scholarly journals Enhanced Reduction of Helicobacter pylori Load in Precolonized Mice Treated with Combined Famotidine and Urease-Binding Polysaccharides

2000 ◽  
Vol 44 (9) ◽  
pp. 2492-2497 ◽  
Author(s):  
Faustino C. Icatlo ◽  
Nobutake Kimura ◽  
Hideo Goshima ◽  
Yoshikatsu Kodama
Keyword(s):  
Helicobacter Pylori ◽  
Dextran Sulfate ◽  
Treatment Time ◽  
Bacterial Load ◽  
Positive Control ◽  
Acid Inhibitor ◽  
Enhanced Activity ◽  
H Pylori

ABSTRACT The present study investigated the effect of a model urease-binding polysaccharide in combination with a histamine H2 receptor antagonist on Helicobacter pylori colonization in vivo. Euthymic hairless mice were treated daily with dextran sulfate via drinking water and/or famotidine via intragastric gavage starting at 1 week postchallenge with a CagA+ VacA+ (type 1) strain of H. pylori. Treatment of precolonized mice for 2 weeks with dextran sulfate combined with famotidine yielded a group mean bacterial load (per 100 mg of gastric tissue) of log101.04 CFU, which was significantly lower than those of the famotidine (log10 3.35 CFU, P < 0.01) and dextran sulfate (log10 2.45 CFU, P < 0.05) monotherapy groups and the infected nontreated group (log103.64 CFU, P < 0.01). Eradication was achieved after 2 weeks of treatment in 50% or more of the test mice using drug combinations (1 or 2 weeks of famotidine plus 2 weeks of dextran sulfate) versus none in the monotherapy and positive control groups. The enhanced activity of the drug combination may be related to the daily pattern of transient acid suppression by famotidine inducing periodic bacterial convergence to superficial mucus sites penetrated by dextran sulfate from the lumen. Increased urease-dextran sulfate avidity was observed in vitro in the presence of famotidine and may partly account for the enhanced activity. With potential utility in abbreviating treatment time and eradication of antibiotic-resistant strains, the use of urease-targeted polysaccharides concurrently with a gastric acid inhibitor warrants consideration as an additional component of the standard multidrug chemotherapy of H. pylori infection.

Enhanced fitness of a Helicobacter pylori babA mutant in a murine model

2021 ◽  
Author(s):  
M. Lorena Harvey ◽  
Aung Soe Lin ◽  
Lili Sun ◽  
Tatsuki Koyama ◽  
Jennifer H. B. Shuman ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Outer Membrane Proteins ◽  
Population Diversity ◽  
Fitness Advantage ◽  
Neutral Locus ◽  
Mutant Strains ◽  
Bacterial Fitness ◽  
H Pylori

Helicobacter pylori genomes encode >60 predicted outer membrane proteins (OMPs). Several OMPs in the Hop family act as adhesins, but the functions of most Hop proteins are unknown. To identify hop mutant strains that exhibit altered fitness in vivo compared to fitness in vitro , we used a genetic barcoding method that allowed us to track changes in the proportional abundance of H. pylori strains within a mixed population. We generated a library of hop mutant strains, each containing a unique nucleotide barcode, as well as a library of control strains, each containing a nucleotide barcode in an intergenic region predicted to be a neutral locus unrelated to bacterial fitness. We orogastrically inoculated each of the libraries into mice and analyzed compositional changes in the populations over time in vivo compared to changes detected in the populations during library passage in vitro . The control library proliferated as a relatively stable community in vitro, but there was a reduction in the population diversity of this library in vivo and marked variation in the dominant strains recovered from individual animals, consistent with the existence of a non-selective bottleneck in vivo . We did not identify any OMP mutants exhibiting fitness defects exclusively in vivo without corresponding fitness defects in vitro . Conversely, a babA mutant exhibited a strong fitness advantage in vivo but not in vitro . These findings, when taken together with results of other studies, suggest that production of BabA may have differential effects on H. pylori fitness depending on the environmental conditions.

scholarly journals Lactobacillus johnsonii La1 Attenuates Helicobacter pylori-Associated Gastritis and Reduces Levels of Proinflammatory Chemokines in C57BL/6 Mice

2005 ◽  
Vol 12 (12) ◽  
pp. 1378-1386 ◽  
Author(s):  
Dionyssios N. Sgouras ◽  
Effrosini G. Panayotopoulou ◽  
Beatriz Martinez-Gonzalez ◽  
Kalliopi Petraki ◽  
Spyros Michopoulos ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Lamina Propria ◽  
Serum Levels ◽  
Favorable Effect ◽  
Lactobacillus Johnsonii ◽  
Ags Cells ◽  
Inflammatory Infiltration ◽  
H Pylori

ABSTRACT In clinical settings, Lactobacillus johnsonii La1 administration has been reported to have a favorable effect on Helicobacter pylori-associated gastritis, although the mechanism remains unclear. We administered, continuously through the water supply, live La1 to H. pylori-infected C57BL/6 mice and followed colonization, the development of H. pylori-associated gastritis in the lamina propria, and the levels of proinflammatory chemokines macrophage inflammatory protein 2 (MIP-2) and keratinocyte-derived cytokine (KC) in the serum and gastric tissue over a period of 3 months. We documented a significant attenuation in both lymphocytic (P = 0.038) and neutrophilic (P = 0.003) inflammatory infiltration in the lamina propria as well as in the circulating levels of anti-H. pylori immunoglobulin G antibodies (P = 0.003), although we did not observe a suppressive effect of La1 on H. pylori colonizing numbers. Other lactobacilli, such as L. amylovorus DCE 471 and L. acidophilus IBB 801, did not attenuate H. pylori-associated gastritis to the same extent. MIP-2 serum levels were distinctly reduced during the early stages of H. pylori infection in the La1-treated animals, as were gastric mucosal levels of MIP-2 and KC. Finally, we also observed a significant reduction (P = 0.046) in H. pylori-induced interleukin-8 secretion by human adenocarcinoma AGS cells in vitro in the presence of neutralized (pH 6.8) La1 spent culture supernatants, without concomitant loss of H. pylori viability. These observations suggest that during the early infection stages, administration of La1 can attenuate H. pylori-induced gastritis in vivo, possibly by reducing proinflammatory chemotactic signals responsible for the recruitment of lymphocytes and neutrophils in the lamina propria.

scholarly journals Effects of Oral Vaccination and Immunomodulation by Cholera Toxin on Experimental Helicobacter pylori Infection, Reinfection, and Gastritis

2002 ◽  
Vol 70 (8) ◽  
pp. 4621-4627 ◽  
Author(s):  
S. Raghavan ◽  
A.-M. Svennerholm ◽  
J. Holmgren
Keyword(s):  
Helicobacter Pylori ◽  
Cholera Toxin ◽  
Mononuclear Cells ◽  
Oral Treatment ◽  
Bacterial Load ◽  
Oral Immunization ◽  
Initial Infection ◽  
Fold Reduction ◽  
H Pylori

ABSTRACT Therapeutic vaccination is an attractive strategy to control infection and disease caused by Helicobacter pylori. In mice infected with H. pylori we have studied the protective effect of oral immunization with an H. pylori lysate preparation given together with the mucosal adjuvant cholera toxin (CT), both against the initial infection and against a later reinfection challenge. We have also examined the effects of treatment with the CT adjuvant alone on H. pylori infection and reinfection. Specific immunization with lysate was found to result in a sixfold reduction of the extent (bacterial load) of the primary infection and also to provide similar levels of protection against reinfection. However, these effects were associated with severe postimmunization gastritis. In contrast, oral treatment with CT alone at the time of initial infection, while unable to suppress the initial infection, gave rise to a 20-fold reduction in bacterial load upon reinfection without causing any associated gastric inflammation. Both the infected animals that were specifically immunized and those that were treated with CT only displayed increased in vitro proliferative responses of mononuclear cells to H. pylori antigens. Antibody levels in response to H. pylori were on the other hand only marginally increased after treatment with CT, whereas they were markedly elevated after immunization with lysate plus CT, with a rise in both (Th2-driven) immunoglobulin G1 (IgG1) and, especially, (Th1-driven) IgG2a antibodies. The results illustrate the complex balance between protection and harmful inflammation after postinfection vaccination against H. pylori as studied in a mouse model.

scholarly journals Therapeutic effects of Zuojin Pill on Helicobacter pylori-induced chronic atrophic gastritis through JMJD2B/COX-2/VEGF signaling axis

2020 ◽  
Author(s):  
Shihua Wu ◽  
Chunmei Bao ◽  
Ruilin Wang ◽  
Xiaomei Zhang ◽  
Sijia Gao ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Cell Viability ◽  
Atrophic Gastritis ◽  
Chronic Atrophic Gastritis ◽  
Gastric Mucosal Damage ◽  
Therapeutic Effects ◽  
Cox 2 ◽  
H Pylori

Abstract Background: Zuojin Pill (ZJP), a famous Chinese medicinal formula, widely accepted for treatment of chronic atrophic gastritis (CAG) in China. This study aimed to explore the therapeutic effects and mechanisms of ZJP in Helicobacter pylori (H. pylori) - induced chronic atrophic gastritis (CAG) in vivo and in vitro. Methods: CAG rat model was induced by H. pylori. ZJP (0.63, 1.26, and 2.52 g/kg, respectively) was administered orally for four weeks. Therapeutic effects of ZJP were identified by H&E staining and serum indices. In addition, cell viability, morphology and proliferation were detected by cell counting kit-8 (CCK8) and high-content screening assay (HCS), respectively. Moreover, relative mRNA expression and protein expression related to JMJD2B/COX-2/VEGF axis was detected to investigate the potential mechanisms of ZJP in CAG. Results: Results showed the symptoms (weight loss and gastric mucosa damage) of CAG were alleviated, and the contents of TNF-α in serum was markedly decreased after treating with ZJP. Moreover, cell viability, proliferation and morphology changes of GES-1 cells were ameliorated by ZJP intervention. In addition, proinflammatory genes and JMJD2B/COX-2/VEGF axis related genes were suppressed by ZJP administration in vitro and in vivo. Meanwhile, immunohistochemistry (IHC) and western blot confirmed down-regulation of these genes by ZJP intervention. Conclusion: ZJP treatment can alleviate gastric mucosal damage induced by H. pylori via JMJD2B/COX-2/VEGF axis.

scholarly journals A Novel 3-Deoxy-d-manno-Octulosonic Acid (Kdo) Hydrolase That Removes the Outer Kdo Sugar of Helicobacter pylori Lipopolysaccharide

2005 ◽  
Vol 187 (10) ◽  
pp. 3374-3383 ◽  
Author(s):  
Christopher Stead ◽  
An Tran ◽  
Donald Ferguson ◽  
Sara McGrath ◽  
Robert Cotter ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Lipid A ◽  
In Vitro Assay ◽  
Spectrometric Analysis ◽  
Vitro Assay ◽  
The Core ◽  
H Pylori

ABSTRACT The lipid A domain anchors lipopolysaccharide (LPS) to the outer membrane and is typically a disaccharide of glucosamine that is both acylated and phosphorylated. The core and O-antigen carbohydrate domains are linked to the lipid A moiety through the eight-carbon sugar 3-deoxy-d-manno-octulosonic acid known as Kdo. Helicobacter pylori LPS has been characterized as having a single Kdo residue attached to lipid A, predicting in vivo a monofunctional Kdo transferase (WaaA). However, using an in vitro assay system we demonstrate that H. pylori WaaA is a bifunctional enzyme transferring two Kdo sugars to the tetra-acylated lipid A precursor lipid IVA. In the present work we report the discovery of a Kdo hydrolase in membranes of H. pylori capable of removing the outer Kdo sugar from Kdo2-lipid A. Enzymatic removal of the Kdo group was dependent upon prior removal of the 1-phosphate group from the lipid A domain, and mass spectrometric analysis of the reaction product confirmed the enzymatic removal of a single Kdo residue by the Kdo-trimming enzyme. This is the first characterization of a Kdo hydrolase involved in the modification of gram-negative bacterial LPS.

scholarly journals 3-Pentylcatechol, a Non-Allergenic Urushiol Derivative, Displays Anti-Helicobacter pylori Activity In Vivo

2020 ◽  
Vol 13 (11) ◽  
pp. 384
Author(s):  
Hang Yeon Jeong ◽  
Tae Ho Lee ◽  
Ju Gyeong Kim ◽  
Sueun Lee ◽  
Changjong Moon ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Triple Therapy ◽  
Inflammatory Cells ◽  
Control Group ◽  
Vitro Assay ◽  
Low Concentrations ◽  
H Pylori ◽  
Stomach Mucous Membrane

We previously reported that 3-pentylcatechol (PC), a synthetic non-allergenic urushiol derivative, inhibited the growth of Helicobacter pylori in an in vitro assay using nutrient agar and broth. In this study, we aimed to investigate the in vivo antimicrobial activity of PC against H. pylori growing in the stomach mucous membrane. Four-week-old male C57BL/6 mice (n = 4) were orally inoculated with H. pylori Sydney Strain-1 (SS-1) for 8 weeks. Thereafter, the mice received PC (1, 5, and 15 mg/kg) and triple therapy (omeprazole, 0.7 mg/kg; metronidazole, 16.7 mg/kg; clarithromycin, 16.7 mg/kg, reference groups) once daily for 10 days. Infiltration of inflammatory cells in gastric tissue was greater in the H. pylori-infected group compared with the control group and lower in both the triple therapy- and PC-treated groups. In addition, upregulation of cytokine mRNA was reversed after infection, upon administration of triple therapy and PC. Interestingly, PC was more effective than triple therapy at all doses, even at 1/15th the dose of triple therapy. In addition, PC demonstrated synergism with triple therapy, even at low concentrations. The results suggest that PC may be more effective against H. pylori than established antibiotics.

scholarly journals In Silico and In Vitro Anti-Helicobacter Pylori Effects of Combinations of Phytochemicals and Antibiotics

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3608 ◽  
Author(s):  
Pedro Fong ◽  
Chon-Hou Hao ◽  
Chi-Cheng Io ◽  
Pou-Io Sin ◽  
Li-Rong Meng
Keyword(s):  
Helicobacter Pylori ◽  
In Silico ◽  
Inhibitory Concentration ◽  
Positive Control ◽  
Shikimate Kinase ◽  
Semialdehyde Dehydrogenase ◽  
Class 1 ◽  
H Pylori ◽  
Potential Inhibitors

Helicobacter pylori infection is a WHO class 1 carcinogenic factor of gastric adenocarcinoma. In the past decades, many studies have demonstrated the increasing trend of antibiotic resistance and pointed out the necessity of new effective treatment. This study was aimed at identifying phytochemicals that can inhibit H. pylori and possibly serve as adjuvant treatments. Here, in silico molecular docking and drug-like properties analyses were performed to identify potential inhibitors of urease, shikimate kinase and aspartate-semialdehyde dehydrogenase. These three enzymes are targets of the treatment of H. pylori. Susceptibility and synergistic testing were performed on the selected phytochemicals and the positive control antibiotic, amoxicillin. The in-silico study revealed that oroxindin, rosmarinic acid and verbascoside are inhibitors of urease, shikimate kinase and aspartate-semialdehyde dehydrogenase, respectively, in which, oroxindin has the highest potency against H. pylori, indicated by a minimum inhibitory concentration (MIC) value of 50 μg/mL. A combination of oroxindin and amoxicillin demonstrated additive effects against H. pylori, as indicated by a fractional inhibitory concentration (FIC) value of 0.75. This study identified phytochemicals that deserve further investigation for the development of adjuvant therapeutic agents to current antibiotics against H. pylori.

scholarly journals Helicobacter pylori Containing Only Cytoplasmic Urease Is Susceptible to Acid

1998 ◽  
Vol 66 (11) ◽  
pp. 5060-5066 ◽  
Author(s):  
Partha Krishnamurthy ◽  
Mary Parlow ◽  
Jason B. Zitzer ◽  
Nimish B. Vakil ◽  
Harry L. T. Mobley ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Urease Activity ◽  
Acid Resistance ◽  
Etiologic Agent ◽  
Stationary Phase Culture ◽  
Colonization Factor ◽  
Acid Environment ◽  
H Pylori

ABSTRACT Helicobacter pylori, an important etiologic agent in a variety of gastroduodenal diseases, produces large amounts of urease as an essential colonization factor. We have demonstrated previously that urease is located within the cytoplasm and on the surface of H. pylori both in vivo and in stationary-phase culture. The purpose of the present study was to assess the relative contributions of cytoplasmic and surface-localized urease to the ability of H. pylori to survive exposure to acid in the presence of urea. Toward this end, we compared the acid resistance in vitro of H. pylori cells which possessed only cytoplasmic urease to that of bacteria which possessed both cytoplasmic and surface-localized or extracellular urease. Bacteria with only cytoplasmic urease activity were generated by using freshly subcultured bacteria or by treating repeatedly subcultured H. pylori with flurofamide (1 μM), a potent, but poorly diffusible urease inhibitor. H. pyloriwith cytoplasmic and surface-located urease activity survived in an acid environment when 5 mM urea was present. In contrast, H. pylori with only cytoplasmic urease shows significantly reduced survival when exposed to acid in the presence of 5 mM urea. Similarly,Escherichia coli SE5000 expressing H. pyloriurease and the Ni2+ transport protein NixA, which expresses cytoplasmic urease activity at levels similar to those in wild-typeH. pylori, survived minimally when exposed to acid in the presence of 5 to 50 mM urea. We conclude that cytoplasmic urease activity alone is not sufficient (although cytoplasmic urease activity is likely to be necessary) to allow survival of H. pyloriin acid; the activity of surface-localized urease is essential for resistance of H. pylori to acid under the assay conditions used. Therefore, the mechanism whereby urease becomes associated with the surface of H. pylori, which involves release of the enzyme from bacteria due to autolysis followed by adsorption of the enzyme to the surface of intact bacteria (“altruistic autolysis”), is essential for survival of H. pylori in an acid environment. The ability of H. pylori to survive exposure to low pH is likely to depend on a combination of both cytoplasmic and surface-associated urease activities.

scholarly journals Preliminary study of the toxicity and radioprotective effects of zymosan in vitro and in vivo

2020 ◽  
Author(s):  
Yue-zhi Zhang ◽  
Shu-jing Ge ◽  
Qing-zhen Leng ◽  
Jian-jun Ma ◽  
Hanchen Liu
Keyword(s):  
Flow Cytometry ◽  
Protective Effect ◽  
Cell Viability ◽  
Treatment Time ◽  
Positive Control ◽  
Radioprotective Effect ◽  
X Rays ◽  
Spleen Index

Abstract Background: This study aimed to confirm the cytotoxicity of zymosan in AHH-1 cells and HIECs and to determine the treatment time and dose of zymosan at which it exerts radioprotective effects.Methods: AHH-1 cells and HIECs were administered 0, 20, 40, 80 or 160 μg/mL zymosan. The CCK-8 assay and flow cytometry were used to evaluate cell viability and apoptosis 24 h, 48 h, and 72 h after administration. Furthermore, 12 h before irradiation, the cells were treated with 0, 5, 10, or 20 μg/mL zymosan and then irradiated with 4 Gy X-rays. Cell viability and apoptosis were measured by the CCK-8 assay and flow cytometry at 24 h. In addition, the protective effect of zymosan against radiation in vitro was compared to that of 20 μg/mL LPS as a positive control. In vivo, weight, the spleen index and the thymus index were measured to evaluate the toxicity of 0, 5, 10, 20 and 10 mg/kg zymosan. In addition, rats were treated with 0, 2, 4, 8 or 10 mg/kg zymosan and then irradiated with 7 Gy X-rays. The survival rate, spleen index and thymus index were evaluated. The protective effect of zymosan against radiation in vivo was compared to that of 10 mg/kg LPS a positive control. Results: The viability and apoptosis of cells treated with different doses of zymosan for different treatment times were not different from those of control cells (p<0.05). Furthermore, cell viability and apoptosis were clearly improved after zymosan preadministration (p<0.05). The radioprotective effect of zymosan was dose-dependent. In addition, the viability of cells pretreated with zymosan was higher than that of cells pretreated with LPS, and the apoptosis rate of zymosan-treated cells was lower than that of cells pretreated with LPS (p<0.05). In vivo, weight, the spleen index and the thymus index were significantly decreased by zymosan at a concentration of 20 mg/kg (p<0.05). Further experiments showed that the concentration at which zymosan exerted radioprotective effects was 10 mg/kg. The radioprotective effect of zymosan was better than that of LPS pretreatment (p<0.05). Conclusion: Zymosan is nontoxic to cells and exerts a better radioprotective effect than LPS.

scholarly journals Discovery and Validation of Novel Methylation Markers in Helicobacter pylori-Associated Gastric Cancer

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Huan Wang ◽  
Nian-Shuang Li ◽  
Cong He ◽  
Chuan Xie ◽  
Yin Zhu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gastric Cancer ◽  
Dna Methylation ◽  
Helicobacter Pylori ◽  
Gene Expression Data ◽  
Functional Enrichment ◽  
Expression Data ◽  
H Pylori

Previous studies have shown that abnormal methylation is an early key event in the pathogenesis of most human cancers, contributing to the development of tumors. However, little attention has been given to the potential of DNA methylation patterns as markers for Helicobacter pylori- (H. pylori-) associated gastric cancer (GC). In this study, an integrated analysis of DNA methylation and gene expression was conducted to identify some potential key epigenetic markers in H. pylori-associated GC. DNA methylation data of 28 H. pylori-positive and 168 H. pylori-negative GC samples were compared and analyzed. We also analyzed the gene expression data of 18 H. pylori-positive and 145 H. pylori-negative GC cases. Finally, the results were verified by in vitro and in vivo experiments. A total of 5609 differentially methylated regions associated with 2454 differentially methylated genes were identified. A total of 228 differentially expressed genes were identified from the gene expression data of H. pylori-positive and H. pylori-negative GC cases. The screened genes were analyzed for functional enrichment. Subsequently, we obtained 28 genes regulated by methylation through a Venn diagram, and we identified five genes (GSTO2, HUS1, INTS1, TMEM184A, and TMEM190) downregulated by hypermethylation. HUS1, GSTO2, and TMEM190 were expressed at lower levels in GC than in adjacent samples ( P < 0.05 ). Moreover, H. pylori infection decreased HUS1, GSTO2, and TMEM190 expression in vitro and in vivo. Our study identified HUS1, GSTO2, and TMEM190 as novel methylation markers for H. pylori-associated GC.

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