Primary and secondary antibiotic resistance of Helicobacter pylori in Israeli children and adolescents

Background: Empiric treatment for Helicobacter pylori is influenced by antibiotic susceptibility of infecting strains. A rise in the resistance rate to clarithromycin and metronidazole has been reported in pediatric populations. Objectives: To assess the primary and secondary antibiotic resistance of H. pylori isolates in Israeli children and adolescents. Methods: A retrospective review of H. pylori isolates cultured from antral biopsies of consecutive children aged 1 to 18 years, who were referred to the Pediatric Gastroenterology Unit, Kaplan Medical Center, over a 2.8 year period, was performed. Antibiotic susceptibility to clarithromycin, metronidazole, amoxicillin, tetracycline, and levofloxacin was determined by E-test. Data on the age of the patient, indication for endoscopy, and antibiotic treatment for H. pylori in previously treated children was collected. Results: Cultures for H. pylori yielded 123 isolates. In children not previously treated (n=95), the primary global resistance was 38% with resistance to clarithromycin 9.5%, metronidazole 32.6 %, and to both 4.2%. Respective rates of resistance in previously treated children (n=28) were 71% (P = 0.002), 29% (P = 0.02), and 61% (P = 0.007). Simultaneous resistance to both drugs was found in 18% (P = 0.02). All H. pylori strains were susceptible to amoxicillin, tetracycline, and levofloxacin. Past eradication treatment was the only independent risk factor for antibiotic resistance in multivariate analysis. Conclusions: Significantly higher resistance rates were found in previously treated patients, stressing the need to refrain from empiric treatment using the "test and treat strategy." Culture-based treatment strategy should be considered in all previously treated children.