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Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Autónoma de Yucatán

2000, Number 3

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Rev Biomed 2000; 11 (3)

Helicobacter pylori: virulence factors and their relationship with the gastroduodenal pathology

Rivas-Traverso F, Hernández F

Language: Spanish
References: 148
Page: 187-205
PDF size: 123.18 Kb.


ABSTRACT

In this paper we review evidence concerning virulence factors of Helicobacter pylori, the major cause of gastritis, peptic ulcers and some kinds of gastric neoplasia. We also summarize the findings about possible modes of transmission, including the following routes: oral-oral, gastric-oral, and fecaloral. The main evidence for each of those routes is bacterial isolation and identification of DNA from saliva, dental plaque, faeces, and water. Also, virulence factors are described, such as: a) urease activity which promotes the liberation of ammonia that could induce damage on the gastric epithelia; b) bacterial adhesins that are fundamental to the colonization process; c) haemagglutinins that could induce auto-antibodies due to their biochemical similarity with some antigens fo blood groups; d) presence of vacuolization associated gene (vacA) and cytotoxin-associated gene (cagA) that correlates with highly virulent strains exhibiting toxin activity. The worlwide epidemiological profile of H. pylori correlates with the distribution of gastric cancer. We also describe the methodology for the diagnosis of H. pylori by culture, including an economic method, which generates the required microaerophilic atmosphere, a low cost rapid urease method as well as the microscopic visualization of curved bacteria from gastric biopsy tissues.


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