title: Increasing metronidazole and rifampicin resistance of Helicobacter pylori isolates obtained from children and adolescents between 2002 and 2015 in southwest Germany.
abstract: BACKGROUND
  Increasing antibiotic resistance has been reported for Helicobacter pylori, but data on the prevalence of antibiotic resistance of H. pylori in pediatric patients and the development of resistance over time are sparse.
  
  
  METHODS
  Data for 610 H. pylori isolates obtained between 2002 and 2015 from gastric biopsies of 582 (mainly treatment-naïve) pediatric patients from southwest Germany were analyzed retrospectively regarding the antibiotic susceptibility determined by Etest and patients' characteristics.
  
  
  RESULTS
  Overall resistance to metronidazole, clarithromycin, and rifampicin was 28.7%, 23.2%, and 13.3%, respectively, while resistance to amoxicillin was rare (0.8%). Simultaneous resistance to metronidazole and clarithromycin was observed for 7.7% of the isolates, and 2.3% were resistant to metronidazole, clarithromycin, and rifampicin. Differences between primary vs secondary resistance existed for metronidazole (24.7% vs 38.8%, P=.01) and clarithromycin (17.2% vs 54.1%, P=.0001). From 2002-2008 to 2009-2015, resistance to metronidazole increased from 20.8% to 34.4% (P=.003) and to rifampicin from 3.9% to 18.8% (P=.0001); this was not associated with increased numbers of patients previously treated for H. pylori infection in the second study period. In contrast, resistance to clarithromycin did not change significantly over time. Resistance was not associated with age, sex, or family origin in Europe.
  
  
  CONCLUSIONS
  The considerable antibiotic resistance of H. pylori isolates argues for standard antibiotic susceptibility testing of H. pylori in pediatric patients prior to the initiation of antibiotic therapy.
authors.affiliation: Laboratory Enders & Partners, Stuttgart, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Regnath
authors.affiliation: Children's Hospital, Pediatric Gastroenterology, Klinikum Esslingen, Esslingen, Germany.
authors.forename: Olaf
authors.initials: O
authors.lastname: Raecke
authors.affiliation: Center for Pediatric Medicine, Olgahospital, Stuttgart, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Enninger
authors.affiliation: Laboratory Enders & Partners, Stuttgart, Germany.|Department of Microbiology and Hygiene, Charité, Berlin, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Ignatius
mesh_terms: D000293:Adolescent; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D005260:Female; D005858:Germany / Q000453:epidemiology; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000382:microbiology*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D008297:Male; D008795:Metronidazole / Q000494:pharmacology*; D015995:Prevalence; D012189:Retrospective Studies; D012293:Rifampin / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D008795:Metronidazole; D012293:Rifampin
keywords: 
  Helicobacter pylori
  ; adolescents; antimicrobial resistance; children; southwest Germany