Evidence for a Conjugation-Like Mechanism of DNA Transfer in Helicobacter pylori

ABSTRACT Many strains of Helicobacter pylori are naturally competent for transformation in vitro. Since there is a high degree of genetic variation among H. pylori strains, we sought to determine whether mechanisms of DNA exchange other than transformation exist in these organisms. Studies were done with H. pyloricells that each were resistant to two different antibiotics; the procedure used involved mating of cells on plates or in broth, in the absence or presence of DNase. In each experiment, such matings produced progeny with the markers of both parents. Examination of the full resistance profile and random arbitrarily primed DNA PCR (RAPD-PCR) profiles of the progeny indicated that DNA transfer was bidirectional. DNase treatment reduced but did not eliminate transfer; only the presence of both DNase and a membrane separating the cells did so. For progeny derived from matings in the presence of DNase, antibiotic resistance and RAPD profiles indicated that transfer was unidirectional. DNase-treated cell-free supernatants also did not transform, ruling out transduction. These experiments indicate that both a DNase-sensitive mechanism (transformation) and a DNase-resistant conjugation-like mechanism involving cell-to-cell contact may contribute to DNA transfer between H. pylori cells.

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Pan-genomic analyses identify key Helicobacter pylori pathogenic loci modified by carcinogenic host microenvironments

Gut ◽

10.1136/gutjnl-2017-313863 ◽

2017 ◽

Vol 67 (10) ◽

pp. 1793-1804 ◽

Cited By ~ 11

Author(s):

Jennifer M Noto ◽

Abha Chopra ◽

John T Loh ◽

Judith Romero-Gallo ◽

M Blanca Piazuelo ◽

...

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Genetic Variation ◽

Prolonged Exposure ◽

Dietary Factors ◽

High Salt ◽

Premalignant Lesions ◽

H Pylori

ObjectiveHelicobacter pylori is the strongest risk factor for gastric cancer; however, the majority of infected individuals do not develop disease. Pathological outcomes are mediated by complex interactions among bacterial, host and environmental constituents, and two dietary factors linked with gastric cancer risk are iron deficiency and high salt. We hypothesised that prolonged adaptation of H. pylori to in vivo carcinogenic microenvironments results in genetic modification important for disease.DesignWhole genome sequencing of genetically related H. pylori strains that differ in virulence and targeted H. pylori sequencing following prolonged exposure of bacteria to in vitro carcinogenic conditions were performed.ResultsA total of 180 unique single nucleotide polymorphisms (SNPs) were identified among the collective genomes when compared with a reference H. pylori genome. Importantly, common SNPs were identified in isolates harvested from iron-depleted and high salt carcinogenic microenvironments, including an SNP within fur (FurR88H). To investigate the direct role of low iron and/or high salt, H. pylori was continuously cultured in vitro under low iron or high salt conditions to assess fur genetic variation. Exposure to low iron or high salt selected for the FurR88H variant after only 5 days. To extend these results, fur was sequenced in 339 clinical H. pylori strains. Among the isolates examined, 17% (40/232) of strains isolated from patients with premalignant lesions harboured the FurR88H variant, compared with only 6% (6/107) of strains from patients with non-atrophic gastritis alone (p=0.0034).ConclusionThese results indicate that specific genetic variation arises within H. pylori strains during in vivo adaptation to conditions conducive for gastric carcinogenesis.

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Infection with CagA+Helicobacter pylori induces epithelial to mesenchymal transition in human cholangiocytes

10.1101/2020.04.28.066324 ◽

2020 ◽

Cited By ~ 2

Author(s):

Prissadee Thanaphongdecha ◽

Shannon E. Karinshak ◽

Wannaporn Ittiprasert ◽

Victoria H. Mann ◽

Yaovalux Chamgramol ◽

...

Keyword(s):

Helicobacter Pylori ◽

Epithelial To Mesenchymal Transition ◽

Cellular Proliferation ◽

Stem Cell Marker ◽

Migration And Invasion ◽

Cell Contact ◽

Cell Of Origin ◽

Mesenchymal Transition ◽

H Pylori

AbstractRecent reports suggest that the East Asian liver fluke, Opisthorchis viverrini, infection with which is implicated in opisthorchiasis-associated cholangiocarcinoma, serves as a reservoir of Helicobacter pylori. The opisthorchiasis-affected cholangiocytes that line the intrahepatic biliary tract are considered to be the cell of origin of this malignancy. Here, we investigated interactions in vitro among human cholangiocytes, a CagA-positive strain of Helicobacter pylori, and the related bacillus, Helicobacter bilis. Exposure to increasing numbers of H. pylori at 0, 1, 10, 100 bacilli per cholangiocyte induced phenotypic changes including the profusion of thread-like filopodia and a loss of cell-cell contact, in a dose-dependent fashion. In parallel, following exposure to H. pylori, changes were evident in levels of mRNA expression of epithelial to mesenchymal transition (EMT)-encoding factors including snail, slug, vimentin, matrix metalloprotease, zinc finger E-box-binding homeobox, and the cancer stem cell marker CD44. Transcription levels encoding the cell adhesion marker CD24 decreased. Analysis to quantify cellular proliferation, migration and invasion in real time using the xCELLigence approach revealed that exposure to ≥10 H. pylori stimulated migration and invasion by the cholangiocytes through an extracellular matrix. In addition, 10 bacilli of CagA-positive H. pylori stimulated contact-independent colony establishment in soft agar. These findings support the hypothesis that infection with H. pylori contributes to the malignant transformation of the biliary epithelium.

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Infection with Helicobacter pylori Induces Epithelial to Mesenchymal Transition in Human Cholangiocytes

Pathogens ◽

10.3390/pathogens9110971 ◽

2020 ◽

Vol 9 (11) ◽

pp. 971

Author(s):

Prissadee Thanaphongdecha ◽

Shannon E. Karinshak ◽

Wannaporn Ittiprasert ◽

Victoria H. Mann ◽

Yaovalux Chamgramol ◽

...

Keyword(s):

Helicobacter Pylori ◽

Epithelial To Mesenchymal Transition ◽

Cellular Proliferation ◽

Stem Cell Marker ◽

Migration And Invasion ◽

Cell Contact ◽

Cell Of Origin ◽

Mesenchymal Transition ◽

H Pylori

Recent reports suggest that the East Asian liver fluke infection, caused by Opisthorchis viverrini, which is implicated in opisthorchiasis-associated cholangiocarcinoma, serves as a reservoir of Helicobacter pylori. The opisthorchiasis-affected cholangiocytes that line the intrahepatic biliary tract are considered to be the cell of origin of this malignancy. Here, we investigated interactions in vitro among human cholangiocytes, Helicobacter pylori strain NCTC 11637, and the congeneric bacillus, Helicobacter bilis. Exposure to increasing numbers of H. pylori at 0, 1, 10, 100 bacilli per cholangiocyte of the H69 cell line induced phenotypic changes including the profusion of thread-like filopodia and a loss of cell-cell contact, in a dose-dependent fashion. In parallel, following exposure to H. pylori, changes were evident in levels of mRNA expression of epithelial to mesenchymal transition (EMT)-encoding factors including snail, slug, vimentin, matrix metalloprotease, zinc finger E-box-binding homeobox, and the cancer stem cell marker CD44. Analysis to quantify cellular proliferation, migration, and invasion in real-time by both H69 cholangiocytes and CC-LP-1 line of cholangiocarcinoma cells using the xCELLigence approach and Matrigel matrix revealed that exposure to ≥10 H. pylori bacilli per cell stimulated migration and invasion by the cholangiocytes. In addition, 10 bacilli of H. pylori stimulated contact-independent colony establishment in soft agar. These findings support the hypothesis that infection by H.pylori contributes to the malignant transformation of the biliary epithelium.

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The rod-to-coccoid body transformation in cultures of Helicobacter pylori

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100160686 ◽

1990 ◽

Vol 48 (3) ◽

pp. 626-627

Author(s):

A. R. Crooker ◽

W. G. Kraft ◽

T. L. Beard ◽

M. C. Myers

Keyword(s):

Helicobacter Pylori ◽

Growth Cycle ◽

Negative Bacterium ◽

Body Formation ◽

Coccoid Form ◽

Spiral Form ◽

Prolonged Culture ◽

H Pylori ◽

Upper Gastrointestinal

Helicobacter pylori is a microaerophilic, gram-negative bacterium found in the upper gastrointestinal tract of humans. There is strong evidence that H. pylori is important in the etiology of gastritis; the bacterium may also be a major predisposing cause of peptic ulceration. On the gastric mucosa, the organism exists as a spiral form with one to seven sheathed flagella at one (usually) or both poles. Short spirals were seen in the first successful culture of the organism in 1983. In 1984, Marshall and Warren reported a coccoid form in older cultures. Since that time, other workers have observed rod and coccal forms in vitro; coccoid forms predominate in cultures 3-7 days old. We sought to examine the growth cycle of H. pylori in prolonged culture and the mode of coccoid body formation.

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Synthesis and In Vitro Enzymatic Studies of New 3-Aryldiazenyl Indoles as Promising Helicobacter pylori IMPDH Inhibitors

Current Topics in Medicinal Chemistry ◽

10.2174/1568026619666190227212334 ◽

2019 ◽

Vol 19 (5) ◽

pp. 376-382 ◽

Cited By ~ 4

Author(s):

Sachin Jangra ◽

Gayathri Purushothaman ◽

Kapil Juvale ◽

Srimadhavi Ravi ◽

Aishwarya Menon ◽

...

Keyword(s):

Helicobacter Pylori ◽

Bacterial Infections ◽

Immunosuppressive Drugs ◽

Multi Drug Resistance ◽

Metabolic Enzyme ◽

World Population ◽

Inhibitor Molecule ◽

Nucleotide Synthesis ◽

H Pylori

Background & Objective:Helicobacter pylori infection is one of the primary causes of peptic ulcer followed by gastric cancer in the world population. Due to increased occurrences of multi-drug resistance to the currently available antibiotics, there is an urgent need for a new class of drugs against H. pylori. Inosine 5′-monophosphate dehydrogenase (IMPDH), a metabolic enzyme plays a significant role in cell proliferation and cell growth. It catalyses guanine nucleotide synthesis. IMPDH enzyme has been exploited as a target for antiviral, anticancer and immunosuppressive drugs. Recently, bacterial IMPDH has been studied as a potential target for treating bacterial infections. Differences in the structural and kinetic parameters of the eukaryotic and prokaryotic IMPDH make it possible to target bacterial enzyme selectively.Methods:In the current work, we have synthesised and studied the effect of substituted 3-aryldiazenyl indoles on Helicobacter pylori IMPDH (HpIMPDH) activity. The synthesised molecules were examined for their inhibitory potential against recombinant HpIMPDH.Results:In this study, compounds 1 and 2 were found to be the most potent inhibitors amongst the database with IC50 of 0.8 ± 0.02µM and 1 ± 0.03 µM, respectively.Conclusion:When compared to the most potent known HpIMPDH inhibitor molecule C91, 1 was only four-fold less potent and can be a good lead for further development of selective and potent inhibitors of HpIMPDH.

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Synthesis, Molecular Modelling and Antibacterial Activity Against Helicobacter pylori of Novel Diflunisal Derivatives as Urease Enzyme Inhibitors

Letters in Drug Design & Discovery ◽

10.2174/1570180815666180627130208 ◽

2019 ◽

Vol 16 (4) ◽

pp. 392-400 ◽

Cited By ~ 2

Author(s):

Göknil Pelin Coşkun ◽

Teodora Djikic ◽

Sadık Kalaycı ◽

Kemal Yelekçi ◽

Fikrettin Şahin ◽

...

Keyword(s):

Helicobacter Pylori ◽

Antibacterial Activity ◽

Enzyme Inhibitors ◽

Binding Modes ◽

Bacterial Strains ◽

Urease Enzyme ◽

H Pylori ◽

Ulcer Treatment ◽

Main Factor

Background:The main factor for the prolongation of the ulcer treatment in the gastrointestinal system would be Helicobacter pylori infection, which can possibly lead to gastrointestinal cancer. Triple therapy is the treatment of choice by today's standards. However, observed resistance among the bacterial strains can make the situation even worse. Therefore, there is a need to discover new targeted antibacterial therapy in order to make success in the eradication of H. pylori infections.Methods:The targeted therapy rule is to identify the related macromolecules that are responsible for the survival of the bacteria. Thus, 2-[(2',4'-difluoro-4-hydroxybiphenyl-3-yl)carbonyl]-N- (substituted)hydrazinocarbothioamide (3-13) and 5-(2',4'-difluoro-4-hydroxybiphenyl-3-yl)-4- (substituted)-2,4-dihydro-3H-1,2,4-triazole-3-thiones (14-17) were synthesized and evaluated for antibacterial activity in vitro against H. pylori.Results:All of the tested compounds showed remarkable antibacterial activity compared to the standard drugs (Ornidazole, Metronidazole, Nitrimidazin and Clarithromycin). Compounds 4 and 13 showed activity as 2µg/ml MIC value.Conclusion:In addition, we have investigated binding modes and energy of the compounds 4 and 13 on urease enzyme active by using the molecular docking tools.

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Nutrient Deficiency Promotes the Entry of Helicobacter pylori Cells into Candida Yeast Cells

Biology ◽

10.3390/biology10050426 ◽

2021 ◽

Vol 10 (5) ◽

pp. 426

Author(s):

Kimberly Sánchez-Alonzo ◽

Fabiola Silva-Mieres ◽

Luciano Arellano-Arriagada ◽

Cristian Parra-Sepúlveda ◽

Humberto Bernasconi ◽

...

Keyword(s):

Helicobacter Pylori ◽

Nutrient Deficiency ◽

Gastric Epithelium ◽

Yeast Cells ◽

Nutrient Concentrations ◽

Fetal Bovine ◽

H Pylori ◽

Pcr Techniques ◽

Strain Dependent

Helicobacter pylori, a Gram-negative bacterium, has as a natural niche the human gastric epithelium. This pathogen has been reported to enter into Candida yeast cells; however, factors triggering this endosymbiotic relationship remain unknown. The aim of this work was to evaluate in vitro if variations in nutrient concentration in the cultured medium trigger the internalization of H. pylori within Candida cells. We used H. pylori–Candida co-cultures in Brucella broth supplemented with 1%, 5% or 20% fetal bovine serum or in saline solution. Intra-yeast bacteria-like bodies (BLBs) were observed using optical microscopy, while intra-yeast BLBs were identified as H. pylori using FISH and PCR techniques. Intra-yeast H. pylori (BLBs) viability was confirmed using the LIVE/DEAD BacLight Bacterial Viability kit. Intra-yeast H. pylori was present in all combinations of bacteria–yeast strains co-cultured. However, the percentages of yeast cells harboring bacteria (Y-BLBs) varied according to nutrient concentrations and also were strain-dependent. In conclusion, reduced nutrients stresses H. pylori, promoting its entry into Candida cells. The starvation of both H. pylori and Candida strains reduced the percentages of Y-BLBs, suggesting that starving yeast cells may be less capable of harboring stressed H. pylori cells. Moreover, the endosymbiotic relationship between H. pylori and Candida is dependent on the strains co-cultured.

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Putative Cooperative ATP–DnaA Binding to Double-Stranded DnaA Box and Single-Stranded DnaA-Trio Motif upon Helicobacter pylori Replication Initiation Complex Assembly

International Journal of Molecular Sciences ◽

10.3390/ijms22126643 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6643

Author(s):

Pawel Jaworski ◽

Dorota Zyla-Uklejewicz ◽

Malgorzata Nowaczyk-Cieszewska ◽

Rafal Donczew ◽

Thorsten Mielke ◽

...

Keyword(s):

Helicobacter Pylori ◽

Replication Initiation ◽

Dna Unwinding ◽

Rich Region ◽

Initiator Protein ◽

New Class ◽

H Pylori ◽

General Architecture ◽

Dnaa Box

oriC is a region of the bacterial chromosome at which the initiator protein DnaA interacts with specific sequences, leading to DNA unwinding and the initiation of chromosome replication. The general architecture of oriCs is universal; however, the structure of oriC and the mode of orisome assembly differ in distantly related bacteria. In this work, we characterized oriC of Helicobacter pylori, which consists of two DnaA box clusters and a DNA unwinding element (DUE); the latter can be subdivided into a GC-rich region, a DnaA-trio and an AT-rich region. We show that the DnaA-trio submodule is crucial for DNA unwinding, possibly because it enables proper DnaA oligomerization on ssDNA. However, we also observed the reverse effect: DNA unwinding, enabling subsequent DnaA–ssDNA oligomer formation—stabilized DnaA binding to box ts1. This suggests the interplay between DnaA binding to ssDNA and dsDNA upon DNA unwinding. Further investigation of the ts1 DnaA box revealed that this box, together with the newly identified c-ATP DnaA box in oriC1, constitute a new class of ATP–DnaA boxes. Indeed, in vitro ATP–DnaA unwinds H. pylori oriC more efficiently than ADP–DnaA. Our results expand the understanding of H. pylori orisome formation, indicating another regulatory pathway of H. pylori orisome assembly.

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Shedding Light on the African Enigma: In Vitro Testing of Homo sapiens-Helicobacter pylori Coevolution

Microorganisms ◽

10.3390/microorganisms9020240 ◽

2021 ◽

Vol 9 (2) ◽

pp. 240

Author(s):

Bruno Cavadas ◽

Marina Leite ◽

Nicole Pedro ◽

Ana C. Magalhães ◽

Joana Melo ◽

...

Keyword(s):

Gene Expression ◽

Helicobacter Pylori ◽

Host Response ◽

Homo Sapiens ◽

European Ancestry ◽

Genome Wide ◽

Expression Host ◽

H Pylori ◽

Human Ancestry

The continuous characterization of genome-wide diversity in population and case–cohort samples, allied to the development of new algorithms, are shedding light on host ancestry impact and selection events on various infectious diseases. Especially interesting are the long-standing associations between humans and certain bacteria, such as the case of Helicobacter pylori, which could have been strong drivers of adaptation leading to coevolution. Some evidence on admixed gastric cancer cohorts have been suggested as supporting Homo-Helicobacter coevolution, but reliable experimental data that control both the bacterium and the host ancestries are lacking. Here, we conducted the first in vitro coinfection assays with dual human- and bacterium-matched and -mismatched ancestries, in African and European backgrounds, to evaluate the genome wide gene expression host response to H. pylori. Our results showed that: (1) the host response to H. pylori infection was greatly shaped by the human ancestry, with variability on innate immune system and metabolism; (2) African human ancestry showed signs of coevolution with H. pylori while European ancestry appeared to be maladapted; and (3) mismatched ancestry did not seem to be an important differentiator of gene expression at the initial stages of infection as assayed here.

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A High-Throughput Metabolic Microarray Assay Reveals Antibacterial Effects of Black and Red Raspberries and Blackberries against Helicobacter pylori Infection

Antibiotics ◽

10.3390/antibiotics10070845 ◽

2021 ◽

Vol 10 (7) ◽

pp. 845

Author(s):

Candace Goodman ◽

Katrina N. Lyon ◽

Aitana Scotto ◽

Cyra Smith ◽

Thomas A. Sebrell ◽

...

Keyword(s):

Helicobacter Pylori ◽

High Throughput ◽

Antibacterial Properties ◽

Treatment Strategies ◽

Helicobacter Pylori Infection ◽

Antibacterial Effects ◽

Biolog System ◽

Freeze Dried ◽

H Pylori

Helicobacter pylori infection is commonly treated with a combination of antibiotics and proton pump inhibitors. 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 the antibacterial effects of black and red raspberries and blackberries on H. pylori. Freeze-dried powders and organic extracts from black and red raspberries and blackberries were prepared, and high-performance liquid chromatography was used to measure the concentrations of anthocyanins, which are considered the major active ingredients. To monitor antibiotic effects of the berry preparations on H. pylori, a high-throughput metabolic growth assay based on the Biolog system was developed and validated with the antibiotic metronidazole. Biocompatibility was analyzed using human gastric organoids. All berry preparations tested had significant bactericidal effects in vitro, with MIC90 values ranging from 0.49 to 4.17%. Antimicrobial activity was higher for extracts than powders and appeared to be independent of the anthocyanin concentration. Importantly, human gastric epithelial cell viability was not negatively impacted by black raspberry extract applied at the concentration required for complete bacterial growth inhibition. Our data suggest that black and red raspberry and blackberry extracts may have potential applications in the treatment and prevention of H. pylori infection but differ widely in their MICs. Moreover, we demonstrate that the Biolog metabolic assay is suitable for high-throughput antimicrobial susceptibility screening of H. pylori.

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