Helicobacter pylori-Clarithromycin Resistance in Symptomatic Pediatric Patients in a High Prevalence Country

Serrano, Carolina A.; Leon, Miguel A.; Palma, Camila; Vera, Macarena; Hernandez, Caroll; Harris, Paul R.

Journal of Pediatric Gastroenterology & Nutrition: March 2017 - Volume 64 - Issue 3 - p e56–e60
doi: 10.1097/MPG.0000000000001257
Original Article: Gastroenterology

Introduction: Failure to eradicate Helicobacter pylori despite antibiotic treatment is generally attributed to increasing clarithromycin resistance conferred by point mutations in the 23S-rRNA gene or metronidazole resistance attributed to rdxA gene (HP0954) deletion in patients. Scarce data for pediatric population are available from developing countries.

Objectives: The aim of the present study was to determine the presence of A2142G/C and A2143G mutations in the 23S-rRNA gene and/or rdxA gene (HP0954) deletion in a group of symptomatic H pylori–infected children recruited from an area with high infection rate and risk of gastric cancer.

Patients and Methods: We recruited 118 patients referred for upper endoscopy for gastrointestinal symptoms. The presence of H pylori was determined by urease test and histological staining. The rdxA gene (HP0954) deletion, and 2142G/C and A2143G mutations were determined by polymerase chain reaction–restriction fragment length polymorphism. A subgroup of infected patients received a 14-day regimen of omeprazole, amoxicillin, and clarithromycin. The effectiveness of this regime was determined by stool antigen determination 8 weeks after treatment.

Results: About 21% of the analyzed infected patients showed mutation in the 23S-rRNA gene, with the A2143G transition as the more frequent mutation, and 2% of the patients showed rdxA gene (HP0954) deletion. After treatment, 25% of the patients continued to harbor the bacteria; of these, 67% carried the A2143G mutation.

Conclusions: H pylori–infected pediatric patients from Chile show high prevalence of the mutation responsible for clarithromycin resistance. The failure to eradicate H pylori can be attributed to the presence of the A2143G mutation.

Department of Pediatric Gastroenterology and Nutrition, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.

Address correspondence and reprint requests to Paul R. Harris, 391 Marcoleta, Centro de Investigaciones Médicas, Santiago, Chile (e-mail: pharris@med.puc.cl).

Received 19 November, 2015

Accepted 27 April, 2016

This study is supported by grant numbers 1100654 and 1130387 from Fondo Nacional De Desarrollo Científico y Tecnológico, Chile.

The authors report no conflicts of interest.

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© 2017 by European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology,