Antibiotic-Resistant Helicobacter pylori Strains in Portuguese Children

Abstract

Data concerning the effectiveness of Helicobacter pylori eradication regimens based in antibiotic susceptibility testing are scanty in children. To identify the prevalence of antibiotic resistance in H. pylori strains isolated from Portuguese children in 1999-2003; to evaluate eradication rate after antibiotic susceptibility testing-based treatment; and to identify factors associated with resistance and eradication outcome. Included were 109 children with a gastric biopsy culture positive for H. pylori. First treatment (amoxicillin, omeprazole and clarithromycin or metronidazole) was guided by susceptibility testing (E test), and eradication was assessed by [C]urea breath test. Strains were susceptible to amoxicillin and tetracycline; 39.4% were resistant to clarithromycin, 16.5% to metronidazole and 4.5% to ciprofloxacin. No significant association was found between resistance and sex, age, clinical status, gastritis scores, H. pylori density scores and genotype. Clarithromycin resistance was significantly associated with European origin [odds ratio (OR), 3.9], previous H. pylori empiric therapy (OR 2.8) and amoxicillin minimal inhibitory concentration, > or =0.016 (OR 6.0). Eradication rate after susceptibility-based treatment was 74.7% (59 of 79; 95% confidence interval, 65.9-82.9), and a significant association was found between eradication failure and presence of resistance to 1 or more antibiotics (P < 0.05). The prevalence of H. pylori antibiotic resistance was high in the studied population. The modest therapeutic success of clarithromycin and metronidazole susceptibility-based regimens suggests that in addition to resistance, other factors may be involved. The need of susceptibility-based treatment studies in children and of antimicrobial resistance surveillance in high prevalence areas for H. pylori are emphasized.