title: New Insights into the Enterococcus faecium and Streptococcus gallolyticus subsp. gallolyticus Host Interaction Mechanisms.
abstract: Enterococcus faecium and Streptococcus gallolyticus subsp. gallolyticus (S. gallolyticus) were classically clustered into the Lancefield Group D streptococci and despite their taxonomic reclassification still share a similar genetic content and environment. Both species are considered as opportunistic pathogens. E. faecium is often associated with nosocomial bacteraemia, and S. gallolyticus is sporadically found in endocarditis of colorectal cancer patients. In both cases, the source of infection is commonly endogenous with a translocation process that launches through the intestinal barrier. To get new insights into the pathological processes preceding infection development of both organisms, we used an in vitro model with Caco-2 cells to study and compare the adhesion, invasion and translocation inherent abilities of 6 E. faecium and 4 S. gallolyticus well-characterized isolates. Additionally, biofilm formation on polystyrene, collagen I and IV was also explored. Overall results showed that E. faecium translocated more efficiently than S. gallolyticus, inducing a destabilization of the intestinal monolayer. Isolates Efm106, Efm121 and Efm113 (p < .001 compared to Ef222) exhibited the higher translocation ability and were able to adhere 2-3 times higher than S. gallolyticus isolates. Both species preferred the collagen IV coated surfaces to form biofilm but the S. gallolyticus structures were more compact (p = .01). These results may support a relationship between biofilm formation and vegetation establishment in S. gallolyticus endocarditis, whereas the high translocation ability of E. faecium high-risk clones might partially explain the increasing number of bacteraemia.
authors.affiliation: Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.|Red Española de Investigación en Patología Infecciosa (REIPI), Sevilla, Spain.
authors.forename: Ana María
authors.identifier: http://orcid.org/0000-0001-5625-6900
authors.initials: AM
authors.lastname: Sánchez-Díaz
authors.affiliation: Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Romero-Hernández
authors.affiliation: Grupo de Biomarcadores y Dianas Terapéuticas, Hospital Universitario Ramón y Cajal and IRYCIS, Madrid, Spain.
authors.forename: Elisa
authors.initials: E
authors.lastname: Conde-Moreno
authors.affiliation: Microbiology Tumor and Cell Biology Department (MTC), Karolinska Institutet, Stockholm, Sweden.
authors.forename: Young-Keun
authors.initials: YK
authors.lastname: Kwak
authors.affiliation: Unidad de Bioestadística Clínica, Hospital Universitario Ramón y Cajal and IRYCIS, Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Zamora
authors.affiliation: Microbiology Tumor and Cell Biology Department (MTC), Karolinska Institutet, Stockholm, Sweden.
authors.forename: Patricia
authors.initials: P
authors.lastname: Colque-Navarro
authors.affiliation: Microbiology Tumor and Cell Biology Department (MTC), Karolinska Institutet, Stockholm, Sweden.
authors.forename: Roland
authors.initials: R
authors.lastname: Möllby
authors.affiliation: Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.|Red Española de Investigación en Patología Infecciosa (REIPI), Sevilla, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Ruiz-Garbajosa
authors.affiliation: Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.|Red Española de Investigación en Patología Infecciosa (REIPI), Sevilla, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Cantón
authors.affiliation: Grupo de Biomarcadores y Dianas Terapéuticas, Hospital Universitario Ramón y Cajal and IRYCIS, Madrid, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: García-Bermejo
authors.affiliation: Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.|Red Española de Investigación en Patología Infecciosa (REIPI), Sevilla, Spain.
authors.forename: Rosa
authors.initials: R
authors.lastname: Del Campo
mesh_terms: D018441:Biofilms; D018938:Caco-2 Cells; D016984:Enterococcus faecium / Q000502:physiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D000070099:Streptococcus gallolyticus / Q000502:physiology*