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Helicobacter pylori bacterial populations

ABSTRACT: Sexual reproduction and recombination are essential for the survival of most eukaryotic populations. Until recently, the impact of these processes on the structure of bacterial populations has been largely overlooked. The advent of large-scale whole-genome sequencing and the concomitant development of molecular tools, such as microarray technology, facilitate the sensitive detection of recombination events in bacteria. These techniques are revealing that bacterial populations are comprised of isolates that show a surprisingly wide spectrum of genetic diversity at the DNA level. Our new awareness of this genetic diversity is increasing our understanding of population structures and of how these affect host?pathogen relationships. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set

ORGANISM(S): Helicobacter pylori

PROVIDER: GSE3479 | GEO | 2005/10/20

SECONDARY ACCESSION(S): PRJNA93291

REPOSITORIES: GEO

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Helicobacter pylori bacterial populations

Project description:Sexual reproduction and recombination are essential for the survival of most eukaryotic populations. Until recently, the impact of these processes on the structure of bacterial populations has been largely overlooked. The advent of large-scale whole-genome sequencing and the concomitant development of molecular tools, such as microarray technology, facilitate the sensitive detection of recombination events in bacteria. These techniques are revealing that bacterial populations are comprised of isolates that show a surprisingly wide spectrum of genetic diversity at the DNA level. Our new awareness of this genetic diversity is increasing our understanding of population structures and of how these affect host?pathogen relationships. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Computed

2005-10-20 | E-GEOD-3479 | biostudies-arrayexpress

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Project description:Helicobacter pylori bacterial populations

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Helicobacter Pylori Genome Project (HpGP)

Project description:Helicobacter pylori is a common bacterial infection. It can lead to severe stomach problems, including stomach cancer. Researchers want to look at samples of the bacteria. These H. pylori strains will be taken from chronically infected people. They want to identify the genetic and epigenetic differences in H. pylori strains. This could help predict which people who get infected with the bacteria will get stomach cancer. This could lead to the cancer being detected earlier. It could also mean less people get stomach cancer. Objectives: To study genetic variations of H. pylori strains based on samples from chronically infected people. To identify the features of strains that might lead to severe stomach problems or stomach cancer. Eligibility: People ages 30-70 years who need an upper endoscopy or who were recently diagnosed with stomach cancer Design: Participants will be screened by the doctor who does their procedure and a study nurse. Participants who have endoscopy will have ~6 biopsies removed. These are tissue samples. They are about the size of a grain of rice. Participants will allow the study team to access reports from their stomach exam. Participants with stomach cancer will donate some of the tissue that will be removed during their clinical care. They will allow the study team to access reports of their surgery. They will also allow them to access the microscope slides of their stomach.

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Global transcriptome analysis of macrophages during Helicobacter pylori infection

Project description:Based on preliminary data demonstrating that macrophages are critical regulators of Helicobacter pylori colonization and gastric pathology in mice, we sought to investigate how macrophages may serve as bacterial reservoirs of intracellular H. pylori.

2017-02-10 | GSE67270 | GEO

Helicobacter pylori outer membrane vesicle proteome

Project description:Gram negative bacteria release outer membrane vesicles (OMVs) as part of their natural growth. These OMVs take part in a biological functions including bacterial communication, exchange of genetic material and bacterial pathogenesis. However, the relationship between bacterial growth stage and OMV protein composition has not been explored before nor how their proteome is different to their parent bacterium. In this study, we examined the proteome of Helicobacter pylori and its OMVs from early log, late log or stationary phase of growth and found that globally, the protein content of OMVs over time is vastly different to one another as well as to their parent bacterium. OMVs purified from early log phase of growth contained the greatest number of unique proteins and a significant upregulation of virulence and pathogenic proteins. However, when compared back to their parent bacterium, OMVs from later stages of growth contained more unique proteins than those from earlier stages of growth. We show for the first time the regulation of OMV protein composition by H. pylori that is dependent on bacterial growth stage. Our results have expanded our understanding of the fundamental production of OMVs and the selective packaging of cargo in OMVs that result in specific functions.

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Natural selection has contributed to functional immune response differences between human hunter-gatherers and agriculturalists

Project description:The shift from a hunter-gatherer (HG) to an agricultural (AG) mode of subsistence is believed to have been associated with profound changes in the burden and diversity of pathogens across human populations. Yet, the extent to which the advent of agriculture impacted the evolution of the human immune system remains unknown. Here we present a comparative study of variation in the transcriptional responses of peripheral blood mononuclear cells (PBMCs) to bacterial and viral stimuli between the Batwa, a rainforest hunter-gatherer, and the Bakiga, an agriculturalist population from Central Africa. We observed increased divergence between hunter-gatherers and farmers in the transcriptional response to viruses compared to that for bacterial stimuli. We demonstrate that a significant fraction of these transcriptional differences are under genetic control, and we show that positive natural selection has helped to shape population differences in immune regulation. Unexpectedly, we found stronger signatures of recent natural selection in the rainforest hunter-gatherers, which argues against the popularized notion that shifts in pathogen exposure due to the advent of agriculture imposed radically heightened selective pressures in agriculturalist populations.

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Transcriptome of Helicobacter pylori in presence or absence of the cagPAI

Project description:To investigate the impact of the cagPAI on transcript regulation of H. pylori, RNA-seq was performed on bacterial samples with presence or absence of the cagPAI.

2023-04-21 | GSE227450 | GEO

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Project description:H. pilory diversity in human

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2001-07-25 | E-GEOD-6 | biostudies-arrayexpress