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Gastroenterology Research and Practice
Volume 2013, Article ID 356217, 5 pages
Clinical Study

Association of IS605 and cag-PAI of Helicobacter pylori Isolated from Patients with Gastrointestinal Diseases in Taiwan

1Department of Microbiology, School of Medicine, China Medical University, Taichung 40402, Taiwan
2Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, Taipei 11217, Taiwan
3School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan
4Division of Gastroenterology and Hepatology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei 11031, Taiwan
5School of Medicine, Taipei Medical University, Taipei 11031, Taiwan

Received 4 September 2012; Revised 26 December 2012; Accepted 19 January 2013

Academic Editor: Vikram Kate

Copyright © 2013 Chih-Ho Lai et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background. The cag pathogenicity island (cag-PAI) is one of the most important virulent determinants of Helicobacter pylori. An insertion sequence (IS) element of cag-PAI (IS605) has been found to generate H. pylori strains with varying virulence. Aim. To evaluate the impact of IS605 and cag-PAI on H. pylori strains isolated from Taiwanese patients with severity of gastric diseases. Methods. H. pylori isolates were cultured from gastric biopsies from 99 patients with peptic ulcer, chronic gastritis, and gastric carcinoma. Six distinct, well-separated colonies were isolated from each patient and analyzed by genotyping. Results. cagA, cagE, cagM, cagT, orf10, and orf13 were found to be present in 90.0%–100.0% of the H. pylori isolates. A total deletion of cagA, cagE, cagM, cagT, orf10, and orf13 was found in 1 isolate (1.0%). The IS605 element was found to be positive in 15.2% of the isolates. The presence of IS605 was higher in H. pylori isolated from patients with gastric carcinoma (25.0%) than in patients with duodenal ulcer (6.5%) or chronic gastritis (6.3%) ( ). Conclusions. The majority of the patients examined had intact cag-PAI. IS605 was present in 15.2% and was higher in H. pylori isolated from patients with gastric carcinoma than in those with peptic ulcer.