Detection of highly macrolide-resistant Legionella pneumophila strains from a hotel water network using systematic whole-genome sequencing

Publié le 9 juin 2022
Mis à jour le 24 octobre 2022

OBJECTIVES: Implementation of an antibiotic resistance detection tool in Legionella daily surveillance at the French National Reference Centre for Legionella. METHODS: Systematic WGS of Legionella pneumophila isolates and bioinformatics detection of specific mutations linked to antibiotic resistance. Phenotypic validation of antibiotic resistance detected by WGS was performed by the broth microdilution method. RESULTS: More than 3000 L. pneumophila strains were screened for antibiotic resistance. A macrolide resistance-associated A2052G mutation in the 23S rRNA gene was identified in the genome of eight isolates from a hotel water network. High-level macrolide resistance (i.e. MICs of 1024-2048?mg/L for azithromycin and erythromycin) with no cross-resistance to other antimicrobials was phenotypically confirmed by antimicrobial susceptibility testing for the eight isolates. CONCLUSIONS: Systematic WGS of L. pneumophila is a powerful tool for first-line high-throughput screening of antibiotic resistance before phenotypic validation.

Auteur : Ginevra Christophe, Beraud Laetitia, Pionnier Isabelle, Sallabery Kassandra, Bentayeb Houcine, Simon Bruno, Allam Camille, Chastang Joelle, Ibranosyan Marine, Decroix Véronique, Campese Christine, Jarraud Sophie, Descours Ghislaine
The Journal of antimicrobial chemotherapy, 2022, vol. 77, n°. 8, p. 2167-2170