Prevalence of Helicobacter pylori resistant to clarithromycin, metronidazole and amoxicillin isolated from pediatric patients in China

Background: Antimicrobial resistance in Helicobacter pylori (H. pylori) is an increasing serious problem, and the development of methods for detecting the resistance and the constant surveillance of both prevalence and evolution of H. pylori resistance in children would greatly improve the selection of antibiotics used to treat gastroduodenal infection with this organism. This study was designed to investigate the prevalence of H. pylori resistance to clarithromycin, metronidazole and amoxicillin isolated from pediatric patients in China. Methods: A total of 44 H. pylori isolates from pediatric patients with gastritis and peptic ulcer undergoing endoscopy were cultured during the period of October 2002 to November 2003 at Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China. The susceptibilities of the 44 H. pylori isolated strains to clarithromycin, metronidazole and amoxicillin were tested by the agar dilution test to determine the minimum inhibitory concentration (MIC). Results: The range of MIC was as follows: clarithromycin 0.125-64 μg/ml; metronidazole <0.125-128 μg/ml; and amoxicillin <0.125-64 μg/ml. The rate of H. pylori resistant to clarithromycin, metronidazole and amoxicillin in the children was 18.2% (8 strains), 31.8% (14 strains) and 9.1% (4 strains), respectively. Three strains (6.8%) were simultaneously resistant to the 3 antibiotics. Conclusions: The prevalence of H. pylori resistance to metronidazole is high in children, and the rate of resistance to clarithromycin is higher than that in adults. Amoxicillin-resistant strains are found, and multidrug-resistant strains of H. pylori to clarithromycin, metronidazole and amoxicillin are also found. World J Pediatr 2006;1:49-52