Autor(es): Oliveira, Fernando E. ; França, Angela ; Cerca, Nuno
Data: 2017
Identificador Persistente: https://hdl.handle.net/1822/47542
Origem: RepositóriUM - Universidade do Minho
Projeto/bolsa: info:eu-repo/grantAgreement/FCT/5876/147337/PT; info:eu-repo/grantAgreement/FCT/5876-PPCDTI/126270/PT ; info:eu-repo/grantAgreement/FCT/COMPETE/126270/PT;
Assunto(s): Staphylococcus epidermidis; biofilm formation; iron; Science & Technology
Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.ijmm.2017.08.009.
Staphylococcus epidermidis has long been known as a major bacterial coloniser of the human skin, yet it is also a prominent nosocomial pathogen. Its remarkable ability to assemble structured biofilms has been its major known pathogenic feature to date. Notwithstanding important discoveries that have been accomplished, several questions about S. epidermidis biofilm formation still remain to be elucidated. This study aimed to assess whether iron availability modulates S. epidermidis biofilm formation and, if so, to explore how such modulation occurs. Biofilms of three S. epidermidis strains were grown under iron-enriched/-deficient conditions and several physiologic and transcriptomic changes were assessed. Our data revealed that while physiologic iron levels do not compromise biofilm formation, iron excess or deficiency is detrimental for this process. Conversely, biofilm cells were not affected in the same way when grown planktonically. By studying biofilm cells in detail we found that their viability and cultivability were seriously compromised by iron deficiency. Also, a temporal analysis of biofilm formation revealed that iron excess/deficiency: i) impaired biomass accumulation from 6 h onwards, and ii) induced changes in the biofilm structure, indicating that iron availability plays a pivotal role from an early biofilm development stage. The expression of several putative iron-related genes, namely encoding siderophore biosynthesis/transport-related proteins, was found to be modulated by iron availability, providing a biological validation of their function on S. epidermidis iron metabolism. This study therefore provides evidence that iron plays a pivotal role on S. epidermidis biofilm formation.
This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/ BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER006684) and the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124FEDER-027462). FO and AF acknowledges the Portuguese Foundation for Science and Tecnology for the financial support through the individual grants SFRH/BD/101399/2014 and SFRH/BPD/99961/2014. NC is an Investigador FCT.
info:eu-repo/semantics/publishedVersion
