An inverse relationship between CagA+ strains of Helicobacter pylori infection and risk of erosive GERD

International Nuclear Information System (INIS)

Somi, Mohammad H.; Fattahi, E.; Fouladi, Rohollah F.; Karimi, M.; Bonyadi, R.; Baballou, Z.

2008-01-01

The aim of this study is investigating the association of Helicobacter pylori (H. pylori) infection and its cytogenetic-associated gene A (cag A) strain with reflux esophagitis. In a case-control setting (May 2005-2006), patients with reflux esophagitis (case group) were compared with age and gender matched people suffering from symptoms of gastroesophageal reflux disease with normal upper gastrointestinal endoscopic findings (control group) in Imam Khomeini Hospital, Tabriz, Iran. The rates of H. pylori and its cagA positive infections were separately compared between the 2 groups and the subgroups with different severity of reflux esophagitis. Ninety-two and 93 patients were enrolled in the case and control groups. The rate of H.pylori infection was significantly lower in case group (81.5%versus 87.10%, p=0.29, odd ratio 0.654, 95% confidence interval [CI] 0.293 to 1.495). The CagA positive infections were found significantly more frequent in the control group (59.1% versus 40.2%, p=0.01, odd ratio 0.465, 95% CI 0.258 to 0.836). There was no significant difference between the severity subgroups of the disease for H. pylori (p=0.30) or cagA positive infection rates (p=0.40). The cagA positive strains might have a protective effect against reflux esophagitis. (author)

Analysis of cagA in Helicobacter pylori strains from Colombian populations with contrasting gastric cancer risk reveals a biomarker for disease severity

Science.gov (United States)

Loh, John T.; Shaffer, Carrie L.; Piazuelo, M. Blanca; Bravo, Luis E.; McClain, Mark S.; Correa, Pelayo; Cover, Timothy L.

2011-01-01

BACKGROUND Helicobacter pylori infection is a risk factor for the development of gastric cancer, and the bacterial oncoprotein CagA contributes to gastric carcinogenesis. METHODS We analyzed H. pylori isolates from persons in Colombia and observed that there was marked variation among strains in levels of CagA expression. To elucidate the basis for this variation, we analyzed sequences upstream from the CagA translational initiation site in each strain. RESULTS A DNA motif (AATAAGATA) upstream of the translational initiation site of CagA was associated with high levels of CagA expression. Experimental studies showed that this motif was necessary but not sufficient for high-level CagA expression. H. pylori strains from a region of Colombia with high gastric cancer rates expressed higher levels of CagA than did strains from a region with lower gastric cancer rates, and Colombian strains of European phylogeographic origin expressed higher levels of CagA than did strains of African origin. Histopathological analysis of gastric biopsy specimens revealed that strains expressing high levels of CagA or containing the AATAAGATA motif were associated with more advanced precancerous lesions than those found in persons infected with strains expressing low levels of CagA or lacking the AATAAGATA motif. CONCLUSIONS CagA expression varies greatly among H. pylori strains. The DNA motif identified in this study is associated with high levels of CagA expression, and may be a useful biomarker to predict gastric cancer risk. IMPACT These findings help to explain why some persons infected with cagA-positive H. pylori develop gastric cancer and others do not. PMID:21859954

Helicobacter pylori cagA+ Is Associated with Milder Duodenal Histological Changes in Chilean Celiac Patients

Directory of Open Access Journals (Sweden)

Yalda Lucero

2017-08-01

Full Text Available HIGHLIGHTSWhat is already known about this subject?Celiac disease (CD has a high clinical and histological diversity and the mechanisms underlying this phenomenon remain elusive.H. pylori is a bacterium that chronically infect gastric and duodenal mucosa activating both a Th1/Th17 and T-reg pathways.The role of H. pylori (and the effect of their virulence factors in CD have not yet completely elucidated.What are the new findings?cagA+ H. pylori strains are associated to milder histological damage in infected CD patients.In active-CD patients the presence of cagA+ H. pylori is associated to an increase in T-reg markers, contrasting with a downregulation in cagA+ infected potential-CD individuals.How might it impact on clinical practice in the foreseeable future?The identification of microbiological factors that could modulate inflammation and clinical expression of CD may be used in the future as preventive strategies or as supplementary treatment in patients that cannot achieve complete remission, contributing to the better care of these patients.Background: Mechanisms underlying the high clinical and histological diversity of celiac disease (CD remain elusive. Helicobacter pylori (Hp chronically infects gastric and duodenal mucosa and has been associated with protection against some immune-mediated conditions, but its role (specifically of cagA+ strains in CD is unclear.Objective: To assess the relationship between gastric Hp infection (cagA+ strains and duodenal histological damage in patients with CD.Design: Case-control study including patients with active-CD, potential-CD and non-celiac individuals. Clinical presentation, HLA genotype, Hp/cagA gene detection in gastric mucosa, duodenal histology, Foxp3 positive cells and TGF-β expression in duodenal lamina propria were analyzed.Results: We recruited 116 patients, 29 active-CD, 37 potential-CD, and 50 non-CD controls. Hp detection was similar in the three groups (~30–40%, but cagA

Systematic analysis of phosphotyrosine antibodies recognizing single phosphorylated EPIYA-motifs in CagA of Western-type Helicobacter pylori strains.

Directory of Open Access Journals (Sweden)

Judith Lind

Full Text Available The clinical outcome of Helicobacter pylori infections is determined by multiple host-pathogen interactions that may develop to chronic gastritis, and sometimes peptic ulcers or gastric cancer. Highly virulent strains encode a type IV secretion system (T4SS that delivers the effector protein CagA into gastric epithelial cells. Translocated CagA undergoes tyrosine phosphorylation at EPIYA-sequence motifs, called A, B and C in Western-type strains, by members of the oncogenic Src and Abl host kinases. Phosphorylated EPIYA-motifs mediate interactions of CagA with host signaling factors--in particular various SH2-domain containing human proteins--thereby hijacking multiple downstream signaling cascades. Observations of tyrosine-phosphorylated CagA are mainly based on the use of commercial phosphotyrosine antibodies, which originally were selected to detect phosphotyrosines in mammalian proteins. Systematic studies of phosphorylated EPIYA-motif detection by the different antibodies would be very useful, but are not yet available. To address this issue, we synthesized phospho- and non-phosphopeptides representing each predominant Western CagA EPIYA-motif, and determined the recognition patterns of seven different phosphotyrosine antibodies in Western blots, and also performed infection studies with diverse representative Western H. pylori strains. Our results show that a total of 9-11 amino acids containing the phosphorylated EPIYA-motifs are necessary and sufficient for specific detection by these antibodies, but revealed great variability in sequence recognition. Three of the antibodies recognized phosphorylated EPIYA-motifs A, B and C similarly well; whereas preferential binding to phosphorylated motif A and motifs A and C was found with two and one antibodies, respectively, and the seventh anti-phosphotyrosine antibody did not recognize any phosphorylated EPIYA-motif. Controls showed that none of the antibodies recognized the corresponding non

Structural biology studies of CagA from Helicobacter pylori and histone chaperone CIA/ASF1

International Nuclear Information System (INIS)

Senda, Toshiya

2015-01-01

Crystal structures of proteins and their complexes have become critical information for molecular-based life science. Biochemical and biological analysis based on tertiary structural information is a powerful tool to unveil complex molecular processes in the cell. Here, we present two examples of the structure-based life science study, structural biology studies of CagA, an effector protein from Helicobacter pylori, and histone chaperone CIA/ASF1, which is involved in transcription initiation. (author)

High diversity of vacA and cagA Helicobacter pylori genotypes in patients with and without gastric cancer.

Directory of Open Access Journals (Sweden)

Yolanda López-Vidal

Full Text Available BACKGROUND: Helicobacter pylori is associated with chronic gastritis, peptic ulcers, and gastric cancer. The aim of this study was to assess the topographical distribution of H. pylori in the stomach as well as the vacA and cagA genotypes in patients with and without gastric cancer. METHODOLOGY/PRINCIPAL FINDINGS: Three gastric biopsies, from predetermined regions, were evaluated in 16 patients with gastric cancer and 14 patients with dyspeptic symptoms. From cancer patients, additional biopsy specimens were obtained from tumor centers and margins; among these samples, the presence of H. pylori vacA and cagA genotypes was evaluated. Positive H. pylori was 38% and 26% in biopsies obtained from the gastric cancer and non-cancer groups, respectively (p = 0.008, and 36% in tumor sites. In cancer patients, we found a preferential distribution of H. pylori in the fundus and corpus, whereas, in the non-cancer group, the distribution was uniform (p = 0.003. A majority of the biopsies were simultaneously cagA gene-positive and -negative. The fundus and corpus demonstrated a higher positivity rate for the cagA gene in the non-cancer group (p = 0.036. A mixture of cagA gene sizes was also significantly more frequent in this group (p = 0.003. Ninety-two percent of all the subjects showed more than one vacA gene genotype; s1b and m1 vacA genotypes were predominantly found in the gastric cancer group. The highest vacA-genotype signal-sequence diversity was found in the corpus and 5 cm from tumor margins. CONCLUSION/SIGNIFICANCE: High H. pylori colonization diversity, along with the cagA gene, was found predominantly in the fundus and corpus of patients with gastric cancer. The genotype diversity observed across systematic whole-organ and tumor sampling was remarkable. We find that there is insufficient evidence to support the association of one isolate with a specific disease, due to the multistrain nature of H. pylori infection shown in this work.

Evolution of cagA oncogene of Helicobacter pylori through recombination.

Directory of Open Access Journals (Sweden)

Yoshikazu Furuta

Full Text Available Helicobacter pylori is a gastric pathogen that infects half the human population and causes gastritis, ulcers, and cancer. The cagA gene product is a major virulence factor associated with gastric cancer. It is injected into epithelial cells, undergoes phosphorylation by host cell kinases, and perturbs host signaling pathways. CagA is known for its geographical, structural, and functional diversity in the C-terminal half, where an EPIYA host-interacting motif is repeated. The Western version of CagA carries the EPIYA segment types A, B, and C, while the East Asian CagA carries types A, B, and D and shows higher virulence. Many structural variants such as duplications and deletions are reported. In this study, we gained insight into the relationships of CagA variants through various modes of recombination, by analyzing all known cagA variants at the DNA sequence level with the single nucleotide resolution. Processes that occurred were: (i homologous recombination between DNA sequences for CagA multimerization (CM sequence; (ii recombination between DNA sequences for the EPIYA motif; and (iii recombination between short similar DNA sequences. The left half of the EPIYA-D segment characteristic of East Asian CagA was derived from Western type EPIYA, with Amerind type EPIYA as the intermediate, through rearrangements of specific sequences within the gene. Adaptive amino acid changes were detected in the variable region as well as in the conserved region at sites to which no specific function has yet been assigned. Each showed a unique evolutionary distribution. These results clarify recombination-mediated routes of cagA evolution and provide a solid basis for a deeper understanding of its function in pathogenesis.

The distribution of cagA and dupA genes in Helicobacter pylori strains in Kurdistan region, northern Iraq.

Science.gov (United States)

Salih, Azad M; Goreal, Amer; Hussein, Nawfal R; Abdullah, Shahla M; Hawrami, Khidir; Assafi, Mahde

2013-01-01

Helicobacter pylori is a Gram negative bacteria that causes peptic ulceration and gastric adenocarcinoma. H pylori virulence factors, such as cagA and dupA, are important to study in populations as they contribute to disease risk. This study aimed to look at the distribution of the cagA and dupA genes in H pylori strains isolated from patients suffering from gastroduodenal diseases in Kurdistan region, Iraq. A cross-sectional study conducted between June 2011 and January 2012. Biopsies were collected from the Endoscopy Department in Duhok and Sulaimania hospitals, Kurdistan region, northern Iraq. Upper gastrointestinal (GI) endoscopy examination was performed and 4 gastric biopsies (2 from the antrum and 2 from the corpus) were obtained from 204 patients. H pylori positivity was examined by CLO test; then the association between disease status and virulence factors was assessed by polymerase chain reaction. 154 (75%) of our samples were found to be H pylori + by CLO test. Endoscopic diagnoses for those who were positive were as follows: peptic ulcer disease (PUD) including duodenal ulcer, 45; gastric ulcer, 23; and no ulcer (NPUD), 86. The overall prevalence rates of cagA and dupA were 72.7% and 18.8%, respectively. While a significant association between cagA and PUD was observed (P. ≤.017; OR=0.4; CI=0.18–0.85), no relationship between dupA and PUD could be seen. These data suggested that the presence of cagA may be a predictor of clinical outcome in Kurdistan region, northern Iraq.

Prevalence and Correlation with Clinical Diseases of Helicobacter pylori cagA and vacA Genotype among Gastric Patients from Northeast China

Directory of Open Access Journals (Sweden)

Faisal Aziz

2014-01-01

Full Text Available Helicobacter pylori vacA and cagA genes have significant genetic heterogenicity, resulting in different clinical outcomes. Northeast part of China has reported high prevalence of H. pylori infections and gastric cancer. Hence, we investigated the H. pylori cagA and vacA genotypes with clinical outcomes in Northeast China. Gastric tissue samples (n=169, chronic gastritis (GIs, gastric ulcer (GU, and gastric cancer (GC were analysed for 16S rRNA ureA, cagA, and cagA genotypes by PCR. A total of 141 (84% cases were found positive for H. pylori by 16S rRNA and ureA. GC showed high H. pylori infection (93% compared with GIs (72% and GU (84%. The vacAs1am1 was highly found in GC (40% and GU (36%, vacAs1am2 in GIs (33%, vacAs1bm1 (14% and vacAs1bm2 (8% in GU cases, and s2m1 in normal cases (33%, while vacAs1cm1 showed low frequency in GIs (2% and GU (3% and GC showed negative result. The East-Asian cagA strain was highly observed in GC (43%, as compared to GIs (41% and GU (20%. The East-Asian cagA/vacAs1am1 was significantly higher in GC (23% than in GU (22% and GIs (145 patients. The East-Asian type cagA with vacAs1a and vacAm1 is the most predominant genotype in H. pylori strains of Northeast China.

Expression of cagA, virB/D Complex and/or vacA Genes in Helicobacter pylori Strains Originating from Patients with Gastric Diseases.

Directory of Open Access Journals (Sweden)

Andrzej Szkaradkiewicz

Full Text Available In order to better understand pathogenicity of Helicobacter pylori, particularly in the context of its carcinogenic activity, we analysed expression of virulence genes: cagA, virB/D complex (virB4, virB7, virB8, virB9, virB10, virB11, virD4 and vacA in strains of the pathogen originating from persons with gastric diseases. The studies were conducted on 42 strains of H. pylori isolated from patients with histological diagnosis of non-atrophic gastritis-NAG (group 1, including subgroup 1 containing cagA+ isolates and subgroup 2 containing cagA- strains, multifocal atrophic gastritis-MAG (group 2 and gastric adenocarcinoma-GC (group 3. Expression of H. pylori genes was studied using microarray technology. In group 1, in all strains of H. pylori cagA+ (subgroup 1 high expression of the gene as well as of virB/D was disclosed, accompanied by moderate expression of vacA. In strains of subgroup 2 a moderate expression of vacA was detected. All strains in groups 2 and 3 carried cagA gene but they differed in its expression: a high expression was detected in isolates of group 2 and its hyperexpression in strains of group 3 (hypervirulent strains. In both groups high expression of virB/D and vacA was disclosed. Our results indicate that chronic active gastritis may be induced by both cagA+ strains of H. pylori, manifesting high expression of virB/D complex but moderate activity of vacA, and cagA- strains with moderate expression of vacA gene. On the other hand, in progression of gastric pathology and carcinogenesis linked to H. pylori a significant role was played by hypervirulent strains, manifesting a very high expression of cagA and high activity of virB/D and vacA genes.

Prevalence of cagA and vacA among Helicobacter pylori-infected patients in Iran: a systematic review and meta-analysis.

Science.gov (United States)

Sayehmiri, Fatemeh; Kiani, Faezeh; Sayehmiri, Kourosh; Soroush, Setareh; Asadollahi, Khairollah; Alikhani, Mohammad Yousef; Delpisheh, Ali; Emaneini, Mohammad; Bogdanović, Lidija; Varzi, Ali Mohammad; Zarrilli, Raffaele; Taherikalani, Morovat

2015-07-30

The varieties of infections caused by Helicobacter pylori may be due to differences in bacterial genotypes and virulence factors as well as environmental and host-related factors. This study aimed to investigate the prevalence of cagA and vacA genes among H. pylori-infected patients in Iran and analyze their relevance to the disease status between two clinical groups via a meta-analysis method. Different databases including PubMed, ISI, Scopus, SID, Magiran, Science Direct, and Medlib were investigated, and 23 relevant articles from the period between 2001 and 2012 were finally analyzed. The relevant data obtained from these papers were analyzed by a random-effects model. Data were analyzed using R software and STATA. The prevalence of cagA and vacA genes among H. pylori-infected patients was 70% (95% CI, 64-75) and 41% (95% CI, 24.3-57.7), respectively. The prevalence of duodenal ulcers, peptic ulcers, and gastritis among cagA+ individuals was 53% (95% CI, 20-86), 65% (95% CI, 34-97), and 71% (95% CI, 59-84), respectively. Odds ratio (OR) between cagA-positive compared with cagA-negative patients showed a 1.89 (95% CI, 1.38-2.57) risk of ulcers. In conclusion, the frequency of cagA gene among H. pylori strains is elevated in Iran and it seems to be more frequently associated with gastritis. Therefore, any information about cagA and vacA prevalence among different H. pylori-infected clinical groups in the country can help public health authorities to plan preventive policies to reduce the prevalence of diseases associated with H. pylori infection.

VacA, CagA, IceA and OipA Genotype Status of Helicobacter pylori ...

African Journals Online (AJOL)

Purpose: To investigate the state of vacA, cagA, oipA and iceA genotypes of H. pylori isolated from gastric biopsy samples of dogs. Methods: A total of 240 gastric biopsy samples were taken from 240 dogs using gastric endoscope. All the samples were cultured and H. pylori-positive samples were analyzed for the presence ...

Prevalence of Helicobacter pylori cagA, babA2, and dupA genotypes andcorrelation with clinical outcome in Malaysian patients with dyspepsia

OpenAIRE

OSMAN, HUSSEIN ALI; HASAN, HABSAH; SUPPIAN, RAPEAH; HASSAN, SYED; ANDEE, DZULKARNAEN ZAKARIA; MAJID, NOORIZAN ABDUL; ZILFALIL, BIN ALWI

2015-01-01

Background/aim: The severity of disease outcome in dyspepsia has been attributed to Helicobacter pylori virulence genes. The aim of this study was to determine the distribution of H. pylori virulence genes (cagA, babA2, and dupA) and to determine whether or not there arises a significant correlation with clinical dyspepsia outcomes. Materials and methods: H. pylori genotypes cagA, babA2, and dupA were identified by polymerase chain reactions from gastric biopsy samples in 105 H. pylori-posit...

Prevalence of Helicobacter pylori vacA Genotypes and cagA Gene in Dental Plaque of Asymptomatic Mexican Children

Science.gov (United States)

Mendoza-Cantú, Alejandra; Urbina-Ríos, Cynthia Sofía; García-Martínez, Martha Elena; Torre-Martínez, Hilda H. H.

2017-01-01

The variability in Helicobacter pylori vacA and cagA genes has been related to the progression of the gastrointestinal disease; also the presence of H. pylori in the oral cavity has been associated with periodontal disease in adults, but, in children without dyspeptic symptoms, little is known about this. We evaluated the prevalence of H. pylori and the presence of vacA/cagA genotypes in the oral cavity of Mexican children without dyspeptic symptoms. The gingival status was measured, and dental plaque samples (n = 100) were taken. 38% of children were positive for H. pylori 16S rRNA gene by qPCR. A significant association between H. pylori oral infection and gingival status was observed (P < 0.001). In 34.6% (9/26) of mild gingivitis cases, s1m2 genotype was found, while s1m1 was typed in 50% (3/6) of moderate gingivitis. The cagA prevalence among H. pylori-positive children was 80.8% (21/26), 83.3% (5/6), and 16.7% (1/6) of cases of mild gingivitis, moderate gingivitis, and nongingivitis, respectively (P < 0.001). The s1m1/cagA+ combinational genotype was the most detected in children with gingivitis. Our results suggest that the prevalence of H. pylori and detection of vacA/cagA genotypes-associated gastrointestinal disease in the oral cavity could be related to the progression of gingivitis in asymptomatic children. PMID:29226140

Prevalence of Helicobacter pylori vacA Genotypes and cagA Gene in Dental Plaque of Asymptomatic Mexican Children

Directory of Open Access Journals (Sweden)

Alejandra Mendoza-Cantú

2017-01-01

Full Text Available The variability in Helicobacter pylori vacA and cagA genes has been related to the progression of the gastrointestinal disease; also the presence of H. pylori in the oral cavity has been associated with periodontal disease in adults, but, in children without dyspeptic symptoms, little is known about this. We evaluated the prevalence of H. pylori and the presence of vacA/cagA genotypes in the oral cavity of Mexican children without dyspeptic symptoms. The gingival status was measured, and dental plaque samples (n=100 were taken. 38% of children were positive for H. pylori 16S rRNA gene by qPCR. A significant association between H. pylori oral infection and gingival status was observed (P<0.001. In 34.6% (9/26 of mild gingivitis cases, s1m2 genotype was found, while s1m1 was typed in 50% (3/6 of moderate gingivitis. The cagA prevalence among H. pylori-positive children was 80.8% (21/26, 83.3% (5/6, and 16.7% (1/6 of cases of mild gingivitis, moderate gingivitis, and nongingivitis, respectively (P<0.001. The s1m1/cagA+ combinational genotype was the most detected in children with gingivitis. Our results suggest that the prevalence of H. pylori and detection of vacA/cagA genotypes-associated gastrointestinal disease in the oral cavity could be related to the progression of gingivitis in asymptomatic children.

Importance of Helicobacter pylori cagA and vacA status for the efficacy of antibiotic treatment

NARCIS (Netherlands)

L.-J. van Doorn (Leen-Jan); P.M. Schneeberger (Peter); N. Nouhan (N.); A.P. Plaisier (Anton); W.G.V. Quint (Wim); W.A. de Boer (Wink)

2000-01-01

textabstractBackground - Virulence factors of Helicobacter pylori are associated with peptic ulcer disease and may be also associated with the efficacy of treatment. Aims - To determine the relation between the vacA and the cagA status of H pylori, clinical disease, and treatment outcome. Patients -

Prevalence of Helicobacter pylori cagA, babA2, and dupA genotypes and correlation with clinical outcome in Malaysian patients with dyspepsia.

Science.gov (United States)

Osman, Hussein Ali; Hasan, Habsah; Suppian, Rapeah; Hassan, Syed; Andee, Dzulkarnaen Zakaria; Abdul Majid, Noorizan; Zilfalil, Bin-alwi

2015-01-01

The severity of disease outcome in dyspepsia has been attributed to Helicobacter pylori virulence genes. The aim of this study was to determine the distribution of H. pylori virulence genes (cagA, babA2, and dupA) and to determine whether or not there arises a significant correlation with clinical dyspepsia outcomes. H. pylori genotypes cagA, babA2, and dupA were identified by polymerase chain reactions from gastric biopsy samples in 105 H. pylori-positive patients. The positive rates for cagA, babA2, and dupA genes in H. pylori dyspeptic patients were 69.5%, 41.0%, and 22.9%, respectivel cagA was more prevalent in Indians (39.7%), babA2 was more prevalent in Malays (39.5%), and dupA detection occurred more frequently in both Indians and Malays and at the same rate (37.5%). The Chinese inhabitants had the lowest prevalence of the three genes. Nonulcer disease patients had a significantly higher distribution of cagA (76.7%), babA2 (74.4%), and dupA (75.0%). There was no apparent association between these virulence genes and the clinical outcomes. The lower prevalence of these genes and variations among different ethnicities implies that the strains are geographically and ethnically dependent. None of the virulence genes were knowingly beneficial in predicting the clinical outcome of H. pylori infection in our subjects.

Helicobacter pylori VacA, acting through receptor protein tyrosine phosphatase ?, is crucial for CagA phosphorylation in human duodenum carcinoma cell line AZ-521

OpenAIRE

Nakano, Masayuki; Yahiro, Kinnosuke; Yamasaki, Eiki; Kurazono, Hisao; Akada, Junko; Yamaoka, Yoshio; Niidome, Takuro; Hatakeyama, Masanori; Suzuki, Hidekazu; Yamamoto, Taro; Moss, Joel; Isomoto, Hajime; Hirayama, Toshiya

2016-01-01

ABSTRACT Helicobacter pylori, a major cause of gastroduodenal diseases, produces vacuolating cytotoxin (VacA) and cytotoxin-associated gene A (CagA), which seem to be involved in virulence. VacA exhibits pleiotropic actions in gastroduodenal disorders via its specific receptors. Recently, we found that VacA induced the phosphorylation of cellular Src kinase (Src) at Tyr418 in AZ-521 cells. Silencing of receptor protein tyrosine phosphatase (RPTP)?, a VacA receptor, reduced VacA-induced Src ph...

Variation in the number of EPIYA-C repeats in CagA protein from Colombian Helicobacter pylori strains and its ability to induce hummingbird phenotype in gastric epithelial cells Variación en el número de repeticiones EPIYA-C en la proteína CagA de aislamientos colombianos de Helicobacter pylori y su capacidad para inducir fenotipo colibrí en células epiteliales gástricas

Directory of Open Access Journals (Sweden)

María Mercedes Bravo

2010-08-01

Full Text Available Introduction. Studies using Western Helicobacter pylori strains have shown that a risk factor for gastric cancer is the number of EPIYA-C motifs in the cytotoxin-associated A protein. CagA is delivered into epithelial cells, where it becomes tyrosine phosphorylated in their EPIYA repeats and induces cytoskeleton rearrangements.
Objectives. The objective of this study was to evaluate H. pylori cagA positive strains isolated from Colombian patients with gastroduodenal diseases for the number of EPIYA-C repeats in cagA and their ability to induce cytoskeleton rearrangements in epithelial cells.
Materials and methods. We analyzed the 3' EPIYA repeats region of cagA by PCR in 93 H. pylori cagA positive strains from 49 patients with gastritis, 17 with gastric cancer, and 24 with duodenal ulcer. AGS cells exposed to the various H. pylori isolates were evaluated for rearrangements in their cytoskeleton.
Results. Strains with one EPIYA-C were the most frequent in gastritis and duodenal ulcer patients. Strains with three EPIYA-C were mainly found in gastric cancer. We found a significantly higher risk of gastric cancer for individuals infected with strains harboring three EPIYA-C motifs (OR=12.4, CI95%: 2.32-66.3. Strains from gastric cancer showed significantly higher percentages of induction of cytoskeleton rearrangements in comparison with those from gastritis (p Mann-Whitney<0.005.
Conclusions. H. pylori strains with three EPIYA-C repeats can confer an increased risk of cancer to infected individuals.Introducción. En los aislamientos de Helicobacter pylori del hemisferio occidental, se ha observado que el número de repeticiones EPIYA-C en la proteína CagA es un factor de riesgo para cáncer gástrico. La proteína CagA es introducida en la célula epitelial y, posteriormente, es fosforilada en las tirosinas presentes en los motivos EPIYA e induce rearreglos en el citoesqueleto.
Objetivos. Nuestro propósito fue evaluar el n

Soroprevalência de anticorpos contra o antígeno CagA do Helicobacter pylori em pacientes com úlcera gástrica na região Norte do Brasil Seroprevalence of antibodies against the CagA antigen the Helicobacter pylori in patients with gastric ulcer in the North region of Brazil

Directory of Open Access Journals (Sweden)

Luisa Caricio Martins

2002-08-01

Full Text Available O Helicobacter pylori é um agente patogênico largamente distribuído no mundo, estando envolvido no desenvolvimento de várias doenças gastrointestinais. Atualmente a infecção pela cepa virulenta (CagA+ do H. pylori é considerado um dos principais fatores etiológicos para o desenvolvimento de ulcerações gástricas. Baseado nessa informação, investigamos a soroprevalência das cepas virulentas entre os pacientes com úlcera gástrica da nossa região, utilizando testes sorológicos para detecção de anticorpos contra o H. pylori e a proteína CagA. Sendo observado que 82% (45/55 dos pacientes estavam infectados pela cepa virulenta, entre esses 89% (40/45 apresentaram grau de inflamação aumentado na mucosa gástrica, com denso infiltrado de leucócitos no tecido, o que provavelmente favoreceu a formação das ulcerações gástricas.Helicobacter pylori is a pathogenic agent with a worldwide distribution and is involved in the development of many gastrointestinal diseases. Nowadays infection with the virulent strain CagA+ of H. pylori is considered one of the main etiological factors in the development of gastric ulcer. Based on this information, we investigated the seroprevalence of virulent strains among patients with gastric ulcer from one region, using serologic tests to detect antibodies against H. pylori and CagA protein. Infection by the virulent strain was found in 82% (40/55 of the patients, and among these, 89% (40/45 presented an increased degree of inflammation in the gastric mucosa, with a dense infiltration of leukocytes in the tissue, which probably favored the formation of gastric ulcer. We concluded that the presence of the virulent strain is related to the development of an increased inflammation in the gastric mucosa.

VacA and cagA genotypes of Helicobacter pylori isolated from raw meat in Isfahan province, Iran.

Science.gov (United States)

Gilani, Ali; Razavilar, Vadood; Rokni, Nordahr; Rahimi, Ebrahim

2017-01-01

Foods with animal origins play a substantial role in the transmission of Helicobacter pylori . The present investigation was carried out to study the vacA and cagA genotypes status of H. pylori isolated from various types of meat samples. Two hundred and twenty meat samples were collected and cultured. H. pylori -positive strains were analyzed for the presence of vacA and cagA genotypes. Eleven out of 220 (5.00%) samples were positive for H. pylori . Findings were confirmed by nested PCR. Prevalence of H. pylori in the meat samples of slaughterhouses and butcheries were 72.20% and 27.70%, respectively. The most commonly detected genotypes in the meat samples of slaughterhouses and butcheries were vacA m1a (66.66%) and vacA s1a (37.50%), respectively. The S1am1a was the most commonly detected genotype. Meat sampled from butcheries had the higher prevalence of H. pylori and its genotypes than those of slaughterhouses ( p meat samples could be the potential sources of virulent strains of H. pylori . Application of sanitary measures in the storage, transportation and sale of meat is essential for reducing the levels of H. pylori cross contamination.

Association among H. pylori virulence markers dupA, cagA and vacA in Brazilian patients.

Science.gov (United States)

Pereira, Weendelly Nayara; Ferraz, Mariane Avante; Zabaglia, Luanna Munhoz; de Labio, Roger William; Orcini, Wilson Aparecido; Bianchi Ximenez, João Paulo; Neto, Agostinho Caleman; Payão, Spencer Luiz Marques; Rasmussen, Lucas Trevizani

2014-01-23

Only a few Helicobacter pylori-infected individuals develop severe gastric diseases and virulence factors of H. pylori appear to be involved in such clinical outcomes. Duodenal ulcer promoting gene A (dupA) is a novel virulence factor of Helicobacter pylori that is associated with duodenal ulcer development and reduced risk for gastric carcinoma in some populations. The aims of the present study were to determine the presence of dupA gene and evaluate the association among dupA and other virulence factors including cagA and vacA in Brazilian patients. Gastric biopsies were obtained from 205 dyspeptic patients (100 children and 105 adults). DNA was extracted and analyzed for the presence of H. pylori and its virulence factors using the polymerase chain reaction method. Patients with gastritis tested positive for H. pylori more frequently. The dupA gene was detected in 41.5% of them (85/205); cagA gene was found in 98 isolates (47.8%) and vacA genotype s1/m1 in 50.2%, s1/m2 in 8.3%, s2/m2 in 36.6%, s2/m1 in 0.5% and s1/s2/m1/m2 in 4.4%. We also verified a significant association between cagA and dupA genes [p = 0.0003, relative risk (RR) 1.73 and confidence interval [CI] = 1.3-2.3]. The genotypes s1/m1 were also associated with dupA gene (p = 0.0001, RR: 1.72 and CI: 1.3-2.2). The same associations were found when analyzing pediatric and adult groups of patients individually. Ours results suggest that dupA is highly frequent in Brazilian patients and is associated with cagA gene and vacA s1/m1 genotype, and it may be considered an important virulence factor in the development of gastric diseases in adults or children.

Helicobacter pylori Outer Membrane Protein-Related Pathogenesis

Directory of Open Access Journals (Sweden)

Yuichi Matsuo

2017-03-01

Full Text Available Helicobacter pylori colonizes the human stomach and induces inflammation, and in some cases persistent infection can result in gastric cancer. Attachment to the gastric mucosa is the first step in establishing bacterial colonization, and outer membrane proteins (OMPs play a pivotal role in binding to human cells. Some OMP interaction molecules are known in H. pylori, and their associated host cell responses have been gradually clarified. Many studies have demonstrated that OMPs are essential to CagA translocation into gastric cells via the Type IV secretion system of H. pylori. This review summarizes the mechanisms through which H. pylori utilizes OMPs to colonize the human stomach and how OMPs cooperate with the Type IV secretion system.

Anti-CagA IgG Antibody is Independent from Helicobacter pylori vacA and cagA Genotypes

Directory of Open Access Journals (Sweden)

Hashem Fakhre Yaseri

2015-12-01

Full Text Available Background: Helicobacter pylori strains have two classical virulence genes, the cytotoxinassociated A (cagA gene and the vacuolating cytotoxin A (vacA gene, which are located in thecag pathogenicity island (cagPAI. Serum immunoglobulin G (IgG antibodies to H. pylori,especially, the CagA antigen may be a reliable marker for selection of dyspeptic patients for upperendoscopy.Methods: Serum sample of 129 dyspeptic patients with positive H. pylori, were tested for serumIgG Anti-CagA antibody by ELISA. The presence of the cagA and vacA genotypes weredetermined using polymerase chain reaction (PCR on biopsy samples taken via endoscopy.Results: Positive serum IgG anti-CagA antibodies in patients with cagA+/vacA+ and cagA+/vacA- genotypes were 22/23 (95.6% and 18/19 (94.7%, respectively. In addition, serum IgG anti-CagAantibodies in patients with cagA-/vacA+ and cagA-/vacA- genotypes were 22/47 (46.8% and 33/40(82.5%, respectively.Conclusions: It can be concluded that the serum IgG anti-CagA antibody alone could selectpatients with dyspepsia following upper endoscopy. The assessment of vacuolating cytotoxinactivity of H. Pylori is, therefore, not required, even when vacA gene is positive. This hypothesisneeds to be studied in a large number of patients with dyspepsia.

Helicobacter pylori vacA and cagA genotypes in patients from northeastern Brazil with upper gastrointestinal diseases

Directory of Open Access Journals (Sweden)

Meyssa Quezado de Figueiredo Cavalcante

2012-06-01

Full Text Available Helicobacter pylori causes chronic gastric inflammation and significantly increases the risk of duodenal and gastric ulcer disease and distal gastric carcinoma. In this study, we evaluated the Helicobacter pylori vacA and cagA genotypes in patients from a Brazilian region where there is a high prevalence of gastric cancer. Polymerase chain reaction (PCR was used to investigate vacA mosaicism and cagA status in the gastric mucosa of 134 H. pylori-positive patients, including 76 with gastritis: 28 with peptic ulcer disease and 30 with gastric cancer. The s1m1 variant was the predominant vacA genotype observed, whereas the s1 allele was more frequently observed in patients with more severe diseases associated with H. pylori infection [p = 0.03, odds ratio (OR = 5.72, 95% confidence interval (CI = 1.15-38.60]. Furthermore, all of the s1 alleles were s1b. Mixed vacA m1/m2 strains were found more frequently in patients with gastric cancer and a cagA-positive status was significantly associated with gastric cancer (p = 0.016, OR = 10.36, 95% CI = 1.35-217.31. Patients with gastric cancer (21/21, 100%, p = 0.006 or peptic ulcers (20/21, 95%, p = 0.02 were more frequently colonised by more virulent H. pylori strains compared to gastritis patients (41/61, 67.2%. In conclusion, in the northeastern of Brazil, which is one of the regions with the highest prevalence of gastric cancer in the country, infection with the most virulent H. pylori strains, carrying the cagA gene and s1m1 vacA alleles, predominates and is correlated with more severe H. pylori-associated diseases.

Distinct repeat motifs at the C-terminal region of CagA of Helicobacter pylori strains isolated from diseased patients and asymptomatic individuals in West Bengal, India

Directory of Open Access Journals (Sweden)

Chattopadhyay Santanu

2012-05-01

Full Text Available Abstract Background Infection with Helicobacter pylori strains that express CagA is associated with gastritis, peptic ulcer disease, and gastric adenocarcinoma. The biological function of CagA depends on tyrosine phosphorylation by a cellular kinase. The phosphate acceptor tyrosine moiety is present within the EPIYA motif at the C-terminal region of the protein. This region is highly polymorphic due to variations in the number of EPIYA motifs and the polymorphism found in spacer regions among EPIYA motifs. The aim of this study was to analyze the polymorphism at the C-terminal end of CagA and to evaluate its association with the clinical status of the host in West Bengal, India. Results Seventy-seven H. pylori strains isolated from patients with various clinical statuses were used to characterize the C-ternimal polymorphic region of CagA. Our analysis showed that there is no correlation between the previously described CagA types and various disease outcomes in Indian context. Further analyses of different CagA structures revealed that the repeat units in the spacer sequences within the EPIYA motifs are actually more discrete than the previously proposed models of CagA variants. Conclusion Our analyses suggest that EPIYA motifs as well as the spacer sequence units are present as distinct insertions and deletions, which possibly have arisen from extensive recombination events. Moreover, we have identified several new CagA types, which could not be typed by the existing systems and therefore, we have proposed a new typing system. We hypothesize that a cagA gene encoding higher number EPIYA motifs may perhaps have arisen from cagA genes that encode lesser EPIYA motifs by acquisition of DNA segments through recombination events.

Helicobacter pylori cagA and iceA genotypes status and risk of peptic ulcer in Saudi patients

International Nuclear Information System (INIS)

Momenah, Aiman M.; Tayeb, Mohammad T.

2007-01-01

Objective was to determine the prevalence of cagA+ and iceA genotypes among Helicobacter pylori (H. pylori) isolates from a group of Saudi patients with gastric complaints, and to find out any significant correlation between these strains and severe gastric clinical outcomes such as peptic ulcer and gastric cancer in Saudi population. A total of 1104 gastric biopsies from 368 patients who presented with symptoms suggestive of chronic gastritis, peptic ulcer disease, or gastric carcinoma were taken from the main hospitals in the Western region of Saudi Arabia from July 2004 to July 2005. We cultured the samples for H. pylori and a polymerase chain reaction was carried out to check for the presence or absence of cagA gene and the status of iceA genotypes. Among the 368 suspected patients to be infected with H. pylori by means of clinical features and endoscopic findings; 103 (28%) were positive using culture technique. The relation of the presence of cagA and the development of cases to gastritis and ulcer was statistically significant (p=0.0001). Furthermore, this study revealed that 100% of ulcer cases were infected with iceA1 with a statistically significant correlation (p=0.0001), while 94.6% of gastritis and 90.9% of normal were infected with iceA2 (p=0.0001). Moreover cagA+/iceA1 combined genotypes was statistically correlated with peptic ulcer (100%) but not cagA-/iceA1 (0%; p=0.0001).Certain H. pylori genotypes were more virulent than others. Multiple clinical implications based on these finding might be studied further.(author)

Association between cagA, vacAi, and dupA genes of Helicobacter pylori and gastroduodenal pathologies in Chilean patients.

Science.gov (United States)

Paredes-Osses, Esteban; Sáez, Katia; Sanhueza, Enrique; Hebel, Sonja; González, Carlos; Briceño, Carlos; García Cancino, Apolinaria

2017-09-01

In addition to the already known cagA gene, novel genetic markers have been associated with Helicobacter pylori (H. pylori) virulence: the dupA and vacAi genes. These genes might play an important role as specific markers to determine the clinical outcome of the disease, especially the vacAi gene, which has been expected to be a good marker of severe pathologies like gastric adenocarcinoma. In the present study, the association of cagA, dupA, and vacAi genes with gastroduodenal pathologies in Chilean patients was studied. One hundred and thirty-two patients positive for H. pylori were divided into two groups-non-severe and severe gastric pathologies-and investigated for the presence of cagA, dupA, and vacAi H. pylori virulence genes by PCR. The cagA gene was detected in 20/132 patients (15.2%), the vacAi1 gene was detected in 54/132 patients (40.9%), the vacAi2 gene was detected in 26/132 patients (19.7%), and the dupA gene was detected in 50/132 (37.9%) patients. Logistic regression model analysis showed that the vacAi1 isoform gene in the infected strains and the severity of the diseases outcome were highly associated, causing severe gastric damage that may lead to gastric cancer (p dupA gene was associated significantly with non-severe clinical outcome (p = 0.0032; OR = 0.25; 95% CI 0.09-0.65). In addition, dupA gene exerts protection against severe gastric pathologies induced by vacAi1 by delaying the outcome of the disease by approximately 20 years.

Infecção por Helicobacter pylori e câncer gástrico: freqüência de cepas patogênicas cagA e vacA em pacientes com câncer gástrico Helicobacter pylori and gastric cancer: distribution of cagA and vacA genotypes in patients with gastric carcinoma

Directory of Open Access Journals (Sweden)

Cristiane Melissa Thomazini

2006-02-01

Full Text Available INTRODUÇÃO: Apesar da alta freqüência de infecção por Helicobacter pylori na população, somente uma minoria de indivíduos desenvolve câncer gástrico. É provável que a colonização da mucosa por cepas patogênicas, levando a maior agressão e inflamação da mucosa seja um dos elos da cadeia de eventos da oncogênese gástrica. OBJETIVOS: Investigar a freqüência de cepas patogênicas cagA e vacA do H. pylori em pacientes com câncer gástrico. MATERIAL E MÉTODOS: Foram estudados retrospectivamente 42 pacientes com câncer gástrico. A infecção por H. pylori foi avaliada por exame histológico e pelo PCR para identificação dos genótipos cagA e vacA em amostras de material fixado em formalina e incluído em parafina. RESULTADOS: A análise histológica permitiu a visualização direta do H. pylori em 85,7% dos casos, e o método de PCR para o gene urease C demonstrou a presença de DNA da bactéria em 95% dos casos. O gene cagA foi detectado em amostras de 23 pacientes (54,7% com câncer gástrico. O alelo s1 do gene vacA foi identificado em amostras de 24 pacientes (57,1% e o alelo m1, em amostras de 26 pacientes (61,9%. Os alelos s1 e m1 foram identificados simultaneamente em 24 pacientes (57,1%. O alelo s2 foi identificado em amostras de quatro pacientes (9,5%, e o alelo m2, em amostras de três pacientes (7,1%. A freqüência de infecção pelo Helicobacter pylori foi similar em ambos os tipos histológicos de câncer gástrico (intestinal e difuso. CONCLUSÕES: Os resultados confirmam a relevância dos genótipos patogênicos cagA e vacA do H. pylori para lesões orgânicas significativas tais como o câncer gástrico, sugerindo a participação dessa bactéria na cadeia de eventos da oncogênese gástrica.BACKGROUND: The rates of Helicobacter pylori infection are very high worldwide, but only a minority of infected patients develop gastric carcinoma. This might be related, among several factors, to the colonization of

Higher frequency of cagA EPIYA-C Phosphorylation Sites in H. pylori strains from first-degree relatives of gastric cancer patients

Directory of Open Access Journals (Sweden)

Queiroz Dulciene MM

2012-08-01

Full Text Available Abstract Background To evaluate the prevalence of more virulent H. pylori genotypes in relatives of gastric cancer patients and in patients without family histories of gastric cancer. Methods We evaluated prospectively the prevalence of the infection by more virulent H. pylori strains in 60 relatives of gastric cancer patients comparing the results with those obtained from 49 patients without family histories of gastric cancer. H. pylori status was determined by the urease test, histology and presence of H. pylori ureA. The cytotoxin associated gene (cagA, the cagA-EPIYA and vacuolating cytotoxin gene (vacA were typed by PCR and the cagA EPIYA typing was confirmed by sequencing. Results The gastric cancer relatives were significant and independently more frequently colonized by H. pylori strains with higher numbers of CagA-EPIYA-C segments (OR = 4.23, 95%CI = 1.53–11.69 and with the most virulent s1m1 vacA genotype (OR = 2.80, 95%CI = 1.04–7.51. Higher numbers of EPIYA-C segments were associated with increased gastric corpus inflammation, foveolar hyperplasia and atrophy. Infection by s1m1 vacA genotype was associated with increased antral and corpus gastritis. Conclusions We demonstrated that relatives of gastric cancer patients are more frequently colonized by the most virulent H. pylori cagA and vacA genotypes, which may contribute to increase the risk of gastric cancer.

Role of the Helicobacter pylori virulence factors vacuolating cytotoxin, CagA, and urease in a mouse model of disease.

Science.gov (United States)

Ghiara, P; Marchetti, M; Blaser, M J; Tummuru, M K; Cover, T L; Segal, E D; Tompkins, L S; Rappuoli, R

1995-10-01

The pathogenic role of Helicobacter pylori virulence factors has been studied with a mouse model of gastric disease. BALB/c mice were treated orally with different amounts of sonic extracts of cytotoxic H. pylori strains (NCTC 11637, 60190, 84-183, and 87A300 [CagA+/Tox+]). The pathological effects on histological sections of gastric mucosae were assessed and were compared with the effects of treatments with extracts from noncytotoxic strains (G21 and G50 [CagA-/Tox-]) and from strains that express either CagA alone (D931 [CagA+/Tox-]) or the cytotoxin alone (G104 [CagA-/Tox+]). The treatment with extracts from cytotoxic strains induced various epithelial lesions (vacuolation, erosions, and ulcerations), recruitment of inflammatory cells in the lamina propria, and a marked reduction of the mucin layer. Extracts of noncytotoxic strains induced mucin depletion but no other significant pathology. Crude extracts of strain D931, expressing CagA alone, caused only mild infiltration of inflammatory cells, whereas extracts of strain G104, expressing cytotoxin alone, induced extensive epithelial damage but little inflammatory reaction. Loss of the mucin layer was not associated with a cytotoxic phenotype, since this loss was observed in mice treated with crude extracts of all strains. The pathogenic roles of CagA, cytotoxin, and urease were further assessed by using extracts of mutant strains of H. pylori defective in the expression of each of these virulence factors. The results obtained suggest that (i) urease activity does not play a significant role in inducing the observed gastric damage, (ii) cytotoxin has an important role in the induction of gastric epithelial cell lesions but not in eliciting inflammation, and (iii) other components present in strains which carry the cagA gene, but distinct from CagA itself, are involved in eliciting the inflammatory response.

cagA Status and Eradication Treatment Outcome of Anti-Helicobacter pylori Triple Therapies in Patients with Nonulcer Dyspepsia

Science.gov (United States)

Broutet, Nathalie; Marais, Armelle; Lamouliatte, Hervé; de Mascarel, Antoine; Samoyeau, Roland; Salamon, Roger; Mégraud, Francis

2001-01-01

The differences in eradication rates reported in clinical trials aiming to cure Helicobacter pylori infection cannot be entirely explained by the type of regimen, bacterial resistance, or lack of compliance. Using data from a clinical trial, a logistic regression model was constructed to determine whether cagA status, assessed by PCR, affects the outcome of eradication. Resistance to clarithromycin (10% of the strains) predicted failure perfectly. In the model (n = 156), a cagA-lacking strain (odds ratio [OR] = 2.2; 95% confidence interval [CI], (1.1 to 4.7), tobacco smoking OR = 3.1; 95% CI, 1.3 to 7.0), and a double dose of proton pump inhibitor in the treatment regimen (OR = 0.3; 95% CI, 0.2 to 0.7) were associated with the treatment outcome. The exact role of cagA in the outcome of H. pylori eradication therapy has not been explored. However, the type of histological lesions which it causes in the gastric mucosa may be implicated. Regardless of the mechanism involved, cagA status is a good predictive marker of eradication outcome. PMID:11283049

The Middle Fragment of Helicobacter pylori CagA Induces Actin Rearrangement and Triggers Its Own Uptake into Gastric Epithelial Cells

Directory of Open Access Journals (Sweden)

Abolghasem Tohidpour

2017-07-01

Full Text Available Cytotoxin-associated gene product A (CagA is a major virulence factor secreted by Helicobacter pylori. CagA activity in the gastric epithelium is associated with higher risk of gastric cancer development. Bacterial type IV secretion system (T4SS-mediated translocation of CagA into the cytosol of human epithelial cells occurs via a poorly understood mechanism that requires CagA interaction with the host membrane lipid phosphatidylserine (PS and host cell receptor integrin α5β1. Here we have characterized the isolated recombinant middle fragment of CagA (CagA-M that contains the positively-charged PS-binding region (aa 613–636 and a putative β1 integrin binding site, but lacks the EPIYA region, secretion signal peptide and the CagA multimerization motif. We show that CagA-M, when immobilized on latex beads, is capable of binding to, and triggering its own uptake into, gastric epithelial cells in the absence of infection with cagA-positive H. pylori. Using site-directed mutagenesis, fluorescent and electron microscopy, and highly-specific inhibitors, we demonstrate that the cell-binding and endocytosis-like internalization of CagA-M are dependent on (1 binding to PS; (2 β1 integrin activity; and (3 actin dynamics. Interaction of CagA-M with the host cells is accompanied by the development of long filopodia-like protrusions (macrospikes. This novel morphology is different from the hummingbird phenotype induced by the translocation of full-length CagA. The determinants within CagA-M and within the host that are important for endocytosis-like internalization into host cells are very similar to those observed for T4SS-mediated internalization of full-length CagA, suggesting that the latter may involve an endocytic pathway.

VacA and cagA genotypes status and antimicrobial resistance properties of Helicobacter pylori strains isolated from meat products in Isfahan province, Iran.

Science.gov (United States)

Gilani, A; Razavilar, V; Rokni, N; Rahimi, E

2017-01-01

Although Helicobacter pylori has a significant impact on the occurrence of severe clinical syndromes, its exact ways of transmission and origin have not been identified. According to the results of some previously published articles, foods with animal origins play a substantial role in the transmission of H. pylori to humans. The present investigation was carried out to study the vacuolating cytotoxin A ( vacA ) and cytotoxin associated gene A ( cagA ) genotypes status and antibiotic resistance properties of H. pylori strains recovered from minced-meat and hamburger samples. A total of 150 meat product samples were collected from supermarkets. All samples were cultured and the susceptive colonies were then subjected to nested-PCR, PCR-based genotyping and disk diffusion methods. 11 out of 150 samples (7.33%) were positive for H. pylori . All the isolates were further identified using the nested-PCR assay. Prevalence of H. pylori in hamburger and minced-meat samples was 1.42% and 12.5%, respectively. S1a , m1a and cagA were the most commonly detected genotypes. The most commonly detected combined genotypes in the H. pylori strains of minced-meat were s1am1a (10%), s1am1b (10%) and s2m1a (10%). Helicobacter pylori strains of meat products harbored the highest levels of resistance against ampicillin (90.90%), erythromycin (72.72%), amoxicillin (72.72%), trimethoprim (63.63%), tetracycline (63.63%), and clarithromycin (63.63%). Hamburger and minced-meat samples may be the sources of virulent and resistant strains of H. pylori . Meat products are possible sources of resistant and virulent strains of H. pylori similar to those vacA and cagA genotypes. Using healthy raw materials and observation of personal hygiene can reduce the risk of H. pylori in meat products.

Helicobacter pylori cagA and vacA genotypes in Cuban and Venezuelan populations

Directory of Open Access Journals (Sweden)

Diana Ortiz-Princz

2010-05-01

Full Text Available The aim of this study was to determine the presence of Helicobacter pylori cytotoxin-associated gene (cagA/vacuolating cytotoxin gene (vacA among patients with chronic gastritis in Cuba and Venezuela. Gastric antrum biopsies were taken for culture, DNA extraction and PCR analysis. Amplification of vacA and cagA segments was performed using two regions of cagA: 349 bp were amplified with the F1/B1 primers and the remaining 335 bp were amplified with the B7629/B7628 primers. The VA1-F/VA1-R set of primers was used to amplify the 259-bp (s1 or 286-bp (s2 product and the VAG-R/VAG-F set of primers was used to amplify the 567-bp (m1 or 642-bp (m2 regions of vacA. cagA was detected in 87% of the antral samples from Cuban patients and 80.3% of those from Venezuelan patients. All possible combinations of vacA regions were found, with the exception of s2/m1. The predominant combination found in both countries was s1/m1. The percentage of cagA+ strains was increased by the use of a second set of primers and a greater number of strains was amplified with the B7629/B7628 primers in the Cuban patients (p = 0.0001. There was no significant difference between the presence of the allelic variants of vacA and cagA in both populations. The predominant genotype was cagA+/s1m1 in both countries. The results support the necessary investigation of isolates circulating among the human population in each region.

Role of Helicobacter pylori cagA EPIYA motif and vacA genotypes for the development of gastrointestinal diseases in Southeast Asian countries: a meta-analysis

Directory of Open Access Journals (Sweden)

Sahara Shu

2012-09-01

Full Text Available Abstract Background Infection with cagA-positive, cagA EPIYA motif ABD type, and vacA s1, m1, and i1 genotype strains of Helicobacter pylori is associated with an exacerbated inflammatory response and increased risk of gastroduodenal diseases. However, it is unclear whether the prevalence and virulence factor genotypes found in Southeast Asia are similar to those in Western countries. Here, we examined the cagA status and prevalence of cagA EPIYA motifs and vacA genotypes among H. pylori strains found in Southeast Asia and examined their association with gastroduodenal disease. Methods To determine the cagA status, cagA EPIYA motifs, and vacA genotypes of H. pylori, we conducted meta-analyses of 13 previous reports for 1,281 H. pylori strains detected from several Southeast Asian countries. Results The respective frequencies of cagA-positive and vacA s1, m1, and i1 genotypes among examined subjects were 93% (1,056/1,133, 98% (1,010/1,033, 58% (581/1,009, and 96% (248/259, respectively. Stratification showed significant variation in the frequencies of cagA status and vacA genotypes among countries and the individual races residing within each respective country. The frequency of the vacA m-region genotype in patients infected with East Asian-type strains differed significantly between the northern and southern areas of Vietnam (p vacA m1 type or cagA-positive strains was associated with an increased risk of peptic ulcer disease (odds ratio: 1.46, 95%CI: 1.01-2.12, p = 0.046 and 2.83, 1.50-5.34, p = 0.001, respectively in the examined Southeast Asian populations. Conclusions Both Western- and East Asian-type strains of H. pylori are found in Southeast Asia and are predominantly cagA-positive and vacA s1 type. In Southeast Asia, patients infected with vacA m1 type or cagA-positive strains have an increased risk of peptic ulcer disease. Thus, testing for this genotype and the presence of cagA may have clinical usefulness.

Differential Mechanisms for SHP2 Binding and Activation Are Exploited by Geographically Distinct Helicobacter pylori CagA Oncoproteins

Directory of Open Access Journals (Sweden)

Takeru Hayashi

2017-09-01

Full Text Available Helicobacter pylori East Asian CagA is more closely associated with gastric cancer than Western CagA. Here we show that, upon tyrosine phosphorylation, the East Asian CagA-specific EPIYA-D segment binds to the N-SH2 domain of pro-oncogenic SHP2 phosphatase two orders of magnitude greater than Western CagA-specific EPIYA-C. This high-affinity binding is achieved via cryptic interaction between Phe at the +5 position from phosphotyrosine in EPIYA-D and a hollow on the N-SH2 phosphopeptide-binding floor. Also, duplication of EPIYA-C in Western CagA, which increases gastric cancer risk, enables divalent high-affinity binding with SHP2 via N-SH2 and C-SH2. These strong CagA bindings enforce enzymatic activation of SHP2, which endows cells with neoplastic traits. Mechanistically, N-SH2 in SHP2 is in an equilibrium between stimulatory “relaxed” and inhibitory “squeezed” states, which is fixed upon high-affinity CagA binding to the “relaxed” state that stimulates SHP2. Accordingly, East Asian CagA and Western CagA exploit distinct mechanisms for SHP2 deregulation.

The EPIYA-ABCC motif pattern in CagA of Helicobacter pylori is associated with peptic ulcer and gastric cancer in Mexican population.

Science.gov (United States)

Beltrán-Anaya, Fredy Omar; Poblete, Tomás Manuel; Román-Román, Adolfo; Reyes, Salomón; de Sampedro, José; Peralta-Zaragoza, Oscar; Rodríguez, Miguel Ángel; del Moral-Hernández, Oscar; Illades-Aguiar, Berenice; Fernández-Tilapa, Gloria

2014-12-24

Helicobacter pylori chronic infection is associated with chronic gastritis, peptic ulcer, and gastric cancer. Cytotoxin-associated gene A (cagA)-positive H. pylori strains increase the risk of gastric pathology. The carcinogenic potential of CagA is linked to its polymorphic EPIYA motif variants. The goals of this study were to investigate the frequency of cagA-positive Helicobacter pylori in Mexican patients with gastric pathologies and to assess the association of cagA EPIYA motif patterns with peptic ulcer and gastric cancer. A total of 499 patients were studied; of these, 402 had chronic gastritis, 77 had peptic ulcer, and 20 had gastric cancer. H. pylori DNA, cagA, and the EPIYA motifs were detected in total DNA from gastric biopsies by PCR. The type and number of EPIYA segments were determined by the electrophoretic patterns. To confirm the PCR results, 20 amplicons of the cagA 3' variable region were sequenced, and analyzed in silico, and the amino acid sequence was predicted with MEGA software, version 5. The odds ratio (OR) was calculated to determine the associations between the EPIYA motif type and gastric pathology and between the number of EPIYA-C segments and peptic ulcers and gastric cancer. H. pylori DNA was found in 287 (57.5%) of the 499 patients, and 214 (74%) of these patients were cagA-positive. The frequency of cagA-positive H. pylori was 74.6% (164/220) in chronic gastritis patients, 73.6% (39/53) in peptic ulcer patients, and 78.6% (11/14) in gastric cancer patients. The EPIYA-ABC pattern was more frequently observed in chronic gastritis patients (79.3%, 130/164), while the EPIYA-ABCC sequence was more frequently observed in peptic ulcer (64.1%, 25/39) and gastric cancer patients (54.5%, 6/11). However, the risks of peptic ulcer (OR = 7.0, 95% CI = 3.3-15.1; p peptic ulcers and gastric cancer.

Distribution of Helicobacter pylori cagA, cagE, oipA and vacA in different major ethnic groups in Tehran, Iran.

Science.gov (United States)

Dabiri, Hossein; Maleknejad, Parviz; Yamaoka, Yoshio; Feizabadi, Mohammad M; Jafari, Fereshteh; Rezadehbashi, Maryam; Nakhjavani, Farrokh A; Mirsalehian, Akbar; Zali, Mohammad R

2009-08-01

There are geographical variations in Helicobacter pylori virulence genes; cagA, cagE, vacA and oipA. The present study compared the distribution of these genotypes in major ethnic groups residing in Tehran, Iran and their association with clinical outcomes. A total of 124 H. pylori-positive patients living in Tehran were enrolled in this study. The ethnic distribution was 74 Persians, 33 Turks and 17 other ethnics including Kurds, Lurs, Afghanis and Arabs. The presence of the cagA, cagE and oipA genes and vacA alleles (signal [s] and middle [m] region) were determined by polymerase chain reaction (PCR) from H. pylori DNA. The cagA-positive status was predominant in all three ethnic groups (e.g. 65% in Persians and 73% in Turks). In contrast, the cagE-positive status was less than half in Persians (47%) and Turks (30%), whereas it was 77% in other ethnicities (P = 0.008). The predominant vacA genotypes were s1 and m1 in all three ethnic groups (e.g. 68% in Persians and 70% in Turks were s1). There was no significant association between cagA and cagE status or vacA genotypes and clinical outcomes. The oipA-positive strains were more common in non-ulcer dyspepsia (NUD) (63%) than in peptic ulcer patients (15%) (P = 0.001) in Persians, but the association was not observed in other ethnic groups. There are some differences in the H. pylori genotypes among the ethnic groups in Iran. However, none of these markers seemed to be clinically helpful in predicting the clinical presentation of a H. pylori infection in Iran.

The frequency of Helicobacter pylor infection and cagA expression in the Korean patients with gastric carcinoma

International Nuclear Information System (INIS)

Jung, Sook Hyang; Kim, Yoo Chul

1997-12-01

Helicobacter pylori infection had been approved as a group 1 carcinogen by the international agency for research on cancer. However the association between H.pylori infection and gastric carcinoma was not so definite in South Asia including Korea, and the role of cagA gene of H.pylori in gastric carcinogenesis was a controversial issue. The aims of this study were firstly to study in vivo expression frequency of 16S rRNA and cagA gene of H.pylori, secondly to study the association between H.pylori infection and gastric cancer, the association between cagA expression and gastric cancer in Korean patients. In vivo expression rate of 16S rRNA was 74 % of gastric carcinoma patients and cagA expression rate was 51 % of gastric carcinoma patients with H.pylori infection. Although 90 % of gastric carcinoma patients had H.pylori infection, the association between H.pylori infection and gastric carcinoma was not significant. And there was no significant association between cagA expression and gastric carcinoma. (author). 37 refs., 2 tabs., 1 fig

The frequency of Helicobacter pylor infection and cagA expression in the Korean patients with gastric carcinoma

Energy Technology Data Exchange (ETDEWEB)

Jung, Sook Hyang; Kim, Yoo Chul [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

1997-12-01

Helicobacter pylori infection had been approved as a group 1 carcinogen by the international agency for research on cancer. However the association between H.pylori infection and gastric carcinoma was not so definite in South Asia including Korea, and the role of cagA gene of H.pylori in gastric carcinogenesis was a controversial issue. The aims of this study were firstly to study in vivo expression frequency of 16S rRNA and cagA gene of H.pylori, secondly to study the association between H.pylori infection and gastric cancer, the association between cagA expression and gastric cancer in Korean patients. In vivo expression rate of 16S rRNA was 74 % of gastric carcinoma patients and cagA expression rate was 51 % of gastric carcinoma patients with H.pylori infection. Although 90 % of gastric carcinoma patients had H.pylori infection, the association between H.pylori infection and gastric carcinoma was not significant. And there was no significant association between cagA expression and gastric carcinoma. (author). 37 refs., 2 tabs., 1 fig.

Different distribution of Helicobacter pylori EPIYA- cagA motifs and dupA genes in the upper gastrointestinal diseases and correlation with clinical outcomes in iranian patients.

Science.gov (United States)

Haddadi, Mohammad Hossein; Bazargani, Abdollah; Khashei, Reza; Fattahi, Mohammad Reza; Bagheri Lankarani, Kamran; Moini, Maryam; Rokni Hosseini, Seyed Mohammad Hossein

2015-01-01

Our aim was to determine the EPIYA-cagA Phosphorylation sites and dupA gene in H. pylori isolates among patients with upper gastrointestinal diseases. Pathogenicity of the cagA-positive Helicobacter pylori is associated with EPIYA motifs and higher number of EPIYA-C segments is a risk factor of gastric cancer, while duodenal ulcer-promoting gene (dupA) is determined as a protective factor against gastric cancer. A total of 280 non-repeated gastric biopsies obtained from patients undergoing endoscopy from January 2013 till July 2013. Samples were cultured on selective horse blood agar and incubated in microaerophilic atmosphere. The isolated organisms were identified as H. pylori by Gram staining and positive oxidase, catalase, and urease tests. Various motif types of cagA and the prevalence of dupA were determined by PCR method. Out of 280 specimens, 128 (54.7%) isolated organisms were identified as H. pylori. Of 120 H. pylori isolates, 35.9% were dupA positive and 56.26% were cagA positive, while cagA with ABC and ABCC motifs were 55.5% and 44.5%, respectively. Fifty six percent of the isolates with the ABCC motif have had dupA genes. We also found a significant association between strains with genotypes of dupA-ABC and duodenal ulcer disease (p = 0.007). The results of this study showed that the prevalence of cagA-positive H. pylori in Shiraz was as high as in western countries and higher numbers of EPIYA-C segments were seen in gastric cancer patients. We may also use dupA as a prognostic and pathogenic marker for duodenal ulcer disease and cagA with the segment C for gastric cancer and gastric ulcer disease in this region.

Características da gastrite crônica associada a Helicobacter pylori: aspectos topográficos, doenças associadas e correlação com o status cagA Helicobacter pylori associated gastritis: topographical pattern, associated diseases and correlation with cagA status

Directory of Open Access Journals (Sweden)

Mônica Maria Demas Álvares

2006-02-01

Full Text Available OBJETIVOS: Analisar o padrão topográfico da gastrite por H. pylori em relação ao status cagA e associação com úlcera duodenal (UD e carcinoma gástrico precoce (CaGp. MATERIAL E MÉTODO: Estudamos prospectivamente 160 biopsias endoscópicas e 40 peças de gastrectomia por CaGp. Amostras do antro e do corpo na pequena e grande curvaturas, da incisura e do tumor, foram processadas rotineiramente para histologia com histoquímica para caracterização da metaplasia intestinal (MI. O Helicobacter pylori foi avaliado por histologia, imuno-histoquímica, cultura e reação em cadeia de polimerase (PCR e o status cagA por PCR. A gastrite crônica (GC foi classificada segundo o sistema Sydney. Realizou-se estudo topográfico em 130 pacientes, analisando os parâmetros de gastrite comparativamente entre as áreas e em relação ao status cagA. RESULTADOS: Cento e vinte e um pacientes apresentaram GC, 24 UD e 14 eram normais. Detectaram-se amostras cagA-positivas em 59 pacientes com GC, 17 com UD e 24 com CaGp. Todos os parâmetros de GC foram significativamente mais intensos nos pacientes infectados por amostras cagA-positivas, que se associavam ainda à presença de atrofia e MI. A MI foi significativamente mais intensa na porção média da pequena curvatura antral do que nas demais regiões. Nos pacientes com GC e CaGp, infectados por amostras cagA-positivas, inflamação e atividade acometiam igualmente o antro e corpo distal, enquanto a atrofia e a MI predominavam no antro, particularmente na pequena curvatura do antro médio. Nos pacientes cagA-negativos a GC era predominantemente antral, e na UD a GC apresentava predominância antral, independentemente do status cagA. CONCLUSÕES: Nossos dados sugerem que o padrão de gastrite por H. pylori se relaciona com fatores de virulência da bactéria. As lesões pré-neoplásicas são significativamente mais intensas na pequena curvatura do antro médio, onde surge a maioria dos carcinomas g

Chronic infection with Helicobacter pylori does not provoke major systemic inflammation in healthy adults

DEFF Research Database (Denmark)

Brenner, H; Berg, Gabriele; Fröhlich, M

1999-01-01

It has been suggested that chronic infection with Helicobacter pylori (H. pylori), in particular infection with virulent strains producing the cytotoxin-associated protein CagA, may increase the risk of coronary heart disease by generation of a persistent low-grade inflammatory stimulus. We...... assessed the relation between serological markers of H. pylori infection and various markers of systemic inflammation in a population-based sample of 1834 men and women aged 18-88. A total of 39.3% of the sample had a positive IgG response, and among these a slight majority was CagA positive. Infection...... with H. pylori was unrelated to C-reactive protein and the leukocyte count, regardless of CagA status. There was an inverse relation between H. pylori infection and serum albumin. The adjusted OR (95% CI) of an albumin level in the bottom versus the top third were 2.2 (1.5-3.1) and 2.0 (1...

Relationship between New Allelic Types of Helicobacter pylori vacA Gene and cagA Status and Risk of GU or DU in Iran

Directory of Open Access Journals (Sweden)

S Bakhti

2015-09-01

Full Text Available Background & objectives: Several studies have described VacA and CagA as the two important virulence determinants of Helicobacter pylori, which are associated with gastric ulcer (GU and duodenal ulcer (DU. The aim of present study was to determine the associations of the i and d regions genotypes of H. pylori vacA gene and cagA status with GU and DU risk. Methods: A total of 177 isolates were cultured from the biopsies of Iranian patients with different geographic origins and genotyped. Data were collected and analyzed. Results: Frequency of the vacA i1, i2, i1i2, d1, and d2 alleles and cagA in all patients was 42.9%, 55.4%, 1.7%, 41.8%, 58.2% and 68.4%, respectively. There was a significant difference between the frequencies of vacA i1 in isolates from GU than those from non-atrophic gastritis (p<0.05. When the GU was considered as a dependant factor by the multiple logistic regression analysis, the vacA i1 genotype was significantly associated with the age- and sex-adjusted risk for GU (p=0.006, odds ratio [OR]=3.56 95% confidence interval [CI]=1.45–8.75. Statistical analysis showed no significant association between vacA d genotype and digestive diseases. After controlling for age and sex variables, the cagA genotype remained in the final model when the DU was considered as a dependant factor by the the multiple logistic regression analysis (p=0.021, OR=3.77 95% CI=1.22-11.60. Conclusion: We have proposed that the H. pylori vacA i1 and cagA genotypes could be considered as benefit biomarkers for prediction of risk of GU and DU in Iran, respectively.

Epidemiology of Helicobacter pylori and CagA-Positive Infections and Global Variations in Gastric Cancer

Science.gov (United States)

Forman, David; Crabtree, Jean E.

2018-01-01

Gastric cancer is a major health burden and is the fifth most common malignancy and the third most common cause of death from cancer worldwide. Development of gastric cancer involves several aspects, including host genetics, environmental factors, and Helicobacter pylori infection. There is increasing evidence from epidemiological studies of the association of H. pylori infection and specific virulence factors with gastric cancer. Studies in animal models indicate H. pylori is a primary factor in the development of gastric cancer. One major virulence factor in H. pylori is the cytotoxin-associated gene A (cagA), which encodes the CagA protein in the cag pathogenicity island (cag PAI). Meta-analysis of studies investigating CagA seropositivity irrespective of H. pylori status identified that CagA seropositivity increases the risk of gastric cancer (OR = 2.87, 95% CI: 1.95–4.22) relative to the risk of H. pylori infection alone (OR = 2.31, 95% CI: 1.58–3.39). Eradicating H. pylori is a strategy for reducing gastric cancer incidence. A meta-analysis of six randomised controlled trials (RCTs) suggests that searching for and eradicating H. pylori infection reduces the subsequent incidence of gastric cancer with a pooled relative risk of 0.66 (95% CI: 0.46–0.95). The introduction in regions of high gastric cancer incidence of population-based H. pylori screening and treatment programmes, with a scientifically valid assessment of programme processes, feasibility, effectiveness and possible adverse consequences, would impact the incidence of H. pylori-induced gastric cancer. Given the recent molecular understanding of the oncogenic role of CagA, targeting H. pylori screening and treatment programmes in populations with a high prevalence of H. pylori CagA-positive strains, particularly the more oncogenic East Asian H. pylori CagA strains, may be worth further investigation to optimise the benefits of such strategies. PMID:29671784

Epidemiology of Helicobacter pylori and CagA-Positive Infections and Global Variations in Gastric Cancer

Directory of Open Access Journals (Sweden)

Jin Young Park

2018-04-01

Full Text Available Gastric cancer is a major health burden and is the fifth most common malignancy and the third most common cause of death from cancer worldwide. Development of gastric cancer involves several aspects, including host genetics, environmental factors, and Helicobacter pylori infection. There is increasing evidence from epidemiological studies of the association of H. pylori infection and specific virulence factors with gastric cancer. Studies in animal models indicate H. pylori is a primary factor in the development of gastric cancer. One major virulence factor in H. pylori is the cytotoxin-associated gene A (cagA, which encodes the CagA protein in the cag pathogenicity island (cag PAI. Meta-analysis of studies investigating CagA seropositivity irrespective of H. pylori status identified that CagA seropositivity increases the risk of gastric cancer (OR = 2.87, 95% CI: 1.95–4.22 relative to the risk of H. pylori infection alone (OR = 2.31, 95% CI: 1.58–3.39. Eradicating H. pylori is a strategy for reducing gastric cancer incidence. A meta-analysis of six randomised controlled trials (RCTs suggests that searching for and eradicating H. pylori infection reduces the subsequent incidence of gastric cancer with a pooled relative risk of 0.66 (95% CI: 0.46–0.95. The introduction in regions of high gastric cancer incidence of population-based H. pylori screening and treatment programmes, with a scientifically valid assessment of programme processes, feasibility, effectiveness and possible adverse consequences, would impact the incidence of H. pylori-induced gastric cancer. Given the recent molecular understanding of the oncogenic role of CagA, targeting H. pylori screening and treatment programmes in populations with a high prevalence of H. pylori CagA-positive strains, particularly the more oncogenic East Asian H. pylori CagA strains, may be worth further investigation to optimise the benefits of such strategies.

Intact long-type DupA protein in Helicobacter pylori is an ATPase involved in multifunctional biological activities.

Science.gov (United States)

Wang, Ming-yi; Chen, Cheng; Shao, Chen; Wang, Shao-bo; Wang, Ai-chu; Yang, Ya-chao; Yuan, Xiao-yan; Shao, Shi-he

2015-04-01

The function of intact long-type DupA protein in Helicobacter pylori was analyzed using immunoblotting and molecular biology techniques in the study. After cloning, expression and purification, ATPase activity of DupA protein was detected. Antibody was produced for localization and interaction proteins analysis. The dupA-deleted mutant was generated for adhesion and CagA protein translocation assay, susceptibility to different pH, IL-8 secretion assay, cytotoxicity to MKN-45 cells and proteins-involved apoptosis analysis. DupA protein exhibited an ATPase activity (129.5±17.8 U/mgprot) and located in bacterial membrane, while it did not involve the adhesion and CagA protein delivery of H. pylori. DupA protein involved the urease secretion as the interaction proteins. The wild type strain had a stronger growth in low pH than the dupA-deleted mutant (p DupA protein located in membrane as ATPase is a true virulence factor associated with duodenal ulcer development involving the IL-8 induction and urease secretion, while it inhibits gastric cancer cell growth in vitro by activating the mitochondria-mediated apoptotic pathway. Copyright © 2015 Elsevier Ltd. All rights reserved.

Helicobacter pylori vacA and cagA genotype diversity and interferon gamma expression in patients with chronic gastritis and patients with gastric cancer.

Science.gov (United States)

Martínez-Carrillo, D N; Atrisco-Morales, J; Hernández-Pando, R; Reyes-Navarrete, S; Betancourt-Linares, R; Cruz-del Carmen, I; Illades Aguiar, B; Román-Román, A; Fernández-Tilapa, G

2014-01-01

Helicobacter pylori (H. pylori) is the main risk factor for the development of chronic gastritis, gastric ulcer, and gastric cancer. In H. pylori-infected individuals, the clinical result is dependent on various factors, among which are bacterial components, the immune response, and environmental influence. To compare IFN-γ expression with the H. pylori vacA and cagA genotypes in patients with chronic gastritis and patients with gastric cancer. Ninety-five patients diagnosed with chronic gastritis and 20 with gastric cancer were included in the study. Three gastric biopsies were taken; one was used for the molecular detection and genotyping of H. pylori; another was fixed in absolute alcohol and histologic sections were made for determining IFN-γ expression through immunohistochemistry. No differences were found in the cells that expressed IFN-γ between the patients with chronic gastritis (median percentage of positive cells: 82.6% in patients without H. pylori and 82% in infected persons) and those with gastric cancer (70.5% in H. pylori-negative patients and 78.5% in infected persons). IFN-γ expression was 69% in chronic gastritis patients infected with H. pylori vacAs2m2/cagA⁻ it was 86.5% in patients infected with H. pylori vacAs1m2/cagA⁻, 86.5% in vacAs1m1/cagA⁻, and 82% in vacAs1m1/cagA⁺. Similar data were found in the patients with gastric cancer. IFN-γ expression varied depending on the H. pylori vacA and cagA genotype, but not in accordance with the presence of chronic gastritis or gastric cancer.

A novel basolateral type IV secretion model for the CagA oncoprotein of Helicobacter pylori

Directory of Open Access Journals (Sweden)

Silja Wessler

2017-12-01

Full Text Available Intercellular junctions are crucial structural elements for the formation and maintenance of epithelial barrier functions to control homeostasis or protect against intruding pathogens in humans. Alterations in these complexes represent key events in the development and progression of numerous cancers as well as multiple infectious diseases. Many bacterial pathogens harbor type IV secretion systems (T4SSs, which translocate virulence factors into host cells to hijack cellular processes. The pathology of the gastric pathogen and type-I carcinogen Helicobacter pylori strongly depends on a T4SS encoded by the cag pathogenicity island (cagPAI. This T4SS forms a needle-like pilus and its activity is accomplished by the pilus-associated factors CagL, CagI and CagY which target the host integrin-β1 receptor followed by injection of the CagA oncoprotein into non-polarized AGS gastric epithelial cells. The finding of a T4SS receptor, however, suggested the presence of a sophisticated control mechanism for the injection of CagA. In fact, integrins constitute a group of basolateral receptors, which are normally absent at apical surfaces of the polarized epithelium in vivo. Our new results demonstrate that T4SS-pilus formation during H. pylori infection of polarized epithelial cells occurs preferentially at basolateral sites, and not at apical membranes (Tegtmeyer et al., 2017. We propose a stepwise process how H. pylori interacts with components of intercellular tight junctions (TJs and adherens junctions (AJs, followed by contacting integrin-based focal adhesions to disrupt and transform the epithelial cell layer in the human stomach. The possible impact of this novel signaling cascade on pathogenesis during infection is reviewed.

Molecular interactions between MUC1 epithelial mucin, β-catenin, and CagA proteins

Directory of Open Access Journals (Sweden)

Wei eGuang

2012-05-01

Full Text Available Interleukin (IL-8-driven neutrophil infiltration of the gastric mucosa is pathognomonic of persistent Helicobacter pylori infection. Our prior study showed that ectopic over-expression of MUC1 in human AGS gastric epithelial cells reduced H. pylori-stimulated IL-8 production compared with cells expressing MUC1 endogenously. Conversely, Muc1 knockout (Muc1-/- mice displayed an increased level of transcripts encoding the keratinocyte chemoattractant (KC, the murine equivalent of human IL-8, in gastric mucosa compared with Muc1(+/+ mice during experimental H. pylori infection. The current study tested the hypothesis that a decreased IL-8 level observed following MUC1 over-expression is mediated through the ability of MUC1 to associate with β-catenin, thereby inhibiting H. pylori-induced β-catenin nuclear translocation. Increased neutrophil infiltration of the gastric mucosa of H. pylori-infected Muc1(-/- mice was observed compared with Muc1(+/+ wild type littermates, thus defining the functional consequences of increased KC expression in the Muc1-null animals. Protein co-immunoprecipitation (coIP studies using lysates of untreated or H. pylori-treated AGS cells demonstrated that (a MUC1 formed a coIP complex with β-catenin and CagA, (b MUC1 over-expression reduced CagA/β-catenin coIP, and (c in the absence of MUC1 over-expression, H. pylori infection increased the nuclear level of β-catenin, (d whereas MUC1 over-expression decreased bacteria-driven β-catenin nuclear localization. These results suggest that manipulation of MUC1 expression in gastric epithelia may be an effective therapeutic strategy to inhibit H. pylori-dependent IL-8 production, neutrophil infiltration, and stomach inflammation.

VacA and CagA Status as Biomarker of Two Opposite End Outcomes of Helicobacter pylori Infection (Gastric Cancer and Duodenal Ulcer) in a Moroccan Population

OpenAIRE

El Khadir, Mounia; Alaoui Boukhris, Samia; Benajah, Dafr-Allah; El Rhazi, Karima; Ibrahimi, Sidi Adil; El Abkari, Mohamed; Harmouch, Taoufiq; Nejjari, Chakib; Mahmoud, Mustapha; Benlemlih, Mohamed; Bennani, Bahia

2017-01-01

Helicobacter pylori (H. pylori) infection induces inflammation of the gastric mucosa, which may progress to precancerous lesions leading to gastric cancer. Pathological determinism is associated to some virulence genes of the bacterium, notably the vacA and cagA genes. The present study aimed to determine the H. pylori genotypes distribution and their association with sex, age and gastric diseases in a Moroccan population. Gastric biopsy was taken from 1079 consenting patients. The specimens ...

Clonación y expresión de un fragmento recombinante del gen cagA de Helicobacter pylori y su evaluación preliminar en el serodiagnóstico

Directory of Open Access Journals (Sweden)

Lidice González

2013-12-01

100 % y 92,7 %, respectivamente. Conclusiones. El fragmento de la proteína CagA del estudio puede constituir una herramienta útil para el diagnóstico serológico de la infección por cepas de H. pylori positivas para CagA. doi: http://dx.doi.org/10.7705/biomedica.v33i4.1678

Infección por Helicobacter pylori en la Ciudad de La Habana, Cuba.Prevalencia de las cepas cagA positivas

Directory of Open Access Journals (Sweden)

Beatriz Gutiérrez

2005-12-01

Full Text Available Existe una gran falta de información acerca de la infección por Helicobacter pylori en los países de la región del Caribe. Nuestros objetivos en este estudio fueron determinar la prevalencia, la resistencia a los antibióticos y los factores de virulencia de la bacteria. La medida de la prevalencia de la infección por H. pylori se determinó en un grupo de pacientes a los que se les practicó una endoscopia en tres centros hospitalarios de La Ciudad de La Habana, lo que nos permitió evaluar la resistencia a la claritromicina y la presencia de cagA + en las cepas obtenidas. De las endoscopias realizadas se obtuvieron 117 biopsias gástricas, procedentes de tres centros hospitalarios de La Ciudad de La Habana, Cuba: Instituto de Oncología, Instituto de Gastroenterología y el Hospital Calixto García. Las biopsias fueron mantenidas a –70 ºC para posterior cultivo en tres medios diferentes (dos selectivos y uno no selectivo y su posterior incubación por 7 días a 37 ºC en una atmósfera de microaerofilia. La presencia de H. pylori fue identificada por la presencia de diferentes enzimas (oxidasa, catalasa, ureasa. Se realizó la extracción del DNA y la PCR, donde se utilizó el primer H2761676 y se amplificó con 397 fragmentos del gen cagA. La susceptibilidad a la claritromicina fue medida por el método de difusión en gel. Diagnóstico endoscópico: (1 cáncer gástrico; (19 úlcera duodenal; (8 úlcera gástrica; (89 dispepsias no ulcerosas, incluyendo (62 gastritis; (9 hernia hiatal; (2 reflujo biliar; (1 pólipo gástrico; (15 panendoscopias normales. Del total de 117 biopsias realizadas, 83 fueron positivas a la infección por H.pylori (70,9% . De las 35 cepas a las que se les realizó presencia de cagA+ resultaron positivas 31 (88,5%. Solo el 3% de las cepas fueron resistentes a la claritromicina. La prevalencia de la infección por H. pylori en la población sintomática de La Ciudad de La Habana es la misma que la reportada en

Helicobacter pylori iceA, clinical outcomes, and correlation with cagA: a meta-analysis.

Science.gov (United States)

Shiota, Seiji; Watada, Masahide; Matsunari, Osamu; Iwatani, Shun; Suzuki, Rumiko; Yamaoka, Yoshio

2012-01-01

Although the iceA (induced by contact with epithelium) allelic types of Helicobacter pylori have been reported to be associated with peptic ulcer, the importance of iceA on clinical outcomes based on subsequent studies is controversial. The aim of this study was to estimate the magnitude of the risk for clinical outcomes associated with iceA. A literature search was performed using the PubMed and EMBASE databases for articles published through April 2011. Published case-control studies examining the relationship between iceA and clinical outcomes (gastritis, peptic ulcer, including gastric ulcer and duodenal ulcer, and gastric cancer) were included. Fifty studies with a total of 5,357 patients were identified in the search. Infection with iceA1-positive H. pylori increased the overall risk for peptic ulcer by 1.26-fold (95% confidence interval [CI], 1.09-1.45). However, the test for heterogeneity was significant among these studies. Sensitivity analysis showed that the presence of iceA1 was significantly associated with peptic ulcer (odds ratio [OR] = 1.25, 95% CI = 1.08-1.44). The presence of iceA2 was inversely associated with peptic ulcer (OR = 0.76, 95% CI = 0.65-0.89). The presence of iceA was not associated with gastric cancer. Most studies examined the cagA status; however, only 15 studies examined the correlation and only 2 showed a positive correlation between the presence of cagA and iceA1. Our meta-analysis confirmed the importance of the presence of iceA for peptic ulcer, although the significance was marginal.

In vitro effect of amoxicillin and clarithromycin on the 3’ region of cagA gene in Helicobacter pylori isolates

Science.gov (United States)

Bustamante-Rengifo, Javier Andrés; Matta, Andrés Januer; Pazos, Alvaro; Bravo, Luis Eduardo

2013-01-01

AIM: To evaluate the in vitro effect of amoxicillin and clarithromycin on the cag pathogenicity island (cag PAI). METHODS: One hundred and forty-nine clinical isolates of Helicobacter pylori (H. pylori) cultured from gastric biopsies from 206 Colombian patients with dyspeptic symptoms from a high-risk area for gastric cancer were included as study material. Antimicrobial susceptibility was determined by the agar dilution method. Resistant isolates at baseline and in amoxicillin and clarithromycin serial dilutions were subjected to genotyping (cagA, vacA alleles s and m), Glu-Pro-Ile-Tyr-Ala (EPIYA) polymerase chain reaction and random amplified polymorphic DNA (RAPD). Images of the RAPD amplicons were analyzed by Gel-Pro Analyzer 4.5 program. Cluster analyses was done using SPSS 15.0 statistical package, where each of the fingerprint bands were denoted as variables. Dendrograms were designed by following Ward’s clustering method and the estimation of distances between each pair of H. pylori isolates was calculated with the squared Euclidean distance. RESULTS: Resistance rates were 4% for amoxicillin and 2.7% for clarithromycin with 2% double resistances. Genotyping evidenced a high prevalence of the genotype cagA-positive/vacA s1m1. The 3’ region of cagA gene was successfully amplified in 92.3% (12/13) of the baseline resistant isolates and in 60% (36/60) of the resistant isolates growing in antibiotic dilutions. Upon observing the distribution of the number of EPIYA repetitions in each dilution with respect to baseline isolates, it was found that in 61.5% (8/13) of the baseline isolates, a change in the number of EPIYA repetitions lowered antibiotic pressure. The gain and loss of EPIYA motifs resulted in a diversity of H. pylori subclones after bacterial adjustment to changing conditions product of antibiotic pressure. RAPD PCR evidenced the close clonal relationship between baseline isolates and isolates growing in antibiotic dilutions. CONCLUSION: Antibiotic

CagA-positive Helicobacter pylori infection is not associated with decreased risk of Barrett's esophagus in a population with high H. pylori infection rate

Directory of Open Access Journals (Sweden)

Ortego Javier

2006-02-01

Full Text Available Abstract Background & aim The role that H. pylori infection plays in the development of and Barrett's esophagus (BE is uncertain. We tested the hypothesis that infection with cagA+ Helicobacter pylori strains protects against the development of BE. Methods We studied 104 consecutive patients, residents in an area with a high prevalence of H. pylori infection, with BE and 213 sex- and age-matched controls. H. pylori infection and CagA antibody status were determined by western blot serology. Results H. pylori prevalence was higher in patients with BE than in controls (87.5% vs. 74.6%; OR. 2.3; 95% CI: 1.23–4.59. Increasing age was associated with a higher prevalence of H. pylori (p Conclusion Neither H. pylori infection nor H. pylori infection by CagA+ strains reduce the risk of BE in a population with high prevalence of H. pylori infection.

Distribution of Helicobacter pylori cagA, cagE and vacA in different ethnic groups in Kuala Lumpur, Malaysia.

Science.gov (United States)

Tan, Huck Joo; Rizal, Abdul Manaf; Rosmadi, Mohamed-Yusoff; Goh, Khean-Lee

2005-04-01

There is a geographic variation in Helicobacter pylori (HP) genotypes and virulence factors. Cytotoxin associated genes A (cagA) and E (cagE), and certain vacuolating cytotoxin (vacA) genotypes are associated with peptic ulcer disease (PUD). There is also a different prevalence of PUD among different ethnic groups in Malaysia. The present study compared the distribution of vacA alleles and cagA and cagE status in three ethnic groups residing in Kuala Lumpur, Malaysia, and their association with clinical outcome. All patients with cultured positive HP were recruited prospectively. DNA was extracted and polymerase chain reaction was carried out to determine the cagA and cagE status and vacA alleles. The results of 127 patients (72 men and 55 women) were included. The mean age was 55.53 +/- 12.52 years. The ethnic distribution was 59 Chinese, 38 Indian and 30 Malay patients. The predominant genotype was s1a among the Malay (76.6%) and Indian patients (71.0%), and s1c among the Chinese patients (66.1%). The vacA middle region sequence m1 was detected in 66.7% of Malay, 54.2% of Chinese and 76.3% of Indian patients. Of the Malay, Chinese and Indian patients, 76.6%, 86.4% and 86.8%, respectively, were cagA positive, and 70.0%, 39.0% and 81.6%, respectively, were cagE positve. HP cagA, cagE and vacA were not associated with PUD. There is a distinctive difference in the HP strains among the three ethnic groups in Malaysia. There was no association between cagA, cagE or vacA genotypes and clinical outcome in the patients. None of these markers are helpful in predicting the clinical presentation of a HP infection.

Performance of a Multiplex Serological Helicobacter pylori Assay on a Novel Microfluidic Assay Platform

Directory of Open Access Journals (Sweden)

Angela Filomena

2017-10-01

Full Text Available Infection with Helicobacter pylori (H. pylori occurs in 50% of the world population, and is associated with the development of ulcer and gastric cancer. Serological diagnostic tests indicate an H. pylori infection by detecting antibodies directed against H. pylori proteins. In addition to line blots, multiplex assay platforms provide smart solutions for the simultaneous analysis of antibody responses towards several H. pylori proteins. We used seven H. pylori proteins (FliD, gGT, GroEL, HpaA, CagA, VacA, and HP0231 and an H. pylori lysate for the development of a multiplex serological assay on a novel microfluidic platform. The reaction limited binding regime in the microfluidic channels allows for a short incubation time of 35 min. The developed assay showed very high sensitivity (99% and specificity (100%. Besides sensitivity and specificity, the technical validation (intra-assay CV = 3.7 ± 1.2% and inter-assay CV = 5.5 ± 1.2% demonstrates that our assay is also a robust tool for the analysis of the H. pylori-specific antibody response. The integration of the virulence factors CagA and VacA allow for the assessment of the risk for gastric cancer development. The short assay time and the performance of the platform shows the potential for implementation of such assays in a clinical setting.

Human Gastric Mucosal Hydrophobicity Does dot Decrease with Helicobacter Pylori Infection or Chronological Age

Directory of Open Access Journals (Sweden)

Mohammed S Al-Marhoon

2005-01-01

Full Text Available BACKGROUND AND AIMS: Infection with cytotoxin-associated gene A (cagA Helicobacter pylori is associated with severe gastric diseases. Previous studies in humans have reported a decreased gastric hydrophobicity with H pylori infection. The aim of the present study was to differentiate between the effect of cagA+ and cagA- strains on gastric mucus hydrophobicity.

Genotyping of Helicobacter pylori Strains Isolated from Patients with Gastric Ulcer and Non Ulcer Disease using RFLP-PCR of ureAB, vacA , cagA Genes

Directory of Open Access Journals (Sweden)

Sh. Farshad

2008-10-01

Full Text Available Introduction & Objective: Different studies show that the reasons for clinically diverse outcomes of infections caused by H. pylori may include host and environmental factors as well as differences in the prevalence or expression of bacterial virulence factors. The aim of this study was to study the distribution of different genotypes of major virulence factors cagA, vacA and ureAB among H. pylori strains isolated from patients with gastric ulcer (ulcerative disease and patients with gastritis (non ulcerative disease.Materials & Methods: In this cross sectional study 65 H. pylori strains, 30 from patients with gastric ulcer and 35 from patients with non ulcerative gastritis disease were investigated by RFLP-PCR.Results: The prevalence of vacA-positive strains in ulcerative patients was significantly more than that in non ulcerative patients (P0.05.Conclusion: It seems that in the patients under our study the presence of cagA gene may not necessarily be a risk factor for ulcer disease, while a homologous genotype of vacA appears to be associated with an increase risk of ulcer development. Lastly, despite the existence of a high degree of genomic variability within ureAB, conserved DNA banding profiles are distributed in our areas.

Disease association with two Helicobacter pylori duplicate outer membrane protein genes, homB and homA.

Science.gov (United States)

Oleastro, Monica; Cordeiro, Rita; Yamaoka, Yoshio; Queiroz, Dulciene; Mégraud, Francis; Monteiro, Lurdes; Ménard, Armelle

2009-06-22

homB encodes a Helicobacter pylori outer membrane protein. This gene was previously associated with peptic ulcer disease (PUD) and was shown to induce activation of interleukin-8 secretion in vitro, as well as contributing to bacterial adherence. Its 90%-similar gene, homA, was previously correlated with gastritis. The present study aimed to evaluate the gastric disease association with homB and homA, as well as with the H. pylori virulence factors cagA, babA and vacA, in 415 H. pylori strains isolated from patients from East Asian and Western countries. The correlation among these genotypes was also evaluated. Both homB and homA genes were heterogeneously distributed worldwide, with a marked difference between East Asian and Western strains. In Western strains (n = 234, 124 PUD and 110 non-ulcer dyspepsia (NUD), homB, cagA and vacA s1 were all significantly associated with PUD (p = 0.025, p = 0.014, p = 0.039, respectively), and homA was closely correlated with NUD (p = 0.072). In East Asian strains (n = 138, 73 PUD and 65 NUD), homB was found more frequently than homA, and none of these genes was associated with the clinical outcome. Overall, homB was associated with the presence of cagA (p = 0.043) and vacA s1 (p homA was found more frequently in cagA-negative (p = 0.062) and vacA s2 (p homA copy number were observed, with a clear geographical specificity, suggesting an involvement of these genes in host adaptation. A correlation between the homB two-copy genotype and PUD was also observed, emphasizing the role of homB in the virulence of the strain. The global results suggest that homB and homA contribute to the determination of clinical outcome.

A Global Overview of the Genetic and Functional Diversity in the Helicobacter pylori cag Pathogenicity Island

Science.gov (United States)

Moodley, Yoshan; Uhr, Markus; Stamer, Christiana; Vauterin, Marc; Suerbaum, Sebastian; Achtman, Mark

2010-01-01

The Helicobacter pylori cag pathogenicity island (cagPAI) encodes a type IV secretion system. Humans infected with cagPAI–carrying H. pylori are at increased risk for sequelae such as gastric cancer. Housekeeping genes in H. pylori show considerable genetic diversity; but the diversity of virulence factors such as the cagPAI, which transports the bacterial oncogene CagA into host cells, has not been systematically investigated. Here we compared the complete cagPAI sequences for 38 representative isolates from all known H. pylori biogeographic populations. Their gene content and gene order were highly conserved. The phylogeny of most cagPAI genes was similar to that of housekeeping genes, indicating that the cagPAI was probably acquired only once by H. pylori, and its genetic diversity reflects the isolation by distance that has shaped this bacterial species since modern humans migrated out of Africa. Most isolates induced IL-8 release in gastric epithelial cells, indicating that the function of the Cag secretion system has been conserved despite some genetic rearrangements. More than one third of cagPAI genes, in particular those encoding cell-surface exposed proteins, showed signatures of diversifying (Darwinian) selection at more than 5% of codons. Several unknown gene products predicted to be under Darwinian selection are also likely to be secreted proteins (e.g. HP0522, HP0535). One of these, HP0535, is predicted to code for either a new secreted candidate effector protein or a protein which interacts with CagA because it contains two genetic lineages, similar to cagA. Our study provides a resource that can guide future research on the biological roles and host interactions of cagPAI proteins, including several whose function is still unknown. PMID:20808891

Frequency of virulence factors in Helicobacter pylori-infected patients with gastritis.

Science.gov (United States)

Salimzadeh, Loghman; Bagheri, Nader; Zamanzad, Behnam; Azadegan-Dehkordi, Fatemeh; Rahimian, Ghorbanali; Hashemzadeh-Chaleshtori, Morteza; Rafieian-Kopaei, Mahmoud; Sanei, Mohammad Hossein; Shirzad, Hedayatollah

2015-03-01

The outcome of Helicobacter pylori infection has been related to specific virulence-associated bacterial genotypes. The vacuolating cytotoxin (vacA), cagA gene, oipA and babA2 gene are important virulence factor involving gastric diseases. The objective of this study was to assess the relationship between virulence factors of H. pylori and histopathological findings. Gastroduodenoscopy was performed in 436 dyspeptic patients. Antrum biopsy was obtained for detection of H. pylori, virulence factors and for histopathological assessment. The polymerase chain reaction was used to detect virulence factors of H. pylori using specific primers. vacA genotypes in patients infected with H. pylori were associated with cagA, iceA1 and iceA2. In the patients with H. pylori infection there was a significant relationship between cagA positivity and neutrophil activity (P = 0.004) and chronic inflammation (P = 0.013) and with H. pylori density (P = 0.034). Neutrophil infiltration was found to be more severe in the s1 group than in the s2 group (P = 0.042). Also was a significant relationship between oipA positivity and neutrophil activity (P = 0.004) and with H. pylori density (P = 0.018). No significant relationships were observed between other vacA genotypes and histopathological parameters. H. pylori strains showing cagA, vacA s1 and oipA positivity are associated with more severe gastritis in some histological features but virulence factors of H. pylori do not appear to determine the overall pattern of gastritis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Helicobacter pylori induces cell migration and invasion through casein kinase 2 in gastric epithelial cells.

Science.gov (United States)

Lee, Yeo Song; Lee, Do Yeon; Yu, Da Yeon; Kim, Shin; Lee, Yong Chan

2014-12-01

Chronic infection with Helicobacter pylori (H. pylori) is causally linked with gastric carcinogenesis. Virulent H. pylori strains deliver bacterial CagA into gastric epithelial cells. Induction of high motility and an elongated phenotype is considered to be CagA-dependent process. Casein kinase 2 plays a critical role in carcinogenesis through signaling pathways related to the epithelial mesenchymal transition. This study was aimed to investigate the effect of H. pylori infection on the casein kinase 2-mediated migration and invasion in gastric epithelial cells. AGS or MKN28 cells as human gastric epithelial cells and H. pylori strains Hp60190 (ATCC 49503, CagA(+)) and Hp8822 (CagA(-)) were used. Cells were infected with H. pylori at multiplicity of infection of 100 : 1 for various times. We measured in vitro kinase assay to examine casein kinase 2 activity and performed immunofluorescent staining to observe E-cadherin complex. We also examined β-catenin transactivation through promoter assay and MMP7 expression by real-time PCR and ELISA. H. pylori upregulates casein kinase 2 activity and inhibition of casein kinase 2 in H. pylori-infected cells profoundly suppressed cell invasiveness and motility. We confirmed that casein kinase 2 mediates membranous α-catenin depletion through dissociation of the α-/β-catenin complex in H. pylori-infected cells. We also found that H. pylori induces β-catenin nuclear translocation and increases MMP7 expressions mediated through casein kinase 2. We show for the first time that CagA(+) H. pylori upregulates cellular invasiveness and motility through casein kinase 2. The demonstration of a mechanistic interplay between H. pylori and casein kinase 2 provides important insights into the role of CagA(+) H. pylori in the gastric cancer invasion and metastasis. © 2014 John Wiley & Sons Ltd.

Relationship between caga-positive Helicobacter pylori infection and risk of gastric cancer: a case control study in Porto Alegre, RS, Brazil

Directory of Open Access Journals (Sweden)

Gilmara Coelho Meine

2011-03-01

Full Text Available CONTEXT: Gastric cancer is the second most common cause of cancer related death worldwide. Although Helicobacter pylori has been classified as a class I carcinogen, the presence of infection is not a factor that alone is able to lead to gastric cancer, and one of the possible explanations for this is the existence of different strains of H. pylori with different degrees of virulence. OBJECTIVES: To investigate the association between cagA-positive H. pylori and gastric cancer, using polymerase chain reaction (PCR for the detection of this bacterial strain. METHODS: Twenty-nine patients with gastric cancer were matched by sex and age (± 5 years with 58 patients without gastric cancer, submitted to upper gastrointestinal endoscopy. All patients were evaluated for the status of infection by H. pylori (through urease test, histological analysis and PCR for the genes ureA and 16SrRNA and by cagA-positive strain (through PCR for cagA gene. RESULTS: Evaluating the presence of infection by cagA-positive H. pylori, it was verified that the rate of infection was significantly higher in the group with gastric cancer when compared with the matched controls, occurring in 62.1% and 29.3%, respectively (OR = 3.95; CI 95% 1.543-10.096. CONCLUSIONS: There is an association between cagA-positive H. pylori strain and risk of gastric cancer.

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

Science.gov (United States)

Fernández-de-Larrea, Nerea; Michel, Angelika; Romero, Beatriz; Butt, Julia; Pawlita, Michael; Pérez-Gómez, Beatriz; Castaño-Vinyals, Gemma; Moreno, Victor; Martín, Vicente; Amiano, Pilar; Castilla, Jesús; Fernández-Tardón, Guillermo; Dierssen-Sotos, Trinidad; Clofent, Juan; Alguacil, Juan; Huerta, José María; Jiménez-Moleón, José Juan; Barricarte, Aurelio; Molinuevo, Amaia; Fernández-Villa, Tania; Casabonne, Delphine; Sierra, Ángeles; Kogevinas, Manolis; de Sanjosé, Silvia; Pollán, Marina; Del Campo, Rosa; Waterboer, Tim; Aragonés, Nuria

2017-10-01

Differences in Helicobacter pylori protein expression have been related to the risk of severe gastric diseases. In Spain, a marked geographic pattern in gastric cancer mortality has long been reported. To characterize antibody reactivity patterns against 16 H. pylori proteins, by age, sex, and region of birth, in a large sample of the Spanish adult population. Antibody reactivity was quantified by H. pylori multiplex serology in a sample from the control group of the multicase-control study MCC-Spain. For this analysis, 2555 population-based controls were included. Each participant was classified as seropositive or seronegative for each protein according to specific cutoffs. Overall H. pylori seroprevalence was defined as positivity against ≥4 proteins. Descriptive analyses by age, sex, and region of birth were performed for both seroprevalence and seroreactivity (continuous measure). Differences among groups were tested by logistic and linear regression models. Overall H. pylori seroprevalence increased with age in both sexes. For ages 55-74, seroprevalence was lower in women than in men (84% vs 92%, Ppylori seropositive subjects, proteins with the highest seroprevalence were GroEL, NapA, HP231, and Omp. Seropositivity for most of the proteins increased or remained stable with age, rising mainly for CagA, GroEL, and HyuA in women. A clear cohort effect was not observed. This is the first study to describe the antibody patterns against 16 H. pylori proteins in the Spanish population. We found variability in the H. pylori antibody profiles according to both individual factors such as age and sex, and environmental factors such as the region of birth. The slightness of the reduction in seropositivity with decreasing age highlights the ongoing importance of this infection. © 2017 John Wiley & Sons Ltd.

The Role of Helicobacter pylori Outer Membrane Proteins in Adherence and Pathogenesis

Science.gov (United States)

Oleastro, Mónica; Ménard, Armelle

2013-01-01

Helicobacter pylori is one of the most successful human pathogens, which colonizes the mucus layer of the gastric epithelium of more than 50% of the world’s population. This curved, microaerophilic, Gram-negative bacterium induces a chronic active gastritis, often asymptomatic, in all infected individuals. In some cases, this gastritis evolves to more severe diseases such as peptic ulcer disease, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. H. pylori has developed a unique set of factors, actively supporting its successful survival and persistence in its natural hostile ecological niche, the human stomach, throughout the individual’s life, unless treated. In the human stomach, the vast majority of H. pylori cells are motile in the mucus layer lining, but a small percentage adheres to the epithelial cell surfaces. Adherence to the gastric epithelium is important for the ability of H. pylori to cause disease because this intimate attachment facilitates: (1) colonization and persistence, by preventing the bacteria from being eliminated from the stomach, by mucus turnover and gastric peristalsis; (2) evasion from the human immune system and (3) efficient delivery of proteins into the gastric cell, such as the CagA oncoprotein. Therefore, bacteria with better adherence properties colonize the host at higher densities. H. pylori is one of the most genetically diverse bacterial species known and is equipped with an extraordinarily large set of outer membrane proteins, whose role in the infection and persistence process will be discussed in this review, as well as the different receptor structures that have been so far described for mucosal adherence. PMID:24833057

The Role of Helicobacter pylori Outer Membrane Proteins in Adherence and Pathogenesis

Directory of Open Access Journals (Sweden)

Armelle Ménard

2013-08-01

Full Text Available Helicobacter pylori is one of the most successful human pathogens, which colonizes the mucus layer of the gastric epithelium of more than 50% of the world’s population. This curved, microaerophilic, Gram-negative bacterium induces a chronic active gastritis, often asymptomatic, in all infected individuals. In some cases, this gastritis evolves to more severe diseases such as peptic ulcer disease, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. H. pylori has developed a unique set of factors, actively supporting its successful survival and persistence in its natural hostile ecological niche, the human stomach, throughout the individual’s life, unless treated. In the human stomach, the vast majority of H. pylori cells are motile in the mucus layer lining, but a small percentage adheres to the epithelial cell surfaces. Adherence to the gastric epithelium is important for the ability of H. pylori to cause disease because this intimate attachment facilitates: (1 colonization and persistence, by preventing the bacteria from being eliminated from the stomach, by mucus turnover and gastric peristalsis; (2 evasion from the human immune system and (3 efficient delivery of proteins into the gastric cell, such as the CagA oncoprotein. Therefore, bacteria with better adherence properties colonize the host at higher densities. H. pylori is one of the most genetically diverse bacterial species known and is equipped with an extraordinarily large set of outer membrane proteins, whose role in the infection and persistence process will be discussed in this review, as well as the different receptor structures that have been so far described for mucosal adherence.

Patrón de los motivos EPIYA de cepas cubanas de Helicobacter pylori positivas para CagA

Directory of Open Access Journals (Sweden)

Lino E. Torres

2012-03-01

Conclusión. La mayoría de los aislamientos cubanos presentaron las combinaciones de motivos EPIYA menos virulentas (ABC. Los resultados del empleo de los nuevos cebadores y el análisis de la secuenciación, confirmaron que todas las cepas estudiadas portaban el gen cagA de tipo occidental. Ninguno de los patrones específicos de EPIYA se asoció con úlcera péptica. Este es el primer reporte que muestra la distribución de los motivos EPIYA en los aislamientos de H. pylori de la región del Caribe.   DOI: http://dx.doi.org/10.7705/biomedica.v32i1.453

Regulation of the actin cytoskeleton in Helicobacter pylori-induced migration and invasive growth of gastric epithelial cells

Directory of Open Access Journals (Sweden)

Rieder Gabriele

2011-11-01

Full Text Available Abstract Dynamic rearrangement of the actin cytoskeleton is a significant hallmark of Helicobacter pylori (H. pylori infected gastric epithelial cells leading to cell migration and invasive growth. Considering the cellular mechanisms, the type IV secretion system (T4SS and the effector protein cytotoxin-associated gene A (CagA of H. pylori are well-studied initiators of distinct signal transduction pathways in host cells targeting kinases, adaptor proteins, GTPases, actin binding and other proteins involved in the regulation of the actin lattice. In this review, we summarize recent findings of how H. pylori functionally interacts with the complex signaling network that controls the actin cytoskeleton of motile and invasive gastric epithelial cells.

Association between Helicobacter pylori Virulence Factors and Gastroduodenal Diseases in Okinawa, Japan

Science.gov (United States)

Matsunari, Osamu; Shiota, Seiji; Suzuki, Rumiko; Watada, Masahide; Kinjo, Nagisa; Murakami, Kazunari; Fujioka, Toshio; Kinjo, Fukunori

2012-01-01

The incidence of gastric cancer in Okinawa is lowest in Japan. Some previous reports using small number of strains suggested that the high prevalence of Helicobacter pylori with Western-type cagA in Okinawa compared to other areas in Japan might contribute to the low incidence of gastric cancer. It has still not been confirmed why the prevalence of Western-type cagA strains is high in Okinawa. We examined the association between the virulence factors of H. pylori and gastroduodenal diseases in Okinawa. The genotypes of cagA and vacA of 337 H. pylori strains were determined by PCR and gene sequencing. The genealogy of these Western-type cagA strains in Okinawa was analyzed by multilocus sequence typing (MLST). Overall, 86.4% of the strains possessed cagA: 70.3% were East-Asian type and 16.0% were Western type. After adjustment by age and sex, the presence of East-Asian-type cagA/vacA s1m1 genotypes was significantly associated with gastric cancer compared to gastritis (odds ratio = 6.68, 95% confidence interval = 1.73 to 25.8). The structure of Western-type CagA in Okinawa was different from that of typical Western-type CagA found in Western countries. Intriguingly, MLST analysis revealed that the majority of Western-type cagA strains formed individual clusters but not hpEurope. Overall, low prevalence of gastric cancer in Okinawa may result from the high prevalence of non-East-Asian-type cagA strains. The origin of Western-type cagA strains in Okinawa may be different from those of Western countries. PMID:22189111

VacA, cagA, iceA and oipA genotypes status and antimicrobial resistance properties of Helicobacter pylori isolated from various types of ready to eat foods.

Science.gov (United States)

Hemmatinezhad, Behsan; Momtaz, Hassan; Rahimi, Ebrahim

2016-01-20

Despite the high clinical standing of Helicobacter pylori, its exact routes of transmission and origin have not been determined. Based on the contentious hypothesis, foods play an important roles in the transmission of H. pylori to humans. The present study was carried out to investigate the vacA, cagA, oipA and iceA genotypes status of H. pylori isolated from the various types of ready to eat foods. A total of 550 ready to eat food samples were cultured and tested. H. pylori-positive strains were analyzed for the presence of various genotypes and antimicrobial resistance pattern. Seventy four out of 550 (13.45 %) samples were positive for H. pylori. Olvie salad (36 %), restaurant salad (30 %), fruit salad (28 %) and soup (22 %) were the most commonly contaminated. H. pylori strains harbored the highest levels of resistance against amoxicillin (94.59 %), ampicillin (93.24 %), metronidazole (89.18 %) and tetracycline (72.97 %). The most commonly detected genotypes were vacA s1a (78.37 %), vacA m2 (75.67 %), vacA m1a (51.35 %) and cagA (41.89 %). The prevalence of iceA1, iceA2 and oipA genotypes were 13.51, 4.05 and 18.91 %, respectively. S1am2 (70.27 %), s1am1a (39.18 %) and m1am2 (31.08 %) were the most commonly detected combined genotypes. Of 40 different genotypic combinations, s1a/cagA+/iceA1/oipA- (12.16 %), s1a/cagA+/iceA1/oipA+ (10.81 %) and s1a/cagA-/iceA1/oipA+ (10.81 %) were the most prevalent. The present investigation showed that some types of ready to eat food samples maybe the sources of resistant and virulent strains of H. pylori. Warily use of antibiotics with respect to the results of disk diffusion method and careful health monitoring on food and staffs of food producing companies maybe reduce the risk of H. pylori in foods.

The significance of virulence factors in Helicobacter pylori.

Science.gov (United States)

Shiota, Seiji; Suzuki, Rumiko; Yamaoka, Yoshio

2013-07-01

Helicobacter pylori (H. pylori) infection is linked to various gastroduodenal diseases; however, only a small fraction of these patients develop associated diseases. Despite the high prevalence of H. pylori infection in Africa and South Asia, the incidence of gastric cancer in these areas is much lower than those in other countries. The incidence of gastric cancer tends to decrease from north to south in East Asia. Such geographical differences in the pathology can be explained, at least in part, by the presence of different types of H. pylori virulence factors in addition to host and environmental factors. Virulence factors of H. pylori, such as CagA, VacA, DupA, IceA, OipA and BabA, have been demonstrated to be the predictors of severe clinical outcomes. Interestingly, a meta-analysis showed that CagA seropositivity was associated with gastric cancer compared with gastritis, even in East Asian countries where almost the strains possess cagA. Another meta-analysis also confirmed the significance of vacA, dupA and iceA. However, it is possible that additional important pathogenic genes may exist because H. pylori consists of approximately 1600 genes. Despite the advances in our understanding of the development of H. pylori infection-related diseases, further work is required to clarify the roles of H. pylori virulence factors. © 2013 The Authors. Journal of Digestive Diseases © 2013 Wiley Publishing Asia Pty Ltd and Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine.

Virulence genes of Helicobacter pylori in gastritis, peptic ulcer and gastric cancer in Laos.

Science.gov (United States)

Vannarath, Sengdao; Vilaichone, Ratha-korn; Rasachak, Bouachanh; Mairiang, Pisaln; Yamaoka, Yoshio; Shiota, Seiji; Binh, Tran Thanh; Mahachai, Varocha

2014-01-01

Helicobacter pylori (H. pylori) infection is an established cause of peptic ulcers and gastric cancer. The aim of this study was to identify H. pylori genotypes and to examine their associations with geographical regions and gastritis, peptic ulcers and gastric cancer in Laos. A total of 329 Lao dyspeptic patients who underwent gastroscopy at Mahosot Hospital, Vientiane, Laos during December 2010--March 2012 were enrolled. Two biopsy specimens (one each from the antrum and corpus) were obtained for CLO testing and only CLO test-positive gastric tissue were used to extract DNA. PCR and sequencing were identified for variants of the cagA and vacA genotypes. Some 119 Laos patients (36.2%) were found to be infected with H. pylori including 83 with gastritis, 13 with gastric ulcers (GU), 20 with duodenal ulcers (DU) and 3 with gastric cancer. cagA was detected in 99.2%. East-Asian-type cagA (62%) and vacA s1c (64.7%) were predominant genotypes in Laos. vacA s1c-m1b was significantly higher in GU than gastritis (53.8% vs. 24.1%; P-value=0.04) whereas vacA s1a-m2 was significantly higher in DU than gastritis (40.0% vs. 16.9%; P-value=0.03). East-Asian-type cagA and vacA s1c were significantly higher in highland than lowland Lao (100% vs. 55.8%; P-value=0.001 and 88.2% vs. 61.5%, P-value=0.03 respectively). H. pylori is a common infection in Laos, as in other countries in Southeast Asia. The cagA gene was demonstrated in nearly all Laos patients, cagA and vacA genotypes being possible important factors in explaining H. pylori infection and disease outcomes in Laos.

Helicobacter pylori and gastroduodenal pathology: New threats of the old friend

Directory of Open Access Journals (Sweden)

Sechi Leonardo A

2005-01-01

Full Text Available Abstract The human gastric pathogen Helicobacter pylori causes chronic gastritis, peptic ulcer disease, gastric carcinoma, and mucosa-associated lymphoid tissue (MALT lymphoma. It infects over 50% of the worlds' population, however, only a small subset of infected people experience H. pylori-associated illnesses. Associations with disease-specific factors remain enigmatic years after the genome sequences were deciphered. Infection with strains of Helicobacter pylori that carry the cytotoxin-associated antigen A (cagA gene is associated with gastric carcinoma. Recent studies revealed mechanisms through which the cagA protein triggers oncopathogenic activities. Other candidate genes such as some members of the so-called plasticity region cluster are also implicated to be associated with carcinoma of stomach. Study of the evolution of polymorphisms and sequence variation in H. pylori populations on a global basis has provided a window into the history of human population migration and co-evolution of this pathogen with its host. Possible symbiotic relationships were debated since the discovery of this pathogen. The debate has been further intensified as some studies have posed the possibility that H. pylori infection may be beneficial in some humans. This assumption is based on increased incidence of gastro-oesophageal reflux disease (GERD, Barrett's oesophagus and adenocarcinoma of the oesophagus following H. pylori eradication in some countries. The contribution of comparative genomics to our understanding of the genome organisation and diversity of H. pylori and its pathophysiological importance to human healthcare is exemplified in this review.

Anti-CagA positivity in duodenal ulcer and functional dyspepsia patients infected with Helicobacter pylori and its effect on the outcome of eradication treatment

Directory of Open Access Journals (Sweden)

Yaşar Nazlıgül

2011-03-01

Full Text Available Objectives: CagA positive H. pylori strains are considered to be more virulent than other strains. In this study, we aimed to investigate the rate of CagA positivity in duodenal ulcer (DU and functional dyspepsia (FD, and its effect on H. pylori eradication response.Materials and methods: The study was performed on H. pylori positive 60 patients with DU and 50 patients with FD, who underwent upper gastrointestinal endoscopy. H. pylori infection was identified by histology. All patients received a quadriple therapy consisted of esomeprazole 20 mg b.i.d., colloidal bismuth subcitrate 600 mg b.i.d., tetracycline 500 mg q.i.d. and metronidazole 500 mg t.i.d. for 7 days. H.pylori status was rechecked using C14-urea breath test 6 weeks after the end of treatment to confirm cure. Specific IgG antibodies for CagA status were determined by enzyme linked immunosorbent assay.Results: CagA positivities in the patients with DU and FD were calculated respectivily 70% and 68% (P>0.05. H. pylori was eradicated in 85.5% of the patients infected with CagA (+ strains, in 50% of those infected with CagA (- strains (P=0.001. The eradication rates were 95.2% and 55.6% in CagA positive and negative DU subgroups (P=0.001, and 73.5% and 43.8% in CagA positive and negative FD subgroups (P=0.04.Conclusion: CagA positivities were not different in duodenal ulcer and functional dyspepsia. CagA (+ strains was susceptible to the eradication treatment. The titres of serum anti-CagA antibodies may be used in the prediction of eradication outcome, and the modification of eradication therapy.

Signal transduction of Helicobacter pylori during interaction with host cell protein receptors of epithelial and immune cells

Science.gov (United States)

Pachathundikandi, Suneesh Kumar; Tegtmeyer, Nicole; Backert, Steffen

2013-01-01

Helicobacter pylori infections can induce pathologies ranging from chronic gastritis, peptic ulceration to gastric cancer. Bacterial isolates harbor numerous well-known adhesins, vacuolating cytotoxin VacA, protease HtrA, urease, peptidoglycan, and type IV secretion systems (T4SS). It appears that H. pylori targets more than 40 known host protein receptors on epithelial or immune cells. A series of T4SS components such as CagL, CagI, CagY, and CagA can bind to the integrin α5β1 receptor. Other targeted membrane-based receptors include the integrins αvβ3, αvβ5, and β2 (CD18), RPTP-α/β, GP130, E-cadherin, fibronectin, laminin, CD46, CD74, ICAM1/LFA1, T-cell receptor, Toll-like receptors, and receptor tyrosine kinases EGFR, ErbB2, ErbB3, and c-Met. In addition, H. pylori is able to activate the intracellular receptors NOD1, NOD2, and NLRP3 with important roles in innate immunity. Here we review the interplay of various bacterial factors with host protein receptors. The contribution of these interactions to signal transduction and pathogenesis is discussed. PMID:24280762

Helicobacter pylori: focus on CagA and VacA major virulence factors Helicobacter pylori: enfoque sobre los factores de virulencia CagA y VacA

Directory of Open Access Journals (Sweden)

Gonzalo Castillo-Rojas

2004-12-01

Full Text Available After colonizing the human gastric mucosa, Helicobacter pylori can remain within the host for years and even decades, and is associated with several, highly significant gastric pathologies. In Mexico, the seroprevalence at 1 year of age is 20% and the estimated increment in seropositivity per year is 5% for children aged 1-10 years. More than 80% of adults are infected by the time they are 18-20 years old. Bacterial virulence factors have been proposed for H. pylori, such as urease, flagella, heat-shock protein, lipopolysaccharide, adhesions, vacuolating cytotoxin, cag pathogenicity island and the cytotoxin-associated protein, the latter being the most studied mechanism to date.Después de colonizar la mucosa gástrica humana, Helicobacter pylori puede permanecer por años e incluso décadas en el humano, y se asocia a varias patologías gástricas. En México, la seroprevalencia estimada es de 20% en niños de un año de edad, con una tasa de incremento en seropositividad de 5% anual durante los primeros 10 años de vida hasta alcanzar 80% en adultos jóvenes entre los 18 y 20 años de edad. Los factores bacterianos de virulencia propuestos para H. pylori son ureasa, flagelos, proteínas de choque térmico, lipopolisacárido, adhesinas, citotoxina vacuolizante, isla de patogenicidad y la proteína asociada a la citoxina; este último factor es el más estudiado hasta la fecha.

CD44 plays a functional role in Helicobacter pylori-induced epithelial cell proliferation.

Directory of Open Access Journals (Sweden)

Nina Bertaux-Skeirik

2015-02-01

Full Text Available The cytotoxin-associated gene (Cag pathogenicity island is a strain-specific constituent of Helicobacter pylori (H. pylori that augments cancer risk. CagA translocates into the cytoplasm where it stimulates cell signaling through the interaction with tyrosine kinase c-Met receptor, leading cellular proliferation. Identified as a potential gastric stem cell marker, cluster-of-differentiation (CD CD44 also acts as a co-receptor for c-Met, but whether it plays a functional role in H. pylori-induced epithelial proliferation is unknown. We tested the hypothesis that CD44 plays a functional role in H. pylori-induced epithelial cell proliferation. To assay changes in gastric epithelial cell proliferation in relation to the direct interaction with H. pylori, human- and mouse-derived gastric organoids were infected with the G27 H. pylori strain or a mutant G27 strain bearing cagA deletion (∆CagA::cat. Epithelial proliferation was quantified by EdU immunostaining. Phosphorylation of c-Met was analyzed by immunoprecipitation followed by Western blot analysis for expression of CD44 and CagA. H. pylori infection of both mouse- and human-derived gastric organoids induced epithelial proliferation that correlated with c-Met phosphorylation. CagA and CD44 co-immunoprecipitated with phosphorylated c-Met. The formation of this complex did not occur in organoids infected with ∆CagA::cat. Epithelial proliferation in response to H. pylori infection was lost in infected organoids derived from CD44-deficient mouse stomachs. Human-derived fundic gastric organoids exhibited an induction in proliferation when infected with H. pylori that was not seen in organoids pre-treated with a peptide inhibitor specific to CD44. In the well-established Mongolian gerbil model of gastric cancer, animals treated with CD44 peptide inhibitor Pep1, resulted in the inhibition of H. pylori-induced proliferation and associated atrophic gastritis. The current study reports a unique

[Helicobacter pylori population characteristic in patients with diseases of gastrointestinal tract].

Science.gov (United States)

Zhebrun, A B; Svarval', A V; Balabash, O A; Ferman, R S

2013-01-01

Study H. pylori strains circulating in St. Petersburg among patients with various gastrointestinal tract pathology as well as study of frequency of infection by H. pylori based on serological markers data among this group of patients. By using serological method 162 individuals with various chronic diseases of stomach and duodenum were examined. The presence in blood serum of IgG against H. pylori bacterial antigen and IgG against its toxin--CagA was studied. 129 patients were examined bacteriologically, biopsy samples of stomach mucous membrane were studied. PCR in real time format was used for study of H. pylori strains (49) and biopsy samples (36) of stomach mucous membrane. The analysis performed showed that on the territory of St. Petersburg H. pylori strains containing cagA gene predominate (81.63% of the isolated strains). Genotyping of strains by vacA showed that s1m1 genotype was more frequent (in 57.14% of cases). The fraction of CagA positive strains in patients in St. Petersburg is maximum for stomach cancer (90.8%), whereas for peptic ulcer disease and gastritis it is 64.7% and 72.2%, respectively. In patients with stomach and duodenum pathology the parameters of seropositivity for H. pylori were significantly higher than in individuals without clinical manifestations of H. pylori infection (86.72% against 65.09%; p < 0.05). The data obtained on increase of fraction of CagA positive strains among H. pylori circulating in St. Petersburg determine the importance of conducting eradication H. pylori.

Helicobacter pylori Outer Membrane Protein 18 (Hp1125 Is Involved in Persistent Colonization by Evading Interferon-γ Signaling

Directory of Open Access Journals (Sweden)

Yuqun Shan

2015-01-01

Full Text Available Outer membrane proteins (OMPs can induce an immune response. Omp18 (HP1125 of H. pylori is a powerful antigen that can induce significant interferon-γ (IFN-γ levels. Previous studies have suggested that IFN-γ plays an important role in H. pylori clearance. However, H. pylori has multiple mechanisms to avoid host immune surveillance for persistent colonization. We generated an omp18 mutant (H. pylori 26695 and H. pylori SS1 strain to examine whether Omp18 interacts with IFN-γ and is involved in H. pylori colonization. qRT-PCR revealed that IFN-γ induced Omp18 expression. qRT-PCR and western blot analysis revealed reduced expressions of virulence factors CagA and NapA in H. pylori 26695 with IFN-γ treatment, but they were induced in the Δomp18 strain. In C57BL/6 mice infected with H. pylori SS1 and the Δomp18 strain, the Δomp18 strain conferred defective colonization and activated a stronger inflammatory response. Signal transducer phosphorylation and transcription 1 (STAT1 activator was downregulated by the wild-type strain but not the Δomp18 strain in IFN-γ-treated macrophages. Furthermore, Δomp18 strain survival rates were poor in macrophages compared to the wild-type strain. We concluded that H. pylori Omp18 has an important function influencing IFN-γ-mediated immune response to participate in persistent colonization.

The Human Antimicrobial Protein Calgranulin C Participates in Control of Helicobacter pylori Growth and Regulation of Virulence.

Science.gov (United States)

Haley, Kathryn P; Delgado, Alberto G; Piazuelo, M Blanca; Mortensen, Brittany L; Correa, Pelayo; Damo, Steven M; Chazin, Walter J; Skaar, Eric P; Gaddy, Jennifer A

2015-07-01

During infectious processes, antimicrobial proteins are produced by both epithelial cells and innate immune cells. Some of these antimicrobial molecules function by targeting transition metals and sequestering these metals in a process referred to as "nutritional immunity." This chelation strategy ultimately starves invading pathogens, limiting their growth within the vertebrate host. Recent evidence suggests that these metal-binding antimicrobial molecules have the capacity to affect bacterial virulence, including toxin secretion systems. Our previous work showed that the S100A8/S100A9 heterodimer (calprotectin, or calgranulin A/B) binds zinc and represses the elaboration of the H. pylori cag type IV secretion system (T4SS). However, there are several other S100 proteins that are produced in response to infection. We hypothesized that the zinc-binding protein S100A12 (calgranulin C) is induced in response to H. pylori infection and also plays a role in controlling H. pylori growth and virulence. To test this, we analyzed gastric biopsy specimens from H. pylori-positive and -negative patients for S100A12 expression. These assays showed that S100A12 is induced in response to H. pylori infection and inhibits bacterial growth and viability in vitro by binding nutrient zinc. Furthermore, the data establish that the zinc-binding activity of the S100A12 protein represses the activity of the cag T4SS, as evidenced by the gastric cell "hummingbird" phenotype, interleukin 8 (IL-8) secretion, and CagA translocation assays. In addition, high-resolution field emission gun scanning electron microscopy (FEG-SEM) was used to demonstrate that S100A12 represses biogenesis of the cag T4SS. Together with our previous work, these data reveal that multiple S100 proteins can repress the elaboration of an oncogenic bacterial surface organelle. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Helicobacter pylori genotyping from positive clotests in patients with duodenal ulcer

Directory of Open Access Journals (Sweden)

Mattar Rejane

2000-01-01

Full Text Available Even though the seroprevalence of H. pylori may be high in the normal population, a minority develops peptic ulcer. Colonization of the gastric mucosa by more pathogenic vacA strains of H. pylori seems to be associated with enhanced gastric inflammation and duodenal ulcer. H. pylori genotyping from positive CLOtests was developed to determine the vacA genotypes and cagA status in 40 duodenal ulcer patients and for routine use. The pathogenic s1b/ m1/ cagA genotype was the most frequently occurring strain (17/42.5%; only two (5% patients presented the s2/ m2 genotype, the less virulent strain. Multiple strains were also detected in 17 (42.5% patients. Multiple strains of H. pylori colonizing the human stomach have been underestimated, because genotyping has been performed from cultures of H. pylori. We concluded that genotyping of H. pylori from a positive CLOtest had the advantages of reducing the number of biopsies taken during endoscopy, eliminating the step of culturing H. pylori, and assuring the presence of H. pylori in the specimen being processed.

Immune Responses to "Helicobacter pylori" Infection in Children with Intellectual Disabilities

Science.gov (United States)

Douraghi, Masoumeh; Goudarzi, Hossein; Rostami, Mahmoud Nateghi; Nikmanesh, Bahram

2012-01-01

Infection with "Helicobacter pylori" was assessed through serum "H. pylori" IgG antibody in children with intellectual disabilities (ID). The sero-status of cytotoxin-associated gene A (CagA) was determined as a risk determinant for severe "H. pylori"-associated diseases. In total, 210 children with ID were included…

Characteristics of clinical Helicobacter pylori strains from Ecuador.

Science.gov (United States)

Debets-Ossenkopp, Yvette J; Reyes, Germán; Mulder, Janet; aan de Stegge, Birgit M; Peters, José T A M; Savelkoul, Paul H M; Tanca, J; Peña, Amado S; Vandenbroucke-Grauls, Christina M J E

2003-01-01

In Ecuador, Helicobacter pylori infections are highly prevalent. A total of 42 H. pylori clinical isolates from 86 patients attending the outpatient clinic of the gastroenterology department of the university hospital of Guayaquil in Ecuador were characterized. Their susceptibility, and cagA and vacA status were determined. Resistance to metronidazole and clarithromycin was found in 80.9% and 9.5% of strains, respectively. Neither amoxicillin- nor tetracycline-resistant strains were found. The most prevalent genotype was the cagA(+), vacA s1b,m1 type. This genotype was associated with gastric cancer and peptic ulcer. Typing by random amplified polymorphic DNA showed no genetic relationship among the strains.

Distribution of Helicobacter pylori virulence markers in patients with gastroduodenal diseases in a region at high risk of gastric cancer.

Science.gov (United States)

Wang, Ming-yi; Chen, Cheng; Gao, Xiao-zhong; Li, Jie; Yue, Jing; Ling, Feng; Wang, Xiao-chun; Shao, Shi-he

2013-01-01

Helicobacter pylori (H. pylori) is a major human pathogen that is responsible for various gastroduodenal diseases. We investigated the prevalence of H. pylori virulence markers in a region at high risk of gastric cancer. One hundred and sixteen H. pylori strains were isolated from patients with gastroduodenal diseases. cagA, the cagA 3' variable region, cagPAI genes, vacA, and dupA genotypes were determined by PCR, and some amplicons of the cagA 3' variable region, cagPAI genes and dupA were sequenced. cagA was detected in all strains. The cagA 3' variable region of 85 strains (73.3%) was amplified, and the sequences of 24 strains were obtained including 22 strains possessing the East Asian-type. The partial cagPAI presented at a higher frequency in chronic gastritis (44.4%) than that of the severe clinical outcomes (9.7%, p dupA and sequencing of dupA revealed an ORF of 2449-bp. The prevalence of dupA was significantly higher in strains from patients with the severe clinical outcomes (40.3%) than that from chronic gastritis (20.4%, p = 0.02). The high rate of East Asian-type cagA, intact cagPAI, virulent vacA genotypes, and the intact long-type dupA may underlie the high risk of gastric cancer in the region. Copyright © 2013 Elsevier Ltd. All rights reserved.

Assessment of Risk and Sero-Prevalence of Helicobacter pylori Colonization among Remote Orang Asli Tribes in Peninsula Malaysia

Science.gov (United States)

Thevakumar, Kavitha; Chandren, Josephine Rebecca; Perez-Perez, Guillermo Ignacio; Chua, Eng Guan; Teh, Lay Kek; Salleh, Mohd Zaki; Tan, Jin Ai Mary Anne; Leow, Alex Hwong Ruey; Goh, Khean Lee; Tay, Alfred Chin Yen; Marshall, Barry J.; Vadivelu, Jamuna; Loke, Mun Fai; Wong, Li Ping

2016-01-01

The epidemiology of Helicobacter pylori (H. pylori) infection is related to human poverty with marked differences between developing and developed countries. Socioeconomic factors and living standards are the main determinants of the age-dependent acquisition rate of H. pylori, and consequently its prevalence. The aim of this study was to assess the risk and sero-prevalence of H. pylori colonization among Orang Asli in Peninsula Malaysia. This cross-sectional study was conducted on Orang Asli subjects in seven isolated settlements spanning across all three major tribes (Negrito, Proto Malay and Senoi) in Malaysia. Socio-demographic characteristics of the subjects were obtained through interview. Subjects were tested for H. pylori colonization based on CagA and whole cell (WC) antigen serological assays. A total of 275 subjects participated in this study. Among these subjects, 115 (44.7%) were H. pylori sero-positive with highest sero-prevalence among Negrito (65.7%). Among subjects who were H. pylori sero-positive, CagA sero positivity was also significantly higher among Negrito. The highest proportion of respondents reported to be H. pylori sero-positive was from age group 30 years old and below (57.9%), males (56.2%), Negrito (48.6%) and live in bamboo house (92.3%). The highest proportion of respondents reported to be CagA sero-positive was from age group 30 years old and below (41.4%), males (35.6%) and Negrito (48.6%). The results of this study demonstrate that H. pylori colonization can be related to age, gender, tribes and house materials and CagA sero-positive stain closely associated with age, gender and tribes. PMID:27441568

Impact of Helicobacter pylori on the healing process of the gastric barrier

Science.gov (United States)

Mnich, Eliza; Kowalewicz-Kulbat, Magdalena; Sicińska, Paulina; Hinc, Krzysztof; Obuchowski, Michał; Gajewski, Adrian; Moran, Anthony P; Chmiela, Magdalena

2016-01-01

AIM To determine the impact of selected well defined Helicobacter pylori (H. pylori) antigens on gastric barrier cell turnover. METHODS In this study, using two cellular models of gastric epithelial cells and fibroblasts, we have focused on exploring the effects of well defined H. pylori soluble components such as glycine acid extract antigenic complex (GE), subunit A of urease (UreA), cytotoxin associated gene A protein (CagA) and lipopolysaccharide (LPS) on cell turnover by comparing the wound healing capacity of the cells in terms of their proliferative and metabolic activity as well as cell cycle distribution. Toxic effects of H. pylori components have been assessed in an association with damage to cell nuclei and inhibition of signal transducer and activator of transcription 3 (STAT3) phosphorylation. RESULTS We showed that H. pylori GE, CagA and UreA promoted regeneration of epithelial cells and fibroblasts, which is necessary for effective tissue healing. However, in vivo increased proliferative activity of these cells may constitute an increased risk of gastric neoplasia. In contrast, H. pylori LPS showed a dose-dependent influence on the process of wound healing. At a low concentration (1 ng/mL) H. pylori LPS accelerated of healing epithelial cells, which was linked to significantly enhanced cell proliferation and MTT reduction as well as lack of alterations in cell cycle and downregulation of epidermal growth factor (EGF) production as well as cell nuclei destruction. By comparison, H. pylori LPS at a high concentration (25 ng/mL) inhibited the process of wound repair, which was related to diminished proliferative activity of the cells, cell cycle arrest, destruction of cell nuclei and downregulation of the EGF/STAT3 signalling pathway. CONCLUSION In vivo H. pylori LPS driven effects might lead to the maintenance of chronic inflammatory response and pathological disorders on the level of the gastric mucosal barrier. PMID:27672275

Medicinal plant activity on Helicobacter pylori related diseases

OpenAIRE

Wang, Yuan-Chuen

2014-01-01

More than 50% of the world population is infected with Helicobacter pylori (H. pylori). The bacterium highly links to peptic ulcer diseases and duodenal ulcer, which was classified as a group I carcinogen in 1994 by the WHO. The pathogenesis of H. pylori is contributed by its virulence factors including urease, flagella, vacuolating cytotoxin A (VacA), cytotoxin-associated gene antigen (Cag A), and others. Of those virulence factors, VacA and CagA play the key roles. Infection with H. pylori ...

Differential effects of multiplicity of infection on Helicobacter pylori-induced signaling pathways and interleukin-8 gene transcription.

Science.gov (United States)

Ritter, Birgit; Kilian, Petra; Reboll, Marc Rene; Resch, Klaus; DiStefano, Johanna Kay; Frank, Ronald; Beil, Winfried; Nourbakhsh, Mahtab

2011-02-01

Interleukin-8 (IL-8) plays a central role in the pathogenesis of Helicobacter pylori infection. We used four different H. pylori strains isolated from patients with gastritis or duodenal ulcer disease to examine their differential effects on signaling pathways and IL-8 gene response in gastric epithelial cells. IL-8 mRNA level is elevated in response to high (100) multiplicity of infection (MOI) independent of cagA, vacA, and dupA gene characteristics. By lower MOIs (1 or 10), only cagA ( + ) strains significantly induce IL-8 gene expression. This is based on differential regulation of IL-8 promoter activity. Analysis of intracellular signaling pathways indicates that H. pylori clinical isolates induce IL-8 gene transcription through NF-κB p65, but by a MOI-dependent differential activation of MAPK pathways. Thus, the major virulence factors of H. pylori CagA, VacA, and DupA might play a minor role in the level of IL-8 gene response to a high bacterial load.

The relationship between helicobacter pylori infection and gastro-esophageal reflux disease.

Science.gov (United States)

Mahdi, Batool M

2011-03-01

Gastro-esophageal reflux disease is a common condition, affecting 25%-40% of the population. Increasing attention has been paid to the relationship between Helicobacter pylori infection and reflux esophagitis. The aim of this study was to investigate the association between CagA+ H. pylori and endoscopically proven gastro-esophageal reflux disease. The study group included 60 hospital patients with gastro-esophageal reflux disease between 2007 and 2009 as compared with 30 healthy patients from a control group that was age and sex matched. Helicobacter pylori CagA+ was identified by an immunological test (Immunochromatography test) (ACON, USA). Helicobacter pyloriCagA+ was present in 42/60 (70%) of the patients with gastro-esophageal reflux disease and in 11/30 (36.6%) patients in the control group (p=0.002). The Odds ratio = 0.8004 with 95% Confidence Interval = from 0.3188 to 2.0094. The relative risk=1.35 that indicates an association between Helicobacter pylori and disease. The presence of Helicobacter pylori is significantly increased in patients with gastro-esophageal reflux disease as compared with the control group.

STAT3 polymorphism and Helicobacter pylori CagA strains with higher number of EPIYA-C segments independently increase the risk of gastric cancer

International Nuclear Information System (INIS)

Rocha, Gifone A; Rocha, Andreia MC; Gomes, Adriana D; Faria, César LL Jr; Melo, Fabrício F; Batista, Sérgio A; Fernandes, Viviane C; Almeida, Nathálie BF; Teixeira, Kádima N; Brito, Kátia S; Queiroz, Dulciene Maria Magalhães

2015-01-01

Because to date there is no available study on STAT3 polymorphism and gastric cancer in Western populations and taking into account that Helicobacter pylori CagA EPIYA-C segment deregulates SHP-2/ERK-JAK/STAT3 pathways, we evaluated whether the two variables are independently associated with gastric cancer. We included 1048 subjects: H. pylori-positive patients with gastric carcinoma (n = 232) and with gastritis (n = 275) and 541 blood donors. Data were analyzed using logistic regression model. The rs744166 polymorphic G allele (p = 0.01; OR = 1.76; 95 % CI = 1.44-2.70), and CagA-positive (OR = 12.80; 95 % CI = 5.58-19.86) status were independently associated with gastric cancer in comparison with blood donors. The rs744166 polymorphism (p = 0.001; OR = 1.64; 95 % CI = 1.16-2.31) and infection with H. pylori CagA-positive strains possessing higher number of EPIYA-C segments (p = 0.001; OR = 2.28; 95 % CI = 1.41-3.68) were independently associated with gastric cancer in comparison with gastritis. The association was stronger when host and bacterium genotypes were combined (p < 0.001; OR = 3.01; 95 % CI = 2.29-3.98). When stimulated with LPS (lipopolysaccharide) or Pam3Cys, peripheral mononuclear cells of healthy carriers of the rs744166 GG and AG genotypes expressed higher levels of STAT3 mRNA than those carrying AA genotype (p = 0.04 for both). The nuclear expression of phosphorylated p-STAT3 protein was significantly higher in the antral gastric tissue of carriers of rs744166 GG genotype than in carriers of AG and AA genotypes. Our study provides evidence that STAT3 rs744166 G allele and infection with CagA-positive H. pylori with higher number of EPIYA-C segments are independent risk factors for gastric cancer. The odds ratio of having gastric cancer was greater when bacterium and host high risk genotypes were combined

Elevated interleukin-32 expression is associated with Helicobacter pylori-related gastritis.

Directory of Open Access Journals (Sweden)

Liu-Sheng Peng

Full Text Available BACKGROUND: Interleukin-32 (IL-32 is a recently discovered proinflammatory cytokine involved in inflammatory diseases. We investigated the expression of IL-32 and its regulation mechanism in the inflammatory response of patients with Helicobacter pylori (H. pylori infection. DESIGN AND METHODS: IL-32 mRNA and protein expression in gastric tissues was detected by quantitative real-time PCR and immunohistochemistry. The regulation of IL-32 in human gastric epithelia cell line AGS was investigated by different cytokine stimulation and different H. pylori strain infection. RESULTS: Gastric IL-32 mRNA and protein expression were elevated in patients with H. pylori infection and positively correlated with gastritis. In H. pylori-infected patients, the mRNA level of IL-32 was also correlated with that of proinflammatory cytokines IL-1β and TNF-α. In vitro IL-1β and TNF-α could upregulate IL-32 mRNA and protein level in AGS cells, which was dependent on NF-κB signal pathway. The regulation of IL-32 expression in response to H. pylori-infection could be weakened by using neutralizing antibodies to block IL-1β and TNF-α. Moreover, H. pylori-infected AGS cells also induced IL-32 mRNA and protein expression, which was dependent on CagA. CONCLUSIONS: IL-32 level is elevated in patients with H. pylori infection and its expression is regulated by proinflammatory stimuli, suggesting that IL-32 may play a role in the pathogenesis of H. pylori-related gastritis.

Molecular Epidemiology of Helicobacter pylori Infection in a Minor Ethnic Group of Vietnam: A Multiethnic, Population-Based Study.

Science.gov (United States)

Binh, Tran Thanh; Tuan, Vo Phuoc; Dung, Ho Dang Quy; Tung, Pham Huu; Tri, Tran Dinh; Thuan, Ngo Phuong Minh; Tam, Le Quang; Nam, Bui Chi; Giang, Do Anh; Hoan, Phan Quoc; Uchida, Tomohisa; Trang, Tran Thi Huyen; Khien, Vu Van; Yamaoka, Yoshio

2018-03-01

The Helicobacter pylori -induced burden of gastric cancer varies based on geographical regions and ethnic grouping. Vietnam is a multiethnic country with the highest incidence of gastric cancer in Southeast Asia, but previous studies focused only on the Kinh ethnic group. A population-based cross-sectional study was conducted using 494 volunteers (18-78 years old), from 13 ethnic groups in Daklak and Lao Cai provinces, Vietnam. H. pylori status was determined by multiple tests (rapid urease test, culture, histology, and serology). cagA and vacA genotypes were determined by PCR-based sequencing. The overall H. pylori infection rate was 38.1%. Multivariate analysis showed that variations in geographical region, age, and ethnicity were independent factors associated with the risk of H. pylori acquisition. Therefore, multicenter, multiethnic, population based study is essential to assess the H. pylori prevalence and its burden in the general population. Only the E De ethnicity carried strains with Western-type CagA (82%) and exhibited significantly lower gastric mucosal inflammation compared to other ethnic groups. However, the histological scores of Western-type CagA and East-Asian-type CagA within the E De group showed no significant differences. Thus, in addition to bacterial virulence factors, host factors are likely to be important determinants for gastric mucosal inflammation and contribute to the Asian enigma.

ROLE OF HELICOBACTER PYLORI INFECTION AND LIFESTYLE HABITS IN THE DEVELOPMENT OF GASTRODUODENAL DISEASES IN A POPULATION FROM THE BRAZILIAN AMAZON

Directory of Open Access Journals (Sweden)

Ruth Maria Dias Ferreira VINAGRE

2013-09-01

Full Text Available Context Although more than half of the world's population is colonized with Helicobacter pylori, it remains unknown why this organism is able to produce severe disease in some hosts and be innocuous in others. The clinical outcome of infection is determined by several factors, including differences in the host response to bacterial stimulation, specific virulence factors of the organism and environmental influences, or a combination of these factors. Objectives This study compared the prevalence of H. pylori infection and risk factors (infection with CagA+ strains, excessive alcohol consumption, smoking, and inadequate eating habits between patients with different gastrointestinal disorders and associated these risk factors with the histopathological findings. Methods In a prospective study, samples were collected from 442 patients and a standardized questionnaire regarding lifestyle habits (excessive alcohol consumption, smoking, and eating habits was applied. The presence of H. pylori and of the cagA gene was investigated by polymerase chain reaction (PCR. Gastric biopsies were obtained for histological assessment. Results The frequency of alcohol consumption, smoking, inadequate diet and infection with CagA+ H. pylori was higher among patients with peptic ulcer and adenocarcinoma when compared to those with gastritis. Gastric inflammation was more pronounced in patients infected with CagA+ strains. Conclusion We conclude that infection with CagA+ H. pylori strains, excessive alcohol consumption, smoking and inadequate eating habits increase the risk of developing peptic ulcer and gastric carcinoma.

Analysis of T4SS-induced signaling by H. pylori using quantitative phosphoproteomics

Directory of Open Access Journals (Sweden)

Frithjof eGlowinski

2014-07-01

Full Text Available Helicobacter pylori is a Gram-negative bacterial pathogen colonizing the human stomach. Infection with H. pylori causes chronic inflammation of the gastric mucosa and may lead to peptic ulceration and/or gastric cancer. A major virulence determinant of H. pylori is the type IV secretion system (T4SS, which is used to inject the virulence factor CagA into the host cell, triggering a wide range of cellular signaling events. Here, we used a phosphoproteomic approach to investigate tyrosine signaling in response to host-pathogen interaction, using stable isotope labeling in cell culture (SILAC of AGS cells to obtain a differential picture between multiple infection conditions. Cells were infected with wild type H. pylori P12, a P12ΔCagA deletion mutant, and a P12ΔT4SS deletion mutant to compare signaling changes over time and in the absence of CagA or the T4SS. Tryptic peptides were enriched for tyrosine (Tyr phosphopeptides and analysed by nano-LC-Orbitrap MS. In total, 58 different phosphosites were found to be regulated following infection. The majority of phosphosites identified were kinases of the MAPK familiy. CagA and the T4SS were found to be key regulators of Tyr phosphosites. Our findings indicate that CagA primarily induces activation of ERK1 and integrin linked factors, whereas the T4SS primarily modulates JNK and p38 activation.

Association between infection with Helicobacter pylori and atopy in young Ethiopian children: A longitudinal study.

Science.gov (United States)

Taye, B; Enquselassie, F; Tsegaye, A; Amberbir, A; Medhin, G; Fogarty, A; Robinson, K; Davey, G

2017-10-01

Epidemiological evidence from developed countries indicates that Helicobacter pylori infection correlates with a reduced risk of atopy and allergic disorders; however, limited data are available from low-income countries. We examined associations between H. pylori infection in early childhood and atopy and reported allergic disorders at the age of 6.5 years in an Ethiopian birth cohort. A total of 856 children (85.1% of the 1006 original singletons in a population-based birth cohort) were followed up at age six and half years. An interviewer-led questionnaire administered to mothers provided information on demographic and lifestyle variables. Questions on allergic disease symptoms were based on the International Study of Asthma and Allergies in Children (ISAAC) core allergy and environmental questionnaire. Serum samples were analysed for total IgE levels and anti-H. pylori cytotoxin-associated gene A (CagA) IgG antibody using commercially available ELISA kits. Stool samples were analysed for H. pylori antigen using a rapid immunochromatographic test. The independent effects of H. pylori infection (measured at age of 3, 5 and 6.5 years) on prevalence and incidence of atopy and reported allergic disorders (measured at age of 6.5 years) were determined using multiple logistic regression. In cross-sectional analysis, current H. pylori infection at age 6.5 years was inversely, though not significantly, related to prevalence of atopy and "any allergic condition" at age 6.5 years. However, detection of H. pylori infection at any point up to age 6.5 years was associated with a significantly reduced odds of both atopy and "any allergic condition" (adjusted OR AOR, 95% CI, 0.54; 0.32-0.92, P = .02, and .31; 0.10-0.94, P = .04, respectively). In longitudinal analyses, H. pylori infection at age 3 was inversely associated with incidence of atopy (AOR, 95% CI, 0.49; 0.27-0.89, P = .02). Furthermore, among H. pylori-infected children, those with a CagA

Validation of a Novel Immunoline Assay for Patient Stratification according to Virulence of the Infecting Helicobacter pylori Strain and Eradication Status

Directory of Open Access Journals (Sweden)

Luca Formichella

2017-01-01

Full Text Available Helicobacter pylori infection shows a worldwide prevalence of around 50%. However, only a minority of infected individuals develop clinical symptoms or diseases. The presence of H. pylori virulence factors, such as CagA and VacA, has been associated with disease development, but assessment of virulence factor presence requires gastric biopsies. Here, we evaluate the H. pylori recomLine test for risk stratification of infected patients by comparing the test score and immune recognition of type I or type II strains defined by the virulence factors CagA, VacA, GroEL, UreA, HcpC, and gGT with patient’s disease status according to histology. Moreover, the immune responses of eradicated individuals from two different populations were analysed. Their immune response frequencies and intensities against all antigens except CagA declined below the detection limit. CagA was particularly long lasting in both independent populations. An isolated CagA band often represents past eradication with a likelihood of 88.7%. In addition, a high recomLine score was significantly associated with high-grade gastritis, atrophy, intestinal metaplasia, and gastric cancer. Thus, the recomLine is a sensitive and specific noninvasive test for detecting serum responses against H. pylori in actively infected and eradicated individuals. Moreover, it allows stratifying patients according to their disease state.

Pathogenesis of Helicobacter pylori-Related Gastroduodenal Diseases from Molecular Epidemiological Studies.

Science.gov (United States)

Yamaoka, Yoshio

2012-01-01

Helicobacter pylori is a major human pathogen that infects the stomach and produces inflammation that is responsible for various gastroduodenal diseases. Despite the high prevalence of H. pylori infections in Africa and South Asia, the incidence of gastric cancer in these areas is much lower than in other countries. The incidence of gastric cancer also tends to decrease from north to south in East Asia. Data from molecular epidemiological studies show that this variation in different geographic areas could be explained in part by different types of H. pylori virulence factors, especially CagA, VacA, and OipA. H. pylori infection is thought to be involved in both gastric cancer and duodenal ulcer, which are at opposite ends of the disease spectrum. This discrepancy can also be explained in part by another H. pylori factor, DupA, as well as by CagA typing (East Asian type versus Western type). H. pylori has a genome of approximately 1,600 genes; therefore, there might be other novel virulence factors. Because genome wide analyses using whole-genome sequencing technology give a broad view of the genome of H. pylori, we hope that next-generation sequencers will enable us to efficiently investigate novel virulence factors.

Pathogenesis of Helicobacter pylori-Related Gastroduodenal Diseases from Molecular Epidemiological Studies

Directory of Open Access Journals (Sweden)

Yoshio Yamaoka

2012-01-01

Full Text Available Helicobacter pylori is a major human pathogen that infects the stomach and produces inflammation that is responsible for various gastroduodenal diseases. Despite the high prevalence of H. pylori infections in Africa and South Asia, the incidence of gastric cancer in these areas is much lower than in other countries. The incidence of gastric cancer also tends to decrease from north to south in East Asia. Data from molecular epidemiological studies show that this variation in different geographic areas could be explained in part by different types of H. pylori virulence factors, especially CagA, VacA, and OipA. H. pylori infection is thought to be involved in both gastric cancer and duodenal ulcer, which are at opposite ends of the disease spectrum. This discrepancy can also be explained in part by another H. pylori factor, DupA, as well as by CagA typing (East Asian type versus Western type. H. pylori has a genome of approximately 1,600 genes; therefore, there might be other novel virulence factors. Because genome wide analyses using whole-genome sequencing technology give a broad view of the genome of H. pylori, we hope that next-generation sequencers will enable us to efficiently investigate novel virulence factors.

Serological response to Helicobacter pylori infection among Latin American populations with contrasting risks of gastric cancer

Science.gov (United States)

Camargo, M. Constanza; Beltran, Mauricio; Conde-Glez, Carlos; Harris, Paul R.; Michel, Angelika; Waterboer, Tim; Flórez, Astrid Carolina; Torres, Javier; Ferreccio, Catterina; Sampson, Joshua N.; Pawlita, Michael; Rabkin, Charles S.

2015-01-01

Gastric cancer is a rare outcome of chronic Helicobacter pylori infection. Serologic profiles may reveal bacterial, environmental and/or host factors associated with cancer risk. We therefore compared specific anti-H. pylori antibodies among populations with at least 2-fold differences in gastric cancer mortality from Mexico, Colombia and Chile. Our study included 1,776 adults (mean age 42 years) from three nationally representative surveys, equally divided between residents of high- and low-risk areas. Antibodies to 15 immunogenic H. pylori antigens were measured by fluorescent bead-based multiplex assays; results were summarized to identify overall H. pylori seropositivity. We used logistic regression to model associations between antibody seroreactivity and regional cancer risk (high vs. low), adjusting for country, age and sex. Both risk areas had similar H. pylori seroprevalence. Residents in high- and low-risk areas were seroreactive to a similar number of antigens (means 8.2 vs. 7.9, respectively; adjusted-odds ratio, OR: 1.02, p=0.05). Seroreactivities to Catalase and the known virulence proteins CagA and VacA were each significantly (p<0.05) associated with residence in high-risk areas, but ORs were moderate (1.26, 1.42, and 1.41, respectively) and their discriminatory power was low (ROC area under curve <0.6). The association of Catalase was independent from effects of either CagA or VacA. Sensitivity analyses for antibody associations restricted to H. pylori-seropositive individuals generally replicated significant associations. Our findings suggest that humoral responses to H. pylori are insufficient to distinguish high and low gastric cancer risk in Latin America. Factors determining population variation of gastric cancer burden remain to be identified. PMID:26178251

Peptic Ulcer Disease and Helicobacter pylori Infection in Different Siberian Ethnicities.

Science.gov (United States)

Tsukanov, Vladislav V; Kasparov, Edward V; Tonkikh, Julia L; Shtygasheva, Olga V; Butorin, Nikolay N; Amelchugova, Olga S; Vasyutin, Alexander V; Bronnikova, Elena P; Fassan, Matteo; Rugge, Massimo

2017-02-01

The high prevalence of Helicobacter pylori (H. pylori) infection in eastern Siberia is consistently established. In the same geographic area, however, fragmentary information is available on the epidemiology of the peptic ulcer disease (PUD). To assess the prevalence of H. pylori infection (including CagA status) and PUD in different eastern Siberian ethnicities. An endoscopy population of 3149 eastern Siberian dyspeptic patients was considered [1727 Europoids and 1422 Mongoloids (Evenks = 792; Khakases = 630)]. H. pylori status was assessed by urease test and/or serum anti-H. pylori IgG and/or histology. CagA status was serologically assessed (anti-CagA antibodies). All the Siberian ethnicities featured high rates of H. pylori infection (Europoids = 87.1%, Evenks = 88.6%, Khakases = 85.4%). Among the 1504 H. pylori-positive Europoids, the prevalence of CagA-positive status (68.7%) was significantly higher than that featured by the 1240 H. pylori-positive Mongoloid ethnicities (46.9%; p Peptic ulcer disease significantly prevailed among Europoids (prevalence among Europoid Evenks and Khakases: 8.9% and 8.3%, respectively; prevalence among Mongoloid Evenks and Khakases = 1.0% and 4.4%, respectively). eastern Siberian populations feature consistent high rates of H. pylori infection, but different prevalence of peptic ulcer disease. In particular, Europoids featured a prevalence of both CagA-positive status and peptic ulcer disease significantly higher than that of the Mongoloid ethnicities. These results suggest that both environmental factors (coexisting with the H. pylori infection) and host-related variables modulate the clinicopathological expression of the H. pylori -associated gastric diseases. © 2016 John Wiley & Sons Ltd.

A Helicobacter pylori Homolog of Eukaryotic Flotillin Is Involved in Cholesterol Accumulation, Epithelial Cell Responses and Host Colonization

Directory of Open Access Journals (Sweden)

Melanie L. Hutton

2017-06-01

Full Text Available The human pathogen Helicobacter pylori acquires cholesterol from membrane raft domains in eukaryotic cells, commonly known as “lipid rafts.” Incorporation of this cholesterol into the H. pylori cell membrane allows the bacterium to avoid clearance by the host immune system and to resist the effects of antibiotics and antimicrobial peptides. The presence of cholesterol in H. pylori bacteria suggested that this pathogen may have cholesterol-enriched domains within its membrane. Consistent with this suggestion, we identified a hypothetical H. pylori protein (HP0248 with homology to the flotillin proteins normally found in the cholesterol-enriched domains of eukaryotic cells. As shown for eukaryotic flotillin proteins, HP0248 was detected in detergent-resistant membrane fractions of H. pylori. Importantly, H. pylori HP0248 mutants contained lower levels of cholesterol than wild-type bacteria (P < 0.01. HP0248 mutant bacteria also exhibited defects in type IV secretion functions, as indicated by reduced IL-8 responses and CagA translocation in epithelial cells (P < 0.05, and were less able to establish a chronic infection in mice than wild-type bacteria (P < 0.05. Thus, we have identified an H. pylori flotillin protein and shown its importance for bacterial virulence. Taken together, the data demonstrate important roles for H. pylori flotillin in host-pathogen interactions. We propose that H. pylori flotillin may be required for the organization of virulence proteins into membrane raft-like structures in this pathogen.

A study of RUNX3, E-cadherin and β-catenin in CagA-positive Helicobacter pylori associated chronic gastritis in Saudi patients.

Science.gov (United States)

Wagih, H M; El-Ageery, S M; Alghaithy, A A

2015-04-01

H. pylori is the most important risk factor for gastric carcinoma. CagA-positive H. pylori is associated with an increased risk for gastric cancer compared with negative strains. RUNX3 is a tumor suppressor gene, which is related to the genesis of gastric cancer. β-catenin is integrated with E-cadherin in the cell membrane, and aberrant expression of the complex was reported in gastric carcinoma. Aim of this paper is to determine of the relation between RUNX3, E-cadherin and β-catenin in chronic gastritis associated with cagA-positive H. pylori infection. Retrospective study was done on formalin fixed paraffin embedded gastric biopsies blocks of 90 patients diagnosed as H. pylori associated chronic gastritis. H. pylori was detected using modified Giemsa stain. Nested PCR was used for detection of cagA, reverse transcription-PCR for detection of RUNX3 and immunohistochemistry for detection of E-cadherin and β-catenin. Fifty percent of cases were found to be cagA positive. CagA was significantly associated with the intensity of mononuclear inflammation, the intensity of neutrophilic inflammation, the degree of mucosal atrophy and loss of RUNX3 but not with the density of H. pylori, intestinal metaplasia, E-cadherin or β-catenin. There was significant relation between loss of RUNX3 and increasing density of H. pylori, intensity of neutrophilic inflammation, mucosal atrophy and intestinal metaplasia. RUNX3 was found to be significantly correlated with E-cadherin but not with β-catenin. E-cadherin showed decreased expression in 36.7% of biopsies while, β-catenin was decreased in 33% of biopsies. Loss of RUNX3, E-cadherin and β-catenin was considered early events in the cascade of gastric carcinoma development. Loss of RUNX3 but neither E-cadherin nor β-catenin was related to cagA positive H. pylori strains.

Analysis of antimicrobial susceptibility and virulence factors in Helicobacter pylori clinical isolates

Directory of Open Access Journals (Sweden)

Mendonça Sergio

2003-08-01

Full Text Available Abstract Background In this study, we evaluated the prevalence of primary resistance of Brazilian H. pylori isolates to metronidazole, clarithromycin, amoxicillin, tetracycline, and furazolidone. In addition, the vacA, iceA, cagA and cagE genotypes of strains isolated from Brazilian patients were determined and associated with clinical data in an effort to correlate these four virulence markers and antibiotic resistance. Methods H. pylori was cultured in 155 H. pylori-positive patients and MICs for metronidazole, clarithromycin, amoxicillin, tetracycline, and furazolidone were determined by the agar dilution method. Genomic DNA was extracted, and allelic variants of vacA, iceA, cagA and cagE were identified by the polymerase chain reaction. Results There was a strong association between the vacA s1/cagA -positive genotype and peptic ulcer disease (OR = 5.42, 95% CI 2.6–11.3, p = 0.0006. Additionally, infection by more virulent strains may protect against GERD, since logistic regression showed a negative association between the more virulent strain, vacA s1/cagA-positive genotype and GERD (OR = 0.26, 95% CI 0.08–0.8, p = 0.03. Resistance to metronidazole was detected in 75 patients (55%, to amoxicillin in 54 individuals (38%, to clarithromycin in 23 patients (16%, to tetracycline in 13 patients (9%, and to furazolidone in 19 individuals (13%. No significant correlation between pathogenicity and resistance or susceptibility was detected when MIC values for each antibiotic were compared with different vacA, iceA, cagA and cagE genotypes. Conclusion The analysis of virulence genes revealed a specific association between H. pylori strains and clinical outcome, furthermore, no significant association was detected among pathogenicity and resistance or susceptibility.

Virulence factor genotypes of Helicobacter pylori affect cure rates of eradication therapy.

Science.gov (United States)

Sugimoto, Mitsushige; Yamaoka, Yoshio

2009-01-01

The cure rates of Helicobacter pylori infection by using a combination of a proton pump inhibitor (PPI) and antimicrobial agents are mainly influenced by bacterial susceptibility to antimicrobial agents and the magnitude of acid inhibition during the treatment. Currently used empirical triple therapies do not reliably produce a > or =80% cure rate on an intention-to-treat basis. Therefore, tailored regimens based on relevant microbiological findings and pharmacogenomics are recommended for attaining an acceptable > or =95% cure rate. Recently, virulence factors of H. pylori, such as cagA and vacA, are reported to be major factors determining the cure rates. Individuals infected with strains with cagA-negative and vacA s2 genotypes have significantly increased risk of eradication failure of H. pylori infection. These virulence factors enhance gastric mucosal inflammation and are associated with the development of peptic ulcer and gastric cancer. H. pylori virulence factors induce proinflammatory cytokines, such as interleukin (IL)-1, IL-8, and tumor necrosis factor (TNF)- which influence mucosal inflammation and/or gastric acid secretion. When physicians select an H. pylori eradication regimen with an acceptable cure rate, they might need to consider H. pylori virulence factors, especially cagA and vacA.

Association of the Helicobacter pylori cagA, vacA, and iceA genotypes with chronic follicular gastritis in a Colombian population at high risk for gastric cancer.

Science.gov (United States)

Carlosama-Rosero, Y H; Bolaños-Bravo, H; Sierra-Tórres, C H; Rosero, E A

2018-05-16

Follicular gastritis is associated with Helicobacter pylori infection, but little is known of its relation to bacterial genotypes. Our aim was to establish the relation between follicular gastritis and different H. pylori strains. An analytic case-control study was conducted that included 36 patients with follicular gastritis (cases) and 83 with nonatrophic gastritis (controls). The sociodemographic information was obtained through a questionnaire. Biopsies were evaluated according to the Sydney System and the Wotherspoon scoring system. Helicobacter pylori genotyping was performed using the polymerase chain reaction technique. The quantitative variables were presented as mean and standard deviation and the qualitative variables as proportions and absolute frequency. The effect of each variable on outcome (follicular gastritis) was evaluated through the odds ratio and its 95% confidence interval. Statistical significance was set at a P<.05. Follicular gastritis was associated with Helicobacter pylori infection (OR: 13.41, CI: 1.7-103, P=.01). The CagA+ genotype was present in 56.5% of the cases and 58% of the controls. The cytotoxic VacAs1m1strain was present in 82% of the isolates in both groups. IceA1 frequency was 34.8% in the cases and 26% in the controls and the difference was not statistically significant. The population studied had elevated frequencies of cytotoxic Helicobacter pylori strains and the iceA1 genotype was more frequent in follicular gastritis. Copyright © 2018 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.

Association of helicobacter pylori infection and chronic atrophic gastritis with risk of colonic, pancreatic and gastric cancer: A ten-year follow-up of the ESTHER cohort study.

Science.gov (United States)

Chen, Xin-Zu; Schöttker, Ben; Castro, Felipe Andres; Chen, Hongda; Zhang, Yan; Holleczek, Bernd; Brenner, Hermann

2016-03-29

To assess the association of H. pylori and chronic atrophic gastritis (AG) with colonic, pancreatic and gastric cancer in a population-based prospective cohort. Serum antibodies against H. pylori in general and specific to cytotoxin-associated gene A (CagA), as well as serum pepsinogen I and II were analyzed in 9,506 men and women, aged 50-75 years in a cohort study from Saarland, Germany. Incident cases of colonic, pancreatic and gastric cancer were ascertained by record linkage with data from the Saarland Cancer Registry. During an average follow-up of 10.6 years, 108 colonic, 46 pancreatic and 27 gastric incident cancers were recorded. There was no association between H. pylori infection and colonic cancer (HR = 1.07; 95% CI 0.73-1.56) or pancreatic cancer (HR = 1.32; 0.73-2.39), regardless of either CagA seropositivity or AG status. In contrast, CagA+ infection was associated with a strongly increased risk of gastric cancer, especially non-cardia gastric cancer, and this association was particularly pronounced in the presence of AG. Compared to people without AG and without CagA+ infection, people with both risk factors had a significantly increased risk of non-cardia gastric cancer (HR = 32.4; 7.6-137.6). This large cohort study did not observe an association of H. pylori infection or AG with colonic or pancreatic cancer, but underlines that the vast majority of non-cardia gastric cancers arise from AG and infection with CagA+ H. pylori strains.

Detection of Helicobacter pylori CagA and VacA genotypes from ...

African Journals Online (AJOL)

Background: Helicobacter pylori(H. Pylori) is one of the most common pathogens affecting human kind, infecting more than 50% of the world's population. Invasive and non- invasive methods have been used to diagnose H. pylori infection. The polymerase chain reaction (PCR) has been broadly and successfully used to ...

Interleukin 10 in Helicobacter pylori associated gastritis: immunohistochemical localisation and in vitro effects on cytokine secretion

Science.gov (United States)

Bodger, K; Bromelow, K; Wyatt, J; Heatley, R

2001-01-01

the surface epithelium in all H pylori positive cases and in 13 of 16 negative cases, especially in areas of surface epithelial degeneration. Lamina propria mononuclear cells (LPMNCs) were positively stained in all H pylori positive cases and in 12 of 16 negative cases, with a significantly greater proportion of positive LPMNCs in the positive group. Conclusions—This study localised IL-10 protein to the gastric epithelium and LPMNCs. In vitro proinflammatory cytokine secretion was increased in H pylori infection (especially CagA positive infection), but blocking endogenous IL-10 secretion did not significantly increase cytokine secretion. IL-10 is implicated in H pylori infection and might "damp down" local inflammation. The role of gastric IL-10 secretion in determining the clinicopathological outcome of infection merits further study. Key Words: Helicobacter pylori infection • interleukin 10 • gastritis • immunohistochemistry PMID:11304845

Helicobacter pylori virulence factors and their role in peptic ulcer diseases in Turkey.

Science.gov (United States)

Tuncel, I E; Hussein, N R; Bolek, B K; Arikan, S; Salih, B A

2010-01-01

The role of virulence factors present in Helicobacter pylori (H. pylori) strains and the characterization of such factors being predictive of specific disease is still not clear. In this study, the cagA, vacA alleles and the recently characterized vacA i-region and dupA and their association with the severity of the disease was determined. Antral biopsies from 91patients with peptic ulcer (PU) (n = 41), gastritis (n = 48) and gastric cancer (GC) (n = 2) were analyzed for the presence of H. pylori by the CLO-test and PCR. A 79/91 (86%) patients were positive for H. pylori by either PCR or by both PCR and CLO-test. PCR-based typing of H. pylori isolates was performed on DNA extracted directly from biopsy samples. The cagA+ strains were found more likely to be associated with vacA s1 than s2. The vacA i1 allele detected in 16/23 (70%) of samples had significant association with duodenal ulcers than those 16/37 (44%) of gastritis (P dupA and duodenal ulcer. This study provided more evidence that the vacA i1 allele is one of the virulence factors of H. pylori that had significant association with severe outcome.

Medicinal plant activity on Helicobacter pylori related diseases.

Science.gov (United States)

Wang, Yuan-Chuen

2014-08-14

More than 50% of the world population is infected with Helicobacter pylori (H. pylori). The bacterium highly links to peptic ulcer diseases and duodenal ulcer, which was classified as a group I carcinogen in 1994 by the WHO. The pathogenesis of H. pylori is contributed by its virulence factors including urease, flagella, vacuolating cytotoxin A (VacA), cytotoxin-associated gene antigen (Cag A), and others. Of those virulence factors, VacA and CagA play the key roles. Infection with H. pylori vacA-positive strains can lead to vacuolation and apoptosis, whereas infection with cagA-positive strains might result in severe gastric inflammation and gastric cancer. Numerous medicinal plants have been reported for their anti-H. pylori activity, and the relevant active compounds including polyphenols, flavonoids, quinones, coumarins, terpenoids, and alkaloids have been studied. The anti-H. pylori action mechanisms, including inhibition of enzymatic (urease, DNA gyrase, dihydrofolate reductase, N-acetyltransferase, and myeloperoxidase) and adhesive activities, high redox potential, and hydrophilic/hydrophobic natures of compounds, have also been discussed in detail. H. pylori-induced gastric inflammation may progress to superficial gastritis, atrophic gastritis, and finally gastric cancer. Many natural products have anti-H. pylori-induced inflammation activity and the relevant mechanisms include suppression of nuclear factor-κB and mitogen-activated protein kinase pathway activation and inhibition of oxidative stress. Anti-H. pylori induced gastric inflammatory effects of plant products, including quercetin, apigenin, carotenoids-rich algae, tea product, garlic extract, apple peel polyphenol, and finger-root extract, have been documented. In conclusion, many medicinal plant products possess anti-H. pylori activity as well as an anti-H. pylori-induced gastric inflammatory effect. Those plant products have showed great potential as pharmaceutical candidates for H. pylori

Helicobacter pylori infection in women with Hashimoto thyroiditis

Science.gov (United States)

Shmuely, Haim; Shimon, Ilan; Gitter, Limor Azulay

2016-01-01

Abstract An association between Helicobacter pylori (H pylori) infection as environmental risk factors for Hashimoto thyroiditis (HT) has been reported. We investigated this hypothesis in women in which HT is more common. Serum immunoglobulin G antibodies against H pylori (enzyme-linked immunosorbent assay), CagA protein (Western blot assay), circulating antibodies to thyroid antigens, mainly thyroperoxidase (TPOAbs) and thyroglobulin (TgAbs), were tested in 101 females with HT and 111 non-HT control women without a history of autoimmune disease. Thyroid function, socioeconomic status at childhood, and family history of thyroid malfunction were also studied. Forty-seven HT women (46.5%) tested seropositive for H pylori versus 48 controls (43.2%; P = 0.63). The prevalence of anti-CagA antibodies was 21.3% in HT-infected patients and 31.2% in infected controls (P = 0.352). Women with HT were older than the controls at a significance level of 0.03, and higher prevalence of hypothyroidism (69% vs 13.5%, respectively) and family history of thyroid malfunction (59% vs 34%, respectively) (P thyroid malfunction was independently associated with an increased risk of HT (odds ratio 3.39, 95% confidence interval 1.86–6.18, P thyroid malfunction is a risk factor for HT. PMID:27442635

Caveolin-1 protects B6129 mice against Helicobacter pylori gastritis.

Directory of Open Access Journals (Sweden)

Ivana Hitkova

Full Text Available Caveolin-1 (Cav1 is a scaffold protein and pathogen receptor in the mucosa of the gastrointestinal tract. Chronic infection of gastric epithelial cells by Helicobacter pylori (H. pylori is a major risk factor for human gastric cancer (GC where Cav1 is frequently down-regulated. However, the function of Cav1 in H. pylori infection and pathogenesis of GC remained unknown. We show here that Cav1-deficient mice, infected for 11 months with the CagA-delivery deficient H. pylori strain SS1, developed more severe gastritis and tissue damage, including loss of parietal cells and foveolar hyperplasia, and displayed lower colonisation of the gastric mucosa than wild-type B6129 littermates. Cav1-null mice showed enhanced infiltration of macrophages and B-cells and secretion of chemokines (RANTES but had reduced levels of CD25+ regulatory T-cells. Cav1-deficient human GC cells (AGS, infected with the CagA-delivery proficient H. pylori strain G27, were more sensitive to CagA-related cytoskeletal stress morphologies ("humming bird" compared to AGS cells stably transfected with Cav1 (AGS/Cav1. Infection of AGS/Cav1 cells triggered the recruitment of p120 RhoGTPase-activating protein/deleted in liver cancer-1 (p120RhoGAP/DLC1 to Cav1 and counteracted CagA-induced cytoskeletal rearrangements. In human GC cell lines (MKN45, N87 and mouse stomach tissue, H. pylori down-regulated endogenous expression of Cav1 independently of CagA. Mechanistically, H. pylori activated sterol-responsive element-binding protein-1 (SREBP1 to repress transcription of the human Cav1 gene from sterol-responsive elements (SREs in the proximal Cav1 promoter. These data suggested a protective role of Cav1 against H. pylori-induced inflammation and tissue damage. We propose that H. pylori exploits down-regulation of Cav1 to subvert the host's immune response and to promote signalling of its virulence factors in host cells.

Effect of Helicobacter pylori infection on IL-8, IL-1beta and COX-2 expression in patients with chronic gastritis and gastric cancer.

Science.gov (United States)

Bartchewsky, Waldemar; Martini, Mariana Rocha; Masiero, Mariana; Squassoni, Aline Candido; Alvarez, Marisa Claudia; Ladeira, Marcelo Sady; Salvatore, Daisy; Trevisan, Miriam; Pedrazzoli, José; Ribeiro, Marcelo Lima

2009-01-01

Helicobacter pylori infection is related to gastric cancer development, and chronic inflammation is presumed to be the main cause. The aim of the present study was to evaluate the influence of H. pylori cagA, vacA, iceA, and babA genotypes on COX-2, IL-1beta, and IL-8 expression. Of the 217 patients included in the study, 26 were uninfected, 127 had chronic gastritis and were H. pylori-positive, and 64 had gastric cancer. Bacterial genotypes were evaluated by polymerase chain reaction (PCR), and the expression values were determined by quantitative real-time PCR and immunohistochemistry. An association was found between the infection with cagA, vacA s1m1 strains and gastric cancer development. Regarding the 3' region of the cagA gene, we also found an association between the infection with cagA EPIYA-ABCCC strains and clinical outcome. Higher levels of IL-8, IL-1beta, and COX-2 were detected in gastric mucosa from infected patients with chronic gastritis, and they were also associated with the infection by cagA, vacA s1m1 strains. The IL-8 and IL-1beta levels decrease significantly from chronic gastritis to gastric cancer, while the relative expression remained unaltered when COX-2 expression was analyzed among patients with gastritis and cancer. Since inflammatory response to H. pylori infection plays an important role in cellular proliferation and gastric mucosal damage, the up-regulation of IL-1beta, IL-8, and COX-2 in patients with chronic gastritis has an important clinical implication in gastric carcinogenesis.

Inhibitory effect of piperine on Helicobacter pylori growth and adhesion to gastric adenocarcinoma cells

OpenAIRE

Tharmalingam, Nagendran; Kim, Sa-Hyun; Park, Min; Woo, Hyun Jun; Kim, Hyun Woo; Yang, Ji Yeong; Rhee, Ki-Jong; Kim, Jong Bae

2014-01-01

Background Piperine is a compound comprising 5-9% of black pepper (Piper nigrum), which has a variety of biological roles related to anticancer activities. Helicobacter pylori has been classified as a gastric carcinogen, because it causes gastritis and gastric cancer by injecting the virulent toxin CagA and translocating VacA. The present study investigated the inhibitory action of piperine on H. pylori growth and adhesion. Methods Inhibition of H. pylori growth was determined by the broth ma...

Differences in virulence markers between Helicobacter pylori strains from Iraq and those from Iran: potential importance of regional differences in H. pylori-associated disease.

Science.gov (United States)

Hussein, Nawfal R; Mohammadi, Marjan; Talebkhan, Yeganeh; Doraghi, Masoumeh; Letley, Darren P; Muhammad, Merdan K; Argent, Richard H; Atherton, John C

2008-05-01

Helicobacter pylori causes peptic ulceration and gastric adenocarcinoma; the latter is common in Iran but not in Iraq. We hypothesized that more virulent H. pylori strains may be found in Iran than in Iraq and so compared established and newly described virulence factors in strains from these countries. We studied 59 unselected dyspeptic patients from Iran and 49 from Iraq. cagA was found in similar proportions of strains from both countries (76% in Iran versus 71% in Iraq) and was significantly associated with peptic ulcer disease in Iraq (P dupA was found in similar proportions of Iranian and Iraqi strains (38% and 32%, respectively) and was associated with peptic ulceration in Iraqi patients (P pylori strains from Iraq and Iran possess virulence factors similar to those in Western countries. The presence of cagA with more phosphorylation motifs in Iranian strains may contribute to the higher incidence of gastric cancer. However, the association between strain virulence markers and disease in Iraq but not Iran suggests that other host and environmental factors may be more important in the disease-prone Iranian population.

The Prevalence of Helicobacter pylori Virulence Factors in Bhutan, Vietnam, and Myanmar Is Related to Gastric Cancer Incidence

Directory of Open Access Journals (Sweden)

Tran Thi Huyen Trang

2015-01-01

Full Text Available Gastric cancer is a significant health problem in Asia. Although the prevalence of Helicobacter pylori infection is similar in Bhutan, Vietnam, and Myanmar, the incidence of gastric cancer is highest in Bhutan, followed by Vietnam and Myanmar. We hypothesized that H. pylori virulence factors contribute to the differences. The status of cagA, vacA, jhp0562, and β-(1,3galT(jhp0563 was examined in 371 H. pylori-infected patients from Bhutan, Vietnam, and Myanmar. Each virulence factor could not explain the difference of the incidence of gastric cancer. However, the prevalence of quadruple-positive for cagA, vacA s1, vacA m1, and jhp0562-positive/β-(1,3galT-negative was significantly higher in Bhutan than in Vietnam and Myanmar and correlated with gastric cancer incidence. Moreover, gastritis-staging scores measured by histology of gastric mucosa were significantly higher in quadruple-positive strains. We suggest that the cagA, vacA s1, vacA m1, and jhp0562-positive/β-(1,3galT-negative genotype may play a role in the development of gastric cancer.

The relationship between helicobacter pylori infection and gastro-esophageal reflux disease

OpenAIRE

Batool M Mahdi

2011-01-01

Background : Gastro-esophageal reflux disease is a common condition, affecting 25%-40% of the population. Increasing attention has been paid to the relationship between Helicobacter pylori infection and reflux esophagitis. Aim: The aim of this study was to investigate the association between CagA+ H. pylori and endoscopically proven gastro-esophageal reflux disease. Patients and Methods: The study group included 60 hospital patients with gastro-esophageal reflux disease between 2007 and 2009 ...

Correlation between virulence markers of Helicobacter pylori in the oral cavity and gastric biopsies

Directory of Open Access Journals (Sweden)

Myriam Lucrecia MEDINA

2017-07-01

Full Text Available ABSTRACT BACKGROUND: The clinical outcome of Helicobacter pylori infection has been associated with virulence factors. The presence of these factors is useful as molecular markers in the identification of the high risk for developing severe gastric pathologies. OBJECTIVE: To correlate the presence of virulence markers cagA and bab2A of H. pylori in oral and gastric biopsy samples. METHODS: An observational, prospective, descriptive, and cross-sectional study was carried out between September 2011 and September 2012. Patients suffering dyspepsia with indication for upper gastrointestinal video endoscopy who attended the Gastroenterology Service of the Hospital Dr. Julio C. Perrando were included. Epidemiological investigation was completed. To detect the bacteria and their virulence genes, samples of saliva, dental plaque and gastric biopsy were taken and processed by PCR. RESULTS: Sixty-one patients were selected for this study (30 women and 31 men. H. pylori was detected in 31 gastric biopsies and 31 oral samples. Significant difference between oral and gastric samples was found in cagA genotype. Agreement between oral and gastric genotypes was found in 38.7% of samples from the same patient. CONCLUSION: This study is the first in provide information about the genotypes of the Argentinean Northeast H. pylori strains. Despite the high prevalence of H. pylori infection, the most of patients had less virulent genotypes in oral cavity and gastric tissue. The cagA / babA2 combination was not frequent in the samples studied. There was not a statistical correlation between the virulence genes and gastroduodenal or oral diseases. Although in some patients the same genotype was found both in oral and gastric samples, it cannot be ensure that they corresponding to the same strain because a DNA sequencing was not performed.

Relationship of interleukin-1B gene promoter region polymorphism with Helicobacter pylori infection and gastritis.

Science.gov (United States)

Ramis, Ivy Bastos; Vianna, Júlia Silveira; Halicki, Priscila Cristina Bartolomeu; Lara, Caroline; Tadiotto, Thássia Fernanda; da Silva Maciel, João Batista; Gonçalves, Carla Vitola; von Groll, Andrea; Dellagostin, Odir Antônio; da Silva, Pedro Eduardo Almeida

2015-09-29

Helicobacter pylori infection is associated with gastritis, peptic ulcer disease and gastric carcinoma. The severity of damage is determined by the interplay between environmental/behavioral factors, bacterial pathogenicity genes and host genetic polymorphisms that can influence the secretion levels of inflammatory cytokines. Accordingly, this study aimed to identify polymorphisms in the IL-1B and IL-1RN genes and their associations with H. pylori infection, cagA gene of H. pylori, and gastroduodenal diseases. Gastric biopsy samples from 151 patients infected with H. pylori and 76 uninfected individuals were analyzed. H. pylori infection was diagnosed by histology and PCR. Polymorphisms at positions -511, -31 and +3954 of the IL-1B gene were detected by PCR-RFLP, and an analysis of the VNTR polymorphism of the IL-1RN gene was performed by PCR. It was observed that the presence of the T/T genotype at position -511 and the C/C genotype at position -31 were associated with H. pylori infection and with an increased risk of gastritis in H. pylori-positive patients. Additionally, strains from patients H. pylori-positive carrying the cagA gene was significantly related with the T/T genotype at position -511 of IL-1B.  No association of polymorphisms at position +3954 of IL-1B and in the IL-1RN with H. pylori infection and with risk of severe gastric diseases was found. We demonstrated that polymorphisms in the promoter region of the IL-1B gene (at positions -511 and -31) are associated with an enhanced risk of H. pylori infection as well as gastritis in H. pylori-positive patients.

When is Helicobacter pylori acquired in populations in developing countries? A birth-cohort study in Bangladeshi children.

Science.gov (United States)

Kienesberger, Sabine; Perez-Perez, Guillermo I; Olivares, Asalia Z; Bardhan, Pradip; Sarker, Shafiqul A; Hasan, Kh Zahid; Sack, R Bradley; Blaser, Martin J

2018-03-01

Helicobacter pylori colonization is prevalent throughout the world, and is predominantly acquired during childhood. In developing countries, >70% of adult populations are colonized with H. pylori and >50% of children become colonized before the age of 10 years. However, the exact timing of acquisition is unknown. We assessed detection of H. pylori acquisition among a birth cohort of 105 children in Mirzapur, Bangladesh. Blood samples collected at time 0 (cord blood), and at 6, 12, 18, and 24 months of life were examined for the presence of IgG and IgA antibodies to whole cell H. pylori antigen and for IgG antibodies to the CagA antigen using specific ELISAs and immunoblotting. Breast milk samples were analyzed for H. pylori-specific IgA antibodies. Cord blood was used to establish maternal colonization status. H. pylori seroprevalence in the mothers was 92.8%. At the end of the two-year follow-up period, 50 (47.6%) of the 105 children were positive for H. pylori in more than one assay. Among the colonized children, CagA prevalence was 78.0%. A total of 58 children seroconverted: 50 children showed persistent colonization and 8 (7.6%) children showed transient seroconversion, but immunoblot analysis suggested that the transient seroconversion observed by ELISA may represent falsely positive results. Acquisition of H. pylori was not influenced by the mother H. pylori status in serum or breastmilk. In this population with high H. pylori prevalence, we confirmed that H. pylori in developing countries is detectable mainly after the first year of life.

Seroepidemiology of the Helicobacter pylori infection among people of Pishva city of Varamin

Directory of Open Access Journals (Sweden)

Maryam Abdi

2014-12-01

Full Text Available Background and Aim: The epidemiologic pattern of Helicobacter pylori infection is differed between developed countries and developing countries, and also it is depend on the total standard of living in each region. At the present study, the seroprevalence of H.pylori infection and effectiveness of underlying factors in prevalence of this infection among residents of Pishva city of Varamin was evaluated. Materials and Methods: This descriptive study was conducted after completion the questionnaire. The peripheral blood of 314 people without any confirmed gastric problem were collected. Then, the titer of total IgG and IgG anti CagA of H. pylori was evaluated by ELISA method. Consequently, the correlation between serologic data and different factors were analyzed by SPSS statistical software. Results: The existence of total IgG was detected in 164 (55.2% of 314 patients and was negative in 130 people (41.4%.Also, the IgG anti CagA were positive in 46 (29.1%, it was negative in 105 people (66.5% and the rested were in borderline. There was statistical meaningful correlation between positive result of serology test of IgG anti CagA to  some risk factors such as age, the number of the member of family, the educational status and occupation, the consumption of can, heart diseases, the rate of cholesterol, the history of gastrointestinal symptoms,  heartburn and reflux (P <0.05 . Conclusions: With regard to high prevalence of H. pylori in this area (55.2% and its presumptive effect in infected people, the necessary of hygiene education and precise control of infection is suggested.

Genetic affinities of Helicobacter pylori isolates from ethnic Arabs in Kuwait

Directory of Open Access Journals (Sweden)

Albert M John

2010-07-01

Full Text Available Abstract Helicobacter pylori is one of the most genetically diverse of bacterial species, and since the 5'-end of cagA gene and the middle allele of vacA gene of H. pylori from different populations exhibit considerable polymorphisms, these sequence diversities were used to gain insights into the genetic affinities of this gastric pathogen from different populations. Because the genetic affinity of Arab strains from the Arabian Gulf is not known, we carried out genetic analysis based on sequence diversities of the cagA and the vacA genes of H. pylori from 9 ethnic Arabs in Kuwait. The analysis showed that the Kuwaiti isolates are closely related to the Indo-European group of strains, although some strains have a tendency to form a separate cluster close to the Indo- European group, but clearly distinct from East Asian strains. However, these results need to be confirmed by analyses of neutral markers (house-keeping genes in a multi-locus sequence typing [MLST] platform. The profiling of virulence-associated genes may have resulted from ecologically distinct populations due to human migration and geographical separation over long periods of time.

Clinical relevance of the cagA, tnpA and tnpB genes in Helicobacter pylori

NARCIS (Netherlands)

Abadi, Amin Talebi Bezmin; Mobarez, Ashraf Mohhabati; Bonten, Marc J M; Wagenaar, Jaap A; Kusters, Johannes G

2014-01-01

BACKGROUND: Numerous proteins have been proposed as virulence factors for the gram negative gastric bacterium Helicobacter pylori but only for a few this has unequivocally been demonstrated. The aim of the current study was to evaluate the association of the putative virulence factors tnpA and tnpB

Detection of Helicobacter pylori vacA, cagA and iceA1 virulence ...

African Journals Online (AJOL)

Background: Helicobactor pylori (H. pylori) virulence markers would be useful to predict peptic ulcer disease (PUD) or gastric cancer. Aim: In Egypt, since inadequate data are present regarding H. pylori virulence–related genes in different age group patients with gastro-duodenal diseases, it becomes crucial to study the ...

Helicobacter pylori HopE and HopV porins present scarce expression among clinical isolates

Science.gov (United States)

Lienlaf, Maritza; Morales, Juan Pablo; Díaz, María Inés; Díaz, Rodrigo; Bruce, Elsa; Siegel, Freddy; León, Gloria; Harris, Paul R; Venegas, Alejandro

2010-01-01

AIM: To evaluate how widely Helicobacter pylori (H. pylori) HopE and HopV porins are expressed among Chilean isolates and how seroprevalent they are among infected patients in Chile. METHODS: H. pylori hopE and hopV genes derived from strain CHCTX-1 were cloned by polymerase chain reaction (PCR), sequenced and expressed in Escherichia coli AD494 (DE3). Gel-purified porins were used to prepare polyclonal antibodies. The presence of both genes was tested by PCR in a collection of H. pylori clinical isolates and their expression was detected in lysates by immunoblotting. Immune responses against HopE, HopV and other H. pylori antigens in sera from infected and non-infected patients were tested by Western blotting using these sera as first antibody on recombinant H. pylori antigens. RESULTS: PCR and Western blotting assays revealed that 60 and 82 out of 130 Chilean isolates carried hopE and hopV genes, respectively, but only 16 and 9, respectively, expressed these porins. IgG serum immunoreactivity evaluation of 69 H. pylori-infected patients revealed that HopE and HopV were infrequently recognized (8.7% and 10.1% respectively) compared to H. pylori VacA (68.1%) and CagA (59.5%) antigens. Similar values were detected for IgA serum immunoreactivity against HopE (11.6%) and HopV (10.5%) although lower values for VacA (42%) and CagA (17.4%) were obtained when compared to the IgG response. CONCLUSION: A scarce expression of HopE and HopV among Chilean isolates was found, in agreement with the infrequent seroconversion against these antigens when tested in infected Chilean patients. PMID:20082477

Mechanisms of disease: Helicobacter pylori virulence factors.

Science.gov (United States)

Yamaoka, Yoshio

2010-11-01

Helicobacter pylori plays an essential role in the development of various gastroduodenal diseases; however, only a small proportion of people infected with H. pylori develop these diseases. Some populations that have a high prevalence of H. pylori infection also have a high incidence of gastric cancer (for example, in East Asia), whereas others do not (for example, in Africa and South Asia). Even within East Asia, the incidence of gastric cancer varies (decreasing in the south). H. pylori is a highly heterogeneous bacterium and its virulence varies geographically. Geographic differences in the incidence of gastric cancer can be explained, at least in part, by the presence of different types of H. pylori virulence factor, especially CagA, VacA and OipA. However, it is still unclear why the pathogenicity of H. pylori increased as it migrated from Africa to East Asia during the course of evolution. H. pylori infection is also thought to be involved in the development of duodenal ulcer, which is at the opposite end of the disease spectrum to gastric cancer. This discrepancy can be explained in part by the presence of H. pylori virulence factor DupA. Despite advances in our understanding of the development of H. pylori-related diseases, further work is required to clarify the roles of H. pylori virulence factors.

Differences in Virulence Markers between Helicobacter pylori Strains from Iraq and Those from Iran: Potential Importance of Regional Differences in H. pylori-Associated Disease▿

Science.gov (United States)

Hussein, Nawfal R.; Mohammadi, Marjan; Talebkhan, Yeganeh; Doraghi, Masoumeh; Letley, Darren P.; Muhammad, Merdan K.; Argent, Richard H.; Atherton, John C.

2008-01-01

Helicobacter pylori causes peptic ulceration and gastric adenocarcinoma; the latter is common in Iran but not in Iraq. We hypothesized that more virulent H. pylori strains may be found in Iran than in Iraq and so compared established and newly described virulence factors in strains from these countries. We studied 59 unselected dyspeptic patients from Iran and 49 from Iraq. cagA was found in similar proportions of strains from both countries (76% in Iran versus 71% in Iraq) and was significantly associated with peptic ulcer disease in Iraq (P ≤ 0.01) but not in Iran. cagA alleles encoding four or more tyrosine phosphorylation motifs were found in 12% of the Iranian strains but none of the Iraqi strains (P = 0.02). There were no significant differences in the vacA signal-, middle-, or intermediate-region types between Iranian and Iraqi strains. Among the strains from Iran, vacA genotypes showed no specific peptic ulcer associations, but among the strains from Iraq, vacA i1 strains were associated with gastric ulcer (P ≤ 0.02), mimicking their previously demonstrated association with gastric cancer in Iran. dupA was found in similar proportions of Iranian and Iraqi strains (38% and 32%, respectively) and was associated with peptic ulceration in Iraqi patients (P ≤ 0.01) but not Iranian patients. H. pylori strains from Iraq and Iran possess virulence factors similar to those in Western countries. The presence of cagA with more phosphorylation motifs in Iranian strains may contribute to the higher incidence of gastric cancer. However, the association between strain virulence markers and disease in Iraq but not Iran suggests that other host and environmental factors may be more important in the disease-prone Iranian population. PMID:18353934

Phylogenetic analysis, based on EPIYA repeats in the cagA gene of Indian Helicobacter pylori, and the implications of sequence variation in tyrosine phosphorylation motifs on determining the clinical outcome

Directory of Open Access Journals (Sweden)

Santosh K. Tiwari

2011-01-01

Full Text Available The population of India harbors one of the world's most highly diverse gene pools, owing to the influx of successive waves of immigrants over regular periods in time. Several phylogenetic studies involving mitochondrial DNA and Y chromosomal variation have demonstrated Europeans to have been the first settlers in India. Nevertheless, certain controversy exists, due to the support given to the thesis that colonization was by the Austro-Asiatic group, prior to the Europeans. Thus, the aim was to investigate pre-historic colonization of India by anatomically modern humans, using conserved stretches of five amino acid (EPIYA sequences in the cagA gene of Helicobacter pylori. Simultaneously, the existence of a pathogenic relationship of tyrosine phosphorylation motifs (TPMs, in 32 H. pylori strains isolated from subjects with several forms of gastric diseases, was also explored. High resolution sequence analysis of the above described genes was performed. The nucleotide sequences obtained were translated into amino acids using MEGA (version 4.0 software for EPIYA. An MJ-Network was constructed for obtaining TPM haplotypes by using NETWORK (version 4.5 software. The findings of the study suggest that Indian H. pylori strains share a common ancestry with Europeans. No specific association of haplotypes with the outcome of disease was revealed through additional network analysis of TPMs.

The Prevalence of Mixed Helicobacter pylori Infections in Symptomatic and Asymptomatic Subjects in Dhaka, Bangladesh.

Science.gov (United States)

Kibria, Khandoker Mohammad K; Hossain, Md Enayet; Sultana, Jinath; Sarker, Shafiqul A; Bardhan, Pradip Kumar; Rahman, Motiur; Nahar, Shamsun

2015-10-01

Helicobacter pylori is a highly genetically diverse bacterial species, which can persist in the gastric environment for decades. Recent studies have shown that single infections predominate in developed countries, whereas mixed infections are more prevalent in developing countries. Mixed infections of this bacterium may be important for adaptation to the hostile gastric environment and may facilitate dyspeptic symptoms. To calculate the prevalence of mixed infections in symptomatic and asymptomatic subjects, 2010 H. pylori isolates collected from 83 symptomatic and 91 asymptomatic subjects from Dhaka, Bangladesh, were analyzed by (i) random amplified polymorphic DNA fingerprinting (RAPD) and (ii) multiplex PCR amplification for cagA and vacA virulence gene alleles. The overall prevalence of mixed H. pylori infection was 60.15% (77/128), indicating substantial co-colonization in this population. We additionally found that symptomatic subjects (53%) had a significantly higher rate of mixed infection than asymptomatic individuals (36.3%) (p = .016) and that the prevalence of the cagA and vacA and vacA m1/s1 and vacA m2/s1 alleles were higher in subjects with mixed infection. Our findings suggest that an increased diversity of the H. pylori strains in the gastric environment may contribute to the development of disease symptoms. © 2015 John Wiley & Sons Ltd.

Helicobacter pylori infection in women with Hashimoto thyroiditis: A case-control study.

Science.gov (United States)

Shmuely, Haim; Shimon, Ilan; Gitter, Limor Azulay

2016-07-01

An association between Helicobacter pylori (H pylori) infection as environmental risk factors for Hashimoto thyroiditis (HT) has been reported. We investigated this hypothesis in women in which HT is more common. Serum immunoglobulin G antibodies against H pylori (enzyme-linked immunosorbent assay), CagA protein (Western blot assay), circulating antibodies to thyroid antigens, mainly thyroperoxidase (TPOAbs) and thyroglobulin (TgAbs), were tested in 101 females with HT and 111 non-HT control women without a history of autoimmune disease. Thyroid function, socioeconomic status at childhood, and family history of thyroid malfunction were also studied. Forty-seven HT women (46.5%) tested seropositive for H pylori versus 48 controls (43.2%; P = 0.63). The prevalence of anti-CagA antibodies was 21.3% in HT-infected patients and 31.2% in infected controls (P = 0.352). Women with HT were older than the controls at a significance level of 0.03, and higher prevalence of hypothyroidism (69% vs 13.5%, respectively) and family history of thyroid malfunction (59% vs 34%, respectively) (P thyroid malfunction was independently associated with an increased risk of HT (odds ratio 3.39, 95% confidence interval 1.86-6.18, P thyroid malfunction is a risk factor for HT.

Helicobacter pylori Eradication in Patients with Immune Thrombocytopenic Purpura: A Review and the Role of Biogeography.

Science.gov (United States)

Frydman, Galit H; Davis, Nick; Beck, Paul L; Fox, James G

2015-08-01

Idiopathic thrombocytopenic purpura (ITP) is typically a diagnosis of exclusion, assigned by clinicians after ruling out other identifiable etiologies. Since a report by Gasbarrini et al. in 1998, an accumulating body of evidence has proposed a pathophysiological link between ITP and chronic Helicobacter pylori (H. pylori) infection. Clinical reports have described a spontaneous resolution of ITP symptoms in about 50% of chronic ITP patients following empirical treatment of H. pylori infection, but response appears to be geography dependent. Studies have also documented that ITP patients in East Asian countries are more likely to express positive antibody titers against H. pylori-specific cytotoxic-associated gene A (CagA), a virulence factor that is associated with an increased risk for gastric diseases including carcinoma. While a definitive mechanism by which H. pylori may induce thrombocytopenia remains elusive, proposed pathways include molecular mimicry of CagA by host autoantibodies against platelet surface glycoproteins, as well as perturbations in the phagocytic activity of monocytes. Traditional treatments of ITP have been largely empirical, involving the use of immunosuppressive agents and immunoglobulin therapy. However, based on the findings of clinical reports emerging over the past 20 years, health organizations around the world increasingly suggest the detection and eradication of H. pylori as a treatment for ITP. Elucidating the exact molecular mechanisms of platelet activation in H. pylori-positive ITP patients, while considering biogeographical differences in response rates, could offer insight into how best to use clinical H. pylori eradication to treat ITP, but will require well-designed studies to confirm the suggested causative relationship between bacterial infection and an autoimmune disease state. © 2015 John Wiley & Sons Ltd.

Helicobacter pylori Eradication in Patients with Immune Thrombocytopenic Purpura: A Review and the Role of Biogeography

Science.gov (United States)

Frydman, Galit H.; Davis, Nick; Beck, Paul L.; Fox, James G.

2015-01-01

Idiopathic thrombocytopenic purpura (ITP) is typically a diagnosis of exclusion, assigned by clinicians after ruling out other identifiable etiologies. Since a report by Gasbarrini et al. in 1998, an accumulating body of evidence has proposed a pathophysiological link between ITP and chronic Helicobacter pylori (H. pylori) infection. Clinical reports have described a spontaneous resolution of ITP symptoms in about 50% of chronic ITP patients following empirical treatment of H. pylori infection, but response appears to be geography dependent. Studies have also documented that ITP patients in East Asian countries are more likely to express positive antibody titers against H. pylori-specific cytotoxic-associated gene A (CagA), a virulence factor that is associated with an increased risk for gastric diseases including carcinoma. While a definitive mechanism by which H. pylori may induce thrombocytopenia remains elusive, proposed pathways include molecular mimicry of CagA by host autoantibodies against platelet surface glycoproteins, as well as perturbations in the phagocytic activity of monocytes. Traditional treatments of ITP have been largely empirical, involving the use of immunosuppressive agents and immunoglobulin therapy. However, based on the findings of clinical reports emerging over the past 20 years, health organizations around the world increasingly suggest the detection and eradication of H. pylori as a treatment for ITP. Elucidating the exact molecular mechanisms of platelet activation in H. pylori-positive ITP patients, while considering biogeographical differences in response rates, could offer insight into how best to use clinical H. pylori eradication to treat ITP, but will require well-designed studies to confirm the suggested causative relationship between bacterial infection and an autoimmune disease state. PMID:25728540

Development of gastric cancer associated with Helicobacter pylori infection.

Science.gov (United States)

Sugiyama, Toshiro

2004-09-01

Helicobacter pylori infection is associated with histological gastritis, gastric atrophy, gastric cancer and mucosa-associated lymphoid tissue lymphoma in the stomach. However, gastric cancer only develops in a minority of infected individuals. Such clinical diversity is caused by variations in the interactions between H. pylori pathogenicity, host susceptibility, and environmental factors. Based on evidence from three prospective epidemiological studies, the International Agency for Research on Cancer and the World Health Organization (IARC/WHO) concluded in 1994 that H. pylori has a causal linkage to gastric carcinogenesis and is a definite carcinogen in humans. Two large-scale, prospective, epidemiological studies have recently been reported in Japan and have confirmed that H. pylori infection constitutes a high risk factor for the development of gastric cancer, at least in males. In order to obtain evidence that eradication of H. pylori leads to a reduction in the occurrence of gastric cancer, reversibility of precancerous lesions, gastric atrophy or intestinal metaplasia should be proven after eradication treatment. A biopsy specimen from the lesser curvature of the corpus is the most sensitive for evaluating the regression of gastric atrophy on histology, and the evaluation needs be conducted at least 13 months after treatment. In a Mongolian gerbil model with or without low-dose chemical carcinogens, it has been demonstrated that H. pylori can lead to the development of gastric cancer. Experimental studies have elucidated that virulence factors of H. pylori interact with gastric epithelial cell signaling related to carcinogenesis. The cag pathogenicity island (cagPAI) is a major virulence gene cluster; it encodes the type IV secretion machinery system forming a cylinder-like structure. The CagA protein is translocated into target cells via this secretion system and induces a hummingbird phenotype, a growth factor-like effect. The other gene products are

Helicobacter pylori seropositivity and risk of lung cancer.

Directory of Open Access Journals (Sweden)

Jill Koshiol

Full Text Available Lung cancer is the leading cause of cancer mortality worldwide. Helicobacter pylori (H. pylori is a risk factor for distal stomach cancer, and a few small studies have suggested that H. pylori may be a potential risk factor for lung cancer. To test this hypothesis, we conducted a study of 350 lung adenocarcinoma cases, 350 squamous cell carcinoma cases, and 700 controls nested within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC cohort of male Finnish smokers. Controls were one-to-one matched by age and date of baseline serum draw. Using enzyme-linked immunosorbent assays to detect immunoglobulin G antibodies against H. pylori whole-cell and cytotoxin-associated gene (CagA antigens, we calculated odds ratios (ORs and 95% confidence intervals (95% CIs for associations between H. pylori seropositivity and lung cancer risk using conditional logistic regression. H. pylori seropositivity was detected in 79.7% of cases and 78.5% of controls. After adjusting for pack-years and cigarettes smoked per day, H. pylori seropositivity was not associated with either adenocarcinoma (OR: 1.1, 95% CI: 0.75-1.6 or squamous cell carcinoma (OR: 1.1, 95% CI: 0.77-1.7. Results were similar for CagA-negative and CagA-positive H. pylori seropositivity. Despite earlier small studies suggesting that H. pylori may contribute to lung carcinogenesis, H. pylori seropositivity does not appear to be associated with lung cancer.

Downregulated regulatory T cell function is associated with increased peptic ulcer in Helicobacter pylori-infection.

Science.gov (United States)

Bagheri, Nader; Shirzad, Hedayatollah; Elahi, Shokrollah; Azadegan-Dehkordi, Fatemeh; Rahimian, Ghorbanali; Shafigh, Mohammedhadi; Rashidii, Reza; Sarafnejad, Abdulfatah; Rafieian-Kopaei, Mahmoud; Faridani, Rana; Tahmasbi, Kamran; Kheiri, Soleiman; Razavi, Alireza

2017-09-01

Helicobacter pylori (H. pylori) chronically colonizes gastric/duodenal mucosa and induces gastroduodenal disease such as gastritis and peptic ulcer and induces vigorous innate and specific immune responses; however, the infection is not removed, a state of chronic active gastritis persists for life if untreated. The objective of this study was to determine the number of regulatory T cells (Tregs) in gastric mucosa of patients with gastritis and peptic ulcer and determined the relationship between main virulence factor of H. pylori and Tregs. A total of 89 patients with gastritis, 63 patients with peptic ulcer and 40 healthy, H. pylori-negative subjects were enrolled in this study. Expression of CD4 and Foxp3 was determined by immunohistochemistry. Antrum biopsy was obtained for detection of H. pylori, bacterial virulence factors and histopathological assessments. TGF-β1, IL-10 and FOXP3 expressions were determined by real-time polymerase chain reaction (qPCR). The numbers of CD4 + and Foxp3 + T cells as well as the expression of IL-10, TGF-β1, FOXP3, INF-γ and IL-17A in infected patients were significantly higher than the ones in uninfected patients. Also, the number of CD4 + T cells was independent on the vacuolating cytotoxin A (vacA) and outer inflammatory protein A (oipA), but it was positively correlated with cytotoxin-associated gene A (cagA). Instead, the number of Foxp3 + T cells was dependent on the vacA and oipA, but it was independent on cagA. The number of Foxp3 + T cells and the expression of IL-10, TGF-β1 and FOXP3 in infected patients with gastritis were significantly higher than the ones in infected patients with peptic ulcer. Moreover, the number of CD4 + T cells and the expression of IL-17A and INF-γ was the lowest in the gastritis patients, however, increased progressively in the peptic ulcer patients. Additionally, the numbers of CD4 + and Foxp3 + T cells as well as the expression of IL-10, TGF-β1, FOXP3 and INF-γ were positively

Helicobacter pylori infection induces genetic instability of nuclear and mitochondrial DNA in gastric cells

DEFF Research Database (Denmark)

Machado, Ana Manuel Dantas; Figueiredo, Ceu; Touati, Eliette

2009-01-01

of genetic instabilities in the nuclear and mitochondrial DNA (mtDNA) were examined. EXPERIMENTAL DESIGN: We observed the effects of H. pylori infection on a gastric cell line (AGS), on C57BL/6 mice, and on individuals with chronic gastritis. In AGS cells, the effect of H. pylori infection on base excision...... cells and chronic gastritis tissue were determined by PCR, single-stranded conformation polymorphism, and sequencing. H. pylori vacA and cagA genotyping was determined by multiplex PCR and reverse hybridization. RESULTS: Following H. pylori infection, the activity and expression of base excision repair...... and MMR are down-regulated both in vitro and in vivo. Moreover, H. pylori induces genomic instability in nuclear CA repeats in mice and in mtDNA of AGS cells and chronic gastritis tissue, and this effect in mtDNA is associated with bacterial virulence. CONCLUSIONS: Our results suggest that H. pylori...

Helicobacter pylori infection, chronic corpus atrophic gastritis and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort: A nested case-control study.

Science.gov (United States)

Huang, Jiaqi; Zagai, Ulrika; Hallmans, Göran; Nyrén, Olof; Engstrand, Lars; Stolzenberg-Solomon, Rachael; Duell, Eric J; Overvad, Kim; Katzke, Verena A; Kaaks, Rudolf; Jenab, Mazda; Park, Jin Young; Murillo, Raul; Trichopoulou, Antonia; Lagiou, Pagona; Bamia, Christina; Bradbury, Kathryn E; Riboli, Elio; Aune, Dagfinn; Tsilidis, Konstantinos K; Capellá, Gabriel; Agudo, Antonio; Krogh, Vittorio; Palli, Domenico; Panico, Salvatore; Weiderpass, Elisabete; Tjønneland, Anne; Olsen, Anja; Martínez, Begoña; Redondo-Sanchez, Daniel; Chirlaque, Maria-Dolores; Hm Peeters, Petra; Regnér, Sara; Lindkvist, Björn; Naccarati, Alessio; Ardanaz, Eva; Larrañaga, Nerea; Boutron-Ruault, Marie-Christine; Rebours, Vinciane; Barré, Amélie; Bueno-de-Mesquita, H B As; Ye, Weimin

2017-04-15

The association between H. pylori infection and pancreatic cancer risk remains controversial. We conducted a nested case-control study with 448 pancreatic cancer cases and their individually matched control subjects, based on the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, to determine whether there was an altered pancreatic cancer risk associated with H. pylori infection and chronic corpus atrophic gastritis. Conditional logistic regression models were applied to calculate odds ratios (ORs) and corresponding 95% confidence intervals (CIs), adjusted for matching factors and other potential confounders. Our results showed that pancreatic cancer risk was neither associated with H. pylori seropositivity (OR = 0.96; 95% CI: 0.70, 1.31) nor CagA seropositivity (OR = 1.07; 95% CI: 0.77, 1.48). We also did not find any excess risk among individuals seropositive for H. pylori but seronegative for CagA, compared with the group seronegative for both antibodies (OR = 0.94; 95% CI: 0.63, 1.38). However, we found that chronic corpus atrophic gastritis was non-significantly associated with an increased pancreatic cancer risk (OR = 1.35; 95% CI: 0.77, 2.37), and although based on small numbers, the excess risk was particularly marked among individuals seronegative for both H. pylori and CagA (OR = 5.66; 95% CI: 1.59, 20.19, p value for interaction cancer risk in western European populations. However, the suggested association between chronic corpus atrophic gastritis and pancreatic cancer risk warrants independent verification in future studies, and, if confirmed, further studies on the underlying mechanisms. © 2016 UICC.

The internalization of Helicobacter pylori plays a role in the failure of H. pylori eradication.

Science.gov (United States)

Wang, You-Hua; Lv, Zhi-Fa; Zhong, Yao; Liu, Dong-Sheng; Chen, Shu-Ping; Xie, Yong

2017-02-01

Helicobacter pylori (H. pylori) internalization involves invasion of cells by the bacterium. Several studies have shown that H. pylori can invade human gastric epithelial cells, immune cells, and Candida yeast in vivo and in vitro. Whether bacterial invasion plays a role in eradication failure is unclear. To investigate the relationship between H. pylori invasion of GES-1 cells and H. pylori eradication failure. Forty-two clinical strains isolated from H. pylori-positive patients with different outcomes after treatment with furazolidone-based therapy were examined (17 failures and 25 successes). The H. pylori strains were shown to be susceptible to amoxicillin and furazolidone, and the patients also exhibited good compliance. Genotyping was performed for cagA and vacA (s and m). The antibiotic susceptibility of the strains to amoxicillin, furazolidone, clarithromycin, metronidazole, and levofloxacin was determined by E-tests. The levels of H. pylori invasion of GES-1 cells were detected by gentamicin colony-forming unit assays. The internalization level in the eradication success group was 5.40±5.78 × 10 -3  cfu/cell, and the median was 6.194 × 10 -3  cfu/cell; the internalization level in the eradication failure group was 8.98±5.40 × 10 -3  cfu/cell, and the median was 10.28 × 10 -3  cfu/cell. The eradication failure group showed a greater invasion level than the eradication success group (Pinternalization levels were compared (P>.05). The results showed that H. pylori invasion of the gastric epithelia might play a role in eradication failure. © 2016 John Wiley & Sons Ltd.

Analysis of clinical isolates of Helicobacter pylori in Pakistan reveals high degrees of pathogenicity and high frequencies of antibiotic resistance.

Science.gov (United States)

Rasheed, Faisal; Campbell, Barry James; Alfizah, Hanafiah; Varro, Andrea; Zahra, Rabaab; Yamaoka, Yoshio; Pritchard, David Mark

2014-10-01

Antibiotic resistance in Helicobacter pylori contributes to failure in eradicating the infection and is most often due to point and missense mutations in a few key genes. The antibiotic susceptibility profiles of H. pylori isolates from 46 Pakistani patients were determined by Etest. Resistance and pathogenicity genes were amplified, and sequences were analyzed to determine the presence of mutations. A high percentage of isolates (73.9%) were resistant to metronidazole (MTZ), with considerable resistance to clarithromycin (CLR; 47.8%) and amoxicillin (AML; 54.3%) also observed. Relatively few isolates were resistant to tetracycline (TET; 4.3%) or to ciprofloxacin (CIP; 13%). However, most isolates (n = 43) exhibited resistance to one or more antibiotics. MTZ-resistant isolates contained missense mutations in oxygen-independent NADPH nitroreductase (RdxA; 8 mutations found) and NADH flavin oxidoreductase (FrxA; 4 mutations found). In the 23S rRNA gene, responsible for CLR resistance, a new point mutation (A2181G) and 4 previously reported mutations were identified. Pathogenicity genes cagA, dupA, and vacA s1a/m1 were detected frequently in isolates which were also found to be resistant to MTZ, CLR, and AML. A high percentage of CagA and VacA seropositivity was also observed in these patients. Phylogenetic analysis of partial sequences showed uniform distribution of the 3' region of cagA throughout the tree. We have identified H. pylori isolates in Pakistan which harbor pathogenicity genes and worrying antibiotic resistance profiles as a result of having acquired multiple point and missense mutations. H. pylori eradication regimens should therefore be reevaluated in this setting. © 2014 John Wiley & Sons Ltd.

Correlation of Helicobacter pylori genotypes with gastric histopathology in the central region of a South-European country

OpenAIRE

Almeida, N; Donato, MM; Romãozinho, JM; Luxo, C; Cardoso, O; Cipriano, MA; Marinho, C; Fernandes, A; Sofia, C

2015-01-01

BACKGROUND: Outcome of Helicobacter pylori (H. pylori) infection results from interaction of multiple variables including host, environmental and bacterial-associated virulence factors. AIM: This study aimed to investigate the correlation of cagA, cagE, vacA, iceA and babA2 genotypes with gastric histopathology and disease phenotype in the central region of a South-European country. METHODS: This prospective study involved 148 infected patients (110 female; mean age 43.5 ± 13.4...

Role of dupA in virulence of Helicobacter pylori.

Science.gov (United States)

Talebi Bezmin Abadi, Amin; Perez-Perez, Guillermo

2016-12-14

Helicobacter pylori ( H. pylori ) is a gastric human pathogen associated with acute and chronic gastritis, 70% of all gastric ulcers, 85% of all duodenal ulcers, and both forms of stomach cancer, mucosal-associated lymphoid tissue (MALT) lymphoma and adenocarcinoma. Recently, attention has focused on possible relationship between presence of certain virulence factor and H. pylori -associated diseases. Some contradictory data between this bacterium and related disorders has been observed since not all the colonized individuals develop to severe disease. The reported diseases plausibility related to H. pylori specific virulence factors became an interesting story about this organism. Although a number of putative virulence factors have been identified including cytotoxin-associated gene a ( cagA ) and vacA , there are conflicting data about their actual participation as specific risk factor for H. pylori -related diseases. Duodenal ulcer promoting gene a ( dupA ) is a virulence factor of H. pylori that is highly associated with duodenal ulcer development and reduced risk of gastric cancer. The prevalence of dupA in H. pylori strains isolated from western countries is relatively higher than in H. pylori strains from Asian countries. Current confusing epidemiological reports will continue unless future sophisticated and molecular studies provide data on functional and complete dupA cluster in H. pylori infected individuals. This paper elucidates available knowledge concerning role of dupA in virulence of H. pylori after a decade of its discovery.

Helicobacter pylori-induced premature senescence of extragastric cells may contribute to chronic skin diseases.

Science.gov (United States)

Lewinska, Anna; Wnuk, Maciej

2017-04-01

Helicobacter pylori, one of the most frequently observed bacterium in the human intestinal flora, has been widely studied since Marshall and Warren documented a link between the presence of H. pylori in the gastrointestinal tract and gastritis and gastric ulcers. Interestingly, H. pylori has also been found in several other epithelial tissues, including the eyes, ears, nose and skin that may have direct or indirect effects on host physiology and may contribute to extragastric diseases, e.g. chronic skin diseases. More recently, it has been shown that H. pylori cytotoxin CagA expression induces cellular senescence of human gastric nonpolarized epithelial cells that may lead to gastrointestinal disorders and systemic inflammation. Here, we hypothesize that also chronic skin diseases may be promoted by stress-induced premature senescence (SIPS) of skin cells, namely fibroblasts and keratinocytes, stimulated with H. pylori cytotoxins. Future studies involving cell culture models and clinical specimens are needed to verify the involvement of H. pylori in SIPS-based chronic skin diseases.

On the importance of developing a new generation of breath tests for Helicobacter pylori detection.

Science.gov (United States)

Kushch, Ievgeniia; Korenev, Nikolai; Kamarchuk, Lyudmila; Pospelov, Alexander; Kravchenko, Andrey; Bajenov, Leonid; Kabulov, Mels; Amann, Anton; Kamarchuk, Gennadii

2015-12-15

State-of-the-art methods for non-invasive detection of the Helicobacter pylori (H. pylori) infection have been considered. A reported global tendency towards a non-decreasing prevalence of H. pylori worldwide could be co-influenced by the functional limitations of urea breath tests (UBTs), currently preferred for the non-invasive recognition of H. pylori in a clinical setting. Namely, the UBTs can demonstrate false-positive or false-negative results. Within this context, limitations of conventional clinically exploited H. pylori tests have been discussed to justify the existing need for the development of a new generation of breath tests for the detection of H. pylori and the differentiation of pathogenic and non-pathogenic strains of the bacterium. This paper presents the results of a pilot clinical study aimed at evaluating the development and diagnostic potential of a new method based on the detection of the non-urease products of H. pylori vital activity in exhaled gas. The characteristics of breath of adolescents with H. pylori-positive and H. pylori-negative functional dyspepsia, together with a consideration of the cytotoxin-associated gene A (CagA) status of H. pylori-positive subjects, have been determined for the first time using innovative point-contact nanosensor devices based on salts of the organic conductor tetracyanoquinodimethane (TCNQ). The clinical and diagnostic relevance of the response curves of the point-contact sensors was assessed. It was found that the recovery time of the point-contact sensors has a diagnostic value for differentiation of the H. pylori-associated peptic ulcer disease. The diagnostically significant elongation of the recovery time was even more pronounced in patients infected with CagA-positive H. pylori strains compared to the CagA-negative patients. Taking into account the operation of the point-contact sensors in the real-time mode, the obtained results are essential prerequisites for the development of a fast and

Multiplex-PCR-Based Screening and Computational Modeling of Virulence Factors and T-Cell Mediated Immunity in Helicobacter pylori Infections for Accurate Clinical Diagnosis.

Science.gov (United States)

Oktem-Okullu, Sinem; Tiftikci, Arzu; Saruc, Murat; Cicek, Bahattin; Vardareli, Eser; Tozun, Nurdan; Kocagoz, Tanil; Sezerman, Ugur; Yavuz, Ahmet Sinan; Sayi-Yazgan, Ayca

2015-01-01

The outcome of H. pylori infection is closely related with bacteria's virulence factors and host immune response. The association between T cells and H. pylori infection has been identified, but the effects of the nine major H. pylori specific virulence factors; cagA, vacA, oipA, babA, hpaA, napA, dupA, ureA, ureB on T cell response in H. pylori infected patients have not been fully elucidated. We developed a multiplex- PCR assay to detect nine H. pylori virulence genes with in a three PCR reactions. Also, the expression levels of Th1, Th17 and Treg cell specific cytokines and transcription factors were detected by using qRT-PCR assays. Furthermore, a novel expert derived model is developed to identify set of factors and rules that can distinguish the ulcer patients from gastritis patients. Within all virulence factors that we tested, we identified a correlation between the presence of napA virulence gene and ulcer disease as a first data. Additionally, a positive correlation between the H. pylori dupA virulence factor and IFN-γ, and H. pylori babA virulence factor and IL-17 was detected in gastritis and ulcer patients respectively. By using computer-based models, clinical outcomes of a patients infected with H. pylori can be predicted by screening the patient's H. pylori vacA m1/m2, ureA and cagA status and IFN-γ (Th1), IL-17 (Th17), and FOXP3 (Treg) expression levels. Herein, we report, for the first time, the relationship between H. pylori virulence factors and host immune responses for diagnostic prediction of gastric diseases using computer-based models.

The cag PAI is intact and functional but HP0521 varies significantly in Helicobacter pylori isolates from Malaysia and Singapore.

Science.gov (United States)

Schmidt, H-M A; Andres, S; Nilsson, C; Kovach, Z; Kaakoush, N O; Engstrand, L; Goh, K-L; Fock, K M; Forman, D; Mitchell, H

2010-04-01

Helicobacter pylori-related disease is at least partially attributable to the genotype of the infecting strain, particularly the presence of specific virulence factors. We investigated the prevalence of a novel combination of H. pylori virulence factors, including the cag pathogenicity island (PAI), and their association with severe disease in isolates from the three major ethnicities in Malaysia and Singapore, and evaluated whether the cag PAI was intact and functional in vitro. Polymerase chain reaction (PCR) was used to detect dupA, cagA, cagE, cagT, cagL and babA, and to type vacA, the EPIYA motifs, HP0521 alleles and oipA ON status in 159 H. pylori clinical isolates. Twenty-two strains were investigated for IL-8 induction and CagA translocation in vitro. The prevalence of cagA, cagE, cagL, cagT, babA, oipA ON and vacA s1 and i1 was >85%, irrespective of the disease state or ethnicity. The prevalence of dupA and the predominant HP0521 allele and EPIYA motif varied significantly with ethnicity (p < 0.05). A high prevalence of an intact cag PAI was found in all ethnic groups; however, no association was observed between any virulence factor and disease state. The novel association between the HP0521 alleles, EPIYA motifs and host ethnicity indicates that further studies to determine the function of this gene are important.

Epstein Barr virus and Helicobacter pylori co-infection are positively associated with severe gastritis in pediatric patients.

Directory of Open Access Journals (Sweden)

María G Cárdenas-Mondragón

Full Text Available H. pylori infection is acquired during childhood and causes a chronic inflammatory response in the gastric mucosa, which is considered the main risk factor to acquire gastric cancer (GC later in life. More recently, infection by Epstein-Barr virus (EBV have also been associated with GC. The role of EBV in early inflammatory responses and its relationship with H. pylori infection remains poorly studied. Here, we assessed whether EBV infection in children correlated with the stage of gastritis and whether co-infection with H. pylori affected the severity of inflammation.333 pediatric patients with chronic abdominal pain were studied. From them, gastric biopsies were taken and inflammation graded according to the Sydney system; peripheral blood was drawn and antibodies against EBV (IgG and IgM anti-VCA and H. pylori (IgG anti-whole bacteria and anti-CagA were measured in sera. We found that children infected only by EBV presented mild mononuclear (MN and none polymorphonuclear (PMN cell infiltration, while those infected by H. pylori presented moderate MN and mild PMN. In contrast, patients co-infected with both pathogens were significantly associated with severe gastritis. Importantly, co-infection of H. pylori CagA+/EBV+ had a stronger association with severe MN (PR 3.0 and PMN (PR 7.2 cells than cases with single H. pylori CagA+ infection.Co-infection with EBV and H. pylori in pediatric patients is associated with severe gastritis. Even single infections with H. pylori CagA+ strains are associated with mild to moderate infiltration arguing for a cooperative effect of H. pylori and EBV in the gastric mucosa and revealing a critical role for EBV previously un-appreciated. This study points out the need to study both pathogens to understand the mechanism behind severe damage of the gastric mucosa, which could identified children with increased risk to present more serious lesions later in life.

Detection of Helicobacter pylori virulence factors and interleukin-1 polymorphisms in patients with abdominal complaint

International Nuclear Information System (INIS)

Anarkhuu, B.; Munguntsetseg, B.; Khosbayar, T.; Enkh-Amar, A.; Bayasgalan, P.; Yadamjav, Ch.; Oyuntsetseg, K.; Bira, N.; Choi, P.W.

2007-01-01

Full text: Gastric Cancer is the second leading cause of cancer related death in Mongolia (National Cancer Center, report-2006). Chronic infection with Helicobacter pylori affects approximately half the world and results in malignancy in a small subset of this population. There was sufficient evidence that the Working Group of the International Agency for Research on Cancer (IARC-1994) classified it as a class I carcinogen, the only bacterial agent on this list. The aim of the study is to detect and define the role of H.pylori virulence factors and host IL-1 polymorphisms to prevent further gastric cancer. In the future, this combined bacterial/host genotyping may provide an important opportunity to identify patients who are at high risk for the development of gastric carcinoma long before malignancy occurs. Patients and biopsy specimens. Two biopsy specimens and 5ml of blood samples were collected from each of 59 patients who had abdominal complaint, after informed consent was obtained. All patients lived in Ulaanbaatar, Mongolia, 100% were of Mongolian nationality. Their mean age was 40.33 years (range, 1575 years). One biopsy specimen was used to test urease, and another was stored for molecular testing. DNA isolation from blood and tissue sample was performed with ''Promega'' kit, according to the manufacturer's instruction. Tissue samples were homogenized treated with proteinase K prior to DNA extraction. H. pylori detection and genotyping. For H.pylori, detection was by UreC primer. For virulence gene typing of H.pylori cagA and vacA, gene specific primer were used. Genotyping of IL-1 polymorphisms. IL-1B polymorphisms were distinguished by 2 methods, 5-nuclease PCR assay and restriction fragment length polymorphism analysis (RFLP). Result. Strain characteristics of H. pylori were investigated in all 59 patients. 66,7% (40/59) and 76,3% (29/36) of the patients were infected with H. pylori by UreC PCR and by urea test, respectively. The vacAs1 genotype was

Frecuencia de los genotipos babA2, oipA y cagE de Helicobacter pylori en pacientes colombianos con enfermedades gastroduodenales.

Directory of Open Access Journals (Sweden)

Andrés Javier Quiroga

2005-09-01

Full Text Available Introducción. La infección con Helicobacter pylori está asociada con el desarrollo de diferentes enfermedades gastroduodenales. Varios genes de virulencia de H. pylori se han relacionado con mayor riesgo de enfermedad gástrica. Objetivos. El propósito de este trabajo fue determinar las posibles asociaciones entre la presencia de los genes vacA, cagA, cagE, babA2 y oipA en aislamientos de H. pylori de pacientes colombianos y las diferentes consecuencias clínicas de la infección. Materiales y métodos. Mediante PCR se evaluaron los genotipos cagA, vacA, cagE, oipA y babA2 en 166 aislamientos de H. pylori provenientes de 50 pacientes con úlcera péptica, 39 con gastritis crónica no atrófica, 26 con gastritis crónica atrófica, 26 con metaplasia intestinal y 25 con adenocarcinoma gástrico. Resultados. La frecuencia de los genotipos cagA, cagE, babA2 y oipA fue de 73%, 75%, 48% y 74%, respectivamente. El 64% (100/157 de los aislamientos presentó el genotipo citotóxico vacAs1m1/cagA positivo/cagE positivo. Se observó una mayor frecuencia de cepas citotóxicas en pacientes con cáncer (84%, metaplasia (91% y úlcera (81% en comparación con pacientes con gastritis no atrófica (50% (p=0,002, 0,008 y 0,007, respectivamente. La frecuencia de oipA y babA2 fue mayor en cepas citotóxicas que en cepas no citotóxicas (oipA: 81% vs. 52%, p=0,003; babA2: 58% vs. 12%, p=0,000. No se observaron diferencias significativas en la frecuencia de los genes oipA o babA2 solos o en asociación con vacA y cagA/cagE y las diferentes enfermedades gastroduodenales. Conclusiones. No se encontraron evidencias que sugieran que los genes babA2 u oipA puedan servir como marcadores de ulcerogénesis o carcinogénesis en esta población, solos o en asociación con cagA, cagE o vacA.

CagA+ Helicobacter pylori infection and gastric cancer risk in the EPIC-EURGAST study.

NARCIS (Netherlands)

Palli, D.; Masala, G.; Giudice, G. Del; Plebani, M.; Basso, D.; Berti, D.; Numans, M.E.; Ceroti, M.; Peeters, P.H.; Bueno de Mesquita, H.B.; Buchner, F.L.; Clavel-Chapelon, F.; Boutron-Ruault, M.C.; Krogh, V.; Saieva, C.; Vineis, P.; Panico, S.; Tumino, R.; Nyren, O.; Siman, H.; Berglund, G.; Hallmans, G.; Sanchez, M.J.; Larrañaga, N.; Barricarte, A.; Navarro, C; Quiros, J.R.; Key, T.; Allen, N.; Bingham, S.; Khaw, K.T.; Boeing, H.; Weikert, C.; Linseisen, J.; Nagel, G.; Overvad, K.; Thomsen, R.W.; Tjonneland, A.; Olsen, A.; Trichoupoulou, A.; Trichopoulos, D.; Arvaniti, A.; Pera, G.; Kaaks, R.; Jenab, M.; Ferrari, P.; Nesi, G.; Carneiro, F.; Riboli, E.; Gonzalez, C.A.

2007-01-01

Helicobacter pylori (H. pylori), atrophic gastritis, dietary and life-style factors have been associated with gastric cancer (GC). These factors have been evaluated in a large case-control study nested in the European Prospective Investigation into Cancer and Nutrition carried out in 9 countries,

Multiplex-PCR-Based Screening and Computational Modeling of Virulence Factors and T-Cell Mediated Immunity in Helicobacter pylori Infections for Accurate Clinical Diagnosis.

Directory of Open Access Journals (Sweden)

Sinem Oktem-Okullu

Full Text Available The outcome of H. pylori infection is closely related with bacteria's virulence factors and host immune response. The association between T cells and H. pylori infection has been identified, but the effects of the nine major H. pylori specific virulence factors; cagA, vacA, oipA, babA, hpaA, napA, dupA, ureA, ureB on T cell response in H. pylori infected patients have not been fully elucidated. We developed a multiplex- PCR assay to detect nine H. pylori virulence genes with in a three PCR reactions. Also, the expression levels of Th1, Th17 and Treg cell specific cytokines and transcription factors were detected by using qRT-PCR assays. Furthermore, a novel expert derived model is developed to identify set of factors and rules that can distinguish the ulcer patients from gastritis patients. Within all virulence factors that we tested, we identified a correlation between the presence of napA virulence gene and ulcer disease as a first data. Additionally, a positive correlation between the H. pylori dupA virulence factor and IFN-γ, and H. pylori babA virulence factor and IL-17 was detected in gastritis and ulcer patients respectively. By using computer-based models, clinical outcomes of a patients infected with H. pylori can be predicted by screening the patient's H. pylori vacA m1/m2, ureA and cagA status and IFN-γ (Th1, IL-17 (Th17, and FOXP3 (Treg expression levels. Herein, we report, for the first time, the relationship between H. pylori virulence factors and host immune responses for diagnostic prediction of gastric diseases using computer-based models.

The dynamics of heat shock system activation in Monomac-6 cells upon Helicobacter pylori infection.

Science.gov (United States)

Pierzchalski, P; Jastrzebska, M; Link-Lenczowski, P; Leja-Szpak, A; Bonior, J; Jaworek, J; Okon, K; Wojcik, P

2014-12-01

Immune system cells, particularly phagocytes, are exposed to direct contact with pathogens. Because of its nature - elimination of pathogenes - their cytoprotective systems supposed to be quick and forceful. Physiological consequence of phagocytosis for the phagocyte is the apoptotic death to prevent the eventual survival of bacteria as intracellular parasites. However, in some cases, defense systems used by the bacteria force the immune cells to prolong the contact with the pathogen for its effective elimination. Experiments were performed on Monomac-6 cells exposed to live CagA, VacA expressing Helicobacter pylori (H. pylori) over different period of time. Total cellular RNA, cytoplasmic and nuclear proteins were isolated for polymerase chain reaction, Western-blot and electrophoretic mobility shift assay, respectively. We found that Monomac-6 cells infection with H. pylori resulted in the translocation of the entire cellular content of the heat shock protein 70 (HSP70) into the cytoplasm, where its presence could protect cell against toxic products of engulfed bacteria and premature apoptosis. At the same time the nuclear translocation of heat shock factor 1 (HSF-1) and activation of HSP70 gene transcription was noticed. Action of HSP70 might to postpone monocyte apoptosis through protecting cytoplasmic and nuclear proteins from damaging effect of bacterial products, what could be the defending mechanism against the toxic stress caused by engulfed bacteria and provide the immune cell with the sufficient amount of time required for neutralization of the bacteria from phagosomes, even at the expense of temporary lack of the protection of nuclear proteins.

Positive selection on a bacterial oncoprotein associated with gastric cancer

Directory of Open Access Journals (Sweden)

Delgado-Rosado Gisela

2011-11-01

Full Text Available Background Helicobacter pylori is a vertically inherited gut commensal that is carcinogenic if it possesses the cag pathogenicity island (cag PaI; infection with H.pylori is the major risk factor for gastric cancer, the second leading cause of death from cancer worldwide (WHO. The cag PaI locus encodes the cagA gene, whose protein product is injected into stomach epithelial cells via a Type IV secretion system, also encoded by the cag PaI. Once there, the cagA protein binds to various cellular proteins, resulting in dysregulation of cell division and carcinogenesis. For this reason, cagA may be described as an oncoprotein. A clear understanding of the mechanism of action of cagA and its benefit to the bacteria is lacking. Results Here, we reveal that the cagA gene displays strong signatures of positive selection in bacteria isolated from amerindian populations, using the Ka/Ks ratio. Weaker signatures are also detected in the gene from bacteria isolated from asian populations, using the Ka/Ks ratio and the more sensitive branches-sites model of the PAML package. When the cagA gene isolated from amerindian populations was examined in more detail it was found that the region under positive selection contains the EPIYA domains, which are known to modulate the carcinogenicity of the gene. This means that the carcinogenicity modulating region of the gene is undergoing adaptation. The results are discussed in relation to the high incidences of stomach cancer in some latin american and asian populations. Conclusion Positive selection on cagA indicates antagonistic coevolution between host and bacteria, which appears paradoxical given that cagA is detrimental to the human host upon which the bacteria depends. This suggests several non-exclusive possibilities; that gastric cancer has not been a major selective pressure on human populations, that cagA has an undetermined benefit to the human host, or that horizontal transmission of H.pylori between hosts

Pathobiology of Helicobacter pylori-induced Gastric Cancer

Science.gov (United States)

Amieva, Manuel; Peek, Richard M.

2015-01-01

Colonization of the human stomach by Helicobacter pylori and its role in causing gastric cancer is one of the richest examples of complex relationship among human cells, microbes, and their environment. It is also a puzzle of enormous medical importance given the incidence and lethality of gastric cancer worldwide. We review recent findings that have changed how we view these relationships and affected the direction of gastric cancer research. For example, recent data indicate that subtle mismatches between host and microbe genetic traits greatly affect risk of gastric cancer. The ability of H pylori and its oncoprotein CagA to reprogram epithelial cells and activate properties of stemness demonstrates the sophisticated relationship among H pylori and progenitor cells in the gastric mucosa. The observation that cell-associated H pylori can colonize the gastric glands and directly affect precursor and stem cells supports these observations. The ability to mimic these interactions in human gastric organoid cultures as well as animal models will allow investigators to more fully unravel the extent of H pylori control on the renewing gastric epithelium. Finally, our realization that external environmental factors, such as dietary components and essential micronutrients, as well as the gastrointestinal microbiota, can change the balance between H pylori’s activity as a commensal or a pathogen has provided direction to studies aimed at defining the full carcinogenic potential of this organism. PMID:26385073

The Helicobacter pylori duodenal ulcer promoting gene, dupA in China

Directory of Open Access Journals (Sweden)

Liu Wenzhong

2008-10-01

Full Text Available Abstract Background The prevalence of H. pylori is as high as 60–70% in Chinese population. Although duodenal ulcer and gastric cancer are both caused by H. pylori, they are at opposite ends of the spectrum and as such are considered mutually exclusive. Duodenal ulcer promoting (dupA gene was reported to be associated with duodenal ulcer development. The aim of this study was to determine the prevalence of dupA gene of Helicobacter pylori in patients with various gastroduodenal diseases and to explore the association between the gene and other virulence factors. Methods H. pylori were isolated from gastric biopsies of patients with chronic gastritis, duodenal ulcer (DU, gastric ulcer (GU, or non-cardia gastric carcinoma. The dupA, cagA, vacA, iceA and babA2 genotypes were determined by polymerase chain reaction. Histological features of gastric mucosal biopsy specimens were graded based on the scoring system proposed by the updated Sydney system. IL-1β polymorphism was investigated using restriction fragment length polymorphism. Results Isolates from 360 patients including 133 with chronic gastritis, 101 with DU, 47 with GU, and 79 with non-cardia gastric carcinoma were examined. The dupA gene was detected in 35.3% (127/360 and the prevalence DU patients was significantly greater than that in gastric cancer or GU patients (45.5% vs. 24.1% and 23.4%, P dupA-positive strains had higher scores for chronic inflammation compared to those with dupA-negative strains (2.36 vs. 2.24, p = 0.058. The presence of dupA was not associated with the cagA, vacA, iceA and babA 2 genotypes or with IL-1β polymorphisms. Conclusion In China the prevalence of dupA gene was highest in DU and inversely related to GU and gastric cancer.

The Helicobacter pylori duodenal ulcer promoting gene, dupA in China.

Science.gov (United States)

Zhang, Zhiyu; Zheng, Qing; Chen, Xiaoyu; Xiao, Shudong; Liu, Wenzhong; Lu, Hong

2008-10-25

The prevalence of H. pylori is as high as 60-70% in Chinese population. Although duodenal ulcer and gastric cancer are both caused by H. pylori, they are at opposite ends of the spectrum and as such are considered mutually exclusive. Duodenal ulcer promoting (dupA) gene was reported to be associated with duodenal ulcer development. The aim of this study was to determine the prevalence of dupA gene of Helicobacter pylori in patients with various gastroduodenal diseases and to explore the association between the gene and other virulence factors. H. pylori were isolated from gastric biopsies of patients with chronic gastritis, duodenal ulcer (DU), gastric ulcer (GU), or non-cardia gastric carcinoma. The dupA, cagA, vacA, iceA and babA2 genotypes were determined by polymerase chain reaction. Histological features of gastric mucosal biopsy specimens were graded based on the scoring system proposed by the updated Sydney system. IL-1beta polymorphism was investigated using restriction fragment length polymorphism. Isolates from 360 patients including 133 with chronic gastritis, 101 with DU, 47 with GU, and 79 with non-cardia gastric carcinoma were examined. The dupA gene was detected in 35.3% (127/360) and the prevalence DU patients was significantly greater than that in gastric cancer or GU patients (45.5% vs. 24.1% and 23.4%, P dupA-positive strains had higher scores for chronic inflammation compared to those with dupA-negative strains (2.36 vs. 2.24, p = 0.058). The presence of dupA was not associated with the cagA, vacA, iceA and babA 2 genotypes or with IL-1beta polymorphisms. In China the prevalence of dupA gene was highest in DU and inversely related to GU and gastric cancer.

Inhibition of Helicobacter pylori CagA-Induced Pathogenesis by Methylantcinate B from Antrodia camphorata

Directory of Open Access Journals (Sweden)

Chun-Jung Lin

2013-01-01

Full Text Available The bacterial pathogen Helicobacter pylori (Hp is the leading risk factor for the development of gastric cancer. Hp virulence factor, cytotoxin-associated gene A (CagA interacted with cholesterol-enriched microdomains and leads to induction of inflammation in gastric epithelial cells (AGS. In this study, we identified a triterpenoid methylantcinate B (MAB from the medicinal mushroom Antrodia camphoratawhich inhibited the translocation and phosphorylation of CagA and caused a reduction in hummingbird phenotype in HP-infected AGS cells. Additionally, MAB suppressed the Hp-induced inflammatory response by attenuation of NF-κB activation, translocation of p65 NF-κB, and phosphorylation of IκB-α, indicating that MAB modulates CagA-mediated signaling pathway. Additionally, MAB also suppressed the IL-8 luciferase activity and its secretion in HP-infected AGS cells. On the other hand, molecular structure simulations revealed that MAB interacts with CagA similarly to that of cholesterol. Moreover, binding of cholesterol to the immobilized CagA was inhibited by increased levels of MAB. Our results demonstrate that MAB is the first natural triterpenoid which competes with cholesterol bound to CagA leading to attenuation of Hp-induced pathogenesis of epithelial cells. Thus, this study indicates that MAB may have a scope to develop as a therapeutic candidate against Hp CagA-induced inflammation.

Helicobacter pylori genotypes and types of gastritis in first-degree relatives of gastric cancer patients.

Science.gov (United States)

Siavoshi, F; Asgharzadeh, A; Ghadiri, H; Massarrat, S; Latifi-Navid, S; Zamani, M

2011-08-01

The frequency of Helicobacter pylori vacA alleles, cagA, and jhp0947 and their association with types and advanced forms of gastritis in 143 first-degree relatives of gastric cancer (GC) patients was assessed. The subjects included 64/143 with antral-predominant gastritis, 68/143 with pangastritis, and 11/143 with corpus-predominant gastritis, with or without atrophy or intestinal metaplasia (IM). Further classification included the severity of atrophy or IM. Group I (40/143) included the subjects with moderate-marked atrophy or IM, group II (58/143) those with no atrophy or IM, and group III (45/143) with mild atrophy or IM. The frequency of vacA s1 was 79.7%, vacA s2 20.3%, m1 49.7%, m2 50.3%, cagA 76.2%, and jhp0947 58%. The most prevalent combination was vacAs1 cagA (+) (65.7%) (P=0.001). Of the 143 subjects, 85 (59.4%) showed atrophy or IM, and 40/85 (47%) developed the moderate-marked atrophy or IM. No significant correlation was found between genotypes and the types of gastritis, non-atrophy, atrophy, or IM and severe forms of atrophy or IM (P>0.05). It is proposed that H. pylori genotype status might not be considered as an important determinant of the types and advanced forms of gastritis in the first-degree relatives of GC patients. Copyright © 2011 Elsevier GmbH. All rights reserved.

CagA and VacA Helicobacter Pylori Antibodies in Gastric Cancer

Directory of Open Access Journals (Sweden)

Renzo Suriani

2008-01-01

Full Text Available BACKGROUND: Infection with different genotypes of virulent Helicobacter pylori strains (cytotoxin-associated gene A [CagA]-and/or vacuolating cytotoxin A [VacA]-positive can play a role in the development of atrophic gastritis, duodenal ulcer (DU and gastric cancer (GC.

Persistent colonization of Helicobacter pylori in human gut induces gastroduodenal diseases

Directory of Open Access Journals (Sweden)

Animesh Sarker

2014-12-01

Full Text Available Helicobacter pylori are gut bacteria colonize in the epithelial cell lining of the stomach and persist there for long du­ration. Around two-thirds of the world’s populations are infected with H. pylori and cause more than 90 percent of ulcers. The development of persistent inflammation is the main cause of chronic gastritis that finally results in a severe consequence known as stomach cancer. Two major virulence factors cytotoxin-associated gene product (cagA and the vacuolating toxin (vacA are mostly investigated as their close association with gastric carcinoma. In this review, host im­munity against H. pylori infection and their evasion mechanism are intensely explored. It is the fact, that understanding pin point molecular mechanisms of any infection is critical to develop novel strategies to prevent pertinent diseases. .J Microbiol Infect Dis 2014; 4(4: 170-176

Helicobacter pylori virulence and cancer pathogenesis.

Science.gov (United States)

Yamaoka, Yoshio; Graham, David Y

2014-06-01

Helicobacter pylori is human gastric pathogen that causes chronic and progressive gastric mucosal inflammation and is responsible for the gastric inflammation-associated diseases, gastric cancer and peptic ulcer disease. Specific outcomes reflect the interplay between host-, environmental- and bacterial-specific factors. Progress in understanding putative virulence factors in disease pathogenesis has been limited and many false leads have consumed scarce resources. Few in vitro-in vivo correlations or translational applications have proved clinically relevant. Reported virulence factor-related outcomes reflect differences in relative risk of disease rather than specificity for any specific outcome. Studies of individual virulence factor associations have provided conflicting results. Since virulence factors are linked, studies of groups of putative virulence factors are needed to provide clinically useful information. Here, the authors discuss the progress made in understanding the role of H. pylori virulence factors CagA, vacuolating cytotoxin, OipA and DupA in disease pathogenesis and provide suggestions for future studies.

Frequency of virulence genes in mixed infections with Helicobacter pylori strains from a Mexican population

Directory of Open Access Journals (Sweden)

R. González-Vázquez

2016-01-01

Conclusions: The Fisher's exact test did not support a significant association between clinical outcome and genotype. The main circulating genotypes in the Mexican population studied were: cagA+, vacAs1, and vacAm1. Multiplex PCR can be used as a screening test for H. pylori strains. Furthermore, the cagE gene is a good marker for identifying cag-PAI positive strains.

Alterations in Helicobacter pylori triggered by contact with gastric epithelial cells

Directory of Open Access Journals (Sweden)

Elizabeth M. Johnson

2012-02-01

Full Text Available Helicobacter pylori lives within the mucus layer of the human stomach, in close proximity to gastric epithelial cells. While a great deal is known about the effects of H. pylori on human cells and the specific bacterial products that mediate these effects, relatively little work has been done to investigate alterations in H. pylori that may be triggered by bacterial contact with human cells. In this review, we discuss the spectrum of changes in bacterial physiology and morphology that occur when H. pylori is in contact with gastric epithelial cells. Several studies have reported that cell contact causes alterations in H. pylori gene transcription. In addition, H. pylori contact with gastric epithelial cells promotes the formation of pilus-like structures at the bacteria-host cell interface. The formation of these structures requires multiple genes in the cag pathogenicity island, and these structures are proposed to have an important role in the type IV secretion system-dependent process through which CagA enters host cells. Finally, H. pylori contact with epithelial cells can promote bacterial replication and the formation of microcolonies, phenomena that are facilitated by the acquisition of iron and other nutrients from infected cells. In summary, the gastric epithelial cell surface represents an important niche for H. pylori, and upon entry into this niche, the bacteria alter their behavior in a manner that optimizes bacterial proliferation and persistent colonization of the host.

Genetic fine structure analysis of helicobacter pylori isolates before and after treatment

Directory of Open Access Journals (Sweden)

Rekha T

2003-01-01

Full Text Available BACKGROUND: Eradication of H. pylori infection cures peptic ulcer disease and conversely, relapse is associated with reappearance of H. pylori infection. However, it is not clear whether the recurrence of ulcers following H. pylori eradication is due to recrudescence (identical strain of the previous infection or as a result of exogenous reinfection (different strain by another strain. The aim of the present study was to analyze the FAFLP patterns of pre and post treatment H. pylori samples to check if the recurrence was due to recrudescence or reinfection. MATERIALS AND METHODS: 24 of 30 duodenal ulcer (DU subjects screened for H. pylori infection were positive for H. pylori infection. The treatment regime included pantoprazole, ciprofloxacin and amoxicillin. The patients were called for a repeat endoscopy after one month and screened for H. pylori infection. FAFLP analysis and PCR for the cagA and vacA gene was performed for the pre and post treatment samples. RESULTS: Of the 24 positive H.pylori patients, only 6 were negative after treatment and the remaining 18 were positive for H.pylori infection. The analysis of the pre and post treatment samples of the 18 patients showed that the FAFLP profiles of the initial and follow-up pools were similar to one another. CONCLUSION: It can be concluded that in the present series of patients, reinfection was due to recrudescence of infection due to incomplete eradication. The study also suggests that DNA fingerprinting by FAFLP provides discriminatory and complementary data for identifying strains of H. pylori while monitoring therapy.

CagI is an essential component of the Helicobacter pylori Cag type IV secretion system and forms a complex with CagL.

Directory of Open Access Journals (Sweden)

Kieu Thuy Pham

Full Text Available Helicobacter pylori, the causative agent of type B gastritis, peptic ulcers, gastric adenocarcinoma and MALT lymphoma, uses the Cag type IV secretion system to induce a strong proinflammatory response in the gastric mucosa and to inject its effector protein CagA into gastric cells. CagA translocation results in altered host cell gene expression profiles and cytoskeletal rearrangements, and it is considered as a major bacterial virulence trait. Recently, it has been shown that binding of the type IV secretion apparatus to integrin receptors on target cells is a crucial step in the translocation process. Several bacterial proteins, including the Cag-specific components CagL and CagI, have been involved in this interaction. Here, we have examined the localization and interactions of CagI in the bacterial cell. Since the cagI gene overlaps and is co-transcribed with the cagL gene, the role of CagI for type IV secretion system function has been difficult to assess, and conflicting results have been reported regarding its involvement in the proinflammatory response. Using a marker-free gene deletion approach and genetic complementation, we show now that CagI is an essential component of the Cag type IV secretion apparatus for both CagA translocation and interleukin-8 induction. CagI is distributed over soluble and membrane-associated pools and seems to be partly surface-exposed. Deletion of several genes encoding essential Cag components has an impact on protein levels of CagI and CagL, suggesting that both proteins require partial assembly of the secretion apparatus. Finally, we show by co-immunoprecipitation that CagI and CagL interact with each other. Taken together, our results indicate that CagI and CagL form a functional complex which is formed at a late stage of secretion apparatus assembly.

Helicobacter pylori dupA is polymorphic, and its active form induces proinflammatory cytokine secretion by mononuclear cells.

Science.gov (United States)

Hussein, Nawfal R; Argent, Richard H; Marx, Christian K; Patel, Sapna R; Robinson, Karen; Atherton, John C

2010-07-15

Infection with Helicobacter pylori possessing a newly described virulence factor--duodenal ulcer-promoting gene A (dupA)--has been associated with duodenal ulceration and increased gastric inflammation. The dupA locus of 34 strains was sequenced. A panel of dupA mutants was generated and cocultured with human gastric epithelial cells and peripheral blood mononuclear cells; proinflammatory cytokine release was measured. IL8 expression was measured in human gastric biopsy specimens and related to the dupA and cagA status of infecting strains. Most H. pylori strains had a dupA allele that was longer (1884 bp; dupA1) than previously described dupA alleles, although some had truncated versions (dupA2). Unlike the best-characterized H. pylori virulence determinant, the cag pathogenicity island (cag PaI), neither dupA type induced release of interleukin (IL)-8 from gastric epithelial cells. However, infections due to dupA-positive strains were associated with higher-level mucosal IL-8 messenger RNA expression in the human stomach than were infections due to dupA-negative strains. To explain this paradox, we found that dupA1 (but not dupA2 or the cag PaI) substantially increased H. pylori-induced IL-12p40 and IL-12p70 production from CD14(+) mononuclear cells. Other T helper 1-associated cytokines were also modestly induced. We suggest that virulent H. pylori strains cause inflammation by stimulating epithelial cells through cag-encoded proteins and mononuclear inflammatory cells through dupA1 products.

Infection with CagA-positive Helicobacter pylori strain containing three EPIYA C phosphorylation sites is associated with more severe gastric lesions in experimentally infected Mongolian gerbils (Meriones unguiculatus).

Science.gov (United States)

Ferreira Júnior, M; Batista, S A; Vidigal, P V T; Cordeiro, A A C; Oliveira, F M S; Prata, L O; Diniz, A E T; Barral, C M; Barbuto, R C; Gomes, A D; Araújo, I D; Queiroz, D M M; Caliari, M V

2015-04-27

Infection with Helicobacter pylori strains containing high number of EPIYA-C phosphorylation sites in the CagA is associated with significant gastritis and increased risk of developing pre-malignant gastric lesions and gastric carcinoma. However, these findings have not been reproduced in animal models yet. Therefore, we investigated the effect on the gastric mucosa of Mongolian gerbil (Meriones unguiculatus) infected with CagA-positive H. pylori strains exhibiting one or three EPIYA-C phosphorilation sites. Mongolian gerbils were inoculated with H. pylori clonal isolates containing one or three EPIYA-C phosphorylation sites. Control group was composed by uninfected animals challenged with Brucella broth alone. Gastric fragments were evaluated by the modified Sydney System and digital morphometry. Clonal relatedness between the isolates was considered by the identical RAPD-PCR profiles and sequencing of five housekeeping genes, vacA i/d region and of oipA. The other virulence markers were present in both isolates (vacA s1i1d1m1, iceA2, and intact dupA). CagA of both isolates was translocated and phosphorylated in AGS cells. After 45 days of infection, there was a significant increase in the number of inflammatory cells and in the area of the lamina propria in the infected animals, notably in those infected by the CagA-positive strain with three EPIYA-C phosphorylation sites. After six months of infection, a high number of EPIYA-C phosphorylation sites was associated with progressive increase in the intensity of gastritis and in the area of the lamina propria. Atrophy, intestinal metaplasia, and dysplasia were also observed more frequently in animals infected with the CagA-positive isolate with three EPIYA-C sites.  We conclude that infection with H. pylori strain carrying a high number of CagA EPIYA-C phosphorylation sites is associated with more severe gastric lesions in an animal model of H. pylori infection.

Infection with CagA-positive Helicobacter pylori strain containing three EPIYA C phosphorylation sites is associated with more severe gastric lesions in experimentally infected Mongolian gerbils (Meriones unguiculatus

Directory of Open Access Journals (Sweden)

M. Ferreira Júnior

2015-04-01

Full Text Available Infection with Helicobacter pylori strains containing high number of EPIYA-C phosphorylation sites in the CagA is associated with significant gastritis and increased risk of developing pre-malignant gastric lesions and gastric carcinoma. However, these findings have not been reproduced in animal models yet. Therefore, we investigated the effect on the gastric mucosa of Mongolian gerbil (Meriones unguiculatus infected with CagA-positive H. pylori strains exhibiting one or three EPIYA-C phosphorilation sites. Mongolian gerbils were inoculated with H. pylori clonal isolates containing one or three EPIYA-C phosphorylation sites. Control group was composed by uninfected animals challenged with Brucella broth alone. Gastric fragments were evaluated by the modified Sydney System and digital morphometry. Clonal relatedness between the isolates was considered by the identical RAPD-PCR profiles and sequencing of five housekeeping genes, vacA i/d region and of oipA. The other virulence markers were present in both isolates (vacA s1i1d1m1, iceA2, and intact dupA. CagA of both isolates was translocated and phosphorylated in AGS cells. After 45 days of infection, there was a significant increase in the number of inflammatory cells and in the area of the lamina propria in the infected animals, notably in those infected by the CagA-positive strain with three EPIYA-C phosphorylation sites. After six months of infection, a high number of EPIYA-C phosphorylation sites was associated with progressive increase in the intensity of gastritis and in the area of the lamina propria. Atrophy, intestinal metaplasia, and dysplasia were also observed more frequently in animals infected with the CagA-positive isolate with three EPIYA-C sites.  We conclude that infection with H. pylori strain carrying a high number of CagA EPIYA-C phosphorylation sites is associated with more severe gastric lesions in an animal model of H. pylori infection.

A designated centre for people with disabilities operated by Nua Healthcare Services, Clare

LENUS (Irish Health Repository)

Backert, Steffen

2011-11-01

Abstract Helicobacter pylori is a highly successful pathogen uniquely adapted to colonize humans. Gastric infections with this bacterium can induce pathology ranging from chronic gastritis and peptic ulcers to gastric cancer. More virulent H. pylori isolates harbour numerous well-known adhesins (BabA\\/B, SabA, AlpA\\/B, OipA and HopZ) and the cag (cytotoxin-associated genes) pathogenicity island encoding a type IV secretion system (T4SS). The adhesins establish tight bacterial contact with host target cells and the T4SS represents a needle-like pilus device for the delivery of effector proteins into host target cells such as CagA. BabA and SabA bind to blood group antigen and sialylated proteins respectively, and a series of T4SS components including CagI, CagL, CagY and CagA have been shown to target the integrin β1 receptor followed by injection of CagA across the host cell membrane. The interaction of CagA with membrane-anchored phosphatidylserine may also play a role in the delivery process. While substantial progress has been made in our current understanding of many of the above factors, the host cell receptors for OipA, HopZ and AlpA\\/B during infection are still unknown. Here we review the recent progress in characterizing the interactions of the various adhesins and structural T4SS proteins with host cell factors. The contribution of these interactions to H. pylori colonization and pathogenesis is discussed.

Ulcerogenic Helicobacter pylori strains isolated from children: a contribution to get insight into the virulence of the bacteria.

Directory of Open Access Journals (Sweden)

Inês Vitoriano

Full Text Available Infection with Helicobacter pylori is the major cause for the development of peptic ulcer disease (PUD. In children, with no other etiology for the disease, this rare event occurs shortly after infection. In these young patients, habits of smoking, diet, consumption of alcohol and non-steroid anti-inflammatory drugs and stress, in addition to the genetic susceptibility of the patient, represent a minor influence. Accordingly, the virulence of the implicated H. pylori strain should play a crucial role in the development of PUD. Corroborating this, our in vitro infection assays comparing a pool of five H. pylori strains isolated from children with PUD to a pool of five other pediatric clinical isolates associated with non-ulcer dyspepsia (NUD showed the greater ability of PUD strains to induce a marked decrease in the viability of gastric cells and to cause severe damage in the cells cytoskeleton as well as an impairment in the production/secretion of mucins. To uncover virulence features, we compared the proteome of these two groups of H. pylori strains. Two-dimensional gel electrophoresis followed by mass-spectrometry allowed us to detect 27 differentially expressed proteins between them. In addition to the presence of genes encoding well established virulence factors, namely cagA, vacAs1, oipA "on" status, homB and jhp562 genes, the pediatric ulcerogenic strains shared a proteome profile characterized by changes in the abundance of: motility-associated proteins, accounting for higher motility; antioxidant proteins, which may confer increased resistance to inflammation; and enzymes involved in key steps in the metabolism of glucose, amino acids and urea, which may be advantageous to face fluctuations of nutrients. In conclusion, the enhanced virulence of the pediatric ulcerogenic H. pylori strains may result from a synergy between their natural ability to better adapt to the hostile human stomach and the expression of the established virulence

Chemokines and antimicrobial peptides have a cag-dependent early response to Helicobacter pylori infection in primary human gastric epithelial cells.

Science.gov (United States)

Mustapha, Pascale; Paris, Isabelle; Garcia, Magali; Tran, Cong Tri; Cremniter, Julie; Garnier, Martine; Faure, Jean-Pierre; Barthes, Thierry; Boneca, Ivo G; Morel, Franck; Lecron, Jean-Claude; Burucoa, Christophe; Bodet, Charles

2014-07-01

Helicobacter pylori infection systematically causes chronic gastric inflammation that can persist asymptomatically or evolve toward more severe gastroduodenal pathologies, such as ulcer, mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric cancer. The cag pathogenicity island (cag PAI) of H. pylori allows translocation of the virulence protein CagA and fragments of peptidoglycan into host cells, thereby inducing production of chemokines, cytokines, and antimicrobial peptides. In order to characterize the inflammatory response to H. pylori, a new experimental protocol for isolating and culturing primary human gastric epithelial cells was established using pieces of stomach from patients who had undergone sleeve gastrectomy. Isolated cells expressed markers indicating that they were mucin-secreting epithelial cells. Challenge of primary epithelial cells with H. pylori B128 underscored early dose-dependent induction of expression of mRNAs of the inflammatory mediators CXCL1 to -3, CXCL5, CXCL8, CCL20, BD2, and tumor necrosis factor alpha (TNF-α). In AGS cells, significant expression of only CXCL5 and CXCL8 was observed following infection, suggesting that these cells were less reactive than primary epithelial cells. Infection of both cellular models with H. pylori B128ΔcagM, a cag PAI mutant, resulted in weak inflammatory-mediator mRNA induction. At 24 h after infection of primary epithelial cells with H. pylori, inflammatory-mediator production was largely due to cag PAI substrate-independent virulence factors. Thus, H. pylori cag PAI substrate appears to be involved in eliciting an epithelial response during the early phases of infection. Afterwards, other virulence factors of the bacterium take over in development of the inflammatory response. Using a relevant cellular model, this study provides new information on the modulation of inflammation during H. pylori infection. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Exploiting the Gastric Epithelial Barrier: Helicobacter pylori's Attack on Tight and Adherens Junctions.

Science.gov (United States)

Backert, Steffen; Schmidt, Thomas P; Harrer, Aileen; Wessler, Silja

2017-01-01

Highly organized intercellular tight and adherens junctions are crucial structural components for establishing and maintenance of epithelial barrier functions, which control the microbiota and protect against intruding pathogens in humans. Alterations in these complexes represent key events in the development and progression of multiple infectious diseases as well as various cancers. The gastric pathogen Helicobacter pylori exerts an amazing set of strategies to manipulate these epithelial cell-to-cell junctions, which are implicated in changing cell polarity, migration and invasive growth as well as pro-inflammatory and proliferative responses. This chapter focuses on the H. pylori pathogenicity factors VacA, CagA, HtrA and urease, and how they can induce host cell signaling involved in altering cell-to-cell permeability. We propose a stepwise model for how H. pylori targets components of tight and adherens junctions in order to disrupt the gastric epithelial cell layer, giving fresh insights into the pathogenesis of this important bacterium.

Role of microRNAs and Exosomes in Helicobacter pylori and Epstein-Barr Virus Associated Gastric Cancers

Science.gov (United States)

Polakovicova, Iva; Jerez, Sofia; Wichmann, Ignacio A.; Sandoval-Bórquez, Alejandra; Carrasco-Véliz, Nicolás; Corvalán, Alejandro H.

2018-01-01

Emerging evidence suggests that chronic inflammation caused by pathogen infection is connected to the development of various types of cancer. It is estimated that up to 20% of all cancer deaths is linked to infections and inflammation. In gastric cancer, such triggers can be infection of the gastric epithelium by either Helicobacter pylori (H. pylori), a bacterium present in half of the world population; or by Epstein-Barr virus (EBV), a double-stranded DNA virus which has recently been associated with gastric cancer. Both agents can establish lifelong inflammation by evolving to escape immune surveillance and, under certain conditions, contribute to the development of gastric cancer. Non-coding RNAs, mainly microRNAs (miRNAs), influence the host innate and adaptive immune responses, though long non-coding RNAs and viral miRNAs also alter these processes. Reports suggest that chronic infection results in altered expression of host miRNAs. In turn, dysregulated miRNAs modulate the host inflammatory immune response, favoring bacterial survival and persistence within the gastric mucosa. Given the established roles of miRNAs in tumorigenesis and innate immunity, they may serve as an important link between H. pylori- and EBV-associated inflammation and carcinogenesis. Example of this is up-regulation of miR-155 in H. pylori and EBV infection. The tumor environment contains a variety of cells that need to communicate with each other. Extracellular vesicles, especially exosomes, allow these cells to deliver certain type of information to other cells promoting cancer growth and metastasis. Exosomes have been shown to deliver not only various types of genetic information, mainly miRNAs, but also cytotoxin-associated gene A (CagA), a major H. pylori virulence factor. In addition, a growing body of evidence demonstrates that exosomes contain genetic material of viruses and viral miRNAs and proteins such as EBV latent membrane protein 1 (LMP1) which are delivered into

Role of microRNAs and Exosomes in Helicobacter pylori and Epstein-Barr Virus Associated Gastric Cancers

Directory of Open Access Journals (Sweden)

Iva Polakovicova

2018-04-01

Full Text Available Emerging evidence suggests that chronic inflammation caused by pathogen infection is connected to the development of various types of cancer. It is estimated that up to 20% of all cancer deaths is linked to infections and inflammation. In gastric cancer, such triggers can be infection of the gastric epithelium by either Helicobacter pylori (H. pylori, a bacterium present in half of the world population; or by Epstein-Barr virus (EBV, a double-stranded DNA virus which has recently been associated with gastric cancer. Both agents can establish lifelong inflammation by evolving to escape immune surveillance and, under certain conditions, contribute to the development of gastric cancer. Non-coding RNAs, mainly microRNAs (miRNAs, influence the host innate and adaptive immune responses, though long non-coding RNAs and viral miRNAs also alter these processes. Reports suggest that chronic infection results in altered expression of host miRNAs. In turn, dysregulated miRNAs modulate the host inflammatory immune response, favoring bacterial survival and persistence within the gastric mucosa. Given the established roles of miRNAs in tumorigenesis and innate immunity, they may serve as an important link between H. pylori- and EBV-associated inflammation and carcinogenesis. Example of this is up-regulation of miR-155 in H. pylori and EBV infection. The tumor environment contains a variety of cells that need to communicate with each other. Extracellular vesicles, especially exosomes, allow these cells to deliver certain type of information to other cells promoting cancer growth and metastasis. Exosomes have been shown to deliver not only various types of genetic information, mainly miRNAs, but also cytotoxin-associated gene A (CagA, a major H. pylori virulence factor. In addition, a growing body of evidence demonstrates that exosomes contain genetic material of viruses and viral miRNAs and proteins such as EBV latent membrane protein 1 (LMP1 which are

Helicobacter pylori virulence genes in the five largest islands of Indonesia.

Science.gov (United States)

Miftahussurur, Muhammad; Syam, Ari Fahrial; Makmun, Dadang; Nusi, Iswan Abbas; Zein, Lukman Hakim; Zulkhairi; Akil, Fardah; Uswan, Willi Brodus; Simanjuntak, David; Uchida, Tomohisa; Adi, Pangestu; Utari, Amanda Pitarini; Rezkitha, Yudith Annisa Ayu; Subsomwong, Phawinee; Nasronudin; Yamaoka, Yoshio

2015-01-01

It remains unclear whether the low incidence of gastric cancer in Indonesia is due to low infection rates only or is also related to low Helicobacter pylori pathogenicity. We collected H. pylori strains from the five largest islands in Indonesia and evaluated genetic virulence factors. The genotypes of H. pylori virulence factors were determined by polymerase chain reaction (PCR)-based sequencing. Histological severity of the gastric mucosa was classified into 4 grades, according to the updated Sydney system. A total of 44 strains were analyzed. Forty-three (97.7 %) were cagA-positive: 26 (60.5 %) were East-Asian-type-cagA, 9 (20.9 %) were Western-type-cagA, and 8 (18.6 %) were novel ABB-type, most of which were obtained from Papuan. EPIYT sequences were more prevalent than EPIYA sequences (P = 0.01) in the EPIYA-B motif of all types of cagA. The majority of cagA-positive strains (48.8 %, 21/43) had a 6-bp deletion in the first pre-EPIYA region. Subjects infected with East-Asian-type-cagA strains with a 6-bp deletion had significantly lower inflammation and atrophy scores in the corpus than those infected with Western-type-cagA strains (both P = 0.02). In total, 70.4 % of strains possessed the vacA s1m1 genotype and 29.5 % were m2. All strains from peptic ulcer patients were of the iceA1 genotype, which occurred at a significantly higher proportion in peptic ulcer patients than that in gastritis patients (55.3 %, P = 0.04). The double positive genotype of jhp0562/β-(1,3)galT was predominant (28/44, 63.6 %), and subjects infected with this type had significantly higher inflammation scores in the corpus than those with the jhp0562 negative/β-(1,3)galT positive genotype (mean [median]; 1.43 [1] vs. 0.83 [1], P = 0.04). There were significant differences in cagA and pre-EPIYA cagA type, oipA status, and jhp0562/β-(1,3)galT type among different ethnic groups (P dupA negative or short type dupA, and the jhp0562/β-(1,3)galT double positive genotype.

Association between interleukin-1 β polymorphisms and gastric disease in children: A correlation with Helicobacter pylori

Directory of Open Access Journals (Sweden)

Luanna Munhoz Zabaglia

2016-09-01

Full Text Available Objective: To investigate an association between the interleukin-1β (IL-1β -511 T>C (rs16944, -31 C>T (rs1143627, and/or interleukin-1 receptor antagonist (IL-1RA polymorphisms and gastritis and then to correlate any associations with the presence of Helicobacter pylori (H. pylori, cagA and vacA genes. Methods: Gastric biopsies were obtained from 377 children with gastric symptoms including 152 males and 225 females aging from 1–15 years with the mean age of (9.41 ± 4.29 years. To characterize the -511 T>C, -31 C>T, and IL-1RA polymorphisms, the PCR-RFLP and PCRVNTR methods were used. PCR was also used for the diagnosis of H. pylori and to determine whether cagA and vacA genes were present. Results: The histopathological analysis revealed 206 patients (54.6% with gastritis and 171 patients (45.4% with normal gastric tissue. Subjects carrying the -511 T/T genotype were associated with a risk of gastritis (odds ratio (OR = 2.75, 95% confidence interval (CI 1.45– 5.18, P = 0.0035. Similar results were found in subjects carrying -31 C/C (OR= 2.27, 95% CI 1.13–4.54, P = 0.0440. However, the IL-1RA polymorphism did not seem to be associated with gastric disease (OR= 1.38, 95% CI 0.58–3.26, P = 0.2400. Conclusions: This data suggests that IL-1β gene cluster polymorphisms and, more specifically, interactions between these polymorphisms and H. pylori may be predictors of gastritis risks, which possibly play a relevant role in the susceptibility to or the development of gastric disease early in life.

Detection of Helicobacter pylori vacA, cagA and iceA1 virulence ...

African Journals Online (AJOL)

Ahmed El-Shenawy

related genes in different age group patients with ... vacA and iceA1 genotypes of H. pylori strains recovered from patients with dyspepsia. Subjects and methods: ..... many decades in the absence of antimicrobial treatment. Longitu- dinal studies ...

Plasticity Region Genes jhp0940, jhp0945, jhp0947, and jhp0949 of Helicobacter pylori in Isolates from Mexican Children.

Science.gov (United States)

Romo-González, Carolina; Consuelo-Sánchez, Alejandra; Camorlinga-Ponce, Margarita; Velázquez-Guadarrama, Norma; García-Zúñiga, Magdalena; Burgueño-Ferreira, Juan; Coria-Jiménez, Rafael

2015-06-01

The genes jhp0940, jhp0945, jhp0947, and jhp0949 belong to the plasticity region of the Helicobacter pylori genome. Due to their prevalence in isolates from patients with gastritis, duodenal ulcer, and gastric cancer, they have been proposed as markers of gastroduodenal diseases. These genes are associated with pro-inflammatory cytokine induction through the NF-κB activation pathway. Nevertheless, the status of these genes is unknown in H. pylori isolates from children. The aim of the present work was to determine the frequency of the jhp0940-jhp0945-jhp0947-jhp0949 genes in H. pylori isolates from children. We identified the jhp0940, jhp0945, jhp0947, and jhp0949 genes and the relationship of each with the virulence factors cagA, cagPAI, and dupA by PCR in 49 isolates of H. pylori from children. The results were corroborated using dot blots. In addition, we compared the prevalence of these genes with the prevalence in adults. The prevalence of jhp0940 (53.1%), jhp0945 (44.9%), jhp0947 (77.6%), and jhp0949 (83.7%) was determined in the isolates from children, as was the prevalence of the virulence genes cagA (63.3%), cagPAI (71.4%), and dupA (37.5%). No association was found between the four genes of the plasticity region and the virulence genes. The presence of the intact locus integrated by jhp0940-jhp0945-jhp0947-jhp0949 was very common among the isolates from children. The genes jhp0940, jhp0947, and jhp0949 were present in more than 50% of the H. pylori isolates, and the joint presence of jhp0940-jhp0945-jhp0947-jhp0949 was very frequent. The frequency of these genes in isolates from children could contribute to the virulence of H. pylori and the evolution of the infection. © 2015 John Wiley & Sons Ltd.

Induction of TLR-2 and TLR-5 expression by Helicobacter pylori switches cagPAI-dependent signalling leading to the secretion of IL-8 and TNF-α.

Directory of Open Access Journals (Sweden)

Suneesh Kumar Pachathundikandi

2011-05-01

Full Text Available Helicobacter pylori is the causative agent for developing gastritis, gastric ulcer, and even gastric cancer. Virulent strains carry the cag pathogenicity island (cagPAI encoding a type-IV secretion system (T4SS for injecting the CagA protein. However, mechanisms of sensing this pathogen through Toll-like receptors (TLRs and downstream signalling pathways in the development of different pathologies are widely unclear. Here, we explored the involvement of TLR-2 and TLR-5 in THP-1 cells and HEK293 cell lines (stably transfected with TLR-2 or TLR-5 during infection with wild-type H. pylori and isogenic cagPAI mutants. H. pylori triggered enhanced TLR-2 and TLR-5 expression in THP-1, HEK293-TLR2 and HEK293-TLR5 cells, but not in the HEK293 control. In addition, IL-8 and TNF-α cytokine secretion in THP-1 cells was induced in a cagPAI-dependent manner. Furthermore, we show that HEK293 cells are not competent for the uptake of T4SS-delivered CagA, and are therefore ideally suited for studying TLR signalling in the absence of T4SS functions. HEK293 control cells, which do not induce TLR-2 and TLR-5 expression during infection, only secreted cytokines in small amounts, in agreement with T4SS functions being absent. In contrast, HEK293-TLR2 and HEK293-TLR5 cells were highly competent for inducing the secretion of IL-8 and TNF-α cytokines in a cagPAI-independent manner, suggesting that the expression of TLR-2 or TLR-5 has profoundly changed the capability to trigger pro-inflammatory signalling upon infection. Using phospho-specific antibodies and luciferase reporter assays, we further demonstrate that H. pylori induces IRAK-1 and IκB phosphorylation in a TLR-dependent manner, and this was required for activation of transcription factor NF-κB. Finally, NF-κB activation in HEK293-TLR2 and HEK293-TLR5 cells was confirmed by expressing p65-GFP which was translocated from the cytoplasm into the nucleus. These data indicate that H. pylori-induced expression

Original Article

African Journals Online (AJOL)

Conclusion: H. pylori infection with cagA positive strains was similarly common in dyspeptic diabetic patients and controls. It was associated with poorer glycemic control and higher rates of microalbuminuria in diabetic subjects. Key words: cagA positive strains; Diabetes mellitus;. Helicobatcer pylori; Microalbuminuria.

The role of environmental tobacco exposure and Helicobacter pylori infection in the risk of chronic tonsillitis in children

Directory of Open Access Journals (Sweden)

Chen Li’e

Full Text Available ABSTRACT CONTEXT AND OBJECTIVE: Helicobacter pylori (H. pylori is a chronic infectious pathogen with high prevalence. This study investigated the interaction between environmental tobacco exposure and H. pylori infection on the incidence of chronic tonsillitis in Chinese children. DESIGN AND SETTING: Cross-sectional study performed in an outpatient clinic in China. METHODS: Pediatric patients with chronic tonsillitis were enrolled. H. pylori infection was determined according to the presence of H. pylori CagA IgG antibodies. Serum cotinine levels and environmental tobacco smoke (ETS exposure were determined for all participants. RESULTS: There was no significant difference in H. pylori infection between the children with chronic tonsillitis and children free of disease, but there was a significant difference in ETS between the two groups (P = 0.011. We next studied the association between ETS and chronic tonsillitis based on H. pylori infection status. In the patients with H. pylori infection, there was a significant difference in ETS distribution between the chronic tonsillitis and control groups (P = 0.022. Taking the participants without ETS as the reference, multivariate logistic regression analysis showed that those with high ETS had higher susceptibility to chronic tonsillitis (adjusted OR = 2.33; 95% CI: 1.67-3.25; adjusted P < 0.001. However, among those without H. pylori infection, ETS did not predispose towards chronic tonsillitis. CONCLUSION: Our findings suggest that tobacco exposure should be a putative mediator risk factor to chronic tonsillitis among children with H. pylori infection.

VacA, CagA, IceA and OipA Genotype Status of Helicobacter pylori ...

African Journals Online (AJOL)

particularly can ease loneliness, reduce allergies, anxiety, depression, stress, and a variety of human diseases, and .... isolated from food stuff was also statistically analyzed. ..... Helicobacter pylori strains from the high-altitude desert of Ladakh ...

Induction of CD69 expression by cagPAI-positive Helicobacter pylori infection

Institute of Scientific and Technical Information of China (English)

Naoki Mori; Chie Ishikawa; Masachika Senba

2011-01-01

AIM: To investigate and elucidate the molecular mech-anism that regulates inducible expression of CD69 by Helicobacter pylori (H. pylori ) infection.METHODS: The expression levels of CD69 in a T-cell line, Jurkat, primary human peripheral blood mononu-clear cells (PBMCs), and CD4+T cells, were assessed by immunohistochemistry, reverse transcription polymerase chain reaction, and flow cytometry. Activation of CD69 promoter was detected by reporter gene. Nuclear factor (NF)-κB activation in Jurkat cells infected with H. pylori was evaluated by electrophoretic mobility shift assay. The role of NF-κB signaling in H. pylori -induced CD69 expression was analyzed using inhibitors of NF-κB and dominant-negative mutants. The isogenic mutants with disrupted cag pathogenicity island ( cagPAI) and virD4 were used to elucidate the role of cagPAI-encoding type Ⅳ secretion system and CagA in CD69 expression.RESULTS: CD69 staining was detected in mucosal lymphocytes and macrophages in specimens of pa-tients with H. pylori -positive gastritis. Although cagPAI-positive H. pylori and an isogenic mutant of virD4 induced CD69 expression, an isogenic mutant of cag-PAI failed to induce this in Jurkat cells. H. pylori also induced CD69 expression in PBMCs and CD4+T cells. The activation of the CD69 promoter by H. pylori was mediated through NF-κB. Transfection of dominant-negative mutants of IκBs, IκB kinases, and NF-κB-inducing kinase inhibited H. pylori -induced CD69 activation. Inhibitors of NF-κB suppressed H. pylori -induced CD69 mRNA expression.CONCLUSION: The results suggest that H. pylori in-duces CD69 expression through the activation of NF-κB. cagPAI might be relevant in the induction of CD69 expression in T cells. CD69 in T cells may play a role in H. pylori -induced gastritis.

Human gastric mucins differently regulate Helicobacter pylori proliferation, gene expression and interactions with host cells.

Directory of Open Access Journals (Sweden)

Emma C Skoog

Full Text Available Helicobacter pylori colonizes the mucus niche of the gastric mucosa and is a risk factor for gastritis, ulcers and cancer. The main components of the mucus layer are heavily glycosylated mucins, to which H. pylori can adhere. Mucin glycosylation differs between individuals and changes during disease. Here we have examined the H. pylori response to purified mucins from a range of tumor and normal human gastric tissue samples. Our results demonstrate that mucins from different individuals differ in how they modulate both proliferation and gene expression of H. pylori. The mucin effect on proliferation varied significantly between samples, and ranged from stimulatory to inhibitory, depending on the type of mucins and the ability of the mucins to bind to H. pylori. Tumor-derived mucins and mucins from the surface mucosa had potential to stimulate proliferation, while gland-derived mucins tended to inhibit proliferation and mucins from healthy uninfected individuals showed little effect. Artificial glycoconjugates containing H. pylori ligands also modulated H. pylori proliferation, albeit to a lesser degree than human mucins. Expression of genes important for the pathogenicity of H. pylori (babA, sabA, cagA, flaA and ureA appeared co-regulated in response to mucins. The addition of mucins to co-cultures of H. pylori and gastric epithelial cells protected the viability of the cells and modulated the cytokine production in a manner that differed between individuals, was partially dependent of adhesion of H. pylori to the gastric cells, but also revealed that other mucin factors in addition to adhesion are important for H. pylori-induced host signaling. The combined data reveal host-specific effects on proliferation, gene expression and virulence of H. pylori due to the gastric mucin environment, demonstrating a dynamic interplay between the bacterium and its host.

Neither genotype nor the gastric colonization site of Helicobacter pylori are predictive factors for the development of erosive esophagitis in patients with peptic ulcer disease, 1 year after eradication O genótipo e o local no estômago de isolamento do Helicobacter pylori em pacientes com úlcera péptica não são fatores preditivos para o desenvolvimento de esofagite erosiva 1 ano após a erradicação da bactéria

Directory of Open Access Journals (Sweden)

Carlos Alexandre Gonçalves Batista

2009-09-01

Full Text Available CONTEXT: Whether Helicobacter pylori infection is a protective or predisposing factor for the development of gastroesophageal reflux disease remains controversial. The most virulent strains, such as those expressing the cytotoxin-associated gene A (CagA, and the site of gastric colonization have been correlated with the prevention or development of esophagitis. AIM: To determine the incidence of erosive esophagitis following eradication of H. pylori in patients with peptic ulcer disease and to evaluate the association of erosive esophagitis with virulent strains of H. pylori and the site of gastric colonization. METHODS: Triple therapy with lansoprazole, amoxicillin and clarithromycin was administered to 159 patients with peptic ulcer disease. Endoscopy, histopathology, urease and carbon-14 urea breath tests were performed prior to treatment, at 3 months and 1 year following treatment. Genotyping of H. pylori strains using polymerase chain reaction was performed separately on samples from the corpus and antrum. RESULTS: One year after treatment, 148 successfully treated patients were reevaluated. Twenty-eight patients (19% had erosive esophagitis, classified as Los Angeles grade A in 24 and B in 4. The samples taken from the corpus were CagA-positive in 18 patients (64%, while the samples taken from the antrum were CagA-positive in 21 patients (75%. CONCLUSIONS: The incidence of erosive esophagitis in peptic ulcer patients who had their H. pylori eradicated was 19%. No correlation was found between the gastric site colonized by H. pylori or strains expressing CagA and the prevention or development of erosive esophagitis in patients with peptic ulcer disease, 1 year after infection eradication.CONTEXTO: É controverso se a infecção pelo Helicobacter pylori é um fator de proteção ou de predisposição para o desenvolvimento da doença de refluxo gastroesofágico. Cepas mais virulentas tais como as que expressam a citotoxina CagA e o local no

Frecuencia de genes de virulencia en infecciones mixtas con cepas de Helicobacter pylori de una población mexicana

Directory of Open Access Journals (Sweden)

R. González-Vázquez

2016-01-01

Conclusiones: La prueba de Fisher no mostró una asociación significativa entre el resultado clínico y el genotipo en la población estudiada. Los genotipos circulantes en la población mexicana fueron cagA+, vacAs1, vacAm1. La PCR multiplex puede usarse para genotipificar rápidamente las cepas de H. pylori. cagE es un buen marcador para identificar cepas cag-PAI+.

Helicobacter pylori Disrupts Host Cell Membranes, Initiating a Repair Response and Cell Proliferation

Directory of Open Access Journals (Sweden)

Hsueh-Fen Juan

2012-08-01

Full Text Available Helicobacter pylori (H. pylori, the human stomach pathogen, lives on the inner surface of the stomach and causes chronic gastritis, peptic ulcer, and gastric cancer. Plasma membrane repair response is a matter of life and death for human cells against physical and biological damage. We here test the hypothesis that H. pylori also causes plasma membrane disruption injury, and that not only a membrane repair response but also a cell proliferation response are thereby activated. Vacuolating cytotoxin A (VacA and cytotoxin-associated gene A (CagA have been considered to be major H. pylori virulence factors. Gastric cancer cells were infected with H. pylori wild type (vacA+/cagA+, single mutant (ΔvacA or ΔcagA or double mutant (ΔvacA/ΔcagA strains and plasma membrane disruption events and consequent activation of membrane repair components monitored. H. pylori disrupts the host cell plasma membrane, allowing localized dye and extracellular Ca²⁺ influx. Ca²⁺-triggered members of the annexin family, A1 and A4, translocate, in response to injury, to the plasma membrane, and cell surface expression of an exocytotic maker of repair, LAMP-2, increases. Additional forms of plasma membrane disruption, unrelated to H. pylori exposure, also promote host cell proliferation. We propose that H. pylori activation of a plasma membrane repair is pro-proliferative. This study might therefore provide new insight into potential mechanisms of H. pylori-induced gastric carcinogenesis.

Relationship between ureB Sequence Diversity, Urease Activity and Genotypic Variations of Different Helicobacter pylori Strains in Patients with Gastric Disorders.

Science.gov (United States)

Ghalehnoei, Hossein; Ahmadzadeh, Alireza; Farzi, Nastaran; Alebouyeh, Masoud; Aghdaei, Hamid Asadzadeh; Azimzadeh, Pendram; Molaei, Mahsa; Zali, Mohammad Reza

2016-01-01

Association of the severity of Helicobacter pylori induced diseases with virulence entity of the colonized strains was proven in some studies. Urease has been demonstrated as a potent virulence factor for H. pylori. The main aim of this study was investigation of the relationships of ureB sequence diversity, urease activity and virulence genotypes of different H. pylori strains with histopathological changes of gastric tissue in infected patients suffering from different gastric disorders. Analysis of the virulence genotypes in the isolated strains indicated significant associations between the presence of severe active gastritis and cagA+ (P = 0.039) or cagA/iceA1 genotypes (P = 0.026), and intestinal metaplasia and vacA m1 (P = 0.008) or vacA s1/m2 (P = 0.001) genotypes. Our results showed a 2.4-fold increased risk of peptic ulcer (95% CI: 0.483-11.93), compared with gastritis, in the infected patients who had dupA positive strains; however this association was not statistically significant. The results of urease activity showed a significant mean difference between the isolated strains from patients with PUD and NUD (P = 0.034). This activity was relatively higher among patients with intestinal metaplasia. Also a significant association was found between the lack of cagA and increased urease activity among the isolated strains (P = 0.036). While the greatest sequence variation of ureB was detected in a strain from a patient with intestinal metaplasia, the sole determined amino acid change in UreB sequence (Ala201Thr, 30%), showed no influence on urease activity. In conclusion, the supposed role of H. pylori urease to form peptic ulcer and advancing of intestinal metaplasia was postulated in this study. Higher urease activity in the colonizing H. pylori strains that present specific virulence factors was indicated as a risk factor for promotion of histopathological changes of gastric tissue that advance gastric malignancy.

The Prevalence of Helicobacter pylori in Estonian Bariatric Surgery Patients

Directory of Open Access Journals (Sweden)

Natalja Šebunova

2018-01-01

Full Text Available Helicobacter pylori (Hp is one of the most important human pathogens that can cause duodenal and gastric ulcers, gastritis and stomach cancer. Hp infection is considered to be a cause of limiting access to bariatric surgery. The aim of this study was to determine the prevalence of Hp in patients with obesity going into bariatric surgery and to reveal the relationship between Hp and clinical data. The study group was formed of 68 preoperative bariatric surgery patients (body mass index (BMI 44.7 ± 4.8. Gastric biopsies (antrum and corpus were used for histological and molecular (caqA and glmM genes examinations. The PCR method revealed Hp infection in 64.7% of obese patients that is higher in comparison with histological analysis (55.9%. The prevalence of cagA and glmM genes in antrum mucosa was 45.6% and 47.0% while in the corpus it was 41.2% and 38.3%, respectively. The coincidence of both cagA and glmM virulence genes in the antrum and corpus mucosa was 33.8% and 22.1%, respectively. Either of the genes was found in 58.8% of antrum and 57.3% of corpus mucosa. Presence of caqA and glmM genes was in association with active and atrophic chronic gastritis. In conclusion, our study demonstrated that two thirds of morbidly obese patients undergoing bariatric surgery are infected with Hp and have a high prevalence of cagA and glmM virulence genes that points out the necessity for diagnostics and treatment of this infection before surgery.

The histone-like protein HU has a role in gene expression during the acid adaptation response in Helicobacter pylori.

Science.gov (United States)

Álvarez, Alhejandra; Toledo, Héctor

2017-08-01

Gastritis, ulcers, and gastric malignancy have been linked to human gastric epithelial colonization by Helicobacter pylori. Characterization of the mechanisms by which H. pylori adapts to the human stomach environment is of crucial importance to understand H. pylori pathogenesis. In an effort to extend our knowledge of these mechanisms, we used proteomic analysis and qRT-PCR to characterize the role of the histone-like protein HU in the response of H. pylori to low pH. Proteomic analysis revealed that genes involved in chemotaxis, oxidative stress, or metabolism are under control of the HU protein. Also, expression of the virulence factors Ggt and NapA is affected by the null mutation of hup gene both at neutral and acid pH, as evidenced by qRT-PCR analysis. Those results showed that H. pylori gene expression is altered by shift to low pH, thus confirming that acid exposure leads to profound changes in genomic expression, and suggest that the HU protein is a regulator that may help the bacterium adapt to the acid stress. In accordance with previous reports, we found that the HU protein participates in gene expression regulation when the microorganism is exposed to acid stress. Such transcriptional regulation underlies protein accumulation in the H. pylori cell. © 2017 John Wiley & Sons Ltd.

Novel protein interactions with an actin homolog (MreB) of Helicobacter pylori determined by bacterial two-hybrid system.

Science.gov (United States)

Zepeda Gurrola, Reyna Cristina; Fu, Yajuan; Rodríguez Luna, Isabel Cristina; Benítez Cardoza, Claudia Guadalupe; López López, María de Jesús; López Vidal, Yolanda; Gutíerrez, Germán Rubén Aguilar; Rodríguez Pérez, Mario A; Guo, Xianwu

2017-08-01

The bacterium Helicobacter pylori infects more than 50% of the world population and causes several gastroduodenal diseases, including gastric cancer. Nevertheless, we still need to explore some protein interactions that may be involved in pathogenesis. MreB, an actin homolog, showed some special characteristics in previous studies, indicating that it could have different functions. Protein functions could be realized via protein-protein interactions. In the present study, the MreB protein from H. pylori 26695 fused with two tags 10×His and GST in tandem was overexpressed and purified from Escherchia coli. The purified recombinant protein was used to perform a pull-down assay with H. pylori 26695 cell lysate. The pulled-down proteins were identified by mass spectrometry (MALDI-TOF), in which the known important proteins related to morphogenesis were absent but several proteins related to pathogenesis process were observed. The bacterial two-hybrid system was further used to evaluate the protein interactions and showed that new interactions of MreB respectively with VacA, UreB, HydB, HylB and AddA were confirmed but the interaction MreB-MreC was not validated. These results indicated that the protein MreB in H. pylori has a distinct interactome, does not participate in cell morphogenesis via MreB-MreC but could be related to pathogenesis. Copyright © 2017 Elsevier GmbH. All rights reserved.

Helicobacter pylori in Vegetables and Salads: Genotyping and Antimicrobial Resistance Properties

Directory of Open Access Journals (Sweden)

Emad Yahaghi

2014-01-01

Full Text Available From a clinical and epidemiological perspective, it is important to know which genotypes and antibiotic resistance patterns are present in H. pylori strains isolated from salads and vegetables. Therefore, the present investigation was carried out to find this purpose. Three hundred eighty washed and unwashed vegetable samples and fifty commercial and traditional salad samples were collected from Isfahan, Iran. Samples were cultured and those found positive for H. pylori were analyzed using PCR. Antimicrobial susceptibility testing was performed using disk diffusion method. Seven out of 50 (14% salad and 52 out of 380 (13.68% vegetable samples harbored H. pylori. In addition, leek, lettuce, and cabbage were the most commonly contaminated samples (30%. The most prevalent virulence genes were oipA (86.44% and cagA (57.625. VacA s1a (37.28% and iceA1 (47.45% were the most prevalent genotypes. Forty different genotypic combinations were recognized. S1a/cagA+/iceA1/oipA+ (33.89%, s1a/cagA+/iceA2/oipA (30.50%, and m1a/cagA+/iceA1/oipA+ (28.81% were the most prevalent combined genotypes. Bacterial strains had the highest levels of resistance against metronidazole (77.96%, amoxicillin (67.79%, and ampicillin (61.01%. High similarity in the genotyping pattern of H. pylori among vegetable and salad samples and human specimens suggests that vegetable and salads may be the sources of the bacteria.

Piperine treatment suppresses Helicobacter pylori toxin entry in to gastric epithelium and minimizes β-catenin mediated oncogenesis and IL-8 secretion in vitro

Science.gov (United States)

Tharmalingam, Nagendran; Park, Min; Lee, Min Ho; Woo, Hyun Jun; Kim, Hyun Woo; Yang, Ji Yeong; Rhee, Ki-Jong; Kim, Jong-Bae

2016-01-01

Helicobacter pylori related gastric cancer initiation has been studied widely. The objective of our present study was to evaluate the effect of a single compound piperine on H. pylori infection and its anti-inflammatory and anti-cancer effects in vitro. Cytotoxicity was tested by Ez-cytox cell viability assay kit. Effects of piperine on H. pylori toxin gene expression and IL-8 expression in mammalian cells during infection were assessed by RT-PCR. Effects of piperine on toxin entry into host cells, E-cadherin cleavage by H. pylori, and the changes in H. pylori mediated β-catenin expression and IL-8 secretion were determined by immunoblotting. Piperine treatment restrained the entry of CagA and VacA into AGS cells. Piperine administration in H. pylori infection reduced E-cadherin cleavage in stomach epithelium. In addition, H. pylori induced β-catenin up-regulation was reduced. Piperine administration impaired IL-8 secretion in H. pylori-infected gastric epithelial cells. As we reported previously piperine restrained H. pylori motility. The possible reason behind the H. pylori inhibition mechanism of piperine could be the dwindled motility, which weakened H. pylori adhesion to gastric epithelial cells. The reduced adhesion decreased the toxin entry thereby secreting less amount of IL-8. In addition, piperine treatment suppressed H. pylori protease led to reduction of E-cadherin cleavage and β-catenin expression resulting in diminished β-catenin translocation into the nucleus thus decreasing the risk of oncogenesis. To our knowledge, this is the preliminary report of piperine mediated H. pylori infection control on gastric epithelial cells in-vitro. PMID:27158376

Isolation and Identification of Outer Membrane Proteins of Helicobacter Pylori of Iranian Patient by SDS-PAGE

Directory of Open Access Journals (Sweden)

M. Doosty

1998-04-01

Full Text Available The function of Helicobacter pylori (H.pylori is confirmed as one of the factors which motivates gastric and duodenal ulcer and gastritis. Various methods are used to diagnose the infection. Serological tests are the easiest and most harmless for the patients. Probably, H.pylori strains in Iran are different from the strains in other countries. Hence, it seems neccessary to design a specific serological test to recognize and identify different strains of bacterial antigenic proteins of Iranian patients."nSince the most manifest and specific to these bacterial antigens are the "Outer Membrane Protein" (OMP, therefore, the first necessary step is to separate and purify H.pylori OMP and then to identify antigenic proteins."nIn this study, we received bacteria colony that belonged to 15 patients with gastric or duodenal ulcer, which had been growed in blood agar or brucella broth. After processing such as washing, freezing and defreezing, sonicating, centrifugation with high speed (10,000 g and treatment with sarcosyl, the sarcosyl insoluble fraction was extracted. Sodium Dodecyl Sulfate - Poly Acrylamide Gel Electrophoresis (SDS-PAGE was preformed. From all 15 OMP specimens, we isolated protein bands."nThe first two bands with higher MW, were major bands and the two lighter bands were the minor bands. Approximate MW of these 4 proteins are equal to 67000, 61000, 30000 and 17000 dalton

Early-life family structure and microbially induced cancer risk.

Directory of Open Access Journals (Sweden)

Martin J Blaser

2007-01-01

Full Text Available Cancer may follow exposure to an environmental agent after many decades. The bacterium Helicobacter pylori, known to be acquired early in life, increases risk for gastric adenocarcinoma, but other factors are also important. In this study, we considered whether early-life family structure affects the risk of later developing gastric cancer among H. pylori+ men.We examined a long-term cohort of Japanese-American men followed for 28 y, and performed a nested case-control study among those carrying H. pylori or the subset carrying the most virulent cagA+ H. pylori strains to address whether family structure predicted cancer development. We found that among the men who were H. pylori+ and/or cagA+ (it is possible to be cagA+ and H. pylori- if the H. pylori test is falsely negative, belonging to a large sibship or higher birth order was associated with a significantly increased risk of developing gastric adenocarcinoma late in life. For those with cagA+ strains, the risk of developing gastric cancer was more than twice as high (odds ratio 2.2; 95% confidence interval 1.2-4.0 among those in a sibship of seven or more individuals than in a sibship of between one and three persons.These results provide evidence that early-life social environment plays a significant role in risk of microbially induced malignancies expressing five to eight decades later, and these findings lead to new models to explain these interactions.

Early-life family structure and microbially induced cancer risk.

Science.gov (United States)

Blaser, Martin J; Nomura, Abraham; Lee, James; Stemmerman, Grant N; Perez-Perez, Guillermo I

2007-01-01

Cancer may follow exposure to an environmental agent after many decades. The bacterium Helicobacter pylori, known to be acquired early in life, increases risk for gastric adenocarcinoma, but other factors are also important. In this study, we considered whether early-life family structure affects the risk of later developing gastric cancer among H. pylori+ men. We examined a long-term cohort of Japanese-American men followed for 28 y, and performed a nested case-control study among those carrying H. pylori or the subset carrying the most virulent cagA+ H. pylori strains to address whether family structure predicted cancer development. We found that among the men who were H. pylori+ and/or cagA+ (it is possible to be cagA+ and H. pylori- if the H. pylori test is falsely negative), belonging to a large sibship or higher birth order was associated with a significantly increased risk of developing gastric adenocarcinoma late in life. For those with cagA+ strains, the risk of developing gastric cancer was more than twice as high (odds ratio 2.2; 95% confidence interval 1.2-4.0) among those in a sibship of seven or more individuals than in a sibship of between one and three persons. These results provide evidence that early-life social environment plays a significant role in risk of microbially induced malignancies expressing five to eight decades later, and these findings lead to new models to explain these interactions.

DNA-binding activity of TNF-α inducing protein from Helicobacter pylori

International Nuclear Information System (INIS)

Kuzuhara, T.; Suganuma, M.; Oka, K.; Fujiki, H.

2007-01-01

Tumor necrosis factor-α (TNF-α) inducing protein (Tipα) is a carcinogenic factor secreted from Helicobacter pylori (H. pylori), mediated through both enhanced expression of TNF-α and chemokine genes and activation of nuclear factor-κB. Since Tipα enters gastric cancer cells, the Tipα binding molecules in the cells should be investigated. The direct DNA-binding activity of Tipα was observed by pull down assay using single- and double-stranded genomic DNA cellulose. The surface plasmon resonance assay, indicating an association between Tipα and DNA, revealed that the affinity of Tipα for (dGdC)10 is 2400 times stronger than that of del-Tipα, an inactive Tipα. This suggests a strong correlation between DNA-binding activity and carcinogenic activity of Tipα. And the DNA-binding activity of Tipα was first demonstrated with a molecule secreted from H. pylori

Helicobacter pylori Type IV Secretion System and Its Adhesin Subunit, CagL, Mediate Potent Inflammatory Responses in Primary Human Endothelial Cells

Directory of Open Access Journals (Sweden)

Mona Tafreshi

2018-02-01

Full Text Available The Gram-negative bacterium, Helicobacter pylori, causes chronic gastritis, peptic ulcers, and gastric cancer in humans. Although the gastric epithelium is the primary site of H. pylori colonization, H. pylori can gain access to deeper tissues. Concurring with this notion, H. pylori has been found in the vicinity of endothelial cells in gastric submucosa. Endothelial cells play crucial roles in innate immune response, wound healing and tumorigenesis. This study examines the molecular mechanisms by which H. pylori interacts with and triggers inflammatory responses in endothelial cells. We observed that H. pylori infection of primary human endothelial cells stimulated secretion of the key inflammatory cytokines, interleukin-6 (IL-6 and interleukin-8 (IL-8. In particular, IL-8, a potent chemokine and angiogenic factor, was secreted by H. pylori-infected endothelial cells to levels ~10- to 20-fold higher than that typically observed in H. pylori-infected gastric epithelial cells. These inflammatory responses were triggered by the H. pylori type IV secretion system (T4SS and the T4SS-associated adhesin CagL, but not the translocation substrate CagA. Moreover, in contrast to integrin α5β1 playing an essential role in IL-8 induction by H. pylori upon infection of gastric epithelial cells, both integrin α5β1 and integrin αvβ3 were dispensable for IL-8 induction in H. pylori-infected endothelial cells. However, epidermal growth factor receptor (EGFR is crucial for mediating the potent H. pylori-induced IL-8 response in endothelial cells. This study reveals a novel mechanism by which the H. pylori T4SS and its adhesin subunit, CagL, may contribute to H. pylori pathogenesis by stimulating the endothelial innate immune responses, while highlighting EGFR as a potential therapeutic target for controlling H. pylori-induced inflammation.

The co-evolved Helicobacter pylori and gastric cancer: trinity of bacterial virulence, host susceptibility and lifestyle

Directory of Open Access Journals (Sweden)

Devi S Manjulata

2007-01-01

Full Text Available Abstract Helicobacter pylori is an important yet unproven etiological agent of gastric cancer. H. pylori infection is more prevalent in developing Asian countries like India and it is usually acquired at an early age. It has been two decades since Marshall and Warren (1984 first described curved bacilli in the stomach of ulcer and gastritis patients. This discovery has won them the Nobel Prize recently, but the debate whether H. pylori is a pathogen or a commensal organism is still hot. Associations with disease-specific factors remain illusive years after the genome sequences were made available. Cytotoxin-associated antigen A (CagA and the so-called plasticity region cluster genes are implicated in pathogenesis of the carcinoma of stomach. Another virulence factor VacA whose role is still debatable, has recently been projected in pathology of gastric cancer. Studies of the evolution through genetic variation in H. pylori populations have provided a window into the history of human population migrations and a possible co-evolution of this pathogen with its human host. Possible symbiotic relationships were seriously debated since the discovery of this pathogen. The debate has been further intensified as some studies proposed H. pylori infection to be beneficial in some humans. In this commentary, we attempt to briefly discuss about H. pylori as a human pathogen, and some of the important issues linked to its pathophysiology in different hosts. 'We dance around in a ring and suppose, the secret sits in the middle and knows' – Robert Frost

IgG immune responses to different proteins of Helicobacter Pylori as defined by immunoblot assay

Directory of Open Access Journals (Sweden)

Raeiszadeh M

2000-09-01

Full Text Available Helicobacter pylori (H.pylori is an etiologic factor for chronic gastritis and peptic ulcers. Serological testing of H.pylori infection is common in Iran, as other parts of the world. There are geographical variations in the humoral immune response to various H. pylori strains in different parts of the worl. We studied the immunogenic proteins of H.pylori by means of an Immunoblot assay with antigens of H.pylori strains isolated in Iran. Sera of 64 patients suffering from dyspepsia were analyzed to determine antibodlies which were good marker of infection and the antibody patterns associated with peptic ulcer.54 out of 64 dyspeptic patients were infected by H. pylori based on positive culture or positive results of both rapid urease test and direct examination. 14 out of fity-four had peptic ulcers and the rest were catagoriied as patients with non-ulcer dyspepsia. Some of them had multiple erosions in the gut or deodenum. Tweny –two major bands were identified by immunoblot. Of these, IgG antibodies against 10 protients, and they produced immunoreative bands at 14, 16, 22, 26, 32 , 32, 44, 87, 92, 120 Kda. Antibody patterns were not identical in the patients. The presence of at least one band at 14, 16, 22, 26, 32, 35Kda was the best marker of infection(sensitivity, 90% and specificity, 80% Major serological cross reactions were found at moderate molecular weight bands (50, 52, 54, 60, 66 KDa. The presence of at least one band at 14, 16, 22, 26, 32, 35Kda was the best marker of infection (sensitivity, 90% and specificity, 80%. Major serological crossreactions were found at moderate molerate molecular weight bands (50, 52, 54, 60, 66 KDa. The presence of antibodies to 120 Kda protein (Cag A and 87 Kda Protein (Vac A were not associated with the presence of peptic ulcers. These were in contradiction to results obtained across Europe and U.S but in agreement with Asian studies. However the presence of at least one band at either 32 or 35 Kda was

Extremely low Helicobacter pylori prevalence in North Sulawesi, Indonesia and identification of a Maori-tribe type strain: a cross sectional study.

Science.gov (United States)

Miftahussurur, Muhammad; Tuda, Josef; Suzuki, Rumiko; Kido, Yasutoshi; Kawamoto, Fumihiko; Matsuda, Miyuki; Tantular, Indah S; Pusarawati, Suhintam; Nasronudin; Harijanto, Paul N; Yamaoka, Yoshio

2014-01-01

Sulawesi in Indonesia has a unique geographical profile with assumed separation from Sundaland. Studies of Helicobacter pylori in this region are rare due to the region's rural location and lack of endoscopy equipment. Indirect methods are, therefore, the most appropriate for measuring H. pylori infection in these areas; with the disposable gastric brush test, we can obtain gastric juice as well as small gastric tissue samples for H. pylori culture. We investigated the prevalence of H. pylori infection and evaluated human migration patterns in the remote areas of North Sulawesi. We recruited a total of 251 consecutive adult volunteers and 131 elementary school children. H. pylori infection was determined by urine antibody test. A gastric brush test was used to culture H. pylori. We used next-generation and polymerase chain reaction based sequencing to determine virulence factors and multi-locus sequence typing (MLST). The overall H. pylori prevalence was only 14.3% for adults and 3.8% for children, and 13.6% and 16.7% in Minahasanese and Mongondownese participants, respectively. We isolated a single H. pylori strain, termed -Manado-1. Manado-1 was East Asian type cagA (ABD type), vacA s1c-m1b, iceA1 positive/iceA2 negative, jhp0562-positive/β-(1,3) galT-negative, oipA "on", and dupA-negative. Phylogenetic analyses showed the strain to be hspMaori type, a major type observed in native Taiwanese and Maori tribes. Our data support that very low H. pylori infection prevalence in Indonesia. Identification of hspMaori type H. pylori in North Sulawesi may support the hypothesis that North Sulawesi people migrated from north.

A new crystal lattice structure of Helicobacter pylori neutrophil-activating protein (HP-NAP)

International Nuclear Information System (INIS)

Tsuruta, Osamu; Yokoyama, Hideshi; Fujii, Satoshi

2012-01-01

A new crystal lattice structure of H. pylori neutrophil-activating protein has been determined. Iron loading causes a series of conformational changes at the ferroxidase centre. A new crystal lattice structure of Helicobacter pylori neutrophil-activating protein (HP-NAP) has been determined in two forms: the native state (Apo) at 2.20 Å resolution and an iron-loaded form (Fe-load) at 2.50 Å resolution. The highly solvated packing of the dodecameric shell is suitable for crystallographic study of the metal ion-uptake pathway. Like other bacterioferritins, HP-NAP forms a spherical dodecamer with 23 symmetry including two kinds of channels. Iron loading causes a series of conformational changes of amino-acid residues (Trp26, Asp52 and Glu56) at the ferroxidase centre

Comparative Genomics of H. pylori and Non-Pylori Helicobacter Species to Identify New Regions Associated with Its Pathogenicity and Adaptability

Directory of Open Access Journals (Sweden)

De-Min Cao

2016-01-01

Full Text Available The genus Helicobacter is a group of Gram-negative, helical-shaped pathogens consisting of at least 36 bacterial species. Helicobacter pylori (H. pylori, infecting more than 50% of the human population, is considered as the major cause of gastritis, peptic ulcer, and gastric cancer. However, the genetic underpinnings of H. pylori that are responsible for its large scale epidemic and gastrointestinal environment adaption within human beings remain unclear. Core-pan genome analysis was performed among 75 representative H. pylori and 24 non-pylori Helicobacter genomes. There were 1173 conserved protein families of H. pylori and 673 of all 99 Helicobacter genus strains. We found 79 genome unique regions, a total of 202,359bp, shared by at least 80% of the H. pylori but lacked in non-pylori Helicobacter species. The operons, genes, and sRNAs within the H. pylori unique regions were considered as potential ones associated with its pathogenicity and adaptability, and the relativity among them has been partially confirmed by functional annotation analysis. However, functions of at least 54 genes and 10 sRNAs were still unclear. Our analysis of protein-protein interaction showed that 30 genes within them may have the cooperation relationship.

Comparative genomic analysis of Helicobacter pylori from Malaysia identifies three distinct lineages suggestive of differential evolution.

Science.gov (United States)

Kumar, Narender; Mariappan, Vanitha; Baddam, Ramani; Lankapalli, Aditya K; Shaik, Sabiha; Goh, Khean-Lee; Loke, Mun Fai; Perkins, Tim; Benghezal, Mohammed; Hasnain, Seyed E; Vadivelu, Jamuna; Marshall, Barry J; Ahmed, Niyaz

2015-01-01

The discordant prevalence of Helicobacter pylori and its related diseases, for a long time, fostered certain enigmatic situations observed in the countries of the southern world. Variation in H. pylori infection rates and disease outcomes among different populations in multi-ethnic Malaysia provides a unique opportunity to understand dynamics of host-pathogen interaction and genome evolution. In this study, we extensively analyzed and compared genomes of 27 Malaysian H. pylori isolates and identified three major phylogeographic lineages: hspEastAsia, hpEurope and hpSouthIndia. The analysis of the virulence genes within the core genome, however, revealed a comparable pathogenic potential of the strains. In addition, we identified four genes limited to strains of East-Asian lineage. Our analyses identified a few strain-specific genes encoding restriction modification systems and outlined 311 core genes possibly under differential evolutionary constraints, among the strains representing different ethnic groups. The cagA and vacA genes also showed variations in accordance with the host genetic background of the strains. Moreover, restriction modification genes were found to be significantly enriched in East-Asian strains. An understanding of these variations in the genome content would provide significant insights into various adaptive and host modulation strategies harnessed by H. pylori to effectively persist in a host-specific manner. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

adolescents with gastroduodenal disease

Directory of Open Access Journals (Sweden)

Monika Maria Biernat

2014-08-01

Full Text Available Introduction: Infection with Helicobacter pylori is a major cause of chronic gastritis and peptic ulcer disease in children and its consequences in adulthood can lead to serious complications, including in particular the development of gastric cancer. Our aim was to analyze the relationship between the occurrence of selected genes such as cagA, vacA, iceA, and babA2 determining pathogenicity of H. pylori strains and clinical outcome in children.Material and methods: The study was performed on H. pylori strains isolated from biopsies taken from 130 children and adolescents with non-ulcer dyspepsia (NUD, gastric and duodenal ulcers (PUD and gastroesophageal reflux disease (GERD. Genes such as cagA, vacA (allelic variants: s1/ s2, m1/m2, iceA (allelic variants: iceA1, iceA2 and babA2 were determined by polymerase chain reaction (PCR.Results: The cagA gene was detected in 79/130 (60.8% H. pylori isolates. The presence of the cagA gene was significantly associated with duodenal ulcer (p<0.05. The vacAs1/m1 genotype as more frequent in children with ulcers than in other groups, whereas the vacAs2/m2 genotype was more frequent in patients with gastritis and GERD. The iceA1, iceA2 and babA2 genes were present in 59/130 (45.4%, 27/130 (21% and 30/130 (23.1% of the strains, respectively. The vacAs1/cagA+ genotype was most frequently observed in strains isolated from children with PUD. The predominant genotype in children with NUD and GERD was vacAs2/cagA-/iceA1+/babA2-.Conclusion: The study showed a high incidence of strains with increased virulence, possessing cagA, vacAs1 and iceA1 genes in symptomatic children with H. pylori infection.

The effect of Helicobacter pylori eradication on macrophage migration inhibitory factor, C-reactive protein and fetuin-a levels

Directory of Open Access Journals (Sweden)

Levent Kebapcilar

2010-06-01

Full Text Available OBJECTIVES: To determine the effect of Helicobacter pylori (H. pylori eradication on blood levels of high-sensitivity C-reactive protein (hs-CRP, macrophage migration inhibitory factor and fetuin-A in patients with dyspepsia who are concurrently infected with H. pylori. METHODS: H.pylori infection was diagnosed based on the 14C urea breath test (UBT and histology. Lansoprazole 30 mg twice daily, amoxicillin 1 g twice daily, and clarithromycin 500 mg twice daily were given to all infected patients for 14 days; 14C UBT was then re-measured. In 30 subjects, migration inhibitory factor, fetuin-A and hs-CRP levels were examined before and after the eradication of H. pylori infection and compared to levels in 30 healthy subjects who tested negative for H. pylori infection. RESULTS: Age and sex distribution were comparable between patients and controls. Migration inhibitory factor and hs-CRP levels were higher, and fetuin-A levels were lower, in H. pylori-infected patients (p0.05. CONCLUSION: These findings suggest that H. pylori eradication reduces the levels of pro-inflammatory cytokines such as migration inhibitory factor and hs-CRP and also results in a significant increase in anti-inflammatory markers such as fetuin-A.

Did transmission of Helicobacter pylori from humans cause a disease outbreak in a colony of Stripe-faced Dunnarts (Sminthopsis macroura?

Directory of Open Access Journals (Sweden)

Every Alison L

2011-02-01

Full Text Available Abstract Since the discovery that Helicobacter pylori causes a range of pathologies in the stomachs of infected humans, it has become apparent that Helicobacters are found in a diverse range of animal species where they are frequently associated with disease. In 2003 and 2004, there were two outbreaks of increased mortality associated with gastric bleeding and weight-loss in a captive colony of the Australian marsupial, the Stripe-faced Dunnart (Sminthopsis macroura. The presence of gastric pathology led to an investigation of potential Helicobacter pathogenesis in these animals. Histological examination revealed the presence of gastritis, and PCR analysis confirmed the presence of Helicobacter infection in the stomachs of these marsupials. Surprisingly, sequencing of 16S rRNA from these bacteria identified the species as H. pylori and PCR confirmed the strain to be positive for the important pathogenesis factor, cagA. We therefore describe, for the first time, an apparent reverse zoonotic infection of Stripe-faced Dunnarts with H. pylori. Already prone to pathological effects of stress (as experienced during breeding season, concomitant H. pylori infection appears to be a possible essential but not sufficient co-factor in prototypic gastric bleeding and weight loss in these marsupials. The Stripe-faced Dunnart could represent a new model for investigating Helicobacter-driven gastric pathology. Infections from their human handlers, specifically of H. pylori, may be a potential risk to captive colonies of marsupials.

Foveolar cells phagocytose apoptotic neutrophils in chronic active Helicobacter pylori gastritis.

Science.gov (United States)

Caruso, R A; Fedele, F; Di Bella, C; Mazzon, E; Rigoli, L

2012-11-01

The recognition and removal of apoptotic inflammatory cells by tissue macrophages and non-professional phagocytes, in a process called efferocytosis, is required for resolution of inflammation and is actively anti-inflammatory. We have previously demonstrated phagocytosis of apoptotic neutrophils by tumor cells in human gastric carcinoma, but to date, there have been no studies investigating this process in chronic active Helicobacter pylori gastritis. Biopsy specimens from 28 subjects with or without H. pylori infection and active inflammation were examined and graded according to the updated Sydney system. Light microscopy, electron microscopy, and Terminal Deoxynucleotidyltransferase-Mediated UTP End Labeling staining were used to identify apoptosis. H. pylori infection was detected by histology and by molecular assay in 16 out of 28 cases. DNA from paraffin-embedded gastric biopsies was amplified using primers specific for cagA, for the cag "empty site" as well as for the s and m alleles of vacA. The more virulent cagA-positive strains were found in five out of nine patients with chronic active gastritis. The vacA s1/m1 and s2/m1 genotypes were more common in nine patients with chronic active gastritis, while the vacA s2/m2 genotype was more frequent in seven patients with chronic inactive gastritis. Apoptotic neutrophils were also detected within the cytoplasmic vacuoles of the foveolar cells of nine cases with chronic active gastritis. Transmission electron micrographs revealed further apoptotic neutrophils within spacious phagosomes of foveolar cells in a similar manner to those described in late-phase efferocytosis both in vivo and in vitro. These new observations expand the morphological spectrum of gastritis in patients infected with more virulent H. pylori strains, compatible with an anti-inflammatory role for the gastric epithelial cells in their removal of apoptotic neutrophils during active chronic gastritis.

Helicobacter pylori virulence genes and microevolution in host and the clinical outcome: review article

Directory of Open Access Journals (Sweden)

Seyedeh Zahra Bakhti

2014-12-01

Full Text Available Helicobacter pylori (H. pylori is the causative agent in development of gastroduode-nal diseases, such as chronic atrophic gastritis, peptic ulcers, mucosa associated lym-phoid tissue (MALT lymphoma, and gastric cancer. H. pylori has been associated with inflammation in cardia, showing the fact that infection with this bacterium could also be a risk factor for gastric cardia cancer. Gastric cancer is the fourth most common cancer worldwide. This is the second leading cause of cancer-related deaths, and ap-proximately 700,000 people succumb each year to gastric adenocarcinoma. It has been estimated that 69% of the Iranian population currently harbor H. pylori infection. The prevalence of duodenal ulcer and gastric cancer is high in Iranian populations. However, this has been largely influenced by geographic and/or ethnic origin. Epidemi-ology studies have shown that host, environmental, and bacterial factors determine the outcome of H. pylori infection. The bacterium contains allelic diversity and high genet-ic variability into core- and virulence-genes and that this diversity is geographically and ethnically structured. The genetic diversity within H. pylori is greater than within most other bacteria, and its diversity is more than 50-fold higher than that of human DNA. The maintenance of high diversification makes this bacterium to cope with particular challenges in individual hosts. It has been reported that the recombination contributed to the creation of new genes and gene family. Furthermore, the microevolution in cagA and vacA genes is a common event, leading to a change in the virulence phenotype. These factors contribute to the bacterial survival in acidic conditions in stomach and protect it from host immune system, causing tissue damage and clinical disease. In this review article, we discussed the correlation between H. pylori virulence factors and clin-ical outcomes, microevolution of H. pylori virulence genes in a single host

Macrophage migration inhibitory factor stimulated by Helicobacter pylori increases proliferation of gastric epithelial cells

Science.gov (United States)

Xia, Harry Hua-Xiang; Lam, Shiu Kum; Chan, Annie O.O.; Lin, Marie Chia Mi; Kung, Hsiang Fu; Ogura, Keiji; Berg, Douglas E.; Wong, Benjamin C. Y.

2005-01-01

AIM: Helicobacter pylori (H pylori) is associated with increased gastric inflammatory and epithelial expression of macrophage migration inhibitory factor (MIF) and gastric epithelial cell proliferation. This study aimed at determining whether H pylori directly stimulates release of MIF in monocytes, whether the cag pathogenicity island (PAI) is involved for this function, and whether MIF stimulated by H pylori increases gastric epithelial cell proliferation in vitro. METHODS: A cytotoxic wild-type H pylori strain (TN2)and its three isogenic mutants (TN2△cag, TN2△cagA and TN2△cagE) were co-cultured with cells of a human monocyte cell line, THP-1, for 24 h at different organism/cell ratios. MIF in the supernatants was measured by an ELISA. Cells of a human gastric cancer cell line, MKN45, were then co-cultured with the supernatants, with and without monoclonal anti-MIF antibody for 24 h. The cells were further incubated for 12 h after addition of 3H-thymidine, and the levels of incorporation of 3H-thymidine were measured with a liquid scintillation counter. RESULTS: The wild-type strain and the isogenic mutants, TN2△cagA and TN2△cagE, increased MIF release at organism/cell ratios of 200/1 and 400/1, but not at the ratios of 50/1 and 100/1. However, the mutant TN2△cag did not increase the release of MIF at any of the four ratios. 3H-thymidine readings for MKN-45 cells were significantly increased with supernatants derived from the wild-type strain and the mutants TN2△cagA and TN2△cagE, but not from the mutant TN2△cag. Moreover, in the presence of monoclonal anti-MIF antibody, the stimulatory effects of the wild-type strain on cell proliferation disappeared. CONCLUSION: H pylori stimulates MIF release in monocytes, likely through its cag PAI, but not related to cagA or cagE. H pylori-stimulated monocyte culture supernatant increases gastric cell proliferation, which is blocked by anti-MIF antibody, suggesting that MIF plays an important role in H

Gastric epithelial expression of IL-12 cytokine family in Helicobacter pylori infection in human: is it head or tail of the coin?

Directory of Open Access Journals (Sweden)

Fadi Al-Sammak

Full Text Available Recently, there has been a growing interest in an expanding group of cytokines known as "IL-12 family". The so far gained knowledge about these cytokines, as crucial playmakers in mucosal immunity, has not yet been sufficiently investigated in the context of Helicobacter pylori infection. All genes encoding the monomeric components of these cytokines and their corresponding receptors were examined in gastric epithelial cell lines (AGS and MKN-28 after being infected with 4 H. pylori strains: BCM-300, P1 wild-type, and P1-derived isogenic mutants lacking cytotoxin-associated gene A (cagA or virulence gene virB7 (multiplicity of infection=50. Both infected and uninfected samples were analyzed after 24h and 48h using real-time quantitative polymerase chain reaction (RT-qPCR. Gene expression analysis demonstrated a strong upregulation of IL23A (encodes p19 by infection, whereas IL23R, Epstein-Barr virus-induced gene 3 (EBI3, IL6ST, IL12A, and IL27RA were found to be expressed, but not regulated, or to a lesser extent. Transcripts of IL12RB2, IL12B, IL12RB1, and IL27A were not detected. Interestingly, P1 resulted in stronger alterations of expression than CagA mutant and BCM-300, particularly for IL23A (59.7-fold versus 32.4- and 6.7-fold, respectively in AGS after 48h, P<.05, whereas no changes were seen with VirB7 mutant. In a proof-of-principle experiment, we demonstrated epithelial-derived expression of IL-12, p19, and Ebi3 in gastric mucosa of gastritis patients using immunohistochemistry (IHC. Unlike IL-12 and Ebi3, increased immunostaining of p19 was observed in H. pylori gastritis. Herein, we highlight the potential role of gastric epithelial cells in mucosal immunity, not only because they are predominant cell type in mucosa and initial site of host-bacterial interaction, but also as a major contributor to molecules that are thought to be primarily expressed by immune cells so far. Of these molecules, p19 was the most relevant one to H

Phylogeographic origin of Helicobacter pylori determines host-adaptive responses upon coculture with gastric epithelial cells.

Science.gov (United States)

Sheh, Alexander; Chaturvedi, Rupesh; Merrell, D Scott; Correa, Pelayo; Wilson, Keith T; Fox, James G

2013-07-01

While Helicobacter pylori infects over 50% of the world's population, the mechanisms involved in the development of gastric disease are not fully understood. Bacterial, host, and environmental factors play a role in disease outcome. To investigate the role of bacterial factors in H. pylori pathogenesis, global gene expression of six H. pylori isolates was analyzed during coculture with gastric epithelial cells. Clustering analysis of six Colombian clinical isolates from a region with low gastric cancer risk and a region with high gastric cancer risk segregated strains based on their phylogeographic origin. One hundred forty-six genes had increased expression in European strains, while 350 genes had increased expression in African strains. Differential expression was observed in genes associated with motility, pathogenicity, and other adaptations to the host environment. European strains had greater expression of the virulence factors cagA, vacA, and babB and were associated with increased gastric histologic lesions in patients. In AGS cells, European strains promoted significantly higher interleukin-8 (IL-8) expression than did African strains. African strains significantly induced apoptosis, whereas only one European strain significantly induced apoptosis. Our data suggest that gene expression profiles of clinical isolates can discriminate strains by phylogeographic origin and that these profiles are associated with changes in expression of the proinflammatory and protumorigenic cytokine IL-8 and levels of apoptosis in host epithelial cells. These findings support the hypothesis that bacterial factors determined by the phylogeographic origin of H. pylori strains may promote increased gastric disease.

The association of dupA and Helicobacter pylori-related gastroduodenal diseases.

Science.gov (United States)

Hussein, N R

2010-07-01

Helicobacter pylori is associated with the development of ulceration and gastric cancer. Recently, a novel virulence factor, duodenal ulcer promoting gene A (dupA), has been identified and found to associate with disease in some populations but not others. We investigated the relationship of dupA genotypes and H. pylori-related clinical outcomes by meta-analysis using previous reports of 2,358 patients from around the world. dupA-positive genotypes was found in 48% and was associated with duodenal ulcer (p = 0.001, odds ratio [OR] = 1.4, confidence interval [CI] = 1.1-1.7). The prevalence of dupA-positivity and its association with disease differed among the various regions around the world. In South America, the highest prevalence was recorded (Colombia and Brazil) and a significant relationship was found between dupA-negative strains and both gastric ulcer (GU) and gastric cancer (GC) (for GU, p = 0.001, OR = 0.2, CI = 0.1-0.4 and for GC, p = 0.001, OR = 0.3, CI = 0.2-0.6). In China, a significant correlation between dupA-positive strains and GU (p = 0.001, OR = 5.5, CI = 2.4-12.4) and GC (p = 0.009, OR = 2, Cl = 1.1-3.1) was found. To conclude, dupA promotes duodenal ulceration in some populations and GU and GC in others. This is typical of other virulence factors, such as cagA. Hence, it was concluded that the H. pylori virulence factor, dupA, is a true virulence factor.

Helicobacter pylori Diversity and Gastric Cancer Risk

Directory of Open Access Journals (Sweden)

Timothy L. Cover

2016-03-01

Full Text Available Gastric cancer is a leading cause of cancer-related death worldwide. Helicobacter pylori infection is the strongest known risk factor for this malignancy. An important goal is to identify H. pylori-infected persons at high risk for gastric cancer, so that these individuals can be targeted for therapeutic intervention. H. pylori exhibits a high level of intraspecies genetic diversity, and over the past two decades, many studies have endeavored to identify strain-specific features of H. pylori that are linked to development of gastric cancer. One of the most prominent differences among H. pylori strains is the presence or absence of a 40-kb chromosomal region known as the cag pathogenicity island (PAI. Current evidence suggests that the risk of gastric cancer is very low among persons harboring H. pylori strains that lack the cag PAI. Among persons harboring strains that contain the cag PAI, the risk of gastric cancer is shaped by a complex interplay among multiple strain-specific bacterial factors as well as host factors. This review discusses the strain-specific properties of H. pylori that correlate with increased gastric cancer risk, focusing in particular on secreted proteins and surface-exposed proteins, and describes evidence from cell culture and animal models linking these factors to gastric cancer pathogenesis. Strain-specific features of H. pylori that may account for geographic variation in gastric cancer incidence are also discussed.

Electron Microscopic, Genetic and Protein Expression Analyses of Helicobacter acinonychis Strains from a Bengal Tiger

Science.gov (United States)

Tegtmeyer, Nicole; Rivas Traverso, Francisco; Rohde, Manfred; Oyarzabal, Omar A.; Lehn, Norbert; Schneider-Brachert, Wulf; Ferrero, Richard L.; Fox, James G.; Berg, Douglas E.; Backert, Steffen

2013-01-01

Colonization by Helicobacter species is commonly noted in many mammals. These infections often remain unrecognized, but can cause severe health complications or more subtle host immune perturbations. The aim of this study was to isolate and characterize putative novel Helicobacter spp. from Bengal tigers in Thailand. Morphological investigation (Gram-staining and electron microscopy) and genetic studies (16SrRNA, 23SrRNA, flagellin, urease and prophage gene analyses, RAPD DNA fingerprinting and restriction fragment polymorphisms) as well as Western blotting were used to characterize the isolated Helicobacters. Electron microscopy revealed spiral-shaped bacteria, which varied in length (2.5–6 µm) and contained up to four monopolar sheathed flagella. The 16SrRNA, 23SrRNA, sequencing and protein expression analyses identified novel H. acinonychis isolates closely related to H. pylori. These Asian isolates are genetically very similar to H. acinonychis strains of other big cats (cheetahs, lions, lion-tiger hybrid and other tigers) from North America and Europe, which is remarkable in the context of the great genetic diversity among worldwide H. pylori strains. We also found by immunoblotting that the Bengal tiger isolates express UreaseA/B, flagellin, BabA adhesin, neutrophil-activating protein NapA, HtrA protease, γ-glutamyl-transpeptidase GGT, Slt lytic transglycosylase and two DNA transfer relaxase orthologs that were known from H. pylori, but not the cag pathogenicity island, nor CagA, VacA, SabA, DupA or OipA proteins. These results give fresh insights into H. acinonychis genetics and the expression of potential pathogenicity-associated factors and their possible pathophysiological relevance in related gastric infections. PMID:23940723

Electron microscopic, genetic and protein expression analyses of Helicobacter acinonychis strains from a Bengal tiger.

Directory of Open Access Journals (Sweden)

Nicole Tegtmeyer

Full Text Available Colonization by Helicobacter species is commonly noted in many mammals. These infections often remain unrecognized, but can cause severe health complications or more subtle host immune perturbations. The aim of this study was to isolate and characterize putative novel Helicobacter spp. from Bengal tigers in Thailand. Morphological investigation (Gram-staining and electron microscopy and genetic studies (16SrRNA, 23SrRNA, flagellin, urease and prophage gene analyses, RAPD DNA fingerprinting and restriction fragment polymorphisms as well as Western blotting were used to characterize the isolated Helicobacters. Electron microscopy revealed spiral-shaped bacteria, which varied in length (2.5-6 µm and contained up to four monopolar sheathed flagella. The 16SrRNA, 23SrRNA, sequencing and protein expression analyses identified novel H. acinonychis isolates closely related to H. pylori. These Asian isolates are genetically very similar to H. acinonychis strains of other big cats (cheetahs, lions, lion-tiger hybrid and other tigers from North America and Europe, which is remarkable in the context of the great genetic diversity among worldwide H. pylori strains. We also found by immunoblotting that the Bengal tiger isolates express UreaseA/B, flagellin, BabA adhesin, neutrophil-activating protein NapA, HtrA protease, γ-glutamyl-transpeptidase GGT, Slt lytic transglycosylase and two DNA transfer relaxase orthologs that were known from H. pylori, but not the cag pathogenicity island, nor CagA, VacA, SabA, DupA or OipA proteins. These results give fresh insights into H. acinonychis genetics and the expression of potential pathogenicity-associated factors and their possible pathophysiological relevance in related gastric infections.

Electron microscopic, genetic and protein expression analyses of Helicobacter acinonychis strains from a Bengal tiger.

Science.gov (United States)

Tegtmeyer, Nicole; Rivas Traverso, Francisco; Rohde, Manfred; Oyarzabal, Omar A; Lehn, Norbert; Schneider-Brachert, Wulf; Ferrero, Richard L; Fox, James G; Berg, Douglas E; Backert, Steffen

2013-01-01

Colonization by Helicobacter species is commonly noted in many mammals. These infections often remain unrecognized, but can cause severe health complications or more subtle host immune perturbations. The aim of this study was to isolate and characterize putative novel Helicobacter spp. from Bengal tigers in Thailand. Morphological investigation (Gram-staining and electron microscopy) and genetic studies (16SrRNA, 23SrRNA, flagellin, urease and prophage gene analyses, RAPD DNA fingerprinting and restriction fragment polymorphisms) as well as Western blotting were used to characterize the isolated Helicobacters. Electron microscopy revealed spiral-shaped bacteria, which varied in length (2.5-6 µm) and contained up to four monopolar sheathed flagella. The 16SrRNA, 23SrRNA, sequencing and protein expression analyses identified novel H. acinonychis isolates closely related to H. pylori. These Asian isolates are genetically very similar to H. acinonychis strains of other big cats (cheetahs, lions, lion-tiger hybrid and other tigers) from North America and Europe, which is remarkable in the context of the great genetic diversity among worldwide H. pylori strains. We also found by immunoblotting that the Bengal tiger isolates express UreaseA/B, flagellin, BabA adhesin, neutrophil-activating protein NapA, HtrA protease, γ-glutamyl-transpeptidase GGT, Slt lytic transglycosylase and two DNA transfer relaxase orthologs that were known from H. pylori, but not the cag pathogenicity island, nor CagA, VacA, SabA, DupA or OipA proteins. These results give fresh insights into H. acinonychis genetics and the expression of potential pathogenicity-associated factors and their possible pathophysiological relevance in related gastric infections.

B-Cell and T-Cell Immune Responses to Experimental Helicobacter pylori Infection in Humans

Science.gov (United States)

Nurgalieva, Zhannat Z.; Conner, Margaret E.; Opekun, Antone R.; Zheng, Carl Q.; Elliott, Susan N.; Ernst, Peter B.; Osato, Michael; Estes, Mary K.; Graham, David Y.

2005-01-01

The acute antibody and T-cell immune response to Helicobacter pylori infection in humans has not been studied systematically. Serum from H. pylori-naive volunteers challenged with H. pylori and cured after 4 or 12 weeks was tested by enzyme-linked immunosorbent assays for anti-H. pylori-specific immunoglobulin M (IgM) and IgA established using bacterial lysates from homologous (the infecting strain) and heterologous H. pylori. Proteins recognized by IgM antibody were identified by mass spectrometry of immunoreactive bands separated by two-dimensional gel electrophoresis. Mucosal T-cell subsets (CD4, CD8, CD3, and CD30 cells) were assessed by immunohistochemistry. All 18 infected volunteers developed H. pylori-specific IgM responses to both homologous or heterologous H. pylori antigens. H. pylori antigens reacted with IgM antibody at 4 weeks postinfection. IgM Western blotting showed immunoreactivity of postinfection serum samples to multiple H. pylori proteins with molecular weights ranging between 9,000 (9K) to 150K with homologous strains but only a 70K band using heterologous antigens. Two-dimensional electrophoresis demonstrated that production of H. pylori-specific IgM antibodies was elicited by H. pylori flagellins A and B, urease B, ABC transporter binding protein, heat shock protein 70 (DnaK), and alkyl hydroperoxide reductase. Mucosal CD3, CD4, and CD8 T-cell numbers increased following infection. IgM antibody responses were detected to a range of homologous H. pylori antigens 2 to 4 weeks postchallenge. The majority of H. pylori proteins were those involved in motility and colonization and may represent targets for vaccine development. PMID:15845507

Helicobacter pylori bab characterization in clinical isolates from Bhutan, Myanmar, Nepal and Bangladesh.

Directory of Open Access Journals (Sweden)

Shamshul Ansari

Full Text Available Helicobacter pylori BabA is an important outer membrane protein that involves in the attachment to the gastric mucosa and enhances the virulence property of the bacterium. This study was aimed to characterize the bab genotypes, to evaluate its association with cagA, vacA and clinical diseases as well as degree of gastric inflammation.H. pylori isolates from four countries were subjected for the characterization of bab. The locus specific forward and bab specific reverse primers were used to get the specific products by PCR, which could distinguish the three locus (A, B and C. The histological activities were evaluated according to the Updated Sydney system.In patients from high risk countries (Bhutan and Myanmar relatively higher frequencies of strains with babA-positivity (91.8% and 90.7%, respectively, babA at locus A (98% and 91.2%, respectively and with single babA (96.8% and 91.2%, respectively were found. Strains with two loci occupied were the most prevalent in Bhutan (84.6%, Myanmar (74.7%, Nepal (58.3% and Bangladesh (56.9%. The genotype babA at locus A/babB at locus B/bab-negative at locus C (babA/babB/- was the most common genotype isolated from Bhutan (82.7%, Myanmar (58.7%, Nepal (32% and Bangladesh (31.4% among all genotypes assessed. This genotype was also associated with the peptic ulcer disease (P = 0.013 when compared to gastritis. babA-positive characteristics and the genotype babA/babB/- exhibited the enhanced histological activities.The higher prevalence of virulence associated babA-positive characteristics and enhanced histological activities in Bhutan than in Myanmar, Nepal and Bangladesh might partly explain why the peoples in Bhutan are at higher risk for developing severe gastric complications.

Helicobacter pylori bab characterization in clinical isolates from Bhutan, Myanmar, Nepal and Bangladesh.

Science.gov (United States)

Ansari, Shamshul; Kabamba, Evariste Tshibangu; Shrestha, Pradeep Krishna; Aftab, Hafeza; Myint, Thein; Tshering, Lotay; Sharma, Rabi Prakash; Ni, Nwe; Aye, Than Than; Subsomwong, Phawinee; Uchida, Tomohisa; Ratanachu-Ek, Thawee; Vilaichone, Ratha-Korn; Mahachai, Varocha; Matsumoto, Takashi; Akada, Junko; Yamaoka, Yoshio

2017-01-01

Helicobacter pylori BabA is an important outer membrane protein that involves in the attachment to the gastric mucosa and enhances the virulence property of the bacterium. This study was aimed to characterize the bab genotypes, to evaluate its association with cagA, vacA and clinical diseases as well as degree of gastric inflammation. H. pylori isolates from four countries were subjected for the characterization of bab. The locus specific forward and bab specific reverse primers were used to get the specific products by PCR, which could distinguish the three locus (A, B and C). The histological activities were evaluated according to the Updated Sydney system. In patients from high risk countries (Bhutan and Myanmar) relatively higher frequencies of strains with babA-positivity (91.8% and 90.7%, respectively), babA at locus A (98% and 91.2%, respectively) and with single babA (96.8% and 91.2%, respectively) were found. Strains with two loci occupied were the most prevalent in Bhutan (84.6%), Myanmar (74.7%), Nepal (58.3%) and Bangladesh (56.9%). The genotype babA at locus A/babB at locus B/bab-negative at locus C (babA/babB/-) was the most common genotype isolated from Bhutan (82.7%), Myanmar (58.7%), Nepal (32%) and Bangladesh (31.4%) among all genotypes assessed. This genotype was also associated with the peptic ulcer disease (P = 0.013) when compared to gastritis. babA-positive characteristics and the genotype babA/babB/- exhibited the enhanced histological activities. The higher prevalence of virulence associated babA-positive characteristics and enhanced histological activities in Bhutan than in Myanmar, Nepal and Bangladesh might partly explain why the peoples in Bhutan are at higher risk for developing severe gastric complications.

Prediction of extracellular proteases of the human pathogen Helicobacter pylori reveals proteolytic activity of the Hp1018/19 protein HtrA.

Directory of Open Access Journals (Sweden)

Martin Löwer

Full Text Available Exported proteases of Helicobacter pylori (H. pylori are potentially involved in pathogen-associated disorders leading to gastric inflammation and neoplasia. By comprehensive sequence screening of the H. pylori proteome for predicted secreted proteases, we retrieved several candidate genes. We detected caseinolytic activities of several such proteases, which are released independently from the H. pylori type IV secretion system encoded by the cag pathogenicity island (cagPAI. Among these, we found the predicted serine protease HtrA (Hp1019, which was previously identified in the bacterial secretome of H. pylori. Importantly, we further found that the H. pylori genes hp1018 and hp1019 represent a single gene likely coding for an exported protein. Here, we directly verified proteolytic activity of HtrA in vitro and identified the HtrA protease in zymograms by mass spectrometry. Overexpressed and purified HtrA exhibited pronounced proteolytic activity, which is inactivated after mutation of Ser205 to alanine in the predicted active center of HtrA. These data demonstrate that H. pylori secretes HtrA as an active protease, which might represent a novel candidate target for therapeutic intervention strategies.

Relationship of IL-1 and TNF-α polymorphisms with Helicobacter pylori in gastric diseases in a Brazilian population

International Nuclear Information System (INIS)

Santos, J.C.; Ladeira, M.S.P.; Pedrazzoli, J. Jr.; Ribeiro, M.L.

2012-01-01

It is well known that the risk of development of gastric cancer (GC) in Helicobacter pylori-infected patients depends on several factors. Thus, the aim of this study was to investigate the effect of proinflammatory cytokine gene polymorphisms for IL-1β, IL-1RN and TNF-α on the development of GC in a Brazilian population. A total of 202 biopsies obtained from Brazilian patients with chronic gastritis and GC were included in the study. Infection with H. pylori cagA + was determined by the polymerase chain reaction (PCR) as previously described. IL-1β, IL-1RN and TNF-α polymorphism genotyping was performed by restriction fragment length polymorphism PCR. Associations between gene polymorphisms, clinical diseases and virulence markers were evaluated using either the X 2 test or the Fisher exact test. Our results demonstrated that the IL-1β -511 C/C and IL-1β -511 C/T alleles were associated with chronic gastritis in H. pylori-positive patients (P = 0.04 and P = 0.05, respectively) and the IL-1β -511 C/C genotype was associated with GC (P = 0.03). The frequency of IL-1RN alleles from patients with chronic gastritis and GC indicated that there was no difference between the genotypes of the groups studied. Similar results were found for TNF-α -308 gene polymorphisms. Our results indicate that the IL-1β -511 C/C and C/T gene polymorphisms are associated with chronic gastritis and GC development in H. pylori-infected individuals

Relationship of IL-1 and TNF-α polymorphisms with Helicobacter pylori in gastric diseases in a Brazilian population

Directory of Open Access Journals (Sweden)

J.C. Santos

2012-09-01

Full Text Available It is well known that the risk of development of gastric cancer (GC in Helicobacter pylori-infected patients depends on several factors. Thus, the aim of this study was to investigate the effect of proinflammatory cytokine gene polymorphisms for IL-1β, IL-1RN and TNF-α on the development of GC in a Brazilian population. A total of 202 biopsies obtained from Brazilian patients with chronic gastritis and GC were included in the study. Infection with H. pylori cagA+ was determined by the polymerase chain reaction (PCR as previously described. IL-1β, IL-1RN and TNF-α polymorphism genotyping was performed by restriction fragment length polymorphism PCR. Associations between gene polymorphisms, clinical diseases and virulence markers were evaluated using either the χ² test or the Fisher exact test. Our results demonstrated that the IL-1β -511 C/C and IL-1β -511 C/T alleles were associated with chronic gastritis in H. pylori-positive patients (P = 0.04 and P = 0.05, respectively and the IL-1β -511 C/C genotype was associated with GC (P = 0.03. The frequency of IL-1RN alleles from patients with chronic gastritis and GC indicated that there was no difference between the genotypes of the groups studied. Similar results were found for TNF-α -308 gene polymorphisms. Our results indicate that the IL-1β -511 C/C and C/T gene polymorphisms are associated with chronic gastritis and GC development in H. pylori-infected individuals.

A potential role for Helicobacter pylori heat shock protein 60 in gastric tumorigenesis

Energy Technology Data Exchange (ETDEWEB)

Lin, Chen-Si [Department of Biological Science and Technology, National Chiao-Tung University, Hsin-Chu, Taiwan (China); School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan (China); He, Pei-Juin [Department of Biological Science and Technology, National Chiao-Tung University, Hsin-Chu, Taiwan (China); Tsai, Nu-Man [School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan (China); Li, Chi-Han; Yang, Shang-Chih; Hsu, Wei-Tung [Department of Biological Science and Technology, National Chiao-Tung University, Hsin-Chu, Taiwan (China); Wu, Ming-Shiang [Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Wu, Chang-Jer [Department of Food Science, National Taiwan Ocean University, Keelung, Taiwan (China); Cheng, Tain-Lu [Department of Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Liao, Kuang-Wen, E-mail: kitchhen@yahoo.com.tw [Department of Biological Science and Technology, National Chiao-Tung University, Hsin-Chu, Taiwan (China)

2010-02-05

Helicobacter pylori has been found to promote the malignant process leading to gastric cancer. Heat shock protein 60 of H. pylori (HpHSP60) was previously been identified as a potent immunogene. This study investigates the role of HpHSP60 in gastric cancer carcinogenesis. The effect of HpHSP60 on cell proliferation, anti-death activity, angiogenesis and cell migration were explored. The results showed that HpHSP60 enhanced migration by gastric cancer cells and promoted tube formation by umbilical vein endothelial cells (HUVECs); however, HpHSP60 did not increase cell proliferation nor was this protein able to rescue gastric cancer cells from death. Moreover, the results also indicated HpHSP60 had different effects on AGS gastric cancer cells or THP-1 monocytic cells in terms of their expression of pro-inflammatory cytokines, which are known to be important to cancer development. We propose that HpHSP60 may trigger the initiation of carcinogenesis by inducing pro-inflammatory cytokine release and by promoting angiogenesis and metastasis. Thus, this extracellular pathogen-derived HSP60 is potentially a vigorous virulence factor that can act as a carcinogen during gastric tumorigenesis.

Helicobacter pylori HP1034 (ylxH) is required for motility

NARCIS (Netherlands)

van Amsterdam, Karin; van der Ende, Arie

2004-01-01

Background. Helicobacter pylori motility is essential for the colonization and persistence in the human gastric mucosa. So far, more than 50 genes have been described to play a role in flagellar biosynthesis. H. pylori YlxH (HP1034) is annotated as an ATP-binding protein. However, H. pylori YlxH

Transformation of heat shock protein gene (HspB-C) of helicobacter pylori into sweet potato varieties

International Nuclear Information System (INIS)

Wu Jie; Yan Wenzhao; Zhou Yu; Zhang Xuemei

2010-01-01

Sweet potato which is one of the most important crops in the world has many advantages as a new bioreactor. Helicobacter pylori, as a kind of cancer-causing factor by the World Health Organization, has a strong immunogenicity, and its monoclonal antibody has bactericidal activity, which has the possibility as the vaccine components. In this research, we have constructed the plant expression vector with heat shock protein gene (HspB-C) of Helicobacter pylori. This vector was transformed by agrobactrium tumefaciens EHA105 into four sweet potato varieties. After callus-induction and re-differentiation, we got the transgenic plants from sweet potato variety of Nancy holl. (authors)

Comparative proteome analysis of Helicobacter pylori clinical strains by two-dimensional gel electrophoresis.

Science.gov (United States)

Zhang, Ya-nan; Ding, Shi-gang; Huang, Liu-huan; Zhang, Jing; Shi, Yan-yan; Zhong, Li-jun

2011-10-01

To investigate the pathogenic properties of Helicobacter pylori by comparing the proteome map of H. pylori clinical strains. Two wild-type H. pylori strains, YN8 (isolated from biopsy tissue of a gastric cancer patient) and YN14 (isolated from biopsy tissue of a gastritis and duodenal ulcer patient), were used. Proteomic analysis, using a pH range of 3-10 and 5-8, was performed. The individual proteins were identified by quadrupole time-of-flight (Q-TOF) mass spectrometer and protein database search. Variation in spot patterns directed towards differential protein expression levels was observed between the strains. The gel revealed prominent proteins with several protein "families". The comparison of protein expressions of the two strains reveals a high variability. Differentially present or absent spots were observed. Nine differentially expressed protein spots identified by Q-TOF included adenosine triphosphate (ATP)-binding protein, disulfide oxidoreductase B (DsbB)-like protein, N utilization substance A (NusA), ATP-dependent protease binding subunit/heat shock protein, hydantoin utilization protein A, seryl-tRNA synthetase, molybdenum ABC transporter ModD, and hypothetical proteins. This study suggests that H. pylori strains express/repress protein variation, not only in terms of the virulence proteins, but also in terms of physiological proteins, when they infect a human host. The difference of protein expression levels between H. pylori strains isolated from gastric cancer and gastritis may be the initiator of inflammation, and result in the different clinical presentation. In this preliminary study, we report seven differential proteins between strains, with molecule weights from approximately 10 kDa to approximately 40 kDa. Further studies are needed to investigate those proteins and their function associated with H. pylori colonization and adaptation to host environment stress.

Oral vaccination with attenuated Salmonella choleraesuis C500 ...

African Journals Online (AJOL)

user

Marshall, 1983), and well known as the major gastro- duodenal ... The CagA is encoded in a pathogenicity island known as 'Cag PAI' and is .... HindIII to release the CagA fragment. The purified .... vaccine strain attenuated by chemical methods, which is .... pylori antigens is achieved using a non-toxic mutant of E. coli heat-.

Crosstalk between Helicobacter pylori and gastric epithelial cells is impaired by docosahexaenoic acid.

Directory of Open Access Journals (Sweden)

Marta Correia

Full Text Available H. pylori colonizes half of the world's population leading to gastritis, ulcers and gastric cancer. H. pylori strains resistant to antibiotics are increasing which raises the need for alternative therapeutic approaches. Docosahexaenoic acid (DHA has been shown to decrease H. pylori growth and its associated-inflammation through mechanisms poorly characterized. We aimed to explore DHA action on H. pylori-mediated inflammation and adhesion to gastric epithelial cells (AGS and also to identify bacterial structures affected by DHA. H. pylori growth and metabolism was assessed in liquid cultures. Bacterial adhesion to AGS cells was visualized by transmission electron microscopy and quantified by an Enzyme Linked Immunosorbent Assay. Inflammatory proteins were assessed by immunoblotting in infected AGS cells, previously treated with DHA. Bacterial total and outer membrane protein composition was analyzed by 2-dimensional gel electrophoresis. Concentrations of 100 µM of DHA decreased H. pylori growth, whereas concentrations higher than 250 µM irreversibly inhibited bacteria survival. DHA reduced ATP production and adhesion to AGS cells. AGS cells infected with DHA pre-treated H. pylori showed a 3-fold reduction in Interleukin-8 (IL-8 production and a decrease of COX2 and iNOS. 2D electrophoresis analysis revealed that DHA changed the expression of H. pylori outer membrane proteins associated with stress response and metabolism and modified bacterial lipopolysaccharide phenotype. As conclusions our results show that DHA anti-H. pylori effects are associated with changes of bacteria morphology and metabolism, and with alteration of outer membrane proteins composition, that ultimately reduce the adhesion of bacteria and the burden of H. pylori-related inflammation.

and the severity of peptic ulcer disease

African Journals Online (AJOL)

MJ, Smith PD. Helicobacter pylori urease is a potent stimulus of mononuclear phagocyte activation and inflammatory cytokine production. Gastroenterology. 1996;111(2):419-425. Peek RM, Miller GG, Tham KT, et al. Heightened. 4. inflammatory response and cytokine expression in vivo to cagA+ Helicobacter pylori strains.

A novel system of cytoskeletal elements in the human pathogen Helicobacter pylori.

Directory of Open Access Journals (Sweden)

Barbara Waidner

2009-11-01

Full Text Available Pathogenicity of the human pathogen Helicobacter pylori relies upon its capacity to adapt to a hostile environment and to escape from the host response. Therefore, cell shape, motility, and pH homeostasis of these bacteria are specifically adapted to the gastric mucus. We have found that the helical shape of H. pylori depends on coiled coil rich proteins (Ccrp, which form extended filamentous structures in vitro and in vivo, and are differentially required for the maintenance of cell morphology. We have developed an in vivo localization system for this pathogen. Consistent with a cytoskeleton-like structure, Ccrp proteins localized in a regular punctuate and static pattern within H. pylori cells. Ccrp genes show a high degree of sequence variation, which could be the reason for the morphological diversity between H. pylori strains. In contrast to other bacteria, the actin-like MreB protein is dispensable for viability in H. pylori, and does not affect cell shape, but cell length and chromosome segregation. In addition, mreB mutant cells displayed significantly reduced urease activity, and thus compromise a major pathogenicity factor of H. pylori. Our findings reveal that Ccrp proteins, but not MreB, affect cell morphology, while both cytoskeletal components affect the development of pathogenicity factors and/or cell cycle progression.

Crystallisation and Preliminary Crystallographic Analysis of Helicobacter pylori Periplasmic Binding Protein YckK

Directory of Open Access Journals (Sweden)

Mohammad Mizanur Rahman

2017-10-01

Full Text Available Helicobacter pylori infection can lead to the development of gastric and duodenal ulcers and gastric cancer. In recent years, the efficacy of the standard therapy has been falling, necessitating ongoing efforts to identify new drug targets. Due to their important role in chemotaxis and nutrient uptake, periplasmic binding proteins (PBPs represent potential targets for new antimicrobial agents that have not yet been fully explored and exploited. The H. pylori PBP YckK is homologous to polar amino acid-binding proteins from other bacteria. The yckK gene overlaps the gene tcyB—a gene annotated as a polar amino acid-transporting permease. Purified recombinant YckK behaved as a monomer in solution. Crystals of YckK were grown by the hanging drop vapour diffusion method using PEG 3350 as the precipitating agent. The crystals belong to the primitive triclinic space group P1 with unit cell parameters a = 63.0, b = 63.5, c = 74.6 Å, α = 72.5, β = 68.3, γ = 69.4°. X-ray diffraction data were collected to 1.8 Å resolution using synchrotron radiation. Molecular replacement using this data revealed that the asymmetric unit contains three subunits: two in the open and one in the closed conformation.

Variations in Helicobacter pylori cytotoxin-associated genes and their influence in progression to gastric cancer: implications for prevention.

Directory of Open Access Journals (Sweden)

Cosmeri Rizzato

Full Text Available Helicobacter pylori (HP is a bacterium that colonizes the human stomach and can establish a long-term infection of the gastric mucosa. Persistent Hp infection often induces gastritis and is associated with the development of peptic ulcer disease, atrophic gastritis, and gastric adenocarcinoma. Virulent HP isolates harbor the cag (cytotoxin-associated genes pathogenicity island (cagPAI, a 40 kb stretch of DNA that encodes components of a type IV secretion system (T4SS. This T4SS forms a pilus for the injection of virulence factors into host target cells, such as the CagA oncoprotein. We analyzed the genetic variability in cagA and other selected genes of the HP cagPAI (cagC, cagE, cagL, cagT, cagV and cag Gamma using DNA extracted from frozen gastric biopsies or from clinical isolates. Study subjects were 95 cagA+ patients that were histologically diagnosed with chronic gastritis or gastric cancer in Venezuela and Mexico, areas with high prevalence of Hp infection. Sequencing reactions were carried out by both Sanger and next-generation pyrosequencing (454 Roche methods. We found a total of 381 variants with unambiguous calls observed in at least 10% of the originally tested samples and reference strains. We compared the frequencies of these genetic variants between gastric cancer and chronic gastritis cases. Twenty-six SNPs (11 non-synonymous and 14 synonymous showed statistically significant differences (P<0.05, and two SNPs, in position 1039 and 1041 of cagE, showed a highly significant association with cancer (p-value = 2.07×10⁻⁶, and the variant codon was located in the VirB3 homology domain of Agrobacterium. The results of this study may provide preliminary information to target antibiotic treatment to high-risk individuals, if effects of these variants are confirmed in further investigations.

Comparative genomics of a Helicobacter pylori isolate from a Chinese Yunnan Naxi ethnic aborigine suggests high genetic divergence and phage insertion.

Directory of Open Access Journals (Sweden)

Yuanhai You

Full Text Available Helicobacter pylori is a common pathogen correlated with several severe digestive diseases. It has been reported that isolates associated with different geographic areas, different diseases and different individuals might have variable genomic features. Here, we describe draft genomic sequences of H. pylori strains YN4-84 and YN1-91 isolated from patients with gastritis from the Naxi and Han populations of Yunnan, China, respectively. The draft sequences were compared to 45 other publically available genomes, and a total of 1059 core genes were identified. Genes involved in restriction modification systems, type four secretion system three (TFS3 and type four secretion system four (TFS4, were identified as highly divergent. Both YN4-84 and YN1-91 harbor intact cag pathogenicity island (cagPAI and have EPIYA-A/B/D type at the carboxyl terminal of cagA. The vacA gene type is s1m2i1. Another major finding was a 32.5-kb prophage integrated in the YN4-84 genome. The prophage shares most of its genes (30/33 with Helicobacter pylori prophage KHP30. Moreover, a 1,886 bp transposable sequence (IS605 was found in the prophage. Our results imply that the Naxi ethnic minority isolate YN4-84 and Han isolate YN1-91 belong to the hspEAsia subgroup and have diverse genome structure. The genome has been extensively modified in several regions involved in horizontal DNA transfer. The important roles played by phages in the ecology and microevolution of H. pylori were further emphasized. The current data will provide valuable information regarding the H. pylori genome based on historic human migrations and population structure.

Association between Virulence Factors and TRAF1/4-1BB/Bcl-xL Expression in Gastric Mucosa Infected with Helicobacter pylori

Directory of Open Access Journals (Sweden)

Fen Wang

2015-01-01

Full Text Available Objective. CagA+/vacAs1+/vacAm1+ Helicobacter pylori upregulates the expression of tumor necrosis factor receptor–associated factor 1 (TRAF1, tumor necrosis factor receptor superfamily member 9 (4-1BB, and B-cell lymphoma-extra large (Bcl-xL in human gastric epithelial cells. We investigated the correlation between cagA/vacAs1/vacAm1 and TRAF1/4-1BB/Bcl-xL expression in gastric mucosal tissue of patients with gastric disorders. Methods. We collected gastric mucosa samples from 35 chronic, nonatrophic gastritis (CG patients, 41 atrophic gastritis patients, 44 intestinal metaplasia with atypical hyperplasia (IM patients, and 28 gastric carcinoma (Ca patients. The expression of  TRAF1, 4-1BB, and Bcl-xL was determined using western blotting. The expression of cagA, vacAs1, and vacAm1 in H. pylori was examined with polymerase chain reaction. Results. The expression of TRAF1, 4-1BB, and Bcl-xL was significantly upregulated in IM and Ca patients (P<0.05 compared with CG. There were more cases of cagA+/vacAs1+/vacAm1+ H. pylori infection in samples with elevated TRAF1, 4-1BB, or Bcl-xL expression (P<0.05. Additionally, there were a remarkably large number of samples with upregulated TRAF1/4-1BB/Bcl-xL expression in cases of cagA+/vacAs1+/vacAm1+ H. pylori infection (44 cases, 67.7%; P<0.05. Conclusions. The pathogenesis of IM and Ca may be promoted by cagA+/vacAs1+/vacAm1+ H. pylori, possibly via upregulated TRAF1, 4-1BB, and Bcl-xL in gastric mucosal tissue.

BH3-only protein Bim is associated with the degree of Helicobacter pylori-induced gastritis and is localized to the mitochondria of inflammatory cells in the gastric mucosa.

Science.gov (United States)

Akazawa, Yuko; Matsuda, Katsuya; Isomoto, Hajime; Matsushima, Kayoko; Kido, Yoko; Urabe, Shigetoshi; Yamaghchi, Naoyuki; Ohnita, Ken; Takeshima, Fuminao; Kondo, Hisayoshi; Tsugawa, Hitoshi; Suzuki, Hidekazu; Moss, Joel; Nakao, Kazuhiko; Nakashima, Masahiro

2015-09-01

BH3-only protein, Bim, is a pro-apoptotic protein that mediates mitochondria-dependent cell death. However, the role of Bim in Helicobacter pylori-associated gastritis remains unclear. This study aimed to assess the cellular localization of Bim and its possible role in H. pylori-induced gastritis. The study was conducted on biopsy specimens obtained from 80 patients who underwent upper gastrointestinal endoscopy (H. pylori-negative: n=30, positive: n=50). Association between Bim mRNA expression and severity of gastritis was evaluated and the localization of Bim was examined by immunofluorescence. Bim mRNA expression was positively correlated with the degree of gastritis, as defined by the Sydney system. Immunohistochemical analysis confirmed increased Bim expression in H. pylori-infected gastric mucosa compared with uninfected mucosa in both humans and mice. Bim localized in myeloperoxidase- and CD138-positive cells of H. pylori-infected lamina propria and submucosa of the gastric tract, indicating that this protein is predominantly expressed in neutrophils and plasma cells. In contrast, Bim did not localize in CD20-, CD3-, or CD68-positive cells. Bim was expressed in the mitochondria, where it was partially co-localized with activated Bax and cleaved-PARP. In conclusion, Bim is expressed in neutrophils and plasma cells in H. pylori-associated gastritis, where it may participate in the termination of inflammatory response by causing mitochondria-mediated apoptosis in specific leucocytes. Copyright © 2015 Elsevier GmbH. All rights reserved.

Concurrent overexpression of serum p53 mutation related with Helicobacter pylori infection

Directory of Open Access Journals (Sweden)

Lorenzo-Peñuelas Antonio

2010-06-01

Full Text Available Abstract Background & Aims In the province of Cadiz (Spain, the adjusted mortality rate for gastric cancer in the coastal town of Barbate is 10/100.000 inhabitants, whereas in the inland town of Ubrique, the rate is twice as high. The rate of Helicobacter pylori (H. pylori infection (H. pylori antibodies in the normal population was 54% in Ubrique, but only 32% in Barbate. In the two decades since its original discovery, p53 has found a singularly prominent place in our understanding of human gastric cancer and H. pylori cause accumulation of reactive oxygen species in the mucosa compartment. This study was designed to compare serum levels of p53 in a population characterized by high mortality due to stomach cancer and a high prevalence of H. pylori infection and another population in which mortality from this cause and the prevalence of H. pylori infection are low. Materials and methods 319 subjects from the low mortality population and 308 from the high mortality population were studied, as were 71 patients with stomach cancer. We measured serum immunoglobulin G antibody to H. pylori and serum mutant p53 protein and ceruloplasmin. Results The difference between the two populations in the prevalence of H. pylori infection was significant (p Conclusions There is a significant association between infection with H. pylori, elevated titers of H. pylori antibodies, and positivity for serum mutant p53 protein. Such information can significantly increase our basic knowledge in molecular pathology of gastric cancer and protection against H. pylori infection.

Lack of association between Helicobacter pylori infection with dupA-positive strains and gastroduodenal diseases in Brazilian patients.

Science.gov (United States)

Gomes, Luciana I; Rocha, Gifone A; Rocha, Andreia M C; Soares, Taciana F; Oliveira, Celso A; Bittencourt, Paulo F S; Queiroz, Dulciene M M

2008-04-01

Duodenal ulcer-promoting gene (dupA) was recently described as a new putative Helicobacter pylori virulence marker associated with an increased risk for duodenal ulcer and reduced risk for gastric carcinoma in Japan and Korea. Since differences regarding the association among H. pylori markers and H. pylori-associated diseases have been demonstrated around the world, we evaluated the presence of the gene in 482 strains from Brazilian children (34 with duodenal ulcer and 97 with gastritis) and adults (126 with duodenal ulcer, 144 with gastritis and 81 with gastric carcinoma) by PCR using the described primers and an additional set of primers based on Brazilian strain sequences. The results were confirmed by sequencing. The presence of cagA was investigated by PCR and also included in the analysis. dupA was present in 445 (92.32%) and absent in 29 (6.02%) strains. All samples from children with and without duodenal ulcer were dupA-positive (p=1.0). No association was observed among the strains from adults with gastritis (92.36%), duodenal ulcer (87.30%, p=0.30) and gastric carcinoma (87.65%, p=0.31). Conversely, cagA-positve status remained independently associated with duodenal ulcer (children: odds ratios (OR)=5.58, 95% confidence intervals (CI)=1.67-18.50; adults: OR=3.33, 95% CI=2.14-5.19) and gastric carcinoma (OR=6.58, 95% CI=3.51-12.30) in multivariate analyses. The presence of dupA was significantly higher in strains from children than in those from adults (p=0.01). In conclusion, dupA is highly frequent and not associated with H. pylori-associated diseases in both Brazilian adults and children, which points to regional differences in the distribution of the gene.

[The prevalence of dupA (duodenal ulcer-promoting gene) of Helicobacter pylori in children and adolescents--own observation].

Science.gov (United States)

Parzecka, Monika; Szaflarska-Popławska, Anna; Gasiorowska, Joanna; Gorzkiewicz, Marta; Grzybowski, Tomasz

2013-05-01

The strains of Helicobacter pylori are described by many common features which determine their virulence. The genes which are connected with much higher virulence of some strains are vacA, cagA, oipA, dupA. Duodenal Ulcer Promoting Gene--dupA is the new virulence factor coexisting with a duodenum ulcer. There is a rationale that shows a protective character of dupA with reference to a stomach cancer. The dupA gene probably causes increasingly higher releasing of pro-infectious IL-8 via stomach cells and it influences the production of IL-12 and other cytokines. The aim of the study was to determine the frequency of dupA gene's appearance in the Polish children's group and in the Polish teenagers' group infected with H. pylori. The research was also aimed to determine the coexistence of dupA gene and duodenum ulcer disease or erosion infection of duodenum's mucous membrane. The endoscopic examination of the upper part of digestive duct was performed in 119 qualified patients with dyspeptic symptoms and with suspicion of stomach and duodenum's mucous membrane infection. The segments were taken for histopathological identification of H. pylori and for genetic indicating via PCR method. To confirm the presence of H. pylori in the extract the amplification of DNA fragment sized 860 pz was used. The presence of dupA gene was detected by PCR reaction with using the starters which include the fragment of jhp0917-jhp0918 sequence in the plastic H. pylori's genome area. To confirm the infection the urea breathing test was taken. 88 patients confirm the infection of H. pylori. The presence of dupA gene was found in 20 patients--a group A (22.7%), whereas in 68 patients dupA gene was not found--a group B (77.2%). Pathological changes in duodenum was found in 20 patients infected with H. pylori (22.7%), included 4 patients in the group A (20%) and 16 in the group B (23.5%). There was an infection (swelling, redness, congestion) in duodenum was found in the group A in all cases

Genomes of Helicobacter pylori from native Peruvians suggest admixture of ancestral and modern lineages and reveal a western type cag-pathogenicity island

Directory of Open Access Journals (Sweden)

Rahman Syed

2006-07-01

Full Text Available Abstract Background Helicobacter pylori is presumed to be co-evolved with its human host and is a highly diverse gastric pathogen at genetic levels. Ancient origins of H. pylori in the New World are still debatable. It is not clear how different waves of human migrations in South America contributed to the evolution of strain diversity of H. pylori. The objective of our 'phylogeographic' study was to gain fresh insights into these issues through mapping genetic origins of H. pylori of native Peruvians (of Amerindian ancestry and their genomic comparison with isolates from Spain, and Japan. Results For this purpose, we attempted to dissect genetic identity of strains by fluorescent amplified fragment length polymorphism (FAFLP analysis, multilocus sequence typing (MLST of the 7 housekeeping genes (atpA, efp, ureI, ppa, mutY, trpC, yphC and the sequence analyses of the babB adhesin and oipA genes. The whole cag pathogenicity-island (cagPAI from these strains was analyzed using PCR and the geographic type of cagA phosphorylation motif EPIYA was determined by gene sequencing. We observed that while European genotype (hp-Europe predominates in native Peruvian strains, approximately 20% of these strains represent a sub-population with an Amerindian ancestry (hsp-Amerind. All of these strains however, irrespective of their ancestral affiliation harbored a complete, 'western' type cagPAI and the motifs surrounding it. This indicates a possible acquisition of cagPAI by the hsp-Amerind strains from the European strains, during decades of co-colonization. Conclusion Our observations suggest presence of ancestral H. pylori (hsp-Amerind in Peruvian Amerindians which possibly managed to survive and compete against the Spanish strains that arrived to the New World about 500 years ago. We suggest that this might have happened after native Peruvian H. pylori strains acquired cagPAI sequences, either by new acquisition in cag-negative strains or by recombination

Expression and Antigenic Evaluation of VacA Antigenic Fragment of Helicobacter Pylori

Science.gov (United States)

Hasanzadeh, Leila; Ghaznavi-Rad, Ehsanollah; Soufian, Safieh; Farjadi, Vahideh; Abtahi, Hamid

2013-01-01

Objective(s) : Helicobacter pylori, a human specific gastric pathogen is a causative agent of chronic active gastritis. The vacuolating cytotoxin (VacA) is an effective virulence factor involved in gastric injury. The aim of this study was to construct a recombinant protein containing antigenic region of VacA gene and determine its antigenicity. Materials and Methods: The antigenic region of VacA gene was detected by bioinformatics methods. The polymerase chain reaction method was used to amplify a highly antigenic region of VacA gene from chromosomal DNA of H. pylori. The eluted product was cloned into the prokaryotic expression vector pET32a. The target protein was expressed in the Escherichia coli BL21 (DE3) pLysS. The bacteria including pET32a-VacA plasmids were induced by IPTG. The antigenicity was finally studied by western blotting using sera of 15 H. pylori infected patients after purification. Results: Enzyme digestion analysis, PCR and DNA sequencing results showed that the target gene was inserted correctly into the recombinant vector. The expressed protein was purified successfully via affinity chromatography. Data indicated that antigenic region of VacA protein from Helicobacter pylori was recognized by all 15 patient’s sera. Conclusion : Our data showed that antigenic region of VacA protein can be expressed by in E. co.li. This protein was recognized by sera patients suffering from H. pylori infection. the recombinant protein has similar epitopes and close antigenic properties to the natural form of this antigen. Recombinant antigenic region of VacA protein also seems to be a promising antigen for protective and serologic diagnosis . PMID:23997913

Expression and Antigenic Evaluation of VacA Antigenic Fragment of Helicobacter Pylori

Directory of Open Access Journals (Sweden)

Leila Hasanzadeh

2013-07-01

Full Text Available Objective(s: Helicobacter pylori, a human specific gastric pathogen is a causative agent of chronic active gastritis. The vacuolating cytotoxin (VacA is an effective virulence factor involved in gastric injury. The aim of this study was to construct a recombinant protein containing antigenic region of VacA gene and determine its antigenicity.   Materials and Methods: The antigenic region of VacA gene was detected by bioinformatics methods. The polymerase chain reaction method was used to amplify a highly antigenic region of VacA gene from chromosomal DNA of H. pylori. The eluted product was cloned into the prokaryotic expression vector pET32a. The target protein was expressed in the Escherichia coli BL21 (DE3 pLysS. The bacteria including pET32a-VacA plasmids were induced by IPTG. The antigenicity was finally studied by western blotting using sera of 15 H. pylori infected patients after purification. Results: Enzyme digestion analysis, PCR and DNA sequencing results showed that the target gene was inserted correctly into the recombinant vector. The expressed protein was purified successfully via affinity chromatography. Data indicated that antigenic region of VacA protein from Helicobacter pylori was recognized by all 15 patient’s sera. Conclusion : Our data showed that antigenic region of VacA protein can be expressed by in E. co.li. This protein was recognized by sera patients suffering from H. pylori infection. the recombinant protein has similar epitopes and close antigenic properties to the natural form of this antigen. Recombinant antigenic region of VacA protein also seems to be a promising antigen for protective and serologic diagnosis .

Woodlands House Nursing Home, Trim Road, Navan, Meath.

LENUS (Irish Health Repository)

O'Toole, Paul W

2010-03-10

Abstract Background Helicobacter mustelae causes gastritis, ulcers and gastric cancer in ferrets and other mustelids. H. mustelae remains the only helicobacter other than H. pylori that causes gastric ulceration and cancer in its natural host. To improve understanding of H. mustelae pathogenesis, and the ulcerogenic and carcinogenic potential of helicobacters in general, we sequenced the H. mustelae genome, and identified 425 expressed proteins in the envelope and cytosolic proteome. Results The H. mustelae genome lacks orthologs of major H. pylori virulence factors including CagA, VacA, BabA, SabA and OipA. However, it encodes ten autotransporter surface proteins, seven of which were detected in the expressed proteome, and which, except for the Hsr protein, are of unknown function. There are 26 putative outer membrane proteins in H. mustelae, some of which are most similar to the Hof proteins of H. pylori. Although homologs of putative virulence determinants of H. pylori (NapA, plasminogen adhesin, collagenase) and Campylobacter jejuni (CiaB, Peb4a) are present in the H. mustelae genome, it also includes a distinct complement of virulence-related genes including a haemagglutinin\\/haemolysin protein, and a glycosyl transferase for producing blood group A\\/B on its lipopolysaccharide. The most highly expressed 264 proteins in the cytosolic proteome included many corresponding proteins from H. pylori, but the rank profile in H. mustelae was distinctive. Of 27 genes shown to be essential for H. pylori colonization of the gerbil, all but three had orthologs in H. mustelae, identifying a shared set of core proteins for gastric persistence. Conclusions The determination of the genome sequence and expressed proteome of the ulcerogenic species H mustelae provides a comparative model for H. pylori to investigate bacterial gastric carcinogenesis in mammals, and to suggest ways whereby cag minus H. pylori strains might cause ulceration and cancer. The genome sequence was

Comparative genomics and proteomics of Helicobacter mustelae, an ulcerogenic and carcinogenic gastric pathogen

LENUS (Irish Health Repository)

O'Toole, Paul W

2010-03-10

Abstract Background Helicobacter mustelae causes gastritis, ulcers and gastric cancer in ferrets and other mustelids. H. mustelae remains the only helicobacter other than H. pylori that causes gastric ulceration and cancer in its natural host. To improve understanding of H. mustelae pathogenesis, and the ulcerogenic and carcinogenic potential of helicobacters in general, we sequenced the H. mustelae genome, and identified 425 expressed proteins in the envelope and cytosolic proteome. Results The H. mustelae genome lacks orthologs of major H. pylori virulence factors including CagA, VacA, BabA, SabA and OipA. However, it encodes ten autotransporter surface proteins, seven of which were detected in the expressed proteome, and which, except for the Hsr protein, are of unknown function. There are 26 putative outer membrane proteins in H. mustelae, some of which are most similar to the Hof proteins of H. pylori. Although homologs of putative virulence determinants of H. pylori (NapA, plasminogen adhesin, collagenase) and Campylobacter jejuni (CiaB, Peb4a) are present in the H. mustelae genome, it also includes a distinct complement of virulence-related genes including a haemagglutinin\\/haemolysin protein, and a glycosyl transferase for producing blood group A\\/B on its lipopolysaccharide. The most highly expressed 264 proteins in the cytosolic proteome included many corresponding proteins from H. pylori, but the rank profile in H. mustelae was distinctive. Of 27 genes shown to be essential for H. pylori colonization of the gerbil, all but three had orthologs in H. mustelae, identifying a shared set of core proteins for gastric persistence. Conclusions The determination of the genome sequence and expressed proteome of the ulcerogenic species H mustelae provides a comparative model for H. pylori to investigate bacterial gastric carcinogenesis in mammals, and to suggest ways whereby cag minus H. pylori strains might cause ulceration and cancer. The genome sequence was

Let-7b is involved in the inflammation and immune responses associated with Helicobacter pylori infection by targeting Toll-like receptor 4.

Directory of Open Access Journals (Sweden)

Gui-gen Teng

Full Text Available OBJECTIVES: Toll-like receptors (TLRs are important initiators in native immune responses to microbial infections. TLR4 is up-regulated in response to H.pylori infection in gastric epithelial cells. However, the regulatory mechanisms for the expression of TLR4 in H.pylori infection have not been clearly defined. The aims of this study are to present the evidence that microRNA let-7b directly regulates TLR4 expression in human gastric epithelial cells, and subsequently influences the activation of NF-κB and the expression of the downstream genes in H.pylori infection. METHODS: The expression of let-7b was determined in gastric mucosa specimens and in two gastric epithelial cell lines using quantitative RT-PCR. The expression of TLR4 was determined by immunohistochemistry staining and RT-PCR. The potential target of let-7b was identified by luciferase reporter assay and Western blot. Let-7b mimics and inhibitors were used to examine the effects of let-7b on NF-κB activity. The expression of the downstream genes of NF-κB was also determined in cells infected with H.pylori 26695. RESULTS: Let-7b was significantly decreased in gastric mucosa specimens and in gastric epithelial cell lines (AGS, GES-1 infected with H.pylori 26695 (cagA+. Let-7b was complementary to the 3'-UTR of TLR4 mRNA and regulated TLR4 expression via post-transcriptional suppression in gastric epithelium. Infection of H.pylori induced the expression of TLR4 and activated NF-κB in AGS and GES-1 cells. Overexpression of let-7b by mimics downregulated TLR4, and subsequently attenuated NF-κB, MyD88, NF-κB1/p50, RelA/p65. The expression of IL-8, COX-2 and CyclinD1 was inhibited in H.pylori infected cells with let-7b overexpression. Both TAK-242 (TLR4 inhibitor and SN50 (NF-κB inhibitor significantly inhibited the H.pylori induced downregulation of let-7b. CONCLUSIONS: Let-7b targets at TLR4 mRNA, and regulates the activation of NF-κB and the expression of the downstream genes

The Haemophilus ducreyi LspA1 protein inhibits phagocytosis by using a new mechanism involving activation of C-terminal Src kinase.

Science.gov (United States)

Dodd, Dana A; Worth, Randall G; Rosen, Michael K; Grinstein, Sergio; van Oers, Nicolai S C; Hansen, Eric J

2014-05-20

Haemophilus ducreyi causes chancroid, a sexually transmitted infection. A primary means by which this pathogen causes disease involves eluding phagocytosis; however, the molecular basis for this escape mechanism has been poorly understood. Here, we report that the LspA virulence factors of H. ducreyi inhibit phagocytosis by stimulating the catalytic activity of C-terminal Src kinase (Csk), which itself inhibits Src family protein tyrosine kinases (SFKs) that promote phagocytosis. Inhibitory activity could be localized to a 37-kDa domain (designated YL2) of the 456-kDa LspA1 protein. The YL2 domain impaired ingestion of IgG-opsonized targets and decreased levels of active SFKs when expressed in mammalian cells. YL2 contains tyrosine residues in two EPIYG motifs that are phosphorylated in mammalian cells. These tyrosine residues were essential for YL2-based inhibition of phagocytosis. Csk was identified as the predominant mammalian protein interacting with YL2, and a dominant-negative Csk rescued phagocytosis in the presence of YL2. Purified Csk phosphorylated the tyrosines in the YL2 EPIYG motifs. Phosphorylated YL2 increased Csk catalytic activity, resulting in positive feedback, such that YL2 can be phosphorylated by the same kinase that it activates. Finally, we found that the Helicobacter pylori CagA protein also inhibited phagocytosis in a Csk-dependent manner, raising the possibility that this may be a general mechanism among diverse bacteria. Harnessing Csk to subvert the Fcγ receptor (FcγR)-mediated phagocytic pathway represents a new bacterial mechanism for circumventing a crucial component of the innate immune response and may potentially affect other SFK-involved cellular pathways. Phagocytosis is a critical component of the immune system that enables pathogens to be contained and cleared. A number of bacterial pathogens have developed specific strategies to either physically evade phagocytosis or block the intracellular signaling required for

Helicobacter pylori neutrophil-activating protein: A potential Treg modulator suppressing allergic asthma?

Directory of Open Access Journals (Sweden)

Anjna eSehrawat

2015-06-01

Full Text Available The ultimate aim of immunology is to kill the pathogen without being harmful to the host. But what if eliminating the pathogen in itself is discomforting for the host? One such emerging case is of Helicobacter pylori. Modern medicine, infantile vaccination and ultra-hygienic conditions have led to progressive disappearance of H. pylori in different parts of the world. However, the adversities caused by H. pylori’s absence are much larger than those caused by its presence. Asthma is rising as an epidemic in last few decades and several reports suggest an inverse-relationship between H. pylori’s persistence and early-life onset asthma. Regulatory T cells play an important role in both the cases. This is further supported by experiments on mouse-models. Hence, need of the hour is to discern the relationship between H. pylori and its host and eliminating its negative impacts without disturbing our indigenous microbiota. To resolve whether H. pylori is a pathogen or an amphibiont is another important side. This review explores the biological basis of H. pylori-induced priming of immune system offering resistance to childhood-onset asthma. HP-NAP-Tregs interaction has been predicted using molecular docking and dynamic simulation.

EGFR and Bcl-2 in gastric mucosa of children infected with Helicobacter pylori

Directory of Open Access Journals (Sweden)

Ewa Ryszczuk

2016-03-01

Full Text Available Aim: The aim of the study was to evaluate the expression of EGFR and Bcl-2 proteins as inhibitory markers of apoptosis in surface epithelial cells and gland cells of antral gastric mucosa in children infected with Helicobacter pylori according to the severity and activity of antral gastritis and to assess the correlation between the number of cells expressing EGFR and the number of cells expressing Bcl-2 in H. pylori infected children.Materials and methods: The study included 44 children: 68.2% with chronic gastritis and positive IgG against H. pylori, and 31.8% with functional disorders of the gastrointestinal tract and with normal IgG against H. pylori. The evaluation of EGFR expression in gastric mucosa was performed immunohistochemically using monoclonal mouse anti-EGFR antibody. The polyclonal antibody was used to determine the expression of anti-Bcl-2.Results: A significant increase in the number of cells expressing EGFR and Bcl-2 protein was found in the epithelial cells in severe as well as mild and moderate gastritis in the group of children infected with H. pylori. An increase in the number of cells expressing EGFR and Bcl-2 protein was also found in the epithelial cells in group I according to the activity of gastritis. There was a statistically significant positive correlation between the numbers of cells expressing EGFR and Bcl-2 in H. pylori infected children.Conclusion: Increased expression of EGFR and Bcl-2 proteins in the epithelial cells and a statistically significant positive correlation between the numbers of cells expressing EGFR and Bcl-2 in H. pylori infected children could suggest increased regeneration abilities of gastric mucosa.

Functional and evolutionary analyses of Helicobacter pylori HP0231 (DsbK protein with strong oxidative and chaperone activity characterized by a highly diverged dimerization domain

Directory of Open Access Journals (Sweden)

Katarzyna Marta Bocian-Ostrzycka

2015-10-01

Full Text Available Helicobacter pylori does not encode the classical DsbA/DsbB oxidoreductases that are crucial for oxidative folding of extracytoplasmic proteins. Instead, this microorganism encodes an untypical two proteins playing a role in disulfide bond formation – periplasmic HP0231, which structure resembles that of EcDsbC/DsbG, and its redox partner, a membrane protein HpDsbI (HP0595 with a -propeller structure. The aim of presented work was to assess relations between HP0231 structure and function.We showed that HP0231 is most closely related evolutionarily to the catalytic domain of DsbG, even though it possesses a catalytic motif typical for canonical DsbA proteins. Similarly, the highly diverged N-terminal dimerization domain is homologous to the dimerization domain of DsbG. To better understand the functioning of this atypical oxidoreductase, we examined its activity using in vivo and in vitro experiments. We found that HP0231 exhibits oxidizing and chaperone activities but no isomerizing activity, even though H. pylori does not contain a classical DsbC. We also show that HP0231 is not involved in the introduction of disulfide bonds into HcpC (Helicobacter cysteine-rich protein C, a protein involved in the modulation of the H. pylori interaction with its host. Additionally, we also constructed a truncated version of HP0231 lacking the dimerization domain, denoted HP0231m, and showed that it acts in E. coli cells in a DsbB-dependent manner. In contrast, HP0231m and classical monomeric EcDsbA (Escherichia coli DsbA protein were both unable to complement the lack of HP0231 in H. pylori cells, though they exist in oxidized forms. HP0231m is inactive in the insulin reduction assay and possesses high chaperone activity, in contrast to EcDsbA. In conclusion, HP0231 combines oxidative functions characteristic of DsbA proteins and chaperone activity characteristic of DsbC/DsbG, and it lacks isomerization activity.

Destructive effects of butyrate on the cell envelope of Helicobacter pylori.

Science.gov (United States)

Yonezawa, Hideo; Osaki, Takako; Hanawa, Tomoko; Kurata, Satoshi; Zaman, Cynthia; Woo, Timothy Derk Hoong; Takahashi, Motomichi; Matsubara, Sachie; Kawakami, Hayato; Ochiai, Kuniyasu; Kamiya, Shigeru

2012-04-01

Helicobacter pylori can be found in the oral cavity and is mostly detected by the use of PCR techniques. Growth of H. pylori is influenced by various factors in the mouth, such as the oral microflora, saliva and other antimicrobial substances, all of which make colonization of the oral cavity by H. pylori difficult. In the present study, we analysed the effect of the cell supernatant of a representative periodontal bacterium Porphyromonas gingivalis on H. pylori and found that the cell supernatant destroyed the H. pylori cell envelope. As P. gingivalis produces butyric acid, we focused our research on the effects of butyrate and found that it significantly inhibited the growth of H. pylori. H. pylori cytoplasmic proteins and DNA were detected in the extracellular environment after treatment with butyrate, suggesting that the integrity of the cell envelope was compromised and indicating that butyrate has a bactericidal effect on H. pylori. In addition, levels of extracellular H. pylori DNA increased following treatment with the cell supernatant of butyric acid-producing bacteria, indicating that the cell supernatant also has a bactericidal effect and that this may be due to its butyric acid content. In conclusion, butyric acid-producing bacteria may play a role in affecting H. pylori colonization of the oral cavity.

Repeat-associated plasticity in the Helicobacter pylori RD gene family.

Science.gov (United States)

Shak, Joshua R; Dick, Jonathan J; Meinersmann, Richard J; Perez-Perez, Guillermo I; Blaser, Martin J

2009-11-01

The bacterium Helicobacter pylori is remarkable for its ability to persist in the human stomach for decades without provoking sterilizing immunity. Since repetitive DNA can facilitate adaptive genomic flexibility via increased recombination, insertion, and deletion, we searched the genomes of two H. pylori strains for nucleotide repeats. We discovered a family of genes with extensive repetitive DNA that we have termed the H. pylori RD gene family. Each gene of this family is composed of a conserved 3' region, a variable mid-region encoding 7 and 11 amino acid repeats, and a 5' region containing one of two possible alleles. Analysis of five complete genome sequences and PCR genotyping of 42 H. pylori strains revealed extensive variation between strains in the number, location, and arrangement of RD genes. Furthermore, examination of multiple strains isolated from a single subject's stomach revealed intrahost variation in repeat number and composition. Despite prior evidence that the protein products of this gene family are expressed at the bacterial cell surface, enzyme-linked immunosorbent assay and immunoblot studies revealed no consistent seroreactivity to a recombinant RD protein by H. pylori-positive hosts. The pattern of repeats uncovered in the RD gene family appears to reflect slipped-strand mispairing or domain duplication, allowing for redundancy and subsequent diversity in genotype and phenotype. This novel family of hypervariable genes with conserved, repetitive, and allelic domains may represent an important locus for understanding H. pylori persistence in its natural host.

[Clinical significance of infection with cag A and vac A positive Helicobacter pylori strains].

Science.gov (United States)

Sokić-Milutinović, Aleksandra; Todorović, Vera; Milosavljević, Tomica

2004-01-01

Clinical relevance of infection with different Helicobacter pylori strains was reviewed in this paper. Helicobacter pylori (H. pylori) infection plays a role in pathogenesis of chronic gastritis, peptic ulcer disease, gastric adenocarcinoma and MALT lymphoma. Extragastric manifestations of H. pylori infection most probably include acne rosacea and chronic urticaria, while the importance of H. pylori infection for pathogenesis of growth retardation in children, iron deficiency anemia, coronary heart disease, stroke and idiopathic thrombocytopenic purpura remains vague. The expression of two H. pylori proteins, cytotoxin associated protein (cag A) and vacuolization cytotoxin (vac A) is considered to be related with pathogenicity of the bacterium. It is clear that presence of cag A+ strains is important for development of peptic ulcer; nevertheless, it is also protective against esophageal reflux disease. On the other hand, cag A+ strains are common in gastric adenocarcinoma and MALT lymphoma patients, but it seems that certain subtypes of vac A cytotoxin are more important risk factors. Infection with cag A+ strains is more common in patients with acne rosacea, stroke and coronary heart disease.

Clinical significance of infection with cag A and vac A positive helicobacter pylori strains

Directory of Open Access Journals (Sweden)

Sokić-Milutinović Aleksandra

2004-01-01

Full Text Available Clinical relevance of infection with different Helicobacter pylori strains was reviewed in this paper. Helicobacter pylori (H. pylori infection plays a role in pathogenesis of chronic gastritis, peptic ulcer disease, gastric adenocarcinoma and MALT lymphoma. Extragastric manifestations of H. pylori infection most probably include acne rosacea and chronic urticaria, while the importance of H. pylori infection for pathogenesis of growth retardation in children, iron deficiency anemia, coronary heart disease, stroke and idiopathic thrombocytopenic purpura remains vague. The expression of two H. pylori proteins, cytotoxin associated protein (cag A and vacuolization cytotoxin (vac A is considered to be related with pathogenicity of the bacterium. It is clear that presence of cag A+ strains is important for development of peptic ulcer; nevertheless, it is also protective against esophageal reflux disease. On the other hand, cag A+ strains are common in gastric adenocarcinoma and MALT lymphoma patients, but it seems that certain subtypes of vac A cytotoxin are more important risk factors. Infection with cag A+ strains is more common in patients with acne rosacea, stroke and coronary heart disease.

A pro-inflammatory role for Th22 cells in Helicobacter pylori-associated gastritis.

Science.gov (United States)

Zhuang, Yuan; Cheng, Ping; Liu, Xiao-fei; Peng, Liu-sheng; Li, Bo-sheng; Wang, Ting-ting; Chen, Na; Li, Wen-hua; Shi, Yun; Chen, Weisan; Pang, Ken C; Zeng, Ming; Mao, Xu-hu; Yang, Shi-ming; Guo, Hong; Guo, Gang; Liu, Tao; Zuo, Qian-fei; Yang, Hui-jie; Yang, Liu-yang; Mao, Fang-yuan; Lv, Yi-pin; Zou, Quan-ming

2015-09-01

Helper T (Th) cell responses are critical for the pathogenesis of Helicobacter pylori-induced gastritis. Th22 cells represent a newly discovered Th cell subset, but their relevance to H. pylori-induced gastritis is unknown. Flow cytometry, real-time PCR and ELISA analyses were performed to examine cell, protein and transcript levels in gastric samples from patients and mice infected with H. pylori. Gastric tissues from interleukin (IL)-22-deficient and wild-type (control) mice were also examined. Tissue inflammation was determined for pro-inflammatory cell infiltration and pro-inflammatory protein production. Gastric epithelial cells and myeloid-derived suppressor cells (MDSC) were isolated, stimulated and/or cultured for Th22 cell function assays. Th22 cells accumulated in gastric mucosa of both patients and mice infected with H. pylori. Th22 cell polarisation was promoted via the production of IL-23 by dendritic cells (DC) during H. pylori infection, and resulted in increased inflammation within the gastric mucosa. This inflammation was characterised by the CXCR2-dependent influx of MDSCs, whose migration was induced via the IL-22-dependent production of CXCL2 by gastric epithelial cells. Under the influence of IL-22, MDSCs, in turn, produced pro-inflammatory proteins, such as S100A8 and S100A9, and suppressed Th1 cell responses, thereby contributing to the development of H. pylori-associated gastritis. This study, therefore, identifies a novel regulatory network involving H. pylori, DCs, Th22 cells, gastric epithelial cells and MDSCs, which collectively exert a pro-inflammatory effect within the gastric microenvironment. Efforts to inhibit this Th22-dependent pathway may therefore prove a valuable strategy in the therapy of H. pylori-associated gastritis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Genetic microheterogeneity and phenotypic variation of Helicobacter pylori arginase in clinical isolates

Directory of Open Access Journals (Sweden)

Spadafora Domenico

2007-04-01

Full Text Available Abstract Background Clinical isolates of the gastric pathogen Helicobacter pylori display a high level of genetic macro- and microheterogeneity, featuring a panmictic, rather than clonal structure. The ability of H. pylori to survive the stomach acid is due, in part, to the arginase-urease enzyme system. Arginase (RocF hydrolyzes L-arginine to L-ornithine and urea, and urease hydrolyzes urea to carbon dioxide and ammonium, which can neutralize acid. Results The degree of variation in arginase was explored at the DNA sequence, enzyme activity and protein expression levels. To this end, arginase activity was measured from 73 minimally-passaged clinical isolates and six laboratory-adapted strains of H. pylori. The rocF gene from 21 of the strains was cloned into genetically stable E. coli and the enzyme activities measured. Arginase activity was found to substantially vary (>100-fold in both different H. pylori strains and in the E. coli model. Western blot analysis revealed a positive correlation between activity and amount of protein expressed in most H. pylori strains. Several H. pylori strains featured altered arginase activity upon in vitro passage. Pairwise alignments of the 21 rocF genes plus strain J99 revealed extensive microheterogeneity in the promoter region and 3' end of the rocF coding region. Amino acid S232, which was I232 in the arginase-negative clinical strain A2, was critical for arginase activity. Conclusion These studies demonstrated that H. pylori arginase exhibits extensive genotypic and phenotypic variation which may be used to understand mechanisms of microheterogeneity in H. pylori.

Construction of a recombinant Lactococcus lactis strain expressing a fusion protein of Omp22 and HpaA from Helicobacter pylori for oral vaccine development.

Science.gov (United States)

Zhang, Rongguang; Duan, Guangcai; Shi, Qingfeng; Chen, Shuaiyin; Fan, Qingtang; Sun, Nan; Xi, Yuanlin

2016-11-01

To develop orally administrated anti-Helicobacter pylori vaccination, a Lactococcus lactis strain was genetically constructed for fusion expression of H. pylori protective antigens HpaA and Omp22. The fusion gene of omp22 and hpaA with an adapter encoding three glycines was cloned from a plasmid pMAL-c2x-omp22-hpaA into Escherichia coli MC1061 and L. lactis NZ3900 successively using a shutter vector pNZ8110. Expression of the fusion gene in L. lactis was induced with nisin resulting in production of proteins with molecular weights of 50 and 28 kDa. Both of them were immunoreactive with mouse anti-H. pylori sera as determined via western blotting. Oral vaccination of BALB/c mice using the L. lactis strain carrying pNZ8110-omp22-hpaA elicited significant systematic humoral immune response (P lactis with immunogenicity. This is a considerable step towards H. pylori vaccines.

Phasevarion mediated epigenetic gene regulation in Helicobacter pylori.

Directory of Open Access Journals (Sweden)

Yogitha N Srikhanta

Full Text Available Many host-adapted bacterial pathogens contain DNA methyltransferases (mod genes that are subject to phase-variable expression (high-frequency reversible ON/OFF switching of gene expression. In Haemophilus influenzae and pathogenic Neisseria, the random switching of the modA gene, associated with a phase-variable type III restriction modification (R-M system, controls expression of a phase-variable regulon of genes (a "phasevarion", via differential methylation of the genome in the modA ON and OFF states. Phase-variable type III R-M systems are also found in Helicobacter pylori, suggesting that phasevarions may also exist in this key human pathogen. Phylogenetic studies on the phase-variable type III modH gene revealed that there are 17 distinct alleles in H. pylori, which differ only in their DNA recognition domain. One of the most commonly found alleles was modH5 (16% of isolates. Microarray analysis comparing the wild-type P12modH5 ON strain to a P12ΔmodH5 mutant revealed that six genes were either up- or down-regulated, and some were virulence-associated. These included flaA, which encodes a flagella protein important in motility and hopG, an outer membrane protein essential for colonization and associated with gastric cancer. This study provides the first evidence of this epigenetic mechanism of gene expression in H. pylori. Characterisation of H. pylori modH phasevarions to define stable immunological targets will be essential for vaccine development and may also contribute to understanding H. pylori pathogenesis.

Correlation analysis of riboflavin, RFT2 and Helicobater pylori in gastric carcinoma.

Science.gov (United States)

Matnuri, Muattar; Zheng, Chao; Sidik, Dildar; Bai, Ge; Abdukerim, Mamatjan; Abdukadier, Aliye; Ahmat, Kilara; Ma, Yue; Eli, Maynur

2015-01-01

To investigate the relationship between tissue riboflavin level and riboflavin transporter 2 (RFT2) protein expression, and the relationship between Helicobacter pylori (H.pylori) infection and the plasma riboflavin level in gastric carcinoma (GC). Enzyme-linked immunosorbent assay (ELISA) was used to detect tissue riboflavin level in patients with GC. Western blotting was applied to analyze the expression of RFT2 protein in 60 tissue samples from gastric carcinoma together with their normal tissues. The Warthin-starry method, rapid urease test and (14)C-UBT were administered to detect the infection of H.pylori. High performance liquid chromatography (H.PYLORILC) was performed to detect plasma riboflavin level in the GC. A significant decrease in the tissue riboflavin level was detected in GC samples compared to those in the normal mucous membrane (17.02 ± 3.91 vs. 21.0 ± 4.73; P = 0.043), and a significant decrease in the RFT2 protein was found in GC samples compared to those in the normal mucous membrane (0.92 ± 0.39 vs. 1.23 ± 0.51; P = 0.042). A positive correlation of tissue riboflavin level with defective expression of RFT2 protein was observed in GC patients (χ(2) = 1.969; P = 0.039). Plasma riboflavin level in gastric cancer without H.pylori infection group (1.6674 ng/mL ± 0.37009 ng/mL) was higher than H.pylori infection group (1.2207 ng/mL ± 0.17727 ng/mL, P = 0.043). The results indicate that RFT2 plays an important role in gastric carcinogenesis by modulating riboflavin absorption. H.pylori infection affects plasma riboflavin level and the prognosis of patients with gastric cancer.

Ebselen suppresses inflammation induced by Helicobacter pylori lipopolysaccharide via the p38 mitogen-activated protein kinase signaling pathway.

Science.gov (United States)

Xu, Ling; Gong, Changguo; Li, Guangming; Wei, Jue; Wang, Ting; Meng, Wenying; Shi, Min; Wang, Yugang

2018-05-01

Ebselen is a seleno-organic compound that has been demonstrated to have antioxidant and anti-inflammatory properties. A previous study determined that ebselen inhibits airway inflammation induced by inhalational lipopolysaccharide (LPS), however, the underlying molecular mechanism remains to be elucidated. The present study investigated the effect of ebselen on the glutathione peroxidase (GPX)‑reactive oxygen species (ROS) pathway and interleukin‑8 (IL‑8) expression induced by Helicobacter pylori LPS in gastric cancer (GC) cells. Cells were treated with 200 ng/ml H. pylori‑LPS in the presence or absence of ebselen for various durations and concentrations (µmol/l). The expression of toll‑like receptor 4 (TLR4), GPX2, GPX4, p38 mitogen‑activated protein kinase (p38 MAPK), phosphorylated‑p38 MAPK, ROS production and IL‑8 expression were detected with western blotting or ELISA. The present study revealed that TLR4 expression was upregulated; however, GPX2 and GPX4 expression was reduced following treatment with H. pylori LPS, which led to increased ROS production, subsequently altering the IL‑8 expression level in GC cells. Additionally, it was determined that ebselen prevented the reduction in GPX2/4 levels induced by H. pylori LPS, however, TLR4 expression was not affected. Ebselen may also block the expression of IL‑8 by inhibiting phosphorylation of p38 MAPK. These data suggest ebselen may inhibit ROS production triggered by H. pylori LPS treatment via GPX2/4 instead of TLR4 signaling and reduce phosphorylation of p38 MAPK, resulting in altered production of IL‑8. Ebselen may, therefore, be a potential therapeutic agent to mediate H. pylori LPS-induced cell damage.

Helicobacter pylori infection

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/007715.htm Helicobacter pylori infection To use the sharing features on this page, please enable JavaScript. Helicobacter pylori ( H pylori ) is a type of bacteria that ...

Protective effect of Korean Red Ginseng extract against Helicobacter pylori-induced gastric inflammation in Mongolian gerbils

Directory of Open Access Journals (Sweden)

Minkyung Bae

2014-01-01

Full Text Available Helicobacter pylori-induced gastric inflammation includes induction of inflammatory mediators interleukin (IL-8 and inducible nitric oxide synthase (iNOS, which are mediated by oxidant-sensitive transcription factor NF-κB. High levels of lipid peroxide (LPO and increased activity of myeloperoxidase (MPO, a biomarker of neutrophil infiltration, are observed in H. pylori-infected gastric mucosa. Panax ginseng Meyer, a Korean herb medicine, is widely used in Asian countries for its biological activities including anti-inflammatory efficacy. The present study aims to investigate whether Korean Red Ginseng extract (RGE inhibits H. pylori-induced gastric inflammation in Mongolian gerbils. One wk after intragastric inoculation with H. pylori, Mongolian gerbils were fed with either the control diet or the diet containing RGE (200 mg RGE/gerbil for 6 wk. The following were determined in gastric mucosa: the number of viable H. pylori in stomach; MPO activity; LPO level; mRNA and protein levels of keratinocyte chemoattractant factor (KC, a rodent IL-8 homolog, IL-1β, and iNOS; protein level of phospho-IκBα (which reflects the activation of NF-κB; and histology. As a result, RGE suppressed H. pylori-induced mRNA and protein levels of KC, IL-1β, and iNOS in gastric mucosa. RGE also inhibited H. pylori-induced phosphorylation of IκBα and increases in LPO level and MPO activity of gastric mucosa. RGE did not affect viable H. pylori colonization in the stomach, but improved the histological grade of infiltration of polymorphonuclear neutrophils, intestinal metaplasia, and hyperplasia. In conclusion, RGE inhibits H. pylori-induced gastric inflammation by suppressing induction of inflammatory mediators (KC, IL-1β, iNOS, MPO activity, and LPO level in H. pylori-infected gastric mucosa.

Cell-cycle inhibition by Helicobacter pylori L-asparaginase.

Directory of Open Access Journals (Sweden)

Claudia Scotti

Full Text Available Helicobacter pylori (H. pylori is a major human pathogen causing chronic gastritis, peptic ulcer, gastric cancer, and mucosa-associated lymphoid tissue lymphoma. One of the mechanisms whereby it induces damage depends on its interference with proliferation of host tissues. We here describe the discovery of a novel bacterial factor able to inhibit the cell-cycle of exposed cells, both of gastric and non-gastric origin. An integrated approach was adopted to isolate and characterise the molecule from the bacterial culture filtrate produced in a protein-free medium: size-exclusion chromatography, non-reducing gel electrophoresis, mass spectrometry, mutant analysis, recombinant protein expression and enzymatic assays. L-asparaginase was identified as the factor responsible for cell-cycle inhibition of fibroblasts and gastric cell lines. Its effect on cell-cycle was confirmed by inhibitors, a knockout strain and the action of recombinant L-asparaginase on cell lines. Interference with cell-cycle in vitro depended on cell genotype and was related to the expression levels of the concurrent enzyme asparagine synthetase. Bacterial subcellular distribution of L-asparaginase was also analysed along with its immunogenicity. H. pylori L-asparaginase is a novel antigen that functions as a cell-cycle inhibitor of fibroblasts and gastric cell lines. We give evidence supporting a role in the pathogenesis of H. pylori-related diseases and discuss its potential diagnostic application.

Repeat-Associated Plasticity in the Helicobacter pylori RD Gene Family▿ †

Science.gov (United States)

Shak, Joshua R.; Dick, Jonathan J.; Meinersmann, Richard J.; Perez-Perez, Guillermo I.; Blaser, Martin J.

2009-01-01

The bacterium Helicobacter pylori is remarkable for its ability to persist in the human stomach for decades without provoking sterilizing immunity. Since repetitive DNA can facilitate adaptive genomic flexibility via increased recombination, insertion, and deletion, we searched the genomes of two H. pylori strains for nucleotide repeats. We discovered a family of genes with extensive repetitive DNA that we have termed the H. pylori RD gene family. Each gene of this family is composed of a conserved 3′ region, a variable mid-region encoding 7 and 11 amino acid repeats, and a 5′ region containing one of two possible alleles. Analysis of five complete genome sequences and PCR genotyping of 42 H. pylori strains revealed extensive variation between strains in the number, location, and arrangement of RD genes. Furthermore, examination of multiple strains isolated from a single subject's stomach revealed intrahost variation in repeat number and composition. Despite prior evidence that the protein products of this gene family are expressed at the bacterial cell surface, enzyme-linked immunosorbent assay and immunoblot studies revealed no consistent seroreactivity to a recombinant RD protein by H. pylori-positive hosts. The pattern of repeats uncovered in the RD gene family appears to reflect slipped-strand mispairing or domain duplication, allowing for redundancy and subsequent diversity in genotype and phenotype. This novel family of hypervariable genes with conserved, repetitive, and allelic domains may represent an important locus for understanding H. pylori persistence in its natural host. PMID:19749042

Helicobacter pylori genomic microevolution during naturally occurring transmission between adults.

Directory of Open Access Journals (Sweden)

Bodo Linz

Full Text Available The human gastric pathogen Helicobacter pylori is usually acquired during childhood and, in the absence of treatment, chronic infection persists through most of the host's life. However, the frequency and importance of H. pylori transmission between adults is underestimated. Here we sequenced the complete genomes of H. pylori strains that were transmitted between spouses and analysed the genomic changes. Similar to H. pylori from chronic infection, a significantly high proportion of the determined 31 SNPs and 10 recombinant DNA fragments affected genes of the hop family of outer membrane proteins, some of which are known to be adhesins. In addition, changes in a fucosyltransferase gene modified the LPS component of the bacterial cell surface, suggesting strong diversifying selection. In contrast, virulence factor genes were not affected by the genomic changes. We propose a model of the genomic changes that are associated with the transmission and adaptation of H. pylori to a new human host.

Inflammation, Immunity, and Vaccines for Helicobacter pylori Infection

DEFF Research Database (Denmark)

Walduck, Anna; Andersen, Leif P; Raghavan, Sukanya

2015-01-01

studies that contribute with new insights in the host response to H. pylori infection. Also, the adaptive immune response to H. pylori and particularly the role of IL-22 have been addressed in some studies. These advances may improve vaccine development where new strategies have been published. Two major...... studies analyzed H. pylori genomes of 39 worldwide strains and looked at the protein profiles. In addition, multi-epitope vaccines for therapeutic use have been investigated. Studies on different adjuvants and delivery systems have also given us new insights. This review presents articles from the last...... year that reveal detailed insight into immunity and regulation of inflammation, the contribution of immune cells to the development of gastric cancer, and understanding mechanisms of vaccine-induced protection....

Helicobacter pylori-induced IL-33 modulates mast cell responses, benefits bacterial growth, and contributes to gastritis.

Science.gov (United States)

Lv, Yi-Pin; Teng, Yong-Sheng; Mao, Fang-Yuan; Peng, Liu-Sheng; Zhang, Jin-Yu; Cheng, Ping; Liu, Yu-Gang; Kong, Hui; Wang, Ting-Ting; Wu, Xiao-Long; Hao, Chuan-Jie; Chen, Weisan; Yang, Shi-Ming; Zhao, Yong-Liang; Han, Bin; Ma, Qiang; Zou, Quan-Ming; Zhuang, Yuan

2018-04-25

Interleukin (IL)-induced inflammatory responses are critical for the pathogenesis of Helicobacter pylori (H. pylori)-induced gastritis. IL-33 represents a recently discovered proinflammatory cytokine involved in inflammatory diseases, but its relevance to H. pylori-induced gastritis is unknown. Here, we found that gastric IL-33 mRNA and protein expression were elevated in gastric mucosa of both patients and mice infected with H. pylori, which is positively correlated with bacterial load and the degree of gastritis. IL-33 production was promoted via extracellular regulated protein kinases (ERK) signaling pathway activation by gastric epithelial cells in a cagA-dependent manner during H. pylori infection, and resulted in increased inflammation and bacteria burden within the gastric mucosa. Gastric epithelial cell-derived IL-33 promoted TNF-α production from mast cells in vitro, and IL-33 increased TNF-α production in vivo. Increased TNF-α inhibited gastric epithelial cell proliferation, conducing to the progress of H. pylori-associated gastritis and bacteria colonization. This study defined a patent regulatory networks involving H. pylori, gastric epithelial cell, IL-33, mast cell, and TNF-α, which jointly play a pathological effect within the gastric circumstances. It may be a valuable strategy to restrain this IL-33-dependent pathway in the treatment of H. pylori-associated gastritis.

Human lactoferrin increases Helicobacter pylori internalisation into AGS cells.

Science.gov (United States)

Coray, Dorien S; Heinemann, Jack A; Tyrer, Peter C; Keenan, Jacqueline I

2012-05-01

Helicobacter pylori has high global infection rates and can cause other undesirable clinical manifestations such as duodenal ulcer (DU) and gastric cancer (GC). Frequencies of re-infection after therapeutic clearance and rates of DU versus GC vary geographically and differ markedly between developed and developing countries, which suggests additional factors may be involved. The possibility that, in vivo, lactoferrin (Lf) may play a subtle role in modulating micronutrient availability or bacterial internalisation with implications for disease etiology is considered. Lf is an iron binding protein produced in mammals that has antimicrobial and immunomodulatory properties. Some bacteria that regularly colonise mammalian hosts have adapted to living in high Lf environments and we investigated if this included the gastric pathogen H. pylori. We found that H. pylori was able to use iron from fully iron-saturated human Lf (hLf) whereas partially iron-saturated hLf (apo) did not increase H. pylori growth. Instead, apo-hLf increased adherence to and internalisation of bacteria into cultured epithelial cells. By increasing internalisation, we speculate that apo-human lactoferrin may contribute to H. pylori's ability to persistence in the human stomach, an observation that potentially has implications for the risk of H. pylori-associated disease.

Comparative Analysis of two Helicobacter pylori Strains using Genomics and Mass Spectrometry-Based Proteomics

Directory of Open Access Journals (Sweden)

Roger Karlsson

2016-11-01

Full Text Available Helicobacter pylori, a gastroenteric pathogen believed to have co-evolved with humans over 100,000 years, shows significant genetic variability. This motivates the study of different H. pylori strains and the diseases they cause in order to identify determinants for disease evolution. In this study, we used proteomics tools to compare two H. pylori strains. Nic25_A was isolated in Nicaragua from a patient with intestinal metaplasia, and P12 was isolated in Europe from a patient with duodenal ulcers. Differences in the abundance of surface proteins between the two strains were determined with two mass spectrometry-based methods, label-free quantification (MaxQuant or the use of tandem mass tags (TMT. Each approach used a lipid-based protein immobilization (LPI™ technique to enrich peptides of surface proteins. Using the MaxQuant software, we found 52 proteins that differed significantly in abundance between the two strains (up- or downregulated by a factor of 1.5; with TMT, we found 18 proteins that differed in abundance between the strains. Strain P12 had a higher abundance of proteins encoded by the cag pathogenicity island, while levels of the acid response regulator ArsR and its regulatory targets (KatA, AmiE, and proteins involved in urease production were higher in strain Nic25_A. Our results show that differences in protein abundance between H. pylori strains can be detected with proteomic approaches; this could have important implications for the study of disease progression.

In vitro suppression of dendritic cells by Helicobacter pylori OipA.

Science.gov (United States)

Teymournejad, Omid; Mobarez, Ashraf M; Hassan, Zuhair M; Moazzeni, Seyed M; Ahmadabad, Hassan N

2014-04-01

Outer inflammatory protein A (OipA) has an important role in Helicobacter pylori pathogenesis. In this study, we purified the outer membrane protein and evaluated the effects of this protein on maturation and cytokine production by dendritic cells (DCs). The oipA gene was inserted into pET28a, and this construct was transformed into Escherichia coli BL21 (DE3). Purification of the recombinant protein was performed by Ni-NTA affinity chromatography. Immature DCs were purified from spleen of C57BL/6 mice with more than 90% purity and were treated with several concentrations of OipA (1-20 μg/mL) overnight. Expression of maturation markers (CD86, CD40, and MHC-II) on the surface of DCs and production of IL-10 and IL-12 were assessed by flow cytometry and ELISA, respectively. The expression of DC maturation markers CD40, CD86, and MHC-II was downregulated on the surface of OipA-treated DCs at concentrations of 10 and 20 μg/mL compared with negative control. Production of IL-10 decreases with increasing OipA concentration at a concentration of 5 μg/mL, but we detected no change in IL-12 production. Inability to eliminate H. pylori from stomach is partly due to the evasion of the bacteria from the immune response. DCs are central mediators between innate and adaptive immunity, and DC cytokines direct the types of adaptive immune response. This study indicated that OipA of H. pylori is a DC maturation suppression factor. Previous studies have shown that H. pylori manage tolerogenic programming in DCs leading to long-time gastric colonization. In conclusion, H. pylori OipA helps the establishment of chronic infection with reduction in IL-10 and suppression of DC maturation. © 2014 John Wiley & Sons Ltd.

Detection of H. Pylori infection on dyspepsia patients with IgA H. Pylori antibody

Science.gov (United States)

Loesnihari, R.

2018-03-01

Helicobacter pylori (H. pylori) has a big role in the relapse and pathogenesis of the upper gastrointestinal disease. Dyspepsia is characterized by uncomfortable feeling at the upper gastrointestinal area. IgA H. pylori antibody was in two-thirds of H. pylori infected patients, but about 7.2% of IgA H. Pylori antibody became the only positive result of the test between the two serology test (IgG and IgA). A cross-sectional study was conducted in 38 patients with dyspepsia. The IgA antibody test for H. pylori in the serum of dyspepsia patient conducted through the ELISA test. The hemoglobin levels, leukocytes, platelets number, and H. pylori infection via IgA antibody test on ulcer and non-ulcer dyspepsia patient had no significant difference. There was a relation between the number of platelets in the infected H. pylori patients compared to the non-infected patients. H. pylori infection in the ulcer and non-ulcer dyspepsia patient with serology method was 18%. H. pylori infection number on ulcer dyspepsia was not higher than the non-ulcer dyspepsia, all ulcer dyspepsia patients who were with H. pylori found with a lesion on the antrum.

Petri Net-Based Model of Helicobacter pylori Mediated Disruption of Tight Junction Proteins in Stomach Lining during Gastric Carcinoma

Directory of Open Access Journals (Sweden)

Anam Naz

2017-09-01

Full Text Available Tight junctions help prevent the passage of digestive enzymes and microorganisms through the space between adjacent epithelial cells lining. However, Helicobacter pylori encoded virulence factors negatively regulate these tight junctions and contribute to dysfunction of gastric mucosa. Here, we have predicted the regulation of important tight junction proteins, such as Zonula occludens-1, Claudin-2 and Connexin32 in the presence of pathogenic proteins. Molecular events such as post translational modifications and crosstalk between phosphorylation, O-glycosylation, palmitoylation and methylation are explored which may compromise the integrity of these tight junction proteins. Furthermore, the signaling pathways disrupted by dysregulated kinases, proteins and post-translational modifications are reviewed to design an abstracted computational model showing the situation-dependent dynamic behaviors of these biological processes and entities. A qualitative hybrid Petri Net model is therefore constructed showing the altered host pathways in the presence of virulence factor cytotoxin-associated gene A, leading to the disruption of tight junction proteins. The model is qualitative logic-based, which does not depend on any kinetic parameter and quantitative data and depends on knowledge derived from experiments. The designed model provides insights into the tight junction disruption and disease progression. Model is then verified by the available experimental data, nevertheless formal in vitro experimentation is a promising way to ensure its validation. The major findings propose that H. pylori activated kinases are responsible to trigger specific post translational modifications within tight junction proteins, at specific sites. These modifications may favor alterations in gastric barrier and provide a route to bacterial invasion into host cells.

Immunodominant antigens of Helicobacter pylori strains isolated from patients with different gastroduodenal diseases

International Nuclear Information System (INIS)

Farshad, S.; Alborzi, A.; Japoni, A.; Hayati, M.; Nasiri, J.; Rafatpour, N.; Saberfirouzi, M.; Lankarani, Kamran B.; Taghavi, Ali R.; Irajian, Gholam R.

2006-01-01

To detect the immunogenic proteins in Helicobacter pylori (H. pylori) strains isolated from patients with different gastric diseases. We performed this study in the Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran, during July 2003 to September 2004. Total proteins of H. pylori strains isolated from the gastric biopsies of 3 groups of patients were separated by 1D-SDS-PAGE and then blotted with the sera of their respective hosts. In SDS-PAGE the members of each group showed high correlation according to similarity in their patterns, resulting in considering them in the same cluster. The patterns of immunoblots differed from that of Coomassie Brilliant Blue stained gels. The blotting method did not recognize some of the protein bands in the SDS-PAGE. Only the bands of 106 and 45 kDa from H. pylori strains isolated from patients with gastric cancer were significantly (p<0.05) recognized specifically with the sera of their respective patients, and the band of 13 kDa was recognized specifically (p<0.05) with the sera of nonulceric patients. With the exception of these bands, in the patterns of blotting of the sera from all patients no significant differences were observed. By using 1D blotting methods we could find 2 antigenic protein bands (106 and 45 kDa) for H. pylori strains isolated from cancerous patients, and one (13 kDa) for the strains isolated from nonulceric patients, which were specifically recognized with their respective host. (author)

Screening of E. coli β-clamp Inhibitors Revealed that Few Inhibit Helicobacter pylori More Effectively: Structural and Functional Characterization

Directory of Open Access Journals (Sweden)

Preeti Pandey

2018-01-01

Full Text Available The characteristic of interaction with various enzymes and processivity-promoting nature during DNA replication makes β-clamp an important drug target. Helicobacter pylori (H. pylori have several unique features in DNA replication machinery that makes it different from other microorganisms. To find out whether difference in DNA replication proteins behavior accounts for any difference in drug response when compared to E. coli, in the present study, we have tested E. coli β-clamp inhibitor molecules against H. pylori β-clamp. Various approaches were used to test the binding of inhibitors to H. pylori β-clamp including docking, surface competition assay, complex structure determination, as well as antimicrobial assay. Out of five shortlisted inhibitor molecules on the basis of docking score, three molecules, 5-chloroisatin, carprofen, and 3,4-difluorobenzamide were co-crystallized with H. pylori β-clamp and the structures show that they bind at the protein-protein interaction site as expected. In vivo studies showed only two molecules, 5-chloroisatin, and 3,4-difluorobenzamide inhibited the growth of the pylori with MIC values in micro molar range, which is better than the inhibitory effect of the same drugs on E. coli. Therefore, the evaluation of such drugs against H. pylori may explore the possibility to use to generate species-specific pharmacophore for development of new drugs against H. pylori.

Screening of E. coli β-clamp Inhibitors Revealed that Few Inhibit Helicobacter pylori More Effectively: Structural and Functional Characterization.

Science.gov (United States)

Pandey, Preeti; Verma, Vijay; Dhar, Suman Kumar; Gourinath, Samudrala

2018-01-11

The characteristic of interaction with various enzymes and processivity-promoting nature during DNA replication makes β-clamp an important drug target. Helicobacter pylori ( H. pylori ) have several unique features in DNA replication machinery that makes it different from other microorganisms. To find out whether difference in DNA replication proteins behavior accounts for any difference in drug response when compared to E. coli , in the present study, we have tested E. coli β-clamp inhibitor molecules against H. pylori β-clamp. Various approaches were used to test the binding of inhibitors to H. pylori β-clamp including docking, surface competition assay, complex structure determination, as well as antimicrobial assay. Out of five shortlisted inhibitor molecules on the basis of docking score, three molecules, 5-chloroisatin, carprofen, and 3,4-difluorobenzamide were co-crystallized with H. pylori β-clamp and the structures show that they bind at the protein-protein interaction site as expected. In vivo studies showed only two molecules, 5-chloroisatin, and 3,4-difluorobenzamide inhibited the growth of the pylori with MIC values in micro molar range, which is better than the inhibitory effect of the same drugs on E. coli . Therefore, the evaluation of such drugs against H. pylori may explore the possibility to use to generate species-specific pharmacophore for development of new drugs against H. pylori .

Helicobacter pylori gastritis

International Nuclear Information System (INIS)

Urban, B.A.; Fishman, E.K.; Kuhlman, J.E.; Jones, B.

1990-01-01

This paper reports on the CT scans of patients with Helicobacter pylori (formerly Campylobacter pylori) infection and histologic gastritis reviewed to determine if the inflammatory changes can mimic the CT appearance of gastric neoplasm. Records were obtained of 288 consecutive cases of biopsy-confirmed. Helicobacter pylori gastritis, spanning a 21-month period from July 1988 to March 1990. Abdominal CT scans had been performed in 70 of these cases and were retrospectively reviewed. RESULTS: Seven of the 70 cases of confirmed Helicobacter pylori gastritis were suggestive of malignancy on CT

Ureases display biological effects independent of enzymatic activity: Is there a connection to diseases caused by urease-producing bacteria?

Directory of Open Access Journals (Sweden)

D. Olivera-Severo

2006-07-01

Full Text Available Ureases are enzymes from plants, fungi and bacteria that catalyze the hydrolysis of urea to form ammonia and carbon dioxide. While fungal and plant ureases are homo-oligomers of 90-kDa subunits, bacterial ureases are multimers of two or three subunit complexes. We showed that some isoforms of jack bean urease, canatoxin and the classical urease, bind to glycoconjugates and induce platelet aggregation. Canatoxin also promotes release of histamine from mast cells, insulin from pancreatic cells and neurotransmitters from brain synaptosomes. In vivo it induces rat paw edema and neutrophil chemotaxis. These effects are independent of ureolytic activity and require activation of eicosanoid metabolism and calcium channels. Helicobacter pylori, a Gram-negative bacterium that colonizes the human stomach mucosa, causes gastric ulcers and cancer by a mechanism that is not understood. H. pylori produces factors that damage gastric epithelial cells, such as the vacuolating cytotoxin VacA, the cytotoxin-associated protein CagA, and a urease (up to 10% of bacterial protein that neutralizes the acidic medium permitting its survival in the stomach. H. pylori whole cells or extracts of its water-soluble proteins promote inflammation, activate neutrophils and induce the release of cytokines. In this paper we review data from the literature suggesting that H. pylori urease displays many of the biological activities observed for jack bean ureases and show that bacterial ureases have a secretagogue effect modulated by eicosanoid metabolites through lipoxygenase pathways. These findings could be relevant to the elucidation of the role of urease in the pathogenesis of the gastrointestinal disease caused by H. pylori.

Association of polymorphisms in virulence factor of Helicobacter pylori and gastroduodenal diseases in South Korea.

Science.gov (United States)

Kim, Ji Yeon; Kim, Nayoung; Nam, Ryoung Hee; Suh, Ji Hyung; Chang, Hyun; Lee, Jung Won; Kim, Young Sun; Kim, Jung Mogg; Choi, Jae Won; Park, Jung Geun; Lee, Yeon Suk; Lee, Dong Ho; Jung, Hyun Chae

2014-05-01

Clinical outcomes of Helicobacter pylori (HP) infection have been shown to be dependent on the variability of virulence factors. The aim of this study was to evaluate the prevalence of each virulence factor and the association between polymorphisms of the virulence factors of HP, and the clinical outcome of gastroduodenal diseases in South Korea. Four hundred one HP colonies were analyzed (75 colonies from 45 controls; 71 colonies from 39 benign gastric ulcer [BGU] patients; 102 colonies from 54 duodenal ulcer [DU] patients; 121 colonies from 77 stomach cancer patients; and 32 colonies from 25 dysplasia patients). Polymerase chain reaction amplifications for vacA, cagA, iceA, oipA, and dupA were performed using DNA extract from HP isolates cultured from mucosal biopsy specimens. dupA was regarded as positive when all of jph0718, jph0719, and dupA were positive. Most colonies were composed of vacA s1 (100.0%), i1 (100.0%) and m1 (92.9%), cagA-positive (87.2%), iceA1 (95.8%), oipA-positive (91.2%), and dupA-negative (52.0%) genotypes. dupA was more frequently expressed in BGU (81.3%), DU (74.7%), and dysplasia (41.7%) than control (16.7%) (P dupA-positive HP showed an increased risk of BGU (odds ratio 33.06, 95% confidence interval 11.91-91.79) and DU (odds ratio 15.60, 95% confidence interval 6.49-37.49). HP infection in South Koreans appears to be closely related to highly virulent strains (vacA s1/i1/m1, cagA(+), iceA1(+), and oipA(+)), except dupA. dupA has an intimate association with the development of peptic ulcer diseases. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

Pleiotropic Actions of Helicobacter pylori Vacuolating Cytotoxin, VacA

OpenAIRE

Isomoto, Hajime; Moss, Joel; Hirayama, Toshiya

2010-01-01

Helicobacter pylori produces a vacuolating cytotoxin, VacA, and most virulent H. pylori strains secrete VacA. VacA binds to two types of receptor-like protein tyrosine phosphatase (RPTP), RPTPα and RPTPβ, on the surface of host cells. VacA bound to RPTPβ, relocates and concentrates in lipid rafts in the plasma membrane. VacA causes vacuolization, membrane anion-selective channel and pore formation, and disruption of endosomal and lysosomal activity in host cells. Secreted VacA is processed in...

Helicobacter pylori and nonmalignant diseases.

LENUS (Irish Health Repository)

Alakkari, Alaa

2012-02-01

Research published over the past year has documented the continued decline of Helicobacter pylori-related peptic ulcer disease and increased recognition of non-H. pylori, non-steroidal anti-inflammatory drugs ulcer disease--idiopathic ulcers. Despite reduced prevalence of uncomplicated PUD, rates of ulcer complications and associated mortality remain stubbornly high. The role of H. pylori in functional dyspepsia is unclear, with some authors considering H. pylori-associated nonulcer dyspepsia a distinct organic entity. There is increasing acceptance of an inverse relationship between H. pylori and gastroesophageal reflux disease (GERD), but little understanding of how GERD might be more common\\/severe in H. pylori-negative subjects. Research has focused on factors such as different H. pylori phenotypes, weight gain after H. pylori eradication, and effects on hormones such as ghrelin that control appetite.

Microaerophilic conditions permit to mimic in vitro events occurring during in vivo Helicobacter pylori infection and to identify Rho/Ras-associated proteins in cellular signaling.

Science.gov (United States)

Cottet, Sandra; Corthésy-Theulaz, Irène; Spertini, François; Corthésy, Blaise

2002-09-13

Molecular dissection of the mechanisms underlying Helicobacter pylori infection suffers from the lack of in vitro systems mimicking in vivo observations. A system was developed whereby human epithelial cells (Caco-2) grown as polarized monolayers and bacteria can communicate with each other under culture conditions optimal for each partner. Caco-2 cells grown on filter supports were inserted in a vertical position into diffusion chambers equilibrated with air and 5% CO(2) at their basolateral surface (aerophilic conditions) and 5% CO(2), 5% O(2), 90% N(2) (microaerophilic conditions) in the apical compartment. Remarkably, the epithelial polarized layer was stable under these asymmetric culture conditions for at least 24 h, and the presence of Caco-2 cells was necessary to maintain H. pylori growth. In contrast to previous studies conducted with non-polarized Caco-2 cells and other cell lines kept under aerophilic conditions, we found H. pylori-dependent stimulation of cytokine secretion (MCP-1 (monocyte chemoattractant protein-1), GRO-alpha (growth-regulated oncogene-alpha), RANTES (regulated on activation normal T cell expressed and secreted)). This correlated with nuclear translocation of NF-kappaB p50 and p65 subunits. Tyrosine phosphorylation of nine cellular proteins was induced or enhanced; we identified p120(RasGAP), p190(RhoGAP), p62dok (downstream of tyrosine kinases), and cortactin as H. pylori-inducible targets. Moreover, reduction of H. pylori urease expression was observed in adherent bacteria as compared with bacteria in suspension. In addition to mimicking several observations seen in the inflamed gastric mucosa, the novel in vitro system was allowed to underscore complex cellular events not seen in classical in vitro analyses of microaerophilic bacteria-epithelial cell cross-talk.

Association of Intact dupA (dupA1) rather than dupA1 cluster with duodenal ulcer in Indian population.

Science.gov (United States)

Alam, Jawed; Ghosh, Prachetash; Ganguly, Mou; Sarkar, Avijit; De, Ronita; Mukhopadhyay, Asish K

2015-01-01

The duodenal ulcer promoting gene (dupA) and dupA cluster in Helicobacter pylori have been described as a risk factor for duodenal ulcer development in some populations. Polymorphic gene dupA can be divided into two groups, intact dupA1 (long or short type based on the presence or absence of 615-bp extra sequences at the 5' region) having complete reading frame and other truncated dupA2 having frame-shift mutation. This study was aimed to elucidate the role of dupA of H. pylori and their clusters in the disease manifestation of Indian population. A total of 170 H. pylori strains were screened for the presence of dupA, dupA alleles and dupA cluster by PCR and sequencing. Pro-inflammatory cytokine (IL-8) with different dupA variant H. pylori stimulated gastric epithelial cells (AGS cells) was measured by ELISA. A total of 50 strains (29.4%) were positive for dupA among the tested 170 strains. The prevalence of dupA1 in duodenal ulcer (DU) and non-ulcer dyspepsia (NUD) populations was found to be 25.5% (25/98) and 11.1% (8/72), respectively and 16.4% (28/170) of the tested strains had dupA1, cagA and vacAs1m1 positive. The distribution of long and short type dupA1 has not been significantly associated with the disease outcome. The dupA cluster analysis showed that 10.2% (10/98) and 8.3% (6/72) strains were positive among DU and NUD, respectively. IL-8 production was significantly higher in dupA1(+) , cagA (+), vacA (+) (902.5 ± 79.01 pg/mL) than dupA2 (+) , cagA (+) , vacA (+) (536.0 ± 100.4 pg/mL, P = 0.008) and dupA (-), cagA (+), vacA (+) (549.7 ± 104.1 pg/mL, P = 0.009). Phylogenetic analysis of dupA indicated that the Indian H. pylori strains clustered with East Asian strains but distinct from Western strains. This is the first known genetic element of Indian H. pylori that is genetically closer to the East Asian strains but differed from the Western strains. The intact dupA1 was significantly associated with DU than NUD (P = 0

Helicobacter pylori vaccine: from past to future.

Science.gov (United States)

Agarwal, Kanishtha; Agarwal, Shvetank

2008-02-01

Helicobacter pylori infection is highly prevalent worldwide and is an important cause of gastritis, peptic ulcer disease, gastric mucosa-associated lymphoid tissue lymphoma (MALToma), and gastric adenocarcinoma. Infection is usually acquired during childhood and tends to persist unless treated. Because eradication requires treatment with multidrug regimens, prevention of initial infection by a suitable vaccine is attractive. Although immunization with H pylori protein subunits has been encouraging in animals, similar vaccine trials in humans have shown adjuvant-related adverse effects and only moderate effectiveness. Newer immunization approaches (use of DNA, live vectors, bacterial ghosts, and microspheres) are being developed. Several questions about when and whom to vaccinate will need to be appropriately answered, and a cost-effective vaccine production and delivery strategy will have to be useful for developing countries. For this review, we searched MEDLINE using the Medical Subject Heading (MeSH) terms Helicobacter pylori and vaccines for articles in English from 1990 to 2007.

Microevolution of Virulence-Related Genes in Helicobacter pylori Familial Infection.

Directory of Open Access Journals (Sweden)

Yoshikazu Furuta

Full Text Available Helicobacter pylori, a bacterial pathogen that can infect human stomach causing gastritis, ulcers and cancer, is known to have a high degree of genome/epigenome diversity as the result of mutation and recombination. The bacteria often infect in childhood and persist for the life of the host. One of the reasons of the rapid evolution of H. pylori is that it changes its genome drastically for adaptation to a new host. To investigate microevolution and adaptation of the H. pylori genome, we undertook whole genome sequencing of the same or very similar sequence type in multi-locus sequence typing (MLST with seven genes in members of the same family consisting of parents and children in Japan. Detection of nucleotide substitutions revealed likely transmission pathways involving children. Nonsynonymous (amino acid changing mutations were found in virulence-related genes (cag genes, vacA, hcpDX, tnfα, ggt, htrA and the collagenase gene, outer membrane protein (OMP genes and other cell surface-related protein genes, signal transduction genes and restriction-modification genes. We reconstructed various pathways by which H. pylori can adapt to a new human host, and our results raised the possibility that the mutational changes in virulence-related genes have a role in adaptation to a child host. Changes in restriction-modification genes might remodel the methylome and transcriptome to help adaptation. This study has provided insights into H. pylori transmission and virulence and has implications for basic research as well as clinical practice.

Use of Random and Site-Directed Mutagenesis to Probe Protein Structure-Function Relationships: Applied Techniques in the Study of Helicobacter pylori.

Science.gov (United States)

Whitmire, Jeannette M; Merrell, D Scott

2017-01-01

Mutagenesis is a valuable tool to examine the structure-function relationships of bacterial proteins. As such, a wide variety of mutagenesis techniques and strategies have been developed. This chapter details a selection of random mutagenesis methods and site-directed mutagenesis procedures that can be applied to an array of bacterial species. Additionally, the direct application of the techniques to study the Helicobacter pylori Ferric Uptake Regulator (Fur) protein is described. The varied approaches illustrated herein allow the robust investigation of the structural-functional relationships within a protein of interest.

Helicobacter pylori genetic diversification in the Mongolian gerbil model.

Science.gov (United States)

Beckett, Amber C; Loh, John T; Chopra, Abha; Leary, Shay; Lin, Aung Soe; McDonnell, Wyatt J; Dixon, Beverly R E A; Noto, Jennifer M; Israel, Dawn A; Peek, Richard M; Mallal, Simon; Algood, Holly M Scott; Cover, Timothy L

2018-01-01

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

A study on the effect of Helicobacter pylori infection on p53 expression in gastric cancer and gastritis tissues.

Science.gov (United States)

Salih, Barik A; Gucin, Zuhal; Bayyurt, Nizamettin

2013-09-16

Helicobacter pylori cause damage to gastric epithelial cells and alterations in the p53 gene that lead to cancer development. This study aimed to determine the correlation of p53 expression with H. pylori using immunohistochemistry, RFLP-PCR, and histopathology. Gastric biopsy samples from gastric cancer (GC) (n = 54) and gastritis (n = 31) patients were examined for histopathological changes and expression of p53 protein by immunohistochemistry. Immunohistochemical analysis of p53 protein expression in H. pylori-positive GC sections showed an average of 44.3% positive cells in tumors and 6.9% in normal tissues, as compared to 16.4% and 4.4% in H. pylori-negative sections. P53 expression showed significant association with H. pylori (P = 0.005), invasion depth (P = 0.029) and inflammation reaction (P = 0.008). In gastritis sections, no difference in the average p53 staining in H. pylori-positive or -negative sections was seen. PCR-RFLP results also showed no difference in genotype frequencies of p53 in H. pylori-positive or -negative gastritis sections. Histopathology study of H. pylori-positive GC sections showed that 97.2% were the intestinal type and 2.8% the diffuse type, while in H. pylori-negative sections 35.2% were the intestinal type and 64.8% the diffuse type. Biopsy sections from H. pylori-positive gastritis patients revealed more severe inflammation than those of H. pylori-negative patients. Our results show that H. pylori infection affects p53 expression in GC. The average p53 expression was significantly higher in tumor than in normal tissues. In gastritis sections p53 expression was significantly associated with H. pylori.

Low concentrations of zinc in gastric mucosa are associated with increased severity of Helicobacter pylori-induced inflammation.

Science.gov (United States)

Sempértegui, Fernando; Díaz, Myriam; Mejía, Ricardo; Rodríguez-Mora, Oswaldo G; Rentería, Edgar; Guarderas, Carlos; Estrella, Bertha; Recalde, Ramiro; Hamer, Davidson H; Reeves, Philip G

2007-02-01

Chronic Helicobacter pylori infection is the most common cause of gastric cancer. H. pylori induces oxidative stress while zinc deficiency results in increased sensitivity to it. In Ecuador, the prevalence of gastric cancer and zinc deficiency are high. We hypothesized that zinc deficiency in Ecuadorian people would cause increased H. pylori-induced inflammation in the gastric mucosa associated with lower tissue zinc concentrations. Three hundred and fifty-two patients with dyspepsia underwent endoscopy to obtain gastric mucosa biopsies. Diagnosis of H. pylori infection and its severity, histopathology, mucosal zinc concentration, and inflammation intensity were determined. H. pylori-infected patients with non-atrophic chronic gastritis had lower concentrations of zinc in gastric mucosa than uninfected patients with the same type of gastritis (251.3 +/- 225.3 vs. 426.2 +/- 279.9 ng/mg of protein; p = .016). Considering all patients, the more severe the H. pylori infection, the higher the percentage of subjects with infiltration by polymorphonuclear (PMN) cells (p = .0001). Patients with high PMN infiltration had lower mucosal zinc concentrations than patients with low PMN infiltration (35.2 +/- 20.7 vs. 242.9 +/- 191.8 ng/mg of protein; p = .021). The degree of inflammation in H. pylori-induced gastritis appears to be modulated by gastric tissue zinc concentrations.

Outer membrane biogenesis in Escherichia coli, Neisseria meningitidis, and Helicobacter pylori: paradigm deviations in H. pylori.

Science.gov (United States)

Liechti, George; Goldberg, Joanna B

2012-01-01

The bacterial pathogen Helicobacter pylori is capable of colonizing the gastric mucosa of the human stomach using a variety of factors associated with or secreted from its outer membrane (OM). Lipopolysaccharide (LPS) and numerous OM proteins have been shown to be involved in adhesion and immune stimulation/evasion. Many of these factors are essential for colonization and/or pathogenesis in a variety of animal models. Despite this wide array of potential targets present on the bacterial surface, the ability of H. pylori to vary its OM profile limits the effectiveness of vaccines or therapeutics that target any single one of these components. However, it has become evident that the proteins comprising the complexes that transport the majority of these molecules to the OM are highly conserved and often essential. The field of membrane biogenesis has progressed remarkably in the last few years, and the possibility now exists for targeting the mechanisms by which β-barrel proteins, lipoproteins, and LPS are transported to the OM, resulting in loss of bacterial fitness and significant altering of membrane permeability. In this review, the OM transport machinery for LPS, lipoproteins, and outer membrane proteins (OMPs) are discussed. While the principal investigations of these transport mechanisms have been conducted in Escherichia coli and Neisseria meningitidis, here these systems will be presented in the genetic context of ε proteobacteria. Bioinformatic analysis reveals that minimalist genomes, such as that of Helicobacter pylori, offer insight into the smallest number of components required for these essential pathways to function. Interestingly, in the majority of ε proteobacteria, while the inner and OM associated apparatus of LPS, lipoprotein, and OMP transport pathways appear to all be intact, most of the components associated with the periplasmic compartment are either missing or are almost unrecognizable when compared to their E. coli counterparts. Eventual

Evaluation of SD BIOLINE H. pylori Ag rapid test against double ELISA with SD H. pylori Ag ELISA and EZ-STEP H. pylori Ag ELISA tests.

Science.gov (United States)

Negash, Markos; Kassu, Afework; Amare, Bemnet; Yismaw, Gizachew; Moges, Beyene

2018-01-01

Helicobacter pylori antibody titters fall very slowly even after successful treatment. Therefore, tests detecting H. pylori antibody lack specificity and sensitivity. On the other hand, H. pylori stool antigen tests are reported as an alternative assay because of their reliability and simplicity. However, the comparative performance of H. pylori stool antigen tests for detecting the presence of the bacterium in clinical specimens in the study area is not assessed. Therefore, in this study we evaluated the performance of SD BIOLINE H. pylori Ag rapid test with reference to the commercially available EZ- STEP ELISA and SD BIOLINE H. pylori Ag ELISA tests. Stool samples were collected to analyse the diagnostic performance of SD BIOLINE H. pylori Ag rapid test kit using SD H. pylori Ag ELISA kit and EZ- STEP ELISA tests as a gold standard. Serum samples were also collected from each patient to test for the presence of H. pylori antibodies using dBest H. pylori Test Disk. Sensitivity, specificity, predictive values and kappa value are assessed. P values H. pylori Ag rapid test were: 95.6% (95% CI, 88.8-98.8), 92.5% (95%CI, 89-94.1%), 86.7% (95% CI, 80.5-89.6), and 97.6% (95% CI, 993.9-99.3) respectively. The performance of SD BIOLINE H. pylori Ag rapid test was better than the currently available antibody test in study area. Therefore, the SD BIOLINE Ag rapid stool test could replace and be used to diagnose active H. pylori infection before the commencement of therapy among dyspeptic patients.

Crystal structure of Helicobacter pylori neutrophil-activating protein with a di-nuclear ferroxidase center in a zinc or cadmium-bound form

Energy Technology Data Exchange (ETDEWEB)

Yokoyama, Hideshi, E-mail: h-yokoya@u-shizuoka-ken.ac.jp [School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526 (Japan); Tsuruta, Osamu; Akao, Naoya; Fujii, Satoshi [School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526 (Japan)

2012-06-15

Highlights: Black-Right-Pointing-Pointer Structures of a metal-bound Helicobacter pylori neutrophil-activating protein were determined. Black-Right-Pointing-Pointer Two zinc ions were tetrahedrally coordinated by ferroxidase center (FOC) residues. Black-Right-Pointing-Pointer Two cadmium ions were coordinated in a trigonal-bipyramidal and octahedral manner. Black-Right-Pointing-Pointer The second metal ion was more weakly coordinated than the first at the FOC. Black-Right-Pointing-Pointer A zinc ion was found in one negatively-charged pore suitable as an ion path. -- Abstract: Helicobacter pylori neutrophil-activating protein (HP-NAP) is a Dps-like iron storage protein forming a dodecameric shell, and promotes adhesion of neutrophils to endothelial cells. The crystal structure of HP-NAP in a Zn{sup 2+}- or Cd{sup 2+}-bound form reveals the binding of two zinc or two cadmium ions and their bridged water molecule at the ferroxidase center (FOC). The two zinc ions are coordinated in a tetrahedral manner to the conserved residues among HP-NAP and Dps proteins. The two cadmium ions are coordinated in a trigonal-bipyramidal and distorted octahedral manner. In both structures, the second ion is more weakly coordinated than the first. Another zinc ion is found inside of the negatively-charged threefold-related pore, which is suitable for metal ions to pass through.

Re-annotation of the genome sequence of Helicobacter pylori 26695

Directory of Open Access Journals (Sweden)

Resende Tiago

2013-12-01

Full Text Available Helicobacter pylori is a pathogenic bacterium that colonizes the human epithelia, causing duodenal and gastric ulcers, and gastric cancer. The genome of H. pylori 26695 has been previously sequenced and annotated. In addition, two genome-scale metabolic models have been developed. In order to maintain accurate and relevant information on coding sequences (CDS and to retrieve new information, the assignment of new functions to Helicobacter pylori 26695s genes was performed in this work. The use of software tools, on-line databases and an annotation pipeline for inspecting each gene allowed the attribution of validated EC numbers and TC numbers to metabolic genes encoding enzymes and transport proteins, respectively. 1212 genes encoding proteins were identified in this annotation, being 712 metabolic genes and 500 non-metabolic, while 191 new functions were assignment to the CDS of this bacterium. This information provides relevant biological information for the scientific community dealing with this organism and can be used as the basis for a new metabolic model reconstruction.

Role of adjuvant therapy in the treatment of helicobacter pylori infection in children

Directory of Open Access Journals (Sweden)

Gerasymenko O.N.

2014-06-01

Full Text Available The aim was to study the effect of combined probiotic containing Lactobacillus acidophilus, Bifidobacterium infantis, Enterococcus faecium, on H.pylori eradication efficacy in the treatment of children with chronic H.pylori- associated gastroduodenitis in the scheme of "triple" therapy of H.pylori eradication. Determination of total serum Ig M , A, G protein to Ag SagA H. pylori, breathing "Helik" test, rapid urease "Helpil" test ; that of concentration of serum sCD14 was conducted. The study group included 20 children who received standard "triple" eradication therapy for 7 days and 1 caps. of probiotic 3 times a day for 4 weeks, control group (20 children – who received only standard eradication therapy. It is shown that combined use of probiotics in the treatment of Helicobacter pylori infection enhances effectiveness of eradication of H.pylori. In the basis of action of probiotic strains of the drug is an anti-inflammatory effect mediated by the impact on non-specific mechanisms of innate immunity, provided by molecular mechanism responsible for induction of sCD14 synthesis.

Comparison of IL-6, IL-8 Concentrations in H. pylori- and non-H. pylori-associated Gastritis

Directory of Open Access Journals (Sweden)

Gontar Alamsyah Siregar

2014-12-01

Full Text Available BACKGROUND: Helicobacter pylori is a non-invasive microorganism causing intense gastric mucosal inflammatory and immune reaction. The gastric mucosal levels of the proinflammatory cytokines Interleukin 6 (IL-6 and IL-8 have been reported to be increased in H. pylori infection, but the serum levels in H. pylori infection is still controversial. The purpose of this study was to investigate the serum levels of IL-6 and IL-8 in H. pylori infection. METHODS: A cross sectional study was done on eighty consecutive gastritis patients admitted to endoscopy units at Adam Malik General Hospital and Permata Bunda Hospital, Medan, Indonesia from May-October 2014. Histopathology was performed for the diagnosis of gastritis. Rapid urease test for diagnosis of H. pylori infection. Serum samples were obtained to determine circulating IL-6 and IL-8. Univariate and bivariate analysis (independent t test were done. RESULTS: There were 41.25% patients infected with H. pylori. Circulatory IL-6 levels were significantly higher in H. pylori-infected patients compared to H. pylori negative, but there were no differences between serum levels of IL-8 in H. pylori positive and negative patients. CONCLUSIONS: The immune response to H. pylori promotes systemic inflammation, which was reflected in an increased level of serum IL-6. Serum levels of IL-8 were not significantly different between H. pylori positive and negative. KEYWORDS: Helicobacter pylori, gastritis, IL-6, IL-8, cytokine.

Helicobacter pylori-derived Heat shock protein 60 enhances angiogenesis via a CXCR2-mediated signaling pathway

Energy Technology Data Exchange (ETDEWEB)

Lin, Chen-Si [Department of Biological Science and Technology, National Chiao-Tung University, Hsin-Chu, Taiwan (China); School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan (China); He, Pei-Juin; Hsu, Wei-Tung [Department of Biological Science and Technology, National Chiao-Tung University, Hsin-Chu, Taiwan (China); Wu, Ming-Shiang [Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Wu, Chang-Jer [Department of Food Science, National Taiwan Ocean University, Keelung, Taiwan (China); Shen, Hsiao-Wei [Institute of Molecular Medicine and Bioengineering, National Chiao-Tung University, Hsin-Chu, Taiwan (China); Hwang, Chia-Hsiang [Yung-Shin Pharmaceutical Industry Co., Ltd., Tachia, Taichung, Taiwan (China); Lai, Yiu-Kay [Department of Life Science, Institute of Biotechnology, National Tsing Hua University, Hsin-Chu, Taiwan (China); Tsai, Nu-Man [School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan (China); Liao, Kuang-Wen, E-mail: kitchhen@yahoo.com.tw [Institute of Molecular Medicine and Bioengineering, National Chiao-Tung University, Hsin-Chu, Taiwan (China)

2010-06-25

Helicobacter pylori is a potent carcinogen associated with gastric cancer malignancy. Recently, H. pylori Heat shock protein 60 (HpHSP60) has been reported to promote cancer development by inducing chronic inflammation and promoting tumor cell migration. This study demonstrates a role for HpHSP60 in angiogenesis, a necessary precursor to tumor growth. We showed that HpHSP60 enhanced cell migration and tube formation, but not cell proliferation, in human umbilical vein endothelial cells (HUVECs). HpHSP60 also indirectly promoted HUVEC proliferation when HUVECs were co-cultured with supernatants collected from HpHSP60-treated AGS or THP-1 cells. The angiogenic array showed that HpHSP60 dramatically induced THP-1 cells and HUVECs to produce the chemotactic factors IL-8 and GRO. Inhibition of CXCR2, the receptor for IL-8 and GRO, or downstream PLC{beta}2/Ca2+-mediated signaling, significantly abolished HpHSP60-induced tube formation. In contrast, suppression of MAP K or PI3 K signaling did not affect HpHSP60-mediated tubulogenesis. These data suggest that HpHSP60 enhances angiogenesis via CXCR2/PLC{beta}2/Ca2+ signal transduction in endothelial cells.

Helicobacter pylori-derived Heat shock protein 60 enhances angiogenesis via a CXCR2-mediated signaling pathway

International Nuclear Information System (INIS)

Lin, Chen-Si; He, Pei-Juin; Hsu, Wei-Tung; Wu, Ming-Shiang; Wu, Chang-Jer; Shen, Hsiao-Wei; Hwang, Chia-Hsiang; Lai, Yiu-Kay; Tsai, Nu-Man; Liao, Kuang-Wen

2010-01-01

Helicobacter pylori is a potent carcinogen associated with gastric cancer malignancy. Recently, H. pylori Heat shock protein 60 (HpHSP60) has been reported to promote cancer development by inducing chronic inflammation and promoting tumor cell migration. This study demonstrates a role for HpHSP60 in angiogenesis, a necessary precursor to tumor growth. We showed that HpHSP60 enhanced cell migration and tube formation, but not cell proliferation, in human umbilical vein endothelial cells (HUVECs). HpHSP60 also indirectly promoted HUVEC proliferation when HUVECs were co-cultured with supernatants collected from HpHSP60-treated AGS or THP-1 cells. The angiogenic array showed that HpHSP60 dramatically induced THP-1 cells and HUVECs to produce the chemotactic factors IL-8 and GRO. Inhibition of CXCR2, the receptor for IL-8 and GRO, or downstream PLCβ2/Ca2+-mediated signaling, significantly abolished HpHSP60-induced tube formation. In contrast, suppression of MAP K or PI3 K signaling did not affect HpHSP60-mediated tubulogenesis. These data suggest that HpHSP60 enhances angiogenesis via CXCR2/PLCβ2/Ca2+ signal transduction in endothelial cells.

II Consenso Brasileiro sobre Helicobacter pylori Second Brazilian Consensus Conference on Helicobacter pylori infection

Directory of Open Access Journals (Sweden)

Luiz Gonzaga Vaz Coelho

2005-06-01

Full Text Available Avanços significativos ocorridos desde o Primeiro Consenso Brasileiro sobre H. pylori realizado em 1995, em Belo Horizonte, MG, justificam este segundo consenso. O evento foi organizado pela Federação Brasileira de Gastroenterologia e pelo Núcleo Brasileiro para Estudo do Helicobacter, sendo realizado em São Paulo nos dias 19 e 20 de junho de 2004. Contou com a participação das principais autoridades nacionais na área, a partir de lista elaborada pelas duas sociedades organizadoras do evento. Assim, participaram 36 delegados provenientes de 15 estados brasileiros, incluindo gastroenterologistas, patologistas, pediatras e microbiologistas. Os participantes foram alocados em um dos cinco sub-temas a serem contemplados no encontro, a saber: Helicobacter pylori e dispepsia funcional; Helicobacter pylori e AINEs; Helicobacter pylori e doença do refluxo gastroesofágico; tratamento Helicobacter pylori e retratamento Helicobacter pylori. Foi adotado como consensual as decisões que atingissem 70% ou mais de concordância entre os participantes. Os resultados foram apresentados em outubro de 2004 durante sessão especial da VI Semana Brasileira do Aparelho Digestivo, realizada em Recife, PE, e esta publicação apresenta o sumário das principais recomendações e conclusões do evento.Significant progress has been obtained since the First Brazilian Consensus Conference on H. pylori Infection held in 1995, in Belo Horizonte, MG, and justify a second meeting to establish updated guidelines on the current management of H. pylori infection. The Second Brazilian Consensus Conference on H. pylori Infection was organized by the Brazilian Federation of Gastroenterology and Brazilian Nucleus for the Study of Helicobacter and took place on June, 19-20, 2004 in São Paulo, SP. Thirty six delegates coming from 15 different Brazilian states including gastroenterologists, pathologists, microbiologists and pediatricians undertook the meeting. The

Diversification of the vacAs1m1 and vacAs2m2 strains of Helicobacter pylori in Meriones unguiculatus

Directory of Open Access Journals (Sweden)

Sandra Mendoza Elizalde

2016-11-01

Full Text Available The bacterium Helicobacter pylori exhibits great genetic diversity, and the pathogenic roles of its virulence factors have been widely studied. However, the evolutionary dynamics of H. pylori strains during stomach colonization are not well characterized. Here, we analyzed the microevolutionary dynamics of the toxigenic strain vacAs1m1, the non-toxigenic strain vacAs2m2, and a combination of both strains in an animal model over time. Meriones unguiculatus were inoculated with the following bacteria: group 1–toxigenic strain vacAs1m1/cagA+/cagE+/babA2+; ST181, group 2–non-toxigenic strain vacAs2m2/ cagA+/ cagE+/ babA2+; ST2901, and group 3–both strains. The gerbils were euthanized at different time points (3, 6, 12 and 18 months. In group 1, genetic alterations were observed at 6 and 12 months. With the combination of both strains, group 3 also exhibited genetic alterations at 3 and 18 months; moreover, a chimera, vacA m1-m2, was detected. Additionally, four new sequence types (STs were reported in the PubMLST database for H. pylori. Synonymous and non-synonymous mutations were analyzed and associated with alterations in amino acids. Microevolutionary analysis of the STs (PHYLOViZ identified in each group revealed many mutational changes in the toxigenic (vacAs1m1 and non-toxigenic (vacAs2m2 strains. Phylogenetic assessments (eBURST did not reveal clonal complexes. Our findings indicate that the toxigenic strain, vacAs1m1, and a combination of toxigenic and non-toxigenic strains acquired genetic material by recombination. The allelic combination, vacAs2m1, displayed the best adaptation in the animal model over time, and a chimera, m1-m2, was also identified, which confirmed previous reports.

Oxyntic gastric atrophy in Helicobacter pylori gastritis is distinct from autoimmune gastritis.

Science.gov (United States)

Venerito, Marino; Varbanova, Mariya; Röhl, Friedrich-Wilhelm; Reinhold, Dirk; Frauenschläger, Katrin; Jechorek, Doerthe; Weigt, Jochen; Link, Alexander; Malfertheiner, Peter

2016-08-01

To assess characteristics of oxyntic gastric atrophy (OGA) in autoimmune gastritis (AIG) compared with OGA as a consequence of Helicobacter pylori infection. Patients undergoing oesophagogastroduodenoscopy from July 2011 to October 2014 were prospectively included (N=452). Gastric biopsies were obtained for histology and H. pylori testing. Serum gastrin-17 (G17), pepsinogen (PG) I, PGII and antibodies against H. pylori and cytotoxin-associated gene A protein were determined in all patients. Antibodies against parietal cells and intrinsic factor were determined in patients with advanced (moderate to severe) OGA. Areas under the receiver operating characteristic curves (AUCs) were calculated for serum biomarkers and compared with histology. Overall, 34 patients (8.9%) had advanced OGA by histology (22 women, age 61±15 years). Current or past H. pylori infection and AIG were present in 14/34 and 22/34 patients, respectively. H. pylori-negative AIG patients (N=18) were more likely to have another autoimmune disease (OR 6.3; 95% CI 1.3 to 29.8), severe corpus atrophy (OR 10.1; 95% CI 1.9 to 54.1) and corpus intestinal metaplasia (OR 26.9; 95% CI 5.3 to 136.5) compared with H. pylori-positive patients with advanced OGA. Antrum atrophy was present in 39% of H. pylori-negative AIG patients. The diagnostic performance of G17, PG I and PGI/II was excellent for AIG patients (AUC=0.83, 0.95 and 0.97, respectively), but limited for H. pylori-positive patients with advanced OGA (AUC=0.62, 0.75 and 0.67, respectively). H. pylori-negative AIG has a distinct clinical, morphological and serological phenotype compared with advanced OGA in H. pylori gastritis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Metabolic consequences of Helicobacter pylori infection and eradication

Science.gov (United States)

Buzás, György Miklós

2014-01-01

Helicobacter pylori (H. pylori) is still the most prevalent infection of the world. Colonization of the stomach by this agent will invariably induce chronic gastritis which is a low-grade inflammatory state leading to local complications (peptic ulcer, gastric cancer, lymphoma) and remote manifestations. While H. pylori does not enter circulation, these extragastric manifestations are probably mediated by the cytokines and acute phase proteins produced by the inflammed mucosa. The epidemiologic link between the H. pylori infection and metabolic changes is inconstant and controversial. Growth delay was described mainly in low-income regions with high prevalence of the infection, where probably other nutritional and social factors contribute to it. The timely eradication of the infection will lead to a more healthy development of the young population, along with preventing peptic ulcers and gastric cancer An increase of total, low density lipoprotein and high density liporotein cholesterol levels in some infected people creates an atherogenic lipid profile which could promote atherosclerosis with its complications, myocardial infarction, stroke and peripheral vascular disease. Well designed and adequately powered long-term studies are required to see whether eradication of the infection will prevent these conditions. In case of glucose metabolism, the most consistent association was found between H. pylori and insulin resistance: again, proof that eradication prevents this common metabolic disturbance is expected. The results of eradication with standard regimens in diabetics are significantly worse than in non-diabetic patients, thus, more active regimens must be found to obtain better results. Successful eradication itself led to an increase of body mass index and cholesterol levels in some populations, while in others no such changes were encountered. Uncertainities of the metabolic consequences of H. pylori infection must be clarified in the future. PMID:24833852

Inactivation of Helicobacter pylori by Chloramination

Science.gov (United States)

Three strains of Helicobacter pylori (H. pylori) were studied to determine their resistance to chloramination. H. pylori is an organism listed on the U.S. Environmental Protection Agency’s (USEPA) Contaminant Control List (CCL). H. pylori was exposed to 2ppm of pre-formed monoc...

No Helicobacter pylori, no Helicobacter pylori-associated peptic ulcer disease

NARCIS (Netherlands)

Tytgat, G. N.

1995-01-01

Virtually all duodenal ulcers (DUs) and the vast majority of gastric ulcers (GUs) are the consequence of Helicobacter pylori-associated inflammation. In DUs, the inflammation is maximal in the antrum and is associated with gastric metaplasia in the bulb. Gastrin homeostasis is disturbed by H. pylori

Association of Vac A- and Cag A-specific Helicobacter pylori strain infection with spontaneous preterm birth.

Science.gov (United States)

Yang, Seung Woo; Kwon, Han Sung; Sohn, In Sook; Kim, Young Ju; Hwang, Han Sung

2017-04-01

To better understand the correlation between Helicobacter pylori (H. pylori) seropositivity and spontaneous preterm birth. A total of 320 pregnant women were classified into two groups: normal control singleton pregnant group (n = 264) and singleton spontaneous preterm birth group (n = 56). Blood samples were collected at the time of delivery, and the H. pylori IgG, various virulence factors and systemic inflammation status were compared between the two groups. Between the two groups, the serum H. pylori IgG, Cytotoxin-associated agntigen A (Cag A), Vacuolating cytotoxin A (Vac A) significantly increased in spontaneous preterm birth group than in the control group. Also, in preterm group, highly sensitive C-reactive protein (hsCRP) as a systemic inflammatory marker is statistically elevated at inflammatory status range. Whereas in the term pregnant group, hsCRP was normal range even though high incidence of H. pylori IgG seropositivity. Also, in the seropositive group, hsCRP is statistically correlated with H. pylori IgG, Cag A and Vac A. There is an association between the presence of antibodies against H. pylori in maternal serum and the development of preterm birth. Furthermore, serology type of H. pylori with Vac A, Cag A relates to preterm birth even though high H. pylori prevalence rate.

The effect of H. pylori eradication on meal-associated changes in plasma ghrelin and leptin

Directory of Open Access Journals (Sweden)

Chhada Aditi

2011-04-01

Full Text Available Abstract Background Appetite and energy expenditure are regulated in part by ghrelin and leptin produced in the gastric mucosa, which may be modified by H. pylori colonization. We prospectively evaluated the effect of H. pylori eradication on meal-associated changes in serum ghrelin and leptin levels, and body weight. Methods Veterans referred for upper GI endoscopy were evaluated at baseline and ≥8 weeks after endoscopy, and H. pylori status and body weight were ascertained. During the first visit in all subjects, and during subsequent visits in the initially H. pylori-positive subjects and controls, blood was collected after an overnight fast and 1 h after a standard high protein meal, and levels of eight hormones determined. Results Of 92 enrolled subjects, 38 were H. pylori-negative, 44 H. pylori-positive, and 10 were indeterminate. Among 23 H. pylori-positive subjects who completed evaluation after treatment, 21 were eradicated, and 2 failed eradication. After a median of seven months following eradication, six hormones related to energy homeostasis showed no significant differences, but post-prandial acylated ghrelin levels were nearly six-fold higher than pre-eradication (p = 0.005, and median integrated leptin levels also increased (20% significantly (p H. pylori-positive individuals, but was not significantly changed in those who were H. pylori-negative or indeterminant at baseline. Conclusions Circulating meal-associated leptin and ghrelin levels and BMI changed significantly after H. pylori eradication, providing direct evidence that H. pylori colonization is involved in ghrelin and leptin regulation, with consequent effects on body morphometry.

Halitosis and Helicobacter pylori infection

NARCIS (Netherlands)

Tangerman, A.; Winkel, E. G.; de Laat, L.; van Oijen, A. H.; de Boer, W. A.

There is disagreement about a possible relationship between Helicobacter pylori (H. pylori) infection and objective halitosis, as established by volatile sulfur compounds (VSCs) in the breath. Many studies related to H. pylori used self-reported halitosis, a subjective and unreliable method to

Helicobacter pylori in gastroduodenal perforation

Directory of Open Access Journals (Sweden)

Bharat B Dogra

2014-01-01

Full Text Available Background:peptic ulcers were earlier believed to be caused by dietary factors, gastric acid, and stress. However, in 1983, Warren and Marshall identified the correlation between Helicobacter pylori (H. pylori and peptic ulcers. It is now well established that most of the peptic ulcers occur as a result of H. pylori infection. But the co-relation between perforated peptic ulcer and H. pylori infection is not yet fully established. Aims and objectives : to study the prevalence of H. pylori infection in patients with perforated peptic ulcer. Materials and methods: this was a prospective study carried out in all cases of perforated peptic ulcer reporting in surgical wards of a medical college during 2008-2010. A total of 50 cases, presenting as acute perforation of duodenum and stomach during this period, formed the study group. After resuscitation, all the cases were subjected to emergency exploratory laparotomy. The exact site of perforation was identified, biopsy was taken from the ulcer margin from 2-3 sites and the tissue was sent for H. pylori culture and histopathological examination. Simple closure of perforation, omentoplasty, thorough peritoneal lavage and drainage was carried out. Results: out of the 50 cases of perforated peptic ulcer, 38 happened to be males, and only 12 were females. The age of the patients ranged from 20 to 70 years. All the patients underwent only emergency laparotomy. As many as 46 cases (92% turned out to be positive for H. pylori and only four cases (8% were negative for this infection. Postoperatively, patients who were found to be positive for H. pylori were put on anti-H. pylori treatment. Conclusion: there was a high prevalence of H. pylori infection in patients with perforated gastroduodenal ulcers.

Gastric mucosa-associated lymphoid tissue lymphomas and Helicobacter pylori infection: A Colombian perspective

Institute of Scientific and Technical Information of China (English)

Sally Yepes; Maria Mercedes Torres; Carlos Saavedra; Rafael Andrade

2012-01-01

AIM:To assess the significance of chromosome translocation t(11;18)(q21;q21),B-cell lymphoma 10 (BCL-10)protein and Helicobacter pylori (H.pylori) infection in gastric mucosa-associated lymphoid tissue (MALT) lymphoma in Colombia.METHODS:Fifty cases of gastric MALT lymphoma and their respective post-treatment follow-up biopsies were examined to assess the presence of the translocation t(11;18)(q21;q21) as identified by fluorescence in situ hybridization; to detect protein expression patterns of BCL10 using immunohistochemistry; and for evaluation of tumor histology to determine the correlation of these factors and resistance to H.pylori eradication.RESULTS:Infection with H.pylori was confirmed in all cases of gastric MALT lymphoma in association with chronic gastritis.Bacterial eradication led to tumor regression in 66％ of cases.The translocation t(11;18)(q21;q21) was not present in any of these cases,nor was there evidence of tumor transformation to diffuse large B-cell lymphoma.Thirty-four percent of the patients showed resistance to tumor regression,and within this group,7 cases,representing 14％ of all those analyzed,were considered to be t(11;18)(q21;q21)-positive gastric MALT lymphomas.Protein expression of BCL10 in the nucleus was associated with the presence of translocation and treatment resistance.Cases that were considered unresponsive to therapy were histologically characterized by the presence of homogeneous tumor cells and a lack of plasmacytic differentiation.Responder cases exhibited higher cellular heterogeneity and a greater frequency of plasma cells.CONCLUSION:Both t(11;18)(q21;q21)-positive MALT lymphoma cases and those with nuclear BCL10 expression are considered resistant to H,pylori eradication.It is suggested that chronic antigenic stimulation is not a dominant event in resistant cases.

Nutrition and Helicobacter pylori: Host Diet and Nutritional Immunity Influence Bacterial Virulence and Disease Outcome

Directory of Open Access Journals (Sweden)

Kathryn P. Haley

2016-01-01

Full Text Available Helicobacter pylori colonizes the stomachs of greater than 50% of the world’s human population making it arguably one of the most successful bacterial pathogens. Chronic H. pylori colonization results in gastritis in nearly all patients; however in a subset of people, persistent infection with H. pylori is associated with an increased risk for more severe disease outcomes including B-cell lymphoma of mucosal-associated lymphoid tissue (MALT lymphoma and invasive adenocarcinoma. Research aimed at elucidating determinants that mediate disease progression has revealed genetic differences in both humans and H. pylori which increase the risk for developing gastric cancer. Furthermore, host diet and nutrition status have been shown to influence H. pylori-associated disease outcomes. In this review we will discuss how H. pylori is able to create a replicative niche within the hostile host environment by subverting and modifying the host-generated immune response as well as successfully competing for limited nutrients such as transition metals by deploying an arsenal of metal acquisition proteins and virulence factors. Lastly, we will discuss how micronutrient availability or alterations in the gastric microbiome may exacerbate negative disease outcomes associated with H. pylori colonization.

An engineered Lactococcus lactis strain exerts significant immune responses through efficient expression and delivery of Helicobacter pylori Lpp20 antigen.

Science.gov (United States)

Zhang, Rongguang; Peng, Xiaoyan; Duan, Guangcai; Shi, Qingfeng; Chen, Shuaiyin; Wang, Chen; Fan, Qingtang; Xi, Yuanlin

2016-12-01

To produce and deliver Helicobacter pylori lipoprotein Lpp20 via using Lactococcus lactis with aim of developing an efficient way to use this protective antigen in vaccine formulation. An engineered L. lactis strain carrying the lpp20 gene from H. pylori was constructed. The inducible expression of Lpp20 in L. lactis was detected as a 20 kDa intracellular protein by SDS-PAGE. Lpp20 constituted 10 % of the L. lactis cellular proteins. The expression product was highly immunoreactive, as demonstrated by western blot assays using mouse anti-H. pylori sera. Animal experimentation showed that oral vaccination with the engineered strain excited significantly elevated levels of serum Lpp20-specific IgG antibodies in BALB/c mice (P lactis, demonstrating an efficient utilization mode of Lpp20 in anti-H. pylori vaccination.

Helicobacter pylori and non-malignant diseases.

Science.gov (United States)

Matysiak-Budnik, Tamara; Laszewicz, Wiktor; Lamarque, Dominique; Chaussade, Stanislas

2006-10-01

The prevalence of Helicobacter pylori-associated peptic ulcers, in particular duodenal ulcers, is decreasing following decreasing prevalence of H. pylori infection, while the frequency of non-steroidal anti-inflammatory drugs (NSAIDs)-induced and H. pylori-negative idiopathic ulcers is increasing. The incidence of bleeding ulcers has been stable during the last decades. Several putative H. pylori virulence genes, i.e., cag, vacA, babA, or dupA, as well as host-related genetic factors like IL-1beta and TNFalpha-gene polymorphism, have been proposed as risk factors for duodenal ulcer. H. pylori eradication may prevent NSAID complications, in particular, when it is performed before introduction of NSAIDs. There is a complex association between H. pylori and gastroesophageal reflux disease (GERD), and the impact of H. pylori eradication on the appearance of GERD symptoms depends on various host- and bacteria-related factors. Eradication of H. pylori in GERD is recommended in patients before instauration of a long-term PPI treatment to prevent the development of gastric atrophy. A small proportion (10%) of non-ulcer dyspepsia cases may be attributed to H. pylori and may benefit from eradication treatment. A test-and-treat strategy is more cost-effective than prompt endoscopy in the initial management of dyspepsia.

3rd Brazilian consensus on Helicobacter pylori 3º Consenso Brasileiro para Estudo do Helicobacter pylori

Directory of Open Access Journals (Sweden)

Luiz Gonzaga Coelho

Full Text Available Significant progress has been obtained since the Second Brazilian Consensus Conference on Helicobacter pylori Infection held in 2004, in São Paulo, SP, Brazil, and justify a third meeting to establish updated guidelines on the current management of H. pylori infection. The Third Brazilian Consensus Conference on H pylori Infection was organized by the Brazilian Nucleus for the Study of Helicobacter, a Department of the Brazilian Federation of Gastroenterology and took place on April 12-15, 2011, in Bento Gonçalves, RS, Brazil. Thirty-one delegates coming from the five Brazilian regions and one international guest, including gastroenterologists, pathologists, epidemiologists, and pediatricians undertook the meeting. The participants were allocated in one of the five main topics of the meeting: H pylori, functional dyspepsia and diagnosis; H pylori and gastric cancer; H pylori and other associated disorders; H pylori treatment and retreatment; and, epidemiology of H pylori infection in Brazil. The results of each subgroup were submitted to a final consensus voting to all participants. Relevant data were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded. Seventy per cent and more votes were considered as acceptance for the final statement. This article presents the main recommendations and conclusions to guide Brazilian doctors involved in the management of H pylori infection.Os avanços significativos ocorridos desde o Segundo Consenso Brasileiro sobre H. pylori realizado em 2004, em São Paulo, justificam este terceiro consenso. O evento foi organizado pelo Núcleo Brasileiro para Estudo do Helicobacter, departamento da Federação Brasileira de Gastroenterologia, tendo sido realizado em Bento Gonçalves, RS, nos dias 12 a 15 de abril de 2011. Contou com a participação de 30 delegados provenientes das cinco regiões brasileiras e um convidado internacional, incluindo gastroenterologistas

A thin-layer liquid culture technique for the growth of Helicobacter pylori.

Science.gov (United States)

Joo, Jung-Soo; Park, Kyung-Chul; Song, Jae-Young; Kim, Dong-Hyun; Lee, Kyung-Ja; Kwon, Young-Cheol; Kim, Jung-Min; Kim, Kyung-Mi; Youn, Hee-Shang; Kang, Hyung-Lyun; Baik, Seung-Chul; Lee, Woo-Kon; Cho, Myung-Je; Rhee, Kwang-Ho

2010-08-01

Several attempts have been successful in liquid cultivation of Helicobaccter pylori. However, there is a need to improve the growth of H. pylori in liquid media in order to get affluent growth and a simple approach for examining bacterial properties. We introduce here a thin-layer liquid culture technique for the growth of H. pylori. A thin-layer liquid culture system was established by adding liquid media to a 90-mm diameter Petri dish. Optimal conditions for bacterial growth were investigated and then viability, growth curve, and released proteins were examined. Maximal growth of H. pylori was obtained by adding 3 mL of brucella broth supplemented with 10% horse to a Petri dish. H. pylori grew in both DMEM and RPMI-1640 supplemented with 10% fetal bovine serum and 0.5% yeast extract. Serum-free RPMI-1640 supported the growth of H. pylori when supplemented with dimethyl-beta-cyclodextrin (200 microg/mL) and 1% yeast extract. Under optimal growth, H. pylori grew exponentially for 28 hours, reaching a density of 3.4 OD(600) with a generation time of 3.3 hours. After 24 hours, cultures at a cell density of 1.0 OD(600) contained 1.3 +/- 0.1 x 10(9 )CFU/mL. gamma-Glutamyl transpeptidase, nuclease, superoxide dismutase, and urease were not detected in culture supernatants at 24 hours in thin-layer liquid culture, but were present at 48 hours, whereas alcohol dehydrogenase, alkylhydroperoxide reductase, catalase, and vacuolating cytotoxin were detected at 24 hours. Thin-layer liquid culture technique is feasible, and can serve as a versatile liquid culture technique for investigating bacterial properties of H. pylori.

Helicobacter pylori infection and nonmalignant diseases.

Science.gov (United States)

Sjomina, Olga; Heluwaert, Frederic; Moussata, Driffa; Leja, Marcis

2017-09-01

A substantial decrease in Helicobacter pylori-associated peptic ulcer disease has been observed during the last decades. Drug-related ulcers as well as idiopathic ulcers are becoming predominant and are more refractory to treatment; however, H. pylori infection still plays an important role in ulcer bleeding and recurrence after therapy. The effect of H. pylori eradication upon functional dyspepsia symptoms has been reviewed in this article and generally confirms the results of previous meta-analyses. Additional evidence suggests a lack of impact upon the quality of life, in spite of improvement in symptoms. The association of H. pylori with gastroesophageal reflux disease and Barrett's esophagus remains controversial with a majority of published studies showing a negative association. Furthermore, a strong inverse relationship between the presence of H. pylori and the esophageal eosinophilia was also reported. Several studies and a review addressed the role of H. pylori in autoimmune gastritis and pernicious anemia. The association of the above still remains controversial. Finally, the necessity of routine endoscopy and H. pylori eradication before bariatric surgery is discussed. Several studies suggest the rationale of preoperative upper endoscopy and H. pylori eradication prior to surgery. However, the prevalence of H. pylori infection prior to surgery in these studies generally reflects the overall prevalence of the infection in the particular geographic area. In addition, results on the role of H. pylori in developing postoperative complications remain controversial. © 2017 John Wiley & Sons Ltd.

Helicobacter pylori infection in children.

Science.gov (United States)

Kalach, Nicolas; Bontems, Patrick; Raymond, Josette

2017-09-01

Helicobacter pylori infection in children differs from that in adults, from the point of view of epidemiology, host response, clinical features, related diseases, and diagnosis, as well as treatment strategies. The prevalence of H. pylori infection, in both children and adults, is decreasing in the Western World as well as in some developing countries, which contrasts with the increase in childhood asthma and allergic diseases. Recurrent abdominal pain is not specific during H. pylori infection in children. The role of H. pylori infection and failure to thrive, children's growth, type I diabetes mellitus (T1DM) and celiac disease remains controversial. The main initial diagnosis is based on upper digestive endoscopy with biopsy-based methods. Nodular gastritis may be a pathognomonic endoscopic finding of childhood H. pylori infection. The infection eradication control is based on validated noninvasive tests. The main cause of treatment failure of H. pylori infection is its clarithromycin resistance. We recommend standard antibiotic susceptibility testing of H. pylori in pediatric patients prior to the initiation of eradication therapy. H. pylori treatment in children should be based on an evaluation of the rate of eradication in the local population, a systematic use of a treatment adapted to the susceptibility profile and a treatment compliance greater than 90%. The last meta-analysis in children did not show an advantage for sequential therapy when compared to a 14-day triple therapy. Finally, the high rate of antibiotic resistance responsible for therapy failure in recent years justifies the necessity of a novel vaccine to prevent H. pylori infection in children. © 2017 John Wiley & Sons Ltd.

Low-density Lipoprotein Receptor-related Protein-1 (LRP1) Mediates Autophagy and Apoptosis Caused by Helicobacter pylori VacA*

OpenAIRE

Yahiro, Kinnosuke; Satoh, Mamoru; Nakano, Masayuki; Hisatsune, Junzo; Isomoto, Hajime; Sap, Jan; Suzuki, Hidekazu; Nomura, Fumio; Noda, Masatoshi; Moss, Joel; Hirayama, Toshiya

2012-01-01

In Helicobacter pylori infection, vacuolating cytotoxin (VacA)-induced mitochondrial damage leading to apoptosis is believed to be a major cause of cell death. It has also been proposed that VacA-induced autophagy serves as a host mechanism to limit toxin-induced cellular damage. Apoptosis and autophagy are two dynamic and opposing processes that must be balanced to regulate cell death and survival. Here we identify the low-density lipoprotein receptor-related protein-1 (LRP1) as the VacA rec...

Study of Cyclooxygenase-2 Expression in Sprague Dawley Rat Gastric Cancer Induced by H. Pylori

Directory of Open Access Journals (Sweden)

Pooladi A

2011-01-01

Full Text Available Background and Objectives: Gastric cancer is one of the most common gastrointestinal tumors; the incidence and mortality of gastric cancer are on the increase nowadays. Helicobacter pylori(H.Pylori causes chronic active gastritis and peptic ulcer disease. Cycloocygenase-2 (COX-2 is the central enzyme in the biosynthetic pathway to prostaglandins. Studies from different laboratories suggested that over-expression of COX-2 was detected in colon and other tumors. To obtain direct evidence concerning this relationship, we investigated the immunohistochemical findings of gastric mucosa using an animal model of gastric cancer induced by H. pylori in sprague dawley rat.Methods: The rats were randomly assigned into three groups(n=5. Those of experimental group2 were given MNU. one week after completion of MNU administration, rats in experimental groups 1 were inoculated with H. pylori three times every other day. Rats in control group(group 3 received neither MNU nor H. pylori. Rats of groups 1, 2, and control group were maintained on standard diets throughout the experiment. Rat were weighed and sacrificed under anesthesia with ether at 20 weeks after infection. One half of the excised stomachs, were fixed in neutral-buffered 10% formalin and were cut into approximately six strips, which were processed by standard methods, embedded in paraffin, sectioned at 6 µm, and stained with hematoxylin and eosin (H&E and immunohistochemistry for Cox-2 protein detection. To confirm H. pylori infection, samples ( 3-mm2 of stomach mucosa transferred to appropriate medium and Colonies were identified by characteristic Gram’s stain morphology, and by urease, catalase, and oxidase activity sample was also placed into the gel of a rapid urease test kit.Results: Data showed a significant decrease of animal body weight in experimental groups compared with control group. Histopathological studies showed severe infiltration of the lamina propria and submucusaal layer by

The effect of H. pylori eradication on meal-associated changes in plasma ghrelin and leptin.

Science.gov (United States)

Francois, Fritz; Roper, Jatin; Joseph, Neal; Pei, Zhiheng; Chhada, Aditi; Shak, Joshua R; de Perez, Asalia Z Olivares; Perez-Perez, Guillermo I; Blaser, Martin J

2011-04-14

Appetite and energy expenditure are regulated in part by ghrelin and leptin produced in the gastric mucosa, which may be modified by H. pylori colonization. We prospectively evaluated the effect of H. pylori eradication on meal-associated changes in serum ghrelin and leptin levels, and body weight. Veterans referred for upper GI endoscopy were evaluated at baseline and ≥8 weeks after endoscopy, and H. pylori status and body weight were ascertained. During the first visit in all subjects, and during subsequent visits in the initially H. pylori-positive subjects and controls, blood was collected after an overnight fast and 1 h after a standard high protein meal, and levels of eight hormones determined. Of 92 enrolled subjects, 38 were H. pylori-negative, 44 H. pylori-positive, and 10 were indeterminate. Among 23 H. pylori-positive subjects who completed evaluation after treatment, 21 were eradicated, and 2 failed eradication. After a median of seven months following eradication, six hormones related to energy homeostasis showed no significant differences, but post-prandial acylated ghrelin levels were nearly six-fold higher than pre-eradication (p=0.005), and median integrated leptin levels also increased (20%) significantly (p<0.001). BMI significantly increased (5 ± 2%; p=0.008) over 18 months in the initially H. pylori-positive individuals, but was not significantly changed in those who were H. pylori-negative or indeterminant at baseline. Circulating meal-associated leptin and ghrelin levels and BMI changed significantly after H. pylori eradication, providing direct evidence that H. pylori colonization is involved in ghrelin and leptin regulation, with consequent effects on body morphometry. © 2011 Francois et al; licensee BioMed Central Ltd.

Detection of Helicobacter pylori urease antigen in saliva in patients with different gastric H. pylori status.

Science.gov (United States)

El Khadir, Mounia; Alaoui Boukhris, Samia; Benajah, Dafr-Allah; El Rhazi, Karima; Ibrahimi, Sidi Adil; El Abkari, Mohamed; Harmouch, Taoufiq; Nejjari, Chakib; Mahmoud, Mustapha; Benlemlih, Mohamed; Bennani, Bahia

2016-07-01

Finding a simple, accurate, and noninvasive diagnosis method is a substantial challenge for the detection of Helicobacter pylori. The aim of the present study was to compare the presence of H. pylori urease antigen in saliva with the presence of this bacterium in gastric mucosa. Saliva samples and gastric biopsies were taken from 153 consenting Moroccan patients. Saliva samples were analyzed using an immunochromatographic test for urease antigen H. pylori detection. Thereafter, the gastric biopsies were analyzed by histology and polymerase chain reaction (PCR) to detect this bacterium. From a total of 153 recruited Moroccan patients, H. pylori was detected in 28 (18.30%), 87 (57.24%), and 69 (45.10%) cases by saliva test, histology, and PCR, respectively. A significant association was observed between the presence of H. pylori antigen in saliva and age. However, no association was found with sex, H. pylori virulence factors, gastric disease outcome, and density of the bacterium on the gastric mucosa. Considering that only 90 patients presented concordant results on H. pylori diagnosis (positive or negative) by both histology and PCR, the immunochromatographic test showed very low sensitivity (29.79%) and high specificity (90.70%). Of these two tests, the positive and negative predictive values were 77.78% and 54.17%, respectively. The accuracy of the test for salivary detection of urease antigen H. pylori was 58.89%. This study demonstrated a low detection rate of H. pylori antigens in saliva compared with the presence of this bacterium in gastric mucosa, suggesting that saliva cannot be used as a suitable sample for the diagnosis of H. pylori in our study population. Copyright © 2016. Published by Elsevier Taiwan LLC.

Clinical Manifestations of Helicobacter pylori-Negative Gastritis.

Science.gov (United States)

Shiota, Seiji; Thrift, Aaron P; Green, Linda; Shah, Rajesh; Verstovsek, Gordana; Rugge, Massimo; Graham, David Y; El-Serag, Hashem B

2017-07-01

There are data to suggest the existence of non-Helicobacter pylori gastritis. However, the risk factors and clinical course for H pylori-negative gastritis remain unclear. We aimed to examine the prevalence and determinants of H pylori-negative gastritis in a large multiethnic clinical population. We conducted a cross-sectional study among patents scheduled for an elective esophagastroduodenoscopy or attending selected primary care clinics and eligible for screening colonoscopy at a single Veterans Affairs medical center. We identified cases of H pylor-negative gastritis, H pylori-positive gastritis, and H pylori-negative nongastritis, where gastritis was defined by the presence of neutrophils and/or mononuclear cells. Risk factors for H pylori-negative gastritis were analyzed in logistic regression models. A total of 1240 patients had information from all biopsy sites, of whom 695 (56.0%) had gastritis. H pylori-negative gastritis was present in 123 patients (9.9% of all study subjects and 17.7% of all patients with gastritis). Among all patients with gastritis, African Americans were statistically significantly less likely than non-Hispanic whites to have H pylori-negative gastritis (odds ratio, 0.25; 95% confidence interval, 0.14-0.43). Conversely, PPI users were more likely to have H pylori-negative gastritis than H pylori-positive gastritis compared with nonusers (odds ratio, 2.02; 95% confidence interval, 1.17-3.49). The cumulative incidence of gastric erosions and ulcers were higher in patients with H pylori-negative gastritis than H pylori-negative nongastritis. We found that H pylori-negative gastritis was present in approximately 18% of patients with gastritis. The potential for H pylori-negative gastritis to progress or the risk of gastric cancer of those with gastric mucosal atrophy/intestinal metaplasia remains unclear. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Isocitrate dehydrogenase of Helicobacter pylori potentially induces humoral immune response in subjects with peptic ulcer disease and gastritis.

Directory of Open Access Journals (Sweden)

M Abid Hussain

Full Text Available BACKGROUND: H. pylori causes gastritis and peptic ulcers and is a risk factor for the development of gastric carcinoma. Many of the proteins such as urease, porins, flagellins and toxins such as lipo-polysaccharides have been identified as potential virulence factors which induce proinflammatory reaction. We report immunogenic potentials of isocitrate dehydrogenase (ICD, an important house keeping protein of H. pylori. METHODOLOGY/PRINCIPAL FINDINGS: Amino acid sequences of H. pylori ICD were subjected to in silico analysis for regions with predictably high antigenic indexes. Also, computational modelling of the H. pylori ICD as juxtaposed to the E. coli ICD was carried out to determine levels of structure similarity and the availability of surface exposed motifs, if any. The icd gene was cloned, expressed and purified to a very high homogeneity. Humoral response directed against H. pylori ICD was detected through an enzyme linked immunosorbent assay (ELISA in 82 human subjects comprising of 58 patients with H. pylori associated gastritis or ulcer disease and 24 asymptomatic healthy controls. The H. pylori ICD elicited potentially high humoral immune response and revealed high antibody titers in sera corresponding to endoscopically-confirmed gastritis and ulcer disease subjects. However, urea-breath-test negative healthy control samples and asymptomatic control samples did not reveal any detectable immune responses. The ELISA for proinflammatory cytokine IL-8 did not exhibit any significant proinflammatory activity of ICD. CONCLUSIONS/SIGNIFICANCE: ICD of H. pylori is an immunogen which interacts with the host immune system subsequent to a possible autolytic-release and thereby significantly elicits humoral responses in individuals with invasive H. pylori infection. However, ICD could not significantly stimulate IL8 induction in a cultured macrophage cell line (THP1 and therefore, may not be a notable proinflammatory agent.

Helicobacter pylori and non-malignant diseases.

Science.gov (United States)

Furuta, Takahisa; Delchier, Jean-Charles

2009-09-01

It is well known that Helicobacter pylori infection is associated with many nonmalignant disorders such as gastritis, peptic ulcer, gastroesophageal reflux disease (GERD), gastric polyp, nonsteroidal anti-inflammatory drug (NSAID)/aspirin-induced gastric injury, and functional dyspepsia. In 2008, interesting articles on the association of H. pylori infection with these disorders were presented, some of which intended to reveal the mechanisms of inter-individual differences in response to H. pylori infection, and have demonstrated that genetic differences in host and bacterial factors as well as environmental factors account for these differences. A decline in the occurrence of peptic ulcer related to H. pylori was confirmed. An inverse relationship between H. pylori infection and GERD was also confirmed but the impact of gastric atrophy on the prevention of GERD remained debatable. For NSAID-induced gastric injury, eradication of H. pylori infection has been recommended. During this year, eradication of H. pylori infection was recommended for patients treated with antiplatelet therapy as well as aspirin and NSAID. It was also reported that for patients with functional dyspepsia, eradication of H. pylori offers a modest but significant benefit.

Mucosal Progranulin expression is induced by H. pylori, but independent of Secretory Leukocyte Protease Inhibitor (SLPI expression

Directory of Open Access Journals (Sweden)

Treiber Gerhard

2011-05-01

Full Text Available Abstract Background Mucosal levels of Secretory Leukocyte Protease Inhibitor (SLPI are specifically reduced in relation to H. pylori-induced gastritis. Progranulin is an epithelial growth factor that is proteolytically degraded into fragments by elastase (the main target of SLPI. Considering the role of SLPI for regulating the activity of elastase, we studied whether the H. pylori-induced reduction of SLPI and the resulting increase of elastase-derived activity would reduce the Progranulin protein levels both ex vivo and in vitro. Methods The expression of Progranulin was studied in biopsies of H. pylori-positive, -negative and -eradicated subjects as well as in the gastric tumor cell line AGS by ELISA, immunohistochemistry and real-time RT-PCR. Results H. pylori-infected subjects had about 2-fold increased antral Progranulin expression compared to H. pylori-negative and -eradicated subjects (P H. pylori infection; both epithelial and infiltrating immune cells contributed to the higher Progranulin expression levels. The H. pylori-induced upregulation of Progranulin was verified in AGS cells infected by H. pylori. The down-regulation of endogenous SLPI expression in AGS cells by siRNA methodology did not affect the Progranulin expression independent of the infection by H. pylori. Conclusions Taken together, Progranulin was identified as novel molecule that is upregulated in context to H. pylori infection. In contrast to other diseases, SLPI seems not to have a regulatory role for Progranulin in H. pylori-mediated gastritis.

Mucosal Progranulin expression is induced by H. pylori, but independent of Secretory Leukocyte Protease Inhibitor (SLPI) expression.

Science.gov (United States)

Wex, Thomas; Kuester, Doerthe; Schönberg, Cornelius; Schindele, Daniel; Treiber, Gerhard; Malfertheiner, Peter

2011-05-26

Mucosal levels of Secretory Leukocyte Protease Inhibitor (SLPI) are specifically reduced in relation to H. pylori-induced gastritis. Progranulin is an epithelial growth factor that is proteolytically degraded into fragments by elastase (the main target of SLPI). Considering the role of SLPI for regulating the activity of elastase, we studied whether the H. pylori-induced reduction of SLPI and the resulting increase of elastase-derived activity would reduce the Progranulin protein levels both ex vivo and in vitro. The expression of Progranulin was studied in biopsies of H. pylori-positive, -negative and -eradicated subjects as well as in the gastric tumor cell line AGS by ELISA, immunohistochemistry and real-time RT-PCR. H. pylori-infected subjects had about 2-fold increased antral Progranulin expression compared to H. pylori-negative and -eradicated subjects (P Progranulin and SLPI levels were identified. Immunohistochemical analysis confirmed the upregulation of Progranulin in relation to H. pylori infection; both epithelial and infiltrating immune cells contributed to the higher Progranulin expression levels. The H. pylori-induced upregulation of Progranulin was verified in AGS cells infected by H. pylori. The down-regulation of endogenous SLPI expression in AGS cells by siRNA methodology did not affect the Progranulin expression independent of the infection by H. pylori. Taken together, Progranulin was identified as novel molecule that is upregulated in context to H. pylori infection. In contrast to other diseases, SLPI seems not to have a regulatory role for Progranulin in H. pylori-mediated gastritis.

The HP0256 gene product is involved in motility and cell envelope architecture of Helicobacter pylori

LENUS (Irish Health Repository)

Douillard, Francois P

2010-04-08

Abstract Background Helicobacter pylori is the causative agent for gastritis, and peptic and duodenal ulcers. The bacterium displays 5-6 polar sheathed flagella that are essential for colonisation and persistence in the gastric mucosa. The biochemistry and genetics of flagellar biogenesis in H. pylori has not been fully elucidated. Bioinformatics analysis suggested that the gene HP0256, annotated as hypothetical, was a FliJ homologue. In Salmonella, FliJ is a chaperone escort protein for FlgN and FliT, two proteins that themselves display chaperone activity for components of the hook, the rod and the filament. Results Ablation of the HP0256 gene in H. pylori significantly reduced motility. However, flagellin and hook protein synthesis was not affected in the HP0256 mutant. Transmission electron transmission microscopy revealed that the HP0256 mutant cells displayed a normal flagellum configuration, suggesting that HP0256 was not essential for assembly and polar localisation of the flagella in the cell. Interestingly, whole genome microarrays of an HP0256 mutant revealed transcriptional changes in a number of genes associated with the flagellar regulon and the cell envelope, such as outer membrane proteins and adhesins. Consistent with the array data, lack of the HP0256 gene significantly reduced adhesion and the inflammatory response in host cells. Conclusions We conclude that HP0256 is not a functional counterpart of FliJ in H. pylori. However, it is required for full motility and it is involved, possibly indirectly, in expression of outer membrane proteins and adhesins involved in pathogenesis and adhesion.

Impact of Anti-Helicobacter Therapy of H.pylori-Infected Parents on H.pylori Reinfection Rate in Children after Successful Eradication

Directory of Open Access Journals (Sweden)

O.P. Volosovets

2012-02-01

Full Text Available The article presents the data about the rate of H.pylori reinfection during 12 months after anti-helicobacter therapy among the children after successful eradication. It was shown that H.pylori reinfection rate was lower in children after successful eradication who were living after the treatment with parents non-infectead with H.pylori than among children who were living with H.pylori-infected parents. It was demonstrated that simultaneous anti-helicobacter therapy in H.pylori-infected parents of children with with chronic gastroduodenal diseases associated with H.pylori decreased H.pylori reinfection rate in children with successful eradication.

Autophagy-related genes in Helicobacter pylori infection.

Science.gov (United States)

Tanaka, Shingo; Nagashima, Hiroyuki; Uotani, Takahiro; Graham, David Y; Yamaoka, Yoshio

2017-06-01

In vitro studies have shown that Helicobacter pylori (H. pylori) infection induces autophagy in gastric epithelial cells. However, prolonged exposure to H. pylori reduces autophagy by preventing maturation of the autolysosome. The alterations of the autophagy-related genes in H. pylori infection are not yet fully understood. We analyzed autophagy-related gene expression in H. pylori-infected gastric mucosa compared with uninfected gastric mucosa obtained from 136 Bhutanese volunteers with mild dyspeptic symptoms. We also studied single nucleotide polymorphisms (SNPs) of autophagy-related gene in 283 Bhutanese participants to identify the influence on susceptibility to H. pylori infection. Microarray analysis of 226 autophagy-related genes showed that 16 genes were upregulated (7%) and nine were downregulated (4%). We used quantitative reverse transcriptase polymerase chain reaction to measure mRNA levels of the downregulated genes (ATG16L1, ATG5, ATG4D, and ATG9A) that were core molecules of autophagy. ATG16L1 and ATG5 mRNA levels in H. pylori-positive specimens (n=86) were significantly less than those in H. pylori-negative specimens (n=50). ATG16L1 mRNA levels were inversely related to H. pylori density. We also compared SNPs of ATG16L1 (rs2241880) among 206 H. pylori-positive and 77 H. pylori-negative subjects. The odds ratio for the presence of H. pylori in the GG genotype was 0.40 (95% CI: 0.18-0.91) relative to the AA/AG genotypes. Autophagy-related gene expression profiling using high-throughput microarray analysis indicated that downregulation of core autophagy machinery genes may depress autophagy functions and possibly provide a better intracellular habit for H. pylori in gastric epithelial cells. © 2017 John Wiley & Sons Ltd.

Helicobacter Pylori Seropostivity of Colon Cancer

Directory of Open Access Journals (Sweden)

F. Tugba Kos

2014-03-01

Full Text Available Aim: Until now many researches have showed that Helicobacter pylori infection may be etiological factor of colorectal cancer. The aim of current study was to investigate the frequency of H.pylori infection seropositivity of colorectal cancer patients and compare the clinicopathological features of H.pylori positive patients with negative ones. Material and Method: Seventy four colorectal patients were included in study. Retrospectively, patients clinical features, surgery history and pathological characteristics were screened. Patients group serum samples were collected. H.pylori Ig G level were quantitatively measured with ELISA method and levels above 5 arbU/ml were accepted as seropositive. Results: Patients median age was 60.5 ( range 26-83 and 56.8% (n=42 were male. H.pylori Ig G was positive in 37.8% (n=28 and negative in 62.2% (n=46 of patient group. H.pylori serpositive and negative patients median age of diagnosis were 56 and 64 respectively (p=0.01. There were no significant difference between H.pylori seropositive group when compared with negative group according to age, level of CEA and Ca 19-9, stage, lymph node involvement, perineural and vascular invasion, presence of polyps, differantion, localisation of tumours. Discussion: H.pylori seropositive patients were diagnosed at younger age. Association of this finding with etiology was confusing. Further studies with healthy controls may provide detailed information about whether H.pylori seropositivity is associated with colorectal cancer etiology.

Dynamic HypA zinc site is essential for acid viability and proper urease maturation in Helicobacter pylori.

Science.gov (United States)

Johnson, Ryan C; Hu, Heidi Q; Merrell, D Scott; Maroney, Michael J

2015-04-01

Helicobacter pylori requires urease activity in order to survive in the acid environment of the human stomach. Urease is regulated in part by nickelation, a process that requires the HypA protein, which is a putative nickel metallochaperone that is generally associated with hydrogenase maturation. However, in H. pylori, HypA plays a dual role. In addition to an N-terminal nickel binding site, HypA proteins also contain a structural zinc site that is coordinated by two rigorously conserved CXXC sequences, which in H. pylori are flanked by His residues. These structural Zn sites are known to be dynamic, converting from Zn(Cys)4 centers at pH 7.2 to Zn(Cys)2(His)2 centers at pH 6.3 in the presence of Ni(ii) ions. In this study, mutant strains of H. pylori that express zinc site variants of the HypA protein are used to show that the structural changes in the zinc site are important for the acid viability of the bacterium, and that a reduction in acid viability in these variants can be traced in large measure to deficient urease activity. This in turn leads to a model that connects the Zn(Cys)4 coordination to urease maturation.

Maintenance of the cell morphology by MinC in Helicobacter pylori.

Directory of Open Access Journals (Sweden)

Pei-Yu Chiou

Full Text Available In the model organism Escherichia coli, Min proteins are involved in regulating the division of septa formation. The computational genome analysis of Helicobacter pylori, a gram-negative microaerophilic bacterium causing gastritis and peptic ulceration, also identified MinC, MinD, and MinE. However, MinC (HP1053 shares a low identity with those of other bacteria and its function in H. pylori remains unclear. In this study, we used morphological and genetic approaches to examine the molecular role of MinC. The results were shown that an H. pylori mutant lacking MinC forms filamentous cells, while the wild-type strain retains the shape of short rods. In addition, a minC mutant regains the short rods when complemented with an intact minCHp gene. The overexpression of MinCHp in E. coli did not affect the growth and cell morphology. Immunofluorescence microscopy revealed that MinCHp forms helix-form structures in H. pylori, whereas MinCHp localizes at cell poles and pole of new daughter cell in E. coli. In addition, co-immunoprecipitation showed MinC can interact with MinD but not with FtsZ during mid-exponential stage of H. pylori. Altogether, our results show that MinCHp plays a key role in maintaining proper cell morphology and its function differs from those of MinCEc.

( Asteraceae ) methanol extracts against Helicobacter pylori

African Journals Online (AJOL)

Methanol vehicle did not affect H. pylori growth. Conclusion: The observed antibacterial effect of G. glutinosum extracts may be of benefit as an adjuvant treatment of diseases caused by H. pylori. Key words: Gymnosperma glutinosum, Helicobacter pylori, methanol extract, minimal inhibitory concentration (MIC).

Helicobacter pylori infection and serum ferritin

DEFF Research Database (Denmark)

Berg, Gabriele; Bode, G; Blettner, M

2001-01-01

OBJECTIVE: Helicobacter pylori may possibly affect the iron metabolism by occult bleeding, impaired absorption of non-hem iron, and by scavenging hem iron or ferritin, as some studies have suggested. The aim of this study was to analyze the association between H. pylori infection and serum ferritin...... in 1987/1988. The examination included a detailed questionnaire on medical history and lifestyle factors, a 7-day food record, and blood samples. Infection with H. pylori was measured serologically by ELISA and Westernblot. RESULTS: In total, 39.2% of 1806 persons aged 18 to 89 yr included in the study...... were H. pylori positive, of whom 57.6% had an infection with a CagA-positive H. pylori strain. Age- and sex-adjusted geometric mean of ferritin was 54.5 microg/dl among H. pylori-infected compared with 63.8 microg/dl among uninfected persons. A multiple linear regression model with log...

Alcohol consumption and Helicobacter pylori infection

DEFF Research Database (Denmark)

Brenner, H; Berg, Gabriele; Lappus, N

1999-01-01

Alcohol has strong antimicrobial activity and stimulates gastric acid secretion. Alcohol consumption may therefore compromise the living conditions of Helicobacter pylori in the stomach. We assessed the relation of alcohol consumption with H. pylori infection among 1,785 participants ages 18...... prevalence of H. pylori infection was 39.2%. There was a clear inverse dose-response-relation between reported alcohol consumption and H. pylori infection. The relation persisted after control for potential confounding factors. The adjusted prevalence ratios (95% confidence intervals) for H. pylori infection...... among persons who consumed up to 10, 10 to 20, and more than 20 gm of alcohol per day compared with non-drinkers were 0.93 (0.77-1.13), 0.82 (0.65-1.04), and 0.71 (0.55-0.92). The inverse relation between alcohol consumption and H. pylori infection was even stronger when individuals with an indication...

Helicobacter pylori: From Infection to Cure

Directory of Open Access Journals (Sweden)

ABR Thomson

1996-01-01

Full Text Available Over 380 abstracts, presentations and posters of recent advances were highlighted at the European and International Helicobacter pylori meeting held July 7 to 9, 1995 in Edinburgh, Scotland. New advances abound, with major interest focusing on the simple, safe, inexpensive new `gold standard’ for H pylori eradication therapy: a single week of tid omeprazole 20 mg, metronidazole 400 mg and clarithromycin 250 mg, or omeprazole 20 mg, amoxicillin 1000 mg and clarithromycin 500 mg. To avoid false negative results, two biopsies must be taken from the antrum and two from the gastric body at least four weeks after completion of eradication therapy, and ideally should be supplemented with at least one further H pylori test such as a biopsy for urease activity or culture, or a urea breath test. While most patients with a gastric or duodenal ulcer (DU who do not consume nonsteroidal anti-inflammatory drugs are infected with H pylori, the association is much less apparent in those with a DU who present with an upper gastrointestinal hemorrhage. H pylori eradication for nonulcer dyspepsia is not widely recommended, and the patient with a DU given effective H pylori eradication who presents with dyspepsia likely has erosive esophagitis rather than recurrent DU or H pylori. Gastroenterologists are at increased risk of H pylori infection, particularly older gastroenterologists who are very busy endoscopists.

Helicobacter pylori Peptidyl Prolyl Isomerase Expression Is Associated with the Severity of Gastritis.

Science.gov (United States)

Oghalaie, Akbar; Saberi, Samaneh; Esmaeili, Maryam; Ebrahimzadeh, Fatemeh; Barkhordari, Farzaneh; Ghamarian, Abdolreza; Tashakoripoor, Mohammad; Abdirad, Afshin; Eshagh Hosseini, Mahmoud; Khalaj, Vahid; Mohammadi, Marjan

2016-12-01

Helicobacter pylori secretory peptidyl prolyl isomerase, HP0175, is progressively identified as a pro-inflammatory and pro-carcinogenic protein, which serves to link H. pylori infection to its more severe clinical outcomes. Here, we have analyzed host HP0175-specific antibody responses in relation to the severity of gastritis. The HP0175 gene fragment was PCR-amplified, cloned, expressed and purified by Ni-NTA affinity chromatography. Serum antigen-specific antibody responses of non-ulcer dyspeptic patients (N = 176) against recombinant HP0175 were detected by western blotting. The infection status of these subjects was determined by rapid urease test, culture, histology, and serology. The grade of inflammation and stage of atrophy were scored blindly according to the OLGA staging system. The recombinant HP0175 (rHP0175) was expressed as a ~35 kDa protein and its identity was confirmed by western blotting using anti-6X His tag antibody and pooled H. pylori-positive sera. Serum IgG antibodies against rHP0175 segregated our patients into two similar-sized groups of sero-positives (90/176, 51.1 %) and sero-negatives (86/176, 48.9 %). The former presented with higher grades of gastric inflammation (OR = 4.4, 95 % CI = 1.9-9.9, P = 0.001) and stages of gastric atrophy (OR = 18.3, 95 %CI = 1.4-246.6, P = 0.028). Our findings lend further support to the pro-inflammatory nature of H. pylori peptidyl prolyl isomerase (HP0175) and recommends this antigen as a non-invasive serum biomarker of the severity of H. pylori-associated gastritis.

Study of Cyclooxygenase-2 Expression in Sprague Dawley Rat Gastric Cancer Induced by H. Pylori

Directory of Open Access Journals (Sweden)

F Aeini

2012-05-01

Full Text Available

Background and Objectives: Gastric cancer is one of the most common gastrointestinal tumors; the incidence and mortality of gastric cancer are on the increase nowadays. Helicobacter pylori(H.Pylori causes chronic active gastritis and peptic ulcer disease. Cycloocygenase-2 (COX-2 is the central enzyme in the biosynthetic pathway to prostaglandins. Studies from different laboratories suggested that over-expression of COX-2 was detected in colon and other tumors. To obtain direct evidence concerning this relationship, we investigated the immunohistochemical findings of gastric mucosa using an animal model of gastric cancer induced by H. pylori in sprague dawley rat. Methods: The rats were randomly assigned into three groups(n=5. Those of experimental group2 were given MNU. one week after completion of MNU administration, rats in experimental groups 1 were inoculated with H. pylori three times every other day. Rats in control group(group 3 received neither MNU nor H. pylori. Rats of groups 1, 2, and control group were maintained on standard diets throughout the experiment. Rat were weighed and sacrificed under anesthesia with ether at 20 weeks after infection. One half of the excised stomachs, were fixed in neutral-buffered 10% formalin and were cut into approximately six strips, which were processed by standard methods, embedded in paraffin, sectioned at 6 µm, and stained with hematoxylin and eosin (H&E and immunohistochemistry for Cox-2 protein detection. To confirm H. pylori infection, samples ( 3-mm² of stomach mucosa transferred to appropriate medium  and Colonies were identified by characteristic Gram’s stain morphology, and by urease, catalase, and oxidase activity sample was also placed into the gel of a rapid urease test kit. Results: Data showed a significant decrease of animal body weight in experimental groups compared with control group

Evaluation of a new vaccine based on pDNA and recombinant protein against Helicobacter pylori

OpenAIRE

Amaral, Maria Rita Rebocho Lopes do

2012-01-01

Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina Helicobacter pylori is a bacterium capable of surviving and infecting a healthy human stomach and it is estimated that infect more than a half of world population. Despite of being almost always asymptomatic, in some cases, the infection can evolve to several gastric disease as chronic gastritis, peptic ulcers, gastric cancer and MALT lymphoma. Vaccination against H. pylori is a promising option due to emerg...

A novel nanobody against urease activity of Helicobacter pylori.

Science.gov (United States)

Ardekani, Leila Safaee; Gargari, Seyed Latif Mousavi; Rasooli, Iraj; Bazl, Masoumeh Rajabi; Mohammadi, Mohammad; Ebrahimizadeh, Walead; Bakherad, Hamid; Zare, Hamed

2013-09-01

Helicobacter pylori infection is associated with gastritis and in some cases with gastric and duodenal ulcers, and even adenocarcinoma. Antibiotic therapy has significant limitations, such as the high cost and the emergence of antibiotic-resistant strains, generating the need for new treatments. The administration of antibody against H. pylori is a new effective therapeutic strategy. In this study, we successfully developed a single-variable domain of heavy chain antibody against recombinant UreC. A VHH phagemid library was constructed from immune camel heavy chain antibodies. The nanobodies were displayed on M13 phage. Library selection was performed against UreC recombinant protein. A specific single-variable domain of heavy chain antibody against UreC was screened in five rounds of panning. The nanobody with the highest score in the phage ELISA was selected for soluble expression. The nanobody was purified with a nickel-nitrilotriacetic acid (Ni-NTA) column and confirmed with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. Affinity, specificity, and urease inhibitory properties of the nanobody were assayed. Here we showed the isolation and purification of a specific nanobody with high affinity against UreC recombinant protein that can inhibit urease activity. The isolated UreC nanobody can specifically detect and bind to UreC and inhibit urease activity. This nanobody could be a novel class of treatment measure against H. pylori infection. Copyright © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Outer membrane biogenesis in Helicobacter pylori: A deviation from the paradigm

Directory of Open Access Journals (Sweden)

George W. Liechti

2012-04-01

Full Text Available The bacterial pathogen Helicobacter pylori is capable of colonizing the gastric mucosa of the human stomach using a variety of factors associated with or secreted from its outer membrane (OM. Lipopolysaccharide (LPS and numerous outer membrane proteins have been shown to be involved in adhesion and immune stimulation/evasion. Many of these factors are essential for colonization and/or pathogenesis in a variety of animal models. Despite this wide array of potential targets present on the bacterial surface, the ability of H. pylori to vary its outer membrane profile limits the effectiveness of vaccines that use any single one of these components. However, it has become evident that the proteins comprising the complexes that transport the majority of these molecules to the OM are highly conserved and often essential. The field of membrane biogenesis has progressed remarkably in the last few years, and the possibility now exists for targeting the mechanisms by which β-barrel proteins, lipoproteins, and LPS are transported to the OM, resulting in loss of bacterial fitness and significant altering of membrane permeability. In this review, the OM transport machinery for LPS, lipoproteins, and outer membrane proteins are discussed. While the principal investigations of these transport mechanisms have been conducted in Escherichia coli and Neisseria meningitidis, here these systems will be presented in the genetic context of ε- proteobacteria. Bioinformatic analysis reveals that minimalist genomes, such as that of Helicobacter pylori, offer insight into the smallest number of components required for these essential pathways to function. Interestingly, in the majority of ε-proteobacteria, while the inner and outer membrane associated apparatus of LPS, lipoprotein, and OM protein transport pathways appear to all be intact, most of the components associated with the periplasmic compartment are either missing or are almost unrecognizable when compared to

Characteristics of Helicobacter pylori-positive and Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma and their influence on clinical outcome.

Science.gov (United States)

Choi, Yoon Jin; Kim, Nayoung; Paik, Jin Ho; Kim, Jung Mogg; Lee, Sang Hyub; Park, Young Soo; Hwang, Jin-Hyeok; Kim, Jin-Wook; Jeong, Sook-Hyang; Lee, Dong Ho; Jung, Hyun Chae

2013-06-01

To compare clinicopathologic and molecular characteristics of low-grade gastric mucosa-associated lymphoid tissue lymphoma depending on Helicobacter pylori positivity and to find out a predictive factor for unresponsiveness to Helicobacter pylori eradication therapy in Korea. A total of 53 Helicobacter pylori-positive and 13 negative mucosa-associated lymphoid tissue lymphoma patients were enrolled, and tissues from 21 patients were investigated to examine the presence of t(11;18)(q21;q21) with fluorescence in situ hybridization. Clinicopathologic features such as the endoscopic appearance, dominant site of lesion, depth of invasion, clinical stage, and the existence of MALT1 gene rearrangement were compared between these two groups. Fifty-six patients who underwent H. pylori eradication therapy were divided into responder and nonresponder groups. The two groups were analyzed to calculate odds ratios for resistance to the eradication. Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma patients averaged a more advanced clinical stage than H. pylori-positive (p = .023) patients. The frequency of t(11;18)/API2-MALT1 did not differ between H. pylori-positive (45.5%) and H. pylori-negative cases (55.6%). Thirty-eight of 51 (74.5%) H. pylori-positive patients achieved complete regression after the eradication, while 2 of 5 (40%) H. pylori-negative patients obtained regression. Presence of lesions in both distal and proximal parts of stomach (p = .041) and bearing of t(11;18)(q21;q21) (p = .007) were predictors for nonresponsiveness for H. pylori eradication. Helicobacter pylori eradication could be performed as a primary therapy regardless of H. pylori status, and assessing t(11;18)/API2-MALT1 would be considered after failure to remission by H. pylori eradication. © 2013 John Wiley & Sons Ltd.

3rd BRAZILIAN CONSENSUS ON Helicobacter pylori

Directory of Open Access Journals (Sweden)

Luiz Gonzaga Coelho

2013-04-01

Full Text Available Significant progress has been obtained since the Second Brazilian Consensus Conference on Helicobacter pylori Infection held in 2004, in São Paulo, SP, Brazil, and justify a third meeting to establish updated guidelines on the current management of H. pylori infection. The Third Brazilian Consensus Conference on H pylori Infection was organized by the Brazilian Nucleus for the Study of Helicobacter, a Department of the Brazilian Federation of Gastroenterology and took place on April 12-15, 2011, in Bento Gonçalves, RS, Brazil. Thirty-one delegates coming from the five Brazilian regions and one international guest, including gastroenterologists, pathologists, epidemiologists, and pediatricians undertook the meeting. The participants were allocated in one of the five main topics of the meeting: H pylori, functional dyspepsia and diagnosis; H pylori and gastric cancer; H pylori and other associated disorders; H pylori treatment and retreatment; and, epidemiology of H pylori infection in Brazil. The results of each subgroup were submitted to a final consensus voting to all participants. Relevant data were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded. Seventy per cent and more votes were considered as acceptance for the final statement. This article presents the main recommendations and conclusions to guide Brazilian doctors involved in the management of H pylori infection.

Screening markers for chronic atrophic gastritis in Chiapas, Mexico.

Science.gov (United States)

Ley, C; Mohar, A; Guarner, J; Herrera-Goepfert, R; Figueroa, L S; Halperin, D; Parsonnet, J

2001-02-01

Intestinal-type gastric adenocarcinomas usually are preceded by chronic atrophic gastritis. Studies of gastric cancer prevention often rely on identification of this condition. In a clinical trial, we sought to determine the best serological screening method for chronic atrophic gastritis and compared our findings to the published literature. Test characteristics of potential screening tests (antibodies to Helicobacter pyloni or CagA, elevated gastrin, low pepsinogen, increased age) alone or in combination were examined among consecutive subjects enrolled in a study of H. pylori and preneoplastic gastric lesions in Chiapas, Mexico; 70% had chronic atrophic gastritis. English-language articles concerning screening for chronic atrophic gastritis were also reviewed. Sensitivity for chronic atrophic gastritis was highest for antibodies to H. pylori (92%) or CagA, or gastrin levels >25 ng/l (both 83%). Specificity, however, was low for these tests (18, 41, and 22%, respectively). Pepsinogen levels were highly specific but insensitive markers of chronic atrophic gastritis (for pepsinogen I gastritis screening. However, no screening test was both highly sensitive and highly specific for chronic atrophic gastritis.

[Helicobacter pylori -- 2010].

Science.gov (United States)

Buzás, György Miklós

2010-12-05

Helicobacter pylori, discovered 27 years ago, has remained the most prevalent infectious agent in the world. In the author's hypothesis, the increase of peptic ulcer prevalence in the 19-20th century could be attributable to the extended worldwide use of gastric tubes for secretory testing which led to the iatrogenic transmission of pathogenic strains. Helicobacter pylori outer membrane proteins (OMP), and duodenal ulcer promoting (dupA) proteins were identified as novel virulence factors, leading to the production of pro-inflammatory cytokines, which could be future targets of therapy. There is no ideal first-line eradication of the infection and according to expert's opinion, the efficiency of these regimens has fallen gradually in recent years to unacceptably low levels; however, in the author's opinion this is a multifactorial phenomenon which can not be generalized. As alternative drugs, the efficiency of levofloxacin, furazolidone and rifabutin has been proven by meta-analyses. Sequential and bismuth-free quadruple therapies, although highly efficient, are not yet used on a large scale. The recurrence of the infection is 2.27%/year in developed and of 13.0%/year in developing countries. Spontaneous eradication occurred in 8-20% of the children and 5-11% of adults. The prevalence of clarithromycin resistance is increasing worldwide. In Hungary, it has reached 10.9% in county cities, according to a national survey. In a district of Budapest called Ferencváros, the prevalence between 2005 and 2009 was 16-22%, with no increasing trend. The development of enzymatic inhibitors (urease, carbonic anhydrase and gamma-glutamyl transpeptidase), modified antibiotics and efflux pump inhibitors seem promising ways because these compounds do not lead to resistance; however, none have yet been used in humans.

Relationship between childhood asthma and Helicobacter pylori infection

Directory of Open Access Journals (Sweden)

Ying Wu

2016-07-01

Full Text Available Objective: To investigate the correlation between childhood asthma and Helicobacter pylori infection. Methods: A total of 80 children with asthma who were treated in our hospital from May 2012 to May 2015 were selected as the research subjects, and 40 cases of healthy children were selected as control group, the Helicobacter pylori infection of the two groups of patients were compared, the double antibody sandwich enzyme-linked immunosorbent assay was used to detect the serum Helicobacter pylori-IgG, Helicobacter pylori-CagAIgG, IL-4, Helicobacter pylori, IFN-γ and IL-1β, etc., and the correlation between Helicobacter pylori infection and asthma was analyzed. Results: The positive rates of Helicobacter pylori infection in asthma group and children in attack stage were significantly higher than those in control group and children in remission stage (P<0.05. The positive rates of serum Helicobacter pylori-IgG and Helicobacter pylori-CagAIgG in asthma group and children in attack stage were significantly lower than those in control group and children in remission stage (P<0.05. The serum levels of IFN-γ in asthma group and children in attack stage were significantly lower than those in control group and children in remission stage, IL-4 and IL-1β levels in the former were significantly higher than those in the latter (P<0.05. Helicobacter pylori infection positive had significant positive correlation with IL-1β concentration (r=0.75, P<0.05. Conclusions: Helicobacter pylori infection in children has significant positive correlation with the incidence of asthma, suggesting that Helicobacter pylori infection has a certain protective effect on childhood asthma, but persistent Helicobacter pylori infection in children with asthma can aggravate the immune disorder, which is the main reason for the difficulty of treatment of asthma.

Helicobacter pylori-coccoid forms and biofilm formation

DEFF Research Database (Denmark)

Andersen, Leif Percival; Rasmussen, Lone

2009-01-01

be detected by PCR in water supplies. There is no substantial evidence for viable H. pylori persisting in water supplies. Epidemiological studies suggest that environmental water is a risk factor for H. pylori infection when compared with tap water, and formation of H. pylori biofilm cannot be excluded....... Helicobacter pylori does not seem to take part in biofilm formation in the oral cavity even though the bacterium may be detected....

Structural characterization of Helicobacter pylori dethiobiotin synthetase reveals differences between family members

Energy Technology Data Exchange (ETDEWEB)

Porebski, Przemyslaw J.; Klimecka, Maria; Chruszcz, Maksymilian; Nicholls, Robert A.; Murzyn, Krzysztof; Cuff, Marianne E.; Xu, Xiaohui; Cymborowski, Marcin; Murshudov, Garib N.; Savchenko, Alexei; Edwards, Aled; Minor, Wladek (MCSG); (UV); (MRC)

2012-07-11

Dethiobiotin synthetase (DTBS) is involved in the biosynthesis of biotin in bacteria, fungi, and plants. As humans lack this pathway, DTBS is a promising antimicrobial drug target. We determined structures of DTBS from Helicobacter pylori (hpDTBS) bound with cofactors and a substrate analog, and described its unique characteristics relative to other DTBS proteins. Comparison with bacterial DTBS orthologs revealed considerable structural differences in nucleotide recognition. The C-terminal region of DTBS proteins, which contains two nucleotide-recognition motifs, differs greatly among DTBS proteins from different species. The structure of hpDTBS revealed that this protein is unique and does not contain a C-terminal region containing one of the motifs. The single nucleotide-binding motif in hpDTBS is similar to its counterpart in GTPases; however, isothermal titration calorimetry binding studies showed that hpDTBS has a strong preference for ATP. The structural determinants of ATP specificity were assessed with X-ray crystallographic studies of hpDTBS-ATP and hpDTBS-GTP complexes. The unique mode of nucleotide recognition in hpDTBS makes this protein a good target for H. pylori-specific inhibitors of the biotin synthesis pathway.

Antiadhesive Properties of Abelmoschus esculentus (Okra) Immature Fruit Extract against Helicobacter pylori Adhesion

Science.gov (United States)

Shevtsova, Anna; Glocker, Erik; Borén, Thomas; Hensel, Andreas

2014-01-01

Background Traditional Asian and African medicine use immature okra fruits (Abelmoschus esculentus) as mucilaginous food to combat gastritis. Its effectiveness is due to polysaccharides that inhibit the adhesion of Helicobacter pylori to stomach tissue. The present study investigates the antiadhesive effect in mechanistic detail. Methodology A standardized aqueous fresh extract (Okra FE) from immature okra fruits was used for a quantitative in vitro adhesion assay with FITC-labled H. pylori J99, 2 clinical isolates, AGS cells, and fluorescence-activated cell sorting. Bacterial adhesins affected by FE were pinpointed using a dot-blot overlay assay with immobilized Lewisb, sialyl-Lewisa, H-1, laminin, and fibronectin. 125I-radiolabeled Okra FE polymer served for binding studies to different H. pylori strains and interaction experiments with BabA and SabA. Iron nanoparticles with different coatings were used to investigate the influence of the charge-dependence of an interaction on the H. pylori surface. Principal findings Okra FE dose-dependently (0.2 to 2 mg/mL) inhibited H. pylori binding to AGS cells. FE inhibited the adhesive binding of membrane proteins BabA, SabA, and HpA to its specific ligands. Radiolabeled compounds from FE bound non-specifically to different strains of H. pylori, as well as to BabA/SabA deficient mutants, indicating an interaction with a still-unknown membrane structure in the vicinity of the adhesins. The binding depended on the charge of the inhibitors. Okra FE did not lead to subsequent feedback regulation or increased expression of adhesins or virulence factors. Conclusion Non-specific interactions between high molecular compounds from okra fruits and the H. pylori surface lead to strong antiadhesive effects. PMID:24416297

Controversies in the Helicobacter pylori/duodenal ulcer story.

Science.gov (United States)

Hobsley, Michael; Tovey, Frank I; Holton, John

2008-12-01

In patients with Helicobacter pylori-positive duodenal ulcer (DU), the organism must be eradicated to achieve rapid, stable healing. However, evidence is against much else that is commonly accepted. (1) Does H. pylori cause the ulcer? Evidence against includes archaeopathology, geographical prevalence, temporal relationships and H. pylori-negative DU patients. DU can recur after eradication of H. pylori infection, and DUs may remain healed after reduction of acid secretion despite persistent infection. The faster healing of ulcers when H. pylori has been eradicated is due to the organism's interference with neoangiogenesis and the healing of wounded epithelial cells. (2) Does H. pylori infection persist until pharmacologically eradicated? Studies based on current infection show that H. pylori infection is a labile state that can change in 3 months. High rates of gastric acid secretion result in spontaneous cure, whereas low rates permit re-infection. Hydrochloric acid, necessary for producing a DU, is strongly associated with the likelihood of an ulcer. At the start, patients owe their ulcer to gastric hypersecretion of hydrochloric acid; approximately 60% may be H. pylori-negative. If acid is suppressed, the less acid milieu encourages invasion by H. pylori, especially if the strain is virulent.

What Do We Do about Helicobacter pylori?

Directory of Open Access Journals (Sweden)

CJ Hawkey

1999-01-01

Full Text Available Heliobacter pylori and nonsteroidal anti-inflammatory drugs (NSAIDs cause ulcers by different mechanisms. Under some circumstances, patients infected with H pylori may be less prone to NSAID-associated ulcers than those who are H pylori-negative. Eradication trials have yielded differing results. However, those who have studied patients who have a past history of ulcer disease and are already established on NSAIDs have shown no benefit from H pylori eradication.

EGFR tyrosine kinase inhibitory peptide attenuates Helicobacter pylori-mediated hyper-proliferation in AGS enteric epithelial cells

Energy Technology Data Exchange (ETDEWEB)

Himaya, S.W.A. [Marine Bio-Process Research Center, Pukyong National University, Nam-Gu, Busan, 608-737 (Korea, Republic of); Dewapriya, Pradeep [Department of Chemistry, Pukyong National University, Nam-Gu, Busan, 608-737 (Korea, Republic of); Kim, Se-Kwon, E-mail: sknkim@pknu.ac.kr [Marine Bio-Process Research Center, Pukyong National University, Nam-Gu, Busan, 608-737 (Korea, Republic of); Department of Chemistry, Pukyong National University, Nam-Gu, Busan, 608-737 (Korea, Republic of)

2013-06-15

Helicobacter pylori infection is one of the most critical causes of stomach cancer. The current study was conducted to explore the protective effects of an isolated active peptide H-P-6 (Pro-Gln-Pro-Lys-Val-Leu-Asp-Ser) from microbial hydrolysates of Chlamydomonas sp. against H. pylori-induced carcinogenesis. The peptide H-P-6 has effectively suppressed H. pylori-induced hyper-proliferation and migration of gastric epithelial cells (AGS). However, the peptide did not inhibit the viability of the bacteria or invasion into AGS cells. Therefore, the effect of the peptide on regulating H. pylori-induced molecular signaling was investigated. The results indicated that H. pylori activates the EGFR tyrosine kinase signaling and nuclear translocation of the β-catenin. The EGFR activation has led to the up-regulation of PI3K/Akt signaling pathway. Moreover, the nuclear translocation levels of β-catenin were significantly increased as a result of Akt mediated down-regulation of GSK3/β protein levels in the cytoplasm. Both of these consequences have resulted in increased expression of cell survival and migration related genes such as c-Myc, cyclin-D, MMP-2 and matrilysin. Interestingly, the isolated peptide potently inhibited H. pylori-mediated EGFR activation and thereby down-regulated the subsequent P13K/Akt signaling leading to β-catenin nuclear translocation. The effect of the peptide was confirmed with the use of EGFR tyrosine kinase inhibitor AG1487 and molecular docking studies. Collectively this study identifies a potent peptide which regulates the H. pylori-induced hyper-proliferation and migration of AGS cells at molecular level. - Highlights: • Chlamydomonas sp. derived peptide H-P-6 inhibits H. pylori-induced pathogenesis. • H-P-6 suppresses H. pylori-induced hyper-proliferation and migration of AGS cells. • The peptide inhibits H. pylori-induced EGFR activation.

Histo-blood group carbohydrates as facilitators for infection by Helicobacter pylori.

Science.gov (United States)

Brandão de Mattos, Cinara Cássia; de Mattos, Luiz Carlos

2017-09-01

Helicobacter pylori infect millions of people around the world. It occupies a niche in the human gastrointestinal tract characterized by high expression of a repertoire of carbohydrates. ABO and Lewis histo-blood group systems are controlled by genes coding for functional glycosyltransferases which synthesize great diversity of related fucosylated carbohydrate in different tissues, including gastrointestinal mucosa, and exocrine secretions. The structural diversity of histo-blood group carbohydrates is highly complex and depends on epistatic interactions among gene-encoding glycosyltransferases. The histo-blood group glycosyltransferases act in the glycosylation of proteins and lipids in the human gastrointestinal tract allowing the expression of a variety of potential receptors in which H. pylori can adhere. These oligosaccharide molecules are part of the gastrointestinal repertoire of carbohydrates which act as potential receptors for microorganisms, including H. pylori. This Gram-negative bacillus is one of the main causes of the gastrointestinal diseases such as chronic active gastritis, peptic ulcer, and cancer of stomach. Previous reports showed that some H. pylori strains use carbohydrates as receptors to adhere to the gastric and duodenal mucosa. Since some histo-blood group carbohydrates are highly expressed in one but not in others histo-blood group phenotypes it has pointed out that quantitative differences among them influence the susceptibility to diseases caused by H. pylori. Additionally, some experiments using animal model are helping us to understand how this bacillus explore histo-blood group carbohydrates as potential receptors, offering possibility to explore new strategies of management of infection, disease treatment, and prevention. This text highlights the importance of structural diversity of ABO and Lewis histo-blood group carbohydrates as facilitators for H. pylori infection. Copyright © 2017 Elsevier B.V. All rights reserved.

A Helicobacter pylori TolC efflux pump confers resistance to metronidazole

NARCIS (Netherlands)

van Amsterdam, Karin; Bart, Aldert; van der Ende, Arie

2005-01-01

In Helicobacter pylori, the contribution of efflux proteins to antibiotic resistance is not well established. As translocases that act in parallel may have overlapping substrate specificities, the loss of function of one such translocase may be compensated for by that of another translocase with no

Comparative analysis of the full genome of Helicobacter pylori isolate Sahul64 identifies genes of high divergence.

Science.gov (United States)

Lu, Wei; Wise, Michael J; Tay, Chin Yen; Windsor, Helen M; Marshall, Barry J; Peacock, Christopher; Perkins, Tim

2014-03-01

Isolates of Helicobacter pylori can be classified phylogeographically. High genetic diversity and rapid microevolution are a hallmark of H. pylori genomes, a phenomenon that is proposed to play a functional role in persistence and colonization of diverse human populations. To provide further genomic evidence in the lineage of H. pylori and to further characterize diverse strains of this pathogen in different human populations, we report the finished genome sequence of Sahul64, an H. pylori strain isolated from an indigenous Australian. Our analysis identified genes that were highly divergent compared to the 38 publically available genomes, which include genes involved in the biosynthesis and modification of lipopolysaccharide, putative prophage genes, restriction modification components, and hypothetical genes. Furthermore, the virulence-associated vacA locus is a pseudogene and the cag pathogenicity island (cagPAI) is not present. However, the genome does contain a gene cluster associated with pathogenicity, including dupA. Our analysis found that with the addition of Sahul64 to the 38 genomes, the core genome content of H. pylori is reduced by approximately 14% (∼170 genes) and the pan-genome has expanded from 2,070 to 2,238 genes. We have identified three putative horizontally acquired regions, including one that is likely to have been acquired from the closely related Helicobacter cetorum prior to speciation. Our results suggest that Sahul64, with the absence of cagPAI, highly divergent cell envelope proteins, and a predicted nontransportable VacA protein, could be more highly adapted to ancient indigenous Australian people but with lower virulence potential compared to other sequenced and cagPAI-positive H. pylori strains.

Adherence of Helicobacter pylori to the Gastric Mucosa

Directory of Open Access Journals (Sweden)

Marguerite Clyne

1997-01-01

Full Text Available Bacterial adhesion to the intestinal epithelium is a critical initial step in the pathogenesis of many enteric diseases. Helicobacter pylori is a duodenal pathogen that adheres to the gastric epithelium and causes gastritis and peptic ulceration. The mechanism by which H pylori causes disease has not yet been elucidated but adherence to the gastric mucosa is thought to be an important virulence determinant of the organism. What is known about adherence of H pylori to the gastric mucosa is summarized. Topics discussed are the mechanism of H pylori adherence; in vitro and in vivo models of H pylori infection; and adherence and potential adhesins and receptors for H pylori.

Association between Helicobacter pylori seropositivity and Hepatic Encephalopathy

International Nuclear Information System (INIS)

Behroozian, R.; Faramarzpur, M.; Rahimi, E.

2010-01-01

Objective: The knowledge on Helicobacter pylori (H. pylori) contribution in the pathology of the liver and biliary tract diseases in human is very limited. The aim of this study was to assess the probable association between H. pylori seropositivity and hepatic encephalopathy. Methodology: This is a case control study conducted through three groups, cirrhotics with hepatic encephalopathy (HE), cirrhotics without HE and healthy controls. All subjects were examined serologically for determination of IgG class antibodies to H. pylori based on ELISA technique. Results: H. pylori seropositivity was present in 88% cirrhotic patients with hepatic encephalopathy, 86% cirrhotics without hepatic encephalopathy and 66% healthy controls. Conclusion: According to our results, H. pylori seropositivity rate in cirrhotic patients with or without hepatic encephalopathy was higher than healthy controls. But H. pylori seropositivity rate was not significantly different among cirrhotics with hepatic encephalopathy and those without it.

Helicobacter pylori colonization of the oral cavity: A milestone discovery

Science.gov (United States)

Yee, John KC

2016-01-01

Over the past several years, the severity of Helicobacter pylori (H. pylori) infections has not significantly diminished. After successful eradication, the annual H. pylori recurrence rate is approximately 13% due to oral H. pylori infection. Established clinical diagnostic techniques do not identify an oral etiologic basis of H. pylori prior to gastric infection. There has been disagreement as to whether oral infection of H. pylori exists or not, with no definite conclusion. In medical practice, negative results with the urea breath test suggest that the stomach infection of H. pylori is cured in these patients. In fact, patients can present negative urea breath test results and yet exhibit H. pylori infection due to oral infection. The present paper provides evidence that H. pylori oral infection is nonetheless present, and the oral cavity represents a secondary site for H. pylori colonization. PMID:26811613

Association of Helicobacter pylori infection with gastric cancer.

Science.gov (United States)

Alexander, G A; Brawley, O W

2000-01-01

Helicobacter pylori has generated public health interest since its identification in 1983. Past studies have suggested that the bacterium plays a role in the pathogenesis of gastric cancer. More recent studies support the conclusion that the association of H. pylori with gastric cancer is causal. The purpose of this article is to review the available evidence supporting the association of H. pylori with gastric cancer. We performed a critical review of the relevant literature published in the English language on H. pylori and gastric cancer using MEDLINE, Index Medicus for the years 1985 to 1997. The reference lists of selected articles also were reviewed to capture citations for further pertinent studies. H. pylori is thought to be the major cause of chronic atrophic gastritis. H. pylori gastritis is worldwide in distribution. H. pylori is now categorized by the International Agency for Cancer Research as a group 1 carcinogen, i.e., an agent that is carcinogenic to humans. Several reports from the United States have found the highest frequencies of gastric cancer in geographic areas and populations with the highest rates of acquisition of H. pylori infection. The high prevalence of H. pylori infection has been documented most notably in blacks and Hispanics, who also are at high risk for gastric cancer. New studies that focus on the epidemiology and pathology of H. pylori improve our understanding of its relationship with gastric cancer and advance the development of gastric cancer prevention and control strategies that are proposed.

Lymphoid follicles in children with Helicobacter pylori-negative gastritis

Science.gov (United States)

Broide, Efrat; Richter, Vered; Mendlovic, Sonia; Shalem, Tzippora; Eindor-Abarbanel, Adi; Moss, Steven F; Shirin, Haim

2017-01-01

Purpose The prevalence of Helicobacter pylori gastritis has been declining, whereas H. pylori-negative gastritis has become more common. We evaluated chronic gastritis in children with regard to H. pylori status and celiac disease (CD). Patients and methods Demographic, clinical, endoscopic, and histologic features of children who underwent elective esophagogastroduodenoscopy were reviewed retrospectively. Gastric biopsies from the antrum and corpus of the stomach were graded using the Updated Sydney System. H. pylori presence was defined by hematoxylin and eosin, Giemsa, or immunohistochemical staining and urease testing. Results A total of 184 children (61.9% female) met the study criteria with a mean age of 10 years. A total of 122 (66.3%) patients had chronic gastritis; 74 (60.7%) were H. pylori-negative. Children with H. pylori-negative gastritis were younger (p=0.003), were less likely to present with abdominal pain (p=0.02), and were mostly of non-Arabic origin (p=0.011). Nodular gastritis was found to be less prevalent in H. pylori-negative gastritis (6.8%) compared with H. pylori-positive gastritis (35.4%, pgastritis and lymphoid follicles were associated most commonly with H. pylori. Although less typical, lymphoid follicles were demonstrated in 51.3% of H. pylori-negative patients. The presence or absence of CD was not associated with histologic findings in H. pylori-negative gastritis. Conclusion Our findings suggest that lymphoid follicles are a feature of H. pylori-negative gastritis in children independent of their CD status. PMID:28860835

Helicobacter Pylori : Serological Testing and Treatment in ...

African Journals Online (AJOL)

Purpose: Helicobacter pylori has been strongly associated with dyspepsia and eradication of H. pylori after a non-invasive testing is an integral part of most management guidelines. This study evaluated the benefit of serological testing and treatment of H. pylori in Nigerian patients presenting with uninvestigated dyspepsia.

Oral and gastric Helicobacter pylori: effects and associations.

Science.gov (United States)

Veiga, Nélio; Pereira, Carlos; Resende, Carlos; Amaral, Odete; Ferreira, Manuela; Nelas, Paula; Chaves, Claudia; Duarte, João; Cirnes, Luis; Machado, José Carlos; Ferreira, Paula; Correia, Ilídio J

2015-01-01

This study consisted in the comparison of the prevalence of Helicobacter pylori (H. pylori) present in the stomach and in saliva of a sample of Portuguese adolescents and the assessment of the association between H. pylori infection with socio-demographic variables and prevalence of dental caries. A cross-sectional study was designed including a sample of 447 adolescents aged 12 to 19 years old, attending a public school in Sátão, Portugal. A questionnaire about socio-demographic variables and oral health behaviors was applied. Gastric H. pylori infection was determined using the urease breath test (UBT). Saliva collection was obtained and DNA was extracted by Polymerase Chain Reaction (PCR) in order to detect the presence of oral H. pylori. The prevalence of gastric H. pylori detected by UBT was 35.9%. Within the adolescents with a gastric UBT positive, only 1.9% were positive for oral H. pylori. The presence of gastric H. pylori was found to be associated with age (>15years, Odds ratio (OR)=1.64, 95%CI=1.08-2.52), residence area (urban, OR=1.48, 95%CI=1.03-2.29) and parents´ professional situation (unemployed, OR=1.22, 95%CI=1.02-1.23). Among those with detected dental caries during the intra-oral observation, 37.4% were positive for gastric H. pylori and 40.2% negative for the same bacterial strain (p=0.3). The oral cavity cannot be considered a reservoir for infection of H. pylori. Gastric H. pylori infection was found to be associated with socio-demographic variables such as age, residence area and socioeconomic status.