The Human Stomach in Health and Disease: Infection Strategies by Helicobacter pylori

2017 ◽  
pp. 1-26 ◽  
Author(s):  
Karen Robinson ◽  
Darren P. Letley ◽  
Kazuyo Kaneko
Keyword(s):  
Helicobacter Pylori ◽  
Human Stomach ◽  
Health And Disease

Helicobacter pylori infection induces a decrease in immunoreactive-somatostatin concentrations of human stomach

1992 ◽  
Vol 37 (3) ◽  
pp. 409-416 ◽  
Author(s):  
Hiroshi Kaneko ◽  
Koichi Nakada ◽  
Terunori Mitsuma ◽  
Kiyoshi Uchida ◽  
Atsushi Furusawa ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Human Stomach ◽  
Helicobacter Pylori Infection

Effect of Helicobacter pylori Infection on the Activity of Class I, III and IV Alcohol Dehydrogenase in the Human Stomach

Digestion ◽  
2002 ◽  
Vol 66 (1) ◽  
pp. 14-18 ◽  
Author(s):  
L. Chrostek ◽  
W. Jelski ◽  
M. Szmitkowski ◽  
W. Laszewicz
Keyword(s):  
Helicobacter Pylori ◽  
Alcohol Dehydrogenase ◽  
Human Stomach ◽  
Class I

scholarly journals Mutational Analysis of Metronidazole Resistance in Helicobacter pylori

2005 ◽  
Vol 49 (3) ◽  
pp. 1236-1237 ◽  
Author(s):  
Jill M. Moore ◽  
Nina R. Salama
Keyword(s):  
Helicobacter Pylori ◽  
Mutational Analysis ◽  
Transposon Mutagenesis ◽  
Human Stomach ◽  
Metronidazole Resistance ◽  
H Pylori ◽  
Chromosomal Loci

ABSTRACT Metronidazole is one of a few antibiotics effective in eliminating Helicobacter pylori infection of the human stomach. Several chromosomal loci have been implicated in resistance to this drug. Saturation transposon mutagenesis of the H. pylori genome revealed inactivation of the rdxA gene as uniquely able to confer metronidazole resistance.

Acid Acclimation byHelicobacter pylori

Physiology ◽  
2005 ◽  
Vol 20 (6) ◽  
pp. 429-438 ◽  
Author(s):  
George Sachs ◽  
David L. Weeks ◽  
Yi Wen ◽  
Elizabeth A. Marcus ◽  
David R. Scott ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Carbonic Anhydrase ◽  
Human Stomach ◽  
Peptic Ulcers ◽  
Acidic Media ◽  
Gram Negative ◽  
Urea Channel ◽  
Acid Acclimation ◽  
Unique Ability

Helicobacter pylori is a Gram-negative neutralophile associated with peptic ulcers and gastric cancer. It has a unique ability to colonize the human stomach by acid acclimation. It uses the pH-gated urea channel, UreI, to enhance urea access to intrabacterial urease and a membrane-anchored periplasmic carbonic anhydrase to regulate periplasmic pH to ~6.1 in acidic media, whereas other neutralophiles cannot regulate periplasmic pH and thus only transit the stomach.

scholarly journals Helicobacter pylori is killed by nitrite under acidic conditions

Gut ◽  
1998 ◽  
Vol 42 (3) ◽  
pp. 334-337 ◽  
Author(s):  
R S Dykhuizen ◽  
A Fraser ◽  
H McKenzie ◽  
M Golden ◽  
C Leifert ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Anaerobic Bacteria ◽  
Antimicrobial Effect ◽  
Human Stomach ◽  
Bacterial Survival ◽  
Novel Host ◽  
Potassium Nitrite ◽  
Acidic Conditions ◽  
H Pylori ◽  
Facultative Anaerobic Bacteria

Background—Due to the expression of urease,Helicobacter pylori is able to establish itself in the human stomach under acidic conditions. A novel host defence mechanism was recently proposed, suggesting that the formation of salivary nitrite in symbiosis with facultative anaerobic bacteria in the oropharynx, is aimed at enhancing the antimicrobial activity of gastric juice.Aims—To investigate whether the addition of nitrite in physiological concentrations influences the resistance ofH pylori to acid.Methods—H pylori cultured from fresh gastric biopsy specimens was exposed for 30 minutes to normal saline and to HCl/KCl buffer (0.2M) at pH 2 with urea (5 mM) added. The influence of potassium nitrite (50–1000 μmol/l) on bacterial survival was determined.Results—Addition of nitrite (1 mM) to acidic solutions (pH 2) resulted in complete kill of H pyloriwithin 30 minutes exposure time whereas acid alone allowed the organism to survive (p<0.001). The antimicrobial effect of nitrite at pH 2 against H pylori was dose dependent and complete kill of organisms occurred at concentrations ⩾500 μmol/l.Conclusion—Acidified nitrite has antibacterial activity against H pylori. This should prompt further research into the effect of salivary nitrite on the survival of H pylori in the human stomach.

scholarly journals Helicobacter pylori–binding nonacid glycosphingolipids in the human stomach

2018 ◽  
Vol 293 (44) ◽  
pp. 17248-17266 ◽  
Author(s):  
Chunsheng Jin ◽  
Angela Barone ◽  
Thomas Borén ◽  
Susann Teneberg
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Structural Complexity ◽  
Human Stomach ◽  
Carbohydrate Binding ◽  
Human Gastric Mucosa ◽  
H Pylori ◽  
Contrast Information

Helicobacter pylori has a number of well-characterized carbohydrate-binding adhesins (BabA, SabA, and LabA) that promote adhesion to the gastric mucosa. In contrast, information on the glycoconjugates present in the human stomach remains unavailable. Here, we used MS and binding of carbohydrate-recognizing ligands to characterize the glycosphingolipids of three human stomachs from individuals with different blood group phenotypes (O(Rh−)P, A(Rh+)P, and A(Rh+)p), focusing on compounds recognized by H. pylori. We observed a high degree of structural complexity, and the composition of glycosphingolipids differed among individuals with different blood groups. The type 2 chain was the dominating core chain of the complex glycosphingolipids in the human stomach, in contrast to the complex glycosphingolipids in the human small intestine, which have mainly a type 1 core. H. pylori did not bind to the O(Rh−)P stomach glycosphingolipids, whose major complex glycosphingolipids were neolactotetraosylceramide, the Lex, Lea, and H type 2 pentaosylceramides, and the Ley hexaosylceramide. Several H. pylori-binding compounds were present among the A(Rh+)P and A(Rh+)p stomach glycosphingolipids. Ligands for BabA-mediated binding of H. pylori were the Leb hexaosylceramide, the H type 1 pentaosylceramide, and the A type 1/ALeb heptaosylceramide. Additional H. pylori-binding glycosphingolipids recognized by BabA-deficient strains were lactosylceramide, lactotetraosylceramide, the x2 pentaosylceramide, and neolactohexaosylceramide. Our characterization of human gastric receptors required for H. pylori adhesion provides a basis for the development of specific compounds that inhibit the binding of this bacterium to the human gastric mucosa.

Helicobacter pylori and the Surface Mucous Gel Layer of the Human Stomach

Helicobacter ◽  
1996 ◽  
Vol 1 (4) ◽  
pp. 207-218 ◽  
Author(s):  
Toshiki Shimizu ◽  
Taiji Akamatsu ◽  
Atsushi Sugiyama ◽  
Hiroyoshi Ota ◽  
Tsutomu Katsuyama
Keyword(s):  
Helicobacter Pylori ◽  
Human Stomach ◽  
Gel Layer

scholarly journals Helicobacter pylori Accumulates Photoactive Porphyrins and Is Killed by Visible Light

2005 ◽  
Vol 49 (7) ◽  
pp. 2822-2827 ◽  
Author(s):  
Michael R. Hamblin ◽  
Jennifer Viveiros ◽  
Changming Yang ◽  
Atosa Ahmadi ◽  
Robert A. Ganz ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Visible Light ◽  
Propionibacterium Acnes ◽  
Protoporphyrin Ix ◽  
Human Stomach ◽  
Drug Resistant ◽  
Violet Light ◽  
Resistant Strains ◽  
H Pylori ◽  
Drug Resistant Strains

ABSTRACT Helicobacter pylori colonizes the mucus layer of the human stomach and duodenum, causes chronic gastritis, gastric ulcer, and is a risk factor for gastric adenocarcinoma. There is a 20% failure rate in antibiotic therapy, which is increasingly due to antibiotic resistance and necessitates the search for alternative antimicrobial methods. We have discovered that H. pylori when cultured in liquid medium, accumulates significant quantities of coproporphyrin and protoporphyrin IX, both in the cells and secreted into the medium. These photoactive porphyrins lead to cell death (up to 5 logs) by photodynamic action upon illumination with low doses of visible light, with blue/violet light being most efficient. The degree of killing increases with the age of the culture and is greater than that found with Propionibacterium acnes (another bacterium known to be photosensitive due to porphyrin accumulation). Both virulent and drug-resistant strains are killed. The data suggest that phototherapy might be used to treat H. pylori infection in the human stomach.

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