Abstract
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 TetRH. 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 TetSH. pylori strains and thus allows the direct detection of TetRH. pylori isolates.