Fluoroquinolone resistance of H. pylori was caused by gyrA Asn-87 and Asp-91 point mutations. The Asn-87 mutation seems to be an important determinant of failure of fluoroquinolone-containing triple eradication therapy based on eradication results.

Background The eradication rate of Helicobacter pylori has declined, mainly due to antimicrobial resistance. To overcome resistance‐associated treatment failure, the efficacy of culture‐based, susceptibility‐guided therapy was demonstrated as the first‐line eradication therapy for H pylori infection. Aims To evaluate the efficacy of culture‐based therapy as the first‐line eradication therapy in regions with high levels of antimicrobial resistance. Methods Helicobacter pylori‐positive patients without previous eradication treatment history were recommended to undergo culture to determine the minimal inhibitory concentration (MIC). If they consented, 7‐day clarithromycin‐containing PPI triple; 7‐day esomeprazole, moxifloxacin, and amoxicillin (MEA) therapy; or 7‐ or 14‐day esomeprazole, bismuth, metronidazole, and tetracycline (quadruple) therapy were administered based on the agar dilution‐determined MIC. Eradication, treatment compliance, and adverse events were examined. Results In total, 74 patients were enrolled, and 69 patients completed the protocols. The overall resistance rates to amoxicillin, clarithromycin, metronidazole, and moxifloxacin were 6.7%, 31.0%, 41.8%, and 39.2%, respectively. The patients were allocated to the PPI triple (n = 50), MEA (n = 8) or quadruple (n = 16) therapy. The eradication rate in the intention‐to‐treat analysis was 93.1% (69 of 74 patients). The eradication rates in the per‐protocol analysis were 100.0% (69 of 69 patients). Epigastric pain, nausea, and vomiting were less common than those of other empirical therapies. Conclusions Culture‐based, susceptibility‐guided therapy is effective first‐line eradication therapy, especially in regions with high levels of antimicrobial resistance.