title: Evidence for inter- and intraspecies biofilm formation variability among a small group of coagulase-negative staphylococci.
abstract: Coagulase-negative staphylococci (CoNS) are common bacterial colonizers of the human skin. They are often involved in nosocomial infections due to biofilm formation in indwelling medical devices. While biofilm formation has been extensively studied in Staphylococcus epidermidis, little is known regarding other CoNS species. Here, biofilms from six different CoNS species were characterized in terms of biofilm composition and architecture. Interestingly, the ability to form a thick biofilm was not associated with any particular species, and high variability on biofilm accumulation was found within the same species. Cell viability assays also revealed different proportions of live and dead cells within biofilms formed by different species, although this parameter was particularly similar at the intraspecies level. On the other hand, biofilm disruption assays demonstrated important inter- and intraspecies differences regarding extracellular matrix composition. Lastly, confocal laser scanning microscopy experiments confirmed this variability, highlighting important differences and common features of CoNS biofilms. We hypothesized that the biofilm formation heterogeneity observed was rather associated with biofilm matrix composition than with cells themselves. Additionally, our results indicate that polysaccharides, DNA and proteins are fundamental pieces in the process of CoNS biofilm formation.
authors.affiliation: Centre of Biological Engineering, LIBRO-Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Fernando
authors.initials: F
authors.lastname: Oliveira
authors.affiliation: Centre of Biological Engineering, LIBRO-Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Cláudia Afonso
authors.initials: CA
authors.lastname: Lima
authors.affiliation: Centre of Biological Engineering, LIBRO-Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Brás
authors.affiliation: Centre of Biological Engineering, LIBRO-Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Ângela
authors.initials: Â
authors.lastname: França
authors.affiliation: 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
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018441:Biofilms; D003030:Coagulase / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013210:Staphylococcus / Q000145:classification* / Q000201:enzymology / Q000302:isolation & purification / Q000502:physiology*; D055815:Young Adult
chemical_list: D003030:Coagulase
keywords: CLSM; biofilm disruption assays; biofilm formation; coagulase negative staphylococci; flow cytometry