The Puzzle of Coccoid Forms of Helicobacter pylori: Beyond Basic Science.Antibiotics (Basel). 2020;9. [PMID: 32486473 DOI: 10.3390/antibiotics9060293]

Anti-Helicobacter pylori activity of nanocomposites from chitosan/broccoli mucilage/selenium nanoparticles

Helicobacter pylori can infect most people worldwide to cause hazardous consequences to health; the bacteria could not easily be controlled or disinfected. Toward exploring of innovative biocidal nanoformulations to control H. pylori, broccoli seeds (Brassica oleracea var. italica) mucilage (MBS) was employed for biosynthesizing selenium nanoparticles (MBS/SeNPs), which was intermingled with chitosan nanoparticles (NCT) to generate bioactive nanocomposites for suppressing H. pylori. The MBS could effectually generate and stabilize SeNPs with 13.61 nm mean diameter, where NCT had 338.52 nm mean diameter and positively charged (+ 39.62 mV). The cross-linkages between NCT-MBS-SeNPs were verified via infrared analysis and the nanocomposites from NCT:MBS/SeNPs at 1:2 (T1), 1:1 (T2) and 2:1 (T3) ratios had mean diameters of 204, 132 and 159 nm, respectively. The entire nanomaterials/composites exhibited potent anti- H. pylori activities using various assaying methods; the T2 nanocomposite was the utmost bactericidal agent with 0.08-0.10 mg/L minimal concentration and 25.9-27.3 mm inhibition zones. The scanning microscopy displayed the ability of nanocomposite to attach the bacterial cells, disrupt their membranes, and completely lyse them within 10 h. The NCT/MBS/SeNPs nanocomposites provided effectual innovative approach to control H. pylori.

Enhanced fatty acid biosynthesis by Sigma28 in stringent responses contributes to multidrug resistance and biofilm formation in Helicobacter pylori

The metabolic state of bacteria significantly contributes to their resistance to antibiotics; however, the specific metabolic mechanisms conferring antimicrobial resistance in Helicobacter pylori remain largely understudied. Employing transcriptomic and non-targeted metabolomics, we characterized the metabolic reprogramming of H. pylori when challenged with antibiotic agents. We observed a notable increase in both genetic and key proteomic components involved in fatty acid biosynthesis. Inhibition of this pathway significantly enhanced the antibiotic susceptibility of the sensitive and multidrug-resistant H. pylori strains while also disrupting their biofilm-forming capacities. Further analysis revealed that antibiotic treatment induced a stringent response, triggering the expression of the hp0560-hp0557 operon regulated by Sigma28 (σ28). This activation in turn stimulated the fatty acid biosynthetic pathway, thereby enhancing the antibiotic tolerance of H. pylori. Our findings reveal a novel adaptive strategy employed by H. pylori to withstand antibiotic stress.

Targeted nanotherapeutics for the treatment of Helicobacter pylori infection

Helicobacter pylori infection is involved in gastric diseases such as peptic ulcer and adenocarcinoma. Approved antibiotherapies still fail in 10 to 40% of the infected patients and, in this scenario, targeted nanotherapeutics emerged as powerful allies for H. pylori eradication. Nano/microparticles conjugated with H. pylori binding molecules were developed to eliminate H. pylori by either (i) blocking essential mechanisms of infection, such as adhesion to gastric mucosa or (ii) binding and killing H. pylori through the release of drugs within the bacteria or at the site of infection. Glycan antigens (as Lewis B and sialyl-Lewis X), pectins, lectins, phosphatidylethanolamine and epithelial cell membranes were conjugated with nano/microparticles to successfully block H. pylori adhesion. Urea-coated nanoparticles were used to improve drug delivery inside bacteria through H. pylori UreI channel. Moreover, nanoparticles coated with antibodies against H. pylori and loaded with sono/photosensitizers, were promising for their application as targeted sono/photodynamic therapies. Further, non-specific H. pylori nano/microparticles, but only active in the acidic gastric environment, coated with binders to bacterial membrane, extracellular polymeric substances or to high temperature requirement A protease, were evaluated. In this review, an overview of the existing nanotherapeutics targeting H. pylori will be given and their rational, potential to counteract infection, as well as level of development will be presented and discussed.

Novel therapeutic regimens against Helicobacter pylori: an updated systematic review

Helicobacter pylori (H. pylori) is a strict microaerophilic bacterial species that exists in the stomach, and H. pylori infection is one of the most common chronic bacterial infections affecting humans. Eradicating H. pylori is the preferred method for the long-term prevention of complications such as chronic gastritis, peptic ulcers, gastric mucosa-associated lymphoid tissue lymphoma, and gastric cancer. However, first-line treatment with triple therapy and quadruple therapy has been unable to cope with increasing antibacterial resistance. To provide an updated review of H. pylori infections and antibacterial resistance, as well as related treatment options, we searched PubMed for articles published until March 2024. The key search terms were "H. pylori", "H. pylori infection", "H. pylori diseases", "H. pylori eradication", and "H. pylori antibacterial resistance." Despite the use of antimicrobial agents, the annual decline in the eradication rate of H. pylori continues. Emerging eradication therapies, such as the development of the new strong acid blocker vonoprazan, probiotic adjuvant therapy, and H. pylori vaccine therapy, are exciting. However, the effectiveness of these treatments needs to be further evaluated. It is worth mentioning that the idea of altering the oxygen environment in gastric juice for H. pylori to not be able to survive is a hot topic that should be considered in new eradication plans. Various strategies for eradicating H. pylori, including antibacterials, vaccines, probiotics, and biomaterials, are continuously evolving. A novel approach involving the alteration of the oxygen concentration within the growth environment of H. pylori has emerged as a promising eradication strategy.

Pathohistological Changes in the Gastric Mucosa in Correlation with the Immunohistochemically Detected Spiral and Coccoid Forms of Helicobacter pylori

BACKGROUND

The coccoid form of Helicobacter pylori (H. pylori) is resistant to antibiotics. There are only a few studies that have analyzed the frequency of coccoid H. pylori in patients with gastritis. The aim of this work was to examine the correlation between the H. pylori form and the pathohistological characteristics of the stomach in patients with gastritis.

MATERIALS AND METHODS

This research was cross-sectional and focused on the gastric mucosa samples of 397 patients from one general hospital in Croatia. Two independent pathologists analyzed the samples regarding the pathohistological characteristics and the form of H. pylori.

RESULTS

There was a statistically significant difference in the gender of patients with H. pylori gastritis. Only the coccoid form of H. pylori was present in 9.6% of patients. There was a statistically significant difference in the frequency of a certain form of the bacterium depending on its localization in the stomach. The intensity of the bacterium was low in the samples where only the coccoid or spiral form was described. In cases of infection in the antrum, premalignant lesions and the coccoid form of H. pylori were more often present.

CONCLUSION

In the diagnosis of H. pylori infection, the determination of the form of the bacterium via immunohistochemistry should be included to increase the rate of eradication therapy and reduce the incidence of gastric malignancy.

Assessment of histology's performance compared with PCR in the diagnosis of Helicobacter pylori infection

Aim: Histology is the most widely used test to detect H. pylori. PCR is less used but allows the detection of both infection and antibiotics' resistance. Methods: We conducted a monocentric cross-sectional study, collecting 97 symptomatic patients to assess the diagnostic performance of histology in the detection of H. pylori infection compared with PCR. Results: Sensitivity of histology in comparison with PCR was 81.5% and specificity was 56.3%. A history of anti-H. pylori therapy intake, as well as the density of the bacterium on the gastric sample and the presence of gastric atrophy, were significantly correlated to the PCR's result in terms of H. pylori detection. Conclusion: Thus, histology can be considered as an efficient test compared with PCR in H. pylori detection.

Characterization of viable but nonculturable state of Campylobacter concisus

Campylobacter concisus is an opportunistic bacterial pathogen linked with a range of human diseases. The objective of this study was to investigate the viable but nonculturable (VBNC) state of the bacterium. To induce the VBNC state, C. concisus cells were maintained in sterilized phosphate-buffered saline at 4°C for three weeks. The VBNC cells were monitored using quantitative analysis by propidium monoazide (PMAxx) coupled with quantitative real-time PCR (PMAxx-qPCR), targeting the DNA gyrase subunit B gene. The results demonstrated that C. concisus ATCC 51562 entered the VBNC state in 15 days, while ATCC 51561 entered the VBNC state in 9 days. The viable cell counts, assessed by PMAxx-qPCR, consistently remained close to the initial level of 107 CFU ml-1, indicating a substantial portion of the cell population had entered the VBNC state. Notably, morphological analysis revealed that the VBNC cells became coccoid and significantly smaller. The cells could be resuscitated through a temperature increase in the presence of a highly nutritious growth medium. In conclusion, under environmental stress, most C. concisus cells converted to the VBNC state. The VBNC state of C. concisus may be important for its environmental survival and spread, and the presence of VBNC forms should be considered in environmental and clinical monitoring.

Quantification and cultivation of Helicobacter pylori (H. pylori) from various urban water environments: A comprehensive analysis of precondition methods and sample characteristics

Substantial evidence suggests that all types of water, such as drinking water, wastewater, surface water, and groundwater, can be potential sources of Helicobacter pylori (H. pylori) infection. Thus, it is critical to thoroughly investigate all possible preconditioning methods to enhance the recovery of H. pylori, improve the reproducibility of subsequent detection, and optimize the suitability for various water types and different detection purposes. In this study, we proposed and evaluated five distinct preconditioning methods for treating water samples collected from multiple urban water environments, aiming to maximize the quantitative qPCR readouts and achieve effective selective cultivation. According to the experimental results, when using the qPCR technique to examine WWTP influent, effluent, septic tank, and wetland water samples, the significance of having a preliminary cleaning step becomes more evident as it can profoundly influence qPCR detection results. In contrast, the simple, straightforward membrane filtration method could perform best when isolating and culturing H. pylori from all water samples. Upon examining the cultivation and qPCR results obtained from groundwater samples, the presence of infectious H. pylori (potentially other pathogens) in aquifers must represent a pressing environmental emergency demanding immediate attention. Furthermore, we believe groundwater can be used as a medium to reflect the H. pylori prevalence in a highly populated community due to its straightforward analytical matrix, consistent detection performance, and minimal interferences from human activities, temperature, precipitation, and other environmental fluctuations.

Dysbiosis by Eradication of Helicobacter pylori Infection Associated with Follicular Gastropathy and Pangastropathy

Dysbiosis plays an important role in the development of bacterial infections in the gastric mucosa, particularly Helicobacter pylori. The international guidelines for the treatment of H. pylori infections suggest standard triple therapy (STT). Nevertheless, because of the increasing resistance rates to clarithromycin, metronidazole has been widely considered in several countries. Unfortunately, the non-justified administration of antibiotics induces dysbiosis in the target organ. We characterized the gastric microbiota of patients diagnosed with follicular gastropathy and pangastropathy attributed to H. pylori infection, before and after the administration of STT with metronidazole. Dominant relative abundances of Cutibacterium were observed in pre-treatment patients, whereas H. pylori was observed at <11%, suggesting the multifactor property of the disease. The correlation of Cutibacterium acnes and H. pylori with gastric infectious diseases was also evaluated using quantitative real-time polymerase chain reaction. The dominance of C. acnes over H. pylori was observed in gastritis, gastropathies, and non-significant histological alterations. None of the microorganisms were detected in the intestinal metaplasia. Post-treatment alterations revealed an increase in the relative abundances of Staphylococcus, Pseudomonas, and Klebsiella. Non-H. pylori gastrointestinal bacteria can be associated with the initiation and development of gastric diseases, such as pathobiont C. acnes.

Pseudomonas aeruginosa biofilm exopolysaccharides: assembly, function, and degradation

The biofilm matrix is a fortress; sheltering bacteria in a protective and nourishing barrier that allows for growth and adaptation to various surroundings. A variety of different components are found within the matrix including water, lipids, proteins, extracellular DNA, RNA, membrane vesicles, phages, and exopolysaccharides. As part of its biofilm matrix, Pseudomonas aeruginosa is genetically capable of producing three chemically distinct exopolysaccharides - alginate, Pel, and Psl - each of which has a distinct role in biofilm formation and immune evasion during infection. The polymers are produced by highly conserved mechanisms of secretion, involving many proteins that span both the inner and outer bacterial membranes. Experimentally determined structures, predictive modelling of proteins whose structures are yet to be solved, and structural homology comparisons give us insight into the molecular mechanisms of these secretion systems, from polymer synthesis to modification and export. Here, we review recent advances that enhance our understanding of P. aeruginosa multiprotein exopolysaccharide biosynthetic complexes, and how the glycoside hydrolases/lyases within these systems have been commandeered for antimicrobial applications.

Dimethylaminododecyl Methacrylate-Incorporated Dental Materials Could Be the First Line of Defense against Helicobacter pylori

Oral cavity is an essential reservoir for H. pylori. We aimed to investigate the antibacterial effects of dimethylaminododecyl methacrylate (DMADDM) against H. pylori. Modified giomers were prepared by introducing 0%, 1.25% and 2.5% DMADDM monomers. Broth microdilution assay, spot assay, Alamer Blue assay, PMA-qPCR, crystal violet staining, scanning electron microscopy observation and live/dead bacterial staining were performed to evaluate the antibacterial and antibiofilm effects of DMADDM and modified giomers in vitro. Urease assay, qPCR, hematoxylin-eosin staining and ELISA were performed to evaluate the inflammation levels and colonization of H. pylori in vivo. In vitro experiments indicated that the minimum inhibitory concentration and minimum bactericidal concentration of DMADDM were 6.25 μg/mL and 25 μg/mL, respectively. It inhibited H. pylori in a dose- and time-dependent manner, and significantly reduced the expression of cagA, vacA, flaA and ureB. DMADDM-modified giomers inhibited the formation of H. pylori biofilm and reduced live cells within it. In vivo experiments confirmed that the pretreatment with DMADDM-modified dental resin effectively reduced the gastric colonization of oral-derived H. pylori, suppressed systemic and local gastric inflammation. DMADDM monomers and DMADDM-modified giomers possessed excellent antibacterial and antibiofilm effects on H. pylori. Pretreatment with DMADDM-modified giomers significantly inhibited the gastric infection by H. pylori.

Gastric xanthelasma is a warning sign for Helicobacter pylori infection, atrophic gastritis, and intestinal metaplasia

Background

Contradictory evidence suggested gastric xanthelasma (GX) was associated with some upper gastrointestinal (GI) diseases. Additionally, no research has been performed on the relationship between esophageal/duodenal xanthelasma and upper GI diseases.

Methods

Individuals who underwent esophagogastroduodenoscopy at Tongji Hospital, Tongji Medical College, participated in this retrospective study. This study evaluated whether the risk of GX or esophageal/duodenal xanthelasma was influenced by the following gastroesophageal diseases: superficial gastritis, gastric polyp, bile reflux, peptic ulcer, reflux esophagitis, Barrett's esophagus, esophageal cancer, atrophic gastritis (AG), intestinal metaplasia (IM), dysplasia, gastric cancer, and Helicobacter pylori (H. pylori) infection. Furthermore, subgroup analysis was conducted to establish the relationship between the number of GX and upper GI diseases.

Results

Of the 69,071 subjects reviewed, 1,220 (1.77%) had GX, and 54 (0.08%) had esophageal/duodenal xanthelasma. There was no difference in the prevalence of upper GI diseases between patients with and without esophageal/duodenal xanthelasma. Nevertheless, compared with non-xanthelasma patients, GX patients had a greater proportion of AG, IM, dysplasia, gastric cancer, and H. pylori infection and a lower incidence of superficial gastritis (p < 0.05). The multivariate logistic regression analysis indicated AG (OR = 1.83, 95%CI: 1.56-2.16), IM (OR = 2.42, 95%CI: 2.41-2.85), and H. pylori infection (OR = 1.32, 95%CI: 1.17-1.50) were independent risk factors for GX. In addition, patients with multiple GXs had a higher rate of AG and IM than those with single GX.

Conclusion

Esophageal/duodenal xanthelasma may not be associated with upper GI diseases, and further research is needed to support this hypothesis. Notably, GX, especially multiple GXs, may be a more easily detected warning sign of AG, IM, or H. pylori infection.

The possible role of Helicobacter pylori in liver diseases

According to previous studies, Helicobacter pylori infection is associated with liver disease. In order to better understand the risk of acquiring various liver diseases, we reviewed current knowledge on the impact of H. pylori on the onset, intensification, and progression of various liver diseases caused by the infection of H. pylori. It has been estimated that between 50 and 90% of people worldwide have been infected with H. pylori. The bacterium is mostly responsible for inflamed gastric mucosa, ulcers, and cancers associated with the gastric mucosa. Through the active antioxidant system in H. pylori, the bacteria can neutralize free radicals by synthesizing VacA, a toxin that causes cell damage and apoptosis. Furthermore, there is a possibility that CagA genes may play a role in cancer development. People who have been infected with H. pylori are likely to develop lesions in the skin, the circulation system, and the pancreas. Moreover, transferring blood from the stomach may allow H. pylori to colonize the liver. The bacterium worsened liver function during autoimmune inflammation, toxic injury, chronic HCV infection, chronic HBV infection, and liver cirrhosis. Increasing portal pressure, hyperammonemia, and esophageal varices may be associated with H pylori infection. As a result, it is crucial to diagnose and treat this infection in patients with H. pylori.

Novel approach for the inhibition of Helicobacter pylori contamination in yogurt using selected probiotics combined with eugenol and cinnamaldehyde nanoemulsions

Different strains of probiotics were screened in vitro to select the one with the highest anti-H. pylori activity. Three nanoemulsions of eugenol, cinnamaldehyde and their mixture were fabricated and tested also in vitro against the same pathogen. The selected probiotic strains, the nanoemulsion mixture and their combination were imbedded in a lab-manufactured yogurt which is deliberately contaminated with 6.0 log cfu/g H. pylori during manufacture. The inhibitory activity of all treatments on the growth of H. pylori and the other microorganisms in yogurt was evaluated during 21 days. Combining the selected probiotic strains with the nanoemulsion mixture in the contaminated yogurt reduced the count of H. pylori by 3.9 log cycle. The nanoemulsion showed lower inhibitory effect against the other microorganisms like probiotics, starter culture and total bacterial count in the tested yogurt, where their enumeration did not fall below 10⁶ cfu/g at the end of yogurt storage period.

Dual therapy for Helicobacter pylori infection

ABSTRACT

Bismuth-containing quadruple therapy (BQT) has long been recommended for Helicobacter pylori ( H. pylori ) eradication in China. Meanwhile, in the latest national consensus in China, dual therapy (DT) comprising an acid suppressor and amoxicillin has also been recommended. In recent years, the eradication rate of H. pylori has reached >90% using DT, which has been used not only as a first-line treatment but also as a rescue treatment. Compared with BQT, DT has great potential for H. pylori eradication; however, it has some limitations. This review summarizes the development of DT and its application in H. pylori eradication. The H. pylori eradication rates of DT were comparable to or even higher than those of BQT or standard triple therapy, especially in the first-line treatment. The incidence of adverse events associated with DT was lower than that with other therapies. Furthermore, there were no significant differences in the effects of dual and quadruple therapies on gastrointestinal microecology. In the short term, H. pylori eradication causes certain fluctuations in the gastrointestinal microbiota; however, in the long term, the gastrointestinal microbiota eventually returns to its normal state. In the penicillin-naïve population, patients receiving DT have a high eradiation rate, better compliance, lower incidence of adverse reactions, and lower primary and secondary resistance to amoxicillin. These findings suggest the safety, efficacy, and potential of DT for H. pylori eradication.

Antibacterial and antibiofilm activity of mannose-modified chitosan/PMLA nanoparticles against multidrug-resistant Helicobacter pylori

Because of the apparent stasis in antibiotic discoveries and the growth of multidrug resistance, Helicobacter pylori-associated gastric infections are difficult to eradicate. In the search for alternative therapy, the reductive amination of chitosan with mannose, followed by ionic gelation, produced mannose functionalized chitosan nanoparticles. Then, molecular docking and molecular dynamics (MD) simulations were conducted with H. pylori lectin (HPLectin) as a target protein involved in bacterium adherence to host cells, biofilm formation, and cytotoxicity. Changes in zeta potential and FTIR spectroscopy revealed that chitosan was functionalized with mannose. Time-kill, polystyrene adherence, and antibiofilm studies were utilized to assess nanoparticles as an alternative antibacterial treatment against a resistant gastric pathogen. Man-CS-Nps were discovered to have effective anti-adherence and biofilm disruption characteristics in suppressing the development of resistant H. pylori. In addition, bioimaging studies with CLSM, TEM, and SEM illustrated that Man-CS-Nps interacted with bacterial cells and induced membrane disruption by creating holes in the outer membranes of the bacterial cells, resulting in the leakage of amino acids. Importantly, molecular docking and 20 ns MD simulations revealed that Man-CS-Nps inhibited the target protein through slow-binding inhibition and hydrogen bond interactions with active site residues. As a consequence of the findings of this study, the Man-CS-Nps is an excellent candidate for developing alternative therapies for the increasing incidences of resistant gastric infections.

How Charge, Size and Protein Corona Modulate the Specific Activity of Nanostructured Lipid Carriers (NLC) against Helicobacter pylori

The major risk factor associated with the development of gastric cancer is chronic infection with Helicobacter pylori. The available treatments, based on a cocktail of antibiotics, fail in up to 40% of patients and disrupt their gut microbiota. The potential of blank nanostructured lipid carriers (NLC) for H. pylori eradication was previously demonstrated by us. However, the effect of NLC charge, size and protein corona on H. pylori-specific bactericidal activity herein studied was unknown at that time. All developed NLC formulations proved bactericidal against H. pylori. Although cationic NLC had 10-fold higher bactericidal activity than anionic NLC, they lacked specificity, since Lactobacillus acidophilus was also affected. Anionic NLC achieved complete clearance in both H. pylori morphologies (rod- and coccoid-shape) by inducing alterations in bacteria membranes and the cytoplasm, as visualized by transmission electron microscopy (TEM). The presence of an NLC protein corona, composed of 93% albumin, was confirmed by mass spectrometry. This protein corona delayed the bactericidal activity of anionic NLC against H. pylori and hindered NLC activity against Escherichia coli. Overall, these results sustain the use of NLC as a promising antibiotic-free strategy targeting H. pylori.

Recombinant Helicobacter pylori Vaccine Delivery Vehicle: A Promising Tool to Treat Infections and Combat Antimicrobial Resistance

Antimicrobial resistance (AMR) has become a global public health threat. Experts agree that unless proper actions are taken, the number of deaths due to AMR will increase. Many strategies are being pursued to tackle AMR, one of the most important being the development of efficient vaccines. Similar to other bacterial pathogens, AMR in Helicobacter pylori (Hp) is rising worldwide. Hp infects half of the human population and its prevalence ranges from <10% in developed countries to up to 90% in low-income countries. Currently, there is no vaccine available for Hp. This review provides a brief summary of the use of antibiotic-based treatment for Hp infection and its related AMR problems together with a brief description of the status of vaccine development for Hp. It is mainly dedicated to genetic tools and strategies that can be used to develop an oral recombinant Hp vaccine delivery platform that is (i) completely attenuated, (ii) can survive, synthesize in situ and deliver antigens, DNA vaccines, and adjuvants to antigen-presenting cells at the gastric mucosa, and (iii) possibly activate desired compartments of the gut-associated mucosal immune system. Recombinant Hp vaccine delivery vehicles can be used for therapeutic or prophylactic vaccination for Hp and other microbial pathogens.

A study on the diagnosis of the Helicobacter pylori coccoid form with artificial intelligence technology

Background

Helicobacter pylori (H. pylori) is an important pathogenic microorganism that causes gastric cancer, peptic ulcers and dyspepsia, and infects more than half of the world's population. Eradicating H. pylori is the most effective means to prevent and treat these diseases. H. pylori coccoid form (HPCF) causes refractory H. pylori infection and should be given more attention in infection management. However, manual HPCF recognition on slides is time-consuming and labor-intensive and depends on experienced pathologists; thus, HPCF diagnosis is rarely performed and often overlooked. Therefore, simple HPCF diagnostic methods need to be developed.

Materials and methods

We manually labeled 4,547 images from anonymized paraffin-embedded samples in the China Center for H. pylori Molecular Medicine (CCHpMM, Shanghai), followed by training and optimizing the Faster R-CNN and YOLO v5 models to identify HPCF. Mean average precision (mAP) was applied to evaluate and select the model. The artificial intelligence (AI) model interpretation results were compared with those of the pathologists with senior, intermediate, and junior experience levels, using the mean absolute error (MAE) of the coccoid rate as an evaluation metric.

Results

For the HPCF detection task, the YOLO v5 model was superior to the Faster R-CNN model (0.688 vs. 0.568, mean average precision, mAP); the optimized YOLO v5 model had a better performance (0.803 mAP). The MAE of the optimized YOLO v5 model (3.25 MAE) was superior to that of junior pathologists (4.14 MAE, p < 0.05), no worse than intermediate pathologists (3.40 MAE, p > 0.05), and equivalent to a senior pathologist (3.07 MAE, p > 0.05).

Conclusion

HPCF identification using AI has the advantage of high accuracy and efficiency with the potential to assist or replace pathologists in clinical practice for HPCF identification.

Helicobacter Pylori-Induced Gastric Infections: From Pathogenesis to Novel Therapeutic Approaches Using Silver Nanoparticles

Helicobacter pylori is the first formally recognized bacterial carcinogen and the most important single digestive pathogen responsible for the induction of gastroduodenal diseases such as gastritis, peptic ulcer, and, finally, gastric neoplasia. The recently reported high rates of antimicrobial drug resistance hamper the current therapies of H. pylori, with therapeutic failure reaching up to 40% of patients. In this context, new treatment options and strategies are urgently needed, but the successful development of these new therapeutic tools is conditioned by the understanding of the high adaptability of H. pylori to the gastric acidic environment and the complex pathogenic mechanism. Due to several advantages, including good antibacterial efficiency, possible targeted delivery, and long tissular persistence, silver nanoparticles (AgNPs) offer the opportunity of exploring new strategies to improve the H. pylori therapy. A new paradigm in the therapy of H. pylori gastric infections using AgNPs has the potential to overcome the current medical limitations imposed by the H. pylori drug resistance, which is reported for most of the current organic antibiotics employed in the classical therapies. This manuscript provides an extensive overview of the pathology of H. pylori-induced gastritis, gastric cancer, and extradigestive diseases and highlights the possible benefits and limitations of employing AgNPs in the therapeutic strategies against H. pylori infections.

Chitosan-curcumin complexation to develop functionalized nanosystems with enhanced antimicrobial activity against hetero-resistant gastric pathogen

With the apparent stagnation in the antibiotic discovery and the propagation of multidrug resistance, Helicobacter pylori associated gastric infections are hard to eradicate. In pursuance of alternative medicines, in this study, covalent modification of chitosan (CS) polymer with curcumin (Cur) was accomplished. Proton Nuclear Magnetic Resonance and Fourier Transform Infrared spectroscopy elucidated the covalent interaction between Cur and CS with characteristic peak of imine functional group (C=N). Scanning Electron Microscopy provided visual proof for surface topology, while size and zeta potential values further affirmed the development of curcumin functionalized chitosan nanosystems (Cur-FCNS). The complexation efficiency of CS with Cur was found as 70 ± 3% at an optimal ratio of 5:1 for CS and Cur, respectively. Cur-FCNS developed with ionic gelation and ultrasonication method demonstrated synergistic anti-H. pylori activity in growth-kinetics and anti-biofilm assays, which was superior to free Cur and even chitosan nanosystems. Under simulated gastric conditions, Cur-FCNS revealed cumulative-release of only 16 ± 0.8% till 40 h, which indicated its improved stability to interact with H. pylori. In silico findings affirmed high binding affinity of Cur-FCNS with multiple bacterial virulence factors. Thus, our results affirmed the exceptional potential of Cur-FCNS as next-generation alternative-medicine to treat resistant H. pylori.

Helicobacter pylori: an up-to-date overview on the virulence and pathogenesis mechanisms

Helicobacter pylori is an organism associated with ulcer disease and gastric cancer. The latter is one of the most prevalent malignancies and currently the fourth major cause of cancer-related deaths globally. The pathogen infects about 50% of the world population, and currently, no treatment ensures its total elimination. There has been an increase in our understanding of the pathophysiology and pathogenesis mechanisms of H. pylori over the years. H. pylori can induce several genetic alterations, express numerous virulence factors, and trigger diverse adaptive mechanisms during its adherence and colonization. For successful colonization and infection establishment, several effector proteins/toxins are released by the organism. Evidence is also available reporting spiral to coccoid transition as a unique tactic H. pylori uses to survive in the host's gastrointestinal tract (GIT). Thus, the virulence and pathogenicity of H. pylori are under the control of complex interplay between the virulence factors, host, and environmental factors. Expounding the role of the various virulence factors in H. pylori pathogenesis and clinical outcomes is crucial for vaccine development and in providing and developing a more effective therapeutic intervention. Here we critically reflect on H. pylori infection and delineate what is currently known about the virulence and pathogenesis mechanisms of H. pylori.

Next-Generation Sequencing-Based Study of Helicobacter pylori Isolates from Myanmar and Their Susceptibility to Antibiotics

Evaluation of Helicobacter pylori resistance to antibiotics is crucial for treatment strategy in Myanmar. Moreover, the genetic mechanisms involved remain unknown. We aimed to investigate the prevalence of H. pylori infection, antibiotic resistance, and genetic mechanisms in Myanmar. One hundred fifty patients from two cities, Mawlamyine (n = 99) and Yangon (n = 51), were recruited. The prevalence of H. pylori infection was 43.3% (65/150). The successfully cultured H. pylori isolates (n = 65) were tested for antibiotic susceptibility to metronidazole, levofloxacin, clarithromycin, amoxicillin, and tetracycline by Etest, and the resistance rates were 80%, 33.8%, 7.7%, 4.6%, and 0%, respectively. In the multidrug resistance pattern, the metronidazole–levofloxacin resistance was highest for double-drug resistance (16/19; 84.2%), and all triple-drug resistance (3/3) was clarithromycin–metronidazole–levofloxacin resistance. Twenty-three strains were subjected to next-generation sequencing to study their genetic mechanisms. Interestingly, none of the strains resistant to clarithromycin had well-known mutations in 23S rRNA (e.g., A2142G, A2142C, and A2143G). New type mutation genotypes such as pbp1-A (e.g., V45I, S/R414R), 23S rRNA (e.g., T248C), gyrA (e.g., D210N, K230Q), gyrB (e.g., A584V, N679H), rdxA (e.g., V175I, S91P), and frxA (e.g., L33M) were also detected. In conclusion, the prevalence of H. pylori infection and its antibiotic resistance to metronidazole was high in Myanmar. The H. pylori eradication regimen with classical triple therapy, including amoxicillin and clarithromycin, can be used as the first-line therapy in Myanmar. In addition, next-generation sequencing is a powerful high-throughput method for identifying mutations within antibiotic resistance genes and monitoring the spread of H. pylori antibiotic-resistant strains.

Empiric "Three-in-One" Bismuth Quadruple Therapy for Second-Line Helicobacter pylori Eradication: An Intervention Study in Southern Italy

The eradication of Helicobacter pylori (H. pylori) may be difficult due to antibiotic resistance. Indeed, after one failure, a second-line therapy is needed and a bismuth containing quadruple therapy (BQT) with a three-in-one capsule formulation is becoming very popular. Therefore, we aimed to evaluate effectiveness and safety of BQT as a second-line therapy. We recruited consecutive patients with one therapy failure. For ten days patients received the three-in-one BQT Pylera^® therapy, in combination with a proton-pump inhibitor (PPI), decided at the choice of the investigator, at full dose bid. The eradication rate was calculated by intention-to-treat (ITT) and per-protocol (PP)analyses and 95% confidence intervals (CI) were calculated. Seventy-three patients were recruited, 41 females and 32 males (mean age 53.0±13.1 years). Fifty-five patients failed triple therapy with amoxicillin and clarithromycin and the remaining 18 received sequential therapy. Seventy-two patients consumed at least 90% of the capsules, while only one did not complete the therapy due to adverse events (nausea and diarrhea). By ITT analysis, BQT was successful in 62 subjects (eradication rate 84.9%, 95%CI 76.7–93.1%). By PP analysis, the eradication rate was 86.1% (95%CI 78.1–94.1%).Adverse events were observed in 14 subjects (20.5%).In conclusion, our report confirmed that BQT is effective as an empiric second-line regimen.

What you always wanted to know about gastric MALT-lymphoma: a focus on recent developments

The stomach is the most common site of origin for extranodal lymphomas, with extranodal marginal zone B-cell of the mucosa associated lymphoid tissue (MALT-lymphoma) being the predominant subtype. MALT-lymphoma develops in mucosa associated lymphoid structures acquired by infection or chronic antigenic stimuli and may therefore arise in almost any organ of the human body. In spite of histopathologic similarities between various organs upon first glance, recent findings suggest pronounced differences between different sites, with a variety of features specific to gastric MALT-lymphoma. The objective of this review is to sum up the current knowledge on pathogenesis, molecular pathology, clinical presentation and therapeutic approaches to gastric MALT-lymphoma with in-depth discussion of recent developments.

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 in Human Stomach: The Inconsistencies in Clinical Outcomes and the Probable Causes

Pathogenic potentials of the gastric pathogen, Helicobacter pylori, have been proposed, evaluated, and confirmed by many laboratories for nearly 4 decades since its serendipitous discovery in 1983 by Barry James Marshall and John Robin Warren. Helicobacter pylori is the first bacterium to be categorized as a definite carcinogen by the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO). Half of the world’s population carries H. pylori, which may be responsible for severe gastric diseases like peptic ulcer and gastric cancer. These two gastric diseases take more than a million lives every year. However, the role of H. pylori as sole pathogen in gastric diseases is heavily debated and remained controversial. It is still not convincingly understood, why most (80–90%) H. pylori infected individuals remain asymptomatic, while some (10–20%) develop such severe gastric diseases. Moreover, several reports indicated that colonization of H. pylori has positive and negative associations with several other gastrointestinal (GI) and non-GI diseases. In this review, we have discussed the state of the art knowledge on “H. pylori factors” and several “other factors,” which have been claimed to have links with severe gastric and duodenal diseases. We conclude that H. pylori infection alone does not satisfy the “necessary and sufficient” condition for developing aggressive clinical outcomes. Rather, the cumulative effect of a number of factors like the virulence proteins of H. pylori, local geography and climate, genetic background and immunity of the host, gastric and intestinal microbiota, and dietary habit and history of medicine usage together determine whether the H. pylori infected person will remain asymptomatic or will develop one of the severe gastric diseases.

Isolation Method and Characterization of Outer Membranes Vesicles of Helicobacter pylori Grown in a Chemically Defined Medium

Outer membrane vesicles (OMVs) are small vesicles constitutively shed by all Gram-negative bacterium, which have been proposed to play a role in Helicobacter pylori persistence and pathogenesis. The methods currently available for the isolation of H. pylori OMVs are diverse and time-consuming, raising the need for a protocol standardization, which was the main aim of this study. Here, we showed that the chemically defined F12 medium, supplemented with cholesterol, nutritionally supports bacterial growth and maintains H. pylori viability for at least 72 h. Additionally, we developed an abridged protocol for isolation of OMVs from these bacterial cultures, which comprises a low-speed centrifugation, supernatant filtration through a 0.45 μm pore, and two ultracentrifugations for OMVs’ recovery and washing. Using this approach, a good yield of highly pure bona fide OMVs was recovered from cultures of different H. pylori strains and in different periods of bacterial growth, as assessed by nanoparticle tracking analysis, transmission electron microscopy (TEM), and proteomic analyses, confirming the reliability of the protocol. Analysis of the proteome of OMVs isolated from H. pylori F12-cholesterol cultures at different time points of bacterial growth revealed differentially expressed proteins, including the vacuolating cytotoxin VacA. In conclusion, this work proposes a time- and cost-efficient protocol for the isolation of H. pylori OMVs from a chemically defined culture medium that is suitable for implementation in research and in the biopharmaceutical field.

Helicobacter pylori Infection

Helicobacter pylori infection remains one of the most prevalent infections worldwide, causing significant morbidity and mortality from gastric malignancies and peptic ulcers. This article provides a summary of the microbiology and pathogenesis of this bacterium, emphasizing the complex and protean effects of H pylori on gastric epithelial cells, including stem and progenitor populations, and evasion of host immune defenses. Increasing antibiotic resistance has made management more challenging. This article discusses the appropriate diagnostic modality for different clinical scenarios, and the evolving treatment of H pylori infections, including the use of antibiotic susceptibility testing to aid regimen selection.

Antibacterial activity of Hibiscus rosa-sinensis L. red flower against antibiotic-resistant strains of Helicobacter pylori and identification of the flower constituents

Utilization of plant resources for treatment of Helicobacter pylori infections is one of the appealing approaches as rapid emergence of antibiotic-resistant strains is occurring throughout the world. Ethanol extract and its fractions from Hibiscus rosa-sinensis red flower were assessed for antibacterial and urease inhibitory activities towards forty-three clinical strains and two reference strains of H. pylori. The ethyl acetate fraction exhibited the most potent bacteriostatic activity with minimum inhibitory concentrations (MICs) of 0.2-0.25 mg/mL and minimum bactericidal concentrations (MBCs) of 1.25-1.5 mg/mL against all test strains, including forty-three strains resistant to one to four antibiotics, azithromycin (MICs, 8-256 µg/mL), erythromycin (MICs, 8-128 µg/mL), levofloxacin (MICs, 8-256 µg/mL), and/or metronidazole (MICs, 8-256 µg/mL). The fraction had similar antibacterial activities toward these test strains suggesting the preparation and the antibiotics do not have a common mechanism of anti-H. pylori activity. The fraction also had stronger effects on biofilm formation, morphological conversion, and urease activity of H. pylori than the other fractions and the ethanol extract. These flower preparations were non-toxic to three human cell lines, and nine compounds were also isolated and identified from the ethyl acetate fraction. In vivo research needs to be conducted to confirm the potential usefulness of H. rosa-sinensis flower and its constituents for effective prevention and treatment of H. pylori disease.

Real-time EndoFaster improves Helicobacter pylori detection in chronic active gastritis

Helicobacter pylori is the most frequent cause of chronic active gastritis (CAG), namely the first step for gastric cancer development. When infection is not detected at histology, another test is advised. EndoFaster is novel device that reveal the presence of H. pylori by determining ammonium concentration in the gastric juice during endoscopy. We evaluated whether this test may improve etiological diagnosis in CAG patients. In 595 consecutive patients who underwent upper endoscopy gastric juice was analysed with EndoFaster and standard biopsies were taken. CAG with typical bacteria was detected in 102 (17.1%) patients, and CAG without H. pylori was found in 36 (6.3%) cases. EndoFaster detected the infection in 22 (61.1%) of these patients. Neither ongoing proton pump inhibitor therapy nor previous eradication therapy affect the test accuracy. By using EndoFaster, another test to search for the infection in H. pylori-negative CAG patients may be avoided in more than 60% of cases, impacting on both patients discomfort and health resources use.

Randomized controlled study on the effects of triple therapy including vonoprazan or rabeprazole for the second-line treatment of Helicobacter pylori infection

BACKGROUND AND AIM

Inhibition of gastric acid secretion is important for eradicating Helicobacter pylori. Vonoprazan (VPZ) is a strong, long-lasting inhibitor of gastric acid secretion. Studies that examined the effectiveness of VPZ-based triple therapy in second-line treatment have been performed. However, there have been no randomized controlled studies to compare the effect between VPZ-based triple therapy and proton pump inhibitor (PPI)-based triple therapy in second-line treatment, and it is not known which is more effective between VPZ-based and PPI-based therapies. This study aimed to compare the effectiveness of second-line triple therapies including VPZ or rabeprazole (RPZ) as the PPI.

METHODS

Eligible patients with H. pylori infection who failed first-line triple therapy were assigned randomly to the VPZ [VPZ40 mg/day, amoxicillin (AMPC) 1500 mg/day, metronidazole (MNZ) 500 mg/day] or RPZ (RPZ20 mg/day, AMPC1500 mg/day, MNZ500 mg/day) group. A ¹³C-urea breath test result of less than 2.5% was considered as successful eradication.

RESULTS

In total, 46 and 41 patients were analyzed as intention to treat (ITT) and per protocol (PP), respectively. Eradication rates in the VPZ and RPZ groups were 73.9% [95% confidence interval (CI) 51.6-89.8%] and 82.6% (95% CI 61.2-95.0%) based on ITT analysis, respectively (p = 0.72). Based on PP analysis, the eradication rates in the VPZ and RPZ groups were 89.5% (95% CI 66.9-98.7%) and 86.4% (95% CI 65.1-97.1%), respectively (p = 1.00). Two patients in the VPZ group and one in the RPZ group discontinued treatment due to side effects (p = 1.00).

CONCLUSION

There were no significant differences in efficacy and safety between second-line therapies including VPZ or RPZ.