title: In vitro effect of bergamot (Citrus bergamia) juice against cagA-positive and-negative clinical isolates of Helicobacter pylori.
abstract: BACKGROUND
  Helicobacter pylori infection has been associated with chronic gastritis, peptic ulcer and gastric carcinoma as over half of the world's population is colonized with this gram-negative bacterium. Due to the increasing antibiotic resistance, its eradication rates fails in a great portion of patients. A number of studies showed that molecules largely distributed in commonly consumed fruits and vegetables may have antimicrobial activity. The aim of the present study was to investigate the effect of bergamot juice (BJ) against Helicobacter pylori in vitro. The potential therapeutic combination between BJ and the antibiotics amoxicillin (AMX), clarithromycin (CLA) and metronidazole (MTZ) has also been evaluated.
  
  
  METHODS
  The minimum inhibitory concentration (MIC) of BJ, AMX, CLA and MTZ against 2 ATCC and 32 clinical isolates of H. pylori was assayed according to CLSI. The checkerboard method was used to determine the efficacy of the association BJ with the three reference antibiotics. Killing curves were performed on the two cagA-positive ATCC strains of H. pylori (ATCC 43504 and ATCC 49503), on the clinical isolate cagA-positive HP6 strain of H. pylori and on the clinical isolate cagA-negative HP61 strain of H. pylori.
  
  
  RESULTS
  BJ (2.5%, v/v) inhibited the growth of 50% of the H. pylori clinical isolates, whereas 5% (v/v) inhibited 90%. AMX was the most effective antibiotic against the reference strains and the clinical isolates, followed by CLA and MTZ. In the combination assays, synergism was observed between BJ and AMX and between BJ and MTZ against both the reference strains and the clinical isolates. Indifference was observed between BJ and CLA.
  
  
  CONCLUSIONS
  BJ was effective in vitro against H. pylori and the genotype status of the clinical strains may have an impact on its susceptibility. The synergistic combination of BJ and antibiotics could be used to prevent or treat resistance.
authors.affiliation: Dipartimento di Scienze del Farmaco e Prodotti per la Salute, University of Messina, Viale Annunziata, 98168, Messina, Italy. afilocamo@unime.it.
authors.forename: Angela
authors.initials: A
authors.lastname: Filocamo
authors.affiliation: Dipartimento di Scienze Biologiche e Ambientali, University of Messina, Sal. Sperone 31, 98166, Messina, Italy. carlo.bisignano@unime.it.
authors.forename: Carlo
authors.initials: C
authors.lastname: Bisignano
authors.affiliation: Dipartimento di Scienze del Farmaco e Prodotti per la Salute, University of Messina, Viale Annunziata, 98168, Messina, Italy. nferlazzo@unime.it.
authors.forename: Nadia
authors.initials: N
authors.lastname: Ferlazzo
authors.affiliation: Dipartimento di Scienze del Farmaco e Prodotti per la Salute, University of Messina, Viale Annunziata, 98168, Messina, Italy. scirmi@unime.it.
authors.forename: Santa
authors.initials: S
authors.lastname: Cirmi
authors.affiliation: Dipartimento di Scienze del Farmaco e Prodotti per la Salute, University of Messina, Viale Annunziata, 98168, Messina, Italy. gmandalari@unime.it.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Mandalari
authors.affiliation: Dipartimento di Scienze del Farmaco e Prodotti per la Salute, University of Messina, Viale Annunziata, 98168, Messina, Italy. mnavarra@unime.it.
authors.forename: Michele
authors.initials: M
authors.lastname: Navarra
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D001628:Beverages; D002957:Citrus / Q000737:chemistry*; D005260:Female; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010936:Plant Extracts / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D010936:Plant Extracts; C080866:cagA protein, Helicobacter pylori