Analysis Of The Infectious Character And Typing The CagA And VacA Gene And Testing Macrolides Susceptibility Of Helicobacter Pylori Clinical Isolates In Xi'an Area

Helicobacter pylori is an important human pathogen that causes chronic gastritis and is associated with the development of peptic ulcer diseases, atrophic gastritis, and gastric malignancies. Epidemiological studies on large series show that Helicobacter pylori is a group I carcinogen for gastric carcinoma,which is one of the most frequent cancers worldwide.Helicobacter pylori is a gram — negative spiral bacterium that colonizes the gastric mucosa and is able to persist over decades it the infection is not treated. The chronic infection often occurs without symptoms, but some individuals develop severe features of upper gastrointestinal diseases such as peptic ulcer disease, gastric adenocarcinoma, and MALT lym-phoma. The mechanisms whereby H. pylori exerts its pathogenetic action are not yet well understood. The several virulence factors such as motility,adhesion to the gastric epithelium,urease activity can't explain them.The genetic variability among H. pylori strains is relatively high. Re-...