ace, Which Encodes an Adhesin in Enterococcus faecalis, Is Regulated by Ers and Is Involved in Virulence

François Lebreton (1) , Eliette Riboulet-Bisson (1) , Pascale Serror (2) , Maurizio Sanguinetti (3) , Brunella Posteraro (3) , Riccardo Torelli (3) , Axel Hartke (1) , Yanick Auffray (1) , Jean-Christophe Giard (1)

1 LME - Laboratoire de Microbiologie de l’Environnement
2 UBLO - Bactéries Lactiques et Pathogènes Opportunistes
3 Istituto di Microbiologia - Institute of Microbiology [Rome]

Enterococcus faecalis is an opportunistic pathogen that causes numerous infectious diseases in humans and is a major agent of nosocomial infections. In this work, we showed that the recently identified transcriptional regulator Ers (PrfA like), known to be involved in the cellular metabolism and the virulence of E. faecalis, acts as a repressor of ace, which encodes a collagen-binding protein. We characterized the promoter region of ace, and transcriptional analysis by reverse transcription-quantitative PCR and mobility shift protein-DNA binding assays revealed that Ers directly regulates the expression of ace. Transcription of ace appeared to be induced by the presence of bile salts, probably via the deregulation of ers. Moreover, with an ace deletion mutant and the complemented strain and by using an insect (Galleria mellonella) virulence model, as well as in vivo-in vitro murine macrophage models, we demonstrated for the first time that Ace can be considered a virulence factor for E. faecalis. Furthermore, animal experiments revealed that Ace is also involved in urinary tract infection by E. faecalis.

Domains: Life Sciences [q-bio]; Life Sciences [q-bio]; Biochemistry, Molecular Biology

François Lebreton, Eliette Riboulet-Bisson, Pascale Serror, Maurizio Sanguinetti, Brunella Posteraro, et al.. ace, Which Encodes an Adhesin in Enterococcus faecalis, Is Regulated by Ers and Is Involved in Virulence. Infection and Immunity, 2009, 77 (7), pp.2832-2839. ⟨10.1128/IAI.01218-08⟩. ⟨hal-02180975⟩