Bacteriophage As a Food Safety Tool

Bacteriophage are viruses that have evolved to specifically bind and infect their host cells and then rapidly replicate, leading to cell lysis. These properties make them promising agents for both detecting bacteria in factories and food products (biosensors) and eradicating them from the food processing environment (biocontrol). Initially the development of biosensors was seen as the most promising application of phage, but in fact the most number of commercial products have been launched in the area of biocontrol. In this presentation I will review the different applications that have been proposed for biocontrol, including a consideration of the effects of the food matrix and the potential for the development of phage resistance both pre- and post-slaughter. The commercial development of phage-based biosensors has been slower, but commercial products are now beginning to appear. Phage-based detection methods provide an advantage over methods that detect either DNA (e.g. PCR) or proteins (e.g. ELISA assays) alone, in that phage will only detect viable cells. This is important when analysing food or environmental samples, as the manufacturer does not want to detect cells that have been inactivated by either a processing or cleaning step. In this talk I will describe the two major approaches that have been taken to developing phage-based biosensors (GM and non-GM), and discuss the pros and cons of each route for routine application in the food industry, including the need for enrichments to reach the desired level of sensitivity (1 cell per 25 g food) and the problem of introducing GM reagents in to food microbiology labs for routine analysis. However, I will also show how new approaches have started to address these problems an there is now potential that phage can be employed to solve specific problems and improve food safety.