinical studies. Concerning HCC, a possible role for H. pylori in hepatocarcinogenesis has been identified since H. pylori genes have frequently been detected in resected HCC specimens. However, no study has revealed the direct involvement of H. pylori in promoting the development of HCC. Although findings regarding the correlations between H. pylori and liver disease pathogenesis have been accumulating, the existing data do not completely lead to an unequivocal conclusion. Further high-quality clinical and experimental analyses are necessary to evaluate the efficacy of H. pylori eradication in ameliorating the histopathological changes observed in each liver disease.

The Probiotic Lactobacillus rhamnosus for Alleviation of Helicobacter pylori-Associated Gastric Pathology in East Africa

The probiotic Lactobacillus rhamnosus GG (LGG) can play a role in establishing a harmless relationship with Helicobacter pylori and reduce gastric pathology in East African populations. H. pylori has the ability to inhabit the surface of the mucous layer of the human stomach and duodenum. In the developing world, an estimated 51% of the population is carrier of H. pylori, while in some Western countries these numbers dropped below 20%, which is probably associated with improved sanitation and smaller family sizes. Colonization by H. pylori can be followed by inflammation of the gastric mucus layer, and is a risk factor in the development of atrophic gastritis, peptic ulcers and gastric cancer. Notwithstanding the higher prevalence of H. pylori carriers in developing countries, no equal overall increase in gastric pathology is found. This has been attributed to a less pro-inflammatory immune response to H. pylori in African compared to Caucasian populations. In addition, a relatively low exposure to other risk factors in certain African populations may play a role, including the use of non-steroidal anti-inflammatory drugs, smoking, and diets without certain protective factors. A novel approach to the reduction of H. pylori associated gastric pathology is found in the administration of the probiotic bacterium Lactobacillus rhamnosus yoba 2012 (LRY), the generic variant of LGG. This gastro-intestinal isolate inhibits H. pylori by competition for substrate and binding sites as well as production of antimicrobial compounds such as lactic acid. In addition, it attenuates the host's H. pylori-induced apoptosis and inflammation responses and stimulates angiogenesis in the gastric and duodenal epithelium. The probiotic LRY is not able to eradicate H. pylori completely, but its co-supplementation in antibiotic eradication therapy has been shown to relieve side effects of this therapy. In Uganda, unlike other African countries, gastric pathology is relatively common, presumably resulting from the lack of dietary protective factors in the traditional diet. Supplementation with LRY through local production of probiotic yogurt, could be a solution to establish a harmless relationship with H. pylori and reduce gastric pathology and subsequent eradication therapy treatment.

Chronic Gastritis Due to Helicobacter Pylori Associated with Increased Serum Levels of CA54/61: A Report of Three Cases

BACKGROUND The bacterial pathogen Helicobacter pylori (H. pylori) can cause chronic gastritis. CA54/61 is a serum tumor marker that has been shown to be positive in the several types of human malignancy. However, the association of between chronic gastritis due to H. pylori and elevated serum levels of CA54/61 has not been previously reported. This report is of three cases of increased serum levels of CA54/61 associated with H. pylori chronic gastritis. CASE REPORT Case 1 was a 44-year-old Japanese woman with a serum CA54/61 level of 138 U/ml (normal level: 12 U/ml). Following treatment and eradication of H. pylori the serum CA54/61 level decreased to 14 U/ml. Case 2 was a 73-year-old Japanese man with a serum level of less than 2 U/ml before completion of successful eradication therapy of H. pylori with a small peak of 30 U/ml after therapy. Case 3 was a 54-year-old Japanese man who maintained a serum CA54/61 level of approximately 20 U/ml before and until 603 days after eradication therapy. None of the three patients had malignancy, which is usually suggested by this serum marker. CONCLUSIONS These three case reports suggest the possibility of an association between chronic gastritis involving H. pylori infection and an elevated serum level of CA54/61. It is possible that the inflammatory gastric mucosal cells supply CA54/61 to the bloodstream. However, further studies are required to confirm the association between serum levels of CA54/61 and H. pylori chronic gastritis and the underlying mechanisms of this association.

Retrospective study on outcome of salvage Helicobacter pylori eradication therapies based on molecular genetic susceptibility testing

BACKGROUND

Antimicrobial susceptibility of Helicobacter (H.) pylori is usually determined by phenotypic methods. When H. pylori cannot be grown owing to contaminations or delay in transport of gastric tissue samples to the microbiological laboratory, molecular genetic testing is a reasonable alternative. The aim of this retrospective study was to assess the outcome of salvage eradication treatments based on molecular genetic susceptibility testing.

METHODS

Data on 144 H. pylori PCR-positive gastric tissue samples of patients primarily with prior unsuccessful eradication treatments were retrospectively analyzed. Eradication treatments were recommended based on genotypic clarithromycin and/or levofloxacin susceptibility as tested by real-time PCR or reverse hybridization. Treatment success was assessed by attending physicians using urea breath test; stool-antigen ELISA; and microbiology/histopathology.

RESULTS

Overall success rate of molecular genetic testing-guided salvage treatments was low (68%); none of the regimens chosen was significantly better than another. Multivariable logistic regression analysis did not reveal any factors that may predict treatment failure.

CONCLUSIONS

Eradication success was poor despite susceptibility testing. Gastroenterologists are advised to prescribe recommended salvage treatments, considering recommended dosages and prolonged treatment duration.

Feco-prevalence and risk factors of Helicobacter pylori infection among symptomatic patients at Dessie Referral Hospital, Ethiopia

BACKGROUND

Helicobacter pylori (H. pylori) infection is the most common chronic bacterial infection in the world. It can result in various upper gastroduodenal diseases. The prevalence varies among countries, population groups within the same country and testing methods. The aim of the study was to determine feco-prevalence and risk factors of H.pylori infection among symptomatic patients in Amhara region, Northeast Ethiopia.

METHODS

A cross sectional study was conducted in a total of 342 new consecutive outpatients with upper abdominal complaints at Dessie Referral Hospital from May to July, 2016. A structured questionnaire was used to collect the socio-demographic, lifestyle and environmental data. Stool samples were used to detect H. pylori specific antigen. Blood samples were assessed for anti-H. pylori IgG and ABO blood types. SPSS version 20.0 statistical software package was used for data analysis. Chi-square test and logistic regression were used in the analysis and P-value ≤0.05 was considered as statistically significant.

RESULTS

H. pylori stool antigen and serum anti-H.pylori IgG detection rate was 30.4 and 60.5% respectively with kappa measure of agreement of 0.271. Antigen detection was significantly associated with family size (> 3) [AOR = 1.83, 95% CI: 1.10-3.05, p = 0.02], more persons (> 3) sharing the same bed room in the household [AOR = 2.91, 95% CI: 1.39-6.11, p = 0.005], alcohol consumption (> once a week) [AOR = 2.70, 95% CI: 1.49-4.89, p = 0.001] and individuals' blood type: group O [AOR = 8.93, 95%CI: 1.79-44.48, p = 0.008] and group A [AOR = 5.53, 95%CI: 1.08-28.36, p = 0.040]. Gender, age, marital status, occupation, educational level, residence, smoking as well as coffee, tea, fruits and vegetables consumption were not statistically associated with H. pylori antigen detection (p > 0.05).

CONCLUSION

The overall H. pylori stool antigen and anti-H. pylori IgG detection rate was 30.4 and 60.5%, respectively. The test agreement was not strongly convincing and needs further evaluation. Alcohol consumption, overcrowding and ABO blood group were significantly associated with H. pylori antigen detection.

miRNAs reshape immunity and inflammatory responses in bacterial infection

Pathogenic bacteria cause various infections worldwide, especially in immunocompromised and other susceptible individuals, and are also associated with high infant mortality rates in developing countries. MicroRNAs (miRNAs), small non-coding RNAs with evolutionarily conserved sequences, are expressed in various tissues and cells that play key part in various physiological and pathologic processes. Increasing evidence implies roles for miRNAs in bacterial infectious diseases by modulating inflammatory responses, cell penetration, tissue remodeling, and innate and adaptive immunity. This review highlights some recent intriguing findings, ranging from the correlation between aberrant expression of miRNAs with bacterial infection progression to their profound impact on host immune responses. Harnessing of dysregulated miRNAs in bacterial infection may be an approach to improving the diagnosis, prevention and therapy of infectious diseases.

Changes in production of tiny cellular RNAs in response to bacterial infection could guide the development of better diagnostics and therapies. MicroRNAs regulate other genes by binding to messenger RNA strands and controlling their translation into proteins. Xikun Zhou, Min Wu and colleagues of the University of North Dakota have now reviewed current knowledge about how microRNA levels shift during infection with various bacterial pathogens. These microRNAs can modulate the immune response as well as pathways that influence metabolic activity and cell survival. Increasing studies have indicated that shifts in microRNA levels in response to different infections could provide a potential bacterial ‘fingerprint’ for achieving accurate diagnosis. With deeper insight into how different microRNAs influence infection, it might one day day become possible to target these molecules with ‘antisense’ or ‘agonist’ drugs that modulate their activity.

Helicobacter pylori genetic diversification in the Mongolian gerbil model

Helicobacter pylori requires genetic agility to infect new hosts and establish long-term colonization of changing gastric environments. In this study, we analyzed H. pylori genetic adaptation in the Mongolian gerbil model. This model is of particular interest because H. pylori-infected gerbils develop a high level of gastric inflammation and often develop gastric adenocarcinoma or gastric ulceration. We analyzed the whole genome sequences of H. pylori strains cultured from experimentally infected gerbils, in comparison to the genome sequence of the input strain. The mean annualized single nucleotide polymorphism (SNP) rate per site was 1.5e⁻⁵, which is similar to the rates detected previously in H. pylori-infected humans. Many of the mutations occurred within or upstream of genes associated with iron-related functions (fur, tonB1, fecA2, fecA3, and frpB3) or encoding outer membrane proteins (alpA, oipA, fecA2, fecA3, frpB3 and cagY). Most of the SNPs within coding regions (86%) were non-synonymous mutations. Several deletion or insertion mutations led to disruption of open reading frames, suggesting that the corresponding gene products are not required or are deleterious during chronic H. pylori colonization of the gerbil stomach. Five variants (three SNPs and two deletions) were detected in isolates from multiple animals, which suggests that these mutations conferred a selective advantage. One of the mutations (FurR88H) detected in isolates from multiple animals was previously shown to confer increased resistance to oxidative stress, and we now show that this SNP also confers a survival advantage when H. pylori is co-cultured with neutrophils. Collectively, these analyses allow the identification of mutations that are positively selected during H. pylori colonization of the gerbil model.

Association between Fusobacterium nucleatum and colorectal cancer: Progress and future directions

The initiation and progression of colorectal cancer (CRC) involves genetic and epigenetic alterations influenced by dietary and environmental factors. Increasing evidence has linked the intestinal microbiota and colorectal cancer. More recently, Fusobacterium nucleatum (Fn), an opportunistic commensal anaerobe in the oral cavity, has been associated with CRC. Several research teams have reported an overabundance of Fn in human CRC and have elucidated the possible mechanisms by which Fn is involved in colorectal carcinogenesis in vitro and in mouse models. However, the mechanisms by which Fn promotes colorectal carcinogenesis remain unclear. To provide new perspectives for early diagnosis, the identification of high risk populations and treatment for colorectal cancer, this review will summarize the relative research progresses regarding the relationship between Fn and colorectal cancer.

Distribution and clinical associations of integrating conjugative elements and cag pathogenicity islands of Helicobacter pylori in Indonesia

The clinical associations and correlations with other virulence factors such as cag pathogenicity island (PAI) of the Integrating Conjugative Elements Helicobacter pylori TFSS (ICEHptfs), a new type IV secretion system (TFSS) in H. pylori has not been described. Among 103 studied strains from Indonesia, almost all strains (99.0%) contained cag PAI with more than half (55.8%) were intact cag PAI. Patients infected with intact cag PAI strains showed significantly higher antral activity, inflammation and atrophy as well as corporal inflammation than those with non-intact cag PAI strains, confirming the virulence of cag PAI. Over half of strains (53.8%) contained ICEHptfs, predominantly consisted of ICEHptfs3-tfs4a (42.8%) and ICEHptfs3 (16.3%). Although patients infected with ICEHptfs-positive strains had lower H. pylori density, those with the complete ICEHptfs4b strains tended to have higher antral activity than the negative one. In combination, patients infected with combination of intact cag PAI-ICEHptfs-positive strains had more severe inflammation than those with non-intact cag PAI-ICEHptfs-negative, suggesting a possibility of a mutual correlation between these TFSS(s).

High-Salt Conditions Alter Transcription of Helicobacter pylori Genes Encoding Outer Membrane Proteins

Helicobacter pylori infection and high dietary salt intake are risk factors for the development of gastric adenocarcinoma. One possible mechanism by which a high-salt diet could influence gastric cancer risk is by modulating H. pylori gene expression. In this study, we utilized transcriptome sequencing (RNA-seq) methodology to compare the transcriptional profiles of H. pylori grown in media containing different concentrations of sodium chloride. We identified 118 differentially expressed genes (65 upregulated and 53 downregulated in response to high-salt conditions), including multiple members of 14 operons. Twenty-nine of the differentially expressed genes encode proteins previously shown to undergo salt-responsive changes in abundance, based on proteomic analyses. Real-time reverse transcription (RT)-PCR analyses validated differential expression of multiple genes encoding outer membrane proteins, including adhesins (SabA and HopQ) and proteins involved in iron acquisition (FecA2 and FecA3). Transcript levels of sabA, hopA, and hopQ are increased under high-salt conditions, whereas transcript levels of fecA2 and fecA3 are decreased under high-salt conditions. Transcription of sabA, hopA, hopQ, and fecA3 is derepressed in an arsS mutant strain, but salt-responsive transcription of these genes is not mediated by the ArsRS two-component system, and the CrdRS and FlgRS two-component systems do not have any detectable effects on transcription of these genes. In summary, these data provide a comprehensive view of H. pylori transcriptional alterations that occur in response to high-salt environmental conditions.

Detection of Helicobacter pylori in stool samples of young children using real-time polymerase chain reaction

BACKGROUND

The aims of this study were to develop and validate a multiplex real-time polymerase chain reaction (q-PCR) assay of Helicobacter pylori in stool samples of healthy children. Additionally, we determined the prevalence of clarithromycin resistance and cagA gene in H. pylori-positive samples.

MATERIALS AND METHODS

Archived stool samples from 188 children aged 6-9 years and 272 samples of 92 infants aged 2-18 months were tested for H. pylori antigens using enzyme immunoassay (EIA). A multiplex q-PCR assay was designed to detect H. pylori 16S rRNA and urease and the human RNase P gene as an internal control. Kappa coefficient was calculated to assess the agreement between q-PCR and EIA.

RESULTS

Laboratory validation of the q-PCR assay using quantitated H. pylori ATCC 43504 extracted DNA showed S-shaped amplification curves for all genes; the limit of detection was 1 CFU/reaction. No cross-reactivity with other bacterial pathogens was noted. Applying the multiplex q-PCR to DNA extracted from fecal samples showed clear amplification curves for urease gene, but not for 16S rRNA. The prevalence of H. pylori infection was 50% (95% CI 43%-57%) by q-PCR (urease cycle threshold <44) vs 59% (95% CI 52%-66%) by EIA. Kappa coefficient was .80 (P < .001) and .44 (P < .001) for children aged 6-9 years and 2-18 months, respectively. Sixteen samples were positive for cagA and three were positive for clarithromycin resistance mutation (A2143G) as confirmed by sequencing.

CONCLUSIONS

The developed q-PCR can be used as a cotechnique to enhance the accuracy of H. pylori detection in epidemiological studies and in clinical settings.

Point Mutations at gyrA and gyrB Genes of Levofloxacin-Resistant Helicobacter pylori Isolates in the Esophageal Mucosa from a Venezuelan Population

The treatment of Helicobacter pylori infection is complicated by antibiotic resistance. A high levofloxacin (LVX) resistance rate was previously demonstrated in H. pylori isolates from gastric mucosa (40%) and esophagus (19%) in individual hosts of a Venezuelan population. We aimed to assess the molecular mechanisms of LVX resistance and susceptibility in isolates from the gastroesophageal mucosa, by studying point mutations in the quinolone resistance-determining region of gyrA and gyrB genes. Sequencing of gyrA and gyrB genes (N = 120) helped to identify point mutations in 60 isolates (30 from antrum and 30 from esophagus) of five dyspeptic patients. Double (Asn87Thr and Asp91Asn) and single (Asn87Ile or Asn87Thr) mutations in the gyrA gene were identified in the esophageal mucosa. These mutations have been commonly found in the stomach. Occurrence of a single (Asn87Ile) mutation was associated with high resistance (minimum inhibitory concentration ≥ 32 μg/mL) to LVX. Only a single (Ser479Gly) mutation was found in the gyrB gene in both mucosae. One patient presented isolates with no mutations in the two genes studied. Isolates with the same mutation pattern in individual hosts revealed identical genetic profiles for these genes, confirming that isolates identified in the esophageal mucosa come from isolates colonizing the stomach. Helicobacter pylori resistance to LVX in the esophagus is related to double- and single-point mutations in gyrA and gyrB genes, such as those found in the stomach. Levofloxacin should be applied with caution, because its antibiotic effect on H. pylori is decreasing in Latin America, perhaps owing to high prescription rates.

Helicobacter pylori induces caudal-type homeobox protein 2 and cyclooxygenase 2 expression by modulating microRNAs in esophageal epithelial cells

Dysregulation of microRNAs (miRNAs) has been linked to virulence factors of Helicobacter pylori. The role of H. pylori in esophageal disease has not been clearly defined. We previously reported that H. pylori esophageal colonization promotes the incidence of Barrett's esophagus and esophageal adenocarcinoma in vivo. Here, we studied the direct effects of H. pylori on the transformation of esophageal epithelial cells, with particular focus on whether H. pylori exerts its effects by modulating miRNAs and their downstream target genes. The normal human esophageal cell line HET‐1A was chronically exposed to H. pylori extract and/or acidified deoxycholic acid for up to 36 weeks. The miRNA profiles of the esophageal epithelial cells associated with H. pylori infection were determined by microarray analysis. We found that chronic H. pylori exposure promoted acidified deoxycholic acid‐induced morphological changes in HET‐1A cells, along with aberrant overexpression of intestinal metaplasia markers and tumorigenic factors, including caudal‐type homeobox protein 2 (CDX2), mucin 2, and cyclooxygenase 2 (COX2). Helicobacter pylori modified the miRNA profiles of esophageal epithelial cells, particularly aberrant silencing of miR‐212‐3p and miR‐361‐3p. Moreover, in biopsies from Barrett's esophagus patients, esophageal H. pylori colonization was associated with a significant decrease in miR‐212‐3p and miR‐361‐3p expression. Furthermore, we identified COX2 as a target of miR‐212‐3p, and CDX2 as a target of miR‐361‐3p. Helicobacter pylori infection of esophageal epithelial cells was associated with miRNA‐mediated upregulation of oncoprotein CDX2 and COX2. Our observations provide new evidence about the molecular mechanisms underlying the association between H. pylori infection and esophageal carcinogenesis.

Phylogeographic diversity and mosaicism of the Helicobacter pylori tfs integrative and conjugative elements

Background

The genome of the gastric pathogen Helicobacter pylori is characterised by considerable variation of both gene sequence and content, much of which is contained within three large genomic islands comprising the cag pathogenicity island (cagPAI) and two mobile integrative and conjugative elements (ICEs) termed tfs3 and tfs4. All three islands are implicated as virulence factors, although whereas the cagPAI is well characterised, understanding of how the tfs elements influence H. pylori interactions with different human hosts is significantly confounded by limited definition of their distribution, diversity and structural representation in the global H. pylori population.

Results

To gain a global perspective of tfs ICE population dynamics we established a bioinformatics workflow to extract and precisely define the full tfs pan-gene content contained within a global collection of 221 draft and complete H. pylori genome sequences. Complete (ca. 35-55kbp) and remnant tfs ICE clusters were reconstructed from a dataset comprising > 12,000 genes, from which orthologous gene complements and distinct alleles descriptive of different tfs ICE types were defined and classified in comparative analyses. The genetic variation within defined ICE modular segments was subsequently used to provide a complete description of tfs ICE diversity and a comprehensive assessment of their phylogeographic context. Our further examination of the apparent ICE modular types identified an ancient and complex history of ICE residence, mobility and interaction within particular H. pylori phylogeographic lineages and further, provided evidence of both contemporary inter-lineage and inter-species ICE transfer and displacement.

Conclusions

Our collective results establish a clear view of tfs ICE diversity and phylogeographic representation in the global H. pylori population, and provide a robust contextual framework for elucidating the functional role of the tfs ICEs particularly as it relates to the risk of gastric disease associated with different tfs ICE genotypes.

Electronic supplementary material

The online version of this article (10.1186/s13100-018-0109-4) contains supplementary material, which is available to authorized users.

Regulatory Effects of Black Rice Extract on Helicobacter pylori Infection-Induced Apoptosis

SCOPE

Black rice extract (BRE) contains cyanidin 3-O-glucoside (C3G), an anthocyanin, as the major component. In this study, we found that BRE inhibits the mRNA and protein expression of genes encoding cytotoxin-associated protein A (cagA) and vacuolating protein A (vacA) in Helicobacter pylori 60190 strain.

METHODS AND RESULTS

We performed RT-PCR and western blotting to show that BRE inhibits the mRNA and protein expression of SecA. Because SecA is involved in VacA export in bacteria, our result suggests a positive correlation between BRE-induced inhibition of secA expression and VacA secretion. Further, we perform MTT assay and flow cytometry to show that BRE decreases the apoptosis of H. pylori-infected KATO III cells. Finally, we perform western blotting to show that the cell-protective effect of BRE is associated with decreased levels of active proapoptotic proteins caspases and PARP and increased levels of antiapoptotic proteins survivin and XIAP in H. pylori-infected cells.

CONCLUSION

Thus, our results indicate that BRE acts as a potent inhibitor of the biogenesis of H. pylori virulence proteins and decreases the apoptosis of H. pylori-infected cells. Moreover, our results suggest that BRE can be used to exert beneficial effects in patients with gastroduodenal diseases caused by H. pylori.

Colonization, localization, and inflammation: the roles of H. pylori chemotaxis in vivo

Helicobacter pylori is a Gram-negative bacterium that infects half of the world's population, causing gastritis, peptic ulcers, and gastric cancer. To establish chronic stomach infection, H. pylori utilizes chemotaxis, driven by a conserved signal transduction system. Chemotaxis allows H. pylori to sense an array of environmental and bacterial signals within the stomach, guiding its motility towards its preferred niche within the gastric mucosa and glands. Fine-tuned localization, regulated by the chemotaxis system, enables robust colonization during the acute stage of infection. During chronic infection, chemotaxis helps maintain bacterial populations and modulates the host immune response. Given its importance in host colonization and disease, chemotaxis is an attractive target for future treatments against H. pylori infections.

Focus on periodontal disease and colorectal carcinoma

Diagnosis of focal disease, the theory that the human oral microbial (HOM) could affect the onset and development of systemic diseases, was very popular in the past, but the lack of scientific evidence has led to the abandonment of this idea. Interestingly, increasing evidence over the past 3 or so decades suggests that HOM can indeed serve as a reservoir for systemic dissemination of pathogenic bacteria and their toxins in distant body sites, favouring the developments of malignant tumours. Malignant tumours are complex communities of oncogenically transformed cells with aberrant genomes, associated non-neoplastic cells including immune and stromal cells, and sometimes HOM, including bacteria and viruses. Recent data suggest that HOM and periodontal disease play an active role in the pathogenesis of colorectal cancer, in fact HOM has been found within the colorectal cancer microenvironment, and the composition of the HOM was different from that of adjacent non-neoplastic tissue. An association of fusobacterium nucleatum with the colonic mucosa of colorectal cancer has been proven. Several questions thus arise. Is periodontal disease a risk factor for colorectal carcinoma? Given the connectivity of the digestive tract, could fusubacterium nucleatum or other HOM be involved in additional gastrointestinal disorders? Furthermore, based on the "mobility" of Fusubacterium nucleatum and the omnipresence of cadherins, could this organism be involved in cancers beyond the gastrointestinal tract? Answers to these questions will shed new lights on the role of the HOM in onset of diseases.

Changing trends in the prevalence of H. pylori infection in Japan (1908-2003): a systematic review and meta-regression analysis of 170,752 individuals

Changing trends in the prevalence of H. pylori infection in the general population over time are thought to be the main driving force behind the declining gastric cancer mortality in Japan. However, whether the prevalence of H. pylori infection itself shows a birth-cohort pattern needs to be corroborated. We performed a systematic review of studies that reported the prevalence of H. pylori infection among Japanese individuals. Meta-regression was conducted in the framework of a generalized additive mixed model (GAMM) to account for heterogeneity in the prevalence of H. pylori infection as a function of birth year. The prevalence of H. pylori infection confirmed a clear birth cohort pattern: the predicted prevalence (%, 95% CI) was 60.9 (56.3–65.4), 65.9 (63.9–67.9), 67.4 (66.0–68.7), 64.1 (63.1–65.1), 59.1 (58.2–60.0), 49.1 (49.0–49.2), 34.9 (34.0–35.8), 24.6 (23.5–25.8), 15.6 (14.0–17.3), and 6.6 (4.8–8.9) among those who were born in the year 1910, 1920, 1930, 1940, 1950, 1960, 1970, 1980, 1990, and 2000, respectively. The present study demonstrated a clear birth-cohort pattern of H. pylori infection in the Japanese population. The decreased prevalence of H. pylori infection in successive generations should be weighed in future gastric cancer control programs.

Association of anaemia with Helicobacter pylori infection: a retrospective study

The role of Helicobacter pylori (H. pylori) infection in haematological system diseases is not well understood. We conducted this retrospective study to explore the association between H. pylori infection and anaemia in the Chinese population. This retrospective study was performed in Aerospace Center Hospital in Beijing. We derived the data from the registration system of the physical population between 2012-2016. Logistic regression models were used to explore the association between H. pylori infection and anaemia. Among 17,791 subjects, there were 7,804 (43.9%) subjects with H. pylori infection and 950 (5.3%) with anaemia. The prevalence of anaemia in the H. pylori (+) group was significantly higher than in the H. pylori (-) group after adjusting for age, sex, marriage, underlying diseases and body mass index. Compared to H. pylori (-), the OR of H. pylori (+) was 1.39 for moderate-to-severe anaemia and 1.05 for mild anaemia. The level of haemoglobin was lower in the H. pylori (+) group than in the H. pylori (-) group. This study indicates that H. pylori infection may be related to anaemia and haemoglobin level in the Chinese population.

Gastric TFF1 Expression from Acute to Chronic Helicobacter Infection

TFF1, a mucin-associated secreted peptide of gastric mucous cells, is known as a protective agent for stomach epithelium under different stimuli, but its role upon Helicobacter infection is still not clear. In this paper we characterized TFFs expression, with particular attention to TFF1, under Helicobacter infection in gastric cell lines. A mouse model was used to distinguish TFF1 mRNA expression between acute and chronic stages of Helicobacter infection. Our results show that TFF1 expression is induced in infected cells; in addition, the inflammatory response upon Helicobacter infection is inversely associated to pre-existing TFF1 protein levels. In infected mice, TFF1 is initially upregulated in gastric antrum in the acute phase of infection, along with IL-1β and IL-6. Then, expression of TFF1 is gradually silenced when the infection becomes chronic and IFN-γ, CXCL5, and CXCL15 reach higher levels. Our data suggest that TFF1 might help cells to counteract bacteria colonization and the development of a chronic inflammation.

Antibody reactivity against Helicobacter pylori proteins in a sample of the Spanish adult population in 2008-2013

BACKGROUND

Differences in Helicobacter pylori protein expression have been related to the risk of severe gastric diseases. In Spain, a marked geographic pattern in gastric cancer mortality has long been reported.

OBJECTIVE

To characterize antibody reactivity patterns against 16 H. pylori proteins, by age, sex, and region of birth, in a large sample of the Spanish adult population.

MATERIALS AND METHODS

Antibody reactivity was quantified by H. pylori multiplex serology in a sample from the control group of the multicase-control study MCC-Spain. For this analysis, 2555 population-based controls were included. Each participant was classified as seropositive or seronegative for each protein according to specific cutoffs. Overall H. pylori seroprevalence was defined as positivity against ≥4 proteins. Descriptive analyses by age, sex, and region of birth were performed for both seroprevalence and seroreactivity (continuous measure). Differences among groups were tested by logistic and linear regression models.

RESULTS

Overall H. pylori seroprevalence increased with age in both sexes. For ages 55-74, seroprevalence was lower in women than in men (84% vs 92%, P<.001). Region of birth explained 7% of the variability in seroprevalence. Among H. pylori seropositive subjects, proteins with the highest seroprevalence were GroEL, NapA, HP231, and Omp. Seropositivity for most of the proteins increased or remained stable with age, rising mainly for CagA, GroEL, and HyuA in women. A clear cohort effect was not observed.

CONCLUSIONS

This is the first study to describe the antibody patterns against 16 H. pylori proteins in the Spanish population. We found variability in the H. pylori antibody profiles according to both individual factors such as age and sex, and environmental factors such as the region of birth. The slightness of the reduction in seropositivity with decreasing age highlights the ongoing importance of this infection.

Upfront immunohistochemistry improves specificity of Helicobacter pylori diagnosis. A French pathology laboratory point of view

BACKGROUND

There is no consensus about the histopathologic methods to detect Helicobacter pylori in gastric biopsies to date. We aimed to question about the value of upfront anti-H. pylori immunohistochemistry in this field.

MATERIAL AND METHODS

We led a retrospective study about the rate of H. pylori-positive gastric biopsies before and after the implementation of upfront immunohistochemistry, the inter-rater and intermethods agreements in H. pylori identification about Hematoxylin-Eosin Saffron (HES), Giemsa, and immunohistochemistry stains and the histopathologic features associated with low amounts of H. pylori.

RESULTS

First, the rate of H. pylori-positive gastric biopsies significantly diminished after the implementation of upfront immunohistochemistry (from 21.15% to 12.56%, P<.0001), suggesting potential overdiagnosis of H. pylori infection before the use of immunohistochemistry. Secondly, immunohistochemistry was the most reproducible and performing stain (kappa values >0.80), but HES and Giemsa stains also presented good-to-very good agreements. Finally, less than 1% of gastric biopsies with inconspicuous H. pylori infection showed no mucosal injury pointing out that any HES-detected mucosal injury could help to preselect the gastric biopsies requiring ancillary stains for the detection of H. pylori.

CONCLUSIONS

Albeit being considered as a gold standard in the detection of H. pylori, the interest of using immunohistochemistry as an upfront stain on gastric biopsies is still debated. In our opinion, its use in second line in case of ambiguous HE/HES-Giemsa result is more appropriate. Further effort is needed to optimize the inexpensive but feasible HE/HES-based detection of H. pylori.

Mechanistic insights into type I toxin antitoxin systems in Helicobacter pylori: the importance of mRNA folding in controlling toxin expression

Type I toxin-antitoxin (TA) systems have been identified in a wide range of bacterial genomes. Here, we report the characterization of a new type I TA system present on the chromosome of the major human gastric pathogen, Helicobacter pylori. We show that the aapA1 gene encodes a 30 amino acid peptide whose artificial expression in H. pylori induces cell death. The synthesis of this toxin is prevented by the transcription of an antitoxin RNA, named IsoA1, expressed on the opposite strand of the toxin gene. We further reveal additional layers of post-transcriptional regulation that control toxin expression: (i) transcription of the aapA1 gene generates a full-length transcript whose folding impedes translation (ii) a 3΄ end processing of this message generates a shorter transcript that, after a structural rearrangement, becomes translatable (iii) but this rearrangement also leads to the formation of two stem-loop structures allowing formation of an extended duplex with IsoA1 via kissing-loop interactions. This interaction ensures both the translation inhibition of the AapA1 active message and its rapid degradation by RNase III, thus preventing toxin synthesis under normal growth conditions. Finally, a search for homologous mRNA structures identifies similar TA systems in a large number of Helicobacter and Campylobacter genomes.