Role of antimicrobial susceptibility testing on efficacy of triple therapy in Helicobacter pylori eradication

Background: Helicobacter pylori treatment failure may be due to resistance to macrolides and 5-nitroimidazoles. Aim: To test whether a preliminary in vitro susceptibility test of H. pylori to tinidazole and clarithromycin and a consequent specific regimen could improve the eradication rate. Methods: A total of 109 consecutive H. pylori-positive patients with dyspeptic symptoms were included. At endoscopy, biopsy from the antrum was obtained for H. pylori culture and antimicrobial susceptibility testing. Fifty-six patients were treated with omeprazole, tinidazole and clarithromycin for 10 days (group OTC) and 53 patients received therapy on the basis of the susceptibility test (group SUSC). Treatment success was evaluated by the C-13-urea breath test 1 month after the end of therapy. Results: Eight patients dropped out. Overall primary resistance to clarithromycin, tinidazole and both antibiotics was 13%, 33% and 4%, respectively. In group OTC, H. pylori was eradicated in 81% and 75% of patients by per protocol and intention-to-treat analysis, respectively. Per protocol and intention-to-treat eradication rates for group SUSC were 98% and 91% (P < 0.05 vs. group OTC). Conclusions: These data show that in H. pylori infection, antibiotic therapy based on the results of culture and susceptibility testing gives, in comparison to standard therapy, a significant improvement in eradication rate.