Application of anti-listerial bacteriocins: monitoring enterocin expression by multiplex relative reverse transcription-PCR.

Listeriosis is a deadly food-borne disease, and its incidence may be limited through the biotechnological exploitation of a number of anti-listerial biocontrol agents. The most widely used of these agents are bacteriocins and the Class II enterocins are characterized by their activity against Listeria. Enterocins are primarily produced by enterococci, particularly Enterococcus faecium and many strains have been described, often encoding multiple bacteriocins. The use of these strains in food will require that they are free of virulence functions and that they exhibit a high level expression of anti-listerial enterocins in fermentation conditions. Multiplex relative RT (reverse transcription)-PCR is a technique that is useful in the discovery of advantageous expression characteristics among enterocin-producing strains. It allows the levels of individual enterocin gene expression to be monitored and determination of how expression is altered under different growth conditions.