Team:Groningen:Project:Detection/staphaureus

The quorum sensing system in Staphylococcus aureus consist of four genes. These genes are controlled by leaky inducible promoter (P2), and encode for two membrane proteins (AgrB and AgrC), one regulator protein (AgrA) and a precursor peptide (AgrD). The membrane protein AgrB cleaves the precursor peptide AgrD so the mature signaling peptide is formed. The mature signal peptide is called autoinducing peptide (AIP). After the AIP is secreted from the cell it is able to bind to the second membrane protein AgrC. After the binding the AgrC phosphorylates AgrA, AgrA is able to induce the P2 promoter which leads to increased production of the AIPs.

In our LactoAid we introduced the DNA encoding for the membrane protein AgrC and the regulator protein ArgA. When Staphylococcus aureus starts to produce the AIPs, the LactoAid is able to sense the molecules via the same system the S. aureus uses.