Objective To analyze the molecular characteristics of antibiotic resistance in Helicobacter pylori (HP) and provide a molecular biological basis for clinical eradication of HP by means of rational antibiotic use.

Methods From February 2019 to November 2023, 1,144 patients at the Gansu Wuwei Cancer Hospital who tested positive for HP using the ¹⁴C-urea breath test were enrolled in the study. Antibiotic resistance and related molecular characteristics of HP, and CYP2C19 polymorphisms in the patients were detected by diffusion drug susceptibility testing, drug resistance gene testing, and next-generation sequencing, respectively.

Results  Among the six antibiotics assessed, the resistance rate and the prevalence of resistance genes (rdxA) were highest for metronidazole (92.00% and 86.12%, respectively), and lowest for amoxicillin (Pbp1)(11.78% and 37.11%, respectively). The prevalence of CYP2C19 alleles showed that 46.77%, 44.58%, and 8.65% of participants were fast, medium, and slow metabolizers, respectively. Of the participants, 148 (18.55%) had immunohistochemical sphericity. The eradication rate of HP lower using conventional treatment regimens than that using personalized treatment regimens (χ²=8.627, P=0.003). The HP eradication rate was higher among patients with a first diagnosis of drug resistancebased on molecular testing, than that in patients undergoing retreatment (χ²=6.242, P=0.012).

Conclusions The prevalence of amoxicillin-resistant HP is low in Wuwei City, which has a high incidence of gastric cancer. Molecular diagnosis of antimicrobial resistance could improve the HP eradication rate and provide a reference for rational use of antibiotics in clinical practice.