Detection of high-level tetracycline resistance in clinical isolates of Helicobacter pylori using PCR-RFLP

Abstract

Tetracycline is one of four antibiotics commonly used for the treatment of Helicobacter pylori infection, but its effectiveness is decreasing as the incidence of tetracycline resistance is increasing. In five Brazilian tetracycline-resistant (TetR) H. pylori isolates, high-level tetracycline resistance is mediated by the triple-base-pair substitution AGA926-928→TTC in both 16S rRNA genes, as was previously observed in two independent high-level TetR H. pylori strains. A polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) assay was developed for the detection of the AGA926-928→TTC substitution, and confirmed the presence of the aforementioned triple-base-pair substitution in all five Brazilian TetR isolates. This PCR-RFLP-based approach distinguishes the high-level TetR isolates from low-level TetR and TetS H. pylori strains and thus allows the direct detection of TetR H. pylori isolates. © 2003 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.