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Acid-regulated gene expression of Helicobacter pylori: Insight into acid protection and gastric colonization
- Source :
- Helicobacter. 23(3)
- Publication Year :
- 2018
-
Abstract
- Background The pathogen Helicobacter pylori encounters many stressors as it transits to and infects the gastric epithelium. Gastric acidity is the predominate stressor encountered by the bacterium during initial infection and establishment of persistent infection. H. pylori initiates a rapid response to acid to maintain intracellular pH and proton motive force appropriate for a neutralophile. However, acid sensing by H. pylori may also serve as a transcriptional trigger to increase the levels of other pathogenic factors needed to subvert host defenses such as acid acclimation, antioxidants, flagellar synthesis and assembly, and CagA secretion. Materials and methods Helicobacter pylori were acid challenged at pH 3.0, 4.5, 6.0 vs nonacidic pH for 4 hours in the presence of urea, followed by RNA-seq analysis and qPCR. Cytoplasmic pH was monitored under the same conditions. Results About 250 genes were induced, and an equal number were repressed at acidic pHs. Genes encoding for antioxidant proteins, flagellar structural proteins, particularly class 2 genes, T4SS/Cag-PAI, Fo F1 -ATPase, and proteins involved in acid acclimation were highly expressed at acidic pH. Cytoplasmic pH decreased from 7.8 at pHout of 8.0 to 6.0 at pHout of 3.0. Conclusions These results suggest that increasing extracellular or intracellular acidity or both are detected by the bacterium and serve as a signal to initiate increased production of protective and pathogenic factors needed to counter host defenses for persistent infection. These changes are dependent on degree of acidity and time of acid exposure, triggering a coordinated response to the environment required for colonization.
- Subjects :
- 0301 basic medicine
Proteome
Virulence Factors
Intracellular pH
030106 microbiology
Article
Microbiology
03 medical and health sciences
Bacterial Proteins
Gene expression
Extracellular
CagA
Secretion
Pathogen
biology
Helicobacter pylori
Chemistry
Stomach
Gastroenterology
General Medicine
Gene Expression Regulation, Bacterial
Hydrogen-Ion Concentration
biology.organism_classification
Adaptation, Physiological
Urease
Culture Media
RNA, Bacterial
030104 developmental biology
Infectious Diseases
Multigene Family
Transcriptome
Acids
Intracellular
Subjects
Details
- ISSN :
- 15235378
- Volume :
- 23
- Issue :
- 3
- Database :
- OpenAIRE
- Journal :
- Helicobacter
- Accession number :
- edsair.doi.dedup.....656abd4091c86322d10fc8374783bae8