Antimicrobial susceptibility of Helicobacter pylori strains in a random adult Swedish population

Background and Aim: Antimicrobial resistance in Helicobacter pylori is a growing problem and has become an important factor leading to eradication failure. Information on antimicrobial susceptibility is important for selection of an optimum treatment regimen. The resistance rate in a random population has not been studied previously. Methods: A random Swedish population sample (n = 3000, age 20-81 years) was surveyed using a mailed validated questionnaire assessing gastrointestinal symptoms (response rate of 74%). One-third of the responders was invited, in random order, and accepted an esophagogastroduodenoscopy with biopsies for H. pylori culture and histology. Subjects were not treated for their H. pylori infection but a minimum inhibitory concentration of metronidazole, clarithromycin, amoxicillin, and tetracycline for the H. pylori isolates (n = 333) was determined by agar dilution. Prescribed antibiotic in the area was recorded. Results: Irrespective of symptomatology, 16.2% of the isolated H. pylori strains were resistant to metronidazole, 1.5% to clarithromycin, 0% to amoxicillin, and 0.3% to tetracycline. The antibiotic consumption was low from an international perspective. Conclusion: The resistance to the antibiotics was lower than expected from patient sample studies, especially for clarithromycin, most probably due to a restrictive prescription policy in the area. Introduction of a test-and-treat strategy in Sweden would only marginally affect the usage of clarithromycin.