Polymerase Chain Reaction Detection of Invasive Shigella and Salmonella enterica in Food

The ability to detect Shigella in foods is often hampered by the often-low numbers of organisms present in the sample at the time of analysis. At present, a reliable, time-efficient, and highly sensitive protocol to isolate Shigella from foods is unavailable although a conventional method is currently described in the Bacteriological Analytical Manual (BAM; 1 ). Through the use of a polymerase chain reaction (PCR)-based assay, many of the problems associated with analyzing food samples for the detection of pathogens can be overcome. The preparation of template DNA from pathogenic bacterial cells in sufficient numbers and free of potential PCR inhibitors is quite difficult, as with any given pathogen in a complex matrix.