title: High Helicobacter pylori resistance to metronidazole and clarithromycin in Brazilian children and adolescents.
abstract: OBJECTIVE
  The aim of the present study was to assess the primary and secondary resistance of Helicobacter pylori strains to clarithromycin, amoxicillin, furazolidone, tetracycline, and metronidazole, the conventional antibiotics presently used in Brazilian children and adolescents.
  
  
  METHODS
  Seventy-seven consecutive H pylori strains, 71 of 77 strains obtained from patients without previous eradication treatment for H pylori infection, and 6 strains from patients in whom previous eradication treatment had failed.
  
  
  RESULTS
  Global rate of resistance was 49.3% (38/77): 40% of strains were resistant to metronidazole, 19.5% to clarithromycin, and 10.4% to amoxicillin. All of the tested H pylori strains were susceptible to furazolidone and tetracycline. Multiple resistance were detected in 18.2% (14/77 patients) of the strains: 6 of 14 (43%) simultaneously resistant to clarithromycin and metronidazole; 5 of 14 (36%) to amoxicillin and metronidazole; 2 of 14 (14%) to amoxicillin, clarithromycin, and metronidazole; and 1 of 14 (7%) to clarithromycin and amoxicillin.
  
  
  CONCLUSIONS
  The high resistance rate to metronidazole and clarithromycin observed in clinical H pylori isolates can exclude these antimicrobials in empirical eradication treatment in Brazil. Otherwise, furazolidone and tetracycline presented no resistance. Properly assessing the risks and benefits, these 2 antimicrobials and their derivatives could be used in empirical eradication schedules, both associated with amoxicillin, which showed a low resistance rate despite its wide use in pediatric patients.
authors: Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil. skogata@unifesp.br
authors: Silvio K
authors: SK
authors: Ogata
authors: Anita P Ortiz
authors: AP
authors: Godoy
authors: Francy R
authors: FR
authors: da Silva Patricio
authors: Elisabete
authors: E
authors: Kawakami
mesh_terms: D000293:Adolescent; D000328:Adult; D000658:Amoxicillin / Q000494:pharmacology / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics* / Q000627:therapeutic use; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D017291:Clarithromycin / Q000494:pharmacology* / Q000627:therapeutic use; D003906:Developing Countries; D060740:Disease Eradication; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D005664:Furazolidone / Q000494:pharmacology / Q000627:therapeutic use; D016481:Helicobacter Infections / Q000188:drug therapy / Q000382:microbiology* / Q000517:prevention & control; D016480:Helicobacter pylori / Q000187:drug effects* / Q000254:growth & development; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000494:pharmacology* / Q000627:therapeutic use; D008826:Microbial Sensitivity Tests; D013752:Tetracycline / Q000494:pharmacology / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D008795:Metronidazole; D005664:Furazolidone; D000658:Amoxicillin; D013752:Tetracycline; D017291:Clarithromycin