The aim of the study was to evaluate the prevalence of resistance to amoxicillin, metronidazole, and clarithromycin before treatment of Helicobacter pylori infection in children and to assess the evolution of resistance with time. The study was carried out between 1994 and 1999 with 150 H. pylori-positive children through gastric culture (antimicrobial susceptibility) and histology. All cultured H. pylori strains were sensitive to amoxicillin, 64 (43%) were resistant to metronidazole, 32 (21%) were resistant to clarithromycin, and 14 (9%) were resistant to both metronidazole and clarithromycin. The overall prevalence of resistance to metronidazole and clarithromycin did not change significantly with time. The study highlights the generalized high-level and stable metronidazole and clarithromycin resistance of H. pylori strains from children.The role of Helicobacter pylori in the colonization of the stomach in adults and children with chronic gastritis, peptic ulcer, and possibly gastric carcinoma is now documented (16). Eradication of the bacterium has a great effect on prevention of peptic ulcer relapses in both adults (9) and children (23; N. Kalach, J. Raymond, P. H. Benhamou, M. Bergeret, and C. Dupont, Letter, Clin. Microbiol. Infect. 5:235-236, 1999).The great jump in the understanding of the diseases mentioned above was accompanied by progressive evidence of the antibiotic resistance phenomenon, first reported for clarithromycin (21), a macrolide that partially carries crossover resistance to other antibiotics belonging to the same class (6). Resistance now involves antibiotics previously devoid of any resistance issues for that bacterium, such as amoxicillin, to which resistance sometimes occurs at a high level (4), largely challenging physicians at the present time (8). One important point is that antibiotic treatment of H. pylori involves drugs largely in use for other kinds of infections. For that reason, analysis of the resistance phenomenon must probably take into account a half century of coexistence between antibiotic habits and this parasitic bacterium, emphasizing the importance of analyzing both geographical variations and evolution with time (7).The purpose of our study was to evaluate the prevalence of resistance to amoxicillin, metronidazole, and clarithromycin before treatment of H. pylori infection in children and to assess the evolution of resistance with time compared to those from reference studies with both adults and children.A prospective study was carried out from January 1994 to July 1999 with 150 H. pylori-positive children (76 girls and 74 boys) aged 11.25 Ϯ 3.9 years (mean Ϯ 1 standard deviation [SD]; range, 1.75 to 18 years). Infection was proved by upper gastrointestinal endoscopy for retrieval of gastric antral biopsy specimens in the course of diagnostic evaluation of clinical gastritis, manifested by recurrent abdominal pain for at least 3 months, nausea, and vomiting. Informed consent from the parents was obtained. Children who had already suffered gastric H. pylori infect...
