title: Appropriateness of Repeating Helicobacter pylori Culture and Susceptibility Testing Following Failure of Individualized Antibiotic Therapy.
abstract: BACKGROUND
  Current guidelines recommend direct Helicobacter pylori culture and antibiotic susceptibility testing following 2 failed eradication attempts. If this process is followed and yet subsequent treatment is unsuccessful, it is unclear whether susceptibility testing should be repeated. This is the first study to examine the appropriateness of repeated H. pylori culture and susceptibility testing following failure of individualized treatment.
  
  
  METHODS
  Between 2007 and 2014, consecutive patients who underwent at least 2 upper gastrointestinal endoscopies with H. pylori culture and susceptibility testing at our institution following several treatment failures were retrospectively identified. Antibiotic susceptibility was recorded and linked to demographic data.
  
  
  RESULTS
  A total of 68 cultures from 34 patients were included (12 (35.3%) men, 41.4 ± 16.6 years), and 20 (58.8%) cultures had a different antibiotic susceptibility profile on repeat testing (8 (23.5%) with new susceptibility and 13 (38.2%) with new resistance). Acquired resistance to clarithromycin, levofloxacin and metronidazole was observed in 9 (26.5%), 2 (5.9%) and 10 (29.4%) cultures, respectively. Subjects with resistance to ≤1 antibiotic at baseline were more likely to develop resistance to at least 1 antibiotic on subsequent culture, compared to subjects with resistance to ≥2 antibiotics at baseline (13 (100%) vs. 5 (23.8%), p < 0.01).
  
  
  CONCLUSIONS
  Repeating H. pylori culture and susceptibility testing usually yields new antimicrobial susceptibility data. However, the clinical usefulness of this approach remains unclear.
authors.affiliation: Department of Gastroenterology, Rabin Medical Center, Beilinson Campus, Petah Tikva and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Doron
authors.initials: D
authors.lastname: Boltin
authors.forename: Haim
authors.initials: H
authors.lastname: Ben-Zvi
authors.forename: Tsachi Tsadok
authors.initials: TT
authors.lastname: Perets
authors.forename: Rachel
authors.initials: R
authors.lastname: Gingold-Belfer
authors.forename: Ram
authors.initials: R
authors.lastname: Dickman
authors.forename: Yaron
authors.initials: Y
authors.lastname: Niv
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D018929:Cell Culture Techniques; D024901:Drug Resistance, Multiple, Bacterial; D004359:Drug Therapy, Combination / Q000379:methods; D016099:Endoscopy, Gastrointestinal; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007557:Israel; D008297:Male; D008795:Metronidazole / Q000494:pharmacology / Q000627:therapeutic use*; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D057285:Precision Medicine / Q000379:methods*; D012189:Retrospective Studies; D017211:Treatment Failure; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D008795:Metronidazole