title: The evolution of Helicobacter pylori antibiotics resistance over 10 years in Greece.
abstract: BACKGROUND
  Increasingly, over time, antibiotic resistance is considered a problem for the efficacy of H. pylori eradication treatment. The aim of our study was to evaluate the changes in clarithromycin and levofloxacin resistance of H. pylori strains in Greek patients in two different time periods (in 2000 and in 2010).
  
  
  METHODS
  Gastric biopsies of consecutive H. pylori-positive patients were investigated retrospectively. Mutations in H. pylori 23S rRNA and gyrA genes associated with resistance to clarithromycin and quinolones, respectively, were determined by allelic specific polymerase chain reaction.
  
  
  RESULTS
  In the first time period (2000), H. pylori resistance patterns were evaluated in 50 and in the second period (2010) in 57 patients. During the first time period 30 and 0% of patients were infected with clarithromycin- or quinolone-resistant strains, respectively. In the second time period (2010), the percentage of patients infected with clarythromycin or quinolone resistance strains increased to 42 and 5.3%, respectively.
  
  
  CONCLUSIONS
  Our study showed an increase in the prevalence of both clarithromycin and quinolones resistance of H. pylori. Although the resistance rate to quinolones increased over the years, it is relatively low justifying its use for the eradication of H. pylori infections.
authors.affiliation: Academic Department of Gastroenterology, Athens Medical School, 'Laikon' GH, Athens, Greece.
authors.forename: Georgios P
authors.initials: GP
authors.lastname: Karamanolis
authors.forename: George L
authors.initials: GL
authors.lastname: Daikos
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Xouris
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Goukos
authors.forename: Ioanna
authors.initials: I
authors.lastname: Delladetsima
authors.forename: Spiros D
authors.initials: SD
authors.lastname: Ladas
mesh_terms: D017291:Clarithromycin; D027081:DNA Gyrase / Q000235:genetics*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005787:Gene Frequency; D006115:Greece / Q000453:epidemiology; D016481:Helicobacter Infections / Q000453:epidemiology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics*; D006801:Humans; D064704:Levofloxacin; D017720:Molecular Epidemiology; D009154:Mutation; D020641:Polymorphism, Single Nucleotide; D015995:Prevalence; D012338:RNA, Ribosomal, 23S / Q000235:genetics*; D012189:Retrospective Studies
chemical_list: D012338:RNA, Ribosomal, 23S; D064704:Levofloxacin; D027081:DNA Gyrase; D017291:Clarithromycin