title: Involvement of Enterococcus faecalis small RNAs in stress response and virulence.
abstract: Candidate small RNAs (sRNAs) have recently been identified in Enterococcus faecalis, a Gram-positive opportunistic pathogen, and six of these candidate sRNAs with unknown functions were selected for a functional study. Deletion mutants and complemented strains were constructed, and their virulence was tested. We were unable to obtain the ef0869-0870 mutant, likely due to an essential role, and the ef0820-0821 sRNA seemed not to be involved in virulence. In contrast, the mutant lacking ef0408-0409 sRNA, homologous to the RNAII component of the toxin-antitoxin system, appeared more virulent and more able to colonize mouse organs. The three other mutants showed reduced virulence. In addition, we checked the responses of these mutant strains to several stresses encountered in the gastrointestinal tract or during the infection process. In parallel, the activities of the sRNA promoters were measured using transcriptional fusion constructions. To attempt to identify the regulons of these candidate sRNAs, proteomics profiles of the mutant strains were compared with that of the wild type. This showed that the selected sRNAs controlled the expression of proteins involved in diverse cellular processes and the stress response. The combined data highlight the roles of certain candidate sRNAs in the adaptation of E. faecalis to environmental changes and in the complex transition process from a commensal to a pathogen.
authors.affiliation: Unité de Recherche Risques Microbiens (U2RM), Equipe Stress Virulence, Université de Caen, Caen, France.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Michaux
authors.affiliation: Unité de Recherche Risques Microbiens (U2RM), Equipe Stress Virulence, Université de Caen, Caen, France.
authors.forename: Axel
authors.initials: A
authors.lastname: Hartke
authors.affiliation: Unité de Recherche Risques Microbiens (U2RM), Equipe Stress Virulence, Université de Caen, Caen, France Institute of Microbiology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Martini
authors.affiliation: Institut für Mikrobiologie, Ernst-Moritz-Arndt-Universität, Greifswald, Germany.
authors.forename: Swantje
authors.initials: S
authors.lastname: Reiss
authors.affiliation: Institut für Mikrobiologie, Ernst-Moritz-Arndt-Universität, Greifswald, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Albrecht
authors.affiliation: Unité de Recherche Risques Microbiens (U2RM), Equipe Stress Virulence, Université de Caen, Caen, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Budin-Verneuil
authors.affiliation: Institute of Microbiology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Sanguinetti
authors.affiliation: Institut für Mikrobiologie, Ernst-Moritz-Arndt-Universität, Greifswald, Germany Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Engelmann
authors.affiliation: Institute of Medical Microbiology, Justus-Liebig-University, Giessen, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Hain
authors.affiliation: Unité de Recherche Risques Microbiens (U2RM), Equipe Stress Virulence, Université de Caen, Caen, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Verneuil
authors.affiliation: Equipe Antibio-Résistance, Université de Caen, Caen, France jean-christophe.giard@unicaen.fr.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Giard
mesh_terms: D000818:Animals; D013293:Enterococcus faecalis / Q000235:genetics*; D005260:Female; D041981:Gastrointestinal Tract / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D016908:Gram-Positive Bacterial Infections / Q000235:genetics / Q000382:microbiology; D008264:Macrophages / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D012329:RNA, Bacterial / Q000235:genetics; D013312:Stress, Physiological / Q000235:genetics*; D014774:Virulence / Q000235:genetics*
chemical_list: D012329:RNA, Bacterial