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.