Determination of Helicobacter pyloriVirulence by Simple Gene Analysis of the cagPathogenicity Island

ABSTRACT Nucleic acid amplification was performed for five loci in thecag pathogenicity island (PAI) of Helicobacter pylori (comprising cagA, the cagApromoter region, cagE, cagT, and the left end of cagII [LEC]), and gastric inflammation in patients was evaluated. Of 204 H. pylori isolates from Japanese patients (53 with peptic ulcer, 55 with gastric cancer, and 96 with chronic gastritis), 197 (96.6%) were positive for all five loci. Two isolates (1%) were negative for all five loci, and five isolates (2.4%) were positive for only cagA and LEC. These latter seven isolates were all from patients with mild chronic gastritis. Neutrophil infiltration in gastric mucosa was significantly milder in patients infected with partially or totally deleted-PAI strains than in those with intact-PAI strains. The cagE gene was a more accurate marker of an intact cag PAI than thecagA gene, and cagE seemed to be more useful in discriminating between H. pylori strains causing different rates of disease progression.

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Helicobacter pyloriAnti-CagA Antibodies: Prevalence in Symptomatic and Asymptomatic Subjects in Turkey

Canadian Journal of Gastroenterology ◽

10.1155/2002/589087 ◽

2002 ◽

Vol 16 (8) ◽

pp. 527-532 ◽

Cited By ~ 13

Author(s):

M Fatih Abasiyanik ◽

Ersan Sander ◽

Barik A Salih

Keyword(s):

Gastric Cancer ◽

Duodenal Ulcer ◽

Helicobacter Pylori ◽

Peptic Ulcer ◽

Chronic Gastritis ◽

Molecular Weights ◽

Cancer Antigens ◽

Gastroduodenal Disease ◽

H Pylori ◽

Asymptomatic Subjects

BACKGROUND: Several reports have shown the prevalence of anti-CagA antibodies to be associated with the development of peptic ulcer diseases, while others have indicated that there is no such association.AIM: To examine the prevalence of antibodies to CagA and otherHelicobacter pyloriantigens in symptomatic and asymptomatic subjects in Turkey.SUBJECTS AND METHODS: Sixty-six symptomatic subjects, 16 to 74 years of age, were examined forH pyloriby biopsy-based tests and ELISA. One hundred nineteen asymptomatic subjects, 20 to 65 years of age, were also tested serologically for the presence ofH pylori. Samples from both groups that were found to be positive forH pyloriby ELISA were then tested by immunoblotting.RESULTS: Fifty-four (82%) symptomatic subjects and 76 (64%) asymptomatic subjects were found to beH pylori-positive by ELISA. Samples from 30 symptomatic subjects who were found to beH pylori-positive by ELISA were analyzed by immunoblotting. Antibodies to CagA (116 kDa) antigen were detected in immunoblots of 11 of 14 (79%) with chronic gastritis, 12 of 13 (92%) with duodenal ulcer and three of three (100%) with gastric cancer. Antigens of the following molecular weights were also detected in these 30 subjects: 89 kDa (VacA) in 21 (70%), 37 kDa in 21 (70%), 35 kDa in 19 (63%), 30 kDa in 27 (90%) and 19.5 kDa in 19 (63%). Immunoblots of 40 ELISA-positive asymptomatic subjects showed that 33 (83%) had antibodies to CagA antigen, 26 (65%) to VacA antigen, 30 (75%) to a 37 kDa antigen, 30 (75%) to a 35 kDa antigen, 39 (98%) to a 30 kDa antigen and 36 (90%) to a 19.5 kDa antigen.CONCLUSIONS: Antibodies to CagA antigen were prevalent in both groups, regardless of the presence of gastroduodenal disease.

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Implications of Helicobacter pylori infection for stomach cancer prevention

Cadernos de Saúde Pública ◽

10.1590/s0102-311x1997000500003 ◽

1997 ◽

Vol 13 (suppl 1) ◽

pp. S15-S25 ◽

Cited By ~ 6

Author(s):

Karen J. Goodman

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Peptic Ulcer ◽

Stomach Cancer ◽

Chronic Gastritis ◽

Host Susceptibility ◽

Natural Immunity ◽

Limited Effectiveness ◽

H Pylori ◽

Incident Cases

Accumulating evidence has implicated Helicobacter pylori, an established cause of chronic gastritis and peptic ulcer, in the etiology of gastric cancer. Control of this infection would reduce the occurrence of chronic gastritis and peptic ulcer and might substantially lower the risk of stomach cancer as well. The public health impact of this infectious agent warrants efforts to identify preventive measures. This paper reviews the evidence linking H. pylori infection to gastric cancer and evaluates the potential for control in high-risk populations. Current obstacles to H. pylori control are discussed, including the link to poor socioeconomic conditions, difficulty in identifying incident cases, lack of natural immunity to reinfection, limited effectiveness of antibiotic therapy in high-prevalence populations, and incomplete knowledge regarding the reservoir of infection, mode of transmission, host susceptibility factors, and the potential for developing an effective vaccine. Worthwhile avenues of research include studies designed to identify modifiable risk factors for acquisition of the infection, modifiable host factors that may increase resistance to chronic infection, more effective antibiotic therapies, and effective vaccines.

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Induction and prevention of gastric cancer with combined Helicobacter pylori and capsaicin administration and DFMO treatment, respectively

10.21203/rs.2.21633/v1 ◽

2020 ◽

Author(s):

Faisal Aziz ◽

Mingxia Xin ◽

Yunfeng Gao ◽

Josh Monts ◽

Kjersten Monson ◽

...

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Mouse Models ◽

Chronic Gastritis ◽

Molecular Mechanisms ◽

Gastric Carcinogenesis ◽

Lifestyle Changes ◽

Host Susceptibility ◽

Anti Inflammatory ◽

H Pylori

Abstract Background: Gastric cancer risk evolves over time due to environmental, dietary, and lifestyle changes including Helicobacter pylori (H. pylori) infection and consumption of hot peppers (i.e. capsaicin). H. pylori infection promotes gastric mucosal injury in the early phase of capsaicin exposure. In addition, capsaicin consumption is reported to suppress immune function and increase host susceptibility to microbial infection. This relationship suggests a need to investigate the mechanism of how both H. pylori infection and capsaicin contribute to gastric inflammation and lead to gastric cancer. No previous experimental animal models have been developed to study this dual association. Here we developed a series of mouse models that progress from chronic gastritis to gastric cancer. C57-Balb/c mice were infected with the H. pylori (SS1) strain and then fed capsaicin (0.05% or 0.2g/kg/day) or not. Consequently, we investigated the association between H. pylori infection and capsaicin consumption during the initiation of gastric inflammation and the later development of gastric cancer. Tumor size and phenotype were analyzed to determine the molecular mechanism driving the shift from gastritis to stomach cancer. Gastric carcinogenesis was also prevented in these models using the ornithine decarboxylase inhibitor DFMO (2-difluoromethylornithine). Results: This study provides evidence showing that a combination of H. pylori infection and capsaicin consumption leads to gastric carcinogenesis. The transition from chronic gastritis to gastric cancer is mediated through interleukin-6 (IL-6) stimulation with an incidence rate of 50%. However, this progression can be prevented by treating with anti-inflammatory agents. In particular, we used DFMO to prevent gastric tumorigenesis by reducing inflammation and promoting recovery of disease-free stasis. The anti-inflammatory role of DFMO highlights the injurious effect of inflammation in gastric cancer development and the need to reduce gastric inflammation for cancer prevention. Conclusions: Overall, these mouse models provide reliable systems for analyzing the molecular mechanisms and synergistic effects of H. pylori and capsaicin on human cancer etiology. Accordingly, preventive measures like reduced capsaicin consumption, H. pylori clearance, and DFMO treatment can lessen gastric cancer incidence. Lastly, anti-inflammatory agents like DFMO can play important roles in prevention of inflammation-associated gastric cancer.

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Virulence genes of Helicobacter pylori in the Dominican Republic

Journal of Medical Microbiology ◽

10.1099/jmm.0.075275-0 ◽

2014 ◽

Vol 63 (9) ◽

pp. 1189-1196 ◽

Cited By ~ 18

Author(s):

Seiji Shiota ◽

Modesto Cruz ◽

José A. Jiménez Abreu ◽

Takahiro Mitsui ◽

Hideo Terao ◽

...

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Peptic Ulcer ◽

Dominican Republic ◽

Infection Rate ◽

Rapid Urease Test ◽

Test Culture ◽

Urease Test ◽

The Status ◽

H Pylori

Although the incidence of gastric cancer in the Dominican Republic is not high, the disease remains a significant health problem. We first conducted a detailed analysis of Helicobacter pylori status in the Dominican Republic. In total, 158 patients (103 females and 55 males; mean age 47.1±16.2 years) were recruited. The status of H. pylori infection was determined based on four tests: rapid urease test, culture test, histological test and immunohistochemistry. The status of cagA and vacA genotypes in H. pylori was examined using PCR and gene sequencing. The overall prevalence of H. pylori infection was 58.9 %. No relationship was found between the H. pylori infection rate and the age range of 17–91 years. Even in the youngest group (patients aged <29 years), the H. pylori infection rate was 62.5 %. Peptic ulcer was found in 23 patients and gastric cancer was found in one patient. The H. pylori infection rate in patients with peptic ulcer was significantly higher than that in patients with gastritis (82.6 versus 54.5 %, P<0.01). The cagA-positive/vacA s1m1 genotype was the most prevalent (43/64, 67.2 %). Compared with H. pylori-negative patients, H. pylori-positive patients showed more severe gastritis. Furthermore, the presence of cagA was related to the presence of more severe gastritis. All CagA-positive strains had Western-type CagA. In conclusion, we found that H. pylori infection is a risk factor for peptic ulcer in the Dominican Republic. Patients with cagA-positive H. pylori could be at higher risk for severe inflammation and atrophy.

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Helicobacter Pylori Associated Antral Gastritis in Peptic Ulcer Disease Patients and Normal Healthy Population of Kashmir, India

Diagnostic and Therapeutic Endoscopy ◽

10.1155/dte.4.135 ◽

1998 ◽

Vol 4 (3) ◽

pp. 135-139 ◽

Cited By ~ 2

Author(s):

Gh. Jeelani Romshoo ◽

G. M. Malik ◽

M. Youssuf Bhat ◽

Ab. Rashid rather ◽

Javaid Ahmad Basu ◽

...

Keyword(s):

Helicobacter Pylori ◽

Peptic Ulcer ◽

Gastric Ulcer ◽

Peptic Ulcer Disease ◽

Healthy Volunteers ◽

Chronic Gastritis ◽

Healthy Population ◽

Ulcer Disease ◽

Antral Gastritis ◽

H Pylori

Aim: To study the association of Helicobacter pylori infection with chronic antral gastritis in peptic ulcer disease patients and healthy population of Kashmir.Methods: 50 peptic ulcer patients (duodenal ulcer = 46, gastric ulcer = 2 and combined duodenal and gastric ulcer = 2) and 30 asymptomatic healthy volunteers were included in this study. Peptic ulcer was diagnosed on endoscopic examination. 4–6 punch biopsies were taken from gastric antrum in all the individuals and in case of gastric ulcer an additional biopsy was taken from the edge of the ulcer to exclude its malignant nature. Helicobacter pylori (H. pylori) organism was diagnosed using three different test methods, viz. Histology (using Giemsa Stain), Microbiology (Gram Stain) and Biochemistry (using one minute Endoscopy Room Test). Histological diagnosis of H. pylori was taken as the “gold standard” for the presence of H. pylori organism. Histological diagnosis of gastritis was made using Hematoxylin and Eosin Stain and the gastritis was classified as active chronic gastritis and superficial chronic gastritis.Results: Out of 30 peptic ulcer disease patients with associated antral gastritis, 27 (90%) were positive for H. pylori on histological examination (13 superficial chronic gastritis and 14 active chronic gastritis) whereas out of 8 healthy volunteers with histological evidence of chronic antral gastritis, H. pylori was observed in 7 individuals (87.50%) (4 active chronic gastritis and 3 superficial chronic gastritis).Conclusion: A highly significant association between H. pylori infection with chronic antral gastritis both in peptic ulcer disease patients and healthy volunteers of Kashmir was found in this study. Association between H. pylori infection and chronic gastritis was 90% in peptic ulcer group and 87.50% in healthy population (P<0.005).

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Functional Analysis of the cag Pathogenicity Island in Helicobacter pylori Isolates from Patients with Gastritis, Peptic Ulcer, and Gastric Cancer

Infection and Immunity ◽

10.1128/iai.72.2.1043-1056.2004 ◽

2004 ◽

Vol 72 (2) ◽

pp. 1043-1056 ◽

Cited By ~ 87

Author(s):

Steffen Backert ◽

Tobias Schwarz ◽

Stephan Miehlke ◽

Christian Kirsch ◽

Christian Sommer ◽

...

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Peptic Ulcer ◽

Pathogenicity Island ◽

Epidemiological Studies ◽

Disease Development ◽

Gastric Diseases ◽

H Pylori ◽

Gastric Cancer Patients

ABSTRACT Helicobacter pylori is the causative agent of a variety of gastric diseases, but the clinical relevance of bacterial virulence factors is still controversial. Virulent strains carrying the cag pathogenicity island (cagPAI) are thought to be key players in disease development. Here, we have compared cagPAI-dependent in vitro responses in H. pylori isolates obtained from 75 patients with gastritis, peptic ulcer, and gastric cancer (n = 25 in each group). AGS gastric epithelial cells were infected with each strain and assayed for (i) CagA expression, (ii) translocation and tyrosine phosphorylation of CagA, (iii) c-Src inactivation, (iv) cortactin dephosphorylation, (v) induction of actin cytoskeletal rearrangements associated with cell elongation, (vi) induction of cellular motility, and (vii) secretion of interleukin-8. Interestingly, we found high but similar prevalences of all of these cagPAI-dependent host cell responses (ranging from 56 to 80%) among the various groups of patients. This study revealed CagA proteins with unique features, CagA subspecies of various sizes, and new functional properties for the phenotypic outcomes. We further showed that induction of AGS cell motility and elongation are two independent processes. Our data corroborate epidemiological studies, which indicate a significant association of cagPAI presence and functionality with histopathological findings in gastritis, peptic ulcer, and gastric cancer patients, thus emphasizing the importance of the cagPAI for the pathogenicity of H. pylori. Nevertheless, we found no significant association of the specific H. pylori-induced responses with any particular patient group. This may indicate that the determination of disease development is highly complex and involves multiple bacterial and/or host factors.

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

Pathogens ◽

10.3390/pathogens8020065 ◽

2019 ◽

Vol 8 (2) ◽

pp. 65

Author(s):

Mariateresa Casarotto ◽

Chiara Pratesi ◽

Ettore Bidoli ◽

Stefania Maiero ◽

Raffaella Magris ◽

...

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Precancerous Lesions ◽

Neutrophil Infiltration ◽

Host Bacterium ◽

Gastric Cancer Risk ◽

Increased Risk ◽

Cytotoxin Associated Gene A ◽

Sydney System ◽

H Pylori

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

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Precancerous Gastric Lesions with Helicobacter pylori vacA+/babA2+/oipA+ Genotype Increase the Risk of Gastric Cancer

BioMed Research International ◽

10.1155/2020/7243029 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Theeraya Simawaranon Bartpho ◽

Wareeporn Wattanawongdon ◽

Taweesak Tongtawee ◽

Chatchanok Paoin ◽

Kokiet Kangwantas ◽

...

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Clinical Outcomes ◽

Chronic Gastritis ◽

Virulence Genes ◽

Gastric Lesions ◽

Precancerous Gastric Lesions ◽

Increased Risk ◽

H Pylori ◽

Gastric Cancer Patients

Objective. The clinical outcomes of gastric diseases such as chronic gastritis, peptic ulcer, and gastric cancer have been attributed to the interplay of virulence factors of Helicobacter pylori (H. pylori), host genetic susceptibility, and host immune responses. This study investigated the presence of cagA, vacA, iceA2, babA2, and oipA genes and their association with clinical outcomes. Methods. Chronic gastritis, atrophic gastritis, and intestinal metaplasia specimens were obtained from patients who underwent endoscopy and surgical resection between January 2017 and December 2018; specimens from gastric cancer patients treated between January 2014 and December 2018 were also added. H. pylori infection and virulence genes (cagA, vacA, iceA2, babA2, and oipA) were determined using real-time PCR. The association between H. pylori genotypes and clinical outcomes were evaluated using multivariate regression model analysis. The overall survival of gastric cancer patients was compared between genotype combinations. Results. H. pylori was positive in 166 patients with chronic gastritis, precancerous gastric lesions, and gastric cancer. The genes vacA, babA2, and oipA were most prevalent in chronic gastritis (73%), precancerous gastric lesions (62%), and gastric cancer (91%), respectively. The vacA, babA2, and oipA genes were associated with increased risk of gastric cancer (OR = 1.23; 95% CI = 1.13–3.32; P=0.033, OR = 2.64; 95% CI = 1.44–4.82, P=0.024, and OR = 2.79; 95% CI = 1.58–5.41; P=0.031, respectively). Interestingly, H. pylori vacA+/babA2+/oipA+ genotype infection was associated with increased risk of gastric cancer (OR = 3.85, 95% CI = 1.67–5.77, P=0.014). Conclusion. In this present study, we reported on the virulence genes of H. pylori infection to reveal their association with increased risk of chronic gastritis, precancerous gastric lesions, and gastric cancer. Precancerous gastric lesions with H. pylori vacA+/babA2+/oipA+ genotype increased the risk of gastric cancer.

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Recent Advances inHelicobacter pyloriInfection in Children: From the Petri Dish to the Playgound

Canadian Journal of Gastroenterology ◽

10.1155/2003/809530 ◽

2003 ◽

Vol 17 (7) ◽

pp. 448-454 ◽

Cited By ~ 4

Author(s):

Peng-Yuan Zheng ◽

Nicola L Jones

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Peptic Ulcer ◽

Petri Dish ◽

Host Factors ◽

Causative Role ◽

Ulcer Disease ◽

Recent Advances ◽

H Pylori ◽

Development Of Gastric Cancer

Helicobacter pyloriinfection is acquired in childhood, plays a causative role in chronic gastritis and peptic ulcer disease, and is associated with the development of gastric cancer. The present review focuses on recent advances in the scientific knowledge ofH pyloriinfection in children, including clinical sequelae, diagnosis and treatment. In addition, recent insights regarding both bacterial and host factors that mediate human diseases associated withH pyloriinfection are discussed.

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The Human Gastric Pathogen Helicobacter pylori and Its Association with Gastric Cancer and Ulcer Disease

Ulcers ◽

10.1155/2011/340157 ◽

2011 ◽

Vol 2011 ◽

pp. 1-23 ◽

Cited By ~ 58

Author(s):

Bianca Bauer ◽

Thomas F. Meyer

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Peptic Ulcer ◽

Peptic Ulcer Disease ◽

Strain Differences ◽

Protective Effects ◽

Ulcer Disease ◽

Prophylactic Measures ◽

H Pylori

With the momentous discovery in the 1980's that a bacterium, Helicobacter pylori, can cause peptic ulcer disease and gastric cancer, antibiotic therapies and prophylactic measures have been successful, only in part, in reducing the global burden of these diseases. To date, ~700,000 deaths worldwide are still attributable annually to gastric cancer alone. Here, we review H. pylori's contribution to the epidemiology and histopathology of both gastric cancer and peptic ulcer disease. Furthermore, we examine the host-pathogen relationship and H. pylori biology in context of these diseases, focusing on strain differences, virulence factors (CagA and VacA), immune activation and the challenges posed by resistance to existing therapies. We consider also the important role of host-genetic variants, for example, in inflammatory response genes, in determining infection outcome and the role of H. pylori in other pathologies—some accepted, for example, MALT lymphoma, and others more controversial, for example, idiopathic thrombocytic purpura. More recently, intriguing suggestions that H. pylori has protective effects in GERD and autoimmune diseases, such as asthma, have gained momentum. Therefore, we consider the basis for these suggestions and discuss the potential impact for future therapeutic rationales.

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