title: Screening of in vivo activated genes in Enterococcus faecalis during insect and mouse infections and growth in urine.
abstract: Enterococcus faecalis is part of the commensal microbiota of humans and its main habitat is the gastrointestinal tract. Although harmless in healthy individuals, E. faecalis has emerged as a major cause of nosocomial infections. In order to better understand the transformation of a harmless commensal into a life-threatening pathogen, we developed a Recombination-based In VivoExpression Technology for E. faecalis. Two R-IVET systems with different levels of sensitivity have been constructed in a E. faecalis V583 derivative strain and tested in the insect model Galleria mellonella, during growth in urine, in a mouse bacteremia and in a mouse peritonitis model. Our combined results led to the identification of 81 in vivo activated genes. Among them, the ef_3196/7 operon was shown to be strongly induced in the insect host model. Deletion of this operonic structure demonstrated that this two-component system was essential to the E. faecalis pathogenic potential in Galleria. Gene ef_0377, induced in insect and mammalian models, has also been further analyzed and it has been demonstrated that this ankyrin-encoding gene was also involved in E. faecalis virulence. Thus these R-IVET screenings led to the identification of new E. faecalis factors implied in in vivo persistence and pathogenic potential of this opportunistic pathogen.
authors.affiliation: Laboratoire de Microbiologie de l'Environnement, EA956 USC INRA2017, Université de Caen, Caen, France.
authors.forename: Aurelie
authors.initials: A
authors.lastname: Hanin
authors.forename: Irina
authors.initials: I
authors.lastname: Sava
authors.forename: YinYin
authors.initials: Y
authors.lastname: Bao
authors.forename: Johannes
authors.initials: J
authors.lastname: Huebner
authors.forename: Axel
authors.initials: A
authors.lastname: Hartke
authors.forename: Yanick
authors.initials: Y
authors.lastname: Auffray
authors.forename: Nicolas
authors.initials: N
authors.lastname: Sauvageot
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D013293:Enterococcus faecalis / Q000235:genetics* / Q000502:physiology; D005260:Female; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics / Q000502:physiology*; D007313:Insecta / Q000382:microbiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D016133:Polymerase Chain Reaction; D014556:Urine / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins