We are proposing to design an engineered biosensor model to counter measure for this issue. Our aim is to reduce the virulence of the bacterium by cleaving AHL molecules. To avoid any possible contamination by the biosensor itself, we are adding a kill switch system, consisting of innate CcdA/CcdB type II toxin-antitoxin system to regulate the number of biosensors (Fraikin et al., 2020) in the whole expression cassette. As the concentration of AHL reduces, mass of biofilm reduces and not as many biosensors would be needed. QscR and ccdB toxin are constantly expressed, if QscR cannot detect any AHL molecules, lactonase AiiA and antitoxin CcdA will no longer be released, the bacteria will carry out apoptosis.