Helicobacter


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Helicobacter

A genus of gram-negative bacilli whose members are spiral shaped, showing corkscrewlike motility generated by multiple, usually polar flagella. Helicobacter species require low concentrations of oxygen for maximum growth and produce the enzymes oxidase, catalase, and urease.

Different species of Helicobacter are found in the stomachs of different animals: H. felis in cats and dogs, H. mustelae in the domestic ferret, H. nemestrinae in the pigtailed macaque, and H. acinonyx in captive cheetahs with gastritis. Helicobacter pylori, found in the human stomach, is extremely common. In the United States and similarly developed countries, its prevalence increases at about 1% per year of age so that the majority of adults above age 50 are infected. In less developed countries, infection rates are dramatically higher, with up to 80% of children infected.

Helicobacter pylori is present in virtually all cases of chronic gastritis, which progresses slowly (years or decades) from asymptomatic to atrophic gastritis with impaired acid secretion. Virtually all individuals with duodenal ulcers are infected with H. pylori, which colonizes sites in the duodenum. The termination of treatment for duodenal ulcers leads to a high rate of recurrence of the ulcers, but ulcer treatment plus eradication of H. pylori from the stomach usually leads to a permanent cure. A significant proportion of individuals with H. pylori-associated atrophic gastritis develop intestinal-cell metaplasia in the stomach, a condition which is known to represent a precancerous state.

Helicobacter pylori virulence factors include its shape and its ability to rapidly move into and through the gastric mucous coating, which protects the organism from stomach acid; its surface-associated urease enzyme which neutralizes stomach acid near the organism; a cytotoxin; and a fibrillar adhesin which binds the organism to the surface of gastric epithelial cells. Helicobacter pylori can survive in large numbers in spite of antibodies which are secreted into the stomach and the host immune cell response (inflammatory response) characteristic of gastritis.

References in periodicals archive ?
Isolation of Helicobacter pylori from the intestinal mucosa of patients with Crohn's disease [abstract].
Prognostic value of Helicobacter pylori sinonasal colonization for efficacy of endoscopic sinus surgery.
pdf for further information on Pariet/Aciphex, currently approved dosage and administration for Pariet as an adjunctive therapy for Helicobacter Pylori eradication, and an outline of the triple formulation pack.
Molecular characterization of the 128-kDa immunodominant antigen of Helicobacter pylori associated with cytotoxicity and duodenal ulcer.
Risk factors for Helicobacter pylori infection in children: is education a main determinant?
Prevalence of Helicobacter pylori infection, chronic gastritis, and intestinal metaplasia in Mozambican dyspeptic patients.
In partnering with Axcan for the Pylera 3-in-1 capsule therapy for Helicobacter pylori eradication, NewBridge Pharmaceuticals advances further to become one of the key providers of innovative pharmaceutical care to the Middle East, Turkey, CIS and Africa," said Dr.
Main outcome: The primary objective was to test the hypothesis that the antioxidant astaxanthin at two doses regimens compared to placebo should ameliorate gastrointestinal discomfort measured as GSRS in patients with functional dyspepsia, who were either positive or negative for Helicobacter pylori, after 4 weeks of treatment.
To the Editor: Helicobacter pylori infection is the principal cause of chronic active gastritis and peptic ulcer disease and a major contributor for gastric adenocarcinoma and mucosa-associated lymphoid tissue lymphoma
A new Helicobacter pylori vacuolating cytotoxin determinant, the intermediate region is associated with gastric cancer.
Other studies have shown that new cases of Helicobacter pylori tend to pop up in connection with various diarrhoea illnesses, and this pointed the research team in the right direction.