The importance of CagA protein in Helicobacter Pylori infection

1 Junior Investigator, MSc Candidate, Faculty of Science, Microbiology Department, Universidad Javeriana 2 Professor of Microbiology, Medical Microbiology Specialization Director, PhD Candidate, Universidad Javeriana, Faculty of Science, Department of Microbiology 3 Internist, Gastroenterologist, Epidemiologist, Professor of Medicine, Gastroenterology Unit, National University of Colombia. ........................................ Received: 25-05-09 Accepted: 14-10-09 Summary Helicobacter pylori is a microorganism able to colonize gastric mucosa in humans where it can produce chronic gastritis and other type of complications. H. pylori is present approximately 20-50% in the industrialized countries but in developing countries its prevalence is the highest because approximately 80% of people are infected with the bacteria. In general this bacteria is variable in its genome but the greatest genetic plasticity is located at 40kb DNA segment, knowing as a pathogenicity island (PAI), inside of this DNA segment there are cagA gen which coding for CagA protein and genes that coding for type IV secretion system that is necessary for export CagA protein into target cell. cagA gen is important because it is a marker of PAI presence and because the presence of cagA has permitted classifi ed H. pylori strains in cagA+ and cagA-, which is of great importance due cagA+ strains are more virulent than cagAstrains, although the principal importance of cagA + strains is its special association with gastric cancer. The aim of this review is study the functions of pathogenicity island genes and its association with gastro duodenal pathologies developing.