title: Antimicrobial activity of esomeprazole versus omeprazole against Helicobacter pylori.
abstract: OBJECTIVE
  Esomeprazole is an enantiomorph of omeprazole, which inhibits gastric acid secretion more effectively than omeprazole. As proton pump inhibitors also exert an antibacterial activity, we aimed to compare esomeprazole and omeprazole for their antimicrobial activity against Helicobacter pylori in vitro.
  
  
  METHODS
  We studied 52 H. pylori isolates obtained from gastric biopsies and inoculated onto agar plates containing the acid-converted drugs at different concentrations. The minimal concentrations that inhibited the growth of 50% and 90% of isolates were defined as MIC(50) and MIC(90).
  
  
  RESULTS
  The MIC(50) and MIC(90) of esomeprazole were 16 and 32 mg/L; and those of omeprazole were 32 and 64 mg/L. Overall, 63.5% of isolates showed the same susceptibility to both drugs; 17 isolates were two- to 64-fold more susceptible to esomeprazole and two isolates were two-fold more susceptible to omeprazole.
  
  
  CONCLUSIONS
  The increased antimicrobial activity in vitro of esomeprazole against H. pylori could contribute to improving the outcome of the eradication treatment of such an infection.
authors.affiliation: Department of Internal Medicine and Gastroenterology, University of Bologna, via Massarenti 9, 40138 Bologna, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Gatta
authors.forename: Federico
authors.initials: F
authors.lastname: Perna
authors.forename: Natale
authors.initials: N
authors.lastname: Figura
authors.forename: Chiara
authors.initials: C
authors.lastname: Ricci
authors.forename: John
authors.initials: J
authors.lastname: Holton
authors.forename: Luigi
authors.initials: L
authors.lastname: D'Anna
authors.forename: Mario
authors.initials: M
authors.lastname: Miglioli
authors.forename: Dino
authors.initials: D
authors.lastname: Vaira
mesh_terms: D000328:Adult; D000897:Anti-Ulcer Agents / Q000494:pharmacology*; D064098:Esomeprazole; D005260:Female; D016481:Helicobacter Infections / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009853:Omeprazole / Q000494:pharmacology*
chemical_list: D000897:Anti-Ulcer Agents; D009853:Omeprazole; D064098:Esomeprazole