Listeria monocytogenes (Lm) is a foodborne pathogenic bacterium that can cause serious illness and even death in susceptible individuals. Outbreaks involving this pathogen have been associated with fruits, sprouts and vegetable row crops. Like most other bacteria, Lm can form biofilms or became part of biofilms with other bacteria on produce surfaces and surfaces in produce harvesting and processing environments. Once established in a biofilm, Lm has highly diminished susceptibility to antimicrobial agents and is difficult to eradicate. Cells surviving in such biofilms can detach and be carried to new surfaces where they can start the formation of a new biofilm or become part of an existing biofilm. It is therefore extremely important to prevent the transfer of cells from existing biofilms to previously uncontaminated surfaces on produce or processing equipment. The proposed study will examine the efficacy of antimicrobial agents to inactivate Lm released from existing biofilms and prevent the formation of new Lm-containing biofilms on produce and equipment surfaces.