Scientists at McMaster University in Canada have developed a rapid specific Salmonella Typhimurium assy.  The technology was described in a peer-reviewed article, A Simple Colorimetric Gold-On-Gold Tip Sensor with a new Functional Nucleic Acid Probe for the Foodborne Pathogen Salmonella Typhinurium.

The test relies on components of the Salmonella bacterium interacting with a synthetic nucleic acid that is released only in the presence of the pathogen.  A color reaction develops that is semi-quantitative as indicated by the intensity of the color reaction.