Search Results (247)

Helicobacter pylori is a well-established causative agent of gastritis, peptic ulcers, gastric adenocarcinoma, and primary gastric lymphoma. It colonizes the human stomach and expresses numerous virulent factors that influence disease progression. Among these factors is the cytotoxin vacA gene, which encodes the vacuolating capacity of the cytotoxin and plays a key role in the bacterium’s pathogenic potential. This study investigated the allelic diversity of the vacA among H. pylori strains infecting patients in Jordan with various gastric conditions and examined potential associations between vacA s-and m- genotypes, histopathological and endoscopic findings, and the development of gastric diseases. Gastric biopsies were collected from 106 patients at two hospitals in Jordan who underwent endoscopic examination. The collected biopsies for each patient were subjected to histopathological assessment, urease detection using the Rapid Urease Test (RUT), a diagnostic test for H. pylori, and molecular detection of the vacA gene and its s and m alleles. The histopathology reports indicated that 83 of 106 patients exhibited gastric disorders, of which 81 samples showed features associated with H. pylori infection. The RUT was positive in 76 of 106 with an accuracy of 93.8%. Real-time polymerase chain reaction (RT-PCR) targeting the 16S rRNA gene confirmed the presence of H. pylori in 79 of 81 histologically diagnosed cases as infected (97.5%), while the vacA gene was detected only in 75 samples (~95%). To explore genetic diversity, PCR-amplified fragments underwent sequence analysis of the vacA gene. The m-allele was detected in 58 samples (73%), the s-allele was detected in 45 (57%), while both alleles were not detected in 13% of samples. The predominant genotype combination among Jordanians was vacA s2/m2 (50%), significantly linked to mild chronic gastritis, followed by s1/m2 (35%) and s1/m1 (11.8%) which are linked to severe gastric conditions including malignancies. Age-and gender-related differences in vacA genotype were observed with less virulent s2m2 and s1m2 genotypes predominating in younger adults specially males, while the more virulent m1 genotypes were found exclusively in females and middle-aged patients. Genomic sequencing revealed extensive diversity within H. pylori, likely reflecting its long-standing co-evolution with human hosts in Jordan. This genetic variability plays a key role in modulating virulence and influencing clinical outcomes. Comprehensive characterization of vacA genotypic variations through whole-genome sequencing is essential to enhance diagnostic precision, strengthen epidemiological surveillance, and inform targeted therapeutic strategies. While this study highlights the significance of the vacA m and s alleles, future research is recommended in order to investigate the other vacA allelic variations, such as the i, d, and c alleles, to achieve a more comprehensive understanding of H. pylori pathogenicity and associated disease severity across different strains. These investigations will be crucial for improving diagnostic accuracy and guiding the development of targeted therapeutic strategies. Full article

Background/Objectives: Helicobacter pylori (H. pylori) is a common gastric pathogen linked to gastritis, gastroduodenal ulcers, and gastric cancer. Rising antimicrobial resistance (AMR) poses challenges for effective treatment and has prompted the WHO to classify H. pylori as a high-priority pathogen. This study aimed to detect the prevalence of AMR genes in H. pylori-positive gastric samples from patients in Algarve, Portugal, where regional data is scarce. Methods: Eighteen H. pylori-positive gastric biopsy samples from patients undergoing upper gastrointestinal endoscopy were analyzed. PCR and sequencing were used to identify genes associated with resistance to amoxicillin (Pbp1A), metronidazole (rdxA, frxA), tetracycline (16S rRNA mutation) and clarithromycin (23S rRNA). Sequence identity and homologies were verified using tBLASTx and the Comprehensive Antibiotic Resistance Database (CARD). Results: Out of the 18 H. pylori-positive samples, 16 (88.9%) contained at least one AMR gene. The most frequent genes were rdxA (83.3%) and frxA (66.7%) for metronidazole resistance, and the 16S rRNA mutation (66.7%) for tetracycline. Resistance to amoxicillin and clarithromycin was detected in 27.8% and 16.7% of cases, respectively. Most samples (72.2%) had multiple resistance genes. A significantly strong association was found between female sex and the presence of the rdxA gene (p = 0.043). Conclusions: The study reveals a high prevalence of H. pylori resistance genes in Algarve, particularly against metronidazole and tetracycline. These findings highlight the need for local surveillance and tailored treatment strategies. Further research with larger populations is warranted to assess regional resistance patterns and improve eradication efforts. Full article

Helicobacter pylori infection represents one of the most prevalent and persistent bacterial infections worldwide, closely linked to a spectrum of gastroduodenal diseases, including chronic gastritis, peptic ulceration, and gastric cancer. Recent advances have shed light on the critical role of endogenous lectins, particularly galectins, in modulating host–pathogen interactions within the gastric mucosa. Galectins are β-galactoside-binding proteins with highly conserved structures but diverse biological functions, ranging from regulation of innate and adaptive immunity to modulation of cell signaling, apoptosis, and epithelial integrity. This review provides a comprehensive synthesis of current knowledge on the involvement of key galectin family members—especially Galectin-1, -2, -3, -8, and -9—in the context of H. pylori infection. Their dual roles in enhancing mucosal defense and facilitating bacterial persistence are examined along with their contributions to immune evasion, inflammation, and gastric carcinogenesis. Understanding the interplay between galectins and H. pylori enhances our knowledge of mucosal immunity. This interaction may also reveal potential biomarkers for disease progression and identify novel therapeutic targets. Modulating galectin-mediated pathways could improve outcomes in H. pylori-associated diseases. Full article

H. pylori infects over half of the global population and is associated with various gastric and extra-gastric diseases. Other species, such as zoonotic non-Helicobacter pylori Helicobacters (NHPHs), have shown similar associations with gastritis and MALT lymphoma and H. pylori-negative cases with gastric disease have been identified, including gastric MALT lymphoma, chronic gastritis, and gastroduodenal ulcers. Accurate identification of these species is of great relevance but remains challenging using conventional diagnostic methods. This cross-sectional study aimed to determine the prevalence of H. pylori and NHPH infections, comparing standard histological protocols with molecular techniques. Between December 2024 and February 2025, 54 adult patients undergoing upper gastrointestinal endoscopy (UGE) with gastric biopsy in three hospitals in Algarve, Portugal were recruited. Endoscopic assessment was performed, and gastric biopsies were collected for histological and molecular analysis. DNA was extracted from antral biopsies and analyzed by conventional PCR to detect H. pylori and NHPH. H. pylori diagnostic techniques were compared, descriptive plus statistical analysis was performed, and p-values < 0.05 were considered to be statistically significant. Fifty-four patients were included in the study, with 51.9% of them presenting symptoms. Endoscopic gastritis was observed in 66.7% of patients, while histological gastritis was present in 88.9%, with statistically significant differences between the two diagnostic techniques (p = 0.004). Helicobacter spp. were identified in 44.4% (24/54) of the patients. H. pylori was detected in 42.6% of the patients by Modified Giemsa stain and in 33.3% by PCR. H. bizzozeronii was found in 35.9% of the patients, with 22.2% showing mixed infections. This study reveals a significant prevalence of Helicobacter spp. in patients from the Algarve region, with both H. pylori and zoonotic H. bizzozeronii detected. This is the first report of H. bizzozeronii DNA detection in gastric biopsies via PCR from patients undergoing UGE in Portugal, highlighting the need to consider NHPH in clinical diagnosis. It is important to include molecular methods in routine diagnostics and the need for broader studies to assess regional and national trends in Helicobacter infections besides H. pylori. Full article

Traditionally, Helicobacter pylori (HP) gastritis has been diagnosed by pathologists through the examination of gastric biopsies using optical microscopy with standard hematoxylin and eosin (H&E) staining. However, with the adoption of digital pathology, the identification of HP faces certain limitations, particularly due to insufficient resolution in some scanned images. Moreover, interobserver variability has been well documented in the traditional diagnostic approach, which may further complicate consistent interpretation. In this context, deep convolutional neural network (DCNN) models are showing promising results in the automated detection of this infection in whole-slide images (WSIs). The aim of the present article is to detect the presence of HP infection from our own institutional dataset of histopathological gastric biopsy samples using different pretrained and recognized DCNN and AutoML approaches. The dataset comprises 100 H&E-stained WSIs of gastric biopsies. HP infection was confirmed previously using immunohistochemical confirmation. A total of 45,795 patches were selected for model development. InceptionV3, Resnet50, and VGG16 achieved AUC (area under the curve) values of 1. However, InceptionV3 showed superior metrics such as accuracy (97%), recall (100%), F1 score (97%), and MCC (93%). BoostedNet and AutoKeras achieved accuracy, precision, recall, specificity, and F1 scores less than 85%. The InceptionV3 model was used for external validation, and the predictions across all patches yielded a global accuracy of 78%. In conclusion, DCNN models showed stronger potential for diagnosing HP in gastric biopsies compared with the auto ML approach. However, due to variability across pathology applications, no single model is universally optimal. A problem-specific approach is essential. With growing WSI adoption, DL can improve diagnostic accuracy, reduce variability, and streamline pathology workflows using automation. Full article

Helicobacter pylori (H. pylori) is one of the most prevalent chronic bacterial infections globally, significantly contributing to gastritis, peptic ulcers, and gastric malignancies. Its pathogenesis involves a complex array of virulence factors—including cagA, vacA, and urease—which facilitate mucosal colonization, immune evasion, and persistent inflammation. A major challenge in vaccine development is the bacterium’s ability to manipulate both innate and adaptive immune responses, resulting in limited natural clearance and long-term persistence. This review synthesizes H. pylori pathogenesis and host immune dynamics, highlighting their implications for vaccine design. By elucidating the molecular and cellular mechanisms underlying host–pathogen interactions, we explore how these insights inform antigen selection, adjuvant optimization, and delivery strategies. By integrating basic science with translational objectives, this review aims to support the development of an effective H. pylori vaccine, addressing global health needs, particularly in regions with a high infection burden and limited access to treatment. Full article

Background and Objectives: Chronic mucosal infection with Helicobacter pylori (H. pylori) plays a key role in the development of gastroduodenal disorders such as chronic gastritis, peptic ulcers, gastric lymphoma, and gastric cancer by triggering local immune responses and inducing hypoxic and inflammatory conditions in the gastric mucosa. This study aims to evaluate the potential diagnostic value of hypoxia-inducible factors HIF-1α and HIF-2α, along with transmembrane prolyl 4-hydroxylase (P4H-TM), as biomarkers in H. pylori-positive patients. Additionally, the study investigates the association between these markers and alterations in lipid profiles, as well as their involvement in the molecular mechanisms underlying gastric conditions like gastritis, particularly in the context of H. pylori infection. Materials and Methods: This study was conducted at Istanbul Avcılar Murat Kölük State Hospital’s General Surgery Outpatient Clinic. A total of 60 participants were included: 40 patients diagnosed with chronic gastritis (20 H. pylori-positive and 20 H. pylori-negative) and 20 healthy controls confirmed negative by 13C-urea breath test. Blood samples were collected for ELISA analysis of HIF-1α, HIF-2α, and P4H-TM levels. Additionally, lipid profiles were measured and compared among the groups. Results: No significant differences were found among the groups in terms of demographic factors such as age, sex, or body mass index (BMI). However, significant variations were observed in the levels of HIF-1α, HIF-2α, and P4H-TM across all groups (p < 0.001 for each marker). These markers were substantially elevated in the H. pylori-positive gastritis group compared to both the H. pylori-negative and healthy control groups. Receiver Operating Characteristic (ROC) curve analysis revealed that all evaluated markers exhibited strong diagnostic accuracy in differentiating H. pylori-positive individuals from other groups. HIF-1α (AUC: 0.983) and HIF-2α (AUC: 0.981) both achieved 100% sensitivity with specificities of 93.3% and 91.1%, respectively. P4H-TM showed an AUC of 0.927, with 85% sensitivity and 95.6% specificity. Conclusions: These findings indicate that HIF-1α, HIF-2α, and P4H-TM may serve as effective biomarkers for diagnosing H. pylori-positive patients and may be linked to changes in lipid metabolism. The elevated expression of these markers in response to H. pylori infection highlights their potential roles in the inflammatory and hypoxic pathways that contribute to the pathogenesis of gastric diseases such as gastritis. Full article

Helicobacter pylori (H. pylori) infection is a leading cause of gastritis, peptic ulcers, and gastric cancer, affecting more than half of the global population. Its persistence in the acidic gastric environment and its ability to evade host immunity present major treatment challenges. Although antibiotics remain the standard therapy, rising antimicrobial resistance has reduced treatment efficacy, prompting the search for alternative and adjunct approaches. Emerging therapies include probiotics, antimicrobial peptides (AMPs), and plant-derived compounds, which target H. pylori through membrane disruption, immunomodulation, or direct antimicrobial activity. Novel drug delivery systems and microbiota-sparing interventions are also being investigated. Additionally, vaccine development offers a promising strategy for long-term protection, though challenges related to antigenic variability and host-specific responses remain. Despite these advances, treatment variability and the limited clinical validation of alternatives hinder progress. A multifaceted approach integrating microbiome research, host–pathogen interactions, and new therapeutic agents is essential for future success. Full article

Helicobacter pylori (H. pylori) is regarded as a significant risk factor for gastritis, peptic ulcer disease, and gastric cancer. However, the increasing resistance of H. pylori strains has resulted in low eradication rates and ineffective treatments. Herein, we report on identification of a new quipazine derivative—compound 9c (N-(3-chlorobenzyl)-2-(piperazin-1-yl)quinolin-4-amine), which displayed antibacterial properties (MIC range 2–4 µg/mL) against H. pylori CagA-positive reference strains associated with an increased risk of gastric cancer, including metronidazole-resistant ATCC 43504, clarithromycin-resistant ATCC 700684 and susceptible J99 strain, as well as clinical, multidrug-resistant isolate (3CML, resistant to clarithromycin, metronidazole and levofloxacin). Compound 9c showed bacteriostatic activity (MBC/MIC ratio > 4), demonstrated antibiofilm-forming properties and prevented auto-aggregation of microbial cells. It also displayed an additive effect in ½ MIC (2 µg/mL) when administered with clarithromycin and/or metronidazole. Compound 9c had no impact on gut microbiota reference strains of S. aureus, E. coli, E. faecalis and L. paracasei as well as no hemolytic activity against sheep erythrocytes. Finally, by reducing the viability of the SNU-1 human gastric cancer cell line (IC₅₀ = 3.28 μg/mL), compound 9c might offer important implications regarding the oncogenic characteristics of cagA+ H. pylori strains. Full article

Introduction: Inlet patch (IP) is a congenital anomaly characterized by gastric heterotopia in the cervical esophagus. While extensively described in adults, it remains poorl characterized in pediatric populations. Material and Methods: This retrospective, single-center study included all pediatric patients (0–14 years) diagnosed with IP between 2018 and 2025. Sociodemographic and clinical data were collected. A blinded pathologist assessed the presence and severity of inflammation within the IP. Results: Nine patients (median age, 12 years; range, 6–14 years) were included, with 78% beingmale. Cervical esophageal symptoms were identified in 67%, primarily dysphagia and gastroesophageal reflux disease-related complaints, although concomitant conditions such as eosinophilic esophagitis were frequently present. Three patients had symptoms potentially attributable to IP (33%). Endoscopic examination revealed characteristic well-demarcated salmon-red plaques in all patients, with multiple lesions observed in three cases. Histology confirmed gastric heterotopia with varying degrees of chronic inflammation in all cases. A potential association was observed between the severity of gastritis in the stomach, the severity of inflammation in the IP, and the presence of H. pylori, with 75% of patients with moderate-to-severe IP inflammation also exhibiting gastric H. pylori-associated gastritis. All patients except one received proton pump inhibitors, and symptoms improved in all cases. Conclusions: A thorough and targeted examination of the cervical esophagus significantly increased IP detection at our center, with most cases (89%) being diagnosed in the last 12 months. While mostly asymptomatic and incidental, IP can be symptomatic. In this case, series, we found a possible association between the severity of inflammation in the IP, the severity of gastritis, and the presence of H. pylori. Further studies are needed to define the clinical significance of pediatric IP and optimal management. Full article

Helicobacter pylori (H. pylori), a prevalent human pathogen affecting nearly half the global population, is a major contributor to chronic gastritis, peptic ulcer, and gastric cancer. H. pylori develops biofilms (BFs) allowing bacteria to evade the immune response. Differences in composition between planktonic and biofilm cells influence the host’s immune response, yet the specific biofilm components modulating this response remain uncharacterized. Considering the above, this study evaluated the effect of in vitro-generated H. pylori BF on the antibacterial activity of neutrophils. This work utilized sonication to obtain disaggregated H. pylori BF (d-BF-Hp) to challenge human neutrophils, assessing their bactericidal and phagocytic activity against Staphylococcus aureus. S. aureus survival in the presence of neutrophils was enhanced by 10 μg/mL of d-BF-Hp’s protein. Conversely, S. aureus survival was significantly lower at 30 µg/mL compared to 10 µg/mL d-BF-Hp. Furthermore, 10 and 30 µg/mL of d-BF-Hp significantly reduced the neutrophil phagocytosis rate. Our findings suggest that d-BF-Hp components diminish neutrophil bactericidal activity, although this effect was not observed at higher d-BF-Hp concentrations. Increased d-BF-Hp concentrations proportionally reduced neutrophil phagocytic capacity. Future work should explore the mechanisms underlying the alteration of neutrophil microbicidal properties. Full article

Background: This study aims to investigate the association between pyroptosis and the outer membrane virulence factor of H. pylori in patients with gastritis and ulcers. Methods: DNA, RNA, and protein were extracted from a single tissue sample taken from the antrum region of the stomach of volunteer patients. The expression of bacterial outer membrane virulence genes was analyzed at the gene level, and the expression levels of key pyroptosis markers were compared between H. pylori-infected and uninfected gastritis and ulcer patient groups. Results: H. pylori infection induced significant alterations in the expression levels of pyroptosis markers, including ASC, NLRP3, caspase-1, GSDMD, IL-18, and IL-1β, indicating a strong association with gastritis and ulcer pathology. Statistically significant correlations were observed between elevated levels of these markers and the activation of caspase-1 across different patient cohorts, supporting effective detection of pyroptosis. Both pro and active forms of caspase-1, GSDMD, IL-18, and IL-1β were assessed, revealing pyroptotic activity in specific patient samples. The vacA m2 allele showed a distinct ASC response in gastritis versus ulcer patients and was associated with increased GSDMD expression in ulcerative cases. Along with the babB gene, this allele appears to play a critical role in the interaction between H. pylori virulence and host pyroptotic responses. A statistically significant negative association was identified between the presence of the H. pylori alpA gene and Gasdermin D expression (odds ratio = 0, p < 0.01), suggesting that Gasdermin D was absent in all alpA-positive samples. Conclusion: This study provides novel insights into the interrelation between the virulence factors of H. pylori and pyroptosis in gastritis and ulcer diseases. Our findings demonstrate that H. pylori infection significantly alters the expression levels of pyroptosis markers, including ASC, NLRP3, caspase-1, GSDMD, IL-18, and IL-1β, in gastric tissues. Notably, the vacA m2 allele was associated with a differential response in ASC expression among patients with gastritis and ulcers, correlating with increased GSDMD levels in ulcerative conditions. The presence of the H. pylori alpA gene is markedly associated with the lack of Gasdermin D activation, indicating a possible suppressive function or immune evasion tactic. These results underscore the critical role of H. pylori virulence determinants in modulating pyroptosis and suggest that understanding this relationship may pave the way for developing targeted therapeutic strategies to mitigate H. pylori-associated pathologies. Full article

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonizes the human stomach and is associated with several gastric diseases, including gastritis, peptic ulcer disease, and gastric cancer. The bacterium’s ability to thrive in the harsh gastric environment is due, to some extent, to its stress response mechanisms, with its heat shock proteins (HSPs) playing a putative, yet not fully understood, role in these adaptive processes. HSPs are a family of molecules, highly conserved throughout phylogenesis, that assist in protein folding, prevent aggregation, and ensure cellular homeostasis under stressful conditions. In H. pylori, HSPs contribute to survival in the stomach’s acidic environment and oxidative stress. Furthermore, they aid in the bacterium’s ability to adhere to gastric epithelial cells, modulate the host immune response, and form biofilms, all contributing to chronic infection and pathogenicity. The role of microbial HSPs in antibiotic resistance has also emerged as a critical area of research, as these proteins help stabilize efflux pumps, protect essential proteins targeted by antibiotics, and promote biofilm formation, thereby reducing the efficacy of antimicrobial treatments. Among bacterial HSPs, GroEL and DnaK are probably the major proteins that control most of the H. pylori’s functioning. Indeed, both proteins possess remarkable acid resistance, high substrate affinity, and dual roles in protein homeostasis and host interaction. These features make them critical for H. pylori’s adaptation, persistence, and pathogenicity in the gastric niche. In addition, recent findings have also highlighted the involvement of HSPs in the crosstalk between H. pylori and gastric epithelial cells mediated by the release of bacterial outer membrane vesicles and host-derived exosomes, both of these extracellular vesicles being part of the muco-microbiotic layer of the stomach and influencing cellular signalling and immune modulation. Considering their critical role in the survival and persistence of bacteria, microbial HSPs also represent potential therapeutic targets. Strategies aimed at inhibiting microbial HSP function, combined with conventional antibiotics or developing vaccines targeting microbial HSPs, could provide new avenues for the treatment of H. pylori infections and combat antibiotic resistance. This review explores the multifaceted roles of microbial HSPs in the pathogenesis of H. pylori, highlighting their contributions to bacterial adhesion, immune evasion, stress response, and antibiotic resistance. Full article

Autoimmune gastritis (AIG) has a strong correlation with gastric neuroendocrine tumors (NETs) and gastric cancer, making its timely and accurate diagnosis crucial for tumor prevention. The endoscopic manifestations of AIG differ from those of gastritis caused by Helicobacter pylori (H. pylori) infection in terms of the affected gastric anatomical regions and the pathological characteristics observed in biopsy samples. Therefore, when diagnosing AIG based on endoscopic images, it is essential not only to distinguish between normal and atrophic gastric mucosa but also to accurately identify the anatomical region in which the atrophic mucosa is located. In this study, we propose a patient-based multitask gastroscopy image classification network that analyzes all images obtained during the endoscopic procedure. First, we employ the Scale-Invariant Feature Transform (SIFT) algorithm for image registration, generating an image similarity matrix. Next, we use a hierarchical clustering algorithm to group images based on this matrix. Finally, we apply the RepLKNet model, which utilizes large-kernel convolution, to each image group to perform two tasks: anatomical region classification and lesion recognition. Our method achieves an accuracy of 93.4 ± 0.5% (95% CI) and a precision of 92.6 ± 0.4% (95% CI) in the anatomical region classification task, which categorizes images into the fundus, body, and antrum. Additionally, it attains an accuracy of 90.2 ± 1.0% (95% CI) and a precision of 90.5 ± 0.8% (95% CI) in the lesion recognition task, which identifies the presence of gastric mucosal atrophic lesions in gastroscopy images. These results demonstrate that the proposed multitask patient-based gastroscopy image analysis method holds significant practical value for advancing computer-aided diagnosis systems for atrophic gastritis and enhancing the diagnostic accuracy and efficiency of AIG. Full article

Helicobacter pylori and Candida spp. are widespread microorganisms found in the human gastrointestinal tract, often coexisting in the same ecological niche. H. pylori, a Gram-negative bacterium, is a well-known pathogen responsible for gastritis, peptic ulcers, and gastric cancer. In contrast, Candida fungi, often detected in food, particularly Candida albicans, are generally considered commensal organisms, but can become opportunistic pathogens under certain conditions. Recent studies suggest a possible link between these microorganisms, highlighting a new survival strategy of H. pylori, that is, its ability to internalize in Candida vacuoles. This phenomenon, confirmed by various microscopic and molecular techniques, may provide H. pylori with protection against adverse environmental conditions, especially clinically important antibiotic therapy. The basic premise of this theory is the ability of H. pylori to penetrate vacuoles in fungal cells, which then become a reservoir of infection, allowing the infection to recur. Understanding the interaction between H. pylori and Candida may offer new insights into the pathogenesis of gastrointestinal diseases and may lead to the development of treatments targeting both organisms simultaneously. The purpose of this article is to review the literature, considering the first observations on this problem in the literature and the current state of knowledge, and to suggest a direction for further research. Full article