title: Biofilm Morphotypes and Population Structure among Staphylococcus epidermidis from Commensal and Clinical Samples.
abstract: Bacterial species comprise related genotypes that can display divergent phenotypes with important clinical implications. Staphylococcus epidermidis is a common cause of nosocomial infections and, critical to its pathogenesis, is its ability to adhere and form biofilms on surfaces, thereby moderating the effect of the host's immune response and antibiotics. Commensal S. epidermidis populations are thought to differ from those associated with disease in factors involved in adhesion and biofilm accumulation. We quantified the differences in biofilm formation in 98 S. epidermidis isolates from various sources, and investigated population structure based on ribosomal multilocus typing (rMLST) and the presence/absence of genes involved in adhesion and biofilm formation. All isolates were able to adhere and form biofilms in in vitro growth assays and confocal microscopy allowed classification into 5 biofilm morphotypes based on their thickness, biovolume and roughness. Phylogenetic reconstruction grouped isolates into three separate clades, with the isolates in the main disease associated clade displaying diversity in morphotype. Of the biofilm morphology characteristics, only biofilm thickness had a significant association with clade distribution. The distribution of some known adhesion-associated genes (aap and sesE) among isolates showed a significant association with the species clonal frame. These data challenge the assumption that biofilm-associated genes, such as those on the ica operon, are genetic markers for less invasive S. epidermidis isolates, and suggest that phenotypic characteristics, such as adhesion and biofilm formation, are not fixed by clonal descent but are influenced by the presence of various genes that are mobile among lineages.
authors.affiliation: Medical Microbiology & Infectious Diseases, Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, United Kingdom.
authors.forename: Llinos G
authors.initials: LG
authors.lastname: Harris
authors.affiliation: Medical Microbiology & Infectious Diseases, Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, United Kingdom.
authors.forename: Susan
authors.initials: S
authors.lastname: Murray
authors.affiliation: Medical Microbiology & Infectious Diseases, Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, United Kingdom.|MRC CLIMB Consortium, Institute of Life Science, Swansea University, Swansea, United Kingdom.
authors.forename: Ben
authors.initials: B
authors.lastname: Pascoe
authors.affiliation: Department of Zoology, University of Oxford, Oxford, United Kingdom.
authors.forename: James
authors.initials: J
authors.lastname: Bray
authors.affiliation: Medical Microbiology & Infectious Diseases, Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, United Kingdom.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Meric
authors.affiliation: Medical Microbiology & Infectious Diseases, Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, United Kingdom.
authors.forename: Leonardos
authors.initials: L
authors.lastname: Mageiros
authors.affiliation: Medical Microbiology & Infectious Diseases, Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, United Kingdom.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Wilkinson
authors.affiliation: Medical Microbiology & Infectious Diseases, Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, United Kingdom.
authors.forename: Rose
authors.initials: R
authors.lastname: Jeeves
authors.affiliation: Institut für Medizinische Mikrobiologie, Virologie & Hygiene, Universitätsklinikum Hamburg-Eppendorf, Universität Hamburg, Hamburg, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Rohde
authors.affiliation: Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Neustadt-Mariensee, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schwarz
authors.affiliation: Laboratory for Molecular Genetics, Instituto de Tecnologia Química e Biológica, Oeiras, Portugal.|Laboratory of Microbiology, The Rockefeller University, New York, New York, United States of America.
authors.forename: Herminia
authors.initials: H
authors.lastname: de Lencastre
authors.affiliation: Laboratory for Molecular Genetics, Instituto de Tecnologia Química e Biológica, Oeiras, Portugal.|Laboratory of Bacterial Evolution and Molecular Epidemiology, Instituto de Tecnologia Química e Biológica António Xavier, Oeiras, Portugal.
authors.forename: Maria
authors.initials: M
authors.lastname: Miragaia
authors.affiliation: Laboratory for Molecular Genetics, Instituto de Tecnologia Química e Biológica, Oeiras, Portugal.|Laboratory of Bacterial Evolution and Molecular Epidemiology, Instituto de Tecnologia Química e Biológica António Xavier, Oeiras, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Rolo
authors.affiliation: The Wellcome Trust Centre for Human Genetics, Oxford Genomics Centre, Oxford, United Kingdom.
authors.forename: Rory
authors.initials: R
authors.lastname: Bowden
authors.affiliation: Department of Zoology, University of Oxford, Oxford, United Kingdom.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Jolley
authors.affiliation: Department of Zoology, University of Oxford, Oxford, United Kingdom.
authors.forename: Martin C J
authors.initials: MC
authors.lastname: Maiden
authors.affiliation: Medical Microbiology & Infectious Diseases, Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, United Kingdom.|Institut für Medizinische Diagnostik GmbH, Mikrobiologie/Infektiologie, Ingelheim, Germany.
authors.forename: Dietrich
authors.initials: D
authors.lastname: Mack
authors.affiliation: Medical Microbiology & Infectious Diseases, Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, United Kingdom.|MRC CLIMB Consortium, Institute of Life Science, Swansea University, Swansea, United Kingdom.
authors.forename: Samuel K
authors.initials: SK
authors.lastname: Sheppard
mesh_terms: D018441:Biofilms / Q000145:classification / Q000254:growth & development*; D003428:Cross Infection / Q000382:microbiology*; D006801:Humans; D010802:Phylogeny; D013203:Staphylococcal Infections / Q000382:microbiology*; D013212:Staphylococcus epidermidis / Q000235:genetics*