title: High prevalence of primary antibiotic resistance in Helicobacter pylori isolates in Italy.
abstract: OBJECTIVE
  H. pylori eradication with standard therapies is decreasing worldwide, mainly because of increased primary antibiotic resistance rates. We aimed to assess primary resistance in H. pylori isolates towards the most used antibiotics in clinical practice.
  
  
  METHODS
  The study enrolled consecutive, dyspeptic, adult patients, never treated for H. pylori, who had underwent upper endoscopy. Gastric biopsies were taken for standard histology, and two further antral biopsies were used for H. pylori culture. Minimal inhibitory concentrations (MIC) >/= 1, >/= 8 and >/= 1 mg/L were used as break point for clarithromycin, metronidazole, and levofloxacin resistance, respectively.
  
  
  RESULTS
  Bacterial culture was successful in 145 (94%) out of 154 infected patients. Resistance towards at least one antibiotic was detected in 111 (76.6%) isolated, and multiple antibiotic resistance in 35.2% of cases. Primary resistance towards clarithromycin, metronidazole, and levofloxacin was detected in 51 (35.2%), 86 (59.3%), and in 32 isolated (22.1%), respectively. Levofloxacin resistance was significantly associated with the male sex (OR: 11.3, 95% CI = 1.2-103; P = 0.03), whilst females were at a higher risk of being infected with bacterial strains harbouring a double clarithromycin and metronidazole resistance (OR: 4.9, 95% CI = 1.2-19.8, P = 0.02).
  
  
  CONCLUSIONS
  Our data indicate a very high primary resistance rate towards the most used antibiotics in H. pylori isolates. The efficacy of standard eradication therapies is expected to further decrease in the next years.
authors.affiliation: Department of Clinical Medicine, University of Bologna, Italy.
authors.forename: Ilaria M
authors.initials: IM
authors.lastname: Saracino
authors.forename: Angelo
authors.initials: A
authors.lastname: Zullo
authors.forename: John
authors.initials: J
authors.lastname: Holton
authors.forename: Valentina
authors.initials: V
authors.lastname: Castelli
authors.forename: Giulia
authors.initials: G
authors.lastname: Fiorini
authors.forename: Cristina
authors.initials: C
authors.lastname: Zaccaro
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Ridola
authors.forename: Chiara
authors.initials: C
authors.lastname: Ricci
authors.forename: Luigi
authors.initials: L
authors.lastname: Gatta
authors.forename: Dino
authors.initials: D
authors.lastname: Vaira
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017291:Clarithromycin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D004415:Dyspepsia / Q000382:microbiology; D005260:Female; D016481:Helicobacter Infections / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D007558:Italy / Q000453:epidemiology; D064704:Levofloxacin / Q000494:pharmacology; D008297:Male; D008795:Metronidazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests / Q000379:methods; D008875:Middle Aged; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D008795:Metronidazole; D064704:Levofloxacin; D017291:Clarithromycin