Role of sarA and agr in Insulin Modulation of Staphylococcus aureus Biofilm Formation

The focus of this study is to determine whether insulin, quorum signaling and biofilm formation are under regulation of agr and sarA regulation.  Deletion strains agr-, sarA -, and agr-sarA- as well as their parent strain 8325-4 were tested with and without glucose (0.1% and 0.2%) and/or physiologic levels of insulin (2µU/mL, 20µU/mL, and 200µU/mL). In the absence of sarA and agr, there was a marked suppression of biofilm levels in the presence of insulin, indicating that insulin modulation of biofilm formation appears to be regulated, in part, by sarA and agr.