A 10-year microbiological study of Pseudomonas aeruginosa strains revealed the circulation of populations resistant to both carbapenems and quaternary ammonium compounds

Marine Pottier (1, 2) , François Gravey (1, 3) , Sophie Castagnet (1, 2) , Michel Auzou (3) , Bénédicte Langlois (3) , François Guérin (4) , Jean-Christophe Giard (1) , Albertine Léon (1, 2) , Simon Le Hello (1, 3, 5)

1 DYNAMICURE - Dynamique Microbienne associée aux Infections Urinaires et Respiratoires
2 LABÉO - LABÉO, Pôle d’analyses et de recherche de Normandie
3 Service de Microbiologie [CHU Caen]
4 Laboratoire de Bactériologie et Hygiène Hospitalière [Rennes]
5 Département d'Hygiène Hospitalière [CHU Caen]

Pseudomonas aeruginosa is one of the leading causes of healthcare-associated infections. For this study, the susceptibility profiles to antipseudomonal antibiotics and a quaternary ammonium compound, didecyldimethylammonium chloride (DDAC), widely used as a disinfectant, were established for 180 selected human and environmental hospital strains isolated between 2011 and 2020. Furthermore, a genomic study determined resistome and clonal putative relatedness for 77 of them. During the ten-year study period, it was estimated that 9.5% of patients’ strains were resistant to carbapenems, 11.9% were multidrug-resistant (MDR), and 0.7% were extensively drug-resistant (XDR). Decreased susceptibility (DS) to DDAC was observed for 28.0% of strains, a phenotype significantly associated with MDR/XDR profiles and from hospital environmental samples ( p < 0.0001). According to genomic analyses, the P. aeruginosa population unsusceptible to carbapenems and/or to DDAC was diverse but mainly belonged to top ten high-risk clones described worldwide by del Barrio-Tofiño et al. The carbapenem resistance appeared mainly due to the production of the VIM-2 carbapenemase (39.3%) and DS to DDAC mediated by MexAB-OprM pump efflux overexpression. This study highlights the diversity of MDR/XDR populations of P. aeruginosa which are unsusceptible to compounds that are widely used in medicine and hospital disinfection and are probably distributed in hospitals worldwide.

Domaines: Microbiologie et Parasitologie

Marine Pottier, François Gravey, Sophie Castagnet, Michel Auzou, Bénédicte Langlois, et al.. A 10-year microbiological study of Pseudomonas aeruginosa strains revealed the circulation of populations resistant to both carbapenems and quaternary ammonium compounds. Scientific Reports, 2023, 13 (1), pp.2639. ⟨10.1038/s41598-023-29590-0⟩. ⟨hal-04034542⟩