title: [Changing patterns of antibiotic resistance of Helicobacter pylori in patients with peptic ulcer disease].
abstract: OBJECTIVE
  Antibiotic resistance of Helicobacter pylori (H. pylori) is a significant clinical problem because it reduces the efficacy of eradication therapy. The aims of this study were to assess the changing patterns of antibiotic resistance of H. pylori in patients with peptic ulcer diseases and to evaluate the eradication rate in antibiotic resistant H. pylori strains.
  
  
  METHODS
  One hundred forty four H. pylori isolates obtained from 466 patients with peptic ulcer disease between June 2001 and December 2005 were examined for antimicrobial resistance. The minimum inhibitory concentration (MIC) of metronidazole was determined by modified broth microdilution method (mBMD) and E test. MICs of clarithromycin and amoxicillin were determined by mBMD, E test, and disc diffusion test. The breakpoints for metronidazole, clarithromycin, and amoxicillin resistance were defined as >8 microg/mL, >1 microg/mL, and > or =1 microg/mL, respectively.
  
  
  RESULTS
  Resistance to metronidazole and clarithromycin was detected in 34.7% and 16.7% of H. pylori isolates, respectively. During the recent 5-year study period, amoxicillin-resistant rate of H. pylori was 11.8%, and multi-drug resistance rate of H. pylori was 16.7%. The eradication rate of clarithromycin containing triple therapies was low (7.8%) in clarithromycin-resistant H. pylori strains.
  
  
  CONCLUSIONS
  The proportions of clarithromycin-resistant H. pylori strains have increased significantly over the last 5-years. There is an increasing tendency for the emergence of strains with multi-drug resistance. The increase in clarithromycin-resistant strains results in a decrease in eradication rate for H. pylori. In areas with high clarithromycin resistance, new alternative first-line treatment combination should be considered.
authors.affiliation: Department of Internal Medicine, Hanyang University College of Medicine, Guri, Korea.
authors.forename: So Young
authors.initials: SY
authors.lastname: Bang
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Han
authors.forename: Chang Soo
authors.initials: CS
authors.lastname: Eun
authors.forename: Ji Eun
authors.initials: JE
authors.lastname: Kim
authors.forename: Sang Bong
authors.initials: SB
authors.lastname: Ahn
authors.forename: Joo Hyun
authors.initials: JH
authors.lastname: Sohn
authors.forename: Yong Cheol
authors.initials: YC
authors.lastname: Jeon
authors.forename: Jung Oak
authors.initials: JO
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D000658:Amoxicillin / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D017291:Clarithromycin / Q000009:adverse effects / Q000627:therapeutic use; D052978:Disk Diffusion Antimicrobial Tests; D024881:Drug Resistance, Bacterial; D004359:Drug Therapy, Combination; D005260:Female; D016481:Helicobacter Infections / Q000188:drug therapy* / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000627:therapeutic use; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010437:Peptic Ulcer / Q000188:drug therapy*; D012189:Retrospective Studies
chemical_list: D000900:Anti-Bacterial Agents; D008795:Metronidazole; D000658:Amoxicillin; D017291:Clarithromycin