title: Necessity of multiple gastric biopsies from different sites for detection of clarithromycin-resistant Helicobacter pylori strains.
abstract: BACKGROUND
  It has been reported that approximately 10% of patients infected with Helicobacter pylori have both clarithromycin-susceptible and clathromycin-resistant strains. However, there have been no reports indicating whether only one gastric biopsy is sufficient to detect clarithromycin-resistant strains.
  
  
  METHODS
  Sixty-five H. pylori-infected patients were selected for this study, and 40 of them were given clarithromycin-based eradication therapy. Four gastric biopsies, 2 from the antrum and 2 from the corpus, were obtained from each of the 65 patients. Susceptibility of H. pylori strains to clarithromycin was examined by detecting mutations of the 23S ribosomal RNA (rRNA) gene of H. pylori.
  
  
  RESULTS
  The clarithromycin-resistant strains were detected in 16 of the 65 (25%) patients. Only 5 of the 16 (31%) patients had the resistant strains in both the antrum and corpus. When only 1 or the other biopsy from the antrum was used, the resistant strains were detected in 8 (50%) or 9 (56%) of the 16 patients.
  
  
  CONCLUSIONS
  These data indicate that multiple gastric biopsies from both the antrum and the corpus should be used to detect clarithromycin-resistant H. pylori strains.
authors.affiliation: Dept. of Medicine and Molecular Science, Division of Frontier Medical Science, Programs for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Masuda
authors.forename: T
authors.initials: T
authors.lastname: Hiyama
authors.forename: M
authors.initials: M
authors.lastname: Yoshihara
authors.forename: S
authors.initials: S
authors.lastname: Tanaka
authors.forename: F
authors.initials: F
authors.lastname: Shimamoto
authors.forename: K
authors.initials: K
authors.lastname: Haruma
authors.forename: K
authors.initials: K
authors.lastname: Chayama
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001706:Biopsy / Q000379:methods; D017291:Clarithromycin / Q000627:therapeutic use*; D024881:Drug Resistance, Bacterial; D005260:Female; D020459:Genes, rRNA / Q000235:genetics; D016481:Helicobacter Infections / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D016480:Helicobacter pylori / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction; D011706:Pyloric Antrum / Q000382:microbiology / Q000473:pathology; D013270:Stomach / Q000382:microbiology / Q000473:pathology*
chemical_list: D000900:Anti-Bacterial Agents; D017291:Clarithromycin