Open AccessTemporal expression of agrB , cidA , and alsS in the early development of S taphylococcus aureus UAMS ‐1 biofilm formation and the structural role of extracellular DNA and carbohydrates
Author(s) -
Grande Rossella,
Nistico Laura,
Sambanthamoorthy Karthik,
Longwell Mark,
Iannitelli Antonio,
Cellini Luigina,
Stefano Antonio,
Hall Stoodley Luanne,
Stoodley Paul
Publication year - 2014
Publication title -
pathogens and disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.983
H-Index - 105
ISSN - 2049-632X
DOI - 10.1111/2049-632x.12158
Subject(s) - biofilm , biology , microbiology and biotechnology , extracellular polymeric substance , virulence , extracellular , extracellular matrix , lysis , gene expression , bacteria , staphylococcus aureus , gene , biochemistry , genetics
Extracellular DNA (e DNA ) is an important component of the extracellular polymeric substance matrix and is important in the establishment and persistence of S taphylococcus aureus UAMS ‐1 biofilms. The aim of the study was to determine the temporal expression of genes involved in early biofilm formation and eDNA production. We used q PCR to investigate expression of agrB , which is associated with secreted virulence factors and biofilm dispersal, cidA , which is associated with biofilm adherence and genomic DNA release, and alsS, which is associated with cell lysis, eDNA release and acid tolerance. The contribution of eDNA to the stability of the biofilm matrix was assessed by digesting with DN ase I (Pulmozyme) and quantifying structure by confocal microscopy and comstat image analysis. AgrB expression initially increased at 24 h but then dramatically decreased at 72 h in an inverse relationship to biomass, supporting its role in regulating biofilm dispersal. cidA and alsS expression steadily increased over 72 h, suggesting that eDNA was an important component of early biofilm development. DN ase I had no effect on biomass, but did cause the biofilms to become more heterogeneous. Carbohydrates in the matrix appeared to play an important role in structural stability.