DNA-based diagnostic techniques to detect Helicobacter pylori

Background: Helicobacter pylori (H. pylori) is an important cause of many gastrointestinal disorders, ranging from chronic gastritis to gastric lymphoma and adenocarcinoma.

Aim: To summarize current techniques of H. pylori diagnosis.

Methods and results: The DNA-based assays have the potential to be a

powerful diagnostic tool given its ability to specifically identify H. pylori DNA. Markers used include general H. pylori structures and pathogenetic factors like ureaseA, cagA, vacA, IceA.

DNA or bacterial RNA for PCR assays can be collected from gastric biopsy, gastric juice, stool, buccal specimens. PCR can yield quantitative and genotyping results with sensitivity and specificity that approaches 100%. A clear trend in the direction of the determination of quantitative H. pylori infection by real-time PCR can be observed. FISH is suggested for routine antibiotic resistance determination. To identify the organism DNA structure and its virulence factors may be feasible by using oligonucleotide microarray specifically recognizing and discriminating bacterial DNA and various virulence factors.

Conclusion: DNA based H. pylori diagnosis yields higher sensitivity, however, specificity requires sophisticated labour environment and associated with higher costs.