title: Characterization of an in vitro fed-batch model to obtain cells released from S. epidermidis biofilms.
abstract: Both dynamic and fed-batch systems have been used for the study of biofilms. Dynamic systems, whose hallmark is the presence of continuous flow, have been considered the most appropriate for the study of the last stage of the biofilm lifecycle: biofilm disassembly. However, fed-batch is still the most used system in the biofilm research field. Hence, we have used a fed-batch system to collect cells released from Staphylococcus epidermidis biofilms, one of the most important etiological agents of medical device-associated biofilm infections. Herein, we showed that using this model it was possible to collect cells released from biofilms formed by 12 different S. epidermidis clinical and commensal isolates. In addition, our data indicated that biofilm disassembly occurred by both passive and active mechanisms, although the last occurred to a lesser extent. Moreover, it was observed that S. epidermidis biofilm-released cells presented higher tolerance to vancomycin and tetracycline, as well as a particular gene expression phenotype when compared with either biofilm or planktonic cells. Using this model, biofilm-released cells phenotype and their interaction with the host immune system could be studied in more detail, which could help providing significant insights into the pathophysiology of biofilm-related infections.
authors.affiliation: CEB-Centre of Biological Engineering, LIBRO-Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
authors.forename: Angela
authors.initials: A
authors.lastname: França
authors.affiliation: CEB-Centre of Biological Engineering, LIBRO-Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal.|ICBAS-Instituto de Ciências Biomédicas de Abel Salazar, 4050-313, Porto, Portugal.
authors.forename: Virgínia
authors.initials: V
authors.lastname: Carvalhais
authors.affiliation: ICBAS-Instituto de Ciências Biomédicas de Abel Salazar, 4050-313, Porto, Portugal.|Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.|IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.
authors.forename: Manuel
authors.initials: M
authors.lastname: Vilanova
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Gerald B
authors.initials: GB
authors.lastname: Pier
authors.affiliation: CEB-Centre of Biological Engineering, LIBRO-Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal. nunocerca@ceb.uminho.pt.
authors.forename: Nuno
authors.initials: N
authors.lastname: Cerca
keywords: Antibiotic-tolerance; Biofilm-released cells; Biofilms; Fed-batch systems; Gene expression; S. epidermidis