title: Distinct SagA from Hospital-Associated Clade A1 Enterococcus faecium Strains Contributes to Biofilm Formation.
abstract: Enterococcus faecium is an important nosocomial pathogen causing biofilm-mediated infections. Elucidation of E. faecium biofilm pathogenesis is pivotal for the development of new strategies to treat these infections. In several bacteria, extracellular DNA (eDNA) and proteins act as matrix components contributing to biofilm development. In this study, we investigated biofilm formation capacity and the roles of eDNA and secreted proteins for 83 E. faecium strains with different phylogenetic origins that clustered in clade A1 and clade B. Although there was no significant difference in biofilm formation between E. faecium strains from these two clades, the addition of DNase I or proteinase K to biofilms demonstrated that eDNA is essential for biofilm formation in most E. faecium strains, whereas proteolysis impacted primarily biofilms of E. faecium clade A1 strains. Secreted antigen A (SagA) was the most abundant protein in biofilms from E. faecium clade A1 and B strains, although its localization differed between the two groups. sagA was present in all sequenced E. faecium strains, with a consistent difference in the repeat region between the clades, which correlated with the susceptibility of biofilms to proteinase K. This indicates an association between the SagA variable repeat profile and the localization and contribution of SagA in E. faecium biofilms.
authors.affiliation: Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: F L
authors.initials: FL
authors.lastname: Paganelli
authors.affiliation: Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: de Been
authors.affiliation: Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: J C
authors.initials: JC
authors.lastname: Braat
authors.affiliation: Laboratory of Pediatrics, Pediatric Infectious Diseases and Immunity, Erasmus MC, Sophia Children's Hospital, Rotterdam, The Netherlands Erasmus University College, Department of Life Sciences, Erasmus University Rotterdam, Rotterdam, The Netherlands.
authors.forename: T
authors.initials: T
authors.lastname: Hoogenboezem
authors.affiliation: Laboratory of Pediatrics, Pediatric Infectious Diseases and Immunity, Erasmus MC, Sophia Children's Hospital, Rotterdam, The Netherlands Erasmus University College, Department of Life Sciences, Erasmus University Rotterdam, Rotterdam, The Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: Vink
authors.affiliation: Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Bayjanov
authors.affiliation: Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: M R C
authors.initials: MR
authors.lastname: Rogers
authors.affiliation: Division of Pediatric Infectious Diseases, Hauner Children's Hospital, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Huebner
authors.affiliation: Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: M J M
authors.initials: MJ
authors.lastname: Bonten
authors.affiliation: Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: R J L
authors.initials: RJ
authors.lastname: Willems
authors.affiliation: Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands h.leavis@umcutrecht.nl.
authors.forename: H L
authors.initials: HL
authors.lastname: Leavis
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D018441:Biofilms; D003428:Cross Infection / Q000382:microbiology*; D016984:Enterococcus faecium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology*; D006761:Hospitals; D008969:Molecular Sequence Data; D010802:Phylogeny
chemical_list: D001426:Bacterial Proteins