Molecular characterization of rifabutin-resistance in refractory Helicobacter pylori infection in Taiwan

Objectives: To explore the molecular characteristics of rpoB , encoding beta-subunit of DNA-directed RNA polymerase, and unravel the link to rifabutin-resistance in patients with refractory Helicobacter pylori infection.Methods: From January 2018-March 2021, a total of 1590 patients were screened for eligibility to participate in the study. Patients with refractory H. pylori infection were confirmed by using the (C-13)-urea breath assay. All enrolled patients underwent esophagogastroduodenoscopy, and biopsies were taken for H. pylori culture and antibacterial susceptibility testing. Sequence analysis of rpoB was conducted for all rifabutin-resistant isolates.Results: In total, 70 patients were diagnosed with refractory H. pylori infection, and 39 isolates were successfully cultured. Amongst, 10 isolates were identified as rifabutin-resistance and nine isolates exhibited at least one amino acid substitution in RpoB. Isolates with a minimal inhibitory concentration > 32 mg/l displayed a higher number of mutational changes in RpoB than the others. Additionally, more amino acid substitutions in RpoB correlated with developing a higher minimal inhibitory concentration for H. pylori rifabutin-resistance.Conclusion: Our findings highlight the relationship between rifabutin-resistance in refractory H. pylori infection and specific mutations in RpoB, which will aid the clinical selection of appropriate antibacterial agents with better therapeutic effects.(c) 2023 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license