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Pathogenicity island mediates Helicobacter pylori interaction with the host
R Rappuoli1, C Lange, S Censini
1IRIS, Chiron S.p.A., Siena, Italy. Rappuoli@IRIS02.Biocine.IT
Folia Microbiologica
|August 26, 1998
Summary
Certain Helicobacter pylori strains possess a cag pathogenicity island (PAI), enhancing virulence and linking to ulcers and cancer. Researchers are investigating toxic factors exported by this PAI.
Area of Science:
- Microbiology
- Molecular Biology
- Pathogenesis
Background:
- Helicobacter pylori is a bacterium associated with gastric diseases.
- A subset of H. pylori strains contains a pathogenicity island (PAI) known as cag.
- Strains with the cag PAI exhibit increased virulence and are linked to peptic ulcers and gastric cancer.
Purpose of the Study:
- To investigate the role of the cag pathogenicity island (PAI) in H. pylori virulence.
- To identify potential toxic factors exported by the cag PAI.
- To understand the mechanisms underlying H. pylori-induced gastric inflammation and cellular changes.
Main Methods:
- Genomic analysis to identify the cag PAI.
- Comparative studies of virulent and non-virulent H. pylori strains.
- Investigating the function of genes encoded within the cag PAI, focusing on a putative secretory mechanism.
Main Results:
- The cag PAI is approximately 40 kb in size and present in a subset of H. pylori strains.
- Presence of the cag PAI correlates with higher bacterial virulence.
- The cag PAI encodes a putative secretory system implicated in inducing interleukin-8 (IL-8) and tyrosine phosphorylation in gastric cells.
Conclusions:
- The cag PAI is a key determinant of H. pylori virulence.
- The cag PAI's secretory system likely contributes to gastric pathogenesis by modulating host cell responses.
- Further research is needed to fully elucidate the toxic factors exported by the cag PAI and their precise roles in disease.