Investigation of the Resistome of non- <i>Helicobacter pylori Helicobacter</i> Species

Human infections with non- Helicobacter pylori Helicobacter species (NHPH) are rare. The diagnosis of such infection relies strongly on histological methods, as these bacteria cannot be easily cultured. We describe microbiological analyses that were performed on three cases of infection reported between 2020 and 2023, for which molecular biology was used to identify the species and facilitate the investigation of markers of resistance to macrolides and fluoroquinolones. 16S rRNA sequencing identified two Helicobacter suis strains and one Helicobacter heilmannii sensu stricto strain. Sequencing of 23S rRNA and quinolone resistance determining region of the gyrA gene, classically described as carrying mutations associated with resistance to macrolide and levofloxacin, respectively, did not reveal any mutations. RIDA ® GENE H. pylori , the Allplex™ H. pylori and ClariR Assay and Amplidiag ® H. pylori +ClariR cross-react with these NHPH strains. Any case of NHPH infection diagnosed by histology should be confirmed by molecular biology in specialized laboratories to identify the species and investigate the resistome.