title: Time trends of Helicobacter pylori resistance to antibiotics in children living in Vienna, Austria.
abstract: BACKGROUND
  Increase of antibiotic resistance is a worldwide problem. Within the 4 years before the turn of the millennium Helicobacter pylori strains isolated in children living in Vienna, Austria, showed a primary clarithromycin and metronidazole resistance of 20% and 16%, respectively. The aim of this retrospective follow-up survey was to assess the further development and current antimicrobial resistance status.
  
  
  METHODS
  Children having undergone upper endoscopy between March 2002 and March 2008 at the same two co-operating pediatric gastroenterology units which had also been collaborating on the prior assessment were included. H. pylori infection was diagnosed by rapid urease test, histology, and culture. If the latter was positive, susceptibility testing to amoxicillin, clarithromycin and metronidazole by E-test followed. From March 2004 onwards, susceptibility to levofloxacin, tetracycline and rifampin was additionally assessed.
  
  
  RESULTS
  Out of 897 children, 153 had a proven infection with H. pylori and no history of prior eradication treatment. Their median age was 11.5 years (range 0.5-20.9 years). Primary resistance to clarithromycin and metronidazole were 34% and 22.9%, respectively; dual resistance was found in 9.8% of the strains; 0.9% was resistant to tetracycline and rifampin, respectively. No case of amoxicillin resistance was detected. The only independent risk factor for clarithromycin resistance turned out to be the origin of a child from Austrian parents.
  
  
  CONCLUSIONS
  In the last decade, the rate of primary resistance of H. pylori to clarithromycin continued to rise. No significant change was found regarding primary resistance to metronidazole or dual resistance to metronidazole and clarithromycin, respectively.
authors.affiliation: St. Anna Children's Hospital, Vienna, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Vécsei
authors.forename: Andrea
authors.initials: A
authors.lastname: Kipet
authors.forename: Albina
authors.initials: A
authors.lastname: Innerhofer
authors.forename: Ulrike
authors.initials: U
authors.lastname: Graf
authors.forename: Christa
authors.initials: C
authors.lastname: Binder
authors.forename: Heidemarie
authors.initials: H
authors.lastname: Gizci
authors.forename: Karin
authors.initials: K
authors.lastname: Hammer
authors.forename: Andrea
authors.initials: A
authors.lastname: Bruckdorfer
authors.forename: Wolf-Dietrich
authors.initials: WD
authors.lastname: Huber
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Hirschl
authors.forename: Athanasios
authors.initials: A
authors.lastname: Makristathis
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001317:Austria; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D005260:Female; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000302:isolation & purification; D006776:Hospitals, Pediatric; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents