Primary antibiotic resistance in Helicobacter pylori strains isolated in northern and central Italy

Aliment Pharmacol Ther. 2007 Jun 15;25(12):1429-34. doi: 10.1111/j.1365-2036.2007.03331.x.


Background: Helicobacter pylori resistance to antibiotics is increasing worldwide, and it reduces the efficacy of therapy.

Aim: To assess current primary antibiotic resistance in H. pylori strains isolated in Italy.

Methods: Between June 2004 and June 2006, H. pylori strains were isolated consecutively in the two participating centres (Bologna, northern Italy; Rome, central Italy) from patients never previously treated for the infection. Isolated strains were tested for primary clarithromycin, metronidazole and levofloxacin resistance using as break point the minimal inhibitory concentration >/=1, >/=8 and >/=1 mg/L for the three antibiotics, respectively.

Results: Overall, 255 H. pylori strains were evaluated. The resistance rate was 16.9% for clarithromycin, 29.4% for metronidazole and 19.1% for levofloxacin. Clarithromycin resistance was significantly higher in non-ulcer dyspepsia than in peptic ulcer patients (19.1% vs. 0%, P = 0.02), metronidazole resistance was higher in foreign than Italian patients (50% vs. 22.9%, P = 0.0004) and levofloxacin resistance was higher in old than younger patients (28.4% vs. 14.4%, P = 0.048). Levofloxacin resistance was also more frequent in those strains with either clarithromycin or metronidazole resistance.

Conclusion: A very high rate of primary resistance towards the tested antibiotics was detected in our study.

Publication types

  • Multicenter Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / therapeutic use*
  • Clarithromycin / therapeutic use
  • Drug Resistance / drug effects*
  • Drug Resistance, Multiple, Bacterial
  • Female
  • Helicobacter Infections / drug therapy*
  • Helicobacter pylori / drug effects*
  • Humans
  • Levofloxacin
  • Male
  • Metronidazole / therapeutic use
  • Middle Aged
  • Ofloxacin / therapeutic use
  • Treatment Outcome


  • Anti-Bacterial Agents
  • Metronidazole
  • Levofloxacin
  • Ofloxacin
  • Clarithromycin