Pathogenesis and clinical management of Helicobacter pylori gastric infection

The role of toll-like receptors in peptic ulcer disease

Helicobacter pylori (HP) is the primary etiologic factor that induces events in the immune system that lead to peptic ulcers. Toll-like receptors (TLRs) are an important part of the innate immune system, as they play pivotal roles in pathogen-associated molecular pattern (PAMP) recognition of HP as well host-associated damage-associated molecular patterns (DAMPs). Recent advancements such as COX-2 production, LPS recognition through TLR2, CagL, and CagY protein of HP activating TLR5, TLR9 activation via type IV secretion system (T4SS) using DNA transfer, TLR polymorphisms, their adaptor molecules, cytokines, and other factors play a significant role in PUD. Thus, some novel PUD treatments including Chuyou Yuyang granules, function by TLR4/NF-κB signaling pathway suppression and TNF-α and IL-18 inhibition also rely on TLR signaling. Similarly glycyrrhetinic acid (GA) treatment activates TLR-4 in Ana-1 cells not via TRIF, but via MYD88 expression, which is significantly upregulated to cure PUD. Therefore, understanding TLR signaling complexity and its resultant immune modulation after host-pathogen interactions is pivotal to drug and vaccine development for other diseases as well including cancer and recent pandemic COVID-19. In this review, we summarize the TLRs and HP interaction; its pathophysiology-related signaling pathways, polymorphisms, and pharmaceutical approaches toward PUD.

Helicobacter pylori in gastric cancer: Features of infection and their correlations with long-term results of treatment

BACKGROUND

Helicobacter pylori (H. pylori) is a spiral-shaped bacterium responsible for the development of chronic gastritis, gastric ulcer, gastric cancer (GC), and MALT-lymphoma of the stomach. H. pylori can be present in the gastric mucosa (GM) in both spiral and coccoid forms. However, it is not known whether the severity of GM contamination by various vegetative forms of H. pylori is associated with clinical and morphological characteristics and long-term results of GC treatment.

AIM

To establish the features of H. pylori infection in patients with GC and their correlations with clinical and morphological characteristics of diseases and long-term results of treatment.

METHODS

Of 109 patients with GC were included in a prospective cohort study. H. pylori in the GM and tumor was determined by rapid urease test and by immunohistochemically using the antibody to H. pylori. The results obtained were compared with the clinical and morphological characteristics and prognosis of GC. Statistical analysis was performed using the Statistica 10.0 software.

RESULTS

H. pylori was detected in the adjacent to the tumor GM in 84.5% of cases, of which a high degree of contamination was noted in 50.4% of the samples. Coccoid forms of H. pylori were detected in 93.4% of infected patients, and only coccoid-in 68.9%. It was found that a high degree of GM contamination by the coccoid forms of H. pylori was observed significantly more often in diffuse type of GC (P = 0.024), in poorly differentiated GC (P = 0.011), in stage T3-4 (P = 0.04) and in N1 (P = 0.011). In cases of moderate and marked concentrations of H. pylori in GM, a decrease in 10-year relapse free and overall survival from 55.6% to 26.3% was observed (P = 0.02 and P = 0.07, respectively). The relationship between the severity of the GM contamination by the spiral-shaped forms of H. pylori and the clinical and morphological characteristics and prognosis of GC was not revealed.

CONCLUSION

The data obtained indicates that H. pylori may be associated not only with induction but also with the progression of GC.

Helicobacter pylori Infection in Geriatric Patients: Current Situation and Treatment Regimens

Helicobacter pylori (H. pylori) has so far infected more than half the global population. It is the most important and controllable risk factor for gastric cancer. The elderly, who are at a higher incidence of the infection, are also commonly found to develop antibiotic resistance. The symptoms, diagnosis, clinical features (of gastric or extra-digestive diseases), and treatment of H. pylori infection in the elderly, are different from that in the non-elderly. Health conditions, including comorbidities and combined medication have limited the use of regular therapies in elderly patients. However, they can still benefit from eradication therapy, thus preventing gastric mucosal lesions and gastric cancer. In addition, new approaches, such as dual therapy and complementary therapy, have the potential to treat older patients with H. pylori infection.

Selective Targeting of Human and Animal Pathogens of the Helicobacter Genus by Flavodoxin Inhibitors: Efficacy, Synergy, Resistance and Mechanistic Studies

Antimicrobial resistant (AMR) bacteria constitute a global health concern. Helicobacter pylori is a Gram-negative bacterium that infects about half of the human population and is a major cause of peptic ulcer disease and gastric cancer. Increasing resistance to triple and quadruple H. pylori eradication therapies poses great challenges and urges the development of novel, ideally narrow spectrum, antimicrobials targeting H. pylori. Here, we describe the antimicrobial spectrum of a family of nitrobenzoxadiazol-based antimicrobials initially discovered as inhibitors of flavodoxin: an essential H. pylori protein. Two groups of inhibitors are described. One group is formed by narrow-spectrum compounds, highly specific for H. pylori, but ineffective against enterohepatic Helicobacter species and other Gram-negative or Gram-positive bacteria. The second group includes extended-spectrum antimicrobials additionally targeting Gram-positive bacteria, the Gram-negative Campylobacter jejuni, and most Helicobacter species, but not affecting other Gram-negative pathogens. To identify the binding site of the inhibitors in the flavodoxin structure, several H. pylori-flavodoxin variants have been engineered and tested using isothermal titration calorimetry. An initial study of the inhibitors capacity to generate resistances and of their synergism with antimicrobials commonly used in H. pylori eradication therapies is described. The narrow-spectrum inhibitors, which are expected to affect the microbiota less dramatically than current antimicrobial drugs, offer an opportunity to develop new and specific H. pylori eradication combinations to deal with AMR in H. pylori. On the other hand, the extended-spectrum inhibitors constitute a new family of promising antimicrobials, with a potential use against AMR Gram-positive bacterial pathogens.

Effect of Anti-Hp treatment on nutritional status of children with Helicobacter Pylori-Positive Gastritis and its clinical significance

Objectives

To evaluate the outcome of anti-HP treatment on the nutritional status of children with Helicobacter pylori-positive gastritis.

Methods

Sixty children with Helicobacter pylori-positive gastritis admitted to our hospital from June 2018 to June 2020 were selected as the experimental group, and 60 healthy normal people (Hp negative) were selected as the control group. The experimental group were given anti-HP treatment, and the improvement of their clinical symptoms after treatment and the changes of nutritional indexes such as hemoglobin and serum ferritin were observed one year after treatment. Gastroscopy was performed before treatment and four weeks after treatment, and the improvement of gastric inflammation and the positive rate of Hp were compared and analyzed before and after treatment.

Results

The nutritional indicators of the children in experimental group were inferior compared with those in the control group (p<0.05). The clinical symptoms and signs of the experimental group were significantly alleviated after anti-Hp treatment, and the biochemical indicators were significantly improved after one Year of follow-up compared with those before treatment (p<0.05). The incidence of moderate and severe gastric mucosal inflammation in the experimental group decreased from 70% before treatment to 17% (p<0.05). The HP infection decreased from 100% before treatment to 13% (p<0.05).

Conclusion

Helicobacter pylori infection has a negative impact on the nutritional status of children. Anti-HP therapy can improve the gastrointestinal symptoms and nutritional status of children, which plays an important role in the growth and development of children.

Efficacy of Loop-Mediated Isothermal Amplification for H. pylori Detection as Point-of-Care Testing by Noninvasive Sampling

For targeted eradication of Helicobacterpylori (H. pylori) to reduce gastric cancer burden, a convenient approach is definitely needed. The purpose of this study was to evaluate the LAMP assay for H. pylori detection using samples collected by noninvasive and self-sampling methods. The available LAMP assay for H. pylori detection was appraised and verified using reference and clinically isolated H. pylori strains. In addition, a clinical study was conducted to assess the LAMP assay on 51 patients, from whom saliva, oral brushing samples, feces, corpus, and antrum specimens were available. Clarithromycin resistance was also analysed through detection of A2143G mutation using the LAMP-RFLP method. The validation and verification analysis demonstrated that the LAMP assay had an acceptable result in terms of specificity, sensitivity, reproducibility, and accuracy for clinical settings. The LAMP assay showed a detection limit for H. pylori down to 0.25 fg/µL of genomic DNA. An acceptable consensus was observed using saliva samples (sensitivity 58.1%, specificity 84.2%, PPV 85.7%, NPV 55.2%, accuracy 68%) in comparison to biopsy sampling as the gold standard. The performance testing of different combinations of noninvasive sampling methods demonstrated that a combination of saliva and oral brushing could achieve a sensitivity of 74.2% and a specificity of 57.9%. A2143G mutation detection by LAMP-RFLP showed perfect consensus with Sanger sequencing results. It appears that the LAMP assay in combination with noninvasive and self-sampling as a point-of-care testing (POCT) approach has potential usefulness to detect H.pylori infection in clinic settings and screening programs.

Colostrum IgA1 antibodies recognize antigens from Helicobacter pylori and prevent cytoskeletal changes in human epithelial cells

Helicobacter pylori is a gram-negative bacterium found on the luminal surface of the gastric mucosa in at least 50% of the world's human population. The protective effect of breastfeeding against H. pylori infection has been extensively reported; however, the mechanisms behind this protection remain poorly understood. Human IgA from colostrum has reactivity against H. pylori antigens. Despite that IgA1 and IgA2 display structural and functional differences, their reactivity against H. pylori had not been previously determined. We attested titers and reactivity of human colostrum-IgA subclasses by ELISA, immunoblot, and flow cytometry. Colostrum samples from healthy mothers had higher titers of IgA; and IgA1 mostly recognized H. pylori antigens. Moreover, we found a correlation between IgA1 reactivity and their neutralizing effect determined by inhibition of cytoskeletal changes in AGS cells infected with H. pylori. In conclusion, colostrum-IgA reduces H. pylori infection of epithelial gastric cells, suggesting an important role in preventing the bacteria establishment during the first months of life. As a whole, these results suggest that IgA1 from human colostrum provides protection that may help in the development of the mucosal immune system of newborn children. This article is protected by copyright. All rights reserved.

Helicobacter urease suppresses cytotoxic CD8 + T cell responses through activating Myh9-dependent induction of PD-L1

As a key virulence factor for persistent colonization, Urease B subunit (UreB) is considered to be an ideal vaccine antigen against Helicobacter pylori (H. pylori) infection. However, the role and molecular mechanisms of UreB involved in immune microenvironment dysregulation still remains largely unknown. In the present study, we evaluated the effects of UreB on macrophage activation and found that UreB induced PD-L1 accumulation on Bone marrow-derived macrophages (BMDMs). Co-culture assays further revealed that UreB-induced PD-L1 expression on BMDMs significantly decreased the proliferation and secretion of cytolytic molecules (granzyme B and perforin) of splenic CD8 + T cells isolated from inactivated H. pylori-immunized mice. More importantly, myosin heavy chain 9 (Myh9) was confirmed to be a direct membrane receptor of UreB via using LC-MS/MS and Co-immunoprecipitation and required for PD-L1 upregulation on BMDMs. Molecular studies further demonstrated that the interaction between UreB and Myh9 decreased GCN2 autophosphorylation and enhanced intracellular pool of amino acids, leading to the upregulation of S6K phosphorylation, a commonly used marker for monitoring activation of mTORC1 signaling activity. Furthermore, blocking mTORC1 activation with its inhibitor Temsirolimus reversed UreB-induced PD-L1 upregulation and the subsequently inhibitory effects of BMDMs on activation of cytotoxic CD8 + T cell responses. Overall, our data unveil a novel immunosuppressive mechanism of UreB during H. pylori infection, which may provide valuable clue for the optimization of H. pylori vaccine.

Comparative serum microRNA array analysis of the spleen-stomach dampness-heat syndrome in different diseases: Chronic hepatitis B and chronic gastritis

Spleen-stomach dampness-heat syndrome (SSDHS) is the common Traditional Chinese Medicine (TCM) syndrome observed in both chronic hepatitis B (CHB) and chronic gastritis (CG). The specialized TCM prescription for CHB and CG patients with SSDHS is same, but there is limited information about the biological characteristics of this TCM syndrome. This study aimed to identify the serum miRNAs profile for the SSDHS in two different diseases in order to evaluate the miRNA-mediated biological characteristics of this TCM syndrome. We performed comparative microarray analysis of serum miRNA expression profiles in 10 CHB patients with SSDHS (SSDHS-CHB), 10 CG patients with SSDHS (SSDHS-CG), and 10 healthy controls (HC). The selected miRNAs were further validated by qRT-PCR in 13 SSDHS-CHB patients, 13 SSDHS-CG patients, and 13 HC. Moreover, bioinformatics analysis (GO and KEGG pathway enrichment analyses) was applied to identify the involved target genes and pathways for these selected miRNAs. Nine significantly differentially expressed (SDE)-miRNAs in the SSDHS-CHB group and 24 SDE-miRNAs in the SSDHS-CG group were identified, compared with the HC group (fold change >2.0 and p < .05). Among these, upregulated hsa-miR-483-3p and downregulated hsa-miR-223-3p were identified as the common SDE-miRNAs for both SSDHS-CHB and SSDHS-CG groups. Bioinformatics analysis of the common SDE-miRNA's target genes showed their involvement in the regulation of inflammation, immune response, and tumorigenesis. SSDHS-specific hsa-miR-483-3p and hsa-miR-223-3p identified in this study indicated a relevance to the underlying biological basis of SSDHS, and may provide scientific basis for the application of same TCM prescription in CHB and CG.

Different dose of new generation proton pump inhibitors for the treatment of Helicobacter pylori infection: A meta-analysis

The evidence on whether high-dose new generation proton pump inhibitors (PPIs) including rabeprazole and esomeprazole achieve a higher eradication rate of Helicobacter pylori has not been assessed. The primary comparison was eradication and adverse events (AEs) rate of standard (esomeprazole 20 mg bid, rabeprazole 10 mg bid) versus high-dose (esomeprazole 40 mg bid, rabeprazole 20 mg bid) PPIs. Sub-analyses were performed to evaluate the eradication rate between Asians and Caucasians, clarithromycin-resistance (CAM-R) strains, and clarithromycin-sensitivity (CAM-S) strains of different dose PPIs. We conducted a literature search for randomized controlled trials comparing high-with standard-dose esomeprazole and rabeprazole for H. pylori eradication and AEs. A total of 12 trials with 2237 patients were included. The eradication rate of high-dose PPIs was not significantly superior to standard-dose PPIs regimens: 85.3% versus 84.2%, OR 1.09 (0.86–1.37), P = 0.47. The high dose induced more AEs than those of the standard dose, but didn’t reach statistical significance (OR 1.25, 95% CI: 0.99–1.56, P = 0.06). Subgroup analysis showed that the difference in eradication rate of PPIs between high- and standard-dose groups were not statistically significant both in Asians (OR 0.99, 95% CI 0.75–1.32, P = 0.97) and Caucasians (OR 1.27, 95% CI 0.84–1.92, P = 0.26). Furthermore, there were similar eradication rates in CAM-S (OR 1.2; 95% CI 0.58–2.5; P = 0.63) and CAM-R strains (OR 1.08; 95% CI 0.45–2.56; P = 0.87) between the standard-and high-dose groups. High and standard dosages of new generation of the PPIs showed similar H. pylori eradication rates and AEs as well as between Asian versus Caucasian populations, with or without clarithromycin-resistance. However, further studies are needed to confirm.

Impact of Dietary Patterns on H. pylori Infection and the Modulation of Microbiota to Counteract Its Effect. A Narrative Review

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonizes the stomach and can induce gastric disease and intra-gastric lesions, including chronic gastritis, peptic ulcers, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. This bacterium is responsible for long-term complications of gastric disease. The conjunction of host genetics, immune response, bacterial virulence expression, diet, micronutrient availability, and microbiome structure influence the disease outcomes related to chronic H. pylori infection. In this regard, the consumption of unhealthy and unbalanced diets can induce microbial dysbiosis, which infection with H. pylori may contribute to. However, to date, clinical trials have reported controversial results and current knowledge in this field is inconclusive. Here, we review preclinical studies concerning the changes produced in the microbiota that may be related to H. pylori infection, as well as the involvement of diet. We summarize and discuss the last approaches based on the modulation of the microbiota to improve the negative impact of H. pylori infection and their potential translation from bench to bedside.

Bacterial Infection and Non-Hodgkin B-Cell Lymphoma: Interactions between Pathogen, Host and the Tumor Environment

Non-Hodgkin B-cell lymphomas (NHL) are a heterogeneous group of lymphoid neoplasms with complex etiopathology, rich symptomatology, and a variety of clinical courses, therefore requiring different therapeutic approaches. The hypothesis that an infectious agent may initiate chronic inflammation and facilitate B lymphocyte transformation and lymphogenesis has been raised in recent years. Viruses, like EBV, HTLV-1, HIV, HCV and parasites, like Plasmodium falciparum, have been linked to the development of lymphomas. The association of chronic Helicobacter pylori (H. pylori) infection with mucosa-associated lymphoid tissue (MALT) lymphoma, Borrelia burgdorferi with cutaneous MALT lymphoma and Chlamydophila psittaci with ocular adnexal MALT lymphoma is well documented. Recent studies have indicated that other infectious agents may also be relevant in B-cell lymphogenesis such as Coxiella burnettii, Campylobacter jejuni, Achromobacter xylosoxidans, and Escherichia coli. The aim of the present review is to provide a summary of the current literature on infectious bacterial agents associated with B-cell NHL and to discuss its role in lymphogenesis, taking into account the interaction between infectious agents, host factors, and the tumor environment.

Vaccine development against Helicobacter pylori: from ideal antigens to the current landscape

Introduction: The interest of the world scientific community for an effective vaccine against Helicobacter pylori infection arises from its high prevalence and association with many diseases. Moreover, with an immunological response that is not always effective for the eradication of the bacteria and an increasing antibiotic resistance in the treatment of this infection, the search for a vaccine and new therapeutic modalities to control this infection is urgent.Areas covered: We bring an overview of the infection worldwide, discussing its prevalence, increasing resistance to antibiotics used in its therapy, in addition to the response of the immune system to the infection registered so far. Moreover, we address the most used antigens and their respective immunological responses expected or registered up to now. Finally, we address the trials and their partial results in development for such vaccines.Expert opinion: Although several studies for the development of an effective vaccine against this pathogen are taking place, many are still in the preclinical phase or even without updated information. In this sense, taking into account the high prevalence and association with important comorbidities, the interest of the pharmaceutical industry in developing an effective vaccine against this pathogen is questioned.

A review on the structures and biological activities of anti-Helicobacter pylori agents

Helicobacter pylori is one of the main causal risk factor in the generation of chronic gastritis, gastroduodenal ulcers and gastric carcinoma. Thus, the eradication of H. pylori infection is an important way for preventing and managing the gastric diseases. Multiple-therapy with several antibacterial agents is used for the eradication of H. pylori infections; however the increase of resistance to H. pylori strains has resulted in unsatisfactory eradication and unsuccessful treatment. Furthermore, the combination therapy with high dosing leads to the disruption of intestinal microbial flora and undesired side effects. Therefore, the search for new therapeutic agents with high selectivity against H. pylori is a field of current interest. In recent years, diverse compounds originating from natural sources or synthetic drug design programs were evaluated and tried to optimize for applying against H. pylori. In this review, we have described various classes of anti-H. pylori compounds, their structure-activity relationship studies, and mechanism of actions, which could be useful for the development of new drugs for the treatment of H. pylori infections.

N-Acetylcysteine (NAC): Impacts on Human Health

N-acetylcysteine (NAC) is a medicine widely used to treat paracetamol overdose and as a mucolytic compound. It has a well-established safety profile, and its toxicity is uncommon and dependent on the route of administration and high dosages. Its remarkable antioxidant and anti-inflammatory capacity is the biochemical basis used to treat several diseases related to oxidative stress and inflammation. The primary role of NAC as an antioxidant stems from its ability to increase the intracellular concentration of glutathione (GSH), which is the most crucial biothiol responsible for cellular redox imbalance. As an anti-inflammatory compound, NAC can reduce levels of tumor necrosis factor-alpha (TNF-α) and interleukins (IL-6 and IL-1β) by suppressing the activity of nuclear factor kappa B (NF-κB). Despite NAC's relevant therapeutic potential, in several experimental studies, its effectiveness in clinical trials, addressing different pathological conditions, is still limited. Thus, the purpose of this chapter is to provide an overview of the medicinal effects and applications of NAC to human health based on current therapeutic evidence.

Helicobacter pylori-induced protein tyrosine phosphatase receptor type C as a prognostic biomarker for gastric cancer

Background

Helicobacter pylori (H. pylori) infection is closely associated with the tumorigenesis of gastric cancer. The aim of the present study was to identify the key regulator in H. pylori-related gastric cancer and to study the expression level and clinical value of the indicated key regulator in gastric cancer.

Methods

The GSE6143 dataset was used to identify differentially expressed genes (DEGs) with limma R package, and enrichment analysis was done using the Metascape web-based portal. The protein-protein interaction analysis was done using Search Tool for the Retrieval of Interacting Genes/Proteins. Gastric adenocarcinoma AGS and BGC-823 cells were treated with H. pylori strain 26695 to construct the in vitro H. pylori infection model, and quantitative reverse transcription polymerase chain reaction was used to analyze the mRNA levels of indicated genes. The correlation analysis between two genes in gastric cancer was done by GEPIA. Furthermore, the PTPRC expression by pathological features analysis was conducted in UALCAN, an easy to use, interactive web-portal (http://ualcan.path.uab.edu). The survival analysis for gastric cancer, based on PTPRC expression levels, was done using the Kaplan-Meier plotter.

Results

DEGs in gastric mucosa with or without H. pylori infection were identified and enriched in immune-related pathways and cancer pathways. The protein-protein interaction analysis confirmed the enrichment analysis of gene ontology. H. pylori strain 26695 exposure also confirmed the alteration of gene expression levels in AGS and BGC-823 cells. PTPRC was co-expressed with CSF2RB and TNFRSF7, indicating a significant positive correlation in gastric cancer. PTPRC was overexpressed in gastric cancer, and the overexpression of PTPRC was positively correlated with the progression of gastric cancer. Furthermore, the high expression of PTPRC could act as a poor prognostic factor for gastric cancer patients, especially for those at advanced stage.

Conclusions

H. pylori-induced PTPRC is overexpressed in gastric cancer, and the overexpression of PTPRC is positively associated with the development of gastric cancer. The high expression of PTPRC could serve as poor prognostic biomarker for gastric cancer patients, especially for those at advanced stage. H. pylori-induced PTPRC is a prognostic biomarker for gastric cancer.

Pharmacist-Managed Helicobacter pylori Treatment Service Within a Gastroenterology Clinic: Workflow and Real-World Experiences

BACKGROUND

Treatment eradication rates of Helicobacter pylori, a gastrointestinal infection, are 70% to 90% in clinical studies but lower in real-world settings. Potential barriers include multidrug regimen complexity or prescribing/administration errors. A pharmacist-managed H pylori treatment service was implemented to address these barriers and optimize treatment outcomes. The clinical pharmacist provided 2 services: (1) treatment education and monitoring for treatment-naïve patients and (2) treatment initiation, education, and monitoring for treatment-experienced patients.

OBJECTIVE

We aimed to evaluate the impact of a pharmacist-managed H pylori treatment service within a gastroenterology clinic.

METHODS

We conducted a retrospective observational cohort study of all patients referred to and seen in the pharmacist-managed H pylori treatment service from July 10, 2019, to December 31, 2020. Patient demographics, prior treatment history, course(s) of treatment prescribed, frequency of follow-ups, and outcomes posttreatment were collected.

RESULTS

The clinical pharmacist managed 60 referrals for 55 unique patients over a mean of 5 ± 2 visits. Five patients failed H pylori treatment and were re-referred. Identified barriers included prescribing/dispensing and administration errors. Posttreatment, 38 referrals tested for H pylori eradication, of which 100% of treatment-naïve patients and 69% of treatment-experienced patients were cured, and 13 (22%) referrals were lost to follow-up.

CONCLUSION AND RELEVANCE

This study described and assessed the impact of a pharmacist-managed H pylori treatment service in a gastroenterology clinic, in which various barriers were effectively addressed to optimize treatment outcomes. Future studies should focus on long-term outcome, impact on health care costs, and patient satisfaction with this service.

Design, expression, and purification of a multi-epitope vaccine against Helicobacter Pylori based on Melittin as an adjuvant

Helicobacter Pylori, a Gram-negative bacterium in the human stomach, causes adenocarcinoma and MALT (mucosa-associated lymphoid tissue) lymphoma in addition to infection and gastric ulcer. With regard to Helicobacter Pylori prevalence rate and widespread, producing an effective vaccine against this bacterium appears reasonable and necessary. Today, vaccine design by immunoinformatics is a promising solution in vaccine field. In the present study, potential immunodominant CD4⁺ T cell epitopes of UreB, HpaA, and NapA antigens were selected with a focus on IFN-γ secretion inducing ability. After joining the selected epitopes with KK and GPGPG linkers, sequence of Melittin, the major active protein of honey bee venom, was put in C-terminal by DPRVPSS linker as adjuvant. After reverse translation and codon optimization, the designed vaccine was cloned into pET-23a vector. The final construct was estimated as antigenic (71 & 74%) and non-allergenic with molecular weight of 36.785KD. The instability index (II) and codon frequency distribution were predicted to be 26.5 and 92%, respectively. The pET-23a vector transformed to the E.coli BL21 (DE3) strain. The evaluation of expression by SDS-PAGE analysis showed that the optimized expression is in SOB medium 8 h after induction by 0.5 mM IPTG. Finally, purification was performed by Ni-NTA affinity chromatography and Western blot analysis validated the purified protein. Future research is needed to investigate the designed vaccine efficiency against H. pylori, and also it's potential as a gastric cancer-preventive candidate.

Antimicrobial Resistance Gene Detection Methods for Bacteria in Animal-Based Foods: A Brief Review of Highlights and Advantages

Antimicrobial resistance is a major public health problem and is mainly due to the indiscriminate use of antimicrobials in human and veterinary medicine. The consumption of animal-based foods can contribute to the transfer of these genes between animal and human bacteria. Resistant and multi-resistant bacteria such as Salmonella spp. and Campylobacter spp. have been detected both in animal-based foods and in production environments such as farms, industries and slaughterhouses. This review aims to compile the techniques for detecting antimicrobial resistance using traditional and molecular methods, highlighting their advantages and disadvantages as well as the effectiveness and confidence of their results.

Highlighting the use of micro and nanoparticles based-drug delivery systems for the treatment of Helicobacter pylori infections

Due to the high adaptability of Helicobacter pylori and the low targeting specificity of the drugs normally used in pharmacological therapy, the strains are becoming increasingly resistant to these drugs, making it difficult to eradicate the infection. Thus, the search for new therapeutic approaches has been considered urgent. The incorporation of drugs in advanced drug delivery systems, such as nano and microparticles, would allow the improvement of the retention time in the stomach and the prolongation of drug release rates at the target site. Because of this, the present review article aims to highlight the use of micro and nanoparticles as important technological tools for the treatment of H. pylori infections, focussing on the main nanotechnological systems, including nanostructured lipid carriers, liposomes, nanoemulsion, metallic nanoparticles, and polymeric nanoparticles, as well as microtechnological systems such as gastroretentive dosage forms, among them mucoadhesive, magnetic and floating systems were highlighted.

Gastric histopathological features after the administration of omeprazole, amoxicillin, and clarithromycin in gastritis Helicobacter pylori rat model

OBJECTIVE

This research work aimed to assess the histopathological features and degree of gastritis severity in a rat model, induced by Helicobacter pylori infection after administering omeprazole, amoxicillin, and clarithromycin as the standard first-line eradication regimen.

MATERIAL AND METHODS

Twenty-one male rats were adapted for 7 days and randomly divided into three equal groups. Group 1 was considered a negative control. Group 2 and Group 3 were treated as H. pylori-inoculated groups. Group 2 was set as a positive control. Group 3 was administered omeprazole, amoxicillin, and clarithromycin as a first-line eradication regimen. Gastric histopathological examination was conducted. The difference in the severity of gastritis among the groups was examined using the one-way analysis of variance test. The significance was determined to be p < 0.05.

RESULTS

Gastritis was found in all inoculated groups. The severity of gastritis was highest in Group 2 (p < 0.05). We could see a refinement in gastritis severity after administering omeprazole, amoxicillin, and clarithromycin as a first-line eradication regimen (Group 3 vs. Group 2; p <0.05).

CONCLUSION

Gastritis, induced by the H. pylori rat model, was found in all inoculated groups. There was a refinement in the degree of gastritis severity after the administration of omeprazole, amoxicillin, and clarithromycin as a first-line eradication regimen.

Evaluation of Hematological Parameters of Helicobacter pylori-Infected Adult Patients at Southern Ethiopia: A Comparative Cross-Sectional Study

BACKGROUND

Helicobacter pylori (H. pylori) infection is a global public health problem, a higher burden of the infection was reported in developing countries including Ethiopia. It has been associated with several gastrointestinal diseases, and recently implicated in some hematological abnormalities. Despite the high prevalence of H. pylori infection in Ethiopia, there was limited data regarding the relationship between hematological parameters with H. pylori infection. Therefore, this study aimed to evaluate selected hematological parameters of H. pylori-infected patients attending Wachemo University Nigist Eleni Mohammed Memorial Referral Hospital (WUNEMMRH), Hosanna, Southern, Ethiopia.

METHODS AND MATERIALS

A comparative cross-sectional study was conducted from January to May 2019 among 374 (187 H. pylori-infected patients and 187controls) study participants. Data on socio-demographic characteristics were collected using a structured questionnaire. A five-milliliter venous blood sample was collected for hematological parameter analysis. Approximately two gram of stool specimen was collected to assess the presence of H. pylori antigen. Data were entered and analyzed by using SPSS version 21. Pearson correlation analysis and independent sample T-test was performed, and P-value < 0.05 was considered statistically significant.

RESULTS

Mean value of Hgb (p<0.001), RBC count (p<0.001), HCT (p<0.001), MCV (p=0.003), MCH (p=0.008), and MCHC (p=0.006) of H. pylori-infected patients were significantly lower than control group. However, the mean value of RDW (p=0.003) in H. pylori-infected patients was significantly higher than in the control group. About 13.3%, 7%, 6.4%, and 18.2% of H. pylori-infected patients showed reduced Hgb concentration, RBC count, HCT, and MCV values, respectively.

CONCLUSION

The study showed a statistically significant difference in the mean value of Hgb, RBC count, HCT, MCV, MCH, MCHC, and RDW of H. pylori-infected patients and controls. Thus, hematological parameters should be considered for proper diagnosis and management of H. pylori-infected patients and eradication of this microorganism from infected patients, determination of hematological parameters for H. pylori-infected patients were recommended.

Gut Microbiota: The Missing Link Between Helicobacter pylori Infection and Metabolic Disorders?

Helicobacter pylori (H. pylori) is a gram-negative bacterium that infects approximately 4.4 billion individuals worldwide. Although the majority of infected individuals remain asymptomatic, this bacterium colonizes the gastric mucosa causing the development of various clinical conditions as peptic ulcers, chronic gastritis and gastric adenocarcinomas and mucosa-associated lymphoid tissue lymphomas, but complications are not limited to gastric ones. Extradigestive pathologies, including metabolic disturbances such as diabetes, obesity and nonalcoholic fatty liver disease, have also been associated with H. pylori infection. However, the underlying mechanisms connecting H. pylori with extragastric metabolic diseases needs to be clarified. Notably, the latest studies on the topic have confirmed that H. pylori infection modulates gut microbiota in humans. Damage in the gut bacterial community (dysbiosis) has been widely related to metabolic dysregulation by affecting adiposity, host energy balance, carbohydrate metabolism, and hormonal modulation, among others. Taking into account that Type 2 diabetic patients are more prone to be H. pylori positive, gut microbiota emerges as putative key factor responsible for this interaction. In this regard, the therapy of choice for H. pylori eradication, based on proton pump inhibitor combined with two or more antibiotics, also alters gut microbiota composition, but consequences on metabolic health of the patients has been scarcely explored. Recent studies from our group showed that, despite decreasing gut bacterial diversity, conventional H. pylori eradication therapy is related to positive changes in glucose and lipid profiles. The mechanistic insights explaining these effects should also be addressed in future research. This review will deal with the role of gut microbiota as the linking factor between H. pylori infection and metabolic diseases, and discussed the impact that gut bacterial modulation by H. pylori eradication treatment can also have in host's metabolism. For this purpose, new evidence from the latest human studies published in more recent years will be analyzed.

Parenteral immunization with a cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) adjuvanted Helicobacter pylori vaccine induces protective immunity against H. pylori infection in mice

Under the trend of antibiotic resistance of H. pylori leading to the decrease of eradication rate, the development of a vaccine is the best choice to fight against H. pylori. In this study, we attempted to reduce the amounts of required antigens by using three different parenteral routes of immunization and an adjuvant cGAMP (cyclic guanosine monophosphate-adenosine monophosphate) to enhance the immunogenicity of the vaccine candidate. The immune protection and post-challenge immune responses were assessed and compared in mice immunized with recombinant Helicobacter pylori urease A, urease B, and neutrophil-activating protein adjuvanted with cGAMP. The gastric mucosal colonization by H. pylori was significantly reduced in mice immunized by intranasal and, to a less degree, subcutaneous route, but not by intramuscular route. All immunized mice, regardless of the route of immunization, displayed significant, but comparable, increases in antigen-specific serum IgG and mucosal IgA responses 5 weeks post-challenge. The magnitude of the vaccine-induced protection appeared to be associated with the level of antigen-specific Th1 and particularly Th17 responses, as IL-17 responses were only detected in intranasally immunized mice. Taken together, we explored and confirmed the possibility of using a novel adjuvant (cGAMP) to induce significant protective immunity with 10% of oral vaccine antigen dosage through parenteral immunization, especially intranasal immunization. This may provide an alternative approach to oral immunization for the development of effective H. pylori vaccines.

Helicobacter pylori Related Diseases and Osteoporotic Fractures (Narrative Review)

Osteoporosis (OP) and osteoporotic fractures (OFs) are common multifactorial and heterogenic disorders of increasing incidence. Helicobacter pylori (H.p.) colonizes the stomach approximately in half of the world's population, causes gastroduodenal diseases and is prevalent in numerous extra-digestive diseases known to be associated with OP/OF. The studies regarding relationship between H.p. infection (HPI) and OP/OFs are inconsistent. The current review summarizes the relevant literature on the potential role of HPI in OP, falls and OFs and highlights the reasons for controversies in the publications. In the first section, after a brief overview of HPI biological features, we analyze the studies evaluating the association of HPI and bone status. The second part includes data on the prevalence of OP/OFs in HPI-induced gastroduodenal diseases (peptic ulcer, chronic/atrophic gastritis and cancer) and the effects of acid-suppressive drugs. In the next section, we discuss the possible contribution of HPI-associated extra-digestive diseases and medications to OP/OF, focusing on conditions affecting both bone homeostasis and predisposing to falls. In the last section, we describe clinical implications of accumulated data on HPI as a co-factor of OP/OF and present a feasible five-step algorithm for OP/OF risk assessment and management in regard to HPI, emphasizing the importance of an integrative (but differentiated) holistic approach. Increased awareness about the consequences of HPI linked to OP/OF can aid early detection and management. Further research on the HPI-OP/OF relationship is needed to close current knowledge gaps and improve clinical management of both OP/OF and HPI-related disorders.

Clinical features of cardiac nodularity-like appearance induced by Helicobacter pylori infection

BACKGROUND

We have previously reported that Helicobacter pylori (H. pylori)-associated nodular gastritis could occur in both the antrum and the cardia. Cardiac nodularity-like appearance (hereafter, called as cardiac nodularity) had a high predictive accuracy for the diagnosis of H. pylori infection. In the previous study, we included only the patients who were evaluated for H. pylori infection for the first time, and excluded patients with a history of eradication. Therefore, the prevalence and clinical features of cardiac nodularity remains unknown.

AIM

To perform this cross-sectional study to explore the characteristics of cardiac nodularity.

METHODS

Consecutive patients who underwent esophagogastroduodenoscopy between May, 2017 and August, 2019 in the Toyoshima Endoscopy Clinic were enrolled in this study. We included H. pylori-negative, H. pylori-positive, and H. pylori-eradicated patients, and excluded patients with unclear H. pylori status and eradication failure. H. pylori infection was diagnosed according to serum anti-H. pylori antibody and the urea breath test or histology. Cardiac nodularity was defined as a miliary nodular appearance or the presence of scattered whitish circular small colorations within 2 cm of the esophagogastric junction. Nodularity was visualized as whitish in the narrow-band imaging mode. We collected data on the patients’ baseline characteristics.

RESULTS

A total of 1078 patients were finally included. Among H. pylori-negative patients, cardiac nodularity and antral nodularity were recognized in 0.14% each. Among H. pylori-positive patients, cardiac nodularity and antral nodularity were recognized in 54.5% and 29.5%, respectively. Among H. pylori-eradicated patients, cardiac nodularity and antral nodularity were recognized in 4.5% and 0.6%, respectively. The frequency of cardiac nodularity was significantly higher than that of antral nodularity in H. pylori-positive and -eradicated patients. The frequencies of cardiac nodularity and antral nodularity in H. pylori-eradicated patients were significantly lower than those in H. pylori-positive patients (P < 0.001). The patients with cardiac nodularity were significantly younger than those without cardiac nodularity (P = 0.0013). Intestinal metaplasia score of the patients with cardiac nodularity were significantly lower than those without cardiac nodularity (P = 0.0216). Among H. pylori-eradicated patients, the patients with cardiac nodularity underwent eradication significantly more recently compared with those without cardiac nodularity (P < 0.0001).

CONCLUSION

This report outlines the prevalence and clinical features of cardiac nodularity, and confirm its close association with active H. pylori infection.

PCR-based detection of Helicobacter spp. in animal facilities of a University in Rio de Janeiro, Brazil

Pathogenic microbial detection and control in laboratory animal facilities is essential to guarantee animal welfare, data validity and reproducibility. Helicobacter spp. are known to affect mice health, what may interfere with experimental outcomes. This study aimed to screen for Helicobacter spp. in mice from animal facilities in Rio de Janeiro, Brazil using a PCR-based method. Primers designed to specifically identify Helicobacter spp. were used to amplify feces or intestine DNA extracted of mice from four different animal facilities. The expected 375 base pairs (bp) amplicon was purified, sequenced and a similarity of 95% was observed when compared to deposited sequences of H. hepaticus and H. bilis. In our screening, Helicobacter spp. was detected in ~59% of fecal and ~70% of intestine samples. Our study is the first to screen for Helicobacter spp. in mouse facilities of a Rio de Janeiro University using a low cost, rapid molecular diagnostic test. Although Helicobacter spp. screening is not mandatory according to Brazilian animal welfare regulation it is recommended by institutional animal health monitoring programs guidelines worldwide, including ARRIVE, AAALAC and FELASA.

The effect of Channa striata extract and standard eradication regimen on asymmetric dimethylarginine in Helicobacter pylori gastritis rat model

BACKGROUND AND AIM

The presence of gastric mucosa or submucosa inflammation due to Helicobacter pylori leads to histological changes. Gastric injury, pro-inflammatory factors, and oxidative stress in H. pylori infection produce asymmetric dimethylarginine (ADMA), which are a competitive inhibitor of nitric oxide synthase. Investigations were carried out aimed at finding new drugs derived from natural products for the treatment of H. pylori. Channa striata is known to have in vitro anti-inflammatory and antimicrobial properties. This study aimed to investigate the effect of C. striata extract and a standard eradication regimen on ADMA levels and histological changes in the H. pylori gastritis rat model.

MATERIALS AND METHODS

Thirty-five male rats were randomly and equally divided into five groups. Group-1 was the negative control group and Groups-2 to 5 were H. pylori-infected groups. Groups-3 to 5 were administered C. striata extract, a standard eradication regimen, and a combination of standard eradication regimen and C. striata extract, respectively. Histological examination and serum ADMA levels were analyzed. The difference between groups was analyzed using the Kruskal-Wallis and one-way analysis of variance tests. The significance was p<0.05.

RESULTS

Serum ADMA levels and severity of gastritis were higher in infected groups compared to the negative control group (p<0.05). The severity of gastritis and mean ADMA levels in the group that received a single administration of the C. striata extract was higher than the others (p<0.05). Serum ADMA levels and severity of gastritis were significantly reduced in the group that received a combination of standard eradication regimen and C. striata extract (p<0.05).

CONCLUSION

Single administration of C. striata extract worsens the severity of gastritis and increased serum ADMA levels in the H. pylori gastritis rat model. The administration of a combination of standard eradication regimen and C. striata extract reduces serum ADMA levels and significantly improves the severity of H. pylori gastritis rat model.

The effect of snakehead fish extract supplementation to first-line eradication regimen on macrophage migration inhibitory factor (MIF) expression in rats induced by Helicobacter pylori infection

Objective:

This work was organized to assess macrophage migration inhibitory factor (MIF) expression in snakehead fish extract supplementation to first-line eradication regimen in rats induced by Helicobacter pylori infection.

Materials and methods:

A total of 28 manly rats were haphazardly isolated equally into four groups. Group-1 was the control negative, and groups-2–4 were H. pylori-infected groups. Group-2 was the control positive. Groups-3 and 4 were treated with first-line eradication regimen and first-line eradication regimen supplemented with snakehead fish extract, respectively. Immunoreactive scores (IRS) of MIF expression and eradication testing procedure were carried out. The comparison and difference between groups were analyzed by Kruskal–Wallis and post hoc Mann–Whitney U-test. A value of p < 0.05 was considered to be a limit of significance.

Results:

The average IRS of MIF expression in group-2 was the highest among other groups (p < 0.05). Group-4 (supplemented by snakehead fish extract) had a lower median value IRS of MIF expression compared to group-3 [1.0 (0.0–2.0) vs. 3.5 (2.0–6.0), p = 0.004].

Conclusion:

MIF expression was higher in rats induced by H. pylori infection. Snakehead fish extract supplementation to first-line eradication regimen significantly reduces more MIF expression compared to a single administration of first-line eradication regimen in rats induced by H. pylori infection.

The Association between ABCB1 C1236T/C3435T SNPs and H. pylori Infection among Jordanians

Infection with Helicobacter pylori (H. pylori) is very common and affecting about 50% of the worldwide population. Several genetic variations have been implicated in determining the clinical susceptibility to this infection. In the current study, we examined the association between C1236T (rs1045642) and C3435T (rs1045642) single nucleotide polymorphisms (SNPs) in the ABCB1 gene and the prevalence of H. pylori infection among Jordanians. A total of 412 subjects (257 H. pylori-positive cases and 155 H. pylori-negative controls) were recruited and participated in the study, and the genotyping of the ABCB1 gene was performed using RFLP-PCR techniques. A significant association was detected between C1236T and H. pylori infection (p < 0.01). The frequency of CT genotype was significantly higher in the positive cases (40.1%) compared to the controls (21.3%). In addition, the C3435T SNP was weakly associated with H. pylori infection (p = 0.077). Haplotype analysis of C1236T and C3435T SNPs showed that the TT haplotype was present in 22.7% of the positive cases compared to 30.7% of the negative controls (p < 0.05, odds ratio = 0.663, 95% CI: (0.483-0.911)). Consequently, the TT haplotype seems to decrease the risk of H. pylori infection. In conclusion, the current results suggest an association between ABCB1 SNPs and H. pylori infection in the Jordanian population.

Anti-Helicobacter pylori treatment can effectively improve the clinical remission rates of irritable bowel syndrome: a controlled clinical trial meta-analysis

Here we used a meta-analysis of several clinical trials to determine whether anti-Helicobacter pylori therapy has any positive effect on IBS patients. Here we compared the effective clinical remission rates between IBS patients treated with anti-H. pylori therapy and those who were not. This data would provide more clinical evidence regarding the efficacy of novel treatments and intervention points for IBS patients. Relevant studies were identified using keyword searches on various electronic databases, including PubMed, Embase, the Cochrane Central Register of Controlled Trials, CNKI, and CBM. Keywords included "helicobacter pylori" and "irritable bowel syndrome" among others. The literature was screened using relatively strict inclusion and exclusion criteria and RevMan 5.3.5 and Stata 15.1 software were used for meta-analysis and to assess publication bias and sensitivity. A total of ten studies met all of the inclusion criteria; these included 655 IBS patients with H. pylori infection, of these, 385 patients were in the experimental group and 270 patients were in the control group. A random-effects model was used to pool the odds ratios (ORs) with a 95% confidence interval (CIs) and the combined OR was 2.87 (95% CI: 1.74-4.72), p<0.0001. These findings suggest that anti-H. pylori therapy can effectively improve the remission rates of H. pylori-positive IBS patients. H. pylori infection is known to correlate with the incidence of IBS. Anti-H. pylori treatment can effectively improve the clinical remission rates of IBS patients. Whether this means that IBS patients should be actively treated with anti-H. pylori compounds as a novel strategy to improve the remission rates needs to be evaluated in vivo.

Two-week bismuth-containing quadruple therapy and concomitant therapy are effective first-line treatments for Helicobacter pylori eradication: A prospective open-label randomized trial

BACKGROUND

Increasing levels of antibiotic resistance have reduced the Helicobacter pylori (H. pylori) eradication rates afforded by the standard triple therapy. Thus, 2-wk first-line four-drug regimens must be considered.

AIM

To analyze the eradication rates of modified bismuth-containing quadruple therapy (mBCQT) and concomitant therapy (CT), the associated adverse events, and compliance.

METHODS

Patients infected with H. pylori were prospectively randomized to receive mBCQT or CT for 2 wk. mBCQT featured a proton pump inhibitor (PPI), bismuth, metronidazole, and tetracycline, taken twice daily. CT included a PPI, clarithromycin, metronidazole, and amoxicillin, taken twice daily. The ¹³C-urea breath test was performed no earlier than 4 wk after therapy concluded to confirm eradication. If either the histological or rapid urease test was positive, H. pylori infection was diagnosed.

RESULTS

The demographic characteristics of 68 patients who received mBCQT and 68 who received CT did not differ significantly. On intention-to-treat analysis, the eradication rate was 88.2% (60/68) in the mBCQT group and 79.4% (54/68) in the CT group (P = 0.162). By per-protocol analysis, the respective eradication rates were 98.4% (60/61) and 93.1% (54/58) (P = 0.199). More CT than mBCQT patients experienced adverse events [33.8% (23/68) mBCQT vs 51.5% (35/58) CT patients, respectively, P = 0.037]. All patients showed good compliance [85.3% (58/68) mBCQT vs 82.4% (56/68) CT patients, P = 0.641].

CONCLUSION

The H. pylori eradication rates of the 2-wk mBCQT and CT regimens are high. Most patients show good compliance, and more CT than mBCQT patients experience adverse events.