title: [Acquisition of secondary resistance after failure of a first treatment of Helicobacter pylori infection in children].
abstract: OBJECTIVE
  To assess the frequency of acquisition of secondary Helicobacter pylori resistant-strains after a first course of antimicrobial treatment.
  
  
  METHODS
  A retrospective study was performed during the 1994-2000 period, in 15 girls and eight boys, mean age 10.9 +/- 4.8 years (1.4-17 years), with Helicobacter pylori gastritis (culture and antimicrobial susceptibility) presenting a failure of first course treatment, with during one week a proton pump inhibitor and amoxicillin together with either clarithromycin (n = 14) or metronidazole (n = 9). Two endoscopies were performed, the first at the time of diagnosis and the second after the failure of bacterial eradication demonstrated by a positive 13C urea breath test six weeks after the end of treatment. Antimicrobial susceptibility of all Helicobacter pylori strains was tested after each endoscopy and before starting a second course of the treatment.
  
  
  RESULTS
  Comparison of antimicrobial susceptibility before and after the first course of treatment showed that Helicobacter pylori strains were all sensitive to amoxicillin, clarithromycin-resistant in eight children (34.7%) before treatment vs 12 (52.1%) after treatment, p = 0.42, ns, metronidazole-resistant in 13 (56.5%) vs 12 (52.1%), p = 0.80, ns, and both clarithromycin and metronidazole-resistant in four (17.3%) vs seven (30.4%), p = 0.63, ns. Among the 14 children treated by a triple therapy including clarithromycin, three (21.4%) developed a secondary resistance to clarithromycin and in one metronidazole resistance was no more detected. Among the nine children treated with a triple therapy including metronidazole, none developed a secondary resistance to metronidazole and one developed a secondary resistance to clarithromycin.
  
  
  CONCLUSIONS
  This study shows the absence of amoxicillin-resistant strains, a high initial clarithromycin-resistant strains level (primary resistance), increasing after a first course of treatment, and for metronidazole a high initial level of resistance not influenced by treatment. Secondary clarithromycin-resistance of Helicobacter pylori strains following the first course of treatment could account for failure of bacterial eradication and suggests the importance of antimicrobial susceptibility.
authors.affiliation: Service de pédiatrie, hôpital Saint-Vincent-de-Paul, 82, avenue Denfert-Rochereau, 75674 Paris, France.
authors.forename: N
authors.initials: N
authors.lastname: Kalach
authors.forename: P H
authors.initials: PH
authors.lastname: Benhamou
authors.forename: M
authors.initials: M
authors.lastname: Bergeret
authors.forename: F
authors.initials: F
authors.lastname: Gottrand
authors.forename: M O
authors.initials: MO
authors.lastname: Husson
authors.forename: C
authors.initials: C
authors.lastname: Barbier
authors.forename: C
authors.initials: C
authors.lastname: Dupont
authors.forename: J
authors.initials: J
authors.lastname: Raymond
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000293:Adolescent; D000367:Age Factors; D000658:Amoxicillin / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D000897:Anti-Ulcer Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D017291:Clarithromycin / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D003627:Data Interpretation, Statistical; D024881:Drug Resistance, Bacterial; D004359:Drug Therapy, Combination / Q000494:pharmacology; D005260:Female; D016481:Helicobacter Infections / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D007223:Infant; D064747:Lansoprazole; D008297:Male; D008795:Metronidazole / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D009853:Omeprazole / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D010403:Penicillin Resistance; D010406:Penicillins / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D012189:Retrospective Studies
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000900:Anti-Bacterial Agents; D000897:Anti-Ulcer Agents; D010406:Penicillins; D064747:Lansoprazole; D008795:Metronidazole; D000658:Amoxicillin; D017291:Clarithromycin; D009853:Omeprazole
vernacular_title: Acquisition d'une résistance secondaire après échec d'un premier traitement lors de l'infection à Helicobacter pylori chez l'enfant.