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 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 The Entner-Doudoroff Pathway Has Little Effect on Helicobacter pylori Colonization of Mice

2003 ◽  
Vol 71 (5) ◽  
pp. 2920-2923 ◽  
Author(s):  
Amy E. Wanken ◽  
Tyrrell Conway ◽  
Kathryn A. Eaton
Keyword(s):  
Helicobacter Pylori ◽  
Wild Type ◽  
Mutant Strains ◽  
H Pylori ◽  
Type Strains

ABSTRACT Helicobacter pylori mutants deficient in 6-phosphogluconate dehydratase (6PGD) were constructed. Colonization densities were lower and minimum infectious doses were higher for mutant strains than for wild-type strains. In spite of better colonization, however, wild-type strains did not displace the mutant in cocolonization experiments. Loss of 6PGD diminishes the fitness of H. pylori in vivo, but the pathway is nonessential for colonization.

scholarly journals Comparison of CXC Chemokines ENA-78 and Interleukin-8 Expression in Helicobacter pylori-Associated Gastritis

2001 ◽  
Vol 69 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Gabriele Rieder ◽  
Wolfgang Einsiedl ◽  
Rudolf A. Hatz ◽  
Manfred Stolte ◽  
Georg A. Enders ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Protein Expression ◽  
Outer Membrane Proteins ◽  
Water Soluble ◽  
Interleukin 8 ◽  
Gastric Epithelium ◽  
Mrna Levels ◽  
Rt Pcr ◽  
H Pylori

ABSTRACT Colonization of the gastric mucosa with Helicobacter pylori is associated with a dense infiltration of granulocytes into the lamina propria in the active phase of gastritis. In this study, we investigated the involvement of epithelial cell-derived neutrophil-activating protein 78 (ENA-78) in development of H. pylori-associated gastritis. Antral biopsies from 27 patients with H. pylori-associated gastritis and 25 from H. pylori-negative individuals were first analyzed for ENA-78 and interleukin-8 (IL-8) mRNA by semiquantitative reverse transcription (RT)-PCR. In H. pylori-positive patients, significantly elevated levels were found for both chemokines (P < 0.05). Only IL-8 mRNA levels differed significantly (P< 0.05) in H. pylori-infected individuals who had serum antibodies for cytotoxin-associated protein CagA versus H. pylori-infected CagA-negative persons. Quantification of ENA-78 transcript levels by competitive RT-PCR yielded a significant 45-fold upregulation for ENA-78 transcripts in biopsies of H. pylori-positive versus H. pylori-negative patients (P < 0.05). In contrast to earlier findings with IL-8, the degree of ENA-78 mRNA upregulation was independent of the grade of activity of gastritis. Immunofluorescence studies on tissues of antral biopsies localized ENA-78 protein expression mainly to the gastric epithelium of H. pylori-positive patients, while control tissues were negative. Upregulation of ENA-78 and IL-8 mRNA and protein expression was also observed in an in vitro system using a gastric adenocarcinoma cell line. Only viable H. pyloriyielded a strong ENA-78 and IL-8 induction, while H. pyloriouter membrane proteins or water-soluble proteins had no significant effect. These data provide evidence for the importance of both IL-8 and ENA-78 in the development and perpetuation of H. pylori-associated gastritis.

scholarly journals Antimicrobial Drug Resistance Genes Do Not Convey a Secondary Fitness Advantage to Calf-Adapted Escherichia coli

2006 ◽  
Vol 72 (1) ◽  
pp. 443-448 ◽  
Author(s):  
Artashes R. Khachatryan ◽  
Dale D. Hancock ◽  
Thomas E. Besser ◽  
Douglas R. Call
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Null Mutant ◽  
Antimicrobial Drug Resistance ◽  
E Coli ◽  
Fitness Advantage ◽  
Antimicrobial Resistance Genes ◽  
Mutant Strains

ABSTRACT Maintenance of antimicrobial drug resistance in bacteria can be influenced by factors unrelated to direct selection pressure such as close linkage to other selectively advantageous genes and secondary advantage conveyed by antimicrobial resistance genes in the absence of drug selection. Our previous trials at a dairy showed that the maintenance of the antimicrobial resistance genes is not influenced by specific antimicrobial selection and that the most prevalent antimicrobial resistance phenotype of Escherichia coli is specifically selected for in young calves. In this paper we examine the role of secondary advantages conveyed by antimicrobial resistance genes. We tested antimicrobial-susceptible null mutant strains for their ability to compete with their progenitor strains in vitro and in vivo. The null mutant strains were generated by selection for spontaneous loss of resistance genes in broth supplemented with fusaric acid or nickel chloride. On average, the null mutant strains were as competitive as the progenitor strains in vitro and in newborn calves (in vivo). Inoculation of newborn calves at the dairy with antimicrobial-susceptible strains of E. coli did not impact the prevalence of antimicrobial-resistant E. coli. Our results demonstrate that the antimicrobial resistance genes are not responsible for the greater fitness advantage of antimicrobial-resistant E. coli in calves, but the farm environment and the diet clearly exert critical selective pressures responsible for the maintenance of antimicrobial resistance genes. Our current hypothesis is that the antimicrobial resistance genes are linked to other genes responsible for differential fitness in dairy calves.

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 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.

scholarly journals A high-throughput metabolic microarray assay reveals antibacterial effects of black and red raspberries and blackberries against Helicobacter pylori infection

2020 ◽  
Author(s):  
Candace Goodman ◽  
Katrina Lyon ◽  
Aitana Scotto ◽  
Mandi M. Roe ◽  
Farimah Moghimpour ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
High Throughput ◽  
Severe Disease ◽  
Antibacterial Properties ◽  
Black Raspberry ◽  
Antibacterial Effects ◽  
Ulcer Disease ◽  
H Pylori

AbstractHelicobacter pylori is an important bacterial pathogen that causes chronic infection of the human stomach, leading to gastritis, peptic ulcer disease and gastric cancer. Treatment with appropriate antibiotics can eliminate H. pylori infection and reduce the risk for severe disease outcomes. However, since H. pylori is becoming increasingly resistant to standard antibiotic regimens, novel treatment strategies are needed. Previous studies have demonstrated that black and red berries may have antibacterial properties. Therefore, we analyzed organic extracts and powders from black and red raspberries and blackberries and determined their antibacterial effects on multiple H. pylori strains. We used high-performance liquid chromatography to measure berry anthocyanins, which are considered the major active ingredients. To monitor antibiotic effects of the berry preparations on H. pylori, we developed a high-throughput metabolic growth assay based on the OmniLog™ system. All berry preparations tested had significant bactericidal effects in vitro, with MIC90 values ranging from 0.49 to 4.17%. We next used human gastric epithelial organoids to evaluate biocompatibility of the berry preparations and showed that black raspberry extract, which had the strongest antimicrobial activity, was non-toxic at the concentration required for complete bacterial growth inhibition. To determine whether dietary black raspberry application could eliminate H. pylori infection in vivo, mice were infected with H. pylori and then were placed on a diet containing 10% black raspberry powder. However, this treatment did not significantly impact bacterial infection rates or gastric pathology. In summary, our data indicate that black and red raspberry and blackberry products have potential applications in the treatment and prevention of H. pylori infection, because of their antibacterial effects and good biocompatibility. However, delivery and formulation of berry compounds needs to be optimized to achieve significant antibacterial effects in vivo.

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