Identification ofHelicobacter pyloriand thecagAgenotype in gastric biopsies using highly sensitive real-time PCR as a new diagnostic tool
Open Access
- 1 June 2005
- journal article
- research article
- Published by Oxford University Press (OUP) in FEMS Immunology & Medical Microbiology
- Vol. 44 (3), 261-268
- https://doi.org/10.1016/j.femsim.2004.12.011
Abstract
The CagA protein is one of the virulence factors of Helicobacter pylori, and two major subtypes of CagA have been observed, the Western and East Asian type. CagA is injected from the bacteria into gastric epithelial cells, undergoes tyrosine phosphorylation, and binds to Src homology 2 domain-containing protein-tyrosine phosphatase SHP-2. The East Asian type CagA binds to SHP-2 more strongly than the Western type CagA. Here, we tried to distinguish the CagA type by highly sensitive real-time PCR with the objective of establishing a system to detect H. pylori and CagA subtypes from gastric biopsies. We designed primers and probe sets for Western or East Asian-cagA at Western-specific or East Asian-specific sequence regions, respectively, and H. pylori 16S rRNA. We could detect the H. pylori 16S rRNA gene, Western and East Asian-cagA gene from DNA of gastric biopsies. The sensitivity and specificity for H. pylori infection was 100% in this system. In Thai patients, 87.8% (36/41) were cagA-positive; 26.8% (11/41) were Western-cagA positive and 53.7% (22/41) were East Asian-cagA positive, while 7.3% (3/41) reacted with both types of cagA. These results suggest that this real-time PCR system provides a highly sensitive assessment of CagA type as a new diagnostic tool for the pathogenicity of H. pylori infection.Keywords
This publication has 35 references indexed in Scilit:
- Meta-analysis of the relationship between cagA seropositivity and gastric cancerGastroenterology, 2003
- Helicobacter pyloriInfection and the Development of Gastric CancerNew England Journal of Medicine, 2001
- Helicobacter pylori Virulence and Genetic GeographyScience, 1999
- Relationship of Helicobacterpylori CagA Status to Gastric Cell Proliferation and ApoptosisDigestive Diseases and Sciences, 1999
- Analyses of the cag pathogenicity island of Helicobacter pyloriMolecular Microbiology, 1998
- Helicobacter pylori cagA+ Strains and Dissociation of Gastric Epithelial Cell Proliferation From ApoptosisJNCI Journal of the National Cancer Institute, 1997
- cag , a pathogenicity island of Helicobacter pylori, encodes type I-specific and disease-associated virulence factorsProceedings of the National Academy of Sciences of the United States of America, 1996
- Helicobacter pylori and Atrophic Gastritis: Importance of the cagA StatusJNCI Journal of the National Cancer Institute, 1995
- An international association between Helicobacter pylori infection and gastric cancerThe Lancet, 1993
- Helicobacter pyloriInfection and the Risk of Gastric CarcinomaNew England Journal of Medicine, 1991