title: Galleria mellonella as a model for studying Enterococcus faecium host persistence.
abstract: Enterococcus faecium is an opportunistic pathogen responsible for numerous outbreaks worldwide. The basis for the colonization capacities, host persistence and environmental stress response of the hospital-adapted clones emerging from E. faecium are poorly understood. In this study, we propose the use of Galleria mellonella as a simple nonmammalian model to assess E. faecium host persistence. Various strains (n = 10), including hospital-adapted, commensal or animal isolates and a SodA-deficient strain were used to assess the relevance of this model. Compared to Enterococcus faecalis, E. faecium strains do not appear very lethal in a Galleria killing assay. The ability of E. faecium strains to overcome host-immune responses and multiply within the host system was evaluated by monitoring bacterial loads following Galleria infection. Among the E. faecium strains, two hospital-adapted isolates displayed increased colonization ability. In contrast, inactivation of sodA, encoding a putative manganese-dependent superoxide dismutase, significantly reduced survival of E. faecium to Galleria defenses. Galleria appears to be a suitable and convenient surrogate model to study E. faecium survival to host defenses and the role of suspected virulence factors in the colonization process.
authors.affiliation: EA2128, Service de Microbiologie, Centre Hospitalier Universitaire, Université de Caen Basse-Normandie, Caen, France.
authors.forename: François
authors.initials: F
authors.lastname: Lebreton
authors.forename: Florian
authors.initials: F
authors.lastname: Le Bras
authors.forename: Fany
authors.initials: F
authors.lastname: Reffuveille
authors.forename: Rabia
authors.initials: R
authors.lastname: Ladjouzi
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Giard
authors.forename: Roland
authors.initials: R
authors.lastname: Leclercq
authors.forename: Vincent
authors.initials: V
authors.lastname: Cattoir
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002353:Carrier State / Q000382:microbiology*; D004195:Disease Models, Animal; D016984:Enterococcus faecium / Q000254:growth & development / Q000276:immunology / Q000472:pathogenicity*; D054884:Host-Pathogen Interactions; D006801:Humans; D057131:Immune Evasion; D007915:Lepidoptera / Q000382:microbiology*; D050296:Microbial Viability; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors; C095500:SodA protein, Bacteria; D013482:Superoxide Dismutase