Genetic fine structure analysis of Helicobacter pylori isolates before and after treatment.

BACKGROUND

Eradication of H. pylori infection cures peptic ulcer disease and conversely, relapse is associated with reappearance of H. pylori infection. However, it is not clear whether the recurrence of ulcers following H. pylori eradication is due to recrudescence (identical strain) of the previous infection or as a result of exogenous reinfection (different strain) by another strain. The aim of the present study was to analyze the FAFLP patterns of pre and post treatment H. pylori samples to check if the recurrence was due to recrudescence or reinfection.

MATERIALS AND

METHODS

24 of 30 duodenal ulcer (DU) subjects screened for H. pylori infection were positive for H. pylori infection. The treatment regime included pantoprazole, ciprofloxacin and amoxicillin. The patients were called for a repeat endoscopy after one month and screened for H. pylori infection. FAFLP analysis and PCR for the cagA and vacA gene was performed for the pre and post treatment samples.

RESULTS

Of the 24 positive H. pylori patients, only 6 were negative after treatment and the remaining 18 were positive for H. pylori infection. The analysis of the pre and post treatment samples of the 18 patients showed that the FAFLP profiles of the initial and follow-up pools were similar to one another.

CONCLUSION

It can be concluded that in the present series of patients, reinfection was due to recrudescence of infection due to incomplete eradication. The study also suggests that DNA fingerprinting by FAFLP provides discriminatory and complementary data for identifying strains of H. pylori while monitoring therapy.